ORIGINAL CONTRIBUTION appendicitis, pediatric
Clinical Features of Misdiagnosed Appendicitis in Children Study objective: To compare clinical features of children with misdiagnosed appendicitis with those of children with appendicitis initially diagnosed correctly. Design: Retrospective review of hospital, emergency department, and clinic records. Setting: University medical center with annual ED census of 40,000 patien ts. Participants: Children less than i3 years old admitted between May 1, 1979, and April 30, 1989, with a discharge diagnosis of appendicitis. Measurements: Records were reviewed for historical, physical examination, laboratory, and pathologic features for all patients on their initial presentation to a physician and on final presentation during which the correct diagnosis was made. Using X2 analysis and Student's t test, clinical features of misdiagnosed patients and patients diagnosed correctly were compared. Results: One hundred eighty-one cases were identified with 50 initially misdiagnosed. On initial presentation, misdiagnosed patients were younger and more likely to have vomiting before pain onset, constipation, diarrhea, dysuria, and signs and s y m p t o m s of upper respiratory infections. Misdiagnosed cases were less likely to have right lower quadrant tenderness and documentation of bowel sounds, peritoneal signs, and rectal examinations. On final presentation, misdiagnosed patients were more likely to have pain duration of more than two days, temperature of more than 38.3 C, and to appear lethargic and irritable (P < .05 for all measurements). Conclusion: Clinical features of children with misdiagnosed appendicitis differ from those of children with appendicitis initially diagnosed correctly. [Rothrock SG, Skeoch G, Rush JJ, Johnson NE: Clinical features of m i s d i a g n o s e d appendicitis in children. A n n Emerg M e d January 199i;20:45-50.]
Steven G Rothrock, MD* Graydon Skeocht John J Rush, MD* N Eric Johnson, MD, MPH, FACEP* Loma Linda, California From the Department of Emergency Medicine, Loma Linda University Medical Center;* and the Loma Linda University School of Medicine,t Loma Linda, California. Received for publication March 19, 1990. Revision received August 8, 1990. Accepted for publication August 24, 1990. Presented at the Society for Academic Emergency Medicine Annual Meeting in Minneapolis, May 1990. Address for reprints: Steven G Rothrock, MD, Department of Emergency Medicine, Loma Linda University Medical Center, 11234 Anderson Street, Loma Linda, California 92350.
INTRODUCTION Diagnosing appendicitis in children can be difficult and challenging. This difficulty is underscored by the fact that misdiagnosed cases of pediatric appendicitis are associated with corresponding increased rates of perforation, abscess formation, wound infections, and deathJ -is In addition to the increased incidence of medical complications, misdiagnosis is associated with a significant risk of litigation. Prior studies have noted that misdiagnosed appendicitis is the most frequent successful malpractice claim and the fifth most expensive cause of claims against emergency physicians.t6, lz Despite the medical and legal risks, missing cases of appendicitis in children remains a common problem. 5,12 This study was performed in an attempt to identify clinical features of pediatric appendicitis that differed between cases initially misdiagnosed and those diagnosed on the first physician encounter. METHODS The study population comprised all children less than 13 years old admitted to a large university medical center between May 1, 1979, and April 30, 1989, with a discharge diagnosis of appendicitis. Patients were divided
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Annals of Emergency Medicine
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APPENDICITIS Rothrock et al
into two groups. The study group comprised all patients who had been seen by a physician within ten days of the correct diagnosis of appendicitis with the same complaints and initially misdiagnosed. The control group comprised all.patients who had been diagnosed correctly at their first physician encounter. Using the ED history and physical examination on final presentation or the admission history and physical examination if patients were transferred from another facility, 28 historical, physical examination, laboratory, and pathologic features were recorded for each patient. Whenever possible, the initial records (ie, from prior clinic or ED visit) on patients initially misdiagn0sed also were reviewed for the same 28 clinical features. Using the Student's t test and X2 analysis (with significance at P < .05), the incidence of clinical features of the control group was compared with that of the study group on initial presentation. Clinical features of the control group were also compared with those of the study group on final presentation. For patients admitted to the hospital with a misdiagnosis and later found to have appendicitis, the initial history and physical examination were used to record clinical features for the initial and final presentations. The incidence of each feature was calculated by dividing the total number of patients with documentation of the presence of a feature by the total number of patients in the group rather than by the total number of patients with documentation of the presence or absence of a particular clinical feature. Incidence of features that were dependent on the presence of a particular sign or symptom (including vomiting before or after pain onset or pain duration of less than or more than two days) was calculated by dividing the total number of patients with the dependent feature by the total number of patients with documentation of the presence or absence of that particular sign or symptom. Incidence of laboratory and radiographic features was calculated by dividing the total number of patients with a positive value by the total number of patients who had that test performed because the number of patients who had each test performed ~vas known. The misdiagnosis and location of 20:1 January 1991
physician who initially saw the patient was also recorded when available for each patient in the study group. Specialty of p h y s i c i a n involved with the initial misdiagnosis was not recorded because information regarding board certification and specialty training was unavailable for the majority of physicians. For each clinical feature in the study and control groups, the rate of documentation of the presence or absence of the feature was recorded. Using ×2 analysis (with significance at P < .05), rates Of documentation of the presence or absence of each clinical feature in the study group were compared with those in the control group on initial and final presentation.
TABLE 1. Initial diagnoses in patients with missed appendicitis Diagnosis Gastroenteritis Unspecified Upper respiratory infection Pharyngitis Otitis media Lower respiratory infection Pneumonia Bronchiolitis Sepsis Urinary tract infection Encephalitis or encephalopathy Febrile seizure Blunt abdominal trauma
No. of Patients 21 11 9 6 3 2 1 1 2 2 1 1 1
% 42 22 18
4
4 4 2 2 2
RESULTS T h e r e were 181 p a t h o l o g i c a l l y proven cases of appendicitis between May l, 1979, and April 30, 1989. Of these , 50 (28%) were classified as misdiagnoses. Records of the final presentation were available for all misdiagnosed cases. Records of the initial presentation were available for 30 of the misdiagnosed cases. Twelve of the initial misdiagnoses (24%) occurred during the same admission to the hospital in w h i c h the correct diagnoses were ultimately made. The most c o m m o n misdiagnoses were gastroenteritis and upper respiratory infections; other misdiagnoses are listed (Table 1). Initial misdiagnoses occurred at a pediatric clinic (or office) in 21 cases (42%), an ED in 15 cases (30%), and a family practice office in one case (2%). No location was specified in 13 cases (26%). On initial presentation, patients with missed appendicitis were more likely to have younger mean age (5.3 vs 7.9 years), vomiting before pain o n s e t (29% vs 8%), c o n s t i p a t i o n (13% vs 5%), dysuria (20% vs 4%), diarrhea (37% vs 10%), upper respiratory symptoms (27% vs 2%), signs of upper respiratory infections (23% vs 2%), and lethargy or irritability (40% vs 9%). On initial presentation, patients with missed appendicitis were less likely to have abdominal tenderness (50% vs 100%) and altered bowel sounds (17% vs 55%). Sex, duration of pain, complaints of fever and abdominal pain, presence of temperature of more than 38.3 C, radiographic findings, mean white blood cell count, and urinalyses also did Annals of Emergency Medicine
n o t differ s i g n i f i c a n t l y b e t w e e n groups on initial presentation (Table
2). On final p r e s e n t a t i o n , p a t i e n t s with missed appendicitis were more likely to have younger mean age (5 vs 7.9 years), pain duration of more than two days (76% vs 41%), vomiting before pain onset (33% vs 8%), constipation (18% vs 5%), diarrhea (28% vs 10%), and respiratory symptoms (28% vs 2%). Study group patients were also more likely to have temperatures of more than 38.3 C (62% vs 26%), lethargy or irritability (56% vs 9%), and upper respiratory infections (30% vs 2%). Study group patients were less likely to have maximal tenderness in the right lower quadrant on final presentation (70% vs 92%). Mean total white count, urinalyses, and abdominal radiographic findings did not differ significantly between groups. Patients with missed appendicitis were also more likely to have perforation and abdominal abscess formation on surgical and pathologic e x a m i n a t i o n (Table 3). On initial presentation, misdiagnosed patients were less likely than control group patients to have documentation of the presence or absence of abdominal pain (87% vs 98%), history of fever (67% vs 86%), constipation (37% vs 77%), and diarrhea (43% vs 88%). Physical findings less likely to be documented in misdiagnosed patients included ears, nose, and throat examinations (63% vs 98%), bowel sounds (70% vs 100%), 46/69
APPENDICITIS Rothrock et al
TABLE 2. Comparison of clinical features of initial presentation Missed Appendicitis (N = 30) No. 0t Patients % Mean age (_+ SD yr) Sex (M/M + F)
5.3 ÷ 3.6
Simple Appendicitis (N - 131) No. of Patients % (100)5
7.9 _+ 2.8
pt (100)
< .005
17/30
57 (100)
70/131
53 (100)
NS
26/30
87
25/131
91
NS
15/26
58
74/125
59
11/26
42
51/125
41
Fever
17/30
57
(67)
74/13i
56
(86)
Vomiting
24/30
80
(97)
109/131
83
(96)
7/24
29
9/109
8
17/24
71
100/109
92
15/30
50
88/131
67
Dysuria
6/30
20
(40)
5/131
4
(53)
< .01
Constipation
5/30
17
(37)
6/131
5
(77)
< .05
11/30
37
(43)
13/131
10
(88)
< .005
8/30
27
(33)
3/131
2
(41)
< .005
Symptoms Abdominal pain
(87)
(98)
Pain duration 0
2 days
> 2 days
Before pain onset After pain onset or concurrently or unknown timing Poor feeding
Diarrhea Upper and lower respiratory symptoms
(70)
NS NS NS NS < .01 < .01 (85)
NS
Signs Temperature > 38.3 C
7/30
23
(90)
34/131
26
(99)
NS
Irritability or lethargy
12/30
40
(37)
12/t31
9
(62)
< .005
Ears, nose, and throat infection
7/30
23
(63)
2/131
2
(98)
< .005
Altered bowel sounds
5/30
17
(70)
72/131
55
(100)
< .005
(100)
Maximal tenderness
(100)
43
120/131
92
2/30
7
11/131
8
15/30
50
0
Right lower quadrant*
13/30
Other than right lower quadrant Nontender Peritoneal signs
0/30
0
(10)
65/131
50
(96)
< .005
Rectal tenderness
0/30
0
(13)
18/131
14
(50)
NS
< .005
13,400 +_ 5,300
(67)
16,900 + 6,700
(98)
NS
NS < .005
Laboratory Features Total WBCs UrinalYsis WBCs or RBCs/hpf > 5
(77) 3/23
8
(84) 8/11.0
7
(33)
Radiographs
NS (48)
Normal
7/10
70
30/63
48
NS
Abnormal
NS
3/10
30
33/63
52
Suggestiveof appendicitis
1/10
10
14/63
22
Not specific for appendicitis
2/10
20
19/63
30
63
29/131
22
Palholooy Perforation Retrocecal or abnormal location
(100) 19/30
(100) < .005
2/30
7
7/13i
5
NS
Abdominal abscess
8/30
27
5/131
4
< .005
Mortality
2/30
7
NS
*Included were patients with diffuse or bilateral lower quadrant tenderness as long as right lower quadrant tenderness was documented to be at least as maximal as tenderness at other sites. tp value is derived from Student's t test for mean age and WBC count; all ether P values are derived from X 2 analysis. :~Numbers in parentheses indicate rate of documentation of presence or absence of clinical featul-e.
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peritoneal signs (10% vs 96%), and rectal examinations (13% vs 50%)(P < .01 for all comparisons). On final presentation, misdiagnosed patients were less likely to have d o c u m e n t a t i o n of peritoneal signs (74% vs 96%) and more likely to have abdominal radiography performed (74% vs 48%). Rates of documentation of all other clinical features were not significantly different between study and control groups on final presentation (P < .01 for all comparisons).
Annals of Emergency Medicine
DISCUSSION The diagnosis of appendicitis in children is generally considered more difficult than in adults: is Children are more likely to have symptoms for a longer period of time before a correct diagnosis is made than are adults and are more likely to suffer from the complications of perforation, abscess formation, peritonitis, and death. 19-27 Prior studies have noted that the detection of appendicitis in Children is often delayed due to misdiagnosis by physicians.~-]5 Reported rates of misdiagnosis vary from 7.5% to 12% for children less than 15 years old and are as high as 57% for children less than six years old. 5,6,9 Our misdiagnosis rate of 28% lin all patients less than 13 years old) is consistent with these prior studies. This misdiagnosis rate, however, may be misleading because the study facility is a tertiary-care hospital w i t h pediatric surgical specialists. Thus, more complicated cases (and possibly more pat i e n t s w h o are i n i t i a l l y m i s d i a g nosed) might be transferred to this facility. In addition, this misdiagnosis rate does not take into consideration patients who were misdiagnosed at the study facility and later diagnosed at another facility because of the difficulty in identifying this class of patients. Although a significant physician-caused delay due to misdiagnosis has been well documented in the l i t e r a t u r e , no studies have attempted to determine whether differing clinical features contribute to misdiagnosis, Our study compared incidences of historical, physical, laboratory, and pathologic features of children with misdiagnosed appendicitis with those of children with appendicitis diagnosed correctly at the first physician encounter to det e r m i n e w h e t h e r d i f f e r i n g clini20:1 January 1991
APPENDICITIS Rothrock et al
cal features were associated w i t h misdiagnosis. In our study, misdiagnoses did not differ significantly from prior reports of missed cases of appendicitis. As in prior studies, we found gastroenteritis to be the most common misdiagnosis.S,7,9,12 The reasons for this are apparent as b o t h disease processes cause abdominal pain, vomiting, and varying degrees of tempera~ ture elevation. However, upper respiratory infections were also found to be a c o m m o n misdiagnosis in our study. The reasons for this misdiagnosis are less Clear because the constellation of signs and symptoms with each disease process do not overlap. Of the other misdiagnoses (Table 1), urinary tract infections, meningitis, encephalitis~ febrile seizures, sepsis, and p n e u m o n i a have been reported as erroneous diagnoses in p a t i e n t s with appendicitis.3,s,7,9-12, 28 However, no prior cases of appendicitis misdiagnosed as blunt abdominal trauma could be found in the literature. Other reported misdiagnoses not found in our study include right hip septic arthritis, testicular torsion, bowel obstruction, inflammatory bowel disease, dehydration, and cholecystitis.5,7,9,m,29 Primary-care facilities (pediatric clinics and EDs) were responsible for the majority of misdiagnosed cases of appendicitis in our study. No comment can be made concerning the training or board certification of physicians involved with misdiagnosis because information regarding specialty training and board certification was unavailable for the majority of physicians. In addition, during the first few years of the study period, board-certified emergency physicians were rare because this specialty was formed during the late 1970s. The preponderance of primary-care facilities (or physicians) involved with the m i s d i a g n o s i s of p e d i a t r i c appendicitis may be more of a reflection of the large numbers of patients with abdominal complaints seen at these locations than of any i n a d e q u a t e training or experience of physicians working at these locations. It should also be noted that the specialties of general surgery, urology, and gynecology were involved as c o n s u l t a n t s with cases initially misdiagnosed. Regardless of location or specialty, physicians involved with the care of children should be made aware of the 20:1 January 1991
TABLE 3. Comparison of clinical features
on
Missed Appendicitis (N = 30) No, of Patients % 5 ± 3.2
Mean age (± SD yr)
final presentation Simple Appendicitis (N = 131) No. of Patients %
(100);
7.9 + 2.6
pt (100)
28/50
56
(100)
70/131
41/50
82
(96)
125/131
95
0 - 2 days
10/41
24
74/125
59
< .005
> 2 days
31/41
76
51/125
41
< .005
Sex (M/M + F)
53 (100)
< .005 NS
Symptoms Abdominal pain
(98)
< .01
Pain duration
Fever
37/50
74
(96)
74/131
56
(86)
Vomiting
42/50
84
(98)
109/131
83
(96)
< .05
Before pain onset
14/42
33
9/109
8
< .005
After pain onset or concurrently or unknown timing
28/42
67
100/109
92
< .005
NS
35/50
70
(80)
88/131
67
(85)
Dysuria
3/50
6
(46)
5/131
4
(53)
NS
Constipation
9/50
18
(78)
6/131
5
(77)
< .01
Diarrhea
14/50
28
(88)
13/131
10
(88)
< .005
Upper and lower respiratory symptoms
14/50
28
(52)
3/131
2
(41)
< .005
Signs Temperature > 38.3 C
31/50
62
(98)
34/131
26
(99)
< .005
Irritability or lethargy
28/50
56
(70)
12/131
9
(62)
< .005
Ears, nose, and throat infection
15/50
30
(94)
2/131
2
(98)
< .005
Altered bowel sounds
30/50
60
(100)
72/131
55
(100)
NS
35/50
70
120/131
92
Other than right lower quadrant
7/50
14
11/131
8
Nontender
8/50
16
0
Peritoneal signs
18/50
36
(74)
65/131
50
(96)
NS
Rectal tenderness
12/50
24
(46)
18/131
14
(50)
NS
16,900 ± 6,700 (100)
NS
Poor feeding
(100)
Maximal tenderness Right lower quadrant*
NS
(100) < .005 NS < .005
Laboratory Features Total WBCs
16,700 ± 6,600 (100) (88)
Urinalysis 6/44
WBCs or RBOs/bpf > 5
14
(84) 8/110
7
(74)
Radiographs
NS (48)
Normal
15/37
40
30/63
48
NS
Abnormal
22/37
60
33/63
52
NS
9/37
24
14/63
22
13/3"7
35
19/63
36
Suggestive of appendicitis Not specific for appendicitis
(100)
NS (100)
Pathology Perforation Retrocecal or abnormal location
26/50
52
29/131
22
4/50
8
7/131
5
NS
Abdominal abscess
10/50
20
5/131
4
< .005
2/50
4
Mortality
0
< ,005
NS
*Included were patienls with diffuse or bilateral lower quadrant tenderness as long as right lower quadrant tenderness was documented to be at least as maximal as tenderness at other sites. tp value is derived from Studenl's t test for mean age and WBC counl; all other P values are derived from x 2 analysis• ;Numbers in parentheses indicate rate of documentation of presence or absence of clinical feature•
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APPENDICITIS Rothrock et al
high incidence of missed appendicitis in younger age groups. Several potential reasons for misdiagnoses exist in children with appendicitis. Younger children are less able to verbalize their complaints to physicians. Because of difficulties with communication, interpretation of physical examination findings also becomes more difficult. This difficulty may in part explain why almost half (43%) of misdiagnosed patients in our study had maximal tenderness including the right lower quadrant on initial examination and were still thought to have a nonsurgical abdomen. It appears that in these patients, p h y s i c i a n s either disregarded this finding or thought that it was insignificant, whereas it was an important clue to the early diagnosis of appendicitisl Several a u t h o r s stress that the presence of right lower quadrant tenderness is probably the most sensitive physical finding in early appendicitis. 13,3°-33 At the very least, patients with maximum tenderness in the right lower quadrant who are suspected of having a benign intraabdominal process should be reassessed within a short time period with consideration of hospital admission and surgical consultation if the patient's clinical picture becomes more suspicious. An alternative in equivocal cases, if readily available, is ultrasound, which has a nearly 90% sensitivity in diagnosing appendicitis.34, 35 The presence of atypical signs and symptoms may also have dissuaded physicians from considering the diagnosis of appendicitis in several cases. Alterations of bowel habits, including constipation and diarrhea, were more c o m m o n in the study group than i,n the c o n t r o l group. Prior studies have noted a 9% to 33% incidence of constipation and a 10% to 33% incidence of diarrhea in children w i t h a p p e n d i c i t i s . g , 6 j , lo, is, 2o,~1,3o Although diarrhea secondary to gastroenteritis or to constipation can give rise to abdominal discomfort, neither typically causes localized right lower quadrant tenderness, peritoneal signs, or rectal tenderness. If any of these physical findings are present, c o n s i d e r a t i o n should be given to a surgical cause for abdo.minal pain: In addition to altered bowel habits, patients with missed appendicitis 72/49
were more likely to have vomiting that preceded the onset of abdominal pain than were patients with simple appendicitis. It is widely taught that the large majority of patients with appendicitis have onset of vomiting after their pain begins.18,36, 3z One possible explanation for the discrepancy between our results and this classic teaching is that young children are less able to verbalize their feelings. Parents may have first noticed that there was a problem only after their child vomited. Thus, pat i e n t s m a y have had pain before vomiting that was not noticed by their parents. Respiratory symptoms were also noted to be more c o m m o n in the s t u d y group than in the c o n t r o l group. The association of respiratory infections and appendicitis has been noted by prior authors who have reported a higher incidence of both diseases during the winter and spring and have postulated that similar etiologic agents may be involved.19, 38,39 Reasons for this association are unclear. However, upper and lower respiratory infections often coexist in patients with appendicitis.7,1O-l~, ~8, 38,39 Although it is widely taught that basilar pneumonias can mimic appendicitis, physicians should not let concurrent upper or lower respiratory infections stop them from considering the diagnosis of appendicitis in children with other suggestive clinical features. 18,36,37,4° Dysuria was another clinical feature that occurred with a higher frequency in the study group. Dysuria reportedly occurs in 7% to 15% of patients with appendicitis, whereas an abnormal urinalysis (more than 5 WBCs or RBCs per high-power field) is present in as many as 30% of patients, lS,2O,41 Because of its proximity to the ureter, an inflamed appendix lying in the pelvis can cause irritation and dysuria in addition to abnormal urinalyses. Although patients in the study group were more likely to have dysuria, the incidence of positive urinalyses was similar in the two groups. Another factor other than atypical clinical features in misdiagnosed cases was poor d o c u m e n t a t i o n of physical findings. Although the majority of patients with missed appendicitis had vomiting and abdominal pain and all had one of these sympt o m s , d o c u m e n t a t i o n of b o w e l Annals of Emergency Medicine
sounds, peritoneal signs, and rectal examinations was poor. No explanation can be given for the lack of docu m e n t a t i o n of bowel sounds and peritoneal signs in patients with vomiting and abdominal pain. Also disturbing is that CBCs (obtained in 67% of cases), urinalyses (obtained in 77% of cases), and radiographs (obtained in 33% of cases) were performed (or at least documented) more often than rectal examinations (13%) on initial presentation. Normal radiographs and WBC counts may have falsely reassured physicians that patients had benign causes for their a b d o m i n a l complaints. Even though some physicians believe that they gain little information from performing rectal examinations ( e s p e c i a l l y in a frightened, apprehensive child), they should be aware that 50% to 80% of children w i t h a p p e n d i c i t i s (even those less than 6 years old) have lo~ calized rectal tenderness, and as many as 25% have palpable masses rectally.l,21, 26 Physicians may diagnose a case of appendicitis that they might have otherwise missed by performing a rectal examination. Morbidity from missed cases of appendicitis was significant. On final presentation, patients appeared to be more ill than in the control group. They were more likely to be irritable, lethargic, and febrile with temperature of more than 38.3 C. Duration of symptoms also was longer than in control patients. Complications of perforation and intra-abdominal abscess formation were more prevalent in the study group. The only two deaths occurred in the study group, although mortality rates were not statistically different between groups. Atypical clinical features seen on initial presentation also were noted on final presentation, including dysuria, constipation, diarrhea, respiratory symptoms, signs of respiratory infections, irritability, lethargy, and less-frequent right lower quadrant tenderness. It is possible with the increased incidence of these features on initial and final presentation compared with the control group that patients with misdiagnosed appendicitis are not patients early in the course of their disease who have not'yet manifested all of the typical clinical features of appendicitis; they appear to be an entirely different population with dif20:1 January 1991
APPENDICITIS Rothrock et al
feting clinical features. A large number of children with appendicitis may be misdiagnosed because of their atypical clinical features. There are several limitations that should be acknowledged in reviewing the results of this study. Selection of patients for study may have been flawed. The study hospital is a tertiary-care facility with pediatric surgical specialists. Thus, there is a possibility that more complicated cases that may have been misdiagnosed at outlying hospitals without pediatric surgical specialists were transferred to this facility, resulting in a higher rate of atypical cases and misdiagnosis. Due to the retrospective nature of data collection, it was also not possible to determine whether signs and s y m p t o m s not recorded were present. The incidence of each feature was calculated by dividing the total number of patients with a particular feature present by the total number of patients in the group rather than by the total number with documentation of the presence or absence of this feature. This method was chosen to determine incidence because the authors believed that features not documented (in either a positive or negative manner) were likely to be absent or less significant to the examining physician or patient. This technique might potentially lower the incidence of certain clinical features because it essentially categorizes features that were not documented in either a positive or negative fashion as absent. However, the alternate method of calculating the incidence of clinical features by dividing the number of patients with a feature documented as present by the total number with that feature documented as present or absent is also flawed because it assumes that the rates of documentation of features will be similar for features that are present and absent. Regardless of the method used, calculating the incidence of each clinical feature is dependent on chart documentation that is nonstandardized and incomplete. CONCLUSION A retrospective study was performed to compare clinical features
20:1 January 1991
of patients with misdiagnosed appendicitis with those of patients diagnosed correctly at the first physician encounter. Patients with misdiagnosed appendicitis were found to be younger and have more atypical symptoms on initial and final presentation, including v o m i t i n g before pain onset, dysuria, constipation, diarrhea, and upper respiratory symptoms. They were also more likely to have physical findings of upper respiratory i n f e c t i o n s , lethargy, irritability, normal bowel sounds, and non-right lower quadrant tenderness. Documentation of abdominal findings and rectal examination was less common in patients with missed appendicitis on their first presentation to a physician. Physicians should be aware that atypical signs and symptoms are often associated with missed cases of appendicitis. Physicians caring for children should be alert to the atypical clinical features and many pitfalls to be avoided in diagnosing appendicitis in younger age groups. REFERENCES
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Emerff Med 1984; 13:709-711. 17. Rogers JT: Foresight: High risk loss prevention. ACEP News December 1986. 18. Condon RE: Appendicitis, in Sabiston DC (ed): Textbook of Surgery, ed 13. Philadelphia, WB 8aunders, 1986, p 972-973. 19. Abel WG, Allen PD: Acute appendicitis in children. Ann Surg 1950;132:1093 1102. 20. Blair GL, Gaisford WD: Acute appendicitis in chil dren under 6 years. J Pediatr Surg 1969;4:445-451. 21. Brickman ID, Leon W: Acute appendicitis in childhood. Pediatr Surg 1960;5:I083-1089. 22. Deaver JM: Acute appendicitis in children. Ann Surg 1952;136:243 249. 23. Gilbert 8R, Emmens RW, Putnam TC: Appendicitis in children. Surg Gyneco] Obstet 1985;161:261 265. 24. Janik J8, Firor HV: Pediatric appendicitis: A 20 year study of 1,640 children at Cook County Hospital. Arch Surg i979;114:717-719. 25. Longino LA, Holder TM, Gross RE: Appendicitis in childhood: A study of 1,358 cases. Pediatrics 1958; 22:238-246. 26. Sadrieh M, Farpour A: Acute appendicitis: Review of 970 cases. A m J Proctol 1975;26:51-56. 27. Sethi 8M, Matsuda T, Pemberton B, et aI: An analysis of 500 consecutive cases of acute appendicitis in a m e t r o p o l i t a n c h a r i t y h o s p i t a l . Ill Med J 1970;138: 147-149. 28. iona JZ, Belin RP: Basilar pneumonia simulating acute appendicitis in children. Arch 8urg 1976~111: 552-553.
1. Bartlett RH, Eraklis AJ, Wilkinson RH: Appendicitis in infancy. Surg Gyneco] Obstet 1970;130:99-105.
29. Nagel P: Scrotal swelling as the presenting symptom of acute perforated appendicitis in an infant. J Pediatr 8urg 1984~19:177.
2. Brender JD, Mareuse EK, Koepsell TD, et al: Childhood appendicitis: Factors associated with perforation. Pediatric~s 1985;76:301-306.
30. Rowa MI: Diagnosis and treatment: Appendicitis in childhood. Pediatrics 1966;38:1057-1059.
3. Daehlin L: Acute appendicitis during the first three years of life. Acta Chir Stand 1982;148:291-294.
31. Alvarado A: A practical score for the early diagnosis of acute appendicitis. Ann Emerg Med 1986;15:557-564.
4. Ferguson E, Pirrung D: Acute appendicitis: Clinical vs pathologic diagnosis. A m J Procto] 1969;20:269-278.
32. Lewis FR, Holcroft JW, Boey J, et al: Appendicitis: A critical review- of diagnosis and t r e a t m e n t in 1,000 cases. Arch 8urg 1975;110:677-684.
5. Golladay ES, Sarrett JR: Delayed diagnosis in pedi attic appendicitis. South Med J 1988;81:38-41. 6. Graham JM, Pokorny WJ, Harberg FI: Acute appendicitis in preschool age children. A m J 8urg 1980;139: 247 250. 7. Grosfeld JL, Weinberger M, Clatworthy HW: Acute appendicitis in the first two years of life. J Pediatr Surg 1973;8:285-292. 8. Harrison MW, Lindner DJ, Campbell JR, et ah Acute appendicitis in children: Factors affecting morbidity. A m J Surg I984;147:605~610. 9. Lay YW, Fan ST, Yip CW, et ah Acute appendicitis in children. N Z J Surg I987;57:927-931. 10. Purl P, O'Donnell RB: Appendicitis in infancy. J Pediatr Surg 1978;13:173-174. lh Rappaport WD, Peterson M, Stanton C: Factors responsible for the high perforation rate seen in early childhood appendicitis. A m Surg 1989;56:602-605. 12. Savarin RA, Clatworthy HW: Appendicea] rup~,ure: A continuing diagnostic problem. Pediatrics 1979;63: 37-43. 13. Stanley-Brown EG: Acute appendicitis during the first five years of life. A m J Dis Child 1964~108:i34-138. 14. Stone HH, Sanders SL, Martin JD: Perforated appen dicitis in children. Surgery 1971;69:673-679. 15. Williams H: Appendicitis in the young. Br Med J
Annals of Emergency Medicine
33. McFee AS, Rogers W: Diagnosing appendicitis in the pediatric patient. Infect Surg I982;42-49. 34. Puylaert JBCM, Rutgers PH, Lalisang RI, et ah A p r o s p e c t i v e study of u l t r a s o n o g r a p h y the diagnosis of
appendicitis. N Engl J Med 1987~317:666-669. 35. Larson JM, Peirce JC, Ellingcr DM: The validity and utility of sonography in the diagnosis of appendicitis in the community setting. A m J Roent 1989;153:687-689. 36. Silen W (ed): Cape's Early DiGgnosis of the Acute Abdomen. New York, Oxford University Press, Inc, 1987, p 66-106. 37. Boniface KJ, Spadafora MP: Disorders of the small intestine, in Rosen P fed): Emergency MedJcYne: Concepts and Clinical Practice. St Louis, CV Mosby, 1988, p 1459-i478. 38. Benson CD, CouP/JJ, Hagge DR: Acute appendicitis in infants. Arch Surg 1952;64: 561-570. 39. Winsey H8, Jones PP: Acute abdominal pain in children: Analysis of a year's admissions. Br Med ] 1967; 1:653 655. 40. 8chnaufer L, Mahboubi: Abdominal emergencies, in Fleishcer GR, Ludwig 8 [eds): Textbook of Pediatric Emergency Medicine. Baltimore, Williams & Wilkins, 1988, p 936 965. 41. Scott JH, Amin M, Harry JI: Ahnormal urinalysis in appendicitis. J Urology 1983;129:1015.
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Clinical Features of Misdiagnosed Appendicitis in Children Study objective: To compare clinical features of children with misdiagnosed appendicitis with those of children with appendicitis initially diagnosed correctly. Design: Retrospective review of hospital, emergency department, and clinic records. Setting: University medical center with annual ED census of 40,000 patien ts. Participants: Children less than i3 years old admitted between May 1, 1979, and April 30, 1989, with a discharge diagnosis of appendicitis. Measurements: Records were reviewed for historical, physical examination, laboratory, and pathologic features for all patients on their initial presentation to a physician and on final presentation during which the correct diagnosis was made. Using X2 analysis and Student's t test, clinical features of misdiagnosed patients and patients diagnosed correctly were compared. Results: One hundred eighty-one cases were identified with 50 initially misdiagnosed. On initial presentation, misdiagnosed patients were younger and more likely to have vomiting before pain onset, constipation, diarrhea, dysuria, and signs and s y m p t o m s of upper respiratory infections. Misdiagnosed cases were less likely to have right lower quadrant tenderness and documentation of bowel sounds, peritoneal signs, and rectal examinations. On final presentation, misdiagnosed patients were more likely to have pain duration of more than two days, temperature of more than 38.3 C, and to appear lethargic and irritable (P < .05 for all measurements). Conclusion: Clinical features of children with misdiagnosed appendicitis differ from those of children with appendicitis initially diagnosed correctly. [Rothrock SG, Skeoch G, Rush JJ, Johnson NE: Clinical features of m i s d i a g n o s e d appendicitis in children. A n n Emerg M e d January 199i;20:45-50.]
Steven G Rothrock, MD* Graydon Skeocht John J Rush, MD* N Eric Johnson, MD, MPH, FACEP* Loma Linda, California From the Department of Emergency Medicine, Loma Linda University Medical Center;* and the Loma Linda University School of Medicine,t Loma Linda, California. Received for publication March 19, 1990. Revision received August 8, 1990. Accepted for publication August 24, 1990. Presented at the Society for Academic Emergency Medicine Annual Meeting in Minneapolis, May 1990. Address for reprints: Steven G Rothrock, MD, Department of Emergency Medicine, Loma Linda University Medical Center, 11234 Anderson Street, Loma Linda, California 92350.
INTRODUCTION Diagnosing appendicitis in children can be difficult and challenging. This difficulty is underscored by the fact that misdiagnosed cases of pediatric appendicitis are associated with corresponding increased rates of perforation, abscess formation, wound infections, and deathJ -is In addition to the increased incidence of medical complications, misdiagnosis is associated with a significant risk of litigation. Prior studies have noted that misdiagnosed appendicitis is the most frequent successful malpractice claim and the fifth most expensive cause of claims against emergency physicians.t6, lz Despite the medical and legal risks, missing cases of appendicitis in children remains a common problem. 5,12 This study was performed in an attempt to identify clinical features of pediatric appendicitis that differed between cases initially misdiagnosed and those diagnosed on the first physician encounter. METHODS The study population comprised all children less than 13 years old admitted to a large university medical center between May 1, 1979, and April 30, 1989, with a discharge diagnosis of appendicitis. Patients were divided
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Annals of Emergency Medicine
20:1 January 1991
APPENDICITIS Rothrock et al
into two groups. The study group comprised all patients who had been seen by a physician within ten days of the correct diagnosis of appendicitis with the same complaints and initially misdiagnosed. The control group comprised all.patients who had been diagnosed correctly at their first physician encounter. Using the ED history and physical examination on final presentation or the admission history and physical examination if patients were transferred from another facility, 28 historical, physical examination, laboratory, and pathologic features were recorded for each patient. Whenever possible, the initial records (ie, from prior clinic or ED visit) on patients initially misdiagn0sed also were reviewed for the same 28 clinical features. Using the Student's t test and X2 analysis (with significance at P < .05), the incidence of clinical features of the control group was compared with that of the study group on initial presentation. Clinical features of the control group were also compared with those of the study group on final presentation. For patients admitted to the hospital with a misdiagnosis and later found to have appendicitis, the initial history and physical examination were used to record clinical features for the initial and final presentations. The incidence of each feature was calculated by dividing the total number of patients with documentation of the presence of a feature by the total number of patients in the group rather than by the total number of patients with documentation of the presence or absence of a particular clinical feature. Incidence of features that were dependent on the presence of a particular sign or symptom (including vomiting before or after pain onset or pain duration of less than or more than two days) was calculated by dividing the total number of patients with the dependent feature by the total number of patients with documentation of the presence or absence of that particular sign or symptom. Incidence of laboratory and radiographic features was calculated by dividing the total number of patients with a positive value by the total number of patients who had that test performed because the number of patients who had each test performed ~vas known. The misdiagnosis and location of 20:1 January 1991
physician who initially saw the patient was also recorded when available for each patient in the study group. Specialty of p h y s i c i a n involved with the initial misdiagnosis was not recorded because information regarding board certification and specialty training was unavailable for the majority of physicians. For each clinical feature in the study and control groups, the rate of documentation of the presence or absence of the feature was recorded. Using ×2 analysis (with significance at P < .05), rates Of documentation of the presence or absence of each clinical feature in the study group were compared with those in the control group on initial and final presentation.
TABLE 1. Initial diagnoses in patients with missed appendicitis Diagnosis Gastroenteritis Unspecified Upper respiratory infection Pharyngitis Otitis media Lower respiratory infection Pneumonia Bronchiolitis Sepsis Urinary tract infection Encephalitis or encephalopathy Febrile seizure Blunt abdominal trauma
No. of Patients 21 11 9 6 3 2 1 1 2 2 1 1 1
% 42 22 18
4
4 4 2 2 2
RESULTS T h e r e were 181 p a t h o l o g i c a l l y proven cases of appendicitis between May l, 1979, and April 30, 1989. Of these , 50 (28%) were classified as misdiagnoses. Records of the final presentation were available for all misdiagnosed cases. Records of the initial presentation were available for 30 of the misdiagnosed cases. Twelve of the initial misdiagnoses (24%) occurred during the same admission to the hospital in w h i c h the correct diagnoses were ultimately made. The most c o m m o n misdiagnoses were gastroenteritis and upper respiratory infections; other misdiagnoses are listed (Table 1). Initial misdiagnoses occurred at a pediatric clinic (or office) in 21 cases (42%), an ED in 15 cases (30%), and a family practice office in one case (2%). No location was specified in 13 cases (26%). On initial presentation, patients with missed appendicitis were more likely to have younger mean age (5.3 vs 7.9 years), vomiting before pain o n s e t (29% vs 8%), c o n s t i p a t i o n (13% vs 5%), dysuria (20% vs 4%), diarrhea (37% vs 10%), upper respiratory symptoms (27% vs 2%), signs of upper respiratory infections (23% vs 2%), and lethargy or irritability (40% vs 9%). On initial presentation, patients with missed appendicitis were less likely to have abdominal tenderness (50% vs 100%) and altered bowel sounds (17% vs 55%). Sex, duration of pain, complaints of fever and abdominal pain, presence of temperature of more than 38.3 C, radiographic findings, mean white blood cell count, and urinalyses also did Annals of Emergency Medicine
n o t differ s i g n i f i c a n t l y b e t w e e n groups on initial presentation (Table
2). On final p r e s e n t a t i o n , p a t i e n t s with missed appendicitis were more likely to have younger mean age (5 vs 7.9 years), pain duration of more than two days (76% vs 41%), vomiting before pain onset (33% vs 8%), constipation (18% vs 5%), diarrhea (28% vs 10%), and respiratory symptoms (28% vs 2%). Study group patients were also more likely to have temperatures of more than 38.3 C (62% vs 26%), lethargy or irritability (56% vs 9%), and upper respiratory infections (30% vs 2%). Study group patients were less likely to have maximal tenderness in the right lower quadrant on final presentation (70% vs 92%). Mean total white count, urinalyses, and abdominal radiographic findings did not differ significantly between groups. Patients with missed appendicitis were also more likely to have perforation and abdominal abscess formation on surgical and pathologic e x a m i n a t i o n (Table 3). On initial presentation, misdiagnosed patients were less likely than control group patients to have documentation of the presence or absence of abdominal pain (87% vs 98%), history of fever (67% vs 86%), constipation (37% vs 77%), and diarrhea (43% vs 88%). Physical findings less likely to be documented in misdiagnosed patients included ears, nose, and throat examinations (63% vs 98%), bowel sounds (70% vs 100%), 46/69
APPENDICITIS Rothrock et al
TABLE 2. Comparison of clinical features of initial presentation Missed Appendicitis (N = 30) No. 0t Patients % Mean age (_+ SD yr) Sex (M/M + F)
5.3 ÷ 3.6
Simple Appendicitis (N - 131) No. of Patients % (100)5
7.9 _+ 2.8
pt (100)
< .005
17/30
57 (100)
70/131
53 (100)
NS
26/30
87
25/131
91
NS
15/26
58
74/125
59
11/26
42
51/125
41
Fever
17/30
57
(67)
74/13i
56
(86)
Vomiting
24/30
80
(97)
109/131
83
(96)
7/24
29
9/109
8
17/24
71
100/109
92
15/30
50
88/131
67
Dysuria
6/30
20
(40)
5/131
4
(53)
< .01
Constipation
5/30
17
(37)
6/131
5
(77)
< .05
11/30
37
(43)
13/131
10
(88)
< .005
8/30
27
(33)
3/131
2
(41)
< .005
Symptoms Abdominal pain
(87)
(98)
Pain duration 0
2 days
> 2 days
Before pain onset After pain onset or concurrently or unknown timing Poor feeding
Diarrhea Upper and lower respiratory symptoms
(70)
NS NS NS NS < .01 < .01 (85)
NS
Signs Temperature > 38.3 C
7/30
23
(90)
34/131
26
(99)
NS
Irritability or lethargy
12/30
40
(37)
12/t31
9
(62)
< .005
Ears, nose, and throat infection
7/30
23
(63)
2/131
2
(98)
< .005
Altered bowel sounds
5/30
17
(70)
72/131
55
(100)
< .005
(100)
Maximal tenderness
(100)
43
120/131
92
2/30
7
11/131
8
15/30
50
0
Right lower quadrant*
13/30
Other than right lower quadrant Nontender Peritoneal signs
0/30
0
(10)
65/131
50
(96)
< .005
Rectal tenderness
0/30
0
(13)
18/131
14
(50)
NS
< .005
13,400 +_ 5,300
(67)
16,900 + 6,700
(98)
NS
NS < .005
Laboratory Features Total WBCs UrinalYsis WBCs or RBCs/hpf > 5
(77) 3/23
8
(84) 8/11.0
7
(33)
Radiographs
NS (48)
Normal
7/10
70
30/63
48
NS
Abnormal
NS
3/10
30
33/63
52
Suggestiveof appendicitis
1/10
10
14/63
22
Not specific for appendicitis
2/10
20
19/63
30
63
29/131
22
Palholooy Perforation Retrocecal or abnormal location
(100) 19/30
(100) < .005
2/30
7
7/13i
5
NS
Abdominal abscess
8/30
27
5/131
4
< .005
Mortality
2/30
7
NS
*Included were patients with diffuse or bilateral lower quadrant tenderness as long as right lower quadrant tenderness was documented to be at least as maximal as tenderness at other sites. tp value is derived from Student's t test for mean age and WBC count; all ether P values are derived from X 2 analysis. :~Numbers in parentheses indicate rate of documentation of presence or absence of clinical featul-e.
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peritoneal signs (10% vs 96%), and rectal examinations (13% vs 50%)(P < .01 for all comparisons). On final presentation, misdiagnosed patients were less likely to have d o c u m e n t a t i o n of peritoneal signs (74% vs 96%) and more likely to have abdominal radiography performed (74% vs 48%). Rates of documentation of all other clinical features were not significantly different between study and control groups on final presentation (P < .01 for all comparisons).
Annals of Emergency Medicine
DISCUSSION The diagnosis of appendicitis in children is generally considered more difficult than in adults: is Children are more likely to have symptoms for a longer period of time before a correct diagnosis is made than are adults and are more likely to suffer from the complications of perforation, abscess formation, peritonitis, and death. 19-27 Prior studies have noted that the detection of appendicitis in Children is often delayed due to misdiagnosis by physicians.~-]5 Reported rates of misdiagnosis vary from 7.5% to 12% for children less than 15 years old and are as high as 57% for children less than six years old. 5,6,9 Our misdiagnosis rate of 28% lin all patients less than 13 years old) is consistent with these prior studies. This misdiagnosis rate, however, may be misleading because the study facility is a tertiary-care hospital w i t h pediatric surgical specialists. Thus, more complicated cases (and possibly more pat i e n t s w h o are i n i t i a l l y m i s d i a g nosed) might be transferred to this facility. In addition, this misdiagnosis rate does not take into consideration patients who were misdiagnosed at the study facility and later diagnosed at another facility because of the difficulty in identifying this class of patients. Although a significant physician-caused delay due to misdiagnosis has been well documented in the l i t e r a t u r e , no studies have attempted to determine whether differing clinical features contribute to misdiagnosis, Our study compared incidences of historical, physical, laboratory, and pathologic features of children with misdiagnosed appendicitis with those of children with appendicitis diagnosed correctly at the first physician encounter to det e r m i n e w h e t h e r d i f f e r i n g clini20:1 January 1991
APPENDICITIS Rothrock et al
cal features were associated w i t h misdiagnosis. In our study, misdiagnoses did not differ significantly from prior reports of missed cases of appendicitis. As in prior studies, we found gastroenteritis to be the most common misdiagnosis.S,7,9,12 The reasons for this are apparent as b o t h disease processes cause abdominal pain, vomiting, and varying degrees of tempera~ ture elevation. However, upper respiratory infections were also found to be a c o m m o n misdiagnosis in our study. The reasons for this misdiagnosis are less Clear because the constellation of signs and symptoms with each disease process do not overlap. Of the other misdiagnoses (Table 1), urinary tract infections, meningitis, encephalitis~ febrile seizures, sepsis, and p n e u m o n i a have been reported as erroneous diagnoses in p a t i e n t s with appendicitis.3,s,7,9-12, 28 However, no prior cases of appendicitis misdiagnosed as blunt abdominal trauma could be found in the literature. Other reported misdiagnoses not found in our study include right hip septic arthritis, testicular torsion, bowel obstruction, inflammatory bowel disease, dehydration, and cholecystitis.5,7,9,m,29 Primary-care facilities (pediatric clinics and EDs) were responsible for the majority of misdiagnosed cases of appendicitis in our study. No comment can be made concerning the training or board certification of physicians involved with misdiagnosis because information regarding specialty training and board certification was unavailable for the majority of physicians. In addition, during the first few years of the study period, board-certified emergency physicians were rare because this specialty was formed during the late 1970s. The preponderance of primary-care facilities (or physicians) involved with the m i s d i a g n o s i s of p e d i a t r i c appendicitis may be more of a reflection of the large numbers of patients with abdominal complaints seen at these locations than of any i n a d e q u a t e training or experience of physicians working at these locations. It should also be noted that the specialties of general surgery, urology, and gynecology were involved as c o n s u l t a n t s with cases initially misdiagnosed. Regardless of location or specialty, physicians involved with the care of children should be made aware of the 20:1 January 1991
TABLE 3. Comparison of clinical features
on
Missed Appendicitis (N = 30) No, of Patients % 5 ± 3.2
Mean age (± SD yr)
final presentation Simple Appendicitis (N = 131) No. of Patients %
(100);
7.9 + 2.6
pt (100)
28/50
56
(100)
70/131
41/50
82
(96)
125/131
95
0 - 2 days
10/41
24
74/125
59
< .005
> 2 days
31/41
76
51/125
41
< .005
Sex (M/M + F)
53 (100)
< .005 NS
Symptoms Abdominal pain
(98)
< .01
Pain duration
Fever
37/50
74
(96)
74/131
56
(86)
Vomiting
42/50
84
(98)
109/131
83
(96)
< .05
Before pain onset
14/42
33
9/109
8
< .005
After pain onset or concurrently or unknown timing
28/42
67
100/109
92
< .005
NS
35/50
70
(80)
88/131
67
(85)
Dysuria
3/50
6
(46)
5/131
4
(53)
NS
Constipation
9/50
18
(78)
6/131
5
(77)
< .01
Diarrhea
14/50
28
(88)
13/131
10
(88)
< .005
Upper and lower respiratory symptoms
14/50
28
(52)
3/131
2
(41)
< .005
Signs Temperature > 38.3 C
31/50
62
(98)
34/131
26
(99)
< .005
Irritability or lethargy
28/50
56
(70)
12/131
9
(62)
< .005
Ears, nose, and throat infection
15/50
30
(94)
2/131
2
(98)
< .005
Altered bowel sounds
30/50
60
(100)
72/131
55
(100)
NS
35/50
70
120/131
92
Other than right lower quadrant
7/50
14
11/131
8
Nontender
8/50
16
0
Peritoneal signs
18/50
36
(74)
65/131
50
(96)
NS
Rectal tenderness
12/50
24
(46)
18/131
14
(50)
NS
16,900 ± 6,700 (100)
NS
Poor feeding
(100)
Maximal tenderness Right lower quadrant*
NS
(100) < .005 NS < .005
Laboratory Features Total WBCs
16,700 ± 6,600 (100) (88)
Urinalysis 6/44
WBCs or RBOs/bpf > 5
14
(84) 8/110
7
(74)
Radiographs
NS (48)
Normal
15/37
40
30/63
48
NS
Abnormal
22/37
60
33/63
52
NS
9/37
24
14/63
22
13/3"7
35
19/63
36
Suggestive of appendicitis Not specific for appendicitis
(100)
NS (100)
Pathology Perforation Retrocecal or abnormal location
26/50
52
29/131
22
4/50
8
7/131
5
NS
Abdominal abscess
10/50
20
5/131
4
< .005
2/50
4
Mortality
0
< ,005
NS
*Included were patienls with diffuse or bilateral lower quadrant tenderness as long as right lower quadrant tenderness was documented to be at least as maximal as tenderness at other sites. tp value is derived from Studenl's t test for mean age and WBC counl; all other P values are derived from x 2 analysis• ;Numbers in parentheses indicate rate of documentation of presence or absence of clinical feature•
Annals of Emergency Medicine
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APPENDICITIS Rothrock et al
high incidence of missed appendicitis in younger age groups. Several potential reasons for misdiagnoses exist in children with appendicitis. Younger children are less able to verbalize their complaints to physicians. Because of difficulties with communication, interpretation of physical examination findings also becomes more difficult. This difficulty may in part explain why almost half (43%) of misdiagnosed patients in our study had maximal tenderness including the right lower quadrant on initial examination and were still thought to have a nonsurgical abdomen. It appears that in these patients, p h y s i c i a n s either disregarded this finding or thought that it was insignificant, whereas it was an important clue to the early diagnosis of appendicitisl Several a u t h o r s stress that the presence of right lower quadrant tenderness is probably the most sensitive physical finding in early appendicitis. 13,3°-33 At the very least, patients with maximum tenderness in the right lower quadrant who are suspected of having a benign intraabdominal process should be reassessed within a short time period with consideration of hospital admission and surgical consultation if the patient's clinical picture becomes more suspicious. An alternative in equivocal cases, if readily available, is ultrasound, which has a nearly 90% sensitivity in diagnosing appendicitis.34, 35 The presence of atypical signs and symptoms may also have dissuaded physicians from considering the diagnosis of appendicitis in several cases. Alterations of bowel habits, including constipation and diarrhea, were more c o m m o n in the study group than i,n the c o n t r o l group. Prior studies have noted a 9% to 33% incidence of constipation and a 10% to 33% incidence of diarrhea in children w i t h a p p e n d i c i t i s . g , 6 j , lo, is, 2o,~1,3o Although diarrhea secondary to gastroenteritis or to constipation can give rise to abdominal discomfort, neither typically causes localized right lower quadrant tenderness, peritoneal signs, or rectal tenderness. If any of these physical findings are present, c o n s i d e r a t i o n should be given to a surgical cause for abdo.minal pain: In addition to altered bowel habits, patients with missed appendicitis 72/49
were more likely to have vomiting that preceded the onset of abdominal pain than were patients with simple appendicitis. It is widely taught that the large majority of patients with appendicitis have onset of vomiting after their pain begins.18,36, 3z One possible explanation for the discrepancy between our results and this classic teaching is that young children are less able to verbalize their feelings. Parents may have first noticed that there was a problem only after their child vomited. Thus, pat i e n t s m a y have had pain before vomiting that was not noticed by their parents. Respiratory symptoms were also noted to be more c o m m o n in the s t u d y group than in the c o n t r o l group. The association of respiratory infections and appendicitis has been noted by prior authors who have reported a higher incidence of both diseases during the winter and spring and have postulated that similar etiologic agents may be involved.19, 38,39 Reasons for this association are unclear. However, upper and lower respiratory infections often coexist in patients with appendicitis.7,1O-l~, ~8, 38,39 Although it is widely taught that basilar pneumonias can mimic appendicitis, physicians should not let concurrent upper or lower respiratory infections stop them from considering the diagnosis of appendicitis in children with other suggestive clinical features. 18,36,37,4° Dysuria was another clinical feature that occurred with a higher frequency in the study group. Dysuria reportedly occurs in 7% to 15% of patients with appendicitis, whereas an abnormal urinalysis (more than 5 WBCs or RBCs per high-power field) is present in as many as 30% of patients, lS,2O,41 Because of its proximity to the ureter, an inflamed appendix lying in the pelvis can cause irritation and dysuria in addition to abnormal urinalyses. Although patients in the study group were more likely to have dysuria, the incidence of positive urinalyses was similar in the two groups. Another factor other than atypical clinical features in misdiagnosed cases was poor d o c u m e n t a t i o n of physical findings. Although the majority of patients with missed appendicitis had vomiting and abdominal pain and all had one of these sympt o m s , d o c u m e n t a t i o n of b o w e l Annals of Emergency Medicine
sounds, peritoneal signs, and rectal examinations was poor. No explanation can be given for the lack of docu m e n t a t i o n of bowel sounds and peritoneal signs in patients with vomiting and abdominal pain. Also disturbing is that CBCs (obtained in 67% of cases), urinalyses (obtained in 77% of cases), and radiographs (obtained in 33% of cases) were performed (or at least documented) more often than rectal examinations (13%) on initial presentation. Normal radiographs and WBC counts may have falsely reassured physicians that patients had benign causes for their a b d o m i n a l complaints. Even though some physicians believe that they gain little information from performing rectal examinations ( e s p e c i a l l y in a frightened, apprehensive child), they should be aware that 50% to 80% of children w i t h a p p e n d i c i t i s (even those less than 6 years old) have lo~ calized rectal tenderness, and as many as 25% have palpable masses rectally.l,21, 26 Physicians may diagnose a case of appendicitis that they might have otherwise missed by performing a rectal examination. Morbidity from missed cases of appendicitis was significant. On final presentation, patients appeared to be more ill than in the control group. They were more likely to be irritable, lethargic, and febrile with temperature of more than 38.3 C. Duration of symptoms also was longer than in control patients. Complications of perforation and intra-abdominal abscess formation were more prevalent in the study group. The only two deaths occurred in the study group, although mortality rates were not statistically different between groups. Atypical clinical features seen on initial presentation also were noted on final presentation, including dysuria, constipation, diarrhea, respiratory symptoms, signs of respiratory infections, irritability, lethargy, and less-frequent right lower quadrant tenderness. It is possible with the increased incidence of these features on initial and final presentation compared with the control group that patients with misdiagnosed appendicitis are not patients early in the course of their disease who have not'yet manifested all of the typical clinical features of appendicitis; they appear to be an entirely different population with dif20:1 January 1991
APPENDICITIS Rothrock et al
feting clinical features. A large number of children with appendicitis may be misdiagnosed because of their atypical clinical features. There are several limitations that should be acknowledged in reviewing the results of this study. Selection of patients for study may have been flawed. The study hospital is a tertiary-care facility with pediatric surgical specialists. Thus, there is a possibility that more complicated cases that may have been misdiagnosed at outlying hospitals without pediatric surgical specialists were transferred to this facility, resulting in a higher rate of atypical cases and misdiagnosis. Due to the retrospective nature of data collection, it was also not possible to determine whether signs and s y m p t o m s not recorded were present. The incidence of each feature was calculated by dividing the total number of patients with a particular feature present by the total number of patients in the group rather than by the total number with documentation of the presence or absence of this feature. This method was chosen to determine incidence because the authors believed that features not documented (in either a positive or negative manner) were likely to be absent or less significant to the examining physician or patient. This technique might potentially lower the incidence of certain clinical features because it essentially categorizes features that were not documented in either a positive or negative fashion as absent. However, the alternate method of calculating the incidence of clinical features by dividing the number of patients with a feature documented as present by the total number with that feature documented as present or absent is also flawed because it assumes that the rates of documentation of features will be similar for features that are present and absent. Regardless of the method used, calculating the incidence of each clinical feature is dependent on chart documentation that is nonstandardized and incomplete. CONCLUSION A retrospective study was performed to compare clinical features
20:1 January 1991
of patients with misdiagnosed appendicitis with those of patients diagnosed correctly at the first physician encounter. Patients with misdiagnosed appendicitis were found to be younger and have more atypical symptoms on initial and final presentation, including v o m i t i n g before pain onset, dysuria, constipation, diarrhea, and upper respiratory symptoms. They were also more likely to have physical findings of upper respiratory i n f e c t i o n s , lethargy, irritability, normal bowel sounds, and non-right lower quadrant tenderness. Documentation of abdominal findings and rectal examination was less common in patients with missed appendicitis on their first presentation to a physician. Physicians should be aware that atypical signs and symptoms are often associated with missed cases of appendicitis. Physicians caring for children should be alert to the atypical clinical features and many pitfalls to be avoided in diagnosing appendicitis in younger age groups. REFERENCES
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