IN BRIEF
Noninfectious Subcutaneous Emphysema of the Upper Extremity Jacob A. Mack, BS, Shoshana L. Woo, MD, Steven C. Haase, MD
ETIOLOGY A commonly reported cause of noninfectious upper extremity subcutaneous emphysema is the injection of air or inert gas (Table 1). Such cases have involved compressed air tools, a football inflation pump, scuba diving equipment, an air rifle, a mishap during blood donation, and factitious manipulations related to Münchausen syndrome. A small hand or wrist laceration or puncture wound can also lead to crepitus by serving as a one-way valve for airflow into the soft tissues. The mechanism was first proposed by Kemp2 and later demonstrated in cadavers by Brummelkamp.3 In the presence of a web From the University of Michigan Medical School; and the Section of Plastic Surgery, Department of Surgery, University of Michigan Health System, Ann Arbor, MI.
space puncture wound, for example, digital abduction and adduction produce negative pressure, drawing air into the subcutaneous space; the air is then trapped as the wound collapses. Repetitive motion can thus lead to progressive subcutaneous air accumulation. This mechanism has been corroborated by others,4e6 and such injuries have been referred to as “sucking wounds” of the limbs.7 Another cause of noninfectious subcutaneous emphysema is the accidental or deliberate injection of chemical substances. Reported cases have involved the use of magnesium alloy powder by machinists, hydrogen peroxide during wound cleansing, hexafluoroethane (Freon) used to manufacture athletic shoes, natural gas from a ruptured gas line, and nhexane spot remover fluid in an attempted suicide. Pulmonary events related to pneumomediastinum, pneumothorax, and ventilator use have also been associated with upper extremity subcutaneous emphysema. Surgical causes have been reported as well in the form of molar extraction, joint mobilization exercises after elbow arthroscopy, and the malfunction of a suction drain after wrist ganglion cyst removal. CLINICAL PRESENTATION Generally, patients with noninfectious subcutaneous emphysema are devoid of systemic symptoms (Table 2). Crepitus develops within minutes to hours after injury and pain is mild to moderate. In contrast, patients with necrotizing fasciitis are febrile and often appear toxic, and crepitus appears at least 12 hours after injury. Disproportionate pain is the most sensitive sign and often the first one of necrotizing fasciitis (Table 2).
Received for publication January 28, 2015; accepted in revised form March 5, 2015. No benefits in any form have been received or will be received related directly or indirectly to the subject of this article. Corresponding author: Steven C. Haase, MD, Section of Plastic Surgery, Department of Surgery, University of Michigan Health System, 2130 Taubman Center, 1500 E Medical Center Drive, Ann Arbor, MI 48109; e-mail: [email protected]. 0363-5023/15/4006-0031$36.00/0 http://dx.doi.org/10.1016/j.jhsa.2015.03.012
DIAGNOSTIC TESTS Radiological studies may be helpful for the diagnosis, provided that they do not delay treatment. Plain radiographs can be rapidly obtained. In noninfectious cases, air is seen to respect the tissue planes (Fig. 1). In gas gangrene, air can be seen to
Ó 2015 ASSH
r
Published by Elsevier, Inc. All rights reserved.
r
1233
In Brief
C
emphysema in the upper extremity can be alarming for necrotizing fasciitis or gas gangrene, a rapidly progressing infection of the subcutaneous tissue and deep fascia with high morbidity and mortality.1 However, noninfectious etiologies exist and must be promptly recognized to avoid unnecessary surgery. The distinction is critical: Whereas the misdiagnosis of necrotizing fasciitis in noninfectious cases can lead to unnecessary surgery, the neglect of true necrotizing fasciitis can result in limb amputation or death. This review describes the various etiologies, workup and diagnosis, and general guidelines for management of noninfectious subcutaneous emphysema of the upper extremity. A total of 67 cases have been reported in the English scientific literature (Table 1), a minority of which were reported in hand surgery journals. REPITUS CAUSED BY SUBCUTANEOUS
1234
NONINFECTIOUS SUBCUTANEOUS EMPHYSEMA
TABLE 1.
Reported Etiologies of Noninfectious Subcutaneous Emphysema in the Upper Extremity
Etiology
n (%)
Reference
Air or inert gas injection
25 (37)
4, 10e23
Laceration or puncture
25 (37)
3e7, 9, 24e30
Chemical injection
10 (15)
4, 31e35
Pulmonary event Surgical complication Total
4 (6)
4, 36
3 (5)
4, 37
67
TABLE 2. Criteria to Differentiate Subcutaneous Emphysema From Necrotizing Fasciitis and Noninfectious Etiologies Criterion
In Brief
Necrotizing Fasciitis
Noninfectious Etiologies
Reference
Clinical signs
Toxemia, fever, chills, hypotension, tachycardia, swelling, erythema, disproportionately severe pain, tense edema, bullae, purplish skin discoloration, crepitus, sensory and motor deficits, altered mental status
No signs of sepsis or toxemia. No signs of vascular, sensory, or motor deficits. Crepitus, tenderness, swelling, and erythema may be present.
1, 4e6, 38
Timing
12e18 h until onset of clinically significant crepitus
6 h to produce clinically significant crepitus
6, 24
Leukocytes
> 15.4 109/L
Within normal limits
38
Serum sodium
< 135 mmol/L
Within normal limits
38
Blood urea nitrogen
> 15 mg/dL
Within normal limits
39
Magnetic resonance imaging
Fascial inflammation appears as low T1/high T2 signals; necrosis detected by absence of gadolinium enhancement
e
8
X-ray
Gas within muscle bundles, with edema of overlying skin and superficial soft tissues
Gas limited to loose soft tissues external to muscles and deep fascia; fat shadows and skin-fat differentiation are well preserved
24
Computed tomography scan
Asymmetrical fascial thickening with fat stranding and presence of gas
Tissue biopsy
Cultures and Gram stains are positive for polymicrobial infection
Cultures, Gram stains, and biopsies are negative for necrotizing infection
Laboratory Risk Indicator for Necrotizing Fasciitis score (see Table 3)
6
13.5
0
11e13.5
1
< 11
2
135
0
< 135
2
1.6
0
> 1.6
2
180
0
> 180
1
Hemoglobin, g/dL
Sodium, mmol/L Creatinine, mg/dL Glucose, mg/dL Total score
6
Not necrotizing soft tissue infection
Noninfectious Subcutaneous Emphysema of the Upper Extremity Jacob A. Mack, BS, Shoshana L. Woo, MD, Steven C. Haase, MD
ETIOLOGY A commonly reported cause of noninfectious upper extremity subcutaneous emphysema is the injection of air or inert gas (Table 1). Such cases have involved compressed air tools, a football inflation pump, scuba diving equipment, an air rifle, a mishap during blood donation, and factitious manipulations related to Münchausen syndrome. A small hand or wrist laceration or puncture wound can also lead to crepitus by serving as a one-way valve for airflow into the soft tissues. The mechanism was first proposed by Kemp2 and later demonstrated in cadavers by Brummelkamp.3 In the presence of a web From the University of Michigan Medical School; and the Section of Plastic Surgery, Department of Surgery, University of Michigan Health System, Ann Arbor, MI.
space puncture wound, for example, digital abduction and adduction produce negative pressure, drawing air into the subcutaneous space; the air is then trapped as the wound collapses. Repetitive motion can thus lead to progressive subcutaneous air accumulation. This mechanism has been corroborated by others,4e6 and such injuries have been referred to as “sucking wounds” of the limbs.7 Another cause of noninfectious subcutaneous emphysema is the accidental or deliberate injection of chemical substances. Reported cases have involved the use of magnesium alloy powder by machinists, hydrogen peroxide during wound cleansing, hexafluoroethane (Freon) used to manufacture athletic shoes, natural gas from a ruptured gas line, and nhexane spot remover fluid in an attempted suicide. Pulmonary events related to pneumomediastinum, pneumothorax, and ventilator use have also been associated with upper extremity subcutaneous emphysema. Surgical causes have been reported as well in the form of molar extraction, joint mobilization exercises after elbow arthroscopy, and the malfunction of a suction drain after wrist ganglion cyst removal. CLINICAL PRESENTATION Generally, patients with noninfectious subcutaneous emphysema are devoid of systemic symptoms (Table 2). Crepitus develops within minutes to hours after injury and pain is mild to moderate. In contrast, patients with necrotizing fasciitis are febrile and often appear toxic, and crepitus appears at least 12 hours after injury. Disproportionate pain is the most sensitive sign and often the first one of necrotizing fasciitis (Table 2).
Received for publication January 28, 2015; accepted in revised form March 5, 2015. No benefits in any form have been received or will be received related directly or indirectly to the subject of this article. Corresponding author: Steven C. Haase, MD, Section of Plastic Surgery, Department of Surgery, University of Michigan Health System, 2130 Taubman Center, 1500 E Medical Center Drive, Ann Arbor, MI 48109; e-mail: [email protected]. 0363-5023/15/4006-0031$36.00/0 http://dx.doi.org/10.1016/j.jhsa.2015.03.012
DIAGNOSTIC TESTS Radiological studies may be helpful for the diagnosis, provided that they do not delay treatment. Plain radiographs can be rapidly obtained. In noninfectious cases, air is seen to respect the tissue planes (Fig. 1). In gas gangrene, air can be seen to
Ó 2015 ASSH
r
Published by Elsevier, Inc. All rights reserved.
r
1233
In Brief
C
emphysema in the upper extremity can be alarming for necrotizing fasciitis or gas gangrene, a rapidly progressing infection of the subcutaneous tissue and deep fascia with high morbidity and mortality.1 However, noninfectious etiologies exist and must be promptly recognized to avoid unnecessary surgery. The distinction is critical: Whereas the misdiagnosis of necrotizing fasciitis in noninfectious cases can lead to unnecessary surgery, the neglect of true necrotizing fasciitis can result in limb amputation or death. This review describes the various etiologies, workup and diagnosis, and general guidelines for management of noninfectious subcutaneous emphysema of the upper extremity. A total of 67 cases have been reported in the English scientific literature (Table 1), a minority of which were reported in hand surgery journals. REPITUS CAUSED BY SUBCUTANEOUS
1234
NONINFECTIOUS SUBCUTANEOUS EMPHYSEMA
TABLE 1.
Reported Etiologies of Noninfectious Subcutaneous Emphysema in the Upper Extremity
Etiology
n (%)
Reference
Air or inert gas injection
25 (37)
4, 10e23
Laceration or puncture
25 (37)
3e7, 9, 24e30
Chemical injection
10 (15)
4, 31e35
Pulmonary event Surgical complication Total
4 (6)
4, 36
3 (5)
4, 37
67
TABLE 2. Criteria to Differentiate Subcutaneous Emphysema From Necrotizing Fasciitis and Noninfectious Etiologies Criterion
In Brief
Necrotizing Fasciitis
Noninfectious Etiologies
Reference
Clinical signs
Toxemia, fever, chills, hypotension, tachycardia, swelling, erythema, disproportionately severe pain, tense edema, bullae, purplish skin discoloration, crepitus, sensory and motor deficits, altered mental status
No signs of sepsis or toxemia. No signs of vascular, sensory, or motor deficits. Crepitus, tenderness, swelling, and erythema may be present.
1, 4e6, 38
Timing
12e18 h until onset of clinically significant crepitus
6 h to produce clinically significant crepitus
6, 24
Leukocytes
> 15.4 109/L
Within normal limits
38
Serum sodium
< 135 mmol/L
Within normal limits
38
Blood urea nitrogen
> 15 mg/dL
Within normal limits
39
Magnetic resonance imaging
Fascial inflammation appears as low T1/high T2 signals; necrosis detected by absence of gadolinium enhancement
e
8
X-ray
Gas within muscle bundles, with edema of overlying skin and superficial soft tissues
Gas limited to loose soft tissues external to muscles and deep fascia; fat shadows and skin-fat differentiation are well preserved
24
Computed tomography scan
Asymmetrical fascial thickening with fat stranding and presence of gas
Tissue biopsy
Cultures and Gram stains are positive for polymicrobial infection
Cultures, Gram stains, and biopsies are negative for necrotizing infection
Laboratory Risk Indicator for Necrotizing Fasciitis score (see Table 3)
6
13.5
0
11e13.5
1
< 11
2
135
0
< 135
2
1.6
0
> 1.6
2
180
0
> 180
1
Hemoglobin, g/dL
Sodium, mmol/L Creatinine, mg/dL Glucose, mg/dL Total score
6
Not necrotizing soft tissue infection
