Short Communication
Which clinical signs predict hypoxaemia in young Senegalese children with acute lower respiratory tract disease? G. Wandeler1,2,3, J. Y. Pauchard4, E. Zangger3,4, H. Diawara3, M. Gehri3,4 1
Department of Infectious Diseases, University Hospital, Bern, Switzerland, 2Institute of Social and Preventive Medicine, University of Bern, Switzerland, 3Ndioum District Hospital, Senegal, 4Hoˆpital de l’Enfance de Lausanne, Switzerland Background: Acute lower respiratory tract diseases are an important cause of mortality in children in resource-limited settings. In the absence of pulse oximetry, clinicians rely on clinical signs to detect hypoxaemia. Objective: To assess the diagnostic value of clinical signs of hypoxaemia in children aged 2 months to 5 years with acute lower respiratory tract disease. Methods: Seventy children with a history of cough and signs of respiratory distress were enrolled. Three experienced physicians recorded clinical signs and oxygen saturation by pulse oximetry. Hypoxaemia was defined as oxygen saturation ,90%. Clinical predictors of hypoxaemia were evaluated using adjusted diagnostic odds ratios (aDOR). Results: There was a 43% prevalence of hypoxaemia. An initial visual impression of poor general status [aDOR 20.0, 95% CI 3.8–106], severe chest-indrawing (aDOR 9.8, 95% CI 1.5–65), audible grunting (aDOR 6.9, 95% CI 1.4–25) and cyanosis (aDOR 26.5, 95% CI 1.1–677) were significant predictors of hypoxaemia. Conclusion: In children under 5 years of age, several simple clinical signs are reliable predictors of hypoxaemia. These should be included in diagnostic guidelines.
Keywords: Under-5 children, Acute lower respiratory disease, Hypoxaemia, Pulse oximetry
Introduction Acute respiratory infections (ARI) are one of the most important causes of mortality in children aged 2 months to 5 years in resource-limited settings.1 In the severest cases, these children develop hypoxaemia, which is predictive of death.2 To date, no consensus has been reached on the importance of specific clinical predictors of hypoxaemia in children with acute respiratory disease, despite the publication of several reports on the subject.2–7 In their systematic review and meta-analysis of the accuracy of symptoms and signs in predicting hypoxaemia in children, Zhang et al. found only 11 studies and there was high Heterogeneity in the results across the studies.8 As the administration of oxygen is of primary importance in these situations, hypoxaemia has to be detected rapidly. Measurement oxygen saturation with a portable pulse oximeter is a reliable method of diagnosing hypoxaemia in children; however, it is rarely available in resource-limited Correspondence to: M Gehri, Hoˆ pital de l’Enfance de Lausanne, De´partement Me´dico-chirurgical de Pe´diatrie, Avenue de Monte´tan 1007, Lausanne, Switzerland. Email: [email protected]
ß W. S. Maney & Son Ltd 2015 DOI 10.1179/2046905514Y.0000000153
settings.9 Therefore, it is essential to provide healthcare workers with the means to rely on clinical signs of hypoxaemia so that these patients can be referred to health care facilities with access to oxygen therapy.10 This study aimed to assess the diagnostic value of different clinical signs of hypoxaemia in children with acute lower respiratory distress.
Subjects and Methods Children between the ages of 2 months and 5 years with acute lower respiratory tract distress caused by respiratory infections or wheezing diseases (asthma, bronchitis) who presented to the paediatric emergency ward of Ndioum Hospital in rural Senegal were enrolled prospectively between June 2002 and January 2003. All the children were evaluated on admission for general signs as well as the symptoms and signs of respiratory distress by one of three senior physicians. Hypoxaemia was defined as oxygen saturation (SaO2) ,90%. SaO2 was measured using a Nellcor NPB-40 portable pulse oximeter (Ndioum Hospital is 12 m above sea level). Several clinical signs and parameters were assessed during physical examination (Table 1).
Paediatrics and International Child Health
2015
VOL.
35
NO.
1
65
Wandeler et al.
Clinical signs of hypoxaemia
Table 1 Description of clinical signs and characteristics Clinical signs and parameters
Remarks
General signs Poor general status
First visual impression: looks bad/looks good, severe lethargy or reduced level of consciousness
Inability to cry
Test of giving something to drink during examination
Inability to drink Visible and/or audible respiratory signs
Nasal flaring Central cyanosis Head-nodding
Head-nodding is defined as head movements that are synchronous with each breath and are due to contractions of accessory muscles of respiration See-saw breathing, visible at first sight Audible without stethoscope Audible at mouth and/or with stethoscope
Measurements
Severe chest-indrawing Grunting Wheezing Temperature (rectal)
Abnormal if >38uC
Respiratory rate
If .70/min, pathological at all ages, counted over 1 min, child calm, nose not blocked ,70%, severe acute malnutrition
Weight-for-height ratio
Statistical analysis
The study protocol was approved by the ethics committee of the Faculty of Medicine, Lausanne University, Switzerland (Comite´ d’Ethique de la Faculte´ de Me´decine de Lausanne, No. 158/01) and by the medical chief of the De´partement of Podor, Senegal.
Statistical analyses were performed using Epi-Info, version 2012. The patients were classified into two groups according to their oxygen saturation level – non-hypoxaemic vs. hypoxaemic. The proportions of patients with each clinical sign or symptom were evaluated. Sensitivity, specificity, positive predictive value, negative predictive value and the diagnostic odds ratio (DOR), a single indicator of diagnostic performance,11 were used as measures of diagnostic value of each clinical sign. The analyses were performed separately for each clinical sign or symptom, and using a multivariable logistic regression model adjusted for age and all clinical signs and symptoms with a statistically significant DOR (P , 0.05) in univariate analysis.
Results Seventy children aged 2 months to 5 years were included in the study (33 girls, 37 boys). The median age was 17.4 months. Five children (7%) were severely malnourished (weight for height ,70%) and seven (10%), all hypoxaemic, died shortly after admission. The majority of children were diagnosed with infectious respiratory diseases (n 5 44, 63%), including pneumonia and bronchiolitis, and the rest (n 5 26, 37%) with wheezing diseases such as
Table 2 Distribution of type of acute lower respiratory tract disease (ALRD) and related prevalence of hypoxaemia (SaO2 ,90%) Type of ALRD
No. of patients (%)
Hypoxaemic patients* n (%)
Pneumonia Bronchiolitis Bronchitis with wheeze Any others ALRD Total
34 10 14 12 70
20 5 3 2 30
(49) (14) (20) (17) (100)
* SaO2 ,90%.
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(59) (50) (21) (17) (43)
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Clinical signs of hypoxaemia
Table 3 Clinical predictors of hypoxaemia in 70 children (SaO2 ,90%) Prevalence n (%) General clinical signs Poor general status 40 (58) Inability to cry 28 (40) Inability to drink 54 (77) Temperature .38Cu 29 (41) Severe malnutrition 5 (7) (W/H ,70%) Respiratory distress signs Nasal flaring 51 (72) Cyanosis 11 (15) Head-nodding 23 (32) Severe 48 (68) chest-indrawing Grunting 27 (38) Wheezing 41 (59) Tachypnoea 11 (16) (RR .70/min)
Sensitivity, % (95% CI)
Specificity, % (95% CI)
PPV, % (95% CI)
NPV, % (95% CI)
DOR, % (95% CI)
aDOR{ % (95% CI)
90 63 83 53 7
(79–100) (46–81) (70–97) (35–71) (0–16)
68 78 28 68 93
(53–82) (65–90) (14–41) (53–82) (84–100)
68 68 46 55 40
(53–82) (51–85) (33–60) (37–73) (3–83)
90 74 69 66 57
(79–100) (61–87) (46–91) (51–80) (45–69)
18 5.9 1.8 2.3 0.8
(4.8–73)* (2–16)* (0.5–6.2) (0.8–6.2) (0.1–5.6)
20 (3.8–106)* 1.2 (0.3–5)
93 33 43 93
(84–100) (16–50) (26–61) (84–100)
43 98 75 50
(27–58) (93–100) (62–88) (35–65)
55 91 57 58
(41–69) (74–100) (36–77) (44–72)
89 66 64 91
(76–100) (54–78) (50–78) (79–100)
10 19 2.2 14
(2.1–49)* (2.3–113)* (0.8–6.3)* (2.9–66)*
4.5 26 0.5 9.9
67 (50–84) 66 (48–83) 27 (11–42)
83 (71–94) 45 (30–60) 93 (84–100)
74 (58–91) 46 (31–62) 73 (46–99)
77 (64–89) 64 (47–82) 63 (50–75)
9.4 (3–28)* 1.5 (0.5–4) 4.5 (1.1–18)*
(0.4–46) (1–677)* (0.1–2.8) (1.4–65)*
6 (1.4–25)* 3.2 (0.4–27)
PPV, positive predictive value; NPV, negative predictive value; DOR, diagnostic odds ratio; aDOR, adjusted diagnostic odds ratio; CI, confidence interval; W/H, weight/height ratio; RR, respiratory rate; * P , 0.05; { adjusted with multiple logistic regression for age and other variables significant on univariate analysis.
asthma (Table 2). Overall, 30 children (43%) were hypoxaemic. Of all the patients, 58% were of poor general status (PGS), 41% were febrile, 77% were unable to drink and 40% unable to cry during examination (Table 3). Nasal-flaring (72%), severe chest-indrawing (68%) and wheezing (59%) were the signs of respiratory distress most frequently observed. In univariable analyses, PGS, inability to cry, cyanosis, headnodding, severe chest-indrawing and grunting predicted hypoxaemia. However, in adjusted analyses, only PGS (aDOR 20, 95% CI 3.8–106), severe chestindrawing (aDOR 9.9, 1.5–65), cyanosis (aDOR 26, 1.1–677) and grunting (aDOR 6, 1.4–25) were significant predictors of hypoxaemia (Table 3).
Discussion In this study of young children in rural Senegal with respiratory distress, four clinical signs were strongly predictive of hypoxaemia: PGS, grunting, severe chest indrawing and cyanosis. The results confirm the findings of previous studies demonstrating the importance of grunting in the evaluation of a child with acute respiratory distress.12,13 Severe chest-indrawing, which has been less emphasised in clinical studies,14 was also clearly associated with hypoxaemia. These two signs are characteristic of severe ARI, which was the most prevalent diagnosis. In contrast with another study, head-nodding was not a significant predictor of hypoxaemia.3 A possible explanation for this finding might have been the small number of very young patients who presented with obstructive disease in the study, as head-nodding is often associated with this condition. Cyanosis, which is generally poorly detected by health-care workers, was also found to be
a predictor of hypoxaemia. In line with several other publications,2,4 fever did not predict hypoxaemia. The main strength of this study is the small number of experienced clinicians who were involved in evaluating the patients admitted to hospital. This strongly improved the quality of the data collected. However, the study was limited by the low number of patients recruited. For instance, there was not enough power to assess the predictive value of some of the clinical signs, such as severe malnutrition. To conclude, the most evident and reliable clinical predictors of hypoxaemia were the clinical features which can be heard or seen (PGS, grunting, severe chestindrawing and cyanosis) and not those which are measured (respiratory rate, temperature). These signs can easily be included in diagnostic guidelines15 and be taught to healthcare workers and even lay personnel. In the absence of a pulse oximeter, the presence of one of these signs in young children with acute lower respiratory tract disease should lead to immediate administration of oxygen.16
Disclaimer statements Contributors None. Funding None. Conflicts of interest None. Ethics approval The study protocol was approved by the ethics committee of the Faculty of Medicine, Lausanne University, Switzerland (No. 158/01) and by the medical chief of the Departement of Podor, Senegal.
Acknowledgments The authors thank Dr P. K. Gaye of Ndioum Hospital, Dr Ch. Hanne of Podor De´partement, Senegal, Dresse Ce´line Fischer-Fumeaux, DMCP, CHUV-Lausanne,
Paediatrics and International Child Health
2015
VOL .
35
NO .
1
67
Wandeler et al.
Clinical signs of hypoxaemia
Professor D. Sow, former medical chief of Pediatrics, Dakar, Se´ne´gal for their time and support.
9
References 1 UNICEF. Pneumonia: the forgotten Killer of Children.: UNICEF. Geneva: WHO, 2006. 2 Usen S, Weber M, Mulholland K, Jaffar S, Oparaugo A, Omosigho C, et al. Clinical predictors of hypoxaemia in Gambian children with acute lower respiratory tract infection: prospective cohort study. Br Med J. 1999;318:86–91. 3 Laman M, Ripa P, Vince J, Tefuarani N. Head nodding predicts mortality in young hypoxaemic Papua New Guinean children with acute lower respiratory tract infection. J Trop Pediatr. 2013;59:75–6. 4 Smyth A, Carty H, Hart CA. Clinical predictors of hypoxaemia in children with pneumonia. Ann Trop Paediatr. 1998;18:31–40. 5 Ayieko P, English M. In children aged 2–59 months with pneumonia, which clinical signs best predict hypoxaemia? J Trop Pediatr. 2006;52:307–10. 6 Rao YK, Midha T, Kumar P, Tripathi VN, Rai OP. Clinical predictors of hypoxemia in Indian children with acute respiratory tract infection presenting to pediatric emergency department. World J Pediatr. 2012;8:247–51. 7 Laman M, Ripa P, Vince J, Tefuarani N. Can clinical signs predict hypoxaemia in Papua New Guinean children with moderate and severe pneumonia? Ann Trop Paediatr. 2005;25:23–7. 8 Zhang L, Mendoza-Sassi R, Santos JC, Lau J. Accuracy of symptoms and signs in predicting hypoxaemia among young
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children with acute respiratory infection: a meta-analysis. Int J Tuberc Lung Dis. 2011;15:317–25. Ginsburg AS, Van Cleve WC, Thompson MI, English M. Oxygen and pulse oximetry in childhood pneumonia: a survey of healthcare providers in resource-limited settings. J Trop Pediatr. 2012;58:389–93. Dyke T, Brown N. Hypoxia in childhood pneumonia: better detection and more oxygen needed in developing countries. Br Med J. 1994;308:119–20. Glas AS, Lijmer JG, Prins MH, Bonsel GJ, Bossuyt PM. The diagnostic odds ratio: a single indicator of test performance. J Clin Epidemiol. 2003;56:1129–35. Gehri M, Gautier E, Sall S, Mbaye A, Cotting J. [Grunting in Senegalese children: a symptom predictive of death or serious illness]. Arch Pediatr. 2001;8:667–8. Lodha R, Bhadauria PS, Kuttikat AV, Puranik M, Gupta S, Pandey RM, et al. Can clinical symptoms or signs accurately predict hypoxemia in children with acute lower respiratory tract infections? Indian Pediatr. 2004;41:129–35.. Chisti MJ, Salam MA, Ashraf H, Faruque AS, Bardhan PK, Shahid AS, et al. Predictors and outcome of hypoxemia in severely malnourished children under five with pneumonia: a case control design. PLoS One. 2013;8:e51376. World Health Organization. Pocket Book of Hospital Care for Children: Guidelines for the Managment of Common Illnesses with Limited Resources. Geneva: WHO, 2005. Duke T, Graham SM, Cherian MN, Ginsburg AS, English M, Howie S, et al. Oxygen is an essential medicine: a call for international action. Int J Tuberc Lung Dis. 2010;14:1362– 8.
Which clinical signs predict hypoxaemia in young Senegalese children with acute lower respiratory tract disease? G. Wandeler1,2,3, J. Y. Pauchard4, E. Zangger3,4, H. Diawara3, M. Gehri3,4 1
Department of Infectious Diseases, University Hospital, Bern, Switzerland, 2Institute of Social and Preventive Medicine, University of Bern, Switzerland, 3Ndioum District Hospital, Senegal, 4Hoˆpital de l’Enfance de Lausanne, Switzerland Background: Acute lower respiratory tract diseases are an important cause of mortality in children in resource-limited settings. In the absence of pulse oximetry, clinicians rely on clinical signs to detect hypoxaemia. Objective: To assess the diagnostic value of clinical signs of hypoxaemia in children aged 2 months to 5 years with acute lower respiratory tract disease. Methods: Seventy children with a history of cough and signs of respiratory distress were enrolled. Three experienced physicians recorded clinical signs and oxygen saturation by pulse oximetry. Hypoxaemia was defined as oxygen saturation ,90%. Clinical predictors of hypoxaemia were evaluated using adjusted diagnostic odds ratios (aDOR). Results: There was a 43% prevalence of hypoxaemia. An initial visual impression of poor general status [aDOR 20.0, 95% CI 3.8–106], severe chest-indrawing (aDOR 9.8, 95% CI 1.5–65), audible grunting (aDOR 6.9, 95% CI 1.4–25) and cyanosis (aDOR 26.5, 95% CI 1.1–677) were significant predictors of hypoxaemia. Conclusion: In children under 5 years of age, several simple clinical signs are reliable predictors of hypoxaemia. These should be included in diagnostic guidelines.
Keywords: Under-5 children, Acute lower respiratory disease, Hypoxaemia, Pulse oximetry
Introduction Acute respiratory infections (ARI) are one of the most important causes of mortality in children aged 2 months to 5 years in resource-limited settings.1 In the severest cases, these children develop hypoxaemia, which is predictive of death.2 To date, no consensus has been reached on the importance of specific clinical predictors of hypoxaemia in children with acute respiratory disease, despite the publication of several reports on the subject.2–7 In their systematic review and meta-analysis of the accuracy of symptoms and signs in predicting hypoxaemia in children, Zhang et al. found only 11 studies and there was high Heterogeneity in the results across the studies.8 As the administration of oxygen is of primary importance in these situations, hypoxaemia has to be detected rapidly. Measurement oxygen saturation with a portable pulse oximeter is a reliable method of diagnosing hypoxaemia in children; however, it is rarely available in resource-limited Correspondence to: M Gehri, Hoˆ pital de l’Enfance de Lausanne, De´partement Me´dico-chirurgical de Pe´diatrie, Avenue de Monte´tan 1007, Lausanne, Switzerland. Email: [email protected]
ß W. S. Maney & Son Ltd 2015 DOI 10.1179/2046905514Y.0000000153
settings.9 Therefore, it is essential to provide healthcare workers with the means to rely on clinical signs of hypoxaemia so that these patients can be referred to health care facilities with access to oxygen therapy.10 This study aimed to assess the diagnostic value of different clinical signs of hypoxaemia in children with acute lower respiratory distress.
Subjects and Methods Children between the ages of 2 months and 5 years with acute lower respiratory tract distress caused by respiratory infections or wheezing diseases (asthma, bronchitis) who presented to the paediatric emergency ward of Ndioum Hospital in rural Senegal were enrolled prospectively between June 2002 and January 2003. All the children were evaluated on admission for general signs as well as the symptoms and signs of respiratory distress by one of three senior physicians. Hypoxaemia was defined as oxygen saturation (SaO2) ,90%. SaO2 was measured using a Nellcor NPB-40 portable pulse oximeter (Ndioum Hospital is 12 m above sea level). Several clinical signs and parameters were assessed during physical examination (Table 1).
Paediatrics and International Child Health
2015
VOL.
35
NO.
1
65
Wandeler et al.
Clinical signs of hypoxaemia
Table 1 Description of clinical signs and characteristics Clinical signs and parameters
Remarks
General signs Poor general status
First visual impression: looks bad/looks good, severe lethargy or reduced level of consciousness
Inability to cry
Test of giving something to drink during examination
Inability to drink Visible and/or audible respiratory signs
Nasal flaring Central cyanosis Head-nodding
Head-nodding is defined as head movements that are synchronous with each breath and are due to contractions of accessory muscles of respiration See-saw breathing, visible at first sight Audible without stethoscope Audible at mouth and/or with stethoscope
Measurements
Severe chest-indrawing Grunting Wheezing Temperature (rectal)
Abnormal if >38uC
Respiratory rate
If .70/min, pathological at all ages, counted over 1 min, child calm, nose not blocked ,70%, severe acute malnutrition
Weight-for-height ratio
Statistical analysis
The study protocol was approved by the ethics committee of the Faculty of Medicine, Lausanne University, Switzerland (Comite´ d’Ethique de la Faculte´ de Me´decine de Lausanne, No. 158/01) and by the medical chief of the De´partement of Podor, Senegal.
Statistical analyses were performed using Epi-Info, version 2012. The patients were classified into two groups according to their oxygen saturation level – non-hypoxaemic vs. hypoxaemic. The proportions of patients with each clinical sign or symptom were evaluated. Sensitivity, specificity, positive predictive value, negative predictive value and the diagnostic odds ratio (DOR), a single indicator of diagnostic performance,11 were used as measures of diagnostic value of each clinical sign. The analyses were performed separately for each clinical sign or symptom, and using a multivariable logistic regression model adjusted for age and all clinical signs and symptoms with a statistically significant DOR (P , 0.05) in univariate analysis.
Results Seventy children aged 2 months to 5 years were included in the study (33 girls, 37 boys). The median age was 17.4 months. Five children (7%) were severely malnourished (weight for height ,70%) and seven (10%), all hypoxaemic, died shortly after admission. The majority of children were diagnosed with infectious respiratory diseases (n 5 44, 63%), including pneumonia and bronchiolitis, and the rest (n 5 26, 37%) with wheezing diseases such as
Table 2 Distribution of type of acute lower respiratory tract disease (ALRD) and related prevalence of hypoxaemia (SaO2 ,90%) Type of ALRD
No. of patients (%)
Hypoxaemic patients* n (%)
Pneumonia Bronchiolitis Bronchitis with wheeze Any others ALRD Total
34 10 14 12 70
20 5 3 2 30
(49) (14) (20) (17) (100)
* SaO2 ,90%.
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2015
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(59) (50) (21) (17) (43)
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Clinical signs of hypoxaemia
Table 3 Clinical predictors of hypoxaemia in 70 children (SaO2 ,90%) Prevalence n (%) General clinical signs Poor general status 40 (58) Inability to cry 28 (40) Inability to drink 54 (77) Temperature .38Cu 29 (41) Severe malnutrition 5 (7) (W/H ,70%) Respiratory distress signs Nasal flaring 51 (72) Cyanosis 11 (15) Head-nodding 23 (32) Severe 48 (68) chest-indrawing Grunting 27 (38) Wheezing 41 (59) Tachypnoea 11 (16) (RR .70/min)
Sensitivity, % (95% CI)
Specificity, % (95% CI)
PPV, % (95% CI)
NPV, % (95% CI)
DOR, % (95% CI)
aDOR{ % (95% CI)
90 63 83 53 7
(79–100) (46–81) (70–97) (35–71) (0–16)
68 78 28 68 93
(53–82) (65–90) (14–41) (53–82) (84–100)
68 68 46 55 40
(53–82) (51–85) (33–60) (37–73) (3–83)
90 74 69 66 57
(79–100) (61–87) (46–91) (51–80) (45–69)
18 5.9 1.8 2.3 0.8
(4.8–73)* (2–16)* (0.5–6.2) (0.8–6.2) (0.1–5.6)
20 (3.8–106)* 1.2 (0.3–5)
93 33 43 93
(84–100) (16–50) (26–61) (84–100)
43 98 75 50
(27–58) (93–100) (62–88) (35–65)
55 91 57 58
(41–69) (74–100) (36–77) (44–72)
89 66 64 91
(76–100) (54–78) (50–78) (79–100)
10 19 2.2 14
(2.1–49)* (2.3–113)* (0.8–6.3)* (2.9–66)*
4.5 26 0.5 9.9
67 (50–84) 66 (48–83) 27 (11–42)
83 (71–94) 45 (30–60) 93 (84–100)
74 (58–91) 46 (31–62) 73 (46–99)
77 (64–89) 64 (47–82) 63 (50–75)
9.4 (3–28)* 1.5 (0.5–4) 4.5 (1.1–18)*
(0.4–46) (1–677)* (0.1–2.8) (1.4–65)*
6 (1.4–25)* 3.2 (0.4–27)
PPV, positive predictive value; NPV, negative predictive value; DOR, diagnostic odds ratio; aDOR, adjusted diagnostic odds ratio; CI, confidence interval; W/H, weight/height ratio; RR, respiratory rate; * P , 0.05; { adjusted with multiple logistic regression for age and other variables significant on univariate analysis.
asthma (Table 2). Overall, 30 children (43%) were hypoxaemic. Of all the patients, 58% were of poor general status (PGS), 41% were febrile, 77% were unable to drink and 40% unable to cry during examination (Table 3). Nasal-flaring (72%), severe chest-indrawing (68%) and wheezing (59%) were the signs of respiratory distress most frequently observed. In univariable analyses, PGS, inability to cry, cyanosis, headnodding, severe chest-indrawing and grunting predicted hypoxaemia. However, in adjusted analyses, only PGS (aDOR 20, 95% CI 3.8–106), severe chestindrawing (aDOR 9.9, 1.5–65), cyanosis (aDOR 26, 1.1–677) and grunting (aDOR 6, 1.4–25) were significant predictors of hypoxaemia (Table 3).
Discussion In this study of young children in rural Senegal with respiratory distress, four clinical signs were strongly predictive of hypoxaemia: PGS, grunting, severe chest indrawing and cyanosis. The results confirm the findings of previous studies demonstrating the importance of grunting in the evaluation of a child with acute respiratory distress.12,13 Severe chest-indrawing, which has been less emphasised in clinical studies,14 was also clearly associated with hypoxaemia. These two signs are characteristic of severe ARI, which was the most prevalent diagnosis. In contrast with another study, head-nodding was not a significant predictor of hypoxaemia.3 A possible explanation for this finding might have been the small number of very young patients who presented with obstructive disease in the study, as head-nodding is often associated with this condition. Cyanosis, which is generally poorly detected by health-care workers, was also found to be
a predictor of hypoxaemia. In line with several other publications,2,4 fever did not predict hypoxaemia. The main strength of this study is the small number of experienced clinicians who were involved in evaluating the patients admitted to hospital. This strongly improved the quality of the data collected. However, the study was limited by the low number of patients recruited. For instance, there was not enough power to assess the predictive value of some of the clinical signs, such as severe malnutrition. To conclude, the most evident and reliable clinical predictors of hypoxaemia were the clinical features which can be heard or seen (PGS, grunting, severe chestindrawing and cyanosis) and not those which are measured (respiratory rate, temperature). These signs can easily be included in diagnostic guidelines15 and be taught to healthcare workers and even lay personnel. In the absence of a pulse oximeter, the presence of one of these signs in young children with acute lower respiratory tract disease should lead to immediate administration of oxygen.16
Disclaimer statements Contributors None. Funding None. Conflicts of interest None. Ethics approval The study protocol was approved by the ethics committee of the Faculty of Medicine, Lausanne University, Switzerland (No. 158/01) and by the medical chief of the Departement of Podor, Senegal.
Acknowledgments The authors thank Dr P. K. Gaye of Ndioum Hospital, Dr Ch. Hanne of Podor De´partement, Senegal, Dresse Ce´line Fischer-Fumeaux, DMCP, CHUV-Lausanne,
Paediatrics and International Child Health
2015
VOL .
35
NO .
1
67
Wandeler et al.
Clinical signs of hypoxaemia
Professor D. Sow, former medical chief of Pediatrics, Dakar, Se´ne´gal for their time and support.
9
References 1 UNICEF. Pneumonia: the forgotten Killer of Children.: UNICEF. Geneva: WHO, 2006. 2 Usen S, Weber M, Mulholland K, Jaffar S, Oparaugo A, Omosigho C, et al. Clinical predictors of hypoxaemia in Gambian children with acute lower respiratory tract infection: prospective cohort study. Br Med J. 1999;318:86–91. 3 Laman M, Ripa P, Vince J, Tefuarani N. Head nodding predicts mortality in young hypoxaemic Papua New Guinean children with acute lower respiratory tract infection. J Trop Pediatr. 2013;59:75–6. 4 Smyth A, Carty H, Hart CA. Clinical predictors of hypoxaemia in children with pneumonia. Ann Trop Paediatr. 1998;18:31–40. 5 Ayieko P, English M. In children aged 2–59 months with pneumonia, which clinical signs best predict hypoxaemia? J Trop Pediatr. 2006;52:307–10. 6 Rao YK, Midha T, Kumar P, Tripathi VN, Rai OP. Clinical predictors of hypoxemia in Indian children with acute respiratory tract infection presenting to pediatric emergency department. World J Pediatr. 2012;8:247–51. 7 Laman M, Ripa P, Vince J, Tefuarani N. Can clinical signs predict hypoxaemia in Papua New Guinean children with moderate and severe pneumonia? Ann Trop Paediatr. 2005;25:23–7. 8 Zhang L, Mendoza-Sassi R, Santos JC, Lau J. Accuracy of symptoms and signs in predicting hypoxaemia among young
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