Letters to the Editor

Indian Pediatrics 2002; 39:205-207  

Association of Crackles and/or Wheezing with Tachypnea or Chest Indrawing in Children with Pneumonia

The World Health Organization (WHO) recommends that in developing countries, primary health care workers should use the respiratory rate (tachypnea)(1) for diagnosis of pneumonia and chest indrawing for defining severe pneumonia in children aged below 5 years(2). These signs can be reliably detected by paramedical staff as well as by doctors(3). In several countries bronchial obstruction with or without respiratory infections is a common cause of rapid breathing(4,5). Chest indrawing occurs because of the contraction of the thoracic accessory muscles(6). Any condition that causes either reduced lung compliance, like pneumonia, or increased tissue/airway resist-ance, like asthma, causes chest indrawing(7). Moreover, the prevalence of asthma is increasing globally(8).

From September 1997 to October 1999, we enrolled prospectively 1416 children with radiologically diagnosed pneumonia at the Emergency Room (ER) of the Professor Hosannah de Oliveira Pediatric Center, a university hospital, and at the pediatric ER of the Alianca Hospital, a private setting, in Salvador, Northeast Brazil. Each child was enrolled just once and 198 were excluded because of missing data of one of the studied variables. The primary pediatrician read the chest X-ray during the consultation and collected clinical information.

The median age was 1.3 years (mean 1.7 ± 1.3; range 8 days to 59 months); 5.6% were <2 months of age. There were 56.2% males and 43.8% females. Tachypnea, chest indrawing, crackles and wheezing were reported, respectively, in 65.1%, 45.4%, 67.9% and 46.5% of the cases. In crude analysis, by using chi square, the presence of crackles was associated with tachypnea (67.2% vs 60.6%, p = 0.02) and with chest indrawing (52.5% vs 30.4%, p = 0.000) as well as the presence of wheezing was associated with tachypnea (73.0% vs 58.3%, p = 0.000) and with chest indrawing (61.5% vs 31.4%, p = 0.000).

Besides the association of crackles or wheezing with tachypnea or chest indrawing in crude analysis, this study gave us evidence on the statistical interaction between wheezing and crackles, wheezing being an effect modifier(9) of crackles in children with pneumonia (Tables I and II).

In regions with a high prevalence of wheezing illness, the specificity of the WHO pneumonia algorithm will be reduced and this is likely to lead to some unnecessary use of antibiotics and to under-utilization of bronchodilators(10). The importance of using tachypnea as a diagnostic criterion for childhood pneumonia is the ease of its use by primary health care workers for whom it is not possible to use the stethoscope(1). An audible wheeze was recently appreciated in only 29.3% of the cases with difficult breathing and an auscultable wheeze(5). Two or more earlier similar episodes (sensitivity 84%, specificity 84%) was the best predictor for asthma in a case control study which compared children presenting with pneumonia and asthma(8). Simple clinical features like history of previous similar episode of cough and diffi-cult breathing and fever have been suggested to refine the antibiotic and bronchodilator prescription in the WHO case management algorithm(5). Our results reinforce that these findings must be urgently validated in diverse setting with the ultimate goal of improving the WHO Program for the Control of Acute Respiratory Infections.

* Results are reported in % (n/N); + Chi square.

* Results are reported in % (n/N) + Chi square

This study was supported by the Pan American Health Organization. We thank Leda S. de Freitas Souza, MD, PhD, for her technical assistance in the analysis and every pediatrician, nurse and medical student for collaborating on this study working at the Emergency Room of the participant hospitals.

C.M.C. Nascimento-Carvalho,
H. Rocha*.
Y. Benguigui+,
Department of Pediatrics and
of Internal Medicine*, Faculty of Medicine,
Professor Hosannah de Oliveira Pediatric Center,
Federal University of Bahia;
Aliança Hospital; Salvador, Bahia,
Brazil and Pan American Health Organization+,
Washington DC, USA.

Correspondence to:
Dra. Cristiana Nascimento-Carvalho,
Department of Pediatrics,
Faculty of Medicine,
Federal University of Bahia,
Rua Prof. Aristides Novia,
N0. 105/1201 B-Salvador, Bahia,
Brazil CEP 40210-730.
E-mail: [email protected]

 

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