Hypoxemia, Breathing Difficulty May Indicate Pneumonia in Children

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Hypoxia, grunting, nasal flaring, and retractions were all associated with pneumonia diagnosis in pediatric patients.
Hypoxia, grunting, nasal flaring, and retractions were all associated with pneumonia diagnosis in pediatric patients.

In a systematic review of 23 studies worldwide, no single finding could reliably distinguish pneumonia from other pediatric respiratory illnesses, reports the Journal of the American Medical Association.1 However, researchers found that hypoxemia and increased work of breathing were more indicative of pneumonia in children than tachypnea and auscultatory findings.

Sonal N. Shah, MD, MPH, from Boston Children's Hospital and Harvard Medical School, in Boston, Massachusetts, and colleagues sought to determine the key signs and symptoms of pneumonia in children without the aid of radiographic findings. In the absence of a definitive test to determine whether the pneumonia is bacterial or nonbacterial, clinicians rely on radiographs and a combination of signs and symptoms.2

Because pneumonia is a leading cause of death in children younger than 5, it is critical to quickly diagnose and treat it.3 Although the overprescribing of broad-spectrum antibiotics for children with respiratory inspections is declining, approximately 50% of children still receive inappropriate therapy.4 

A search of MEDLINE and Embase studies from 1956 to May 2017 yielded 23 high-quality trials (N=13,833). Shah and colleagues calculated the likelihood ratios (LR), sensitivity, and specificity for individual symptoms of pneumonia, which was confirmed by an infiltrate on chest radiographs. The predetermined thresholds, a positive LR ≥2.0, or a negative LR ≤0.5, were deemed clinically meaningful.

Of all the physical findings, work of breathing had the highest positive LR for pneumonia, specifically grunting (positive LR, 2.7; 95% CI, 1.5-5.1; pooled specificity, 95%), nasal flaring (positive LR, 2.2; 95% CI, 1.3-3.1; pooled specificity, 84%), and chest retractions (positive LR, 1.9; 95% CI, 1.2-2.5; pooled specificity, 80%). Among the vital signs, hypoxemia ≤96% had the strongest association with pneumonia, with a positive LR of 2.8 (95% CI, 2.1-3.6; specificity, 77%).

Tachypnea (respiratory rate >40 breaths/minute) was associated with pneumonia; when reported by age-specific rates, it was not indicative of pneumonia. The wide variation in auscultatory findings in the studies were not positively associated with pneumonia.

The most common symptoms across the 23 studies were cough and fever, reported in 80% of children, although neither sign could definitely determine the presence of pneumonia. The rate of radiograph-confirmed pneumonia in the 8 North American studies was 19% and 37% in the 15 studies outside North America.

“In settings where chest radiography is not readily available, increased work of breathing and hypoxemia can be used to identify children with pneumonia,” the researchers explained. “In settings where pneumonia is commonly diagnosed radiographically, these clinical findings can be used to guide judicious use of chest radiography.”

Summary & Clinical Applicability

While no one sign accurately predicted pneumonia in children, hypoxemia and increased work of breathing were found to be more reliable predictors of pneumonia than tachypnea and auscultatory findings. In resource-scarce locations that do not have access to imaging, hypoxemia and increased work of breathing might raise the clinical suspicion of pneumonia and enable clinicians to provide more timely treatment. 

Limitations & Disclosures

  • Although the studies included in the analysis recruited children aged 0 to 21 years, most of the children were younger than 6 years of age.
  • Due to the worldwide locations of the studies, there were wide variations in medical history and physical examination data

Richard G. Bachur, MD, reports receipt of royalties from UpToDate.com (editorial duties) and Wolters-Kluwer (textbook editor); a stipend as the medical editor for the American Board of Pediatrics Sub-board of Pediatric Emergency Medicine; and research funded by Astute Medical related to biomarkers of appendicitis. David L. Simel, MD, reports receipt of honoraria for contributions to JAMAEvidence.com. Mark I. Neuman, MD, MPH, reports receipt of royalties from UpToDate.com for content unrelated to this manuscript and receives a stipend for his service as an Assistant Editor for Pediatrics.

References

  1. Shah SN, Bachur RG, Simel DL, Neuman MI. Does this child have pneumonia? The rational clinical examination systematic review. JAMA. 2017;318(5):462-471. doi:10.1001/jama.2017.9039
  2. Lynch T, Bialy L, Kellner JD, et al. A systematic review on the diagnosis of pediatric bacterial pneumonia: when gold is bronze. PLoS One. 2010;5(8):e11989. doi:10.1371/journal.pone.0011989
  3. Liu L, Oza S, Hogan D, et al. Global, regional, and national causes of child mortality in 2000-13, with projections to inform post-2015 priorities: an updated systematic analysis. Lancet. 2015;385(9966):430-440. doi:10.1016/S0140-6736(16)31593-8
  4. Gerber JS, Prasad PA, Fiks AG, et al. Effect of an outpatient antimicrobial stewardship intervention on broad-spectrum antibiotic prescribing by primary care pediatricians: a randomized trial. JAMA. 2013;309(22):2345-2352. doi:10.1001/jama.2013.6287

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