Tachypnoea at 60 breaths per minute increases odds of mortality in infants with sepsisRapid breathing in infants linked to higher sepsis mortality

BACKGROUND: Tachypnoea is a danger sign for predicting mortality and identifying sepsis. We systematically reviewed evidence on the diagnostic accuracy of different tachypnoea thresholds for predicting mortality and sepsis in infants aged 0-59 days. METHODS: We searched MEDLINE, Embase, CINAHL, Global Index Medicus and CENTRAL for studies reporting associations or diagnostic accuracy of tachypnoea (≥60, ≥70 or ≥80 breaths per minute (bpm)) for predicting mortality and culture-confirmed sepsis in infants aged 0-59 days. We followed Cochrane methods for study screening, data extraction and quality assessment. We pooled ORs using random-effects models and sensitivity/specificity using random-effects bivariate models. We used GRADE (Grading of Recommendations, Assessment, Development and Evaluation) to assess the certainty of evidence. RESULTS: Of 7641 studies identified, 18 were included (n=92 398). Tachypnoea≥60 bpm had a pooled OR of 3.14 (95% CI 1.30 to 7.56; 5 studies; n=10 407) for predicting mortality and a sensitivity of 31% (95% CI 19% to 45%) and a specificity of 89% (95% CI 66% to 97%; 4 studies; n=7104). For culture-confirmed sepsis, tachypnoea≥60 bpm had an OR of 1.26 (95% CI 0.66 to 2.38; 4 studies; n=3996), and a sensitivity of 28% (95% CI 10% to 58%) and a specificity of 67% (95% CI 53% to 78%; 3 studies; n=693). The higher threshold of tachypnoea≥70 bpm was associated with a higher odds of mortality (OR 10.06 (95% CI 2.39 to 42.35); 2 studies; n=12 138) and resulted in higher specificity (99.4% (95% CI 99.1% to 99.6%)) but lower sensitivity (10.9% (95% CI 5.3% to 19.1%)) for mortality (1 study; n=5214). Data were insufficient to assess performance by age subgroup (0-6 vs 7-59 days). The certainty of evidence was very low. CONCLUSIONS: Tachypnoea≥60 bpm is associated with a threefold increased odds of mortality in young infants, supporting its use as a danger sign. Given its relatively low sensitivity alone, tachypnoea should be interpreted alongside other clinical signs to optimise diagnostic accuracy. While higher thresholds (≥70 bpm) demonstrated stronger associations and increased specificity for predicting mortality, low sensitivity may limit clinical utility. PROSPERO REGISTRATION NUMBER: CRD42023431387.