Highlights from

ATS 2019

American Thoracic Society international conference

Dallas, USA 17-22 May 2019

Bacterial Pneumonia Predicts Ongoing Lung Problems in Infants Hospitalised for Acute Respiratory Failure

Bacterial pneumonia was found to predict persistent breathing problems in previously healthy infants who were hospitalised for acute respiratory failure. Infants with bacterial pneumonia who left the hospital were also more likely to have lung problems that required supplemental oxygen, bronchodilators, or steroids [1].

Acute respiratory failure (ARF) is one of the most common reasons for admission to a paediatric intensive care unit. The short-term and long-term effects on pulmonary health are unknown, as well as what factors contribute to chronic pulmonary dysfunction. An episode of ARF, severe enough, usually requires mechanical ventilation (MV), further contributing to pulmonary dysfunction. Based on these observations, Dr Garrett Keim (Children’s Hospital of Philadelphia, USA) and colleagues hypothesised that severity of ARF and the course of MV, as well as pulmonary dysfunction at discharge (PDAD) will predict chronic pulmonary dysfunction at 6- and 12-months follow-up.

A cohort of previously healthy infants, >2 years old, who required MV for ARF were prospectively recruited from multiple centres. These infants had an extensive recording of paediatric intensive care unit and hospital course. PDAD was defined as requiring at least one of the following at 28 days of hospital discharge: MV, supplemental oxygen, bronchodilators, or steroids. Follow-up status was determined for 158 (61%) cases at 6 months and 130 (50%) patients at 12 months. Chronic pulmonary dysfunction (CPD) was defined as having a Paediatric Quality of Life score ≥5. Other criteria that determined persistent CPD were being diagnosed with asthma, requiring medication such as bronchodilators or inhaled steroids therapy, or having an unscheduled clinical assessment for respiratory symptoms. Multivariate backward stepwise regression analysis was applied to determine independent predictors of PDAD at hospital discharge and CPD at 6 and 12 months.

PDAD was present in 87 out of 255 (34.1%) infants at hospital discharge. Patients with a positive bacterial culture strongly predicted PDAD upon leaving the hospital (OR 4.38; CI, 1.66-11.56). Furthermore, the nadir oxygenation index was the only ventilator characteristic or severity of illness measure that was found to be a predictor of PDAD (OR 1.07; CI, 1.02-1.12). At 6-month follow-up, 66 out of 158 patients (41.8%) were found to have CPD. At 12 months, CPD was observed in 57 out of 130 (43.8%) infants. The results also showed that CPD at 6 months was strongly predictive of 12 months CPD. These results are summarised in Table 1.

Table 1: Multivariable model for predictors of CPD at 6 and 12 months [1]

VariableOdds ratio95% confidence intervalP value
6 months
Nadir Ol1.061.01-1.120.024
Bacterial culture positive (yes)3.731.39-9.950.009
12 months
CPD at 6 months18.586.68-52.67<0.001
Bacterial culture positive3.541.24-10.080.018

Dr Keim and his team concluded that the development of CPD is common in previously healthy infants experiencing an episode of ARF and in need of MV. A positive bacterial respiratory culture is related to ongoing CPD to at least 12 months follow-up. PDAD predicted CPD at 6 months, which in turn was strongly associated with continued CPD at 12 months.

  1. Keim G, et al. Bacterial Pneumonia Predicts Ongoing Chronic Pulmonary Dysfunction in Previously Healthy Infants. A27, ATS 2019, 17-22 May, Dallas, Texas, USA

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