Invasive mechanical ventilation for acute respiratory failure in children with cystic fibrosis: Outcome analysis and case-control study

The outcome for cystic fibrosis (CF) patients requiring intubation and invasive mechanical ventilation (IMV) due to acute respiratory failure (ARF) has been poor. Mortality rates have been reported as high as 60-90%. However, a review of mortality in children has not been published in 20 years. Our objectives were to study outcomes in CIF patients requiring IMV due to ARF between 1988-1998, compare recent outcomes with those previously reported, and identify risk factors associated with poor outcome. We additionally attempted to identify factors suggesting an increased risk of developing ARF requiring IMV. A retrospective cohort study design was used, comparing IMV survivors and nonsurvivors with a nested case-control study to identify risk factors for ARF leading to IMV. All patients cared for at our Center who required IMV for ARF between 1988-1998 were identified. Outcome, age, steroid use, forced vital capacity (FVC), forced expired volume in 1 sec (FEV1), microbiology, nutritional status, CF-related diabetes (CFRD), liver dysfunction, and history of major hemoptysis (HEM) or pneumothorax (PTX) were recorded. Cases were matched for gender and age with CF controls identified through a clinical database. Thirty-eight episodes of IMV due to ARF were reported in 33 patients. Three subjects underwent IMV on two or more occasions, but only the first episode was included in analysis. Older age was the only factor that was significantly associated with mortality: 9 subjects were <5 years of age (mortality, 22%), while 24 were 5-34 years old (mortality, 75%) (P=0.013). There was an increased risk of having an episode of ARF requiring IMV in malnourished subjects (OR = 4.2; 95% CI = 1.66-10.51) and in those with a history of HEM (OR = 6.3; 95% CI = 1.75-22.65). Infants and young children with CF requiring IMV due to ARF have a favorable prognosis, whereas those >5 years of age suffer significantly higher mortality. Malnutrition and a history of HEM are important risk factors for having an episode of ARF requiring IMV.