Mortality rates decreasing in cystic fibrosis patients treated with invasive mechanical ventilation
Mortality rates in adults with cystic fibrosis treated with invasive mechanical ventilation have decreased over time, suggesting mechanical ventilation in these patients is not futile.
“Other studies have shown that survival to hospital discharge is associated with signiﬁcant posthospitalization survival,” researchers wrote. “Although the decision to intubate patients with cystic fibrosis (CF) remains difﬁcult, our study provides further evidence on outcomes and can help the CF team, family, and the patient weigh the risks and beneﬁts of invasive mechanical ventilation (IMV).”
Researchers examined 1,711 patients with cystic fibrosis undergoing invasive mechanical ventilation from the U.S. Nationwide Healthcare Cost and Utilization Project database between 2002 and 2014. They excluded patients who were pregnant, had nonurgent or nonemergent admissions or encounters that were related to lung transplantation. Age group, calendar year, sex, race, primary expected payer, primary diagnosis and comorbidity were analyzed for each admission and the Cochran-Armitage trend test was used to determine mortality rates. The primary outcome was in-hospital mortality over the course of the study period. Change in annual mortality rates as well as associations between cystic fibrosis covariates and hospital mortality were also assessed.
Investigators used multivariate mixed-effects logistic regression to account for potential differences in in-hospital mortality patterns. The analysis accounted for variables known to be associated with survival in cystic fibrosis, including sex, age, race, insurance status, acute renal failure, diabetes, malnutrition, hospital region, noninvasive positive pressure ventilation and invasive mechanical ventilation treatment lasting longer than 96 hours.
Of the patients analyzed, 762 (44.5%) died, with the annual mortality per hospitalization ranging from 29.9% to 55.3% across the 12-year analysis. Acute renal failure (OR = 1.99; 95% CI, 1.32–3.01), female sex (OR = 1.54; 95% CI, 1.14–2.09) and malnutrition (OR = 1.44; 95% CI, 1.01-2.06) were significantly associated with mortality. Mortality declined overall throughout the study, with the likelihood of survival per hospitalization steadily increasing in tandem with the calendar year (P = .0029). In univariate analysis, invasive mechanical ventilation treatment longer than 96 hours was linked to higher mortality (OR = 1.51; 95% CI, 1.14–1.98), but the association was no longer statistically significant when adjusted for confounders (OR = 1.05; 95% CI, 0.77–1.43).
“Although we hypothesize that mortality in this group of patients is improving over time because of improvement in disease-speciﬁc therapies, other etiologies are possible,” the researchers wrote. “For example, ICU survival for other conditions, such as acute respiratory distress syndrome, has improved over a similar time period. This suggests the possibility that the improvement may be caused by system-level practices within critical care itself.” – by Eamon Dreisbach
Disclosures: One author reports he has received grants from Cystic Fibrosis Foundation and personal fees from Vertex Pharmaceuticals and Gilead Sciences. The other authors report no relevant financial disclosures.