Plasma 25-Hydroxyvitamin D Levels at Initiation of Care and Duration of Mechanical Ventilation in Critically Ill Surgical Patients.

OBJECTIVE: Limited data exist regarding the relationship between plasma 25-hydroxyvitamin D levels and duration of respiratory support. Our goal was to explore whether vitamin D status at the time of intensive care unit (ICU) admission is associated with duration of mechanical ventilation in critically ill surgical patients.

MATERIALS AND METHODS: We analyzed data from a prospective cohort study involving 210 critically ill surgical patients. To explore the relationship between admission plasma 25-hydroxyvitamin D levels and duration of mechanical ventilation, we performed a Poisson regression while controlling for clinically relevant covariates. Only patients who required ≥48 hours of mechanical ventilation and survived ≥24 hours after discontinuation of respiratory support were included in the analytic cohort.

RESULTS: Ninety-four patients met inclusion criteria. Mean (standard deviation) plasma 25-hydroxyvitamin D level was 16 (7) ng/mL and median (interquartile range) duration of mechanical ventilation was 4 (2-7) days. Poisson regression analysis, adjusted for age, sex, race, body mass index, primary surgical service, Acute Physiology and Chronic Health Evaluation II score, and season of ICU admission, demonstrated an inverse association of plasma 25-hydroxyvitamin D levels with duration of mechanical ventilation (incident rate ratio per 10 ng/mL, 0.66; 95% confidence interval, 0.54-0.82).

CONCLUSIONS: In our cohort of critically ill surgical patients, plasma 25-hydroxyvitamin D levels measured on ICU admission were inversely associated with the duration of respiratory support. Randomized controlled trials are needed to assess whether vitamin D supplementation can influence duration of mechanical ventilation in surgical ICU patients.