Postextubation respiratory events in patients admitted to the intensive care unit: a prospective pilot study using overnight respiratory polygraphy

BACKGROUND: Before the main trial in which respiratory polygraphy will be used to evaluate postextubation sleep apnea in critically ill patients, we performed a prospective pilot study to ensure that any issues with the conduct of the trial would be identified. METHODS: In the present study, 13 adult patients who had received mechanical ventilation for ≥24 hours were prospectively recruited. Among the patients, 10 successfully completed respiratory polygraphy on the first or second night after extubation. Data regarding the types and doses of corticosteroids, analgesics, sedatives, and muscle relaxants as well as the methods of oxygen delivery were recorded. RESULTS: During the night of respiratory polygraphy, all 10 patients received supplemental oxygen (low-flow oxygen, n=5; high-flow oxygen, n=5), and seven patients received intravenous corticosteroids. Three of the 10 patients had a respiratory event index (REI) ≥5/hr. All respiratory events were obstructive episodes. None of the patients receiving high-flow oxygen therapy had an REI ≥5/hr. Two of the seven patients who received corticosteroids and one of the other three patients who did not receive this medication had an REI ≥5/hr. Although low- or high-flow oxygen therapy was provided, all patients had episodes of oxygen saturation (SpO(2)) <90%. Two of the three patients with an REI ≥5/hr underwent in-laboratory polysomnography. The patients’ Apnea-Hypopnea Index and REI obtained via polysomnography and respiratory polygraphy, respectively, were similar. CONCLUSIONS: In a future trial to evaluate postextubation sleep apnea in critically ill patients, pre-stratification based on the use of corticosteroids and high-flow oxygen therapy should be considered.