TY - JOUR T1 - Remifentanil Improves Breathing Pattern and Reduces Inspiratory Workload in Tachypneic Patients JF - Respiratory Care SP - 827 LP - 833 DO - 10.4187/respcare.01014 VL - 56 IS - 6 AU - Giuseppe Natalini AU - Antonella Di Maio AU - Antonio Rosano AU - Pierluigi Ferretti AU - Michele Bertelli AU - Achille Bernardini Y1 - 2011/06/01 UR - http://rc.rcjournal.com/content/56/6/827.abstract N2 - BACKGROUND: Properly titrated opiates decrease respiratory rate but do not affect tidal volume or induce respiratory acidosis. OBJECTIVE: To determine whether remifentanil improves breathing pattern or reduces inspiratory effort in patients with acute respiratory failure and tachypnea or rapid shallow breathing. METHODS: We studied 14 patients who developed tachypnea and/or rapid shallow breathing if the pressure support level was reduced. During pressure support ventilation, each patient received 30-min infusions, separated by 30 min, of remifentanil and placebo. Measurements were obtained before commencing and before stopping each infusion, and after 3 min of unassisted breathing. The main outcomes were rapid shallow breathing index and change in pressure-time product. RESULTS: Remifentanil did not significantly affect tidal volume. During pressure support ventilation, remifentanil infusion reduced respiratory rate, pressure-time product, and cardiovascular double product (heart rate × systolic arterial pressure) without modifying the sedation score. Mean PaCO2 showed a small and clinically negligible increase during remifentanil, but PaCO2 increased more in the hypercapnic patients than in the normocapnic patients. Remifentanil reduced the rapid shallow breathing index after 3 min of unassisted breathing. CONCLUSIONS: Remifentanil improved respiratory pattern and decreased inspiratory muscles effort in patients with tachypnea or rapid shallow breathing, but did not affect oxygenation or sedation. Though the acid-base balance did not show clinically relevant changes on average, we cannot exclude the possibility that remifentanil might prolong weaning in hypercapnic patients. (ClinicalTrials.gov registration NCT00665119) ER -