Remifentanil improves breathing pattern and reduces inspiratory workload in tachypneic patients

Respir Care. 2011 Jun;56(6):827-33. doi: 10.4187/respcare.01014. Epub 2011 Feb 11.


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 P(aCO(2)) showed a small and clinically negligible increase during remifentanil, but P(aCO(2)) 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. ( registration NCT00665119.)

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Aged
  • Aged, 80 and over
  • Dyspnea / drug therapy*
  • Female
  • Humans
  • Hypnotics and Sedatives / therapeutic use*
  • Male
  • Piperidines / therapeutic use*
  • Remifentanil
  • Respiration, Artificial
  • Statistics, Nonparametric
  • Ventilator Weaning
  • Work of Breathing*


  • Hypnotics and Sedatives
  • Piperidines
  • Remifentanil

Associated data