Patient comfort during pressure support and volume controlled-continuous mandatory ventilation

Respir Care. 2008 Jul;53(7):897-902.

Abstract

Background: Pressure-support ventilation (PSV) is more comfortable than volume controlled-continuous mandatory ventilation (VC-CMV) in acute hypercapnic respiratory failure, in patients undergoing noninvasive ventilation. Physiologic measurements of patient status have been compared in PSV and VC-CMV in endotracheally intubated patients, but patient perception of comfort has not been measured in this population.

Objective: To determine if PSV is more comfortable than VC-CMV (volume-cycled, flow-limited) in intubated mechanically ventilated patients.

Methods: In a randomized prospective trial, patients underwent PSV and VC-CMV for 30 min each, separated by a 30 min washout with the baseline ventilation mode (pressure-regulated volume-control ventilation [PRVC]). The level of pressure support was set as the plateau pressure on VC-CMV with a tidal volume of 8 mL/kg minus the end-expiratory pressure. After each mode the patient was asked to mark his or her comfort level on a visual analog scale.

Results: Eleven of the 14 patients were more comfortable during PSV. The baseline mean comfort score (during PRVC) was 62 +/- 18 (95% confidence interval 51.7-72.5). The mean comfort score for PSV was 83 +/- 11 (95% confidence interval 76.9-89.6). The mean comfort score for VC-CMV was 70 +/- 18 (95% confidence interval 59.4-79.9). PSV was significantly more comfortable than VC-CMV (p = 0.02) or PRVC (p = 0.009), whereas the comfort scores for VC-CMV and PRVC were not significantly different (p = 0.278). Respiratory rate, blood pressure, heart rate, minute ventilation, and blood oxygen saturation showed no difference between PRVC, VC-CMV, and PSV.

Conclusions: On average the patients felt more comfortable during PSV than during VC-CMV or PRVC, so PSV may be the preferred mode for awake intubated patients.

Publication types

  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Aged
  • Confidence Intervals
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Middle Aged
  • Patient Satisfaction*
  • Respiration, Artificial / methods*
  • Respiration, Artificial / standards
  • Respiratory Insufficiency / physiopathology
  • Respiratory Insufficiency / therapy*
  • Retrospective Studies
  • Tidal Volume / physiology*
  • Treatment Outcome