Mechanical ventilation with lower tidal volumes does not influence the prescription of opioids or sedatives

Abstract

Introduction: We compared the effects of mechanical ventilation with a lower tidal volume (V(T)) strategy versus those of greater V(T) in patients with or without acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) on the use of opioids and sedatives.

Methods: This is a secondary analysis of a previously conducted before/after intervention study, which consisting of feedback and education on lung protective mechanical ventilation using lower V(T). We evaluated the effects of this intervention on medication prescriptions from days 0 to 28 after admission to our multidisciplinary intensive care unit.

Results: Medication prescriptions in 23 patients before and 38 patients after intervention were studied. Of these patients, 10 (44%) and 15 (40%) suffered from ALI/ARDS. The V(T) of ALI/ARDS patients declined from 9.7 ml/kg predicted body weight (PBW) before to 7.8 ml/kg PBW after the intervention (P = 0.007). For patients who did not have ALI/ARDS there was a trend toward a decline from 10.2 ml/kg PBW to 8.6 ml/kg PBW (P = 0.073). Arterial carbon dioxide tension was significantly greater after the intervention in ALI/ARDS patients. Neither the proportion of patients receiving opioids or sedatives, or prescriptions at individual time points differed between pre-intervention and post-intervention. Also, there were no statistically significant differences in doses of sedatives and opioids. Findings were no different between non-ALI/ARDS patients and ALI/ARDS patients.

Conclusion: Concerns regarding sedation requirements with use of lower V(T) are unfounded and should not preclude its use in patients with ALI/ARDS.

Figure 1

Diagram of the sedation protocol and SEDIC score. ICU, intensive care unit; IV, intravenous; MV, mechanical ventilation; SEDIC, Sedation Intensive Care.

Figure 2

Percentage of patients requiring sedative drugs. Shown are the percentages of patients needing (a) morphine, (b) midazolam, or (c) propofol from days 0 to 28 for patients mechanically ventilated before and after the intervention.