Lorazepam and midazolam in the intensive care unit: a randomized, prospective, multicenter study of hemodynamics, oxygen transport, efficacy, and cost

Crit Care Med. 1996 Feb;24(2):222-8. doi: 10.1097/00003246-199602000-00007.


Objectives: To evaluate and compare the clinical efficacy, impact on hemodynamic and oxygen transport variables, safety profiles, and cost efficiency of sedation and anxiolysis with lorazepam vs. continuous infusion of midazolam in critically ill, intensive care unit patients.

Design: Multicenter, prospective, randomized, open-label study.

Setting: Teaching hospitals.

Patients: Ninety-five critically ill, mechanically ventilated patients with fiberoptic pulmonary artery catheters in place were randomly assigned to receive short-term (8 hrs) sedation with either intermittent intravenous injection lorazepam (group A, n = 50) or continuous intravenous infusion midazolam (group B, n = 45) titrated to clinical response.

Measurements and main results: The severity of illness, demographic characteristics, levels of anxiety and agitation, hemodynamic parameters, oxygen transport variables, quality of sedation, nursing acceptance, and laboratory chemistries reflecting drug safety were recorded. There were no significant differences with regard to demographic data, hemodynamic and oxygen transport variables, or levels of anxiety/agitation between the two groups at baseline, 5 mins, 30 mins, and 4 and 8 hrs after administration of sedation. There were no significant differences in the quality of sedation or anxiolysis. Midazolam-treated patients used significantly larger amounts of drug for similar levels of sedation and anxiolysis (14.4 +/- 1.2 mg/8 hrs vs. 1.6 +/- 0.1 mg/8 hrs, p = .001). Both drugs were safely administered and patient and nurse satisfaction was similar.

Conclusions: Sedation and anxiolysis with lorazepam and midazolam in critically ill patients is safe and clinically effective. Hemodynamic and oxygen transport variables are similarly affected by both drugs. The dose of midazolam required for sedation is much larger than the dose of lorazepam required for sedation, and midazolam is therefore less cost-efficient.

Publication types

  • Clinical Trial
  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Anti-Anxiety Agents / economics
  • Anti-Anxiety Agents / therapeutic use*
  • Cost-Benefit Analysis
  • Critical Illness*
  • Drug Costs
  • Female
  • Hemodynamics / drug effects*
  • Humans
  • Hypnotics and Sedatives / economics
  • Hypnotics and Sedatives / therapeutic use*
  • Intensive Care Units
  • Lorazepam / economics
  • Lorazepam / therapeutic use*
  • Male
  • Midazolam / economics
  • Midazolam / therapeutic use*
  • Middle Aged
  • Oxygen Consumption / drug effects*
  • Prospective Studies
  • Respiration, Artificial


  • Anti-Anxiety Agents
  • Hypnotics and Sedatives
  • Lorazepam
  • Midazolam