Article Text

Download PDFPDF
Benzodiazepine Premedication Causes Hypoxemia during Spinal Anesthesia in Geriatric Patients
  1. HernÁN R. MuÑOz*,
  2. Jorge A. Dagnino**,
  3. Jorge A. Rufs and
  4. Guillermo J. Bugedo*
  1. From the Departamento de Anestesiología, Hospìtal Clínico Universidad Católica de Chile.
  2. *Instructor in Anesthesiology.
  3. **Associate Professor of Anesthesiology.
  4. Resident in Anesthesiology.
  1. Address correspondence to Hernán R. Muñoz, Instructor in Anesthesiology, Departamento de Anestesiología, Hospìtal Clínico Universidad, Católica de Chile, PO Box 114-D, Santiago, Chile.


Background and Objectives. The use of sedatives during regional anesthesia can lead to life-threatening hypoxemia. Older patients particularly are prone to enhanced effects of these drugs. We studies whether oral premedication with benzodiazepines produced hypoxemia during spinal anesthesia in elderly patients.

Methods. In a prospective, double-blind, and randomized study, we evaluated the effect of oral benzodiazepine premedication on the incidence of hypoxemia measured by pulse oximetry (arterial oxygen saturation < 90% for 30 seconds or longer) during surgery under spinal anesthesia in 80 geriatric patients divided into four equal groups: 1, control, no premedication; 2, 1 mg flunitrazepam; 3, 1 mg lorazepam; and 4, 7.5 mg midazolam.

Results. The incidence of hypoxemia in the four groups was: 1, 15%; 2, 45%; 3, 20%; and 4, 60% ( p = 0.0078); overall incidence was 42% in premedicated patients versus 15% in unpremedicated controls ( p = 0.0304). Seventy-four percent of patients who presented drowsiness and anesthetic level above T7 had desaturation compared to only 7% of those who were awake and had lower level ( p < 0.0005). No association between hypoxemia and other factors (age, weight, ASA physical status, and position during surgery) was found. All the episodes of desaturation were easily corrected with low supplemental oxygen concentrations.

Conclusions. Premedication with oral benzodiazepines may produce hypoxemia during spinal anesthesia in elderly patients. Lorazepam appeared safer than flunitrazepam and midazolam. Monitoring of arterial blood oxygen saturation and/or supplemental oxygen is mandatory in geriatric patients with high spinal anesthetic level and/or drowsiness during surgery.

  • Anesthesia
  • geriatric
  • premedication
  • benzodiazepines
  • lorazepam
  • midazolam
  • flunitrazepam
  • oxygen monitoring
  • pulse oximetry
  • anesthetic techniques
  • spinal.

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.