title: Persistent hypothermia after intrathecal morphine: case report and literature review.
abstract: OBJECTIVE
  To describe a case of persistent hypothermia following spinal anesthesia with intrathecal morphine.
  
  
  METHODS
  Following elective right total knee arthroplasty under spinal anesthesia with isobaric 0.5% bupivacaine 11 mg, fentanyl 15 μg, and preservative-free morphine 150 μg, a 57-yr-old female (93.5 kg, 151 cm) developed postoperative hypothermia with a nadir rectal temperature of 33.6°C four hours after surgery. At times, her temperature could not be measured by tympanic, temporal arterial, oral, axillary, or rectal routes. In spite of the low temperature, the patient complained of feeling hot and was diaphoretic without shivering. With the exception of her temperature, her vital signs were normal postoperatively, and aside from hyperglycemia, complete blood count, electrolytes, thyroid-stimulating hormone, serum cortisol, troponin, and twelve-lead electrocardiogram were normal. Her temperature did not respond to warming efforts with a forced-air warming blanket, infusion of warmed intravenous crystalloid, and hourly bladder irrigation with warm saline through an indwelling urinary catheter. Normothermia returned after she received a small dose of sublingual lorazepam eight hours after surgery. The remainder of her postoperative stay was uneventful.
  
  
  CONCLUSIONS
  Patients undergoing spinal anesthesia with intrathecal morphine may develop postoperative hypothermia that is resistant to warming measures. This complication may be treated successfully with lorazepam.
authors.affiliation: Department of Anesthesia, Vancouver Acute, Vancouver, BC, Canada.
authors.forename: Kenneth F
authors.initials: KF
authors.lastname: Ryan
authors.forename: James W
authors.initials: JW
authors.lastname: Price
authors.forename: C Brian
authors.initials: CB
authors.lastname: Warriner
authors.forename: Peter T
authors.initials: PT
authors.lastname: Choi
mesh_terms: D000775:Anesthesia, Spinal / Q000009:adverse effects*; D001833:Body Temperature Regulation / Q000187:drug effects; D005260:Female; D006801:Humans; D007031:Hypothalamus / Q000502:physiology; D007035:Hypothermia / Q000139:chemically induced* / Q000188:drug therapy; D007278:Injections, Spinal; D008140:Lorazepam / Q000627:therapeutic use; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage / Q000009:adverse effects*; D011183:Postoperative Complications / Q000139:chemically induced*; D018079:Receptors, GABA / Q000502:physiology
chemical_list: D018079:Receptors, GABA; D009020:Morphine; D008140:Lorazepam