Hypothermia associated with intrathecal morphine

Hypothermia With Paradoxical Symptoms: A Case Series of Cesarean Deliveries With Intrathecal Morphine

Women receiving intrathecal morphine for cesarean delivery may experience hypothermia with paradoxical symptoms of sweating, nausea, and shivering. Despite being relatively rare in comparison to commonly experienced symptoms of perioperative hypothermia, hypothermia with paradoxical symptoms affects early maternal recovery and comfort. The cause is undetermined, and treatment approaches vary. Regular active-warming strategies may not be tolerated because of the paradoxical symptoms of sweating and feeling overheated. This case series aims to explore the phenomenon through the evaluation of health care records of women receiving intrathecal morphine for cesarean delivery at a single, tertiary health care institution in Australia from 2015 to 2018. We also summarize published literature to review treatment approaches used in the care of women experiencing profound heat loss while feeling overheated.

Intrathecal Morphine-Related Perioperative Hypothermia in Women Undergoing Cesarean Delivery: A Retrospective Case-Control Study

PURPOSE

Rates of inadvertent perioperative hypothermia among women undergoing spinal anesthesia for cesarean delivery are reported to be high. Intrathecal morphine has been noted to have a potentially potent effect on thermoregulation. This retrospective case-control study sought to investigate the incidence of perioperative hypothermia in women undergoing cesarean delivery with and without intrathecal morphine and to describe any clinical factors associated with the condition, the identification of which would provide direction for nursing priorities in the care of the condition.

DESIGN

A retrospective case-controlled study design was used.

METHODS

The charts of 358 women who had undergone emergency or elective cesarean delivery under spinal anesthesia were reviewed: 179 having received intrathecal morphine and 179 having received spinal anesthesia without intrathecal morphine (control group). SPSS (IBM, Armonk, New York), version 22, was used for data analysis, including logistic regression to predict the outcome of hypothermia across the study population.

FINDINGS

There was no significant difference (P = .62; 95% confidence interval, -0.09 to 0.15) in mean postoperative temperature for the morphine group (mean postanesthesia care unit arrival temperature, 35.91°C; standard deviation, 0.59) and the no morphine group (mean postanesthesia care unit arrival temperature, 35.88°C; standard deviation, 0.52). However, within groups, the temperature decline preoperatively to postoperatively was statistically (and clinically) significant.

CONCLUSIONS

The results refute the suggestion that intrathecal morphine contributes to greater core temperature decline in this population; however, it does confirm that perioperative hypothermia is a prevalent concern for women undergoing cesarean delivery and that pre-emptive measures should be routinely considered by health care providers.

Persistent hypothermia after intrathecal morphine: case report and literature review

PURPOSE

To describe a case of persistent hypothermia following spinal anesthesia with intrathecal morphine.

CLINICAL FEATURES

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.

CONCLUSION

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.