2024 FSA Podium and Poster Abstracts

P086: SEVERE HYPOTHYROIDISM IN THE PARTURIENT: A CASE REPORT
Sydney E Shaouy, MD; Paul D Mongan, MD; University of Florida Health Jacksonville

Background: Untreated hypothyroidism has perioperative implications for nearly every organ system. Many reported cases of hypothyroidism in the perioperative period are those that were unmasked by anesthesia. Untreated hypothyroidism is associated with arrythmias, coronary events, diminished cardiac output, predisposition to hypotension under anesthesia due to beta-adrenergic receptor downregulation, impaired hypoxic and hypercapnic respiratory drive, hyponatremia, decreased gastric motility, normocytic anemia, and decreased clearance of medications due to diminished renal perfusion. In addition, the pregnant state further complicates anesthetic management, due to a multitude of physiologic changes in the parturient including a decrease in minimum alveolar concentration (MAC), enhanced effects of neuraxial analgesia with a higher predisposition to local anesthetic toxicity, increased sensitivity to muscle relaxants and sedatives, decreased systemic vascular resistance, aortocaval compression with predisposition to profound hypotension, decreased apneic reserve, dilutional anemia, and hypercoagulable state. The goal of this report is to discuss potential anesthetic risks in a parturient with profound hypothyroidism, and to propose a safe anesthetic plan for such patients.

Case: A 24-year-old G3P0020 with an intrauterine pregnancy at 37 weeks and 6 days presented in spontaneous labor. Her history was notable for grand mal seizures, anemia, and Grave’s hyperthyroidism status post complete thyroidectomy resulting in post-operative hypothyroidism. On presentation, the patient was found to have marked hypothyroidism on laboratory work-up despite being asymptomatic. The patient reported a lapse in taking her anti-seizure and thyroid medications due to cost; however, she reported that she had been taking levothyroxine during the three weeks prior to presentation. Potential risks of neuraxial and general anesthesia in the setting of possible need for emergent cesarean section were discussed with the patient. The patient was continued on an increased dose of Levothyroxine 125mcg daily given her pregnant state, and no stress dose steroids were administered given her normal vital signs and concerns for steroid effects on the fetus. She delivered a healthy baby girl vaginally using an epidural catheter for pain control.

Conclusion: Hypothyroidism poses many risks for both general and neuraxial anesthesia and is further complicated by the pregnant state. It is important to develop back-up anesthetic plans for safe management, and to discuss these risks with the patient.