Recognizing myxedema coma
Two years later she is drowsy and hard to rouse after stopping her levothyroxine for months, with a temperature of 34.6 °C (94.3 °F), heart rate 46/min, respiratory rate 9/min, and sodium 126 mEq/L. These findings indicate myxedema coma, the life-threatening extreme of hypothyroidism. Sedatives are avoided because slowed drug metabolism and hypoventilation make even small doses dangerous. The lorazepam order is the one the nurse questions.
Why sedatives are dangerous here
Severe hypothyroidism slows metabolism throughout the body, including the hepatic breakdown of drugs. A benzodiazepine therefore has a stronger and longer effect than usual. At the same time, she is already hypoventilating with a respiratory rate of 9, and her consciousness is depressed. Even a small dose of lorazepam can deepen stupor, worsen respiratory depression, and precipitate respiratory arrest. Hypothermia, bradycardia, and hyponatremia add to her fragility.
| Order | Appropriate? | Reason |
|---|
| IV levothyroxine loading dose | Yes | Core treatment of myxedema coma |
| IV hydrocortisone every 8 hours | Yes | Given until adrenal insufficiency is excluded |
| Warm blankets, passive rewarming | Yes | Recommended; active warming can cause collapse |
| IV lorazepam as needed | Question | Deepens stupor and respiratory depression |
Why the other orders are appropriate
Intravenous levothyroxine is the core treatment, because oral absorption is unreliable in this state. Intravenous hydrocortisone is given until coexisting adrenal insufficiency is excluded, because thyroid hormone replacement increases cortisol demand and can precipitate adrenal crisis. Passive rewarming with blankets is recommended; aggressive active warming can cause peripheral vasodilation and circulatory collapse. Ventilatory support is provided as needed.
Nursing care
The nurse monitors airway, breathing, cardiac rhythm, temperature, blood glucose, sodium, and level of consciousness closely, often in an intensive care setting. Fluids are given cautiously because of hyponatremia and cardiac strain.
Exam takeaway
Key point In myxedema coma, avoid sedatives and opioids, rewarm passively, and give IV levothyroxine with hydrocortisone. A sedative order is the one to question.