Abstract Introduction Insulinoma represents an uncommon pancreatic neuroendocrine tumor, occurring in approximately 1 to 4 cases per million population each year. Its recognition can be delayed in patients with diabetes or critical illness, where metabolic stress and exogenous medications can confuse the biochemical picture. Sulfonylurea exposure can prolong insulin secretion and, in the setting of impaired renal clearance, mask an underlying insulinoma. In pulmonary-critical care practice, hypoglycemia in a patient with obesity hypoventilation syndrome, and respiratory failure presents unique diagnostic and therapeutic challenges. Case Presentation Case of a 54-year-old female with obesity hypoventilation syndrome, severe obstructive sleep apnea, chronic hypercapnic respiratory failure, hypothyroidism, and Type II Diabetes Mellitus that required intensive care unit admission due to acute-on-chronic hypercapnic respiratory failure. While this admission, she developed recurrent fasting and nocturnal hypoglycemia consistent with Wipple's triad. Recent sulfonylurea exposure complicated the diagnostic process in the presence of renal dysfunction, which may have prolonged the duration of hypoglycemia and masked laboratory confirmation of insulinoma. Continuous glucose monitoring (CGM) demonstrated recurrent hypoglycemia despite high-rate dextrose 10% infusion, high-dose glucocorticoids, and octreotide. Diazoxide was held initially due to patient fluid overload and risk of worsening hypoventilation. After aggressive diuresis and clinical stabilization, diazoxide was initiated with carbohydrate-adjusted nutrition, leading to descalation of therapy and resolution of hypoglycemia. Discussion Our cases represent the diagnostic complexity when evaluating hypoglycemia in critically ill patients with pulmonary comorbidities. Obesity hypoventilation-related chronic hypercapnia limited the patient's ability to tolerate prolonged fasting or fluid shifts, and concurrent sulfonylurea exposure confounded the metabolic workup. The need to withhold diazoxide due to volume overload highlights the delicate cardiopulmonary balance required in ICU management. Recognizing the possibility of insulinoma in this context prevented premature attribution of hypoglycemia to medication error or malnutrition. Conclusion Clinicians in critical care must remain alert to rare endocrine causes of recurrent hypoglycemia in complex ICU patients. Sulfonylurea toxicity and impaired renal clearance can mimic or mask insulinoma, delaying diagnosis. A multidisciplinary approach with endocrinology, integration of CGM findings, and cautious metabolic support are key to avoiding neurological complications and directing further evaluation once respiratory status allows. This abstract is funded by: None
Perez et al. (Fri,) studied this question.