Title: Profound Pain Due to Propofol Injection Triggered Myocardial Ischemia in a Patient with a Suspected Pheochromocytoma
Abstract: To the Editor: Propofol-induced pain is one of side effects observed during injection (1). However, to our knowledge, there are no reports of serious accidents associated with propofol-induced pain. We describe a patient who had a suspected pheochromocytoma and developed myocardial ischemia triggered by propofol-induced pain during induction of anesthesia. The patient, a 52-year-old man (height, 165 cm; weight, 55 kg), was scheduled for a laparoscopic adrenalectomy for a suspected pheochromocytoma detected by CT scan at health screening. Preoperative examinations revealed slight increases in plasma catecholamines and 24-hour urinary catecholamines excretion. Preparation involved a period of preoperative α-blockade with prazosin hydrochloride. Before induction, the patient’s hemoglobin was 13.3 g/dL, the electrocardiogram (ECG) findings were within normal limits, baseline heart rate was 65 bpm, and arterial blood pressure was 95/55 mm Hg. Under continuous monitoring of blood pressure through a radial artery catheter, general anesthesia was induced by IV administration of propofol (100 mg/30 s) through the 18-gauge catheter at his forearm. The patient complained of a profound vascular pain during the infusion of propofol. After loss of consciousness, arterial blood pressure increased to 230/130 mm Hg and a sinus tachycardia (130 bpm) was observed. Immediately, 0.5 mg nicardipine and 50 mg propofol combined with inhalation of 2% sevoflurane were administered and his blood pressure normalized. The trachea was intubated after adequate muscle relaxation was attained and simultaneously the ECG in lead II showed an elevation of the ST segment (Fig. 1), then arterial blood pressure decreased to 80/50 mm Hg. After intravenous 0.1-mg phenylephrine and continuous infusion of nitroglycerin (0.5 μg/kg/min), diltiazem (1 μg/kg/min), and dopamine (3 μg/kg/min) were infused, the ST segment returned to normal in 10 min and his blood pressure improved to 110/55 mm Hg. The coronary angiography performed a week later revealed normal coronary arteries. We speculated that propofol-induced pain could cause a sudden increase in plasma catecholamine levels derived from a pheochromocytoma and eventually develop myocardial ischemia. Propofol should be used carefully in such patients.Figure 1: (A) Electrocardiogram recorded before the induction of anesthesia. It revealed a normal sinus rhythm. (B) Immediately after induction of anesthesia, elevation of the ST segment was noted but it normalized in 10 minutes after treatment of hypotension and myocardial ischemia.Tetsuro Morishima, MD Kazuya Sobue, MD, PhD Hajime Arima, MD Sayuki Tanaka, MD MinHye So, MD Hiroshi Ando, MD, PhD Hirotada Katsuya, MD, PhD