[A patient who manifested various symptoms following severe accidental hypercapnia]

A case of severe accidental hypercapnia during anesthesia is presented. A 44-year-old woman underwent laparotomy under general anesthesia. Forty minutes after the start of the operation, BP rose slightly and HR increased from 110 to 140 x min-1. Then ST segment depression was noted on ECG monitor. Therefore, nitrous oxide was discontinued for 20 minutes. Frequent oxygen supply with oxygen flush was needed to inflate the collapsed bag. The operation was concluded without additional clinical problems. The patient remained unconscious after the anesthetics were discontinued. Cyanosis was observed despite the delivery of 100% oxygen. Cardiac arrest occurred following abrupt bradycardia, but she responded immediately to resuscitation. She was in a deep comatose state and did not respond to painful stimuli. The pupils were fully dilated with absent light reflex. Arterial blood gas analysis revealed; pH 6.720, PaCO2 277 mmHg, PaO2 159 mmHg, and BE-16.2. Disconnection of anesthetic circuit was noted, thereafter, and hyperventilation was performed. Then, the pupils became promptly constricted and the response to painful stimuli appeared within 30 minutes. Her level of consciousness recovered completely after 4.5 hours of hyperventilation. She suffered from refractory hypotension (BP70-85 mmHg in systolic pressure) in spite of catecholamine administration, tachycardia (HR 140-160 x min-1) and ARDS in the ICU, but all the symptoms disappeared by the 16 hours after ICU admission.