A brief cardiac arrest due to saline irrigation during surgery for infratentorial cerebellar tumor

provided the original work is properly cited. CC The posterior fossa is surrounded by bone and tentorium, and an infratentorial brain tumor can compress normal brain structures, thus eliciting various symptoms. Surgery for an infratentorial tumor may stimulate deep brain structures, which can lead to cardiac autonomic responses. We report a brief sinus arrest immediately before dural closure following saline irrigation during removal of a cerebellar tumor. A 38-year-old female patient with no previous medical history underwent an elective surgery for resection of an infratentorial cerebellar tumor. The patient was premedicated with glycopyrrolate 0.2 mg and anesthesia was induced with propofol 80 mg and rocuronium 50 mg. Anesthesia was maintained with 50% O2 in air with 1.6-2.2% sevoflurane and infusion of remifentanil (0.1-0.15 μg/kg/min) and rocuronium (4.5-5.0 μg/kg/ min). The patient was placed in the left lateral park-bench position with the head flexed and the midline suboccipital approach was used for the surgery. The tumor was removed successfully and the dura mater was almost closed except for a 2 mm-sized window for saline irrigation. The patient’s vital signs were stable, with blood pressure 110/70 mmHg, heart rate (HR) 68 beats per min (bpm), and peripheral oxygen saturation (SpO2) 100%. The end tidal carbon dioxide partial pressure (ETCO2) was adjusted to around 32 mmHg. Normothermia was maintained at 36.0-36.2C using a forced-air patient warming system (Bair Hugger warming unit, Arizant Healthcare, MN, USA). Room temperature saline was used as an irrigation solution and 30 ml of saline was administered in a 30 ml syringe with a 17 G curved needle tip through a small window of the dura mater. Instantly, the patient developed profound bradycardia and sinus arrest. Electrocardiogram rhythm and arterial blood pressure curve showed an 8-second period of sinus arrest followed by sinus bradycardia. Immediately after being informed of the events, the surgeon stopped the irrigation. The HR returned to normal sinus rhythm (65-70 bpm) without any other treatment and the patient experienced no additional events thereafter. The patient was extubated in the intensive care unit on the following day. Her mental status recovered well and vital signs were stable.