Vasovagal cardiac arrest during spinal anesthesia for Cesarean section -A case report-
A 39-year-old woman, (gravida 7, para 1, [weight 67 kg, height 152 cm]) at 38 weeks of gestation, was admitted for an elective Cesarean section. She had a history of self-limited palpitation, about 3-5 times per day. This palpitation began approximately 10 years ago and usually stopped within a few seconds, without other significant symptoms. During pregnancy, she had experienced new symptoms: episodes of sudden nausea, general weakness, and dizziness after prolonged standing.\nThese symptoms were easily relieved by sitting or squatting. The preoperative blood test, urinalysis, chest X-ray, electrocardiogram (ECG), and echocardiogram were all normal. However, her 24 hour Holter monitoring revealed one episode of non-sustained ventricular tachycardia (NSVT). Five to six hours before the surgery, she felt the same self-limited palpitation, but no other symptoms were observed.\nThe patient arrived at the operating room without premedication. We started our routine monitoring with ECG, noninvasive arterial pressure, and oxygen saturation. Supplemental oxygen was administrated by a facial mask with a reservoir bag at the rate of 6 L/min. Her vital signs were a heart rate (HR) of 92-95 bpm with normal sinus rhythm, 103-104/63-64 mmHg of blood pressure (BP), and 100% of oxygen saturation (SpO2). Because she had a history of NSVT, a 20-gauge catheter was inserted, at her left radial artery, for continuous arterial pressure monitoring. After positioning the patient to the right lateral decubitus, 8 mg of 0.5% hyperbaric bupivacaine, mixed with 20 µg of fentanyl, was injected with a 25-gauge spinal needle at L4-5 interspace. Her vital signs were 92 bpm of HR, 102/63 mmHg of BP and 100% of SpO2, immediately after spinal anesthesia. Then, the patient was put in a supine position with a left lateral tilt, and was given 50 µg of prophylactic phenylephrine intravenously for the prevention of hypotension after the spinal anesthesia. The initial block level, 2 minutes after the introduction of spinal anesthesia, was at T10 checked with cold sense using an alcohol swab. As the block height went higher, the patient showed hypotension of 88/40 mmHg with 95 bpm of HR, and complained of nausea. Thus far, 700 ml of Ringer's Lactated solution had been administrated intravenously. Relative hypovolemia, caused by alpha-blocking effect of spinal anesthesia, was the suspected cause of hypotension. Therefore, we immediately injected phenylephrine twice (50 µg each), and continued hydration with hydroxyethyl starch (Voluven®, Fresenius Kabi, Germany). Her vital signs were stabilized with 96 bpm of HR and 140/74 mmHg of BP, without showing arrhythmia or reflex bradycardia, after phenylephrine administration, as well as her nausea stopped.\nSensory level to alcohol swab to the T3 was noticed, 10 minutes after the spinal anesthesia. Within 10 minutes of the skin incision, a 3.9 kg female was delivered with Apgar scores of 9 at both 1 and 5 minutes. The patient was not anxious or irritable, and showed stable vital signs. Her vital signs were 98 bpm of HR with normal sinus rhythm, 128/68 mmHg of BP, and 100% of SpO2. One gram of Cefazolin (Cefamezin®, DONG-A Pharm, Korea), mixed with 10 ml of normal saline, was administrated intravenously after a confirmation of a negative antibiotic skin test result. We suggested sedation with intravenous midazolam for the rest of the operation. However, she said she was alright and refused sedation.\nSeparation of the placenta from the uterus was not easy. Hence, a forced traction was done, repeatedly. Immediately after the placental expulsion, she suddenly looked pale and complained of severe nausea. Then she suddenly deteriorated with cardiovascular collapse, respiratory arrest, and loss of consciousness. The HR was decreased, precipitously. The QRS complex disappeared with only P-waves being observed; eventually asystole occurred. Cardio-pulmonary resuscitation (CPR) was started immediately with external cardiac compression, manual ventilation with 100% oxygen with ventilator mask, rapid hydration, and Trendelenburg position. After the injection of 1 mg of epinephrine, along with 1 minute of CPR, the ECG showed narrow QRS complexes with irregular R-R interval. However, her systolic pressure remained at 30-40 mmHg, without external cardiac compression. Approximately 3 minutes after CPR, the HR recovered up to 80-90 bpm with regular narrow QRS complex and an effective arterial pressure (80-90/70-80 mmHg). The patient gradually recovered her consciousness, spontaneous breathing, and orientation within a few minutes, and was placed horizontally with caution. Ephedrine 10 mg was administrated twice, when the systolic pressure was lower than 80 mmHg, followed by continuous infusion of dopamine at the rate of 5 µg/kg/min. The patient maintained stable vital signs and consciousness until the end of the operation. The total operation time was 80 minutes, in addition, 700 ml of Hartmann solution and 500 ml of hydroxyethyl starch (Voluven®, Fresenius Kabi, Germany) were infused. Estimated blood loss was about 500 ml and a urine output was minimal.\nAfter the operation, she was transferred to the surgical intensive care unit (SICU) for an intensive cardiovascular monitoring. The postoperative arterial blood gas analysis, complete blood count, electrolyte, and coagulation tests were normal and only serum Troponin I was mildly elevated (0.298 ng/ml). Also, the ECG and chest image showed no abnormality. Dopamine infusion was stopped, and she showed stable vital signs. After 27 hours of close observation in the SICU, she was transferred to the general ward. Postoperative cardiovascular evaluation found no abnormality, and the cardiologist recommended conservative management. After 4 days in the general ward, she was discharged without any complications. The perioperative and intraoperative vital signs are summarized in .