A 77-year-old male presented to the department of neurosurgery with prolonged numbness and weakness in the limbs. Investigation revealed compression of the spinal cord by a herniated pulposus, and a cervical laminoplasty from the 3rd to 6th cervical vertebra was scheduled. The medical history included hypertension, diabetes, and a coronary artery bypass graft due to acute myocardial infarction 8 years prior. There was no history of allergy.
Premedication was not used. Theatre monitoring included noninvasive blood pressure measurement, electrocardiography, pulse oximetry, and end-tidal carbon dioxide concentration (E
TCO
2) measurement. The vital signs before anesthesia were: a blood pressure (BP) of 161/78 mmHg, regular sinus rhythm with a heart rate (HR) of 50 beat/min and a peripheral oxygen saturation (SpO
2) of 99%. Anesthesia was induced using lidocaine 40 mg, propofol 120 mg, and vecuronium 10 mg. After conducting mask ventilation for 3 minutes with O
2 4 L/min, N
2O 4 L/min, and sevoflurane 6 vol%, the trachea was intubated with an 8.0-mm armored endotracheal tube. Anesthesia was maintained using O
2 1 L/min and N
2O 1 L/min, and sevoflurane 1.5-2.5 vol%. The vital signs remained stable after intubation. Mechanical ventilation was performed with minute ventilation of 5.5 L/min, E
TCO
2 of 28-30 mmHg, and a PIP of 18 cmH
2O. Subsequently, vecuronium 4 mg/hr was infused for continuous muscle relaxation. The patient was shifted to the prone position for the operation, and the PIP was 20 cmH
2O at that stage. Twenty minutes after anesthesia induction, cefuroxime sodium 1.5 g was administered as a prophylactic antibiotic without any previous allergic tests. Five minutes later, the PIP suddenly increased to 33 cmH
2O, E
TCO
2 slightly increased to 35 mmHg, and SpO
2 dropped to 94% and then recovered and was maintained at 97-100%. The endotracheal tube was suctioned, but there was no evidence of a large amount of secretion. Ventilation impairment worsened, and PIP increased to 40 cmH
2O, BP dropped to 66/28 mmHg and HR to 35 beats/min. We immediately converted to ambu bag manual ventilation, however severe resistance was experienced. Auscultation was difficult due to the surgical position and the operation field. Best possible use of a esophageal stethoscope revealed low breathing sounds. N
2O administration was immediately ceased, and 100% O
2 6 L/min was administered. Suspecting that an anaphylactic reaction had occurred, hydrocortisone 100 mg and vecuronium 3 mg were injected for suspected bronchial spasm. However, ventilation did not improve. Atropine 0.5 mg and epinephrine 10 µg were injected, and a dopamine 10 µg/kg/min infusion was commenced to maintain BP. However, BP decreased to 56/22 mmHg and HR to 30 beat/min. Arterial blood gas analysis (ABGA) showed a pH of 7.03, PaCO
2 of 88 mmHg, PaO
2 of 345 mmHg, and SaO
2 of 100% (
Table 1). Epinephrine 30 µg was administered under continuous infusion at 0.05 µg/kg/min. Chest radiography was then considered essential to determine whether there was a mechanical problem or pulmonary complication. However, this was difficult due to the iron frame of the operating table. Moreover, the patient was undergoing cervical spine surgery in a fixed prone position, and if cardiac arrest eventuated, it would have been very difficult to perform cardiopulmonary resuscitation (CPR). Therefore, the surgery was abandoned and the surgical wound promptly closed. Ventilation did not improve and breathing was scarcely heard during wound closure. The patient was placed in the supine position and chest radiography performed. Cardiac arrest occurred. Atropine 1 mg and epinephrine 1 mg were immediately injected twice while chest compression was conducted for 10 minutes. Subsequently, BP increased to 110/43 mmHg and HR to 48 beat/min. SpO
2 decreased to 70% and ABGA showed a pH of 6.97, PaCO
2 of 115 mmHg, and PaO
2 of 30 mmHg. The chest radiograph revealed tension pneumothorax in both lungs (
Fig. 1B). Needle aspiration was immediately performed, followed by the insertion of chest tubes into the thoracic cavity. Following tube insertion, ventilation improved and PIP decreased to 28 cmH
2O. ABGA showed a pH of 7.32, PaCO
2 of 51 mmHg, PaO
2 of 399 mmHg, and SaO
2 of 100%. The vital signs normalized, BP was 135/54 mmHg, and HR was 52 beat/min. The patient was transferred to the intensive care unit with intubation.