A Case of Hypoxemia Occurred During One-Lung Ventilation

Background: In thoracic surgery, One Lung Ventilation (OLV) is a common technique to maintain ventilation and oxygenation. Hypoxemia during OLV is not rare, and if not detected in time or handled improperly, it may cause serious consequences and threaten the life of the patient. In the perioperative period, various factors including surgery, anesthesia and patients themselves may lead to the occurrence of hypoxemia during OLV. How to prevent and reduce the occurrence of hypoxemia in patients with OLV is a concern of anesthesiologists during the perioperative period. Methods: A case report study with analysis. Results: We report a case of hypoxemia during OLV in an elderly patient who underwent videoassisted thoracoscopic wedge resection of a mass in the left upper lung plus lymphatic dissection, which was successfully corrected by associated anesthesia management measures. Conclusion: Hypoxemia during one-lung ventilation is not uncommon. For patients requiring one-lung ventilation during the operation, the anesthesiologist shall fully evaluate the patient's condition, and formulate a reasonable anesthesia plan according to some predictors of hypoxemia, so as to prevent or reduce the incidence of hypoxemia during one-lung ventilation and ensure the safety of the patient's life. Qian Liu#, Yu Zhou#, Xiaoyu Wang and Xiaoping Gu* Department of Anesthesiology, The Affiliated Hospital of Nanjing University Medical School, China #These authors contributed equally to this work and should be considered as co-authors Annals of Clinical Case Reports Anesthesiology Remedy Publications LLC. , | http://anncaserep.com/ 2020 | Volume 5 | Article 1826 2 Xiaoping Gu, et al., rate. Echocardiography showed enlargement of the left and right atrium, thickening of the base of the ventricular septum, moderate tricuspid and mitral regurgitation, calcification of the aortic valve, mild pulmonary hypertension (about 36 mmHg), and an EF value of 61%. The pulmonary function was low at the maximum volume, F-V curve showed limited airflow in small airway, and moderate mixed ventilation dysfunction. The dynamic electrocardiogram showed sustained atrial fibrillation, with the longest R-R interval of 2.16s, a total of 67 ventricular premature beats, and intermittent T-wave depression. He was accepted in ASA grade-III for surgery. When entering the operating room, there was ABP of 124~146/86~92 mmHg, heart rate of atrial fibrillation, pulse oxygen saturation (SpO2) of 100% under pure oxygen condition. Midazolam was given 6 mg, vecuronium 12 mg, fentanyl 0.75 mg and etomidate 20 mg for general anesthesia induction. After 5 min, right-sided DLT (35Fr) was inserted with good ventilation. The fiberoptic bronchoscopy confirmed good positioning of the catheter, with machine-controlled breathing, Respiratory Rate (RR) 12 times / min, oxygen flow rate 2 L/min, and double-lung ventilation. Before surgery, the body position changed from supine to right lateral position, the main tube was well aligned by fiberoptic bronchoscopy, and Arterial Blood Gas (ABG) analysis was performed at pH 7.40, PaCO2 41 mmHg, PaO2 231 mmHg, SpO2 100%. At the beginning of the operation, right lung ventilation was given, with Tidal Volume (VT) 350 ml, RR 14 times/min, and airway pressure of 25 mmHg. Intravenous infusion of 2% propofol 20 mL/h, vecuronium 3 mg/h, remifentanil 0.5 mg/h, sevoflurane 1% intermittent inhalation to maintain general anesthesia. The BP fluctuated between 88~120/57~70 mmHg. When the SBP was lower than 90 mmHg, sevoflurane was stopped, and phenylephrine was given 80 ug intravenous injection. Meanwhile, propofol was reduced to 16 mL/h and remifentanil was 0.3 mg/h, and the blood pressure rose to normal. SpO2 remains at 96% to 98%. At about 40 min of OLV, SpO2 of the patient decreased slowly from 96% to 86%, BP fluctuated between 92~100/55~62 mmHg, and P peak was 29 mmHg. The anesthesiologist immediately used a fiberoptic bronchoscopy to confirm that the catheter was in place and artificially controlled breathing. SpO2 then rose, to about 90%. VT was increased to 450 ml and ventilation was controlled by ventilator. ABG analysis showed pH 7.38, PaCO2 44 mmHg, PaO2 56 mmHg, SpO2 88%. The patient's PaO2 was less than 60 mmHg, and the anesthesiologist considered the patient to have hypoxemia. The patient was given short-term two-lung ventilation and then singlelung ventilation, followed by light anesthesia, discontinuation of inhaled anesthetics, reduction of propofol to 12 mL/h, remifentanil 0.15 mg/h, intermittent intravenous injection of phenylephrine 100 ug to maintain the BP at 120~140/70~80 mmHg, and the patient's SpO2 eventually rose to 100%. After surgical removal of the diseased lung, bilateral ventilation was performed. After the operation, the double lumens were changed into a single tube. The operation lasted for 1 h and 35 min, with 20 mL of bleeding, 300 mL of urine, 1500 mL of infusion including 500 mL of crystal fluid and 1000 mL of colloidal fluid. After the operation, the patient's vital signs were stable, and the ABG analysis was normal.