Apneic oxygenation in thoracic surgery in patients with previous pneumonectomy

Abstract

Introduction Anaesthetic management of patients undergoing thoracic surgical procedures for lung cancer poses unique challenges to the anaesthesiologist, including patients’ comorbidities, lateral decubitus position, the need for lung isolation, and the associated pathophysiology during and after these procedures. Anaesthetic management is even more challenging in patients with previous pneumonectomy. In this case report we present two patients, who had a previous history of left pneumonectomy and were scheduled for surgical resection of a tumor in the remaining right lung. Methods Apneic oxygenation was used in both patients (patients A and B) intraoperatively, initially by oxygen insufflation via a thin catheter advanced to the level of the carina through a single lumen endotracheal tube. After the development of hypoxemia apneic oxygenation was continued via a Mapleson C circuit. Results For a significant period of time, oxygenation was preserved in both patients. Patients A and B showed time to oxygen desaturation of 30min and 25min respectively. Hypoxemia was recognized immediately by SpO2 decline below 90% and was confirmed via blood gas samples. Apneic oxygenation via a Mapleson C circuit was applied successfully for hypoxemia management in both patients. Oxygen levels improved immediately and remained stable until the end of apneic oxygenation. Total duration of apneic oxygenation was 90min and 50min in patients A and B, respectively. Increase of arterial carbon dioxide tension (PaCO2) and subsequent respiratory acidosis were predictable results of apneic oxygenation that were corrected quickly by mechanical ventilation (MV). After the end of surgery, both patients were admitted intubated to the ICU, where weaning from MV was successful after 2hrs. Patients A and B were discharged from the ICU on first postoperative day after an uncomplicated postoperative course. Discussion Apneic oxygenation is an acceptable oxygenation technique during thoracic surgery, especially in patients with previous pneumonectomy, which is able to keep sufficient oxygenation for a significant period of time, and does not deserve any special equipment. The expected hypercapnia and respiratory acidosis limit the duration of its application. PaCO2 values are related with the total time of apneic oxygenation and the only effective way for its decrease is mechanical ventilation. In the absence of pulmonary hypertension or pathology of the brain, mechanical ventilation normalises PaCO2 and pH quickly, without any complications.