Ipsilateraler Pneumothorax bei Ein-Lungen-Beatmung Eine seltene, spät diagnostizierte und vermeintlich typische Komplikation bei Verwendung eines Doppellumentubus

Zusammenfassung

Die Verwendung von Doppellumentuben zur Einlungenbeatmung bei Eingriffen an der thorakalen Aorta hat die Inzidenz von Lungentraumen gesenkt und die Operationsbedingungen verbessert. Intubationsschwierigkeiten des linken Hauptbronchus, insbesondere bei großen Aortenaneurysmen, und Beatmungsprobleme infolge Dislokation während der Operation sind bekannte Verfahrensnachteile. Im vorliegenden Fallbericht wird über einen ipsilateralen Pneumothorax bei Einlungenbeatmung berichtet, dessen Diagnose und definitive Therapie verzögert wurde durch einen operationsspezifischen Blutdruck- und Sauerstoffsättigungsabfall infolge Aortenfreigabe und durch ein verfahrensspezifisches Problemlösungsverhalten (Bronchoskopie bei vermeintlicher Tubusfehllage). Eine für den Patienten kritische Hypoxämie konnte durch Beatmung der anderen Lunge verhindert werden.

Abstract

The authors report a rare, recently diagnosed and atypical mishap during one-lung ventilation (OLV) via a double lumen tube (DLT) and left-sided thoracotomy: an ipsilateral pneumothorax during ventilation of the right lung. This occurred in a 63-year-old patient with chronic obstructive airway disease who was scheduled for urgent repair of a descending thoracic aortic aneurysm. Anaesthesia and surgery were uneventful until aortic cross-clamping release. The common presentation of increased intrathoracic extrapleural pressure owing to a pneumothorax in patients with mechanically ventilated lungs is a rapid decrease in oxygen saturation, followed or paralleled by haemodynamic deterioration. Although the above presentation could be seen in this case, the diagnosis of a tension pneumothorax was delayed twice. First, symptoms were initially obscured by haemodynamic changes resulting from a head-down tilt and aortic declamping. Second, since the lack of consolidation after aortic declamping focused attention on the airway problems, complications resulting from the use of a DLT were primarily considered. In particular, since breathing sounds were detectable initially, malposition or torsion of the DLT had to be excluded by fibre-optic bronchoscopy, which involved a further delay. Finally, two observations led to the diagnosis of a right-sided tension pneumothorax: (1) bullae of the contralateral lung, detected during thoracotomy; (2) the finding that ventilation of both lungs and the left lung subsequently increased arterial (S_aO₂) and mixed venous oxygen saturation (S_vO₂) and the circulatory status, but ventilation of the right lung caused a deterioration. Chest radiography and insertion of a chest tube with drainage of air, thereafter, validated our hypothesis. The time course of oxygen desaturation during OLV and tension pneumothorax was as severe as expected; the time course of haemodynamic deterioration, however, appeared quicker and had more impact than expected. Assuming that mediastinal deviation was not hindered by contralateral intrathoracic pressure during thoracotomy, we believed that circulation should be depressed later or to a lesser extent in patients with an intraoperative pneumothorax. Yet, during thoracotomy, decrease in cardiac filling and output during tension pneumothorax in OLV obviously results primarily from the immovability of the mediastinum owing to mediastinal fixation and is at least as decisive as the contralateral intrathoracic pressure in closed-chest patients. In summary, a tension pneumothorax during one-lung ventilation and thoracotomy is a rare, but disastrous complication during the use of a DLT, which has not, to our knowledge, been reported previously. We recommend that tension pneumothorax be added to the list of complications and problems during OLV by the use of a DLT, especially in patients with structural lung diseases.