Atrial Fibrillation Complicating Left Pneumothorax After Malpositioning of a Double-Lumen Tube

Abstract

A 66-year-old woman (weight 133.3 lbs, height 158 cm) was scheduled for atrial septal defect (ASD) repair through a thoracotomy. Preoperative chest radiography was normal, and an electrocardiogram showed an incomplete right bundle-branch block. Transesophageal echocardiography revealed moderate right atrium and ventricle dilation, a pulmonary arterial pressure of 52 mmHg, and an ASD-associated left-to-right shunt. In the operating room, her blood pressure was 125/75 mmHg, her heart rate was 94 beats/min, and the SpO2 was 97% on room air. The patient was intubated with a 35F left-sided double-lumen tube (DLT) under direct laryngoscopy to a depth of 31 cm at the incisors. The DLT placement was checked by auscultation. During manual ventilation, increased airway resistance was noted, and no breath sounds were heard over either lung fields. The tube was pulled back 2 cm, and bilateral breath sounds were again documented. The end-tidal carbon dioxide waveform was present on the monitor. At that time, rapid-rate atrial fibrillation of 130 beats/min occurred with a blood pressure of 63/40 mmHg. Phenylephrine boluses were given to maintain hemodynamic stability. Correct positioning of the DLT was confirmed by fiberoptic bronchoscopy. Meanwhile, SpO2 remained within the normal range. Soon thereafter, a median sternotomy was performed instead of a thoracotomy, and a left pneumothorax was diagnosed and released by pleural opening. This was followed by rapid conversion of the atrial fibrillation into sinus rhythm and restoration of normal blood pressure. During one-lung ventilation, barotrauma from excessive tidal volume and high airway pressure may occur if a left-sided DLT is positioned distally such that the entire tidal volume is directed to only one lobe.1Silvalingam P. Tio R. Tension pneumothorax, pneumomediastinum, pneumoperitoneum, and subcutaneous emphysema in a 15-year-old Chinese girl after a double-lumen tube intubation and one-lung ventilation.J Cardiothorac Vasc Anesth. 1999; 13: 312-315Abstract Full Text PDF PubMed Scopus (34) Google Scholar, 2Malik S. Shapiro W.A. Jablons D. et al.Contralateral tension pneumothorax during one-lung ventilation for lobectomy: Diagnosis aided by fiberoptic bronchoscopy.Anesth Analg. 2002; 95: 570-572PubMed Google Scholar In our patient, high peak airway pressure may have been generated during manual ventilation to check the DLT position, which was placed too distal. The average depth of insertion for patients 170 cm tall was 29 cm, and for each 10-cm increase or decrease in height, the average placement depth was increased or decreased 1 cm.3Brodsky J.B. Benumof J.L. Ehrenwerth J. et al.Depth of placement of left double-lumen endobronchial tubes.Anesth Analg. 1991; 73: 570-572Crossref PubMed Scopus (95) Google Scholar A pneumothorax presents as increased airway pressure, decreased tidal volume, decreased SpO, and hypotension. Sudden-onset atrial fibrillation may occur for a variety of reasons during anesthesia. Our patient developed rapid-rate atrial fibrillation with hypotension, probably as a complication of the pneumothorax, which was diagnosed only after sternotomy. Had we initiated one-lung ventilation, cardiovascular collapse would have developed. Previous reports showed that a pneumothorax may be associated with numerous electrocardiographic changes.4Price J.W. Novel electrocardiographic changes associated with iatrogenic pneumothorax.Am J Crit Care. 2006; 15: 415-419PubMed Google Scholar, 5Strizik B. Forman R. New ECG changes associated with a tension pneumothorax.Chest. 1999; 115: 1742-1744Crossref PubMed Scopus (37) Google Scholar The sudden rise in intrathoracic pressure and rotation around the longitudinal axis of the heart has been suggested as a cause of these changes. A proposed mechanism for PR-segment changes is atrial ischemia caused by compression of air on the collapsed lung and subsequently on the heart. In our patient, a shift in heart position secondary to the pneumothorax in addition to the atrial enlargement may have predisposed to this mechanical irritation and subsequent atrial fibrillation. In conclusion, we report a case of atrial fibrillation complicating a left pneumothorax that was caused by barotrauma after malpositioning of a DLT in the presence of an ASD. Atrial fibrillation was reverted by releasing the pneumothorax. The diagnosis of a pneumothorax should be considered during DLT insertion whenever a patient develops cardiovascular instability.