Capnothorax: implications for the anaesthetist

Ten patients underwent a laparoscopic surgical technique for thoracic and cervical dissection of the oesophagus during oesophagogastrectomy. Thoracotomy was avoided with potential benefits to the patient. To facilitate surgical access the right lung was collapsed using a double-lumen bronchial tube and carbon dioxide was insufflated into the right pleural cavity to compress the lung. Changes in haemodynamic and respiratory variables occurred. In the majority of the patients airway pressure and end-tidal CO2 increased, despite alterations in ventilation. In five patients systolic blood pressure decreased suddenly by between 15 and 35 mmHg, and in four patients SpO2 decreased to 91% or less, despite an FIO2 of 1.0. If carbon dioxide was insufflated too fast, or the lung failed to deflate adequately, the clinical picture was that of a tension pneumothorax. One patient developed surgical emphysema and a contralateral pneumothorax. Postoperatively two patients had recurrent laryngeal nerve damage. Suggestions are made to minimise the changes in haemodynamic and respiratory variables during carbon dioxide insufflation into the thorax.