Introduction: Airway management strategies described for complex tracheal surgery and sleeve resections include conventional ventilation via a surgically placed bronchial tube, jet ventilation via distally placed small catheters , as well as cardiopulmonary bypass and apnoeic oxygenation . This last was introduced in our hospital during the past year. The aim of this study is to describe the blood gas changes during the procedures and its haemodynamic and neurological repercussions.
Method: In the year 2005, 18 patients underwent principal airway resection surgery. Tracheal surgery was performed on 12 patients (10 subglottic) and sleeve resection on 6 patients. All patients received the TIVA technique. Cerebral activity was monitored by BIS and Somanetics® (SrO2 cerebral). In all cases the ventilation technique during the procedure was apnoeic oxygenation as follows: (1) Before sectioning the airway patients were hyperoxygenated and hyperventilated with 100% O2 for 10 minutes (hyper-oxygenation period). (2) The tracheal tube was moved to the vocal cords and a paediatric catheter was placed above the carina by the surgeon through the surgical field delivering a continuous flow of 15L O2/min (apnoeic period). 3) When the reconstruction was completed the tracheal tube was reintroduced and the patient was conventionally ventilated (postapnoeic period). Blood gases samples were taken every 15min during these 3 periods.
Results: The apnoeic period was 26 to 75 minutes (42 ± 15min). At 60min, PCO2 reached 105mmHg, the values of PO2 were 117mmHg and pH decreased to 7.05. These values were corrected in the post apnoeic period although a slight hypercapnoea remained (table below).
Table: shows the evolution in blood gases during these periods only for patients who underwent tracheal surgery (N = 12).
In the remaining 6 patients (sleeve resection), due to the complexity of surgery we occasionally needed to ventilate via a surgically placed bronchial tube for a short period in order to restore safe O2 values. No haemodynamic disturbances were found in relation to respiratory changes and no neurological problems were recorded. All patients were extubated within 2 hours of surgery.
Conclusions: In our experience apnoeic oxygenation with a small flow of oxygen through a catheter is a safe and valid anaesthetic alternative to the cross-surgical field intubation technique in such a complex surgery, improving surgical exposure.
1 Williams H, Gothard J. Jet ventilation via a Univent tube for sleeve pneumonectomy. Eur J Anaethesiol
2 Go T, Altmayer M, Richter M, et al. Decompressing manubriectomy under apneic oxygenation to release the median thoracic outlet compartment in Bechterew disease. J Thorac Cardiovasc Surg.