This study is important because it shows for the first time that the SPV does not change significantly in the prone position, and may therefore continue to be used as an indicator of the volume status. It also would appear to indicate that our methods for protecting the chest and abdomen in the prone position are effective.

A 50-year-old man with carcinoma of the trachea presented for debulking. Due to the distal location of the tumor, a tracheostomy was not feasible. We were asked to provide general anesthesia but to maintain spontaneous ventilation. Sedation was provided with dexmedetomidine 0.7 μg/kg per hour. Following induction with ketamine 2 mg/kg, the trachea was sprayed with 5 ml of 4% lidocaine and, with assistance from the surgeon, a Cook™ Airway Exchange catheter was placed with the distal end just beyond the tumor. We then connected the proximal end to a manual jet ventilator to provide oxygen supplementation and, if necessary, positive-pressure ventilation. Subsequently, the surgeons were able to completely debulk the tumor and examine the airway down to the carina. Spontaneous ventilation was maintained throughout the case, with additional boluses of ketamine as necessary. The patient woke up after the procedure and had no delirium, nightmares, or recall. Dexmedetomidine worked synergistically with ketamine by preventing hypertension, hypersecretion, and postoperative delirium that is often seen when using ketamine alone. The successful use of ketamine and dexmedetomidine in this case demonstrates that this method may be applicable to other clinical situations where deep sedation and maintenance of spontaneous ventilation is required.

Autoregulation of cerebral blood flow remains preserved after mild hypothermic CPB.

No abstract