LOSS OF HYPOXIC VENTILATORY RESPONSE FOLLOWING BILATERAL NECK DISSECTION

Modified radical neck or combined radical and modified radical neck su rgery is performed for treatment of head and neck cancer. Because of t he extensive nature of the surgery, including dissection around the ca rotid vessels, we prospectively evaluated hypoxic ventilatory response s preoperatively and postoperatively in five patients. The change in v entilation to percent desaturation varied between -0.22 and -0.60 L/mi n per percent desaturation in the five study patients. In the postoper ative evaluation, two of the five patients showed flattened responses compared with the preoperative measurements due to denervation of thei r carotid bodies. Two patients showed increased responses due to loss of upper airway resistance from tracheostomy. We conclude that after b ilateral neck dissection for cancer surgery some patients may lose the ir hypoxic ventilatory responses due to carotid body denervation.