The effect of cervical gas insufflation on intracranial pressure during endoscopic neck surgery

OBJECTIVE Carbon dioxide and helium were insufflated into the neck of rabbit to investigate the effect of different levels of insufflation pressure and duration on intracranial pressure. METHODS Fifteen New Zealand rabbits were randomly divided into 5 groups: 5 mmHg CO2, 10 mmHg CO2, 15 mmHg CO2, 15 mmHg He and 0 mmHg group. Arterial partial pressure of CO2 (PaCO2), pH and intracranial pressure (ICP) were measured at baseline, 45 min and 90 min after gas insufflation and 30 min after desufflation. RESULTS Insufflation of CO2 at 5mmHg did not have any significant effect on the parameters. PaCO2 increased significantly 45 min and 90 min after CO2 insufflation at 10mmHg (P0.05). Marked changes in PaCO2, pH and ICP occurred 45 min and 90 min after CO2 insufflation at 15mmHg (P0.05), and the parameters did not return to baseline 30 min after desufflation. In animals receiving He insufflation at 15mmHg, ICP elevated significantly after 45 min and 90 min (P0.05), and returned to baseline 30 min after desufflation. Animals receiving He insufflation did not experience hypercapnia. CONCLUSION Intracranial pressure cannot be influenced by carbon dioxide and Helium insufflation for endoscopic neck surgery below 10mmHg.