Effects of Subcutaneous CO_2 Insufflation on Cardiovascular and Arterial Blood Gases during Endoscopic Thyroid Operations

Objective To observe the effects of subcutaneous carbon dioxide insufflation on cardiovascular and arterial blood gases during endoscopic thyroid operations.Methods Thirty-one patients scheduled for endoscopic thyroid operations under general anesthesia with endotracheal intubation.The pressure of CO2 insufflation was set at 5～7mmHg.The HR,SBP,DBP,MAP,arterial pH value and PaCO2 were monitored.Results The HR and BP were increased rapidly after the insufflation.The MAP reach the peak 45min after the insufflation((96.50±12.6)mmHg).The arterial PaCO2 began to increase and the pH value decrease 15 min after the insufflation.The PaCO2 reached the peak((43.63±2.42)mmHg) 30min and the pH value fell to the lowest(7.33±0.04) 45min after the insufflation.The HR,BP,PaCO2 and pH value after the insufflation showed significant difference as compared with the indexs before the insufflation(P0.05).The arterial PaCO2 began to decrease and the pH value went up 45 min after the insufflation and they reached at stable levels 60 min after the insufflation.After the deflation,the PaCO2 and pH value went to the levels before the insufflation.Conclusion Subcutaneous carbon dioxide insufflation has excited the cardiovascular and caused CO2 accummulation.The pressure of CO2 insufflation was set at 5～7mmHg effects on the arterial PaCO2 and pH value during endoscopic thyroid operations,but these effects are still within the normal ranges.