Maharjan S K, Shrestha B R
Department of Anaesthesiology and Intensive care, Kathmandu Medical College Teaching Hospital, Sinamangal, Kathmandu.
Kathmandu Univ Med J (KUMJ). 2007 Jul-Sep;5(3):307-11.
The purpose of this study was to assess the effects of hyperventilation on patients undergoing laparoscopic surgeries on haemodynamics, partial pressure of carbon dioxide and acid base status.
60 patients undergoing laparoscopic surgeries under General Anaesthesia were randomized into two groups, "control group" ventilated with tidal volume of 10 ml/kg and respiratory rate of 12/minute and "study group" same tidal volume with respiratory rate of 15/ minute. Hemodynamic variables (heart rate and mean arterial pressure) recorded and End tidal C02, PaC02, pH and Bicarbonate estimation done before, during and after C02 pneumoperitoneum and analyzed.
There was no significant difference in hemodynamic variables but there was linear increase in ETC02 and PaC02 measurements in higher normal levels in control group (ETC02 33.3+/-3.20, 37.93+/-3.95 and 43.20+/-3.40; PaC02 30.08+/-2.35, 34.80+/-4.01 and 41.94+/-3.66 mmHg before, during, and after pneumoperitoneum respectively) compared to study group in which these parameters were in lower normal levels (ETC02 33.33+/-4.11, 28.00+/-4.10 and 36.73+/-2.49 mmHg and PaC02 31.80+/-2.73, 29.36+/-3.16 and 35.15+/-1.32 mmHg before, during, and after pneumoperitoneum respectively). There was highly significant difference in these parameters when intergroup comparison was done during and after pneumoperitoneum period. pH and bicarbonate levels were within normal limits but there was decreasing tendency towards acidosis side in control group.
10-15% increment in Minute Volume is beneficial during C02 pneumoperitoneum to prevent adverse effects of hypercarbia and acidosis.
本研究旨在评估过度通气对接受腹腔镜手术患者的血流动力学、二氧化碳分压和酸碱状态的影响。
60例在全身麻醉下接受腹腔镜手术的患者被随机分为两组，“对照组”采用潮气量10 ml/kg、呼吸频率12次/分钟进行通气，“研究组”采用相同潮气量、呼吸频率15次/分钟进行通气。记录血流动力学变量（心率和平均动脉压），并在二氧化碳气腹前、气腹期间和气腹后进行呼气末二氧化碳、动脉血二氧化碳分压、pH值和碳酸氢盐测定并分析。
血流动力学变量无显著差异，但对照组较高正常水平的呼气末二氧化碳和动脉血二氧化碳分压测量值呈线性增加（呼气末二氧化碳分别为气腹前33.3±3.20、气腹期间37.93±3.95、气腹后43.20±3.40；动脉血二氧化碳分压分别为气腹前30.08±2.35、气腹期间34.80±4.01、气腹后41.94±3.66 mmHg），而研究组这些参数处于较低正常水平（呼气末二氧化碳分别为气腹前33.33±4.11、气腹期间28.00±4.10、气腹后36.73±2.49 mmHg；动脉血二氧化碳分压分别为气腹前31.80±2.73、气腹期间29.36±3.16、气腹后35.15±1.32 mmHg）。在气腹期间和气腹后进行组间比较时，这些参数存在高度显著差异。pH值和碳酸氢盐水平在正常范围内，但对照组有向酸中毒方向降低的趋势。
在二氧化碳气腹期间，分钟通气量增加10 - 15%有利于预防高碳酸血症和酸中毒的不良反应。
