The Effect Of CO₂ Pneumoperitoneum On Dog Under Compound Anesthesia And Evaluation Of The Effect Of Hydrogen Intervention

The use of laparoscopic technology is beco ming more and more common in small animal clinic.When perfor ming laparoscopic surgery,most cases require the establishment of pneumoperitoneum.Currently,CO₂ is the most commonly used gas when establishing pneumoperitoneum,but this method can also have effects on the physiological function of animals in different degree.Therefore,our study purposes to analyze the effect of CO₂pneumoperitoneum on the physiological function of dogs.The method that we established is using Zoletil for induction,using isoflurane for maintenance of anesthesia and applying hydrogen for intervening the pneumoperitoneum process.We will also evaluate its protective effect on animal body,and thus make contribution to the development of laparoscopic technology and hydrogen molecular medicine in small animal clinic research.Our method takes the beagle dog as the experimental animal,dividing into control group,pneumoperitoneum group and hydrogen group.Each group has 7 dogs.All three groups use Zoletil for induction and isoflurane for maintenance of anesthesia.The control group maintains inhalation anesthesia for 90 min,doesn't establish pneumoperitoneum.Pneumoperitoneum group maintains pneumoperitoneum for 90 min with the pressure of 12 mm Hg.Hydrogen group also maintains pneumoperitoneum for 90 min with the pressure of 12 mm Hg,but inject the hydrogen at a dose of0.2 m L/kg into the subcutaneous once a day from 2 days before pneumoperitoneum to 2 days after pneumoperitoneum.Starting with the experimental dog entering a stable anesthetic state,we record its intraoperative respiratory and circulatory indicators every 15 min.We collect femoral artery blood samples at 30 min before pneumoperitoneum,45 min during pneumoperitoneum and30 min after pneumoperitoneum for blood analysis.We also collect venous blood samples before the anesthesia and at 30 min,2 h,6 h,24 h,48 h,96 h after operation respectively for the analyze of liver-kidney function and oxidative stress indicators.The clinical performance of experimental dogs are observed and recorded after surgery.The systolic blood pressure?SBP?,diastolic blood pressure?DBP?and mean arterial pressure?MAP?of the pneumoperitoneum group and the hydrogen group are higher than the control group except the initial point-in-time.The respiratory rate?RR?of the two groups is significantly higher than that of the control group from 90 min?P<0.01?.The respiratory end-tidal CO₂ pressure of the two groups is also higher than that of the control group,and the pneumoperitoneum group is significantly higher than the control group at 90 min?P<0.01?,and the hydrogen group is significantly higher than the control group at 105 min?P<0.01?.Besides,the partial CO₂ pressure?PCO₂?of the two groups is higher than that of the control group,and it is significantly higher at45 min of pneumoperitoneum process?P<0.05?.And the p H is lower than that of the control group,it is significantly lower at 45 min?P<0.01?.At 30 min after the pneumoperitoneum,the partial oxygen pressure?PO₂?and blood oxygen saturation?SO₂?are lower than that of the control group.The alanine transa minase?ALT?,aspartate transa minase?AST?,alkaline phosphatase?AKP?and total bilirubin?TBIL?of the two groups are higher than that of the control group except the initial point-in-time.And the pneumoperitoneum group is even higher than that of the hydrogen group:at 6 h after operation,the alanine transa minase?ALT?and aspartate transa minase?AST?is significantly higher?P<0.05?,also alkaline phosphatase?AKP?is significantly higher?P<0.01?.At 24 h after operation,the creatinine?CRE?of the pneumoperitoneum group is significantly higher than that of the control group?P<0.01?.And the blood urea nitrogen?BUN?is significantly higher than that of the hydrogen group?P<0.05?,and is also significantly higher than that of the control group?P<0.01?.The malondialdehyde?MDA?of the pneumoperitoneum group is higher than that of the hydrogen group and the control group except the initial point-in-time.However,the super oxide dismutase?SOD?,glutathione?GSH?and catalase of the pneumoperitoneum group are all lower than that of other two groups,and it is lower significantly at many point-in-time.The results show that under the use of Zoletil for induction and isoflurane for maintenance of anesthesia,the 12 mm Hg CO₂ pneumoperitoneum can affect the dog's respiratory system,circulatory system,acid-base balance,liver-kidney function and also cause oxidative stress,but to a small degree.The dog can be restored to normal level in a short time.We also find that the applying of hydrogen for intervening the pneumoperitoneum process can reduce the oxidative stress and liver-kidney function damage caused by CO₂ pneumoperitoneum.