Effect Of Nitroglycerin On Controlled Hypotension In General Anesthesia:A Meta-analysis Of Randomized Controlled Trials

Objective:The effect of nitroglycerin on lowering blood pressure was evaluated by meta-analysis.Methods:Cochrane,Embase,Pubmed were searched for all randomized controlled trials of nitroglycerin for controlled hypotension.The two researchers independently evaluated the quality of the included studies and extracted data.Data analysis was performed using Revman 5.3 software.Result:A total of 12 studies were included in meta-analysis.Five studies reported the average arterial pressure during the operation.The analysis results showed that the average arterial pressure in the nitroglycerin group was lower than that in the control group.The difference between the two groups was statistically significant [MD =-5.56,95% CI(-9.51,-1.60),P = 0.006];A total of 7 studies on intraoperative heart rate were recorded.The results show that the nitroglycerin group has a faster heart rate than the control group and the difference is statistically significant [MD = 14.71,95% CI(5.66,23.75),P = 0.001].There were 7 studies about the length of operation,the analysis results showed that there was no statistical difference in the data [MD =1.17,95% CI(-4.29,6.63),P = 0.67];Four studies scored the situation of the surgicalfield,and the analysis results showed that there was no difference in surgical field clarity between the two groups,and it was not statistically significant [MD = 0.36,95% CI(-1.05,1.77),P = 0.61];Two studies recorded the time from the beginning of hypotension to the target blood pressure in the controlled hypotension operation,the results showed that the time for nitroglycerin group to reach the target blood pressure was longer than that for other antihypertensive drugs.The difference between the two groups was statistically significant [MD = 1.38,95% CI(0.41,2.35),P = 0.005];Two studies reported data on carbon dioxide at the end of respiration,the results showed that the value of nitroglycerin group was higher than that of control group.The difference between the two groups was statistically significant [MD = 1.86,95% CI(0.88,3.65),P = 0.04];Seven studies reported the blood loss during the operation.The meta-analysis showed that there was no significant difference in blood loss between the two groups [MD = 1.16,95% CI(-45.89,48.21),P = 0.96].Conclusion:According to the comprehensive consideration of each monitoring index,there was no significant difference between nitroglycerin and other antihypertensive drugs in operation duration,operation field score,blood loss during controlled hypotension under general anesthesia.Compared with other antihypertensive drugs,nitroglycerin has a lower mean arterial pressure during operation and a faster heart rate.