Role Of Impedance Threshold Device In The Quality Of Cardiopulmonary Resuscitation:A Meta Analysis

Objective:To assess the effect on quality and prognosis of ITD in CPR.Methods:My partners and I reviewed clinical research about comparing using active ITD with using sham ITD in persons who recieve CPR in multiple data-base(ISI WOK,Pub Med, Sino MED,Wanfang Date,CNKI); English keywords “impedance threshold device, ITD,inspiratory impedance threshold device,inspiratory threshold valve,ITV,inspiratory resistance valve,cardiopulmonary resuscitation,CPR,active compression decompression cardiopulmonary resuscitation,ACD-CPR” were included. After screening and assessing the quality of the data, we including research with the inclusion criteria.The accepting criteria:(1) RCTs or prospective studies were selected.(2) People of disease must be those who were adult and contracted the cardiac arrest.(3) Intervention: In ITD group, the studies had combined ITD with ACD-CPR or S-CPR. In control group, the studies had used ACD-CPR or S-CPR alone.(4) Observation indexes:(1)The numbers of return of spontaneous circulation(ROSC).(2)The neurologic outcome(modified Rankin score ≤3).(3)The numbers of hospital discharge. The exclusion criteria:(1) Retrospective study or case report.(2) Animal experiment.(3) Duplication, study with incomplete data. Two independent authors estimated the quality of the studies with Modified jadad score: randomized or not; randomization was narrated or not; the method of randomization was proper or not; concealment of allocation was noted or not; the method of concealment of allocation was proper or not; double-blind experiment or not; random double-blind method was described or not; random double-blind methodwas proper or not; exit and losing to follow-up werereferred to or not. Whenwehad different views, two authors got conclusion after discussion; Two of the all authors extracted study data whichinclude: published date,authors, journal name, basic disease, sex ratio, the numbers of return of spontaneous circulation, the neurologic outcome(modified Rankin score ≤3), the numbers of hospital discharge on their own; Rev Man 5.3 software were used for data analysis. Continuous variables data were represented with mean difference(MD), 95% CI; Eenumeration data were represented with odds ratio(OR), 95% CI; Heterogeneity testing of the results: there were no significant heterogeneity, and the fixed effect model was used when I2<50%, while there were marked heterogeneity and when I2>50% we would use the random effects model.Then we discussed the existence of bias in publication according to the funnel plot. If the funnel plot was asymmetrical, we thought the bias in publication was existent.Results:Eight studies of cardiac arrest were included with 138992 patients. Comparing with the sham ITD group, ITD did not impact on the rate of ROSC[OR=1.03, 95%CI(0.96,1.11),P=0.35],but improve the neurologic outcome [OR=1.74, 95%CI(1.11,2.73),P=0.02]and the rate of hospital discharge[OR=1.40, 95%CI(1.04,1.91),P=0.03].The subgroup analysis implicated combined use of ITD with ACD-CPR increased the rate of ROSC[OR=1.13, 95%CI(1.01,1.26),P=0.03],the neurologic outcome[OR=1.53, 95%CI(1.22,1.93),P=0.0002] and the rate of hospital discharge[OR=1.25, 95%CI(1.04,1.49),P=0.02].Conclusion:ITD did not impact on the rate of ROSC but it improve the neurologic outcome and the rate of hospital discharge. However the subgroup analysis showed that combined use of ITD with ACD-CPR increased the rate of ROSC and the rate of hospital discharge, and improved the neurologic outcome.