Abstract: Objective To evaluate the effect of threshold inspiratory muscle training (TIMT) on respiratory muscle strength and clinical outcomes for machinery ventilates patients. Methods The Cochrane Library, PubMed, Embase, Web of Science, CBM, Wanfang Database, CNKI and VIP were searched for the randomized controlled trials (RCT) about the effect of TIMT on respiratory muscle strength and clinical outcomes from establishment to July 1st, 2018. Two researchers strictly evaluated literature quality and extracted information, and then a Meta-analysis was carried out. Results A total of 14 literatures were included with 650 patients, 323 cases in the experimental group and 327 cases in the control group. Compared with the control group, the massive inspiratory pressure (MIP) increased (MD = -6.65, 95%CI -8.27~-5.03, P < 0.001), the respiratory muscle strength increased (MD = -5.04, 95%CI -7.68~-2.04, P = 0.0002), the weaning time reduced (MD = -1.01, 95%CI -1.65~-0.37, P = 0.002), the mechanical ventilation time shortened (MD= -2.24, 95%CI -4.33~-0.15, P = 0.04), as well as the intensive care unit (ICU) length of stay (MD= -3.41, 95%CI -6.06~-0.76, P= 0.01). There was no significant difference in maximum expiratory pressure (MEP) (MD= 1.22, 95%CI -6.55~9.00, P = 0.76), the rate of reintubation/tracheotomy (RR = 0.99, 95%CI 0.56~1.73, P = 0.96) and mortality (RR= 1.05, 95%CI 0.53~2.06, P = 0.89) between two groups. Conclusion TIMP could improve MIP and respiratory muscle strength of patients with mechanical ventilation, shorten the weaning time, the mechanical ventilation time and the ICU length of stay, and then reduce the incidence of weaning failure.

Key words: threshold inspiratory muscle training, mechanical ventilation, weaning, respiratory muscle strength, meta-analysis