Preoperative respiratory muscle training reduces the risk of pulmonary complications and the length of hospital stay after cardiac surgery: a systematic review

Abstract

QuestionsWhat is the effect of preoperative respiratory muscle training (RMT) on the incidence of postoperative pulmonary complications (PPCs) after open cardiac surgery? What is the effect of RMT on the duration of mechanical ventilation, postoperative length of stay and respiratory muscle strength? DesignSystematic review of randomised trials with meta-analysis. ParticipantsAdults undergoing elective open cardiac surgery. InterventionThe experimental groups received preoperative RMT and the comparison groups received no intervention. Outcome measuresThe primary outcomes were PPCs, length of hospital stay, respiratory muscle strength, oxygenation and duration of mechanical ventilation. The methodological quality of studies was assessed using the PEDro scale and the overall certainty of the evidence was assessed using the GRADE approach. ResultsEight trials involving 696 participants were included. Compared with the control group, the respiratory training group had fewer PPCs (RR 0.51, 95% CI 0.38 to 0.70), less pneumonia (RR 0.44, 95% CI 0.25 to 0.78), shorter hospital stay (MD −1.7 days, 95% CI −2.4 to −1.1) and higher maximal inspiratory pressure values at the end of the training protocol (MD 12 cmH2O, 95% CI 8 to 16). The mechanical ventilation time was similar in both groups. The quality of evidence was high for pneumonia, length of hospital stay and maximal inspiratory pressure. ConclusionPreoperative RMT reduced the risk of PPCs and pneumonia after cardiac surgery. The training also improved the maximal inspiratory pressure and reduced hospital stay. The effects on PPCs were large enough to warrant use of RMT in this population. RegistrationCRD42021227779