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

QUESTIONS: What 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? DESIGN: Systematic review of randomised trials with meta-analysis. PARTICIPANTS: Adults undergoing elective open cardiac surgery. INTERVENTION: The experimental groups received preoperative RMT and the comparison groups received no intervention. OUTCOME MEASURES: The 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. RESULTS: Eight 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. CONCLUSION: Preoperative 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. REGISTRATION: CRD42021227779.

Evaluation of the SenseWear activity monitor during exercise in cystic fibrosis and in health.

OBJECTIVE: Determine the SenseWear Pro3 Armband (SWA) accuracy for estimating energy expenditure (EE) and step count during treadmill walking in cystic fibrosis (CF) compared to healthy adults. HYPOTHESIS: SWA estimation of EE would be less accurate for CF, than for healthy subjects, due to interference with the SWA skin sensors caused by the high salt concentration in the sweat of CF subjects. METHODS: 17 CF (mean age 26 yr; FEV1 54% predicted) and 17 age-matched control subjects walked slightly faster than their comfortable pace on a treadmill for 20 min, whilst simultaneously wearing the SWA and breathing through an open-circuit indirect calorimetry (IC) system. Subjects' steps were manually counted. RESULTS: Combined EE data from all subjects showed no significant difference in EE measured by IC (6.0+/-3.4 kcal min(-1)) compared to the SWA estimate (6.3+/-2.5 kcal min(-1)), however the SWA significantly overestimated EE at low exercise intensities and underestimated EE at high exercise intensities. Correlations between EE values, estimated by the SWA and measured by IC, were greater than 0.85 (p<0.001) for both the CF and control group. Standard multiple regression showed that diagnosis of CF independently predicted less than 0.1% of the difference between the IC measure of EE and the SWA estimate. The SWA recorded slightly but significantly fewer steps (113+/-12 steps min(-1)) than the manual count (119+/-9 steps min(-1)). CONCLUSION: Diagnosis of CF had no significant negative impact on the accuracy of the SWA estimate of EE. The SWA provided a reasonably accurate estimate of EE and step count during treadmill walking.