Respiratory muscle strength is not decreased in patients undergoing cardiac surgery

Functional Physical Analysis and Quality of Life in the Preoperative and Early Postoperative Periods of Cardiac Surgery and 30 Days After Hospital Discharge

INTRODUCTION

The analysis of patients submitted to heart surgery at three assessment times has been insufficiently described in the literature.

OBJECTIVE

To analyze chest expansion, maximum inspiratory pressure (MIP), maximum expiratory pressure (MEP), distance traveled on the six-minute walk test (6MWT), and quality of life in the preoperative period, fourth postoperative day (4th PO), and 30th day after hospital discharge (30th-day HD) in individuals submitted to elective heart surgery.

METHODS

A descriptive, analytical, cross-sectional study was conducted with 15 individuals submitted to elective heart surgery between 2016 and 2020 who did not undergo any type of physiotherapeutic intervention in Phase II of cardiac rehabilitation. The outcome variables were difference in chest expansion (axillary, nipple, and xiphoid), MIP, MEP, distance on 6MWT, and quality of life. The assessment times were preoperative period, 4th PO, and 30th-day HD.

RESULTS

Chest expansion diminished between the preoperative period and 4th PO, followed by an increase at 30th-day HD. MIP, MEP, and distance traveled on the 6MWT diminished between the preoperative period and 4th PO, with a return to preoperative values at 30th-day HD. General quality of life improved between the preoperative period and 4th PO and 30th-day HD. An improvement was found in the social domain between the preoperative period and the 30th-day HD.

CONCLUSION

Heart surgery causes immediate physical deficit, but physical functioning can be recovered 30 days after hospital discharge, resulting in an improvement in quality of life one month after surgery.

Effects of high-intensity inspiratory muscle training on systemic inflammatory response in cardiac surgery - A randomized clinical trial

PURPOSE

Preoperative inspiratory muscle training reduces the incidence of postoperative pulmonary complications after cardiac surgery, but training protocols vary widely in terms of intensity. Currently, the mechanisms underlying the effectiveness of this practice are not known. The purpose of the present study is to determine whether preoperative high-intensity inspiratory muscle training (HI-IMT) modulates the perioperative systemic inflammatory response in cardiac surgery patients.

METHODS

Participants awaiting surgical aortic valve replacement were randomized to 3 to 6 weeks preoperative home-based HI-IMT or same duration low-intensity inspiratory muscle training (LI-IMT). The primary outcome was the preoperative value of the soluble tumor necrosis factor receptor 1 (sTNFR1). Secondary outcomes assessed perioperative evolution of the cytokines: sTNFR1, Tumor necrosis factor-α, Interleukin (IL)-6, IL-8, IL10, IL1β, and their combined z-score; reflecting post-training and postoperative inflammatory response. Perioperative pulmonary function and postoperative clinical outcomes were collected.

RESULTS

Between February 2018 and March 30, 2019 patients were randomized, to HI-IMT or LI-IMT. There were no differences between the groups in terms of baseline characteristics. The median (IQR) training duration was 34 (28-44) days. After training, the median (IQR) predicted maximal inspiratory pressure was higher in the HI-IMT vs LI-IMT group (119 (96-142%) vs 97 (81-107%); p = .04) Levels of the sTNFR1 cytokine increased during training in the HI-IMT group, pre vs post training (Median (IQR) 1073 (920; 1219) vs 1172 (965; 1368) ng/L; p = .03). The 24-h postoperative global inflammatory score was lower in the HI-IMT than in the LI-IMT group (Median (IQR), -0.37 (-0.62, 0.03) vs -0.10 (-0.17, 0.49), p = .04). Global inflammatory scores were not different at other time points. There were no significant differences between the groups in post-operative pulmonary function and postoperative clinical outcome.

CONCLUSION

High intensity inspiratory muscle training shows immunomodulatory properties. These properties could explain why preoperative inspiratory muscle training can lead to lung protection after cardiac surgery.

Efficacy of Respiratory Muscle Training in the Immediate Postoperative Period of Cardiac Surgery: A Systematic Review and Meta-Analysis

INTRODUCTION

This study aimed to evaluate the efficacy of respiratory muscle training during the immediate postoperative period of cardiac surgery on respiratory muscle strength, pulmonary function, functional capacity, and length of hospital stay.

METHODS

This is a systematic review and meta-analysis. A comprehensive search on PubMed®, Excerpta Medica Database (or Embase), Cumulative Index of Nursing and Allied Health Literature (or CINAHL), Latin American and Caribbean Health Sciences Literature (or LILACS), Scientific Electronic Library Online (or SciELO), Physiotherapy Evidence Database (or PEDro), and Cochrane Central Register of Controlled Trials databases was performed. A combination of free-text words and indexed terms referring to cardiac surgery, coronary artery bypass grafting, respiratory muscle training, and clinical trials was used. A total of 792 studies were identified; after careful selection, six studies were evaluated.

RESULTS

The studies found significant improvement after inspiratory muscle training (IMT) (n = 165, 95% confidence interval [CI] 9.68, 21.99) and expiratory muscle training (EMT) (n = 135, 95% CI 8.59, 27.07) of maximal inspiratory pressure and maximal expiratory pressure, respectively. Also, IMT increased significantly (95% CI 19.59, 349.82, n = 85) the tidal volume. However, no differences were found in the peak expiratory flow, functional capacity, and length of hospital stay after EMT and IMT.

CONCLUSION

IMT and EMT demonstrated efficacy in improving respiratory muscle strength during the immediate postoperative period of cardiac surgery. There was no evidence indicating the efficacy of IMT for pulmonary function and length of hospital stay and the efficacy of EMT for functional capacity.

The effect of Preoperative threshold inspiratory muscle training in adults undergoing cardiac surgery on postoperative hospital stay: a systematic review

BACKGROUND

Systematic reviews have reported benefits of preoperative inspiratory muscle training in adults undergoing cardiac surgery, however there have been inconsistencies with the devices used. Threshold devices generate a constant inspiratory load independent of respiratory rate.

OBJECTIVE

To assess the effect of preoperative inspiratory muscle training using threshold devices in adults undergoing cardiac surgery.

METHODS

A literature search was conducted across five electronic databases. Seven randomized controlled trials met the inclusion criteria and were critically appraised. The primary outcome was length of hospital stay. Secondary outcomes included postoperative pulmonary complications, quality of life and mortality.

RESULTS

Seven eligible randomized controlled trials were identified with a total of 642 participants. One study was a post hoc analysis of one of the included studies. Three out of five studies reported a decrease in length of postoperative hospital stay (p < 0.05). A significant reduction in postoperative pulmonary complications was reported by three studies (p < 0.05). There were concerns with bias across all papers.

CONCLUSIONS

Preoperative threshold inspiratory muscle training has potential to reduce postoperative length of hospital stay and pulmonary complications after cardiac surgery. The evidence on quality of life and mortality is inconclusive. The overall evidence for these conclusions may be influenced by bias.

Pilates method on pulmonary function and range of motion after coronary artery bypass grafting: A clinical trial

INTRODUCTION

Coronary artery bypass grafting (CABG) can compromise pulmonary function and range of motion (ROM) of the shoulder and knee joints due to median sternotomy and saphenectomy, the Pilates method being a strategy for reducing loss.

OBJECTIVE

To evaluate the effect of applying the Pilates method on pulmonary function and ROM in patients undergoing CABG.

METHOD

ology: This is a clinical trial. Patients were evaluated preoperatively at discharge from the hospital for shoulder flexion and abduction and knee flexion-extension. In addition, vital capacity(VC), maximum inspiratory pressure(MIP), expiratory pressure(MEP) and peak expiratory flow(PEF) were evaluated. Upon discharge from the Intensive Care Unit (ICU), they were divided into a control group(CG) that received conventional assistance and Pilates(PG) was increased with Pilates method techniques.

RESULTS

40 patients were analyzed, 25 were men(61%), with a mean age of 66 ± 7 years. At the end, the left shoulder abduction in the CG was 105±9vs115 ± 8 in the PG(p = 0.03), the right shoulder abduction in the CG 104 ± 11vs116 ± 10 in the PG(p < 0.001) and right knee flexion in the CG 78 ± 13vs92 ± 9 in the PG(0.002). In relation to MIP, the CG had a loss of 32 ± 8 while the PG 18 ± 10cmH2O(p < 0.001), the worsening MEP was 31 ± 9(CG)vs29 ± 11cmH2O(PG)(p = 0.53), the VC in the CG reduced 8±9vs6±8 in the PG(p = 0.23) and the PEF reduced 107 ± 5 in the GCvs83 ± 88 in the PG(p = 0.09).

CONCLUSION

It is concluded that the Pilates method decreased the loss of ROM and maximum inspiratory pressure in patients undergoing coronary artery bypass grafting.

Changes and prognostic value of cardiopulmonary exercise testing parameters in elderly patients undergoing cardiac rehabilitation: The EU-CaRE observational study

Objective

We aimed 1) to test the applicability of the previously suggested prognostic value of CPET to elderly cardiac rehabilitation patients and 2) to explore the underlying mechanism of the greater improvement in exercise capacity (peak oxygen consumption, VO₂) after CR in surgical compared to non-surgical cardiac patients.

Methods

Elderly patients (≥65 years) commencing CR after coronary artery bypass grafting, surgical valve replacement (surgery-group), percutaneous coronary intervention, percutaneous valve replacement or without revascularisation (non-surgery group) were included in the prospective multi-center EU-CaRE study. CPETs were performed at start of CR, end of CR and 1-year-follow-up. Logistic models and receiver operating characteristics were used to determine prognostic values of CPET parameters for major adverse cardiac events (MACE). Linear models were performed for change in peak VO₂ (start to follow-up) and parameters accounting for the difference between surgery and non-surgery patients were sought.

Results

1421 out of 1633 EU-CaRE patients performed a valid CPET at start of CR (age 73±5.4, 81% male). No CPET parameter further improved the receiver operation characteristics significantly beyond the model with only clinical parameters. The higher improvement in peak VO₂ (25% vs. 7%) in the surgical group disappeared when adjusted for changes in peak tidal volume and haemoglobin.

Conclusion

CPET did not improve the prediction of MACE in elderly CR patients. The higher improvement of exercise capacity in surgery patients was mainly driven by restoration of haemoglobin levels and improvement in respiratory function after sternotomy.

Trial registration

Netherlands Trial Register, Trial NL5166.

Assessment of factors affecting short-term pulmonary functions following cardiac surgery: A prospective observational study

BACKGROUND

Pulmonary complications after cardiac surgery are very common and lead to an increased incidence of post-operative morbidity and mortality. Several factors, either modifiable or non-modifiable, may contribute to the associated unfavorable consequences related to pulmonary function. This study was aimed to investigate the degree of alteration and factors influencing pulmonary function (forced expiratory volume in one second (FEV₁) and forced vital capacity), on third, fifth, and seventh post-operative days following cardiac surgery.

METHODS

This study was executed in 71 patients who underwent on-pump cardiac surgery. Pulmonary function was assessed before surgery and on the third, fifth, and seventh post-operative days. Data including surgical details, information about risk factors, and assessment of pulmonary function were obtained.

RESULTS

The FEV₁ and forced vital capacity were significantly impaired on post-operative days 3, 5, and 7 compared to pre-operative values. The reduction in FEV₁ was 41%, 29%, and 16% and in forced vital capacity was 42%, 29%, and 19% consecutively on post-operative days 3, 5, and 7. Multivariate analysis was done to detect the factors influencing post-operative FEV₁ and forced vital capacity.

DISCUSSION

This study observed a significant impairment in FEV₁ and forced vital capacity, which did not completely recover by the seventh post-operative day. Different factors affecting post-operative FEV₁ and forced vital capacity were pre-operative FEV₁, age ≥60, less body surface area, lower pre-operative chest expansion at the axillary level, and having more duration of cardiopulmonary bypass during surgery. Presence of these factors enhances the chance of developing post-operative pulmonary complications.

Influence of inspiratory muscle strength on exercise capacity before and after cardiac rehabilitation

Background/Aims

Coronary artery bypass grafting is a complex procedure that triggers a series of clinical and functional complications. The reduction of inspiratory muscle strength that persists during the late postoperative period has been suggested as an important determinant of functional capacity after coronary artery bypass grafting. The aim of this study was to investigate whether inspiratory muscle strength, functional capacity and quality of life are determinants of exercise capacity before and after a short-term phase II cardiac rehabilitation programme in patients who have had coronary artery bypass graft surgery.

Methods

A prospective quasi-experimental study was undertaken with 20 patients who had recevied coronary artery bypass surgery. All patients completed a short-term, moderate-to-high intensity inspiratory muscle training programme, followed by aerobic and resistance exercise, two times a week for 12 weeks, totalling 24 sessions, under the direct supervision of a physical therapist.

Results

Pre-intervention, peak oxygen consumption (peak VO2) was associated with maximum inspiratory pressure (β=0.037; 95% confidence interval 0.01–0.06; P=0.002). Post-intervention, peak VO2 was associated with maximum inspiratory pressure (β=0.03; 95% confidence interval 0.007–0.053; P=0.014) and the 6-Minute Walk Test (β=0.007; 95% confidence interval, 0.001–0.013; P=0.024).

Conclusions

Inspiratory muscle strength influences exercise capacity before and after a short-term cardiac rehabilitation programme in patients who have had coronary artery bypass graft surgery.

Positive expiratory pressure in postoperative cardiac patients in intensive care: A randomized controlled trial

OBJECTIVE

To evaluate effectiveness of positive expiratory pressure blow-bottle device compared to expiratory positive airway pressure and conventional physiotherapy on pulmonary function in postoperative cardiac surgery patients in intensive care unit.

DESIGN

A randomized controlled trial.

SETTINGS

Tertiary care.

SUBJECTS

48 patients (16 in each group; aged 64.5 ± 9.1 years, 38 male) submitted to cardiac surgery.

INTERVENTIONS

Patients were randomized into conventional physiotherapy (G1), positive expiratory pressure blow-bottle device (G2) or expiratory positive airway pressure, both associated with conventional physiotherapy (G3). G2 and G3 performed three sets of 10 repetitions in each session for each technique.

MAIN MEASURES

Pulmonary function (primary); respiratory muscle strength, radiological changes, pulmonary complications, length of intensive care unit and hospital stay (secondary) assessed preoperatively and on the 3rd postoperative day.

RESULTS

Pulmonary function (except for forced expiratory volume in one second/ forced vital capacity % predicted) and respiratory muscle strength showed significant reduction from the preoperative to the 3rd postoperative in all groups (P < 0.001), with no difference between groups (P > 0.05). Regarding radiological changes, length of intensive care unit stay and length of hospital stay, there was no significant difference between groups (P > 0.05).

CONCLUSION

Both positive expiratory pressure techniques associated with conventional physiotherapy were similar, but there was no difference regarding the use of positive expiratory pressure compared to conventional physiotherapy.

CLINICAL TRIAL REGISTRATION NUMBER

NCT03639974.https://clinicaltrials.gov/ct2/show/NCT03639974.

Effect of cardiac surgery on respiratory muscle strength

Objectives

Pulmonary complications, such as atelectasis, pulmonary oedema, pleural effusion, bronchospasm, and pneumonia, have been reported following cardiac surgery. Shallow breathing leading to impaired lung function is the major cause of respiratory complications. Decreases in respiratory muscle strength can be measured using the maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) produced in the oral cavity. This study aimed to determine the decrease in respiratory muscle strength 8 weeks following cardiac surgery. Moreover, the relationship between lung function and respiratory muscle strength was studied.

Methods

In this observational study, 42 adult cardiac surgery patients (10 women, 32 men; mean age 65 ± 7 years) were investigated. Lung function and respiratory muscle strength were measured preoperatively and at 2 months postoperatively.

Results

The pre- and postoperative respiratory muscle strengths were in accordance with the predicted values. The MIP was 81.75 ± 22.04 cmH₂O preoperatively and 74.56 ± 18.86 cmH₂O at the 2-month follow-up (p = 0.146). The MEP was 98.55 ± 22.24 cmH₂O preoperatively and 88.86 ± 18.14 cmH₂O at the 2-month follow-up (p = 0.19). The preoperative lung function was in accordance with the predicted values; however, lung function significantly decreased postoperatively. At the 2-month follow-up, there was a moderate correlation between the MIP and forced expiratory volume (r = 0.59, p = 0 .0078).

Conclusions

The respiratory muscle strength was not impeded either before or 2 months after cardiac surgery. However, the exact mechanism for the alteration in lung function remains unclear. Measures to re-establish the ideal postoperative lung capacity should concentrate on different perioperative pulmonary exercises.

Comparisons and correlations of pain intensity and respiratory and peripheral muscle strength in the pre- and postoperative periods of cardiac surgery

OBJECTIVE

To evaluate respiratory and peripheral muscle strength after cardiac surgery. Additionally, we compared the changes in these variables on the third and sixth postoperative days.

METHODS

Forty-six patients were recruited, including 17 women and 29 men, with a mean age of 60.50 years (SD = 9.20). Myocardial revascularization surgery was performed in 36 patients, replacement of the aortic valve in 5 patients, and replacement of the mitral valve in 5 patients.

RESULTS

A significant reduction in respiratory and peripheral muscle strength and a significant increase in pain intensity were observed on the third and sixth postoperative days (p < 0.05), except for the variable maximal inspiratory pressure; on the sixth postoperative day, maximal inspiratory pressure values were already similar to the preoperative and predicted values (p > 0.05). There was an association between peripheral muscle strength, specifically between maximal expiratory pressure preoperatively (rs = 0.383; p = 0.009), on the third postoperative day (rs = 0.468; p = 0.001) and on the sixth postoperative day (rs = 0.311; p = 0.037). The effect sizes were consistently moderate-to-large for respiratory muscle strength, the Medical Research Council scale and the visual analog scale, in particular between preoperative assessment and the sixth postoperative day.

CONCLUSION

There is a decrease in respiratory and peripheral muscle strength after cardiac surgery. In addition, maximal expiratory pressure is the variable that is most associated with peripheral muscle strength. These variables, especially respiratory and peripheral muscle strength, should be considered by professionals working in the intensive care setting.