Effectiveness of Incentive Spirometry on Inspiratory Muscle Strength After Coronary Artery Bypass Graft Surgery.

BACKGROUND: Although the use of incentive spirometry with a deep breathing exercise (DBE) is widely used in clinical practice in patients who have undergone coronary artery bypass graft (CABG) surgery, the effect of this combination therapy has not been conclusively elucidated. The aim of this study was to investigate the effect of postoperative combined incentive spirometry and DBE versus DBE alone on inspiratory muscle strength following CABG. METHOD: This randomised clinical trial was conducted in patients scheduled to undergo CABG surgery at Siriraj Hospital, Bangkok Thailand. The study group received incentive spirometry and DBE, and the control group received DBE only. Maximal inspiratory pressure (MIP) before surgery and at day 4 after surgery was assessed by a respiratory pressure meter. Secondary outcomes, including postoperative pulmonary complication and duration of postoperative hospitalisation, were obtained from the medical records. RESULTS: Ninety (90) patients were included, with 47 and 43 patients assigned to the study and control groups, respectively. In both groups, there was a significant reduction in MIP from preoperative baseline to postoperative day 4; however, the MIP in the incentive spirometry group had a significantly smaller reduction in MIP compared with the control group (33.0±23.2% vs 47.2±20.1%, respectively; p=0.006, 95% confidence interval, 3.9-23.3). There was no difference between groups regarding secondary outcomes. CONCLUSIONS: Patients in the study group had significantly better recovery of inspiratory muscle strength on day 4 post-CABG than patients in the control group. There was no significant difference between groups for either postoperative pulmonary complications or length of hospital stay.

Impact of pulmonary hypertension on exercise performance in patients with interstitial lung disease undergoing evaluation for lung transplantation.

BACKGROUND AND OBJECTIVE: Pulmonary hypertension (PH) is a known complication in patients with interstitial lung disease (ILD). Cardiopulmonary exercise testing (CPET) is an essential tool for the assessment of patients with cardiac and pulmonary diseases due to its prognostic and therapeutic implications. Few studies have evaluated the relationship between CPET response and mean pulmonary artery pressures (mPAP) in ILD. The purpose of the present study was to determine and compare the potential correlations between CPET, 6-min walk test (6MWT), pulmonary function testing (PFT) and PH in patients with ILD being evaluated for lung transplantation. METHODS: The present study reviewed patients with ILD who received lung transplantations and had CPETs within 2 years before transplantation, right heart catheterizations, PFTs and 6MWTs within 4 months of CPET. RESULTS: A total of 72 patients with ILD were analysed; 36% had PH. There were significant correlations between mPAP and CPET parameters in patients with PH; but mPAP had no impact on percent of predicted diffusion capacity of the lung for carbon monoxide or 6-min walk distance (6MWD). CPET parameters were able to detect differences between levels of severity of PH through the use of the ratio of minute ventilation to rate of carbon dioxide production (VE/VCO2) and the partial pressure of end-tidal carbon dioxide. CONCLUSIONS: This is the first study that analyses 6MWD, PFT and CPET in patients with ILD awaiting lung transplantation with and without PH. The present study demonstrates the significant impact of PH on exercise capacity and performance in patients with ILD awaiting lung transplantation.

Comparing cardiopulmonary exercise testing in severe COPD patients with and without pulmonary hypertension.

PURPOSE: To determine; (i) the effect of PH on exercise capacity, gas exchange and oxygen pulse; (ii) the variables that correlate with mean pulmonary artery pressure (mPAP) in severe COPD patients. METHODS: We reviewed 98 severe COPD patients who had pulmonary function, right heart catheterisation, and cardiopulmonary exercise testing (CPET) performed within six months of each other. PH was defined by a resting mPAP > 25 mmHg. COPD patients with and without PH were compared using the independent samples t-test and Mann-Whitney U test. Pearson correlation coefficients were used to assess the relationship between continuous variables. RESULTS: PH was present in 32% of patients and the majority of PH was mild (mPAP, 25-35 mmHg). Peak workload, oxygen uptake and oxygen pulse on CPET were significantly lower in the PH group. Mean PAP was found to inversely correlate with peak oxygen uptake, with a tendency towards lower six-minute walk distance. No difference between two groups was seen in any of the gas exchange variables. CONCLUSION: In severe COPD, there is a relatively high percentage of PH which causes a decrease in exercise capacity and oxygen pulse without significantly altered ventilation as measured by CPET. Lower than expected exercise performance without a change in pulmonary function may indicate a need for evaluation for possible PH.

Distinguishing pulmonary hypertension in interstitial lung disease by ventilation and perfusion defects measured by cardiopulmonary exercise testing.

BACKGROUND: Pulmonary hypertension (PH) is common in interstitial lung disease (ILD). Since cardiopulmonary exercise testing (CPET) is useful in understanding the pathophysiology of respiratory disorders and can distinguish between ventilation and perfusion (V/Q) defects, it may have a role in the detection of PH in ILD. We evaluated whether CPET can detect PH through analysis of V/Q defects in ILD. OBJECTIVES: We aimed to use CPET to determine if there are changes in the ventilation and the activity pattern of mixed-expired carbon dioxide pressure (PECO2) and end-tidal carbon dioxide pressure (PetCO2) in ILD patients with and without PH. METHODS: A retrospective chart review was done of all patients who received lung transplants at the Columbia University Medical Center between 2000 and 2011 with the diagnosis of ILD. CPETs were performed during the 2 years prior to transplantation; right heart catheterizations and pulmonary function tests were performed within 4 months of CPET. RESULTS: The ILD patients with PH demonstrated significantly lower PetCO2 and PECO2 during certain levels of exercise with a distinctive activity pattern for PECO2/PetCO2. CONCLUSIONS: Evaluation of V/Q defects through the PECO2 and PetCO2 patterns on CPET in ILD patients can distinguish between patients with and without PH.

Exercise capacity and ventilatory response during exercise in COPD patients with and without ß blockade.

BACKGROUND: Although ß blockade (BB) in patients with chronic obstructive pulmonary disease (COPD) does not show signs of worsening pulmonary function or respiratory symptoms, the effects on cardiopulmonary exercise testing (CPET) remain unclear. The aim of this study was to determine whether BB affects exercise capacity, gas exchange, and hemodynamic responses in patients with COPD. METHODS: Twenty-four COPD subjects on BB were matched to 24 COPD subjects without BB according to age, gender, body mass index, and severity of COPD. All subjects underwent resting pulmonary function and symptom-limited CPET. RESULTS: Comparing COPD patients with and without BB revealed that percent peak oxygen consumption and VE/VCO2 nadir were not significantly different (45 ± 16 vs. 51 ± 23 %, p = 0.30, and 35.1 ± 8.5 vs. 36.2 ± 11.6 %, p = 0.69). Systolic blood pressure and heart rate at peak exercise were significantly decreased in COPD patients with BB (168 ± 16 vs. 185 ± 20 mmHg, and 109 ± 16 vs. 122 ± 14 bpm, respectively, p < 0.05). CONCLUSION: Exercise capacity and gas exchange remain unaffected in patients with COPD in the presence of BB, although heart rate and blood pressure are lower. These findings imply that BB does not adversely affect functional capacity in patients with COPD.

Independent predictors and equation of six-minute walk test in post-cardiac surgery.

BACKGROUND: The six-minute walk test (6MWT) has been used to evaluate postsurgical recovery in cardiac patients. No previous study has compared the 6MWT at follow-up with a baseline, or evaluated the long-term effects of cardiac surgery on post-discharge 6MWT OBJECTIVES: To identify the factors independently associated with 6MWD, and to develop an equation to predict 6MWT at the 4-6-week follow-up after post-cardiac surgery hospital discharge. METHODS: Patient data of elective coronary artery bypass graft (CABG) or non-CABG surgery patients were retrospectively collected. The 6MWT was performed at hospital discharge and at the 4-6-week follow-up. Available demographic and clinical data of patients were analyzed to determine the independent factors of 6MWT. An equation to predict 6MWT were generated by forward stepwise multiple linear regression analysis. RESULTS: The data of 275 patients (mean age: 62.20±14.57 years, 64.7% male) were analyzed. The mean 6MWT was 179.14±92.18 m at discharge, and increased to 335.20±115.51 m at the 4-6-week follow-up. The 6MWT at the 4-6-week follow-up was independently correlated with 6MWT at discharge, regular exercise, age, gender, and preoperative New York Heart Association (NYHA) classification. CONCLUSION: The independent predictors: 6MWT at discharge, regular exercise, age, gender, and NYHA classification were used to generate an equation to predict 6MWT at 4-6 weeks after hospital discharge.

Effects of Buddhist walking meditation on exercise capacity and quality of life of patients with chronic heart failure: A randomized controlled trial.

BACKGROUND: Buddhist walking meditation (BWM) is widely practiced in many countries. However, there is a lack of evidence relating to its effectiveness for patients with heart failure (HF). PURPOSE: To determine the effects of a six-week BWM program on exercise capacity, quality of life, and hemodynamic response in patients with chronic HF. METHODS: Patients with HF were randomly assigned to a BWM program or an aerobic exercise program. Each group trained at least three times a week during the six-week study period. The outcome measures included exercise capacity (six-minute walk test), disease-specific quality of life (Minnesota Living with Heart Failure Questionnaire), and hemodynamic response (blood pressure and heart rate) immediately after the six weeks of training. RESULTS: The study enrolled 48 patients with a mean age of 65 years and a New York Heart Association functional class of II and III. At baseline, there were no significant differences in their clinical and demographic characteristics or the outcome measures. Although six patients withdrew, all participants were included in the intention-to-treat analysis. There was no statistically significant increase in the functional capacity of the BWM group; however, there was a significant improvement for the aerobic group. With both groups, there was no significant improvement in quality of life or most hemodynamic responses. CONCLUSIONS: The six-week BWM program did not improve the functional capacity, quality of life, or hemodynamic characteristics of the HF patients, compared with the values of the patients in the aerobic exercise program.

Effect of lung transplantation on heart rate response to exercise.

OBJECTIVES: To evaluate if patients have a change in percent of predicted heart rate reserve used at peak exercise (%HRR) after lung transplantation, even at matching workloads. BACKGROUND: Lung disease of obstructive, restrictive, and mixed types may be associated with an autonomic imbalance. Lung transplantation may improve the effects of pulmonary disease on cardiac function. However, the effect of lung transplantation on heart rate responses during exercise has not been investigated in detail. METHODS: Retrospective review of patients who underwent lung transplantation. Pre and post transplant cardiopulmonary exercise tests were reviewed. RESULTS: The %HRR significantly improved by a median of 37% (p < 0.001) following lung transplantation. When matching workloads were analyzed, the %HRR also decreased from a median of 36% to 24% (p < 0.001). CONCLUSIONS: Corresponding to an increase in peak exercise capacity, percentage of heart rate reserve used improves significantly after lung transplantation, even at matching workloads, indicating a likely improvement in autonomic modulation.

Ventilatory efficiency before and after lung volume reduction surgery.

BACKGROUND: Lung volume reduction surgery (LVRS) has been shown to improve the clearance of carbon dioxide and minute ventilation (V̇E) in select patients with COPD. One variable often assessed in COPD is ventilatory efficiency (V̇E/V̇CO2 ). METHODS: We compared 55 LVRS subjects with 25 controls from the National Emphysema Treatment Trial. V̇E/V̇CO2 was calculated from cardiopulmonary exercise testing at baseline and 6-months. We sought to assess V̇E/V̇CO2 changes with LVRS compared with controls who only received standard medical care. RESULTS: At 6 months, the LVRS group significantly increased peak V̇O2 , work load, V̇E, V̇CO2 , and tidal volume while lowering peak and lowest V̇E/V̇CO2 (improved ventilatory efficiency) and end-tidal carbon dioxide pressure. The control group did not display these changes. The changes were greatest in the LVRS subjects who improved their exercise capacity after surgery (> 10 W). CONCLUSIONS: The changes were greatest in the LVRS subjects who showed the most functional improvement, indicating an association of improved ventilation with improved functional outcome.

Comparison of cardiopulmonary exercise testing variables in COPD patients with and without coronary artery disease.

BACKGROUND: Coronary artery disease (CAD) is a common concomitant condition and an important cause of morbidity and mortality in patients with chronic obstructive pulmonary disease (COPD). Since COPD and CAD can both independently cause reduced exercise capacity, it is reasonable to hypothesize that the combination of these diseases may compound the abnormalities observed during cardiopulmonary exercise testing (CPET). However, little is known about the impact of CAD on the CPET response in COPD patients. The aim of this study is to compare exercise capacity and gas exchange variables in COPD patients with and without CAD. METHODS: Fifty-four COPD subjects without CAD (COPDnoCAD) were matched to 54 COPD subjects diagnosed with CAD (COPD/CAD) according to age, gender, body mass index and severity of COPD. All subjects underwent resting pulmonary function and symptom-limited CPET. RESULTS: Comparing COPDnoCAD patients with COPD/CAD patients revealed that exercise capacity, as measured by % peak oxygen consumption (42 ± 16% vs 53 ± 19%, p = 0.002) and % peak wattage (23 ± 13% vs 32 ± 16%, p = 0.001), was significantly lower in COPD/CAD. Ventilatory response, as measured by VE/VCO2 nadir (36 ± 9 vs 32 ± 5, p = 0.001), was significantly higher in COPD/CAD, with % peak VO2 and VE/VCO2 nadir correlating to % FEV1 and inversely correlating with %DLCO. CONCLUSION: COPD patients with CAD have significantly impaired CPET responses with lower exercise capacity and impaired gas exchange compared to COPD patients without CAD. These findings may affect the clinical interpretation of CPET data in COPD patients who have concomitant CAD.

Commercial insurance coverage for outpatient cardiac rehabilitation in patients with heart failure in the United States.

BACKGROUND: Although cardiac rehabilitation (CR) improves outcomes in patients with heart failure (HF), studies suggest variable uptake by patients with HF, as well as variable coverage by insurance carriers. The purpose of this study was to determine the percentage of large commercial health insurance companies that provide coverage for outpatient (CR) for patients with HF. METHODS: We identified a sample of the largest US commercial health care providers and analyzed their CR coverage policies for patients with HF. We surveyed 44 large private health care insurance companies, reviewed company Web sites, and, when unclear, contacted companies by e-mail or telephone. We excluded insurance clearinghouses because they did not directly provide health care insurance. RESULTS: Of 44 eligible insurance companies, 29 (66%) reported that they provide coverage for outpatient CR in patients with HF. The majority of companies (83%) covered CR for patients with any type of HF. A minority (10%) did not cover CR for patients with HF if it was considered a preexisting condition. CONCLUSIONS: A significant percentage of commercial health care insurance companies in the United States report that they currently cover outpatient CR for patients with HF. Because health insurance coverage is associated with patient participation in CR, it is anticipated that patients with HF will increasingly participate in CR in coming years.

Differences in gas exchange between severities of chronic obstructive pulmonary disease.

Impaired ventilation on cardiopulmonary exercise test (CPET) is seen in patients with chronic obstructive pulmonary disease (COPD). However, evaluation of the differences of abnormal gas exchange in COPD according to GOLD severity criteria is limited. A retrospective review was performed on all COPD patients referred for CPET at our center between 1998 and 2010. There were 548 patients compared according to GOLD severity. GOLD groups were significantly different from each other in regards to pressure of end-tidal carbon dioxide ( [Formula: see text] ) with progressively higher [Formula: see text] with increasing GOLD severity. Ratio of minute ventilation to carbon dioxide production ( [Formula: see text] ) and exercise capacity as measured by and [Formula: see text] % and work rate in watts% was inversely proportional to GOLD severity. Breathing reserve, minute ventilation, and tidal volume at peak exercise were significantly decreased with increasing disease severity between GOLD groups. We concluded that gas exchange is distinctive among different GOLD severity groups; specifically, GOLD 3 and 4 have a significantly higher [Formula: see text] and a significantly lower [Formula: see text] than GOLD 2.

Right ventricular stroke work index as a negative predictor of mortality and initial hospital stay after lung transplantation.

BACKGROUND: Studies have shown that patients with poor pre-lung transplant (LTx) right ventricular (RV) function have prolonged post-operative ventilation time and intensive care stay as well as a higher risk of in-hospital death. RV stroke work index (RVSWI) calculates RV workload and contractility. We hypothesized that patients with higher RV workload capacity, indicated by higher RVSWI, would have better outcomes after LTx. METHODS: A retrospective record review was performed on all LTx patients between 2005 and 2011 who had right heart catheterizations (RHC) 1-year before LTx. In addition, results for echocardiograms and cardiopulmonary exercise testing within 1-year of RHCs were gathered. RESULTS: Mean RVSWI was 9.36 ± 3.59 for 115 patients. There was a significant relation between mean pulmonary artery pressure (mPAP), RVSWI, RV end-diastolic diameter (RVEDd), left atrial dimension (LAD), peak and resting pressure of end-tidal carbon dioxide, minute ventilation /volume of carbon dioxide production, and 1-year mortality after LTx. Contrary to our hypothesis, those who survived had lower RVSWI than those who died within 1 year (8.99 ± 3.38 vs 11.6 ± 4.1, p = 0.026). Hospital length of stay significantly correlated with mPAP, RVSWI, left ventricular ejection fraction, percentage of fractional shortening, RVEDd, RV fractional area change, LAD, and RV wall thickness in diastole. Intensive care length of stay also significantly correlated with these variables and with body mass index. RVSWI was significantly different between groups of different RV function, indicating that increased RVSWI is associated with impairment of RV structure and function in patients undergoing LTx evaluation. CONCLUSIONS: This study demonstrates an association between 1-year mortality, initial hospital and intensive care length of stay, and pre-LTx RVSWI. Increased mPAP is a known risk for outcomes in LTx patients. Our findings support this fact and also show increased mortality with elevation of RVSWI, demonstrating the value of RV function in the assessment of risk for pre-LTx patients.