Gait speed as an incremental predictor of mortality and major morbidity in elderly patients undergoing cardiac surgery. Does removal of deep breathing exercises from a physiotherapy program including pre-operative education and early mobilisation after cardiac surgery alter patient outcomes? Does the mode of exercise influence recovery of functional capacity in the early postoperative period after coronary artery bypass graft surgery? A randomized controlled trial. Addition of Frailty and Disability to Cardiac Surgery Risk Scores Identifies Elderly Patients at High Risk of Mortality or Major Morbidity Effects of physical training on the recovery of the autonomic nervous activity during exercise after coronary artery bypass grafting: effects of physical training after CABG. Early 4‐Week Cardiac Rehabilitation Exercise Training in Elderly Patients After Heart Surgery Supervised moderate intensity exercise improves distance walked at hospital discharge following coronary artery bypass graft surgery--a randomised controlled trial. Short-term supervised inpatient physiotherapy exercise protocol improves cardiac autonomic function after coronary artery bypass graft surgery – a randomised controlled trial Exercise therapy after coronary artery bypass graft surgery: a randomized comparison of a high and low frequency exercise therapy program. Early and Late Rehabilitation and Physical Training in Elderly Patients After Cardiac Surgery Home-Based Versus In-Hospital Cardiac Rehabilitation After Cardiac Surgery: A Nonrandomized Controlled Study Effects of Aerobic Exercise Applied Early After Coronary Artery Bypass Grafting on Pulmonary Function, Respiratory Muscle Strength, and Functional Capacity: A Randomized Controlled Trial. Telephonically-monitored home exercise early after coronary artery bypass surgery. Inspiratory muscle strength as a determinant of functional capacity early after coronary artery bypass graft surgery. Preoperative 6-minute walk test adds prognostic information to Euroscore in patients undergoing aortic valve replacement
OBJECTIVES The purpose of this study was to test the value of gait speed , a clinical marker for frailty , to improve the prediction of mortality and major morbidity in elderly patients undergoing cardiac surgery . BACKGROUND It is increasingly difficult to predict the elderly patient 's risk posed by cardiac surgery because existing risk assessment tools are incomplete . METHODS A multicenter prospect i ve cohort of elderly patients undergoing cardiac surgery was assembled at 4 tertiary care hospitals between 2008 and 2009 . Patients were eligible if they were 70 years of age or older and were scheduled for coronary artery bypass and /or valve replacement or repair . The primary predictor was slow gait speed , defined as a time taken to walk 5 m of ≥ 6 s. The primary end point was a composite of in-hospital post-operative mortality or major morbidity . RESULTS The cohort consisted of 131 patients with a mean age of 75.8 ± 4.4 years ; 34 % were female patients . Sixty patients ( 46 % ) were classified as slow walkers before cardiac surgery . Slow walkers were more likely to be female ( 43 % vs. 25 % , p = 0.03 ) and diabetic ( 50 % vs. 28 % , p = 0.01 ) . Thirty patients ( 23 % ) experienced the primary composite end point of mortality or major morbidity after cardiac surgery . Slow gait speed was an independent predictor of the composite end point after adjusting for the Society of Thoracic Surgeons risk score ( odds ratio : 3.05 ; 95 % confidence interval : 1.23 to 7.54 ) . CONCLUSIONS Gait speed is a simple and effective test that may identify a subset of vulnerable elderly patients at incrementally higher risk of mortality and major morbidity after cardiac surgery The aim of this study was to establish whether removal of breathing exercises from a regimen including early mobilisation changes the incidence of post-operative pulmonary complications for patients after cardiac surgery . Two hundred and thirty patients undergoing open heart surgery at Monash Medical Centre , Melbourne , were enrolled in this r and omised controlled trial . All patients received physiotherapy treatment pre-operatively and post-operatively for three days . Patients were mobilised as soon as possible after surgery . Breathing group ( control ) patients performed a set routine of deep breathing exercises at each physiotherapy visit while those in the intervention group did not perform this routine . Other than the breathing exercises , patient management was similar between groups in terms of assessment , positioning and mobility . The incidence of postoperative pulmonary complications , post-operative length of stay , oxyhaemoglobin saturation and pulmonary function were measured pre-operatively and post-operatively . Intention-to-treat analysis was performed for post-operative pulmonary complications and length of stay . Other data were analysed using t-tests , chi square and repeated measures analysis of variance . There were no significant differences between the groups in the primary dependent variables . It is concluded that removal of breathing exercises from the routine physiotherapy management of open heart surgery patients does not significantly alter patient outcome OBJECTIVES The purpose of this study was to compare the effectiveness of moderate-intensity stationary cycling and walking exercise programmes in the early postoperative period after first-time coronary artery bypass graft surgery . METHODS In this prospect i ve trial , 64 patients ( 57 men , 7 women , mean age = 66 ± 9 years ) performed twice daily , moderate-intensity exercise sessions  , of 10-min duration , from postoperative day 3 until discharge from hospital . Patients were r and omly assigned to stationary cycling or walking exercise intervention groups . Preoperative and discharge functional exercise capacity and health-related quality of life were assessed using 6-min walk and cycle assessment s and the SF-36 version 2.0 question naire . Compliance with exercise was calculated as the proportion of scheduled exercise sessions completed . RESULTS There were no significant differences between intervention groups at hospital discharge for 6-min walk distance ( cyclists : 402 ± 93 m vs walkers : 417 ± 86 m , P = 0.803 ) , 6-min cycle work ( cyclists : 15.0 ± 6.4 kJ vs walkers : 14.0 ± 6.3 kJ , P = 0.798 ) or health-related quality of life . There was no significant difference between intervention groups for postoperative length of hospital stay ( P = 0.335 ) . Compliance rates for intervention groups were cyclists : 185/246 ( 75 % ) scheduled exercise sessions completed vs walkers : 199/242 ( 82 % ) scheduled exercise sessions completed ( P = 0.162 ) . CONCLUSIONS Stationary cycling provides a well-tolerated and clinical ly effective alternative to walking in the early postoperative period after coronary artery bypass graft surgery . The optimal frequency , intensity and duration of exercise in the early postoperative period require further investigation . ( Clinical trials register : Australian New Zeal and Clinical Trials Registry ; identification number : ACTRN12608000359336 ; http://www.anzctr.org.au/trial_view.aspx?ID=82978 ) Background — Cardiac surgery risk scores perform poorly in elderly patients , in part because they do not take into account frailty and disability which are critical determinants of health status with advanced age . There is an unmet need to combine established cardiac surgery risk scores with measures of frailty and disability to provide a more complete model for risk prediction in elderly patients undergoing cardiac surgery .  Methods and Results — This was a prospect i ve , multicenter cohort study of elderly patients ( ≥70 years ) undergoing coronary artery bypass and /or valve surgery in the United States and Canada . Four different frailty scales , 3 disability scales , and 5 cardiac surgery risk scores were measured in all patients . The primary outcome was the STS composite end point of in-hospital postoperative mortality or major morbidity . A total of 152 patients were enrolled , with a mean age of 75.9±4.4 years and 34 % women . Depending on the scale used , 20–46 % of patients were found to be frail , and 5–76 % were found to have at least 1 disability . The most predictive scale in each domain was : 5-meter gait speed ≥6 seconds as a measure of frailty ( odds ratio [ OR ] , 2.63 ; 95 % confidence interval [ CI ] , 1.17–5.90 ) , ≥3 impairments in the Nagi scale as a measure of disability ( OR , 2.98 ; 95 % CI , 1.35–6.56 ) and either the Parsonnet score ( OR , 1.08 ; 95 % CI , 1.04–1.13 ) or Society of Thoracic Surgeons Predicted Risk of Mortality or Major Morbidity ( STS-PROMM ) ( OR , 1.05 ; 95 % CI , 1.01–1.09 ) as a cardiac surgery risk score . Compared with the Parsonnet score or STS-PROMM alone , ( area under the curve , 0.68–0.72 ) , addition of frailty and disability provided incremental value and improved model discrimination ( area under the curve , 0.73–0.76 ) . Conclusions — Clinicians should use an integrative approach combining frailty , disability , and risk scores to better characterize elderly patients referred for cardiac surgery and identify those that are at increased risk Analysis of heart rate variability ( HRV ) can identify patients at risk of sudden cardiac death after myocardial infa rct ion . The present study examined the effect of 2 weeks of supervised aerobic exercise training on the recovery of the autonomic nervous activity , exercise capacity , and cardiac output ( CO ) after  coronary artery bypass grafting ( CABG ) . Twenty-eight patients were r and omly divided into the training group or the control group and performed exercise tests at 1 week , 3 weeks , 3 months , 6 months and 1 year after CABG . The HRV was measured , and the high-frequency component of HRV was used as an index of parasympathetic nerve activity ( PNA ) ; the plasma norepinephrine concentration ( NE ) was used as an index of sympathetic nervous activity . Cardiac output was also measured . In the training group , peak VO2 , peak CO and PNA during exercise had improved at 3 weeks , but there was no improvement in these indices in the control group . NE decreased 1 week after CABG in both groups . These results indicate that physical training soon after CABG improves not only the exercise capacity , but also PNA PURPOSE The aim of this study was to assess the effects on exercise performance of supplementing a st and ard cardiac rehabilitation program with additional exercise programming compared to the st and ard cardiac rehabilitation program alone in elderly patients after heart surgery . METHODS In this prospect i ve , r and omized controlled trial , 60 patients ( 32 men and 28 women , mean age 73.1 ± 4.7 years ) completed cardiac rehabilitation ( initiated 12.2 ± 4.9 days postsurgery ) . Subjects were assigned to either a control group ( CG , st and ard cardiac rehabilitation program [ n = 19 ] ) , or an intervention group ( IG , additional walking [ n = 19 ] , or cycle ergometry training [ n = 22 ] ) . A symptom limited cardiopulmonary exercise test and 6-minute walk test ( 6MWT ) were performed before and after 4 weeks of cardiac rehabilitation . The MacNew question naire was used to assess quality of life ( QOL ) . RESULTS At baseline , no significant differences for peak oxygen uptake ( & OV0312;O2 ) , maximal power output , or the 6MWT were detected between IG and CG . Global QOL was significantly higher in IG . After 4 weeks of cardiac rehabilitation , patients significantly improved in absolute values of the cardiopulmonary exercise test , 6MWT , and QOL scores . Significant differences between groups were found for peak & OV0312;O2 ( IG : 18.2 ± 3.1 mL·kg−1·min−1 vs. CG : 16.5 ± 2.2 mL·kg−1·min−1 , P < .05 ) ; maximal power output ( IG : 72.2 ± 16 W vs. CG : 60.7 ± 15 W , P < .05 ) ; 6MWT ( IG : 454.8 ± 76.3 m vs. CG : 400.5 ± 75.5 m , P < .05 ) ; and QOL global ( IG : 6.5 ± 0.5 vs. CG : 6.3 ± 0.6 , P < .05 ) . CONCLUSION The supplementation of additional walking or cycle exercise training to st and ard cardiac rehabilitation programming compared to st and ard cardiac rehabilitation alone in elderly patients after heart surgery leads to significantly better exercise tolerance BACKGROUND This study aim ed to determine whether a structured , inpatient ( or Phase 1 cardiac rehabilitation ) , physiotherapy-supervised walking program , with or without musculoskeletal and respiratory exercises , might improve walking capacity and other parameters for patients undergoing coronary artery bypass graft surgery ( CABG ) . METHODS Ninety-three patients awaiting first-time CABG over a 12-month period were r and omised to one of three post-operative physiotherapy regimens : ' st and ard intervention ' , consisting of gentle mobilisation ; ' walking exercise ' , consisting of a physiotherapy-supervised , moderate intensity walking program ; and ' walking/breathing exercise ' , consisting of the same moderate intensity walking program , musculoskeletal exercises and respiratory exercises . Primary outcomes ; six-minute walking assessment ( 6MWA ) distance , vital capacity and health-related quality of life , were measured pre-operatively , at discharge from hospital and at four weeks following discharge . RESULTS Walking and walking/breathing exercise groups had significantly higher 6MWA distance ( 444+/-84 m , 431+/-98 m , respectively ) than the st and ard intervention group ( 377+/-90 m ) at discharge from hospital . There was no significant difference between intervention groups for 6MWA distance at four-week follow-up . There was no significant difference between intervention groups in terms of vital capacity and health-related quality of life . CONCLUSIONS A physiotherapy-supervised , moderate intensity walking program in the inpatient phase following CABG improves walking capacity at discharge from hospital . The performance of respiratory and musculoskeletal exercises confers no additional benefit to the measured outcomes Objective . Coronary artery bypass grafting ( CABG )  is accompanied by severe impairment of cardiac autonomous regulation ( CAR ) . This study aim ed to determine whether a short-term physiotherapy exercise protocol post-CABG , during inpatient cardiac rehabilitation ( CR ) , might improve CAR . Design . Seventy-four patients eligible for CABG were recruited and r and omised into physiotherapy exercise group ( EG ) or physiotherapy usual care group ( UCG ) . EG patients underwent a short-term supervised inpatient physiotherapy exercise protocol consisting of an early mobilisation with progressive exercises plus usual care ( respiratory exercises ) . UCG only received respiratory exercises .  Forty-seven patients ( 24 EG and 23 UGC ) completed the study . Outcome measures of CAR included linear and non-linear measures of heart rate variability ( HRV ) assessed before discharge . Results . By hospital discharge , EG presented significantly higher parasympathetic HRV values [ rMSSD , high frequency ( HF ) , SD1 ) ] , global power ( STD RR , SD2 ) , non-linear HRV indexes [ detrended fluctuation analysis (DFA)α1 , DFAα2 , approximate entropy ( ApEn ) ] and mean RR compared to UCG ( p < 0.05 ) . Conversely , higher values of mean HR , low frequency ( LF ) ( sympathetic activity ) and the LF/HF ( global sympatho-vagal balance ) were found in the UCG . Conclusions . A short-term supervised physiotherapy exercise protocol during inpatient CR improves CAR at the time of discharge . Thus , exercise-based inpatient CR might be an effective non-pharmacological tool to improve autonomic cardiac tone in patient 's post-CABG BACKGROUND Postoperative exercise therapy aims at recovering , as soon as possible , independence in the basic physical activities ; but the type , intensity , and therefore the costs of the programs , vary widely . The aim of this study was to compare the effectiveness of a low frequency ( once daily , not in the weekend ) program with a high frequency ( twice daily , including the weekend ) one and to assess whether the latter would yield sufficient benefit for the patient to justify higher costs in material and personnel ( physiotherapists ) after uncomplicated coronary artery bypass graft ( CABG ) surgery . METHODS Two-hundred and forty-six patients were r and omly allocated to either a low or high frequency exercise program . Endpoints were the functional level as measured by the achievement of five activity milestones , the patient 's independence ( functional independence measures [ FIM ] ) as assessed by a structured interview , the amount of daily physical activity ( activity monitor ) , and patient satisfaction ( question naire ) . Except for patient satisfaction , all measurements were done in the first week after surgery . RESULTS Patients with the high frequency exercise program achieved functional milestones faster than patients with the low frequency exercise program ( p = 0.007 ) . The frequency of the exercise program had no influence on functional independence as measured with the FIM or quantity of physical activity . The satisfaction degree was greater in the high frequency group ( p = 0.032 ) , although the low frequency group was not dissatisfied . CONCLUSIONS A high frequency exercise program leads to earlier performance of functional milestones and yields more satisfaction after uncomplicated CABG surgery and this should lead to an earlier discharge . On the other h and , if the shortage of physiotherapists remains unchanged or even increases , the low frequency program also yields excellent functional results , albeit at the cost of a somewhat longer hospital stay : but it would allow a sensible redistribution of the physiotherapists activity towards complicated and , therefore , more dem and ing patients Macchi C , Fattirolli F , Molino Lova R , Conti AA , Luisi MLE , Intini R , Zipoli R , Burgisser C , Guarducci L , Masotti G , Gensini GF : Early and late rehabilitation and physical training in elderly patients after cardiac surgery . Am J Phys Med Rehabil 2007;86:826–834 . Objective : Few r and omized trials have enrolled patients who have undergone cardiac surgery , and even fewer have included patients aged 75 yrs or more . Furthermore , the optimal timing of cardiac rehabilitation for postsurgical patients has not yet been codified . The aim of this study was to verify whether rehabilitation outcomes are also favorable in postsurgical patients aged 75 yrs or more and whether an early rehabilitation program is as effective and safe as a late one . Design : Three hundred patients who underwent cardiac surgery , 27.7 % of whom were at least 75 yrs old , were r and omly assigned to a rehabilitation program starting within the second week after operation or within the fourth week . All events occurring during the rehabilitation program or in the following year were recorded . Results : During the rehabilitation program , new-onset atrial fibrillation was significantly more frequent in the early rehabilitation group , independent of age class , and anemia was significantly more frequent in older patients , independent of rehabilitation timing . At the end of the rehabilitation program , more than 90 % of patients showed significant increases in walking distance , and during the follow-up , no significant difference was found with regard to mortality , nonfatal events , functional ability , or control of cardiovascular risk factors , independent of rehabilitation timing and age class . Conclusions : This study provides evidence that in selected patients who have undergone cardiac surgery , rehabilitation outcomes are also favorable in patients aged 75 yrs or more , and an early rehabilitation program is as effective and safe as a traditionally late one Background Exercise rehabilitation after cardiac surgery has beneficial effects , especially on a long-term basis . Rehabilitative programs with telemedicine plus appropriate technology might satisfy the needs of performing rehabilitation at home . Objective The purpose of this study was to compare exercise capacity after home-based cardiac rehabilitation ( HBCR ) or in-hospital rehabilitation in patients at low to medium risk for early mortality ( EuroSCORE 0–5 ) following cardiac surgery . Design A quasi-experimental study was conducted . Methods At hospital discharge , patients were given the option to decide whether to enroll in the HBCR program .  Clinical examinations ( electrocardiography , cardiac echo color Doppler , chest radiography , blood sample s ) of patients in the HBCR group were collected during 4 weeks of rehabilitation , and exercise capacity ( assessed using the Six-Minute Walk Test [ 6MWT ] ) was assessed before and after rehabilitation . A group of patients admitted to the in-hospital rehabilitation program was used as a comparison group . Patients in the HBCR group were supervised at home by a medical doctor and telemonitored daily by a nurse and physical therapist by video conference . Periodic home visits by health staff also were performed . Results One hundred patients were recruited into the HBCR group . An equal number of patients was selected for the comparison group . At the end of the 4-week study , the 2 groups showed improvement from their respective baseline values only in the 6MWT . No difference was found in time × group interaction . Limitations Because patients self-selected to enroll in the HBCR program and because they were enrolled from a single clinical center , the results of the study can not be generalized . Conclusions In patients who self-selected HBCR , the program was found to be effective and comparable to the st and ard in-hospital rehabilitative approach , indicating that rehabilitation following cardiac surgery can be implemented effectively at home when coadministered with an integrated telemedicine service BACKGROUND Physical activity is beneficial in several clinical situations and recommended for patients with ischemic heart disease , as well as for those undergoing cardiac surgery . METHODS In a r and omized controlled trial , 34 patients underwent coronary artery bypass grafting .  A r and omized control group ( n = 15 ) su bmi tted to conventional physiotherapy . The intervention group ( n = 19 ) received the same protocol plus additional aerobic exercise with cycle ergometer .  Pulmonary function by spirometry , respiratory muscle strength by manovacuometry , and functional capacity through  6-minute walking test was assessed before surgery and at hospital discharge . RESULTS There was significant reduction in pulmonary function in both groups . In both groups , inspiratory muscle strength was maintained while expiratory muscle strength significantly decreased . Functional capacity was maintained in the intervention group ( 364.5 [ 324.5 to 428 ] vs. 348 [ 300.7 to 413.7 ] meters , P = .06 ) , but it decreased significantly in control group patients ( 320 [ 288.5 to 393.0 ] vs. 292 [ 237.0 to 336.0 ] meters , P = .01 ) . A significant difference in functional capacity was also found in intergroup analyses at hospital discharge ( P = .03 ) . CONCLUSION Aerobic exercise applied early on coronary artery bypass grafting patients may promote maintenance of functional capacity , with no impact on pulmonary function and respiratory muscle strength when compared with conventional physiotherapy To evaluate the usefulness of telephonically-monitored home exercise in patients within two weeks postcoronary bypass surgery , we r and omly enrolled 46 male patients in a 12-week home program of either short walks or bicycle ergometry . Home exercise was done five times weekly and monitored both before and immediately after three times weekly . New arrhythmias or conduction disturbances were detected in 18 of 23 ( 78 percent ) of the bicycle group and in 20 of 23 ( 87 percent ) of the short walk patients . New symptoms developed in three patients , two from the short walk group and one from the bicycle group . Two bikers and one walker developed elevated blood pressure ; all were referred to physicians and were successfully managed . Electrocardiographic abnormalities led directly to diagnostic and therapeutic intervention in nine of the 46 patients -four bikers and five walkers . There were no complications such as ventricular tachycardia or ventricular fibrillation . Technically clear telephone rhythm strips were obtained from patients calling both locally and long distance UNLABELLED Stein R , Maia CP , Silveira AD , Chiappa GR , Myers J , Ribeiro JP . Inspiratory muscle strength as a determinant of functional capacity early after coronary artery bypass graft surgery . OBJECTIVE To evaluate the effects of a 6-day postoperative in-hospital cardiopulmonary rehabilitation program on inspiratory muscle strength and its potential association with improved functional capacity after coronary artery bypass graft ( CABG ) surgery . DESIGN Prospect i ve , r and omized controlled trial . SETTING Tertiary public hospital in Brazil . PARTICIPANTS Men ( N=20 ) after CABG were r and omized to cardiopulmonary rehabilitation ( n=10 ; age , 64+/-8y ) or to usual care ( n=10 ; age , 63+/-7y ) . INTERVENTIONS Ten subjects underwent a 6-day postoperative in-hospital program , which included the use of expiratory positive airway pressure mask and bronchial hygiene techniques , coupled with progressive distance walking and calisthenics as well as cardiopulmonary training .  Ten controls were followed by their own physicians and received routine nursing assistance but were not exposed to any specific respiratory or motor physical intervention . MAIN OUTCOME MEASURES Maximal inspiratory and expiratory pressure were measured by a pressure transducer , and the highest pressure obtained in 6 measurements was used for analysis ( before surgery , and 7 and 30d after surgery ) . The six-minute walk test ( 6MWT ) was performed 7 days after surgery , and maximal cardiopulmonary exercise testing was performed 30 days after CABG . RESULTS After r and omization , clinical and functional characteristics were similar in the 2 groups . Rehabilitation result ed in maintenance of maximal inspiratory pressure ( PImax ) measured at 7 and 30 days postoperatively , respectively ( from 68+/-19 % at baseline to 58+/-22 % and to 61+/-22 % predicted ) , while it was significantly reduced in the control group . 6MWT distance was longer 7 days after CABG in rehabilitation subjects ( 416+/-78 m ) than controls ( 323+/-67 m ) . Peak oxygen uptake ( Vo(2)peak ) at day 30 was also higher ( 28 % ) in the rehabilitation group and was correlated with PImax ( r=.90 ) . CONCLUSIONS A 6-day rehabilitation program attenuated the postoperative reduction in respiratory muscle strength and also improved the recovery of functional capacity after CABG . The correlation between PImax and Vo(2)peak during the late postoperative period suggests that inspiratory muscle strength is an important determinant of functional capacity after CABG Aims : The authors investigated the additive prognostic value of the 6-minute walk test ( 6MWT ) to Euroscore in patients with severe aortic stenosis undergoing aortic valve replacement ( AVR )  Methods and results : 208 patients with severe AS underwent the 6MWT before AVR , as part of a r and omised trial ( ASSERT ) comparing stented and stentless aortic valves . Clinical follow-up was available for 200 patients up to 12 months . The rate of death , myocardial infa rct ion ( MI ) or stroke ( time to first event ) was 13 % ( n = 14 ) in patients walking < 300 metres compared to 4 % ( n = 4 ) in those who walked ⩾300 metres ( p = 0.017 ) . When rate of death , MI or stroke by Euroscore risk was stratified by 6-minute walking distance , the 6MWT added prognostic information . In a Cox regression analysis 6MWT distance was the only variable retained as an independent predictor of the composite outcome of death , MI or stroke at 12 months ( HR 0.28 95 % CI 0.09 to 0.85 , p = 0.025 ) . Conclusions : The 6MWT is safe and feasible to carry out in patients with severe aortic stenosis before AVR , and provides potentially important functional and prognostic information to clinical assessment and the Euroscore risk score
Background Aerobic exercise is a critical component of cardiac rehabilitation following cardiac surgery .
Aerobic exercise is traditionally commenced 2–6 weeks following hospital discharge and most commonly includes stationary cycling or treadmill walking .
The initiation of aerobic exercise within this early postoperative period not only introduces the benefits associated with aerobic activity sooner , but also ameliorates the negative effects of immobilization associated with the early postoperative period .