title: Comparison of 19 pre-operative risk stratification models in open-heart surgery. Pre-operative short-term pulmonary rehabilitation for patients of chronic obstructive pulmonary disease undergoing coronary artery bypass graft surgery. Preoperative intensive inspiratory muscle training to prevent postoperative pulmonary complications in high-risk patients undergoing CABG surgery: a randomized clinical trial. The efficacy of the relaxation response in preparing for cardiac surgery. Postoperative pneumonia: a prospective study of risk factors and morbidity. Effect of a Preoperative Intervention on Preoperative and Postoperative Outcomes in Low-Risk Patients Awaiting Elective Coronary Artery Bypass Graft Surgery Three different mask physiotherapy regimens for prevention of post-operative pulmonary complications after heart and pulmonary surgery Short-term effects of inspiratory muscle training in coronary artery bypass graft surgery: A randomized controlled trial Determinants of hospital charges for coronary artery bypass surgery: the economic consequences of postoperative complications. Postoperative chest radiographic changes after on- and off-pump coronary surgery. A controlled trial of community based coronary rehabilitation. [Prophylactic inspiratory muscle training before coronary artery bypass graft]. Patient perception of preoperative cardiac surgical teaching done pre- and postadmission. Atelectasis and Gas Exchange after Cardiac Surgery Effects of electrostimulation of the vagus afferent endings in patients with coronary artery disease
abstract: AIMS To compare 19 risk score algorithms with regard to their validity to predict 30-day and 1-year mortality after cardiac surgery . METHODS AND RESULTS Risk factors for patients undergoing heart surgery between 1996 and 2001 at a single centre were prospect ively collected . Receiver operating characteristics ( ROC ) curves were used to describe the performance and accuracy . Survival at 1 year and cause of death were obtained in all cases . The study included 6222 cardiac surgical procedures .  Actual mortality was 2.9 % at 30 days and 6.1 % at 1 year . Discriminatory power for 30-day and 1-year mortality in cardiac surgery was highest for logistic ( 0.84 and 0.77 ) and additive ( 0.84 and 0.77 ) European System for Cardiac Operative Risk Evaluation ( EuroSCORE ) algorithms , followed by Clevel and Clinic ( 0.82 and 0.76 ) and Magovern ( 0.82 and 0.76 ) scoring systems . None of the other 15 risk algorithms had a significantly better discriminatory power than these four . In coronary artery bypass grafting (CABG)-only surgery , EuroSCORE followed by New York State ( NYS ) and Clevel and Clinic risk score showed the highest discriminatory power for 30-day and 1-year mortality . CONCLUSION EuroSCORE , Clevel and Clinic , and Magovern risk algorithms showed superior performance and accuracy in open-heart surgery , and EuroSCORE , NYS , and Clevel and Clinic in CABG-only surgery . Although the models were originally design ed to predict early mortality , the 1-year mortality prediction was also reasonably accurate The role of pre-operative short-term pulmonary rehabilitation in patients with chronic obstructive pulmonary disease who undergo coronary artery bypass graft surgery has been assessed for the first time prospect ively . Forty-five patients posted for coronary artery bypass graft surgery  were r and omised to receive either short-term pulmonary rehabilitation ( group I ) or no such programme ( group II ) . Patients of both the groups were evenly matched with respect to age , sex , body surface area , duration and severity of chronic obstructive pulmonary disease and coronary artery disease . Normal individuals who evenly matched with the study group were assessed for normal respiratory function parameters . Pre-operative and post-operative peak expiratory flow rate , inspiratory capacity , post-operative ventilation time , post-operative pulmonary complication and hospital stay were determined in both the groups . Peak expiratory flow rate ( 220.0 + /- 12.9 and 324.3 + /- 84.3 in group I , 218.0 + /- 16.4 and 260.5 + /- 35.2 in group II ) and inspiratory capacity ( 844.0 + /- 147.4 and 1100.0 + /- 158.1 in group I , 830.0 + /- 117.4 and 1090 + /- 137 in group II ) were significantly lower before and after surgery respectively in both groups compared to normal values . Even though both groups showed a significant rise in post-operative peak expiratory flow rate and inspiratory capacity after surgery , the post-operative peak expiratory flow rate and inspiratory capacity in group I was significantly higher than in group II . In group I , the post-operative ventilation time ( 24.5 + /- 6.00 hours ) , post-operative complications ( n = 4 ) and hospital stay ( 12.4 + /- 3.6 days ) were significantly lower than in group II ( 35.2 + /- 22.3 hours , n = 11 , 18.8 + /- 6.6 days respectively ) . These data suggest that short-term pulmonary rehabilitation is feasible and effective in improving pulmonary functions before and after surgery and in reducing surgical morbidity and cost of medical care significantly CONTEXT Postoperative pulmonary complications ( PPCs ) after coronary artery bypass graft ( CABG ) surgery are a major source of morbidity and mortality , and increase length of hospital stay and re source utilization . The prehospitalization period before CABG surgery may be used to improve a patient 's pulmonary condition . The efficacy of preoperative inspiratory muscle training ( IMT ) in reducing the incidence of PPCs in high-risk patients undergoing CABG surgery has not yet been determined . OBJECTIVE To evaluate the prophylactic efficacy of preoperative IMT on the incidence of PPCs in high-risk patients scheduled for elective CABG surgery . DESIGN , SETTING , AND PATIENTS A single-blind , r and omized clinical trial conducted at the University Medical Center Utrecht , Utrecht , the Netherl and s , with enrollment between July 2002 and August 2005 . Of 655 patients referred for elective CABG surgery , 299 ( 45.6 % ) met criteria for high risk of developing PPCs , of whom 279 were enrolled and followed up until discharge from hospital . INTERVENTION Patients were r and omly assigned to receive either preoperative IMT ( n = 140 ) or usual care ( n = 139 ) . Both groups received the same postoperative physical therapy . MAIN OUTCOME MEASURES Incidence of PPCs , especially pneumonia , and duration of postoperative hospitalization . RESULTS Both groups were comparable at baseline . After CABG surgery , PPCs were present in 25 ( 18.0 % ) of 139 patients in the IMT group and 48 ( 35.0 % ) of 137 patients in the usual care group ( odds ratio [ OR ] , 0.52 ; 95 % confidence interval [ CI ] , 0.30 - 0.92 ) . Pneumonia occurred in 9 ( 6.5 % ) of 139 patients in the IMT group and in 22 ( 16.1 % ) of 137 patients in the usual care group ( OR , 0.40 ; 95 % CI , 0.19 - 0.84 ) . Median duration of postoperative hospitalization was 7 days ( range , 5 - 41 days ) in the IMT group vs 8 days ( range , 6 - 70 days ) in the usual care group by Mann-Whitney U statistic ( z = -2.42 ; P = .02 ) . CONCLUSION Preoperative IMT reduced the incidence of PPCs and duration of postoperative hospitalization in patients at high risk of developing a pulmonary complication undergoing CABG surgery . TRIAL REGISTRATION is rct n.org Identifier : IS RCT N17691887 This study evaluated the efficacy of the relaxation response on the post-operative recovery of 27 cardiac surgery patients r and omly assigned to one of two groups . Thirteen experimental group patients received educational information and practice d eliciting the relaxation response before and after surgery . The 14 patients in the control group received only information . Experimental and control groups were compared before and after surgery on both physiological and psychological recovery variables . There were no initial differences between experimental and control groups on demographic , physiological , and most psychological variables . The experimental group had lower incidence of postoperative supraventricular tachycardia ( SVT ) than the control group ( p = .04 ) despite having had the same occurrence previously . Experimental and control groups did not significantly differ over the course of study on any other physiological variables . Patients practicing the relaxation response had greater decreases in psychological tension ( p = .04 ) and anger ( p = .04 ) than those who received only educational information . The decreases in psychological tension may have been a result of regression to the mean because the experimental group started with elevated tension relative to the control group ( p = .04 ) . We conclude that practicing the relaxation response before and after surgery may reduce SVT , tension , and anger BACKGROUND Postoperative pneumonia ( PP ) is a major complication that has been linked to microaspiration of pathogens originating in the gastrointestinal tract . This prospect i ve study was performed to define the role of gastric bacterial aspiration in the development of PP . METHODS Informed consent was obtained before operations from 140 veterans scheduled for major elective procedures requiring nasogastric tubes  , and cultures were obtained of the gastric contents and sputum twice daily after operation . RESULTS PP developed in 26 ( 18.6 % ) of 140 patients . The patients who had PP did not differ from those with no pneumonia after operation except for a history of chronic obstructive pulmonary disease , which was found in 38.5 % of those with PP compared with 20 % of patients with no pneumonia ( p < 0.05 ) . Morbidity was increased in association with PP , because length of stay in the surgical intensive care unit ( 6.2 vs 2.6 days ) , days intubated ( 2.7 vs 0.6 ) , total postoperative days ( 15.3 vs 8.4 ) , and mortality rates ( 19.2 % vs 1.7 % ) were greater than in patients with no pneumonia . Gastric pathogens were present on entry in 38 % of patients , and 32 % of these had PP compared with 13 % whose initial gastric cultures were sterile ( p = 0.01 ) . Colonization of sputum for greater than 24 hours with gastric pathogens occurred in 28 % of patients . These patients had a 40 % incidence of PP compared with 12 % in patients without such evidence of microaspiration ( p < 0.01 ) . CONCLUSIONS PP is a morbid postoperative complication associated with not only chronic obstructive pulmonary disease but also the presence of gastric bacteria during operation and transmission of gastric bacteria to the pulmonary tree after operation In Ontario , Canada , the discrepancy between the high dem and for  coronary artery bypass graft surgery ( CABG )  and the low immediate supply results in waiting lists . In 1990 , a consensus panel of cardiologists and surgeons developed criteria to ensure that high-risk patients were given priority for this procedure ( 1 ) . Each patient receives an acuity score that corresponds to a recommended maximum delay . Aggregated acuity scores of 4 , 5 , 6 , and 7 indicate elective status and represent a waiting time ranging from greater than 14 days to a maximum of 6 months . The mortality rate for patients awaiting CABG  has been shown to be remarkably stableapproximately 0.5 % to 0.6 % per year over the past 10 years ( 2 ) . Despite this , however , evidence shows that patients ' functional and psychological status can deteriorate during the wait for surgery ( 3 - 5 ) . Through its effects on the autonomic nervous system , emotional stress also influences catecholamines , myocardial oxygen dem and , and platelet aggregation ; this may affect morbidity during the waiting period ( 6 - 8 ) . Such factors as preoperative anxiety and little social support have adverse psychological effects during extended preoperative waiting periods and , in addition , have been found to predict poor physical recovery from heart surgery ( 9 ) . Therefore , psychological factors and physical deconditioning , both of which occur during the waiting period ( 10 - 12 ) , may negatively affect patients ' in-hospital course , including length of stay . Because waiting for health services will probably continue to be a reality in publicly funded health care systems that value universal access , careful study of simple , affordable methods to improve patient outcomes during the waiting period is warranted . We examined the effect of a minimum 8-week , multidimensional , preoperative intervention on the presurgery and postsurgery outcomes of patients awaiting elective CABG . We hypothesized that a combination of exercise training , education , and social support would affect patients ' physical and psychological readiness for surgery and thereby reduce postoperative length of hospital stay . We further hypothesized that the effectiveness of the preoperative intervention would be sustained into the first 6 months of the postoperative period . Methods Patients Patients were recruited from the waiting lists of all seven cardiovascular surgeons operating in the Hamilton Health Sciences Corporation surgical center , Hamilton , Ontario , Canada . Each year , approximately 1300 open-heart surgeries are performed in this center . Roughly 60 % of patients awaiting CABG have elective status and are placed on the waiting list . During the time of our study , elective waiting times ranged from 3 weeks to greater than 20 weeks . Approximately 40 % of elective patients are usually awaiting first-time  CABG ( nonvalve replacement ) . Only patients awaiting a first CABG whose surgery date s were at least 10 weeks away were approached to participate in our study . Patients were excluded if they were having combined CABG and valve surgery , if their ejection fractions were less than 0.40 , if they could not attend the exercise classes because of geographic inaccessibility , or if they were unable to participate because of physical limitations . After these inclusion and exclusion criteria were applied , our pool of potential participants was approximately 250 patients per year . We intended to select low-risk patients because it is not common to test an exercise intervention in patients awaiting CABG . Design We design ed a two-group r and omized , controlled trial . Eligible patients were r and omly assigned to 8 weeks of multidimensional preoperative intervention or to usual care . Those assigned to usual care were followed by their primary care physicians , cardiologists , or surgeons . During the waiting period , the intervention group received individualized , prescribed exercise training twice per week in a supervised environment ; education and reinforcement ; and monthly nurse-initiated telephone calls to answer questions and provide reassurance . After surgery , patients in both the treatment and control groups were given the opportunity to join the existing cardiac rehabilitation program ( Appendix ) . Outcomes The primary outcome was postoperative length of hospital stay . Secondary outcomes were peak exercise performance , health-related quality of life , social support , anxiety , and utilization of health care services . Measurements were taken at baseline , 1 week before surgery , 6 to 8 weeks after surgery , and 6 months after surgery . All of the secondary outcome variables were measured at baseline and 1 week before surgery . At 6 weeks and 6 months after surgery , only exercise performance , quality of life , and social support were measured . Determination of Sample Size Sample size was determined by using 19941995 data on length of stay in our surgical center . According to a r and om sample of 20 patients undergoing elective CABG , the mean total length of stay SD was 9.4 3.5 days . On the basis of these data , and accounting for a loss of 10 % to 15 % of patients , we determined that a sample size of 125 patients per group had sufficient power ( 0.8 ) to detect a 1-day reduction in hospital stay ( = 0.05 ) . Procedures The Research Ethics Board of McMaster University ( Hamilton , Ontario ) and the study hospital approved the study . On a weekly basis , staff at each of the surgeon 's offices supplied the names of patients who were scheduled to wait at least 10 weeks for surgery . Patients were telephoned , and the study was explained to them . The recruitment officer was completely c and i d about the r and om assignment and the treatments that would be offered to each group . Within 1 week after giving verbal consent , patients came to the clinic to provide written informed consent . At this visit , we collected complete baseline data and patients underwent an exercise test . Baseline data included demographic information ( age , sex , socioeconomic status , living arrangements , education , and employment status ) ; medical history ; past and present smoking status ; and history of myocardial infa rct ion , angina , congestive heart failure , and diabetes . Baseline data were also collected on anxiety , health-related quality of life , utilization of health care services , and social support . Data later obtained from medical records included total length of hospital stay , length of postoperative stay , number of hours spent in the intensive care unit ( ICU ) before receiving a discharge order , and actual hours spent in the ICU . R and omization and Blinding The study coordinator r and omly assigned patients to study groups by using a concealed r and omization process . A consultant prepared the r and omization schedule , and assignments were sealed in opaque envelopes that were opened in sequence after consent and baseline data were obtained . Patients were not blinded to their group assignments . However , the patients ' physicians ( cardiologists , surgeons , and general practitioners ) were blinded to group assignment and were not informed of it at any point in the study by patients or health care staff . Persons involved in offering the intervention ( nurses , kinesiologists , dietitians ) were aware of the patients ' group assignments but had no role in determining the patients ' readiness for discharge from the ICU or from the hospital ; therefore , they did not directly affect the primary outcome . Assessment of Outcomes Data on length of stay were collected by individual chart review . Total length of stay and total length of ICU stay were easily determined by using admission and discharge date s. However , after discussion with the cardiovascular surgeons before the study began , we realized that total length of ICU stay would misrepresent patients ' postoperative progress . On many occasions , the patient is ready for discharge from the ICU but bed or staffing issues substantially delay his or her actual departure . Therefore , we collected data on length of ICU stay in hours and , more particularly , in hours until order for ICU discharge . This required detailed chart review to locate time in and time out information as well as the time that the physician 's discharge order was given . Although the physicians often did not record the times of their orders , these data were found in nurses ' ICU notes . In approximately 5 % of cases , the data were not retrievable and the mean time until order for discharge was imputed . Exercise performance was measured by using a symptom-limited , upright-cycle ergometer exercise test .  General health-related quality of life was measured by using the Medical Outcomes Study 36-item Short Form Survey ( SF-36 ) ( 13 ) .  Social support was measured by using the  Interpersonal Support Evaluation List  ( 14 ) , and the total scale score was used in analysis . Anxiety was measured with the Spielberger StateTrait Anxiety Inventory ( 15 ) , from which both a trait score and a state anxiety score were computed . The total score from the Health Services Utilization Question naire ( 16 ) was computed and used in the analysis ( Appendix ) . Statistical Analysis All analyses were performed by using the SPSS statistical package ( 17 ) , versions 6.0 and 8.0 ( SPSS , Inc. , Chicago , Illinois ) . We analyzed data on patients whose status was elective from study entry until 1 week before surgery ( n = 220 ) . Data were complete for the primary outcome variables . When a measurement tool did not supply an approach for dealing with missing data , we used an imputation strategy , the hot deck approach ( 18 ) , in which the score from a matched patient in the same group is substituted for the missing score . The defining characteristics for matching patients were age , sex , and number of bypasses required . At the measurement point 6 months after surgery , 78 % of patients returned for all final assessment s. Follow-up to establish vital status was complete for all patients . Data on length of stay are usually positively skewed . Therefore , we selected the MannWhitney test for Objective An investigation into the incidence of post-operative complications after thoracic surgery with  3 different physiotherapy masks . Design A prospect i ve , consecutive , r and omized comparison . Setting Department of Thoracic and Heart Surgery at a University Hospital . The treatments were performed by experienced and specially trained physiotherapists . Patients 160 patients were evaluated . 60 patients undergoing heart surgery , 59 patients having pulmonary resection , and 41 patients with exploratory thoractomy . Interventions In each operative category the patients were treated with one of three face mask systems used in addition to routine chest physiotherapy . These were either continuous positive airway pressure ( CPAP ) , positive expiratory pressure ( PEP ) , or inspiratory resistance — positive expiratory pressure ( IR-PEP ) . Measurements and results Post-operative pulmonary complications were assessed by forced vital capacity ( FVC ) , arterial oxygen tension ( PaO2 ) , and chest X-ray examination , all measured pre-operatively and on the fourth and ninth post-operative day . The patients filled in a question naire expressing their opinion about their mask treatment . There was an equal decrease in FVC , FVC% , and PaO2 , and equal frequency of atelectasis in the 3 mask treatments . More patients with the PEP mask favoured their system than did those with the other 2 systems . Conclusion There was no statistically significant difference between the treatments : continuous positive airway pressure ( CPAP ) , positive expiratory pressure ( PEP ) , and inspiratory resistance — positive expiratory pressure ( IR-PEP ) on post-operative complications . Any of the three treatments may be used as supplement to st and ard chest physiotherapy Abstract Objective . To investigate the efficiency of inspiratory muscle training ( IMT ) on postoperative respiratory muscle strength , functional capacity , quality of life , and psychosocial status in patients with coronary artery bypass graft ( CABG ) surgery . Design . Forty-three patients undergoing CABG surgery were r and omly assigned to the one of two groups . All subjects received usual care . In addition , subjects in the intervention group received IMT training pre- and postoperatively . Pulmonary function testing , six minute walk test ( 6MWT ) , quality of life and psychosocial parameters were assessed preoperatively and the fifth day after the surgery . Results . The mean inspiratory muscle strength increased from 82.64 cmH2O at baseline to 95.45 cmH2O five days postoperatively in the intervention group . The intervention group ( 319.55 ± 72.17 m before and 387.91 ± 65.69 m after surgery ) covered further distance during the 6MWT than usual care ( 355.43 ± 56.08 m before and 357.69 ± 43.42 m after surgery ) . The improvement in quality of life was greater in the intervention group for the dimension of sleep . The anxiety scores were significantly lower in the intervention group than the usual care group . The length of intensive care unit stay was significantly shorter in the intervention group than the usual care group ( p < 0.05 ) . Conclusion . IMT results in faster recovery of inspiratory muscle strength , functional capacity , intensive care unit stay , quality of life and psychosocial status after CABG This is a prospect i ve study of 500 consecutive patients having coronary artery bypass surgery ; mean hospital charge from time of surgery to discharge was + 11,900 + /- 12,700 . Multiple regression analysis was performed using preoperative variables and postoperative complications . No preoperative clinical feature was a significant predictor of higher average charge . Sternal wound infection ( p = 0.0001 ) , respiratory failure ( p = 0.0001 ) and left ventricular failure ( p = 0.017 ) were associated with higher average hospital charge . The absence of any complication predicted a lower average charge , and postoperative death ( 4.4 + /- 4.5 days after surgery ) was also associated with lower average charge . A cost equation was developed : hospital charge equalled $ 11,217 + $ 41,559 of sternal wound infection , + $ 28,756 for respiratory failure , + $ 5,186 for left ventricular failure , - $ 1,798 for no complication and - $ 6,019 for death . Recognition of the influence of complications on charges suggests that low average charges can only be achieved by surgical programs with a low complication rate AIM A variety of chest radiograph abnormalities are recognized after coronary artery bypass grafting ( CABG ) . This study analyzes the appearance of preoperative and postoperative chest radiographs in two groups of patients undergoing myocardial revascularization with or without the use of cardiopulmonary bypass ( CPB ) .  METHODS Chest radiographs ( preoperative and at 1 day , 6 days and 6 to 8 weeks post operatively ) were analyzed according to a detailed protocol in cases of  conventional CABG on CPB ( n=60 ) or off-pump coronary artery bypass ( OPCAB ) ( n=60 ) surgery . On each film 17 different major potential postoperative abnormalities were analyzed . RESULTS Clinical findings were similar in the two groups . Patients undergoing OPCAB surgery  had decreased blood loss , decreased red cell and platelet transfusion , significantly lower intubation time and required less postoperative inotropic support compared with patients undergoing CPB . The CPB group had a significantly higher incidence of left b and atelectasis than the OPCAB group ( 37.6 % vs 17.5 % , p=0.01 ) at 6 days postoperatively . There was no other statistically significant difference in any of the 16 remaining major chest radiograph findings between the two groups . CONCLUSION Although OPCAB surgery is associated with improved clinical outcome compared with conventional CABG surgery , the analysis of postoperative chest radiographs demonstrated only a minor benefit as shown by a reduced degree of left b and atelectasis in the OPCAB group Two hundred patients who had suffered an acute myocardial infa rct ion 4 - 6 weeks before entered a r and omised controlled trial of  exercise treatment  at a community sports centre supervised by a general practitioner . Eighty one per cent of the treatment group continued to exercise until they returned to work and 73 % completed three months ' exercise . There were no serious complications of the exercise course . The prevalence of angina pectoris fell by 10 % in the treatment group but rose by 60 % in the control group . The perceived energy level rose by significantly more in the treatment group than in the controls . The rise in predicted maximum oxygen uptake was significantly greater in the treatment group than in the control group as was the reduction in the double product ( a reflection of myocardial workload ) at peak exercise . Coronary rehabilitation in the community can be both safe and effective Pulmonary complications after cardiac surgery are a leading cause of postoperative morbidity and mortality . Respiratory muscle weakness may contribute to the postoperative pulmonary abnormalities . We hypothesized that : inspiratory muscle strength ( PImax at RV ) and endurance ( PmPeak/PImax ) decrease following  coronary artery bypass grafting ( CABG ) ; that this weakness is associated with impaired pulmonary function tests ( PFT ) , impaired gas exchange and a higher rate of pulmonary complications ; and that prophylactic inspiratory muscle training ( PIMT ) will prevent these changes . 30 c and i date s for CABG , ranging in age from 33 to 79 , were evaluated and r and omized into 2 groups : 15 received PIMT using a threshold trainer for 30 min/day for 1 month before operation , while 15 served as controls and received sham training . There was a significant decrease in respiratory muscle function , PFT , and gas exchange in the control group following CABG , while in the trained group these parameters where similar to those before entering the study . The differences between the groups were statistically significant . In addition , 4 ( 27 % ) in the control group , but only 1 ( 7 % ) in the trained group had postoperative pulmonary complications . We conclude that CABG is followed by significant deterioration in inspiratory muscle function , PFT and arterial blood gases . Decrease in these parameters can be prevented by PIMT , which may also prevent postoperative pulmonary complications Preoperative cardiac surgical teaching done on a preadmission vs postadmission basis did not affect subjects ' perception of importance of preoperative information or preparation . Hospital teaching methods must be examined so that patient learning is individualized and available when the patient is ready to learn . Preoperative teaching on a preadmission basis may also facilitate admission of the cardiac surgical patient the day of surgery , which could shorten the length of stay Background Sometimes a high intrapulmonary shunt occurs after cardiac surgery , and impairment of lung function and oxygenation can persist for 1 week after operation . Animal studies have shown that postoperative shunt can be explained by atelectasis . In this study the authors tried to determine if atelectasis can explain shunt in patients who have had cardiac surgery . Methods Nine patients having coronary artery bypass graft surgery and nine patients having mitral valve surgery were examined using the multiple inert gas elimination technique before and after operation . On the first postoperative day , computed tomography scans were made at three levels of the thorax . Results Before anesthesia , the average shunt was low ( 2 + /‐ 3 % ; range , 0–13 % ) , but on the first postoperative day shunt had increased to 12 + /‐ 6 % ( range , 3–28 % ) . The computed tomography scans showed bilateral dependent densities in all patients but one . The mean area of the densities was 8 + /‐ 8 % ( range , 0–37 % ) of total lung area , corresponding to a calculated fraction of collapsed lung tissue of 20 + /‐ 14 % ( range , 0–59 % ) . In the basal region , the calculated amount of collapsed tissue was 28 + /‐ 19 % ( range , 0–73 % ) . One mitral valve patient was an outlier and had a large shunt both before and after the operation . Conclusions Large atelectasis in the dorsal part of the lungs was found on the first postoperative day after cardiac surgery . However , there was no clear correlation between atelectasis and measured shunt fraction Background In rats , low-frequency electroneuro-stimulation ( ENS ) of the ear afferent vagus endings and bramstem structures via transauricular electro-acupuncture increases the parasympathetic tone of the autonomic nervous system . We examined the effects of ENS applied in the preoperative period in patients with coronary artery disease ( CAD ) who underwent coronary artery bypass grafting operations Methods ENS was performed in a group of 10 patients with CAD who were classified as Canadian Cardiovascular Society class IV before operation . A second group of 10 patients with a similar degree of CAD compnsed a control group . The efficacy of the procedure was evaluated on the basis of improvement in the patient 's clinical course before and after operation . The presence of major inducible stress protein ( HSP 70i ) and the ATP content of the myocardium was determined in atrial tissue ( part of the right heart auricle ) from both groups of patients . Tissue from patients with Wolff-Parkinson-White ( WPW ) syndrome served as a control , non-ischemic , cardiac tissue . Results A course of 10 ENS procedures improved the patients ' preoperative clinical course , producing a rapid reduction in their angina . By the end of the course , the patients no longer developed angina either at rest or after a moderate physical load , and their dependence on treatment with vasodilators had decreased considerably . Atnal tissue from patients with CAD who were treated with ENS was similar to that from patients with WPW in leaking HSP 70i and in ATP content . In contrast , tissue from the control group of patients with CAD contained HSP 70i and had an increased content of ATP . The antianginal effect of neurostimulation lasted for at least 2–3 weeks after completion of the procedures . The postoperative recovery of patients treated with ENS was characterized by stable hemodynamics and sinus rhythm . Conclusion We conclude that ENS had a central vagotonic/sympatholytic influence on the heart , leading to the development of three main effects in patients with CAD : relief of anginal symptoms , diminution of some biochemical myocardial signs of the disease , and an increase in the heart 's tolerance of operative reperfusion damage
target: Evidence derived from small trials suggests that preoperative physical therapy reduces postoperative pulmonary complications ( atelectasis and pneumonia ) and length of hospital stay in patients undergoing elective cardiac surgery .
  There is a lack of evidence that preoperative physical therapy reduces postoperative pneumothorax , prolonged mechanical ventilation or all-cause deaths
background: BACKGROUND After cardiac surgery , physical therapy is a routine procedure delivered with the aim of preventing postoperative pulmonary complications .
  OBJECTIVES To determine if preoperative physical therapy with an exercise component can prevent postoperative pulmonary complications in cardiac surgery patients , and to evaluate which type of patient benefits and which type of physical therapy is most effective .