Erik H. Hulzebos

Preoperative physical therapy for elective cardiac surgery patients

BACKGROUNDnAfter cardiac surgery, physical therapy is a routine procedure delivered with the aim of preventing postoperative pulmonary complications.nnnOBJECTIVESnTo 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.nnnSEARCH METHODSnSearches were run on the Cochrane Central Register of Controlled Trials (CENTRAL) on the Cochrane Library (2011, Issue 12 ); MEDLINE (1966 to 12 December 2011); EMBASE (1980 to week 49, 2011); the Physical Therapy Evidence Database (PEDro) (to 12 December 2011) and CINAHL (1982 to 12 December 2011).nnnSELECTION CRITERIAnRandomised controlled trials or quasi-randomised trials comparing preoperative physical therapy with no preoperative physical therapy or sham therapy in adult patients undergoing elective cardiac surgery.nnnDATA COLLECTION AND ANALYSISnData were collected on the type of study, participants, treatments used, primary outcomes (postoperative pulmonary complications grade 2 to 4: atelectasis, pneumonia, pneumothorax, mechanical ventilation > 48 hours, all-cause death, adverse events) and secondary outcomes (length of hospital stay, physical function measures, health-related quality of life, respiratory death, costs). Data were extracted by one review author and checked by a second review author. Review Manager 5.1 software was used for the analysis.nnnMAIN RESULTSnEight randomised controlled trials with 856 patients were included. Three studies used a mixed intervention (including either aerobic exercises or breathing exercises); five studies used inspiratory muscle training. Only one study used sham training in the controls. Patients that received preoperative physical therapy had a reduced risk of postoperative atelectasis (four studies including 379 participants, relative risk (RR) 0.52; 95% CI 0.32 to 0.87; P = 0.01) and pneumonia (five studies including 448 participants, RR 0.45; 95% CI 0.24 to 0.83; P = 0.01) but not of pneumothorax (one study with 45 participants, RR 0.12; 95% CI 0.01 to 2.11; P = 0.15) or mechanical ventilation for > 48 hours after surgery (two studies with 306 participants, RR 0.55; 95% CI 0.03 to 9.20; P = 0.68). Postoperative death from all causes did not differ between groups (three studies with 552 participants, RR 0.66; 95% CI 0.02 to 18.48; P = 0.81). Adverse events were not detected in the three studies that reported on them. The length of postoperative hospital stay was significantly shorter in experimental patients versus controls (three studies with 347 participants, mean difference -3.21 days; 95% CI -5.73 to -0.69; P = 0.01). One study reported a reduced physical function measure on the six-minute walking test in experimental patients compared to controls. One other study reported a better health-related quality of life in experimental patients compared to controls. Postoperative death from respiratory causes did not differ between groups (one study with 276 participants, RR 0.14; 95% CI 0.01 to 2.70; P = 0.19). Cost data were not reported on.nnnAUTHORS CONCLUSIONSnEvidence 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.

Merits of exercise therapy before and after major surgery

Purpose of review Advances in medical care have led to an increasing elderly population. Elderly individuals should be able to participate in society as long as possible. However, with an increasing age their adaptive capacity gradually decreases, specially before and after major life events (like hospitalization and surgery) making them vulnerable to reduced functioning and societal participation. Therapeutic exercise before and after surgery might augment the postoperative outcomes by improving functional status and reducing the complication and mortality rate. Recent findings There is high quality evidence that preoperative exercise in patients scheduled for cardiovascular surgery is well tolerated and effective. Moreover, there is circumstantial evidence suggesting preoperative exercise for thoracic, abdominal and major joint replacement surgery is effective, provided that this is offered to the high-risk patients. Postoperative exercise should be initiated as soon as possible after surgery according to fast-track or enhanced recovery after surgery principles. Summary The perioperative exercise training protocol known under the name ‘Better in, Better out’ could be implemented in clinical care for the vulnerable group of patients scheduled for major elective surgery who are at risk for prolonged hospitalization, complications and/or death. Future research should aim to include this at-risk group, evaluate perioperative high-intensity exercise interventions and conduct adequately powered trials.

The oxygen uptake efficiency slope: what do we know?

PURPOSE: To summarize what is currently known about the oxygen uptake efficiency slope (OUES) as an objective and independent submaximal measure of cardiorespiratory fitness in health and disease. METHODS: A literature search was performed within the following electronic databases—pubmed, cochrane library, embase, web of science, CINAHL, psycINFO, Scopus, and MEDLINE—using the search terms “OUES,” “oxygen uptake efficiency slope,” and “ventilatory efficiency.” The search identified 51 articles. Selection, evaluation, and data extraction were accomplished independently by 2 authors. RESULTS: Twenty-four studies satisfied all inclusion criteria: 17 cross-sectional studies and 7 intervention studies. The results indicated that the OUES is relatively independent of exercise intensity, correlates highly with other exercise parameters, appears to have discriminative value, and is sensitive to the effects of physical training in patients with cardiac disease. Oxygen uptake efficiency slope values are considerably influenced by anthropometric variables and show large interindividual variation. CONCLUSION: Oxygen uptake efficiency slope is an independent and reproducible measure of cardiorespiratory function that does not require maximal exercise. It greatly reduces test variability because of motivational and subjective factors and is reliable and easily determinable in all subjects. Although OUES appears not interchangeable with maximal parameters of cardiopulmonary function, it seems to be a useful submaximal alternative in subjects unable to perform maximal exercise.

Exercise limitation in patients with Fontan circulation: A review

The aim of the current literature study was to perform a literature review of the factors contributing to exercise limitation and physiological response to exercise in patients with Fontan circulation. In patients with Fontan circulation, peak oxygen uptake ranged from about 14.4 to 32.3 ml/min/kg, and showed a slowed acceleration in the kinetics of oxygen uptake at the onset of exercise. Peak heart rate during exercise was decreased to an average of 153 ± 10 bpm and arterial oxygen saturation was also decreased at peak exercise, with an average of 89.5 ± 1.94%. Cardiac output was subnormal, owing to reduced stroke volume, heart rate response and affected pulmonary venous return. Ventilatory anaerobic threshold was below normal values. Moreover, the ventilatory equivalent for carbon dioxide was found to be higher. Patients with Fontan circulation possess a unique physiological response to exercise. Although there is a wide range in exercise capacity among patients, all patients have reduced tolerance to exercise. Cardiac, pulmonary, and muscular factors might play a role in reduced exercise capacity and this distinct response to exercise.

Making the elderly fit for surgery

1University Children’s Hospital and Medical Centre Utrecht, Child and Development and Exercise Centre, University Medical Centre Utrecht, PO Box 85090, 3508 AB Utrecht, and 2Department of Physiotherapy, Physical Functioning in Chronicity, School for Public Health and Primary Care (CAPHRI), Maastricht University, Maastricht, and Health∼Holland (Topsector Life Sciences and Health), The Hague, The Netherlands (e-mail: h.hulzebos@umcutrecht.nl)

Prediction of Mortality in Adolescents with Cystic Fibrosis

INTRODUCTIONnLung function, nutritional status, and parameters of exercise capacity are known predictors of mortality in patients with cystic fibrosis (CF). The aim of the current study was to use these important parameters to develop a multivariate model to predict mortality in adolescent patients with CF.nnnMETHODSnA total of 127 adolescents with CF (57 girls) with a mean age of 12.7 ± 0.9 yr and a mean percentage of predicted forced expired volume in 1 s (FEV1% predicted) of 77.7% ± 15.6% were included. Cardiopulmonary exercise testing-derived parameters, nutritional status, and resting lung functions were dichotomized according to the criterion value determined using receiver operating characteristic curves. Body mass index (BMI), FEV1%predicted, predicted peak oxygen uptake corrected for body weight (VO2 peak/kg%predicted), peak minute ventilation (VE peak), peak VE/VO2, peak VE/VCO2, and breathing reserve were included in a multivariate model. The Cox proportional hazards model was used to determine the combination of parameters that best predicted mortality and/or lung transplantation.nnnRESULTSnThe mean duration of follow-up was 7.5 ± 2.7 yr, during which, nine of the 127 patients (7.1%) died and six (4.7%) underwent lung transplantation. Mortality in this population was best predicted by the model that included FEV1%predicted (hazard ratio, 17.13; 95% confidence interval (CI), 3.76-78.06), peak VE/VO2 (hazard ratio, 5.92; 95% CI, 1.27-27.63), and BMI (hazard ratio, 5.54; 95% CI, 1.82-16.83).nnnCONCLUSIONSnThe currently developed model consisting of BMI, FEV1%predicted, and VE/VO2 is a strong predictor of mortality rate in adolescents with CF. This prediction equation may be useful in clinical practice to detect patients with a high risk of mortality and to provide them with additional therapy earlier.

Effect of Inspiratory Muscle Training Before Cardiac Surgery in Routine Care

Background Inspiratory muscle training (IMT) before cardiac surgery has proved to be a promising intervention to reduce postoperative pneumonia in a randomized controlled trial setting. Effects of IMT in routine care have not been reported. Objective The purpose of this study was to investigate the effect of IMT before cardiac surgery on postoperative pneumonia in routine care at a Dutch university medical center using propensity scoring. Design This was an observational cohort study. Methods All candidates for cardiac surgery were preoperatively stratified by a physical therapist for low risk or high risk for postoperative pulmonary complications. Patients at high risk either engaged in an unsupervised IMT program (20 minutes a day) at home for at least 2 weeks before surgery (group 1) or received usual care (no IMT) (group 2). Results in terms of outcome measures were adjusted with propensity scores to reduce bias caused by nonrandom treatment assignment. Results The results showed that of the 94 patients at high risk in group 1, 1 patient (1.1%) developed a postoperative pneumonia. In group 2, 8 out of the 252 patients at high risk (3.2%) developed this pulmonary complication (adjusted odds ratio=0.34, 95% confidence interval=0.04–3.38). No significant differences were found regarding median (25th–75th percentile) ventilation time (7 [5–9] hours versus 7 [5–10] hours), length of stay in the intensive care unit (23 [21–24] hours versus 23 [21–25] hours), or total postoperative length of stay (7 [6–11] days versus 7 [5–9] days). Limitations The most important limitations of this study were confounding, incomplete data collection, and a low incidence of the primary outcome. Conclusions Propensity scoring is believed to be a valuable tool of great potential interest to researchers in the field of observational studies. Whether IMT in routine care resulted in less postoperative pneumonia cannot be concluded.

Exercise Stress Testing in Children with Metabolic or Neuromuscular Disorders

The role of exercise as a diagnostic or therapeutic tool in patients with a metabolic disease (MD) or neuromuscular disorder (NMD) is relatively underresearched. In this paper we describe the metabolic profiles during exercise in 13 children (9 boys, 4 girls, age 5–15 yrs) with a diagnosed MD or NMD. Graded cardiopulmonary exercise tests and/or a 90-min prolonged submaximal exercise test were performed. During exercise, respiratory gas-exchange and heart rate were monitored; blood and urine samples were collected for biochemical analysis at set time points. Several characteristics in our patient group were observed, which reflected the differences in pathophysiology of the various disorders. Metabolic profiles during exercises CPET and PXT seem helpful in the evaluation of patients with a MD or NMD.

Relationship between lung function and Modified Shuttle Test performance in adult patients with cystic fibrosis: a cross-sectional, retrospective study

OBJECTIVESnTo investigate the relationship between lung function and exercise capacity in adults with cystic fibrosis (CF), and to develop a CF-specific equation to predict Modified Shuttle Test (MST) performance from baseline data.nnnDESIGNnCross-sectional, retrospective study.nnnSETTINGnAdult CF centre.nnnPARTICIPANTSnOne hundred and twenty-seven patients with CF [61 male; mean age 25 years (range 17 to 52 years), mean forced expiratory volume in 1second (FEV1) 56% predicted (range 15 to 124%)].nnnMAIN OUTCOME MEASURESnMST and FEV1.nnnRESULTSnOverall, a moderate-to-good relationship was found between lung function and MST performance (walking distance vs FEV1% predicted: r=0.64, P=0.01). This relationship between FEV1 and MST shows an obvious threshold at an FEV1 of 67% predicted. Above this threshold, no significant association was observed between FEV1 and MST performance. However, a strong relationship (MST vs FEV1% predicted: r≥0.74, P<0.01 for men and r=0.79, P<0.01 for women) was found below an FEV1 of 67% predicted.nnnCONCLUSIONSnThis study suggests that a strong association exists between lung function (FEV1% predicted) and MST (walking distance) in adult patients with moderate-to-severe CF (FEV1<67% predicted). A reference equation for MST performance was developed for those patients with FEV1 ≤67% predicted, providing a tool to make an a-priori prediction of MST walking distance.

Response profiles of oxygen uptake efficiency during exercise in healthy children

Background Oxygen uptake efficiency (OUE), the relation between oxygen uptake (VO2) and minute ventilation (VE), differs between healthy children and children with heart disease. This study aimed to investigate the normal response profiles of OUE during a progressive cardiopulmonary exercise test. Design: Cross-sectional. Methods Healthy children between eight and 19 years of age (114 boys and 100 girls, meanu2009±u2009SD age 12.7u2009±u20092.8 years) performed a maximal cardiopulmonary exercise test. Peak VO2 (VO2peak), ventilatory threshold and peak VE were determined. OUE was determined by the OUE plateau (OUEP), OUE at the ventilatory threshold (OUE@VT) and OUE slope (OUES). Results OUEP (42.4u2009±u20094.6) and OUE@VT (41.9u2009±u20094.7) were similar and less variable than OUES (2138u2009±u2009703). OUEP correlated strongly with OUE@VT (ru2009=u20090.974); however, OUEP was weak-to-moderately correlated with VO2peak (ru2009=u20090.646), the ventilatory threshold (ru2009=u20090.548) and OUES (ru2009=u20090.589). OUES correlated strongly with VO2peak (ru2009=u20090.948) and the ventilatory threshold (ru2009=u20090.856). Reference centiles for OUEP show an almost linear increase from about 37 in eight-year olds to about 47 in 18-year olds, with no sex-difference. OUES increased from about 1400 in eight-year-old boys to approximately 3500 in 18-year-old boys. OUES increased from roughly 1250 in eight-year-old girls to about 2650 in 18-year-old girls. Conclusions This study provides sex- and age-related normative values for both OUEP and OUES, which facilitates the interpretation of OUE in children. OUEP and OUES are objective and non-invasive cardiopulmonary exercise test parameters which do not require a maximal effort and might be indicative of cardiorespiratory function during exercise.