Inspiratory Muscle Strength as a Determinant of Functional Capacity Early After Coronary Artery Bypass Graft Surgery

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

Prospective, randomized controlled trial.

Setting

Tertiary public hospital in Brazil.

Participants

Men (N=20) after CABG were randomized 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 randomization, clinical and functional characteristics were similar in the 2 groups. Rehabilitation resulted 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±78m) than controls (323±67m). Peak oxygen uptake (Vo₂peak) 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 Vo₂peak during the late postoperative period suggests that inspiratory muscle strength is an important determinant of functional capacity after CABG.     

Impact of Resistance Training in Chronic Obstructive Pulmonary Disease Patients During Periods of Acute Exacerbation

Objective

To evaluate the effects of whole-body resistance training on exercise capacity, health-related quality of life (HRQOL), and muscle strength in patients hospitalized for exacerbation of chronic obstructive pulmonary disease.

Design

Randomized controlled trial.

Setting

University hospital.

Participants

Patients (N=46) were randomized to either a control group (CG) or training group (TG), and 29 patients completed the study.

Intervention

Training consisted of weight-lifting exercises for 6 muscle groups in the upper and lower limbs (2 sets of 8 repetitions each), and the initial load was set at 80% of the 1-repetition maximum load.

Main Outcome Measures

Patients were evaluated on the second day of hospitalization, at hospital discharge, and 30 days postdischarge. Patients were evaluated on the basis of the 6-minute walking distance (6MWD), HRQOL, muscle strength, systemic inflammatory markers, and level of physical activity in daily life (PADL).

Results

The CG showed a reduction in the strength of lower-limb muscles (P<.05) but not in the 6MWD (P>.05). In contrast, patients from the TG improved strength in the lower-limb muscles and 6MWD during and 30 days after hospitalization (P<.05). The TG also improved the impact domain in HRQOL after hospitalization. No improvement in PADL was observed in the TG. Finally, a reduction in the blood levels of inflammatory markers was observed only in the TG after hospitalization.

Conclusions

Our results suggest that resistance training during hospitalization improves the 6MWD, HRQOL, and lower-limb muscle strength, without altering the levels of systemic inflammation. However, future research should explore this intervention in larger randomized trials.     

Influence of Inspiratory Muscle Weakness on Inspiratory Muscle Training Responses in Chronic Heart Failure Patients: A Systematic Review and Meta-Analysis

Objective

To determine whether the impact of inspiratory muscle weakness on inspiratory muscle training (IMT) affects inspiratory function and exercise capacity in chronic heart failure (CHF) patients.

Data Sources

Electronic searches were performed using the Cumulative Index to Nursing and Allied Health Literature, Cochrane Central Register of Controlled Trials, Cochrane Systematic Review, Embase, MEDLINE, and Physiotherapy Evidence Database (PEDro) databases up to August 2013.

Study Selection

Articles were included if participants had CHF and were >18 years old; the design was a randomized controlled trial; intervention was IMT; measurements were of inspiratory muscle function or exercise capacity; and the articles were published in English, Portuguese, or Spanish. Of the 1455 articles identified in the database searches, 9 studies met the inclusion criteria.

Data Extraction

Two independent reviewers selected and extracted information from articles and assessed the quality of the studies using the PEDro scale. The 2 reviewers discussed disagreements until consensus was achieved.

Data Synthesis

Meta-analyses compared IMT with controls/sham for maximal inspiratory pressure, sustained maximal inspiratory pressure, 6-minute walk distance, peak oxygen consumption, and minute ventilation after IMT. Subgroup analyses compared those with and without muscle weakness. CHF with inspiratory muscle weakness showed greater gains in the 6-minute walk distance and peak oxygen consumption compared with those with normative maximal inspiratory pressure. The mean quality analysis score was 7.1, and scores ranged from 6 to 10.

Conclusions

The results emphasize the importance of evaluating the inspiratory muscles to identify patients with CHF and inspiratory muscle weakness; subgroup that showed better results after IMT.     

Body mass index is negatively correlated with respiratory muscle weakness and interleukin-6 production after coronary artery bypass grafting

Purpose

The present study was performed to clarify the relationships between body mass index (BMI), interleukin-6 (IL-6) production, and respiratory muscle weakness in patients undergoing coronary artery bypass grafting (CABG).

Materials and Methods

The correlations among BMI, changes in maximum inspiratory and expiratory pressure (ΔMIP, ΔMEP) on postoperative days (POD) 1 and 7, postoperative IL-6, and rapid turnover proteins (retinol-binding protein, prealbumin, and transferrin) on POD1 were assessed in 154 consecutive patients undergoing elective CABG. The patients were divided into quartiles of BMI, Q1 (BMI, <20.8 kg/m²) to Q4 (BMI, ≥25.25 kg/m²), and compared among groups.

Results

There were significant correlations between ΔMIP and BMI (POD1, r = −0.369; POD7, r = −0.285) and IL-6 (POD1, r = 0.423; POD7, r = 0.431), and between ΔMEP and BMI (POD1, r = −0.252; POD7, r = −0.228) and IL-6 (POD1, r = 0.252; POD7, r = 0.384). Interleukin-6 showed a significant negative correlation with BMI (r = −0.374) and retinol-binding protein (r = −0.382). Interleukin-6 was highest in Q1 and lowest in Q4. Higher BMI indicated greater respiratory muscle strength than lower BMI.

Conclusions

Preoperative BMI is correlated with respiratory muscle strength and cytokine production after CABG. The findings of this study suggest that BMI may be a valuable predictor for respiratory management in CABG patients.     

Preadmission interventions to prevent postoperative complications in older cardiac surgery patients: A systematic review

Objective(s)

The literature on postoperative complications in cardiac surgery patients shows high incidences of postoperative complications such as delirium, depression, pressure ulcer, infection, pulmonary complications and atrial fibrillation. These complications are associated with functional and cognitive decline and a decrease in the quality of life after discharge. Several studies attempted to prevent one or more postoperative complications by preoperative interventions. Here we provide a comprehensive overview of both single and multiple component preadmission interventions designed to prevent postoperative complications.

Methods

We systematically reviewed the literature following the PRISMA statement guidelines.

Results

Of 1335 initial citations, 31 were subjected to critical appraisal. Finally, 23 studies were included, of which we derived a list of interventions that can be applied in the preadmission period to effectively reduce postoperative depression, infection, pulmonary complications, atrial fibrillation, prolonged intensive care unit stay and hospital stay in older elective cardiac surgery patients. No high quality studies were found describing effective interventions to prevent postoperative delirium. We did not find studies specifically targeting the prevention of pressure ulcers in this patient population.

Conclusions

Multi-component approaches that include different single interventions have the strongest effect in preventing postoperative depression, pulmonary complications, prolonged intensive care unit stay and hospital stay. Postoperative infection can be best prevented by disinfection with chlorhexidine combined with immune-enhancing nutritional supplements. Atrial fibrillation might be prevented by ingestion of N-3 polyunsaturated fatty acids. High quality studies are urgently needed to evaluate preadmission preventive strategies to reduce postoperative delirium or pressure ulcers in older elective cardiac surgery patients.     

Preoperative inspiratory muscle training in a patient with lung cancer and comorbid chronic obstructive pulmonary disease and respiratory sarcopenia: A case report

Introduction

Sarcopenia and chronic obstructive pulmonary disease (COPD) are risk factors for postoperative pulmonary complications (PPCs). Preoperative inspiratory muscle weakness is also a risk factor for PPCs. Sarcopenia and COPD are often associated with inspiratory muscle weakness. Respiratory sarcopenia has been defined as the coexistence of whole-body sarcopenia and respiratory muscle weakness. We report our experience with preoperative pulmonary rehabilitation, including inspiratory muscle training (IMT), in a patient with lung cancer and comorbid respiratory sarcopenia and COPD.

Case presentation

A 73-year-old man with squamous cell lung cancer (cStage IA2) was hospitalized for pulmonary rehabilitation before lung resection. He had comorbid severe sarcopenia and COPD (GOLD stage III). He also had inspiratory muscle weakness and a thin diaphragm. We conducted IMT on the patient in addition to aerobic exercise and instruction regarding sputum expectoration for 2 weeks before the surgery. Consequently, his pulmonary function, respiratory muscle strength, and exercise capacity improved. Segmentectomy was performed using video-assisted thoracic surgery. No postoperative complications occurred.

Conclusion

IMT in a patient with lung cancer and comorbid respiratory sarcopenia and COPD resulted in improved respiratory muscle strength and pulmonary function. IMT may have reduced the risk of PPCs by strengthening the respiratory muscles and improving pulmonary function.

     

A Combined Inspiratory and Expiratory Muscle Training Program Improves Respiratory Muscle Strength and Fatigue in Multiple Sclerosis

Objective

To determine the effects of a short-duration, combined (inspiratory and expiratory), progressive resistance respiratory muscle training (RMT) protocol on respiratory muscle strength, fatigue, health-related quality of life, and functional performance in individuals with mild-to-moderate multiple sclerosis (MS).

Design

Quasi-experimental before-after trial.

Setting

University rehabilitation research laboratory.

Participants

Volunteers with MS (N=21) were divided into 2 groups: RMT (n=11; 9 women, 2 men; mean age ± SD, 50.9±5.7y, mean Expanded Disability Status Scale score ± SD, 3.2±1.9) and a control group that did not train (n=10; 7 women, 3 men; mean age ± SD, 56.2±8.8y, mean Expanded Disability Status Scale score ± SD, 4.4±2.1). Expanded Disability Status Scale scores ranged from 1 to ≤6.5. No patients withdrew from the study.

Intervention

Training was a 5-week combined progressive resistance RMT program, 3d/wk, 30 minutes per session.

Main Outcome Measures

The primary outcome measures were maximal inspiratory pressure and expiratory pressure and the Modified Fatigue Impact Scale. All subjects completed secondary measures of pulmonary function, the six-minute walk test, the timed stair climb, the Multiple Sclerosis Self-Efficacy Scale, the Medical Outcomes Study 36-Item Short-Form Health Survey, and the Physical Activity Disability Scale.

Results

Maximal inspiratory pressure and expiratory pressure (mean ± SD) increased 35%±22% (P<.001) and 26%±17% (P<.001), respectively, whereas no changes were noted in the control group (12%±23% and −4%±17%, respectively). RMT improved fatigue (Modified Fatigue Impact Scale, P<.029), with no change or worsening in the control group. No changes were noted in the six-minute walk test, stair climb, Multiple Sclerosis Self-Efficacy Scale, or Physical Activity Disability Scale in the RMT group. The control group had decreases in emotional well-being and general health (Medical Outcomes Study 36-Item Short-Form Health Survey).

Conclusions

A short-duration, combined RMT program improved inspiratory and expiratory muscle strength and reduced fatigue in patients with mild to moderate MS.     

Changes in Pulmonary Function During the Early Years After Inpatient Rehabilitation in Persons With Spinal Cord Injury: A Prospective Cohort Study

Objective

To describe changes in pulmonary function (PF) during the 5 years after inpatient rehabilitation in persons with spinal cord injury (SCI) and to study potential determinants of change.

Design

Prospective cohort study.

Setting

Eight rehabilitation centers with specialized SCI units.

Participants

Persons with SCI (N=180).

Interventions

Not applicable.

Main Outcome Measures

PF was determined by forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV₁) as a percentage of the predicted value, at the start of rehabilitation, at discharge, and 1 and 5 years after discharge from inpatient rehabilitation. The population was divided into 3 subgroups on the basis of whether their PF declined, stabilized, or improved.

Results

FVC improved on average 5.1% over the whole period between discharge of inpatient rehabilitation and 5 years thereafter, but changes differed largely between persons. FVC declined in 14.9% of the population during the first year after discharge. During this year, body mass index, inspiratory muscle strength, change in peak power output, and change in peak oxygen uptake differed significantly between subgroups. FVC declined in 28.3% of the population during the following 4 years, but no differences were found between the subgroups for this period. Subgroups based on changes in FEV₁ differed only with respect to change in peak oxygen uptake the first year after discharge.

Conclusions

In our study, many persons with SCI showed a decline in PF, larger than the normal age-related decline, during the 5 years after inpatient rehabilitation. Results suggest that a decline in PF during the first year after inpatient rehabilitation is associated with higher body mass index, lower inspiratory muscle strength, and declined physical fitness.     

Effects of nephrectomy on respiratory function and quality of life of living donors: a longitudinal study

BACKGROUND:

A living donor transplant improves the survival and quality of life of a transplant patient. However, the impact of transplantation on postoperative lung function and respiratory muscular strength in kidney donors remains unknown.

OBJECTIVE:

To evaluate pulmonary function, respiratory muscle strength, quality of life and the incidence of postoperative pulmonary complications (PPCs) in kidney donors undergoing nephrectomy.

METHOD:

This prospective cohort enrolled 110 consecutive kidney donors undergoing nephrectomy. Subjects underwent pulmonary function (using spirometry) and respiratory muscular strength (using manovacuometry) assessments on the day prior to surgery and 1, 2, 3 and 5 days postoperatively. Quality of life (measured by the SF-36) was evaluated preoperatively and 30 days postoperatively. PPCs were assessed daily by a blinded assessor.

RESULTS:

Donors exhibited a decrease of 27% in forced vital capacity, 58% in maximum inspiratory capacity and 51% in maximum expiratory pressure on the 1^stpostoperative day (p<0.001) but this improved over days 2, 3 and 5 but had not returned to preoperative levels. Patient quality of life was still impaired at 30 days with regards to functional capacity, physical role, pain, vitality and social functioning (p<0.05) but these parameters improved slowly. None of the patients developed PPCs.

CONCLUSION:

Kidney donors submitted to nephrectomy exhibited a reduction in pulmonary function, respiratory muscular strength and quality of life, most of which were improving toward pre-surgical levels.     

Coronary artery bypass graft surgery complications: A review for emergency clinicians

Introduction

Coronary artery bypass graft (CABG) surgery remains a high-risk procedure, and many patients require emergency department (ED) management for complications after surgery.

Changes in exercise capacity,muscle strength,and health-related quality of life in esophageal cancer patients undergoing esophagectomy

Background

Surgery for cancer of the thoracic esophagus is a challenging procedure associated with high morbidity and mortality. Perioperative rehabilitation has been introduced to promote early mobilization of the patients and to prevent postoperative pulmonary complications. The purpose of the present study was to characterize the preoperative functional exercise capacity, muscle strength, anxiety, depression, and health-related quality of life (QOL) in patients with esophageal cancer, and to evaluate the impact of radical esophagectomy on these parameters.

Methods

We performed a retrospective review of 34 consecutive patients with newly diagnosed resectable esophageal cancer who underwent esophagectomy followed by postoperative rehabilitation from January to December 2014. Patients were tested for 6-min walk distance (6MWD), knee-extensor muscle strength, hand grip strength, the Hospital Anxiety and Depression Scale (HADS), and the chronic obstructive pulmonary disease (COPD) assessment test (CAT) before and two weeks after the surgery. Before surgery, the pulmonary function test, and components of the MOS 36-item Short-Form Health Survey (SF-36) Questionnaire for general health were assessed.

Results

The mean age was 67.3?±?8.1 years. The patients were predominantly male (76.4 %), had high rates of smoking history (91.2 %), and squamous cell carcinoma (97.1 %). The predicted value for forced expiratory volume in 1 s was 94.0?±?15.9 %, and 12 patients (35.3 %) had COPD. The clinical stage was 0-I in 12 patients, II in 4 patients, III in 16 patients, and IV in 2 patients. Thirty-one patients (91.2 %) underwent open surgery. At the baseline, components of the SF-36 scores significantly correlated with CAT and HADS scores, and the physical status was significantly poorer in patients with COPD than those without. Comparisons between the preoperative and postoperative values revealed significant decreases in 6MWD, hand grip strength, isometric knee extensor muscle strength, and a significant increase in CAT scores but not in HADS scores after surgery. In multiple regression analysis, decreases in 6MWD after the surgery significantly correlated with the preoperative physical component summary of SF-36.

Conclusions

Our results indicate that surgery remained detrimental to health outcomes at two weeks. Further research should investigate whether prehabilitation would improve the postoperative outcomes, QOL, and physical fitness.

     

Exhaled nitrite/nitrate levels as a marker of respiratory complications after heart valve surgery

Purpose

The purposes of this study are to measure the nitric oxide metabolites nitrite and nitrate (NOx) in the exhaled breath condensates (EBCs) of patients submitted to heart valve surgery and to assess the correlation between NOx levels and postoperative respiratory complications.

Materials and Methods

Exhaled breath condensate and blood samples were collected from each patient during spontaneous breathing preoperatively, during invasive mechanical ventilation in the fourth hour after surgery and 12, 24, 48, and 72 hours after the operation. Nitrite and nitrate levels in the EBC and serum were measured by chemiluminescence.

Results

Thirty-two patients were included in the study. In patients who presented with postoperative respiratory complications, the postoperative levels of NOx were significantly higher in the EBC from the fourth postoperative hour compared with those who experienced uneventful postoperative periods (P = .027). However, the preoperative and postoperative serum levels of NOx were not significantly different in between-group analyses (P = .995).

Conclusion

Our results suggest that the postoperative NOx level in the EBC is an early marker of respiratory complications after heart valve surgery. Additional studies using large cohorts are necessary to corroborate our results and to better define the clinical usefulness of assessing NOx in the EBC after cardiac surgery.     

Effects of Intensive Whole-Body Vibration Training on Muscle Strength and Balance in Adults With Chronic Stroke: A Randomized Controlled Pilot Study

Objectives

To investigate the effects of a 6-week whole body vibration (WBV) training program in patients with chronic stroke.

Design

Randomized controlled pilot trial with 6 weeks' follow-up.

Setting

University hospital.

Participants

Adults with chronic stroke (N=15) were randomly assigned to an intervention (n=7) or a control group (n=8).

Interventions

Supervised, intensive WBV training. The vibration group performed a variety of static and dynamic squat exercises on a vibration platform with vibration amplitudes of 1.7 and 2.5mm and frequencies of 35 and 40Hz. The vibration lasted 30 to 60 seconds, with 5 to 17 repetitions per exercise 3 times weekly for 6 weeks. Participants in the control group continued their usual activities and were not involved in any additional training program.

Main Outcome Measures

The primary outcome variable was the isometric and isokinetic muscle strength of the quadriceps (isokinetic dynamometer). Additionally, hamstrings muscle strength, static and dynamic postural control (dynamic posturography), and muscle spasticity (Ashworth Scale) were assessed.

Results

Compliance with the vibration intervention was excellent, and the participants completed all 18 training sessions. Vibration frequencies of both 35 and 40Hz were well tolerated by the patients, and no adverse effects resulting from the vibration were noted. Overall, the effect of intensive WBV intervention resulted in significant between-group differences in favor of the vibration group only in isometric knee extension strength (knee angle, 60°) (P=.022) after 6 weeks of intervention and in isokinetic knee extension strength (velocity, 240°/s) after a 6-week follow-up period (P=.005), both for the paretic leg. Postural control improved after 6 weeks of vibration in the intervention group when the patients had normal vision and a sway-referenced support surface (P<.05). Muscle spasticity was not affected by vibration (P>.05).

Conclusions

These preliminary results suggest that intensive WBV might potentially be a safe and feasible way to increase some aspect of lower limb muscle strength and postural control in adults with chronic stroke. Further studies should focus on evaluating how the training protocol should be administered to achieve the best possible outcome, as well as comparing this training protocol to other interventions.     

Indocyanine green clearance as an outcome prediction tool in cardiac surgery: A prospective study

Purpose

To evaluate the role of plasma disappearance rate of indocyanine green (PDR-ICG) as an outcome prediction tool in cardiac surgery.

Patients and Methods

One hundred ninety patients undergoing coronary artery bypass grafting, valve surgery or combined procedures were enrolled. PDR-ICG measurements along with standard lab values were performed preoperative and on postoperative days 1, 2, and on discharge from the intensive care unit. Adverse outcomes were defined as prolonged length of stay in the intensive care unit and/or mortality. Two groups were defined according to length of stay in the intensive care unit (≤ 3 days vs > 3 days).

Results

PDR-ICG values differed significantly for all time points between the groups. In a multivariate model, in patients over 65 years with a EuroSCORE below 8.5, a preoperative PDR-ICG value below 12.85%/min was the strongest independent predictor for prolonged intensive care unit stay (> 3 days). A preoperative PDR-ICG value below 8.2%/min was the strongest independent predictor for mortality in a multivariate analysis including age, cardiac function, and EuroSCORE.

Conclusions

In addition to the established scores, PDR-ICG may provide valuable information for the assessment of perioperative morbidity and mortality in cardiac surgery. Pre- and early postoperative measurements may help to identify patients at risk for developing perioperative complications.     

Effect of intraoperative dobutamine on splanchnic tissue perfusion and outcome after Whipple surgery

Purpose

Splanchnic hypoperfusion during abdominal surgery contributes to postoperative gut sepsis and mortality. Dobutamine is an inotrope with vasodilator properties that improve hepatosplanchnic perfusion. The aim of this study was to examine the effect of intraoperative dobutamine infusion during Whipple surgery on splanchnic perfusion, hemodynamic, and overall postoperative outcome.

Methods

Sixty patients were randomly allocated to receive intraoperatively (3 μg/kg per minute or 5 μg/kg per minute) doses of dobutamine or saline. Baseline measurements included hemodynamic parameters, gastric tonometric parameters, and arterial and mixed venous gases. These patients had a follow-up for development for in-hospital morbidity and mortality.

Results

Intraoperative use of dobutamine increased oxygen-derived parameters as evidenced by increased mixed venous oxygen saturation. Tonometered gastric mucosal pH, a surrogate for splanchnic perfusion, increased in patients who received intraoperative dobutamine. Patients in the dobutamine groups demonstrated significant higher heart rates, premature ventricular contraction arrhythmias, and electrocardiographic signs of ischemia. Mean arterial blood pressure demonstrated no significant difference among groups. The overall incidence of postoperative complications was higher in control group 70 % vs 20% to 40% in dobutamine groups.

Conclusion

Intraoperative use of dobutamine improved global oxygen delivery, splanchnic perfusion, and postoperative outcome after Whipple surgery. These findings may be of clinical importance when the therapeutic goal is to improve gut perfusion.     

Long-Term Impact of Strength Training on Muscle Strength Characteristics in Older Adults

Objective

To evaluate the long-term preventive impact of strength training on muscle performance in older adults.

Design

A 7-year follow-up on a 1-year randomized controlled trial comparing the effects of combined resistance training and aerobic training and whole-body vibration training on muscle performance.

Setting

University training center.

Participants

Men and women (N=83; control [CON] group, n=27; strength-training intervention [INT] group, n=56) between 60 and 80 years of age.

Interventions

The INT group exercised 3 times weekly during 1 year, performing a combined resistance training and aerobic training program or a whole-body vibration training program. The former training program was designed according to American College of Sports Medicine guidelines. The whole-body vibration training program included unloaded static and dynamic leg exercises on a vibration platform. The CON group did not participate in any training program.

Main Outcome Measures

Static strength (STAT), dynamic strength at 60°/s (DYN₆₀) and at 240°/s (DYN₂₄₀), speed of movement at 20% (S₂₀).

Results

From baseline to postintervention, muscle performance did not change in the CON group, except for S₂₀ (+6.55%±2.88%, P<.001). One year of strength training increased (P≤.001) STAT (+11.46%±1.86%), DYN₆₀ (+6.96%±1.65%), DYN₂₄₀ (+9.25%±1.68%), and S₂₀ (+7.73%±2.19%) in the INT group. Between baseline and follow-up, muscle performance decreased (P<.001) in both groups. However, STAT and DYN₆₀ showed a significantly lower loss in the INT group (−8.65%±2.35% and −7.10%±2.38%, respectively) compared with the CON group (−16.47%±2.69% and −15.08%±2.27%, respectively). This positive impact might be due to the preservation of the training-induced gains, given the similar annual decline rates in both groups from postintervention to follow-up. Additionally, in trained participants, aging seems to impact velocity-dependent strength and power more compared with basic strength, as the total losses in DYN₂₄₀ (CON, −15.93%±2.64%; INT, −11.39%±1.95%) and S₂₀ (CON, −14.39%±2.10%; INT, −13.16%±1.72%) did not differ significantly between the groups.

Conclusions

A 1-year strength-training intervention results in an improved muscle performance in older adults 7 years after their enrollment in the intervention. However, an extensive exercise program cannot attenuate the age-related decline once the intervention stops.     

Central venous pressure after coronary artery bypass surgery: Does it predict postoperative mortality or renal failure?

Objective

Although hemodynamic monitoring is often performed after coronary artery bypass grafting (CABG), the role of monitoring postoperative central venous pressure (CVP) measurement as a predictor of clinical outcomes is unknown. As such, this study tests the hypothesis that postoperative CVP is predictive of operative mortality or renal failure.

Methods

This is an observational cohort study of detailed clinical data from 2390 randomly selected patients undergoing high-risk CABG or CABG/valve at 55 hospitals participating in the Society of Thoracic Surgeons' National Cardiac Surgery Database 2004-2005. Eligible patients underwent elective/urgent CABG with an ejection fraction less than 40% or elective/urgent CABG at 65 years or older with diabetes or a glomerular filtration rate less than 60 mL/min per 1.73 m². The exposure of interest is CVP monitoring in the intensive care unit after adult cardiac surgery. The primary outcome measure was correlation between postoperative CVP and inhospital/30-day mortality and renal failure, assessed as a continuous variable, both unadjusted and after adjusting for important clinical factors using logistic regression modeling.

Results

Mean age was 72 years, 54% of patients had diabetes mellitus, 49% were urgent procedures, and mean cardiopulmonary bypass time was 105 minutes. Patients' CVP 6 hours postoperation was strongly associated with inhospital and 30-day mortality: odds ratio (OR) of 1.5 (95% confidence interval [CI], 1.23-1.87) for every 5-mm Hg increase in CVP; P < .0001. This association remained significant after risk adjustment: adjusted OR of 1.44 (95% CI, 1.10-1.89); P < .01. A model adjusting for cardiac index also revealed increased incidence of mortality or renal failure: adjusted OR of 1.5 (95% CI, 1.28-1.86) for every 5-mm Hg increase in CVP; P < .0001.

Conclusions

Patients' CVP at 6 hours after CABG surgery was highly predictive of operative mortality or renal failure, independent of cardiac index and other important clinical variables. Future studies will need to assess whether interventions guided by postoperative CVP can improve patient outcomes.     

Effects of inspiratory muscle training in children with cerebral palsy: a randomized controlled trial

Background

Respiratory muscle weakness and its relation to other impairments in children with cerebral palsy (CP) have been shown in the latest studies. The effects of inspiratory muscle training (IMT) in this population have not been comprehensively investigated so far.