Kelly M. Smith

Hypotension following mild bouts of resistance exercise and submaximal dynamic exercise

Abstract Our purposes were (1) to examine resting arterial blood pressure following an acute bout of resistance exercise and submaximal dynamic exercise, (2) to examine the effects of these exercises on the plasma concentrations of atrial natriuretic peptide ([ANP]), and (3) to evaluate the potential relationship between [ANP] and post-exercise blood pressure. Thirteen males [24.3 ± (2.4) years] performed 15 min of unilateral leg press exercise (65% of their one-repetition maximum) and, 1 week later, ≈15 min of cycle ergometry (at 65% of their maximum oxygen consumption). Intra-arterial pressure was monitored during exercise and for 1 h post-exercise. Arterial blood was drawn at rest, during exercise and at intervals up to 60 min post-exercise for analysis of haematocrit and [αANP]. No differences occurred in blood pressure between trials, but significant decrements occurred following exercise in both trials. Systolic pressure was ≈20 mmHg lower than before exercise after 10 min, and mean pressure was ≈7 mmHg lower from 30 min onwards. Only slight (non-significant) elevations in [αANP] were detected immediately following exercise, with the concentrations declining to pre-exercise values by 5 min post-exercise. We conclude that post-exercise hypotension occurs following acute bouts of either resistance or submaximal dynamic exercise and, in this investigation, that this decreased blood pressure was not directly related to the release of αANP.

Changes in exercise capacity and lipids after clinic versus home-based aerobic training in coronary artery bypass graft surgery patients.

PURPOSE Despite the documented benefits of participating in rehabilitation programs, access to cardiac rehabilitation is limited for a large number of people with coronary artery disease (CAD). There is potential to increase participation in exercise training if home-based exercise were a viable option. METHODS We conducted a retrospective database review of 1,042 patients who took part in exercise rehabilitation following coronary artery bypass graft surgery (CABGS) between 1992 and 1998. Of these, 713 patients took part in supervised exercise, and 329 were in an unsupervised, home-based group. All exercise protocols were based upon American College of Sports Medicine guidelines, and patients in both groups received exercise prescriptions that were similar in intensity, frequency, and duration. RESULTS There were no differences between groups at baseline. Following 6 months of exercise training, there were substantial improvements in peak VO2, peak workload, and peak MET levels in both the supervised and unsupervised groups (P < 0.0001). Patients in the supervised group had significant improvements in both LDL and HDL-cholesterol, whereas the home-based group showed improvement in HDL-cholesterol only. When analyzed by sex, men performed better than women for all measures of exercise capacity; however, women in both groups showed approximate 20% improvements (P < 0.05) in exercise capacity as well as improvements in HDL-cholesterol. CONCLUSION Stable post CABGS patients who receive a detailed exercise prescription to follow at home do as well as those in supervised rehabilitation.

The Effect of Early Education on Patient Anxiety While Waiting for Elective Cardiac Catheterization

Background: A supply–demand mismatch with respect to cardiac catheterization (CATH) often results in patients experiencing waiting times that vary from a few weeks to several months. Long delays can impose both physical and psychological distress for patients. Purpose: The purpose of this study was to examine the effect of a psychoeducational nursing intervention at the beginning of the waiting period on patient anxiety during the waiting time for elective CATH. Methods: This was a 2-group randomized controlled trial. Intervention patients received a nurse-delivered, detailed information/education session within 2 weeks of being placed on the waiting list for elective CATH. Control group patients received usual care. Results: The mean waiting time for CATH was 13.4±7.2 weeks, which did not differ between groups (P=0.509). Anxiety increased in both groups over the waiting time (P=0.028). Health-related quality of life deteriorated over the waiting time in both groups (P<0.05). On a visual analogue scale, there was a significant difference (P=0.002) between the intervention (4.0±2.7) and control (5.2±3.0) groups in self-reported anxiety 2 weeks prior to CATH. Conclusions: The waiting period prior to elective CATH has a negative impact on patients’ perceived anxiety and quality of life and a simple intervention, provided at the beginning of the waiting period, may positively affect the experience of waiting.

Responding to patient safety incidents: the “seven pillars”

Background Although acknowledged to be an ethical imperative for providers, disclosure following patient safety incidents remains the exception. The appropriate response to a patient safety incident and the disclosure of medical errors are neither easy nor obvious. An inadequate response to patient harm or an inappropriate disclosure may frustrate practitioners, dent their professional reputation, and alienate patients. Methods The authors have presented a descriptive study on the comprehensive process for responding to patient safety incidents, including the disclosure of medical errors adopted at a large, urban tertiary care centre in the United States. Results In the first two years post-implementation, the “seven pillars” process has led to more than 2,000 incident reports annually, prompted more than 100 investigations with root cause analysis, translated into close to 200 system improvements and served as the foundation of almost 106 disclosure conversations and 20 full disclosures of inappropriate or unreasonable care causing harm to patients. Conclusions Adopting a policy of transparency represents a major shift in organisational focus and may take several years to implement. In our experience, the ability to rapidly learn from, respond to, and modify practices based on investigation to improve the safety and quality of patient care is grounded in transparency.

Predicting cardiac rehabilitation enrollment: the role of automatic physician referral.

Background Despite the established benefits of cardiac rehabilitation, evidence suggests referral to, and subsequent enrollment in, cardiac rehabilitation following a coronary event remains low (10-25%). The aim of this study was to identify predictors of attendance to cardiac rehabilitation intake and subsequent enrollment in rehabilitation after coronary artery bypass graft surgery within the framework of an automatic referral system. Design and methods We conducted a historic prospective study of patients who underwent coronary artery bypass graft surgery between 1 April 1996 and 31 March 2000 and lived within the geographic referral area of a multi-disciplinary cardiac rehabilitation center in central-south Ontario, Canada. Coronary artery bypass graft surgery patients are automatically referred to cardiac rehabilitation at the time of hospital discharge. Consecutive health records of eligible patients were reviewed for medical history, cardiac risk factor profiles, and evidence of cardiac rehabilitation intake attendance and enrolment. Results A total of 3536 patients met eligibility criteria. Patients were predominantly male (79.1%), approximately 64 years of age, living with a spouse or a partner, English-speaking, retired and had multiple cardiac risk factors. Of eligible patients, 2121 (60.0%) attended the cardiac rehabilitation intake appointment. Of patients who attended cardiac rehabilitation intake 1463 (69%) enrolled in at least one cardiac rehabilitation service, based on their risk factor profile. Selected cardiac rehabilitation services were exercise training (n = 1287; 88%), nutrition counseling (n = 571; 39.0%), nursing care (n = 546; 37.3%), and psychological intervention (n = 223; 15.2%). Conclusions An institutionalized, physician-endorsed system of automatic referral to cardiac rehabilitation resulted in higher rates of cardiac rehabilitation intake and enrollment following coronary artery bypass graft surgery than previously reported and should be adopted for all cardiac populations.

Six-year follow-up of a randomised controlled trial examining hospital versus home-based exercise training after coronary artery bypass graft surgery

Objective To compare the long-term effectiveness of hospital versus telephone-monitored home-based exercise training during cardiac rehabilitation (CR) on exercise capacity and habitual physical activity. Design Six-year follow-up of patients who participated in a randomised controlled trial of hospital versus monitored home-based exercise training during CR after coronary artery bypass graft surgery. Setting Outpatient CR centre in Central-South Ontario, Canada. Participants 196 Patients who participated in the original randomised controlled trial and who attended an evaluation 1 year after CR. Interventions 6 months of home or hospital-based exercise training during CR. Main outcome measures Peak oxygen uptake (peak Vo2), Physical Activity Scale in the Elderly (PASE) to assess habitual activity, semi-structured interviews to assess vital status, demographic and descriptive information. Results Of the 196 eligible patients, 144 (75.5%; 74 Hospital, 70 Home) were available for participation. Patients were predominantly male (n=120; 83.3%) aged 70±9.5 years. Clinical and sociodemographic outcomes were similar in both groups. While exercise performance declined over time, there were significant between-group differences in peak Vo2 (1506±418 ml/min vs 1393±341 ml/min; p=0.017) and PASE scores (166.7±90.2 vs 139.7±66.5; p=0.001) at 6-year follow-up in favour of the home group. Conclusions Home and hospital-based exercise training maintained exercise capacity above pre-CR levels 6 years after CR. Exercise training initiated in the home environment in low-risk patients undergoing coronary artery bypass graft surgery conferred greater long-term benefit on Vo2 and persistent physical activity compared with traditional hospital-based CR.

Economic evaluation of the MEDENOX trial: A canadian perspective

OBJECTIVE To perform an economic evaluation of the Prophylaxis in Medical Patients with Enoxaparin (MEDENOX) trial from a Canadian perspective. METHOD Using a decision tree model, cost effectiveness analysis was carried out to compare the costs and consequences of thromboprophylaxis using enoxaparin 40 mg with placebo in tertiary and community settings. From a third party payers perspective, the model calculated the expected rate of symptomatic venous thromboembolism (VTE), and the total expected cost of prophylaxis and VTE management, including inpatient and outpatient treatment, professional fees and long term therapy. Data were derived directly from the MEDENOX trial. Costs are direct medical costs in year 2000 Canadian dollars. RESULTS In a tertiary setting in which the estimated inpatient to outpatient deep vein thrombosis treatment ratio was 10%:90%, the total expected cost per patient was 64 dollars in the enoxaparin group and 62 dollars in the placebo group. The expected symptomatic VTE rates were 0.8% and 3.1% in the enoxaparin and placebo groups, respectively. The incremental cost effectiveness of enoxaparin 40 mg versus placebo was 87 dollars/VTE avoided. In a community hospital setting (with a 50%:50% inpatient to outpatient deep vein thrombosis treatment ratio), the total expected cost per patient was 68 dollars in the enoxaparin group compared with 72 dollars in the placebo group, indicating that prophylaxis with enoxaparin 40 mg was cost saving. The model was sensitive to the inpatient to outpatient ratio. However, within each setting, the results were not sensitive to changes in key variables. CONCLUSION For patients hospitalized for acute respiratory failure, congestive heart failure or acute infectious disease and who are at moderate risk of developing VTE, thromboprophylaxis with enoxaparin 40 mg daily is a cost effective strategy in both tertiary and community settings.

The effect of oxygenator membranes on blood: a comparison of two oxygenators in open-heart surgery

Open-heart surgery (OHS) requires cardiopulmonary bypass (CPB) in most patients. Membrane oxygenators are a critical component of the CPB system. Despite advancements in CPB technology, injury to blood components during CPB still occurs and may result in complications after surgery. The purpose of the present study was to evaluate the performance of the Medtronic Affinity NT® with Trillium coating and the Cobe Optima XP® oxygenators and compare their influence on blood components. Two hundred and fifty-six male and female patients scheduled for urgent or elective cardiac surgery with CPB were randomly assigned to either the Affinity NT or the Optima XP oxygenators. Outcomes included platelets, hemoglobin, leukocyte counts, and O2 transfer, measured preoperatively and at 15, 45 and 75 min of CPB time. Blood loss was measured at six and 12 hours postoperatively. A modified intention-to-treat analysis was conducted. The two groups were similar for age, sex, height, weight, body surface area, and blood components at baseline. There were no differences between the Affinity NT and Optima XP for any outcome measure, although a significant change with time was seen in platelets, hemoglobin, hematocrit and leukocytes, as well as O2transfer for both groups (p <0.001). The Affinity NT oxygenator had a significantly lower difference in pressure across the membrane (p <0.001) compared with the Optima XP. In conclusion, the two oxygenators performed similarly with respect to their impact on blood components, O2transfer, and blood loss postoperatively during OHS with CPB. The Affinity NT had the smaller transmembrane pressure drop of the two.