Cardiopulmonary exercise testing in the evaluation of liver disease in adults who have had the Fontan operation.

BACKGROUND: Liver disease (LD) is a long-term complication in patients with a single ventricle who have had the Fontan operation. A decline in cardiopulmonary exercise testing (CPET) variables is associated with increased risk of hospitalization, but its association with LD is unknown. AIM: To determine the association between CPET variables and LD in adults who have had the Fontan operation. METHODS: We retrospectively reviewed the medical records from two tertiary institutions. RESULTS: We identified 114 adults (≥18 years; mean 30.9±7.4 years) who had undergone the Fontan operation: 56% were women; 63% had total cavopulmonary connection; 66% had New York Heart Association (NYHA) class I status; 42% had arrhythmias; 22% had systemic right ventricle; and 35% had ventricular dysfunction. Of 81 patients with liver-imaging data, 41% had LD (i.e. imaging evidence of cirrhosis, with or without portal hypertension, splenomegaly or varices). There were no differences in clinical or echocardiographic variables between those with and without LD. Among the 58 patients with CPET data, mean peak oxygen consumption (VO2) was 18.6±5.7mL/kg/min, per-cent-predicted peak VO2 was 53.9±15.5%, peak oxygen pulse was 9.3±2.9mL/beat and per-cent-predicted peak oxygen pulse was 82.6±21.5%. Of the 44 patients with liver and CPET data, each standard deviation decrease in per-cent-predicted peak VO2 (16%) and per-cent-predicted peak oxygen pulse (22%) was associated with a 2.3-fold increase in the odds of LD, after adjusting for NYHA, institution and Fontan type (P=0.04). Similarly, each standard deviation decrease in per-cent-predicted peak VO2 and oxygen pulse was associated with an estimated 5.9-year and 4.9-year earlier onset of LD, respectively (P>0.05). CONCLUSIONS: Decline in per-cent-predicted peak VO2 and oxygen pulse was associated with increased odds of LD in adults who had undergone the Fontan operation. Our study supports more rapid hepatic evaluation among patients with abnormal or worsening CPET variables.

Outpatient-based physical rehabilitation for survivors of prolonged critical illness: A randomized controlled trial.

INTRODUCTION: The physical and psychological impact of critical illness is well documented. Recovery may take many months and is often incomplete. The optimal way of addressing these important sequelae following hospital discharge remains unclear. METHODS: Single center, randomized controlled trial in patients invasively ventilated for ≥5 days. The treatment group (TG) underwent a 7-week, outpatient-based exercise and education program, with the control group (CG) receiving no intervention during the study period. Primary outcome measures were changes in functional capacity assessed using the cardiopulmonary exercise testing parameters, peak VO2, and anaerobic threshold (AT). Secondary outcome measures were changes in and health-related quality of life assessed using the Short Form 36 version 2 questionnaire. Assessors remained blinded to group allocation. RESULTS: Sixty-three patients completed the study (target n = 90). Improvements in both peak VO2 and AT were seen in both TG and CG but no significant difference between groups was evident. AT improved by 11.7% in CG (baseline 10.3 ml O2 kg(-1) min(-1), follow-up 11.5 ml O2 kg(-1) min(-1)), and by 14.6% in TG (baseline 10.3 ml O2 kg(-1) min(-1), follow-up 11.8 ml O2 kg(-1) min(-1); ANCOVA p = 0.74). Peak VO2 improved by 14.0% in CG (baseline 13.6 ml O2 kg(-1) min(-1), follow-up 15.5 ml O2 kg(-1) min(-1)), and by 18.8% in TG (baseline 13.8 ml O2 kg(-1) min(-1), follow-up 16.4 ml O2 kg(-1) min(-1); ANCOVA p = 0.68). Significant improvements were seen in both groups for physical component summary scores (PCS) (TG 39.6 versus 31.0; CG 36.1 versus 32.6) and mental component summary scores (MCS) (TG 48.6 versus 38.4; CG 41.3 versus 37.0). The degree of improvement was significantly higher in the treatment group in comparison to control subjects (PCS p = 0.048; MCS p = 0.017). This improvement was most marked in the subgroup ventilated for >14 days. CONCLUSIONS: A 7-week, outpatient-based exercise and education program resulted in improved health-related quality of life scores but not improved exercise capacity.

Myocardial infarction in intensive care units: A systematic review of diagnosis and treatment.

INTRODUCTION: Patients in the intensive care unit are vulnerable to myocardial injury from a variety of causes, both ischaemic and non-ischaemic. It is challenging for ICU clinicians to apply the conventional guidance concerning diagnosis and treatment. We conducted this review to examine the evidence concerning diagnosis and treatment of myocardial infarction in the ICU. METHODS: A systematic review was performed to identify relevant studies. RESULTS: 19 studies concerning use of ECG, cardiac enzymes, echocardiography and angiography were identified. 4 studies considered treatment of myocardial infarction. CONCLUSIONS: Regular 12 lead ECG or 12 lead ECG monitoring is more sensitive than 2 lead monitoring, regular measurement of cardiac enzymes is more sensitive than when provoked by symptoms. Coronary angiography rarely identifies treatable lesions, without regional wall motion abnormality on echocardiography. Evidence relating to treatment was limited. A potential strategy to diagnose myocardial infarctions in the ICU is proposed.

Exercise testing in survivors of intensive care--is there a role for cardiopulmonary exercise testing?

PURPOSE: The aims of this study were to assess the feasibility of cardiopulmonary exercise testing (CPET) for the early assessment of cardiorespiratory fitness in general adult intensive care unit (ICU) survivors and to characterize the pathophysiology of exercise limitation in this population. METHODS: Fifty general ICU survivors (ventilated for ≥ 5 days) performed a maximal cycle ergometer CPET within 6 weeks of hospital discharge. Health-related quality of life was measured by the Medical Outcome Study Short Form 36 version 2.0 questionnaire. RESULTS: Fifty patients (median age, 57 years; median Acute Physiology And Chronic Health Evaluation II score, 16) completed a CPET 24 ± 14 days after hospital discharge with no adverse events. Significant exercise limitation was present with peak Vo(2) 56% ± 16% predicted and anaerobic threshold (AT) 41% ± 13% of peak predicted Vo(2). Prospectively stratified subgroup comparison showed that patients ventilated for 14 days or more had a significantly lower AT and peak Vo(2) than those ventilated for 5 to 14 days (AT: 9.6 vs 11.7 mL/kg per minute O(2), P = .009; peak Vo(2): 12.9 vs 15.3 mL/kg per minute O(2), P = .022). At peak exercise, heart rate reserve was 25% ± 14%, breathing reserve was 47% ± 19%, and the respiratory exchange ratio was 0.96 ± 0.11. Ventilatory equivalents for CO(2) (Eqco(2)) were 39 ± 9. CONCLUSIONS: Significant exercise limitation is evident in patients who have had critical illness. Etiology of exercise limitation appears multifactorial, with general deconditioning and muscle weakness as major contributory factors. Early CPET appears a practical method of assessing exercise capacity in ICU survivors. Cardiopulmonary exercise testing could be used to select patients who may benefit most from a targeted physical rehabilitation program, aid in exercise prescription, and help assess the response to intervention.