Kate Hayes

Long-term quality of life in patients with acute respiratory distress syndrome requiring extracorporeal membrane oxygenation for refractory hypoxaemia

IntroductionThe purpose of the study was to assess the long term outcome and quality of life of patients with acute respiratory distress syndrome (ARDS) receiving extracorporeal membrane oxygenation (ECMO) for refractory hypoxemia.MethodsA retrospective observational study with prospective health related quality of life (HRQoL) assessment was conducted in ARDS patients who had ECMO as a rescue therapy for reversible refractory hypoxemia from January 2009 until April 2011 in a tertiary Australian centre. Survival and long-term quality of life assessment, using the Short-Form 36 (SF-36) and the EuroQol health related quality of life questionnaire (EQ5D) were assessed and compared to international data from other research groups.ResultsTwenty-one patients (mean age 36.3 years) with ARDS receiving ECMO for refractory hypoxemia were studied. Eighteen (86%) patients were retrieved from external intensive care units (ICUs) by a dedicated ECMO retrieval team. Eleven (55%) had H1N1 influenza A-associated pneumonitis. Eighteen (86%) patients survived to hospital discharge. Of the 18 survivors, ten (56%) were discharged to other hospitals and 8 (44%) were discharged directly home. Sequelae and health related quality of life were evaluated for 15 of the 18 (71%) long-term survivors (assessment at median 8 months). Mean SF-36 scores were significantly lower across all domains compared to age and sex matched Australian norms. Mean SF-36 scores were lower (minimum important difference at least 5 points) than previously described ARDS survivors in the domains of general health, mental health, vitality and social function. One patient had long-term disability as a result of ICU acquired weakness. Only 26% of survivors had returned to previous work levels at the time of follow-up.ConclusionsThis ARDS cohort had a high survival rate (86%) after use of ECMO support for reversible refractory hypoxemia. Long term survivors had similar physical health but decreased mental health, general health, vitality and social function compared to other ARDS survivors and an unexpectedly poor return to work.

Effects of exercise training on exercise capacity and quality of life in patients with a left ventricular assist device: A preliminary randomized controlled trial

BACKGROUND A paucity of studies has examined the effect of exercise training after left ventricular assist device (LVAD) implantation. Previous research has demonstrated that insertion of the LVAD alone improves exercise capacity and quality of life (QOL). This study investigated whether supervised exercise training results in a further improvement. METHODS This prospective, randomized controlled trial with concealed allocation, assessor blinding, and intention-to-treat analysis investigated the effect of exercise training on exercise capacity and QOL in 14 patients who underwent LVAD insertion as a bridge to heart transplantation. Exercise training consisted of 8 weeks of gym-based aerobic and strengthening exercises 3 times a week, with a progressive mobilization program, compared with the control group that completed mobilization alone. Exercise capacity was measured before and after the intervention using maximal cardiopulmonary exercise testing and 6-minute walk distance (6MWD). QOL was measured using the Short Form 36-item assessment. RESULTS No adverse events were reported. There was a trend toward greater improvement in peak oxygen consumption (Vo(2)), 6MWD, and QOL in the exercise group (n = 7) compared with the control group (n = 7); however, no significant between-group difference was detected for improvements in peak Vo(2) [mean difference (exercise--control)] of 2.96 ml/kg/min (95% confidence interval, -1.04 to 6.97), 6MWD at 54 meters (-51 to 159 meters), and QOL scores over time (p > 0.05). CONCLUSION Exercise training is feasible and safe in patients with a LVAD. Trends toward greater improvement in exercise capacity and QOL after exercise training warrant further investigation in a larger trial.

Exercise studies in patients with rotary blood pumps: cause, effects, and implications for starling-like control of changes in pump flow.

This multicenter study examines in detail the spontaneous increase in pump flow at fixed speed that occurs in exercise. Eight patients implanted with the VentrAssist rotary blood pump were subjected to maximal and submaximal cycle ergometry studies, the latter being completed with patients supine and monitored with right heart catheter and echocardiography. Maximal exercise studies conducted in each patient at three different pump speeds on separate days established initially the magnitude and consistency of increases in pump flow that correlated well with changes in heart rate. However, there was considerable variation, coefficients of variation for mean heart rate and pump flow being 47.9 and 49.3%, respectively. Secondly, these studies indicated that increasing pump flows caused significant improvements in maximal exercise capacity. An increase of 2.1 L/min (35%) in maximum blood flow caused 12 W (16%) further increase in achievable work, 1.26 (9.3%) mL/kg/min in maximal oxygen uptake, and 2.3 (23%) mL/kg/min in anaerobic threshold. Mean increases in lactate were 0.85 mm (24%), but mean B-type natiuretic peptide fell by 126 mm, (-78%). From submaximal supine exercise studies, multiple linear regression of pump flow on factors thought to underlie the spontaneous increase in pump flow indicated that it was associated with increases in heart rate (P = 0.039), pressure gradient across the left ventricle (P = 0.032), and right atrial pressure (P = 0.003). These changes have implications for the recently reported Starling-like controller for pump flow based on pump pulsatility values, which emulates the Starling curve relating pump output to left ventricular preload. Unmodified, the controller would not permit the full benefits of this effect to be afforded to patients implanted with rotary blood pumps. A modification to the pump control algorithm is proposed to eliminate this problem.

Physiotherapy for patients following coronary artery bypass graft (CABG) surgery: limited uptake of evidence into practice.

The efficacy of physiotherapy techniques used for patients following uncomplicated coronary artery bypass surgery (CABG) is well documented. Previous research showed that some of this evidence was not rapidly adopted into practice by cardiothoracic physiotherapists; however, there has been no recent evaluation of the uptake of evidence. Our aim was to identify current physiotherapy interventions in use for patients following uncomplicated CABG surgery. A survey was sent to senior cardiothoracic physiotherapists from all Australian and New Zealand hospitals that perform CABG surgery. Fifty-four surveys were returned (response rate 88%). The most common treatments used were mobilisation (94% of hospitals), range of motion exercises (79%), deep breathing and/or cough (77%), cardiovascular exercise (42%), and incentive spirometry (40%). Respondents with a bachelor or diploma in physiotherapy were more likely to implement deep breathing exercises or coughing than those who obtained a postgraduate degree (p = 0.045). Respondents perceived personal experience as the most influential factor on postoperative treatment choices. Physiotherapists treating patients following uncomplicated CABG surgery continue to use interventions such as deep breathing exercises that are not supported by best available evidence. Standardised guidelines may be required to better match clinical practice with current literature.

Acute skeletal muscle wasting and relation to physical function in patients requiring extracorporeal membrane oxygenation (ECMO)

Purpose: Muscle weakness is common in patients requiring extracorporeal membrane oxygenation (ECMO), but early identification is challenging. This study aimed to 1) quantify the change in quadriceps size and quality (echogenicity) from baseline to day 10 using ultrasound in patients requiring ECMO, 2) determine the relationship between ultrasound measures, muscle strength and highest mobility level. Materials and methods: Prospective cohort study involving ultrasound measurement of quadriceps at baseline, days 10 and 20. Muscle strength and highest mobility level were assessed at days 10 and 20 using the Medical Research Council sum‐score (MRC), hand‐held dynamometry (HHD) and the ICU mobility scale (IMS). Results: 25 patients (age 49 ± 14 years, 44% male) received ECMO. There was a significant reduction (−19%, p < .001) in rectus femoris cross‐sectional area by day 10. Echogenicity did not change over time. There was a negative correlation between echogenicity and MRC at day 10 (r = −0.66) and HHD at day 20 (r = −0.81). At day 20, there was a moderate correlation between total muscle thickness and IMS (rho = 0.59) and MRC (rho = 0.56). Conclusions: In patients requiring ECMO there was marked wasting of the quadriceps over the first 10 days. Ultrasound measures were related to muscle strength and highest mobility level.

Physical Function in Subjects Requiring Extracorporeal Membrane Oxygenation Before or After Lung Transplantation

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) is used as a rescue therapy before and after lung transplantation, but little is known about functional recovery or complications after ECMO in this cohort. This study aimed to describe early physical function and leg complications in subjects who received ECMO before or after lung transplantation, and to compare functional outcomes to a matched cohort of subjects who did not require ECMO. METHODS: A retrospective study was conducted over 2 years. Highest mobility level was assessed, in both the ECMO and non-ECMO groups, prior to ICU admission, at ICU discharge, and at hospital discharge, while 6-min walk distance was measured at hospital discharge and at 3 months. Strength was assessed at ICU discharge and at hospital discharge in the ECMO subjects only, and leg complications were recorded up until hospital discharge. RESULTS: 17 subjects (mean age 43 ± 13 y; 65% (11 of 17 subjects) female) required ECMO before or after lung transplant. Survival to hospital discharge was 82% (14 of 17 subjects). At ICU discharge, strength and mobility levels were poor, but both improved by hospital discharge (P < .001). Leg complications were reported in 50% of survivors (7 of 14 subjects). ECMO survivors spent longer in the ICU (P < .001) and hospital (P = .002) and had worse physical function (ie, lower mobility level at ICU discharge, mean difference −1, P = .02; 6-min walk distance at hospital discharge: mean difference −99 m, P = .004) than lung transplant recipients not requiring ECMO (n = 28). CONCLUSIONS: In subjects requiring ECMO before or after lung transplantation, 82% survived to hospital discharge, but leg complications were common and physical function was poor at ICU discharge. Physical function improved over time, however subjects who required ECMO had a longer period of hospitalization and worse physical function at ICU and hospital discharge than those who did not require ECMO.