Valoración de la capacidad preoperatoria al ejercicio como factor predictivo de supervivencia en enfermos sometidos a trasplante pulmonar

Relationship of Exercise Capacity, Physical Function, and Frailty Measures With Clinical Outcomes and Healthcare Utilization in Lung Transplantation: A Scoping Review

Measures of exercise capacity, frailty, and physical function are commonly used in lung transplant candidates and recipients to evaluate their physical limitations and the effects of exercise training and to select candidates for transplantation. It is unclear how these measures are related to clinical outcomes and healthcare utilization before and after lung transplantation. The purpose of this scoping review was to describe how measures of exercise capacity, physical function, and frailty are related to pre- and posttransplant outcomes.

Methods

We considered studies of any design that included performance-based tests of exercise capacity, physical function, and frailty in adult lung transplant candidates or recipients. Outcomes of interest were clinical outcomes (eg, mortality, quality of life) and healthcare utilization.

Results

Seventy-two articles met the inclusion criteria. The 6-min walk test (6MWT) was shown to be related to mortality on the waiting list with different distance values as cutoffs points. There were inconsistent results regarding the relationship of the 6MWT with other clinical outcomes. Few studies have examined the relationship between the cardiopulmonary exercise test or the short physical performance battery and clinical outcomes, although some studies have shown relationship with survival posttransplant and quality of life. Few studies examined the relationship between the tests of interest and healthcare utilization' and the results were inconsistent.

Conclusions

Except for the relationship between the 6MWT and mortality on the waiting list, there is limited evidence regarding the relationship of performance-based measures of exercise capacity, frailty, and physical function with clinical outcomes or healthcare utilization.

Pre-operative stress testing in the evaluation of patients undergoing non-cardiac surgery: A systematic review and meta-analysis

Background

Pre-operative stress testing is widely used to evaluate patients for non-cardiac surgeries. However, its value in predicting peri-operative mortality is uncertain. The objective of this study is to assess the type and quality of available evidence in a comprehensive and statistically rigorous evaluation regarding the effectiveness of pre-operative stress testing in reducing 30-day post -operative mortality following non -cardiac surgery.

Methods

The databases of MEDLINE, EMBASE, and CENTRAL databases (from inception to January 27, 2016) were searched for all studies in English. We included studies with pre-operative stress testing prior to 10 different non-cardiac surgery among adults and excluded studies with sample size<15. The data on study characteristics, methodology and outcomes were extracted independently by two observers and checked by two other observers. The primary outcome was 30-day mortality. We performed random effects meta-analysis to estimate relative risk (RR) and 95% confidence intervals (95% CI) in two-group comparison and pooled the rates for stress test alone. Heterogeneity was assessed using I² and methodological quality of studies using Newcastle-Ottawa Quality Assessment Scale. The predefined protocol was registered in PROSPERO #CRD42016049212.

Results

From 1807 abstracts, 79 studies were eligible (297,534 patients): 40 had information on 30-day mortality, of which 6 studies compared stress test versus no stress test. The risk of 30-day mortality was not significant in the comparison of stress testing versus none (RR: 0.79, 95% CI = 0.35–1.80) along with weak evidence for heterogeneity. For the studies that evaluated stress testing without a comparison group, the pooled rates are 1.98% (95% CI = 1.25–2.85) with a high heterogeneity. There was evidence of potential publication bias and small study effects.

Conclusions

Despite substantial interest and research over the past 40 years to predict 30-day mortality risk among patients undergoing non-cardiac surgery, the current body of evidence is insufficient to derive a definitive conclusion as to whether stress testing leads to reduced peri-operative mortality.

Six-minute walk test before and after large-volume paracentesis in cirrhotic patients with refractory ascites: A pilot study

BACKGROUND/AIMS

Functional impairment is common among cirrhotic patients with refractory ascites, and improvement in functional impairment is an expected issue after paracentesis. The six-minute walk test (6MWT) is considered an objective test for functional activity. No published data have evaluated the 6MWT among cirrhotic patients with refractory ascites before and after large-volume paracentesis. The research aim was to assess the feasibility of performing the 6MWT among cirrhotic patients who had refractory ascites before and after large-volume paracentesis.

MATERIALS AND METHODS

Thirty-one cirrhotic inpatients with refractory ascites were subjected to pulmonary function tests (forced expiratory volume in one second [FEV1], forced vital capacity [FVC], FEV1/FVC) and diffusion lung capacity for carbon monoxide (DLCO) before and 48 h after therapeutic large-volume paracentesis. Dyspnoea as assessed by the Borg scale and functional capacity as assessed by the 6MWT were also evaluated.

RESULTS

Prior to paracentesis, the mean values of FVC and FEV1 were lower than the predicted values, and a significant increase was observed after paracentesis. There was improvement in the mean DLCO values after paracentesis (P < 0.05). Regarding the 6MWT, significant increases in the walked distance (6MWD) (310.7 ± 73 vs. 348.7 ± 72.3 m) and oxygen saturation after paracentesis (P = 0.001) were observed. Significant improvement in the dyspnoea scale also occurred after paracentesis (P = 0.001). A significant positive correlation between the 6MWD before paracentesis and serum albumin levels was demonstrated (r = 0.373, P = 0.039).

CONCLUSION

We found a decrease in pulmonary function and the 6MWD in patients who had refractory ascites, which improved significantly following large-volume paracentesis. The 6MWT is useful in detecting impaired functional capacity among cirrhotic patients.

Use of Six-Minute Walk Test to Measure Functional Capacity After Liver Transplantation

BACKGROUND

Functional impairment is common in people with chronic liver disease (CLD), and improvement is expected following liver transplantation (LT). The Six-Minute Walk Test (6MWT) is an objective measure of functional performance.

OBJECTIVE

The aims of this study were: (1) to evaluate the feasibility of 6MWT performance after LT, (2) to compare post-LT 6MWT performance over time between patients with and without CLD, (3) to determine when post-LT 6MWT performance approaches expected values, and (4) to investigate predictors of poor 6MWT performance.

METHODS

The 6MWT was performed by 162 consecutive ambulatory participants (50 healthy controls, 62 with CLD, 50 with LT). Sex, age, and body mass index were used to predict expected 6MWT performance. Chi-square testing, analysis of variance, and Pearson coefficients compared percentage of predicted 6-minute walk distance (%6MWD) across groups. Multivariable mixed models assessed predictors of improvement.

RESULTS

The participants' mean age was 53.5 years (SD=13.0), 39.5% were female, and 39.1% were nonwhite. At 1-month post-LT, only 52% of all LT recipients met the inclusion criteria for 6MWT performance. Mean %6MWD values for female participants improved from 49.8 (SD=22.2) at 1 month post-LT to 90.6 (SD=12.8) at 1 year post-LT (P<.0001), which did not differ statistically from the CLD group (X̅=95.9, SD=15.6) or the control group (X̅=95.6, SD=18.0) (P=.58). However, at 1-year post-LT, mean %6MWD values for male participants (X̅=80.4, SD=19.5) remained worse than for both the CLD group (X̅=93.3, SD=13.7) and the control group (X̅=91.9, SD=14.3) (P=.03). Six-Minute Walk Test performance was directly correlated with the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) physical component score (r=.51, P<.01) and was inversely correlated with nonalcoholic steatohepatitis (r=-.52, P<.01) and diabetes (r=-.48, P<.05). In multivariate analysis adjusted for age and sex, hepatitis C independently predicted 6MWT improvement (estimated β=69.8, standard error=27.6, P=.01).

LIMITATIONS

A significant proportion of patients evaluated for enrollment were excluded due to level of illness early after LT (n=99, 47.4%). Thus, sampling bias occurred in this study toward patients without significant postoperative complications.

CONCLUSIONS

The 6MWT is a simple test of physical functioning but may be difficult to apply in LT recipients. The 6MWT performance improved following LT but was lower than expected, suggesting a low level of fitness up to 1 year following LT.

Rehabilitation and 6-minute walk test after liver transplantation

BACKGROUND

Measurement of exercise capacity is an integral element to assess patients after surgery. Although the 6-minute walk test (6MWT) provides information regarding functional capacity, response to therapy, and prognosis across a range of conditions, its applicability for liver transplant recipients remains to be established. The aim of our study was to examine whether the 6MWT in combination with a subjective rating of perceived exertion (Borg Scale [BS]) could be used to evaluate exercise capacity among patients after liver transplantation (OLT).

METHODS

Thirteen consecutive subjects were enrolled in this single-center study during routine rehabilitation of the 6MWT and BS. At days 7 and 14 after OLT seeking to assess objective and subjective exercise capacities, we recorded basic clinical parameters, including body weight, blood pressure, heart rate and temperature. The results as compared between days 7 and 14 were related to the reference values for age-, height- and weight-matched healthy subjects.

RESULTS

On day 7, normal 6MWT was achieved by one patient and at day 14-, by three patients. At days 7 and 14, the average distances of 6MWT were 326.7 m and 421 m, respectively (P<.05), indicating a significant increase in exercise capacity. The average BS rating did not change significantly between days 7 and 14, indicating, that the increased exercise capacity was achieved without excessive effort.

CONCLUSIONS

Our study indicated that the 6MWT and BS may represent inexpensive and safe assessment methods for exercise capacity after OLT. This evaluation may be helpful to plan and optimize post-OLT rehabilitation.

Lung transplantation in autoimmune diseases

In the last 45 years, lung transplantation has evolved from its status as a rare extreme form of surgical therapy for the treatment of advanced lung diseases to an accepted therapeutic option for select patients. Although pulmonary fibrosis and pulmonary vascular diseases are important indications for lung transplantation, only a small percentage of transplants are performed in patients with collagen vascular diseases. The reasons for this low number are multifactorial. This article reviews issues relevant to all lung transplant candidates and recipients as well as those specific to patients with autoimmune diseases.