B108-13 Associated Changes in Exercise Endurance, Physical Capacity and Aerobic Fitness Accrued via Pulmonary Rehabilitation in Patients Preparing for Lung Transplantation

Introduction

Poor physical conditioning and cardiorespiratory fitness are both confounding factors in patients with end-stage lung disease (ESLD). To improve overall fitness and conditioning prior to lung transplantation (LTX), patients with ESLD often participate in a Pulmonary Rehabilitation (PR) program, the goal of which is to enhance their ability to recover from the upcoming surgical procedure. However, the actual physiological benefits accrued via PR are uncertain.

Methods

While awaiting LTX, patients with ESLD were enrolled in a PR program. Before beginning the program, patients had recorded an ‘initial’ six-minute walk distance (6MWD)[a metric of endurance] and an ‘initial’ cardiopulmonary exercise test (CPET) [UltimaTM CardiO2® Gas Exchange Analysis System - MGC Diagnostics] where, utilizing a bicycle ergometer, patients were exercised to volitional exhaustion. Patients then completed a variable number of PR sessions following which both a ‘final’ 6MWD and CPET were performed. All CPETs were performed while administering 30% FiO2 oxygen. Peak oxygen consumption (VO2 peak) [a metric of aerobic fitness] and peak work load (Watts) [a metric of physical capacity] were measured during both CPETs.

Results

Thirty-three patients were evaluated and their demographics are detailed in Table 1. The average number of PR sessions between CPETs was 17+5.3 (range 10-36). Following conclusion of the PR sessions, there was a significant increase in 6MWD from 1017.6+269.9 to 1223.7+ 07.7 feet (p < 0.001). There was also a positive correlation between the final 6MWD and the attained VO2 peak (r2=0.48, p < 0.01) even though there was no incremental improvement in the VO2 peak between the initial and final CPETs (13.3+4.8 to 13.2+4.6ml/kg/min) [p = 0.81]. Additionally, following the PR sessions there was a significant improvement in the attained peak work load (45.6+26.9 to 51.1+28.4 Watts) [p = 0.01], with the final peak work load having a positive correlation with the final 6MWD (r2=0.48, p < 0.01). The number of completed PR sessions did not correlate with incremental changes in the VO2 peak (r2=0.28, p = 0.11), Watts (r2=0.10, p = 0.58) or 6MWD (r2=0.28, p = 0.12).

Conclusions

Patients with ESLD awaiting LTX and completing > 10 sessions of PR, demonstrated increased endurance and physical capacity, but not cardiorespiratory fitness. The attained 6MWD, while demonstrating endurance, appears also to reflect improvements in physical capacity. However, further research is warranted to determine the amount of pre-LTX PR necessary to improve aerobic fitness.

This abstract is funded by: Ohio Solid Organ Transptant Consortium