The Effectiveness of a Short-term Rehabilitation Programme of Preoperative High Intensity Exercise and Inspiratory Muscle Training to Improve Postoperative Recovery in Cancer Patients Undergoing Surgical Lung Resection

Introduction: Patients with operable lung cancer may be elderly, frail and multimorbid, presenting with debilitating symptoms that can increase the risk of postoperative pulmonary complications and result in extended hospital length of stays. It was hypothesised that a 2-4 week preoperative rehabilitation programme consisting of high-intensity interval training (HIIT) and inspiratory muscle training (IMT) could improve preoperative pulmonary function to optimise postoperative recovery. The twice weekly face-to-face programme was supervised by a qualified physiotherapist or exercise physiologist within a community gym setting and the virtual programme consisted of recorded videos and live online exercise sessions for patients to access at home. The aim of this study was to investigate the efficacy of the two modes of preoperative rehabilitation programmes in improving patient outcomes in comparison with standard care (no rehabilitation) in patients awaiting surgical resection for lung cancer.

Methods: A case-control cohort design evaluated the effectiveness and feasibility of preoperative HIIT and IMT for lung cancer patients delivered through the expansion of an existing Cardiac Rehabilitation Service. The preoperative rehabilitation programme was delivered either face-to-face or virtually and was compared to standard care. A total sample of 444 patient records were evaluated; standard care (n=166), face-to-face rehabilitation (n=142) and virtual rehabilitation (n=136). Groups were matched on age, BMI, ASA classification and extent of surgical resection undertaken. Patient data from a 3-year period was accessed to review hospital length of stay, incidence of pulmonary complications and 12-month survival. Pre and post intervention pulmonary function tests and health-related quality of life were measured alongside patient uptake, programme completion, HIIT attainment and patient or clinician reported adverse events in both rehabilitation groups.

Results: PiMAX improved significantly pre and post virtual rehabilitation, mean increase 1.312 cmH20 (p=0.001, 95% CI 0.535-2.089cmH20) and pre and post faceto-face rehabilitation, mean increase 1.144cmH20 (p<0.001, 95% CI 0.5581.730cmH20). Face-to-face rehabilitation significantly increased preoperative FEV1, mean difference 0.064 litres (p<0.001, 95% CI 0.032-0.096 litres), percentage predicted FEV1 2.79% (p<0.001, 95% CI 1.599-3.978%) and preoperative FVC 0.083 litres (p<0.001, 95% CI 0.045-0.121 litres). Virtual rehabilitation achieved nonsignificant increases in these pulmonary function measures and significantly increased percentage predicted FVC 2.74% (p=0.021, 95% CI 0.331-3.858%). Postoperative complication severity was significantly lower with virtual rehabilitation in comparison to standard care (p=0.002) but was not statistically different to face-to-face rehabilitation. Virtual rehabilitation had a significantly lower proportion of positive radiological findings at 20.6% compared to face-toface rehabilitation 33.8% (p=0.013). Despite significant improvements in pulmonary function and some improvement in postoperative complications with rehabilitation, hospital length of stay (mean ±SD) for virtual rehabilitation (8.13 days ±6.45) or face-to-face rehabilitation (9.75 days ±9.61) was not significantly different to standard care (8.27 days ±5.47) (p=0.114). Mean length of high dependency care was also not statistically different between groups (p=0.561). Preoperative rehabilitation groups did not differ statistically from standard care for antimicrobial therapy prescription, high flow oxygen requirement, tracheostomy insertion or chest drain duration. All factors indicative of postoperative pulmonary complications were associated with significantly increased risk of mortality 12 months post-surgery; postoperative tracheostomy insertion HR 8.19 (p<0.001, 95% CI 4.25-15.77), high flow oxygen requirement HR 3.90 (p<0.001, 95% CI 2.17-7.00), positive radiological findings HR 2.62 (p<0.001, 95% CI 1.58-4.35), positive sputum culture HR 2.44 (p=0.002, 95% CI 1.41-4.25) and antimicrobial therapy prescription HR 2.33 (p=0.002, 95% CI 1.38-3.94). Virtual or face-to-face rehabilitation did not influence 12-month survival although a poorer baseline physical activity status was associated with a significantly increased risk of mortality at 12-months HR 1.92 (p=0.001, 95% CI 1.33-2.77). No serious adverse events occurred with intervention and programmes had 100% uptake and high completion rates; virtual rehabilitation 76.5% and face-to-face rehabilitation 73.2%. 43% of patients in either mode of delivery were unable to achieve 80% HRR HIIT targets in the programme. Waiting time to surgery (mean ±SD) was significantly longer in face-to-face rehabilitation (23.48 days ±11.39) in comparison to virtual rehabilitation (19.92 days ±12.12) (p=0.033, 95% CI 0.23-6.89) and standard care (18.45 days ±19.92) (p<0.001, 95% CI 2.07-7.98).

Conclusion: A 2-4 week combined HIIT and IMT programme as a preoperative rehabilitation strategy can improve pulmonary function for patients awaiting surgical lung resection but improvements may not influence hospital length of stay, incidence of postoperative pulmonary complications or 12-month survival. Virtual rehabilitation appears to be a superior mode of delivery to influence clinical severity of postoperative complications and provide timely intervention in comparison to face-to-face rehabilitation. Cardiac Rehabilitation programmes could be a viable referral pathway for lung cancer patients to access rehabilitation programmes in the future but further research is needed to establish the cost effectiveness of these interventions prior to implementation.