Authors (including presenting author) :
Lee BTS(1), Lam CKM(2), Tsui CO(3), Tam JOY(4), Cheng BCP(2), Lau CW(2), Mak MMY(4), Kwan AWS(4), Tung KLH(4), Wong A(4), Thung KH(3)
Affiliation :
(1) Department of Anaesthesia, Caritas Medical Centre, (2)Department of Anaesthesia and Operating Theatre Services, Tuen Mun Hospital, (3)Department of Surgery, Tuen Mun Hospital, (4)Department of Physiotherapy, Tuen Mun Hospital
Introduction :
Major surgery elicits neuroendocrine inflammatory response, imposing great challenges on patients’ physiology. One of the adverse effects is post-operative pulmonary complications (PPCs), which can result in significant morbidity and even mortality. To reduce the risks of such events, efforts have been made to identify at-risk to modify the risk factors. This gives rise to the concept of prehabilitation, which aims to enhance the “physiological reserve” of patients to mitigate the effects of surgical stress response in hopes of avoiding or overcoming complications. Pre-operative exercise therapy is a cornerstone of prehabilitation programme, while inspiratory muscle training (IMT) aims to specifically improve inspiratory muscle strength and endurance. This is based on the principle that respiratory muscles, like other skeletal muscles, would adapt to training load by undergoing structural and biochemical changes. Perioperative IMT is available in Tuen Mun Hospital as part of the multimodal prehabilitation programme. To date, there is no local data on perioperative IMT in the surgical patients. While waiting for results from ongoing randomised trials, we would like to perform clinical assessment on the feasibility and efficacy of our IMT program, and the potential benefits on patient outcome.
Objectives :
This pre vs post interventional study set out to evaluate the clinical efficacy of perioperative IMT and its feasibility in Hong Kong.
Methodology :
Preoperative IMT was provided from 1 September 2020 to 31 December 2021 to patients undergoing major lung resection in Tuen Mun Hospital. Training was carried out using a handheld breathing trainer in outpatient settings. Maximal inspiratory pressure (MIP) was measured before and after IMT. The primary outcome was >10% improvement in MIP.
Result & Outcome :
49 subjects were analyzed. There was significant improvement in MIP. Mean initial MIP of all patients increased from 61.84cmH2O (SD 19.17) to 72.8cmH2O (SD 20.55) after IMT, with 21% mean improvement (SD 0.24, 95%CI 0.0404 – 0.1762, P=0.002, β=0.11). A mean increase of 24% and 15% was also observed in female and male subgroups, which improved from mean initial MIP 57.3cmH2O vs 70.52cmH2O to 68.54cmH2O vs 80.38cmH2O. Patients with poor initial MIP benefited most from IMT. 13/24 (54.2%) [female vs male, 7/11 (63.6%) vs 6/13 (46.2%)] had MIP improved to average values or above and 21/24 (87.5%) [female vs male, 10/11(90.9%) vs 11/13 (84.6%)] had MIP increased more than 10% after IMT (p=0.015). Significantly more patients without preoperative IMT developed PCCs than patients undergoing IMT program [19/87(21.8%) vs 2/39 (5.1%), p=0.020]. Preoperative inspiratory muscle training is an effective way to improve patient’s respiratory function and prevent PPCs. Its application in local perioperative settings is feasible.
