Authors (including presenting author) :
Tam OY (1), Tsui CO (2), Thung KH (2), Chan S (2), Li KW (1), Kwan WS (1), Mak MY (1)
Affiliation :
(1) Department of Physiotherapy, Tuen Mun Hospital, (2) Department of Surgery, Tuen Mun Hospital
Introduction :
Post-operative pulmonary complications (PPC) after lung resection surgery are a major cause to serious morbidity and increased length of hospital stay (LOS). Inspiratory muscle training (IMT) is a breathing exercise against a resistance which aims to strengthen the respiratory muscles. Meta-analysis showed that preoperative IMT training was beneficial to patients undergo lung resection surgery by decreasing PPC and hospital LOS.
Therefore, pre-operative IMT to patients undergo lung resection surgery was implemented in 2020 to investigate its effectiveness in enhancing post-operative outcomes.
Objectives :
1. To investigate the effect of IMT on inspiratory muscle strength in patients awaiting lung resection surgery.
2. To investigate the effect of IMT on the incident of PPCs and hospital LOS for patients undergo lung resection surgery.
Methodology :
In this non-randomized study, patients underwent lung resection surgery in May to November 2019 served as the control group. They had no IMT and attended one educational session on post-operative care.
The intervention group included the patients planned for lung resection surgery in May to December 2020. Preoperative and individualized IMT was prescribed. They were trained to breathe with an inspiratory threshold loading device (Threshold IMT®). Maximal inspiratory pressure (MIP) was measured at baseline and the end of training period. The inspiratory load of the IMT started at 30% of their MIP. They were taught to exercise 15 minutes of IMT daily for at least one week before the surgery.
The primary outcome of this study is the incident of PPCs. The incident of PPCs was defined as written complications in discharge summary such as pneumonia, reintubation or post-operative ventilator dependence. The secondary outcome was hospital LOS. Paired-t test was used to determine the change of MIP of baseline while Mann-Whitney U statistic was used to determine the difference of LOS between two groups.
Result & Outcome :
21 patients (15males and 6 females), mean age of 65 received IMT with lung resection surgery done in May to December 2020, while there were 48 patients (26 male and 22 female) with mean age of 67 in the control group. Patients in intervention group exercised for a mean of 18.33 days without experiencing adverse events after IMT. The MIP was significantly improved (+14.33 cmH2O, p < 0.001). No PPCs were noted in intervention group where presented in 6 of 48 patients in the control group (12.5%). The mean hospital LOS was 5.71 days in the intervention group and 6.22 days in control group, which the difference was statically insignificance (p=0.422).
Conclusion
This pilot study showed that IMT was a safe intervention to improve the inspiratory muscle strength in patients awaiting lung resection surgery and may potentially have positive effect on reducing the incidence of PPCs in patients undergo lung resection surgery. Further study with larger sample size and more robust study design is needed to prove the effectiveness of IMT in enhancing post-operative outcome.
