Proposed Topic (Most preferred): :
Clinical Safety and Quality Service III (Projects aiming at quality service to patients and their carers)
Proposed Topic (Second preferred): :
HA Young Investigators Session (Projects to be presented by HA staff who had joined HA for 10 years or less)
Authors (including presenting author) :
Kong ISY(1), Tsui AYY(1), Kwan CHY(2), Yim CW(2), Cheng RYF(2), Tseng DCK(2), Ng PK(2), Yip IKC(2), Lam KHM(1), Chan BSC(1), Siu SKY(1), Leung KKL(1)
Affiliation :
(1)Physiotherapy Department, Kowloon Hospital, (2)Department of Respiratory Medicine, Kowloon Hospital
Introduction :
Inspiratory muscle training(IMT) has been shown to improve inspiratory muscle strength, functional exercise capacity, dyspnea, and quality of life in patients with chronic obstructive pulmonary disease(COPD). It is important to emphasize the training for COPD patients with hypercapnia, a subgroup of patients characterized by persistent elevated arterial partial pressure of carbon dioxide(PaCO2), who are at heightened risk of respiratory failure, higher readmission rates, and elevated mortality. Studies have suggested that COPD patients with hypercapnia had a significant reduction in maximal inspiratory pressure(PImax) and there was a significant correlation between PImax and PaCO2. IMT could be a valuable treatment option for COPD patients with hypercapnia, with the potential to optimize the PaCO2 and thus alleviate the associated burden.
Objectives :
To investigate the effect of IMT training on patients with hypercapnic COPD.
Methodology :
Patients with a diagnosis of COPD who was referred for exercises testing from KH RMD SOPD and resulted with transcutaneous partial pressure of carbon dioxide(TcPCO2) greater than 6kPa at rest and during 6-minute walk test(6MWT) were recruited into an IMT program since 3 July 2023. The patients were provided with an inspiratory muscle trainer for home exercise. The exercise protocol involved 30 minutes of daily training, 5 days per week, for 8 weeks, with a resistance set at 40% of the patient's PImax. Outcome measures included PImax for inspiratory muscle strength, TcPCO2 for ventilatory efficacy, 6MWT and incremental cycle exercise test(ICET) for functional capacity, and St. George Respiratory questionnaire(SGRQ) for quality of life.
Result & Outcome :
Four male patients, aged 75-87 years old, with resting TcPCO2 levels of 6.3±0.36kPa, completed the training program. The results showed significant increase in PImax from 46±21.71 to 51.9±15.74cmH2O, indicating improved inspiratory muscle strength, with lower TcPCO2 level from 6.30±0.36 to 6.12±0.46kPa at rest and in decreasing trend during exercise testing. For functional capacity, significant improvements were found in 6-minute walk distance(6MWD), from 253±29.48 to 291±36.1meters(p=0.025), and work capacity from 0.67±0.77 to 2.01±1.40METs in ICET. Besides, patients experienced enhance quality of life as reflected by a reduction in the total score on SGRQ from 50.40±14.88 to 42.88±23.70. Importantly, the improvements in 6MWD, ICET, and SGRQ scores surpassed the threshold for minimal clinically important difference. The promising results, although from a small-scale program, indicate the importance of CO2 monitoring during exercise testing to identify COPD patients with hypercapnia and highlight the significance of IMT in the management of these patients.
