Authors (including presenting author) :
Lit PKM(1), Lee KH(1), Chow PS(1), Mak FT(1), Chan YH(1), Fong ST(1), Lam MK(1) Lai YKA(2)
Affiliation :
1. Respiratory Division, Department of Medicine, Queen Elizabeth Hospital 2. Associate Professor, School of Nursing and Health Sciences, Hong Kong Metropolitan University
Keyword 2: :
upright sitting
Keyword 3: :
Forward-leaning
Keyword 4: :
Forward-leaning to upright leaning
Keyword 6: :
aerosol drug delivery
Introduction :
Effective drug delivery in Chronic Obstructive Pulmonary Disease (COPD) is highly dependent on correct inhaler technique, which remains suboptimal despite training. Patients often adopt positions like leaning forward to alleviate dyspnea. Preliminary evidence suggests posture can influence aerosol deposition, and a forward-leaning to sitting upright (FLUS) maneuver is practiced clinically but not formally studied. This investigation evaluated the effect of body position on both physiological lung ventilation and technical inhaler performance.
Objectives :
The study aimed: 1) To identify the optimal body position for pMDI use by comparing lung ventilation dynamics across Sitting Upright (US), Leaning Forward (FL), and FLUS postures using Electrical Impedance Tomography (EIT). 2) To determine which position yields the most accurate inhalation technique by objectively assessing critical steps with an Aerosol Inhalation Monitor (AIM) and a standardized HAHO inhaler assessment checklist.
Methodology :
A pre-pilot trial involved 14 male COPD patients (mean age 70, mean FEV1% 61.7). In a single visit, participants performed pMDI maneuvers with a placebo canister in the three positions in randomized order. Objective technical performance was measured via the AIM and visually scored using the HAHO checklist (full score: 14). Lung ventilation was continuously recorded via EIT. Patient-reported preferences on comfort and perceived efficacy were collected via questionnaire, with rest periods between tests.
Result & Outcome :
The FLUS posture demonstrated superior outcomes. HAHO checklist scores were highest for FLUS (mean 8.71), with only one patient failing, compared to US (mean 4.43, 7 failures) and FL (mean 4.36, 7 failures). AIM data supported better deep-lung deposition in FLUS. Physiologically, EIT showed FLUS produced a significantly greater mean normalized ventilation amplitude (2.53) versus US (1.0) and FL (1.19), indicating enhanced lung expansion. Subjectively, patients rated perceived efficacy highest for FLUS (78%) and reported better rib cage elevation. One obese participant noted discomfort in the FL position. In conclusion, the FLUS posture is associated with significantly better inhaler technique scores, enhanced lung ventilation dynamics, and higher patient preference, suggesting it may optimize pMDI drug delivery in COPD. These findings warrant validation in a larger cohort and across different inhaler types.
