Authors (including presenting author) :
WONG MSA(1), CHAN CMA(1), LEUNG KPA(1)
Affiliation :
(1)Physiotherapy Department, Queen Elizabeth Hospital
Introduction :
Paediatric intensive care unit (PICU) admissions are usually due to medical illness, accidents or life-threatening surgical conditions, leading to a high percentage being mechanically-ventilated. Physiotherapists play an important role in the multi-disciplinary team in removal of excessive secretion and weaning mechanical ventilation. Attributing to technology advancement, High Frequency Chest Wall Oscillation Therapy (HFCWOT), producing high-frequency, small-volume oscillations in the airways, was found to be effective in mobilization of retained airway secretion. Thus, it has been adopted as an adjunct to conventional chest physiotherapy in PICU at the Queen Elizabeth Hospital (QEH) since 2019.
Objectives :
To evaluate the effectiveness of combination of HFCWOT and conventional chest physiotherapy in mechanically ventilated patients in PICU.
Methodology :
Eight paediatric patients, aged 5.6±4.1 years old with acute pulmonary conditions and required mechanical ventilation in PICU at QEH in Jan 2019 to Dec 2020 were studied. All of them received daily conventional chest physiotherapy and addition of HFCWOT at a frequency of 10-15Hz for 20 minutes via “VEST” machine. Outcome measures included arterial blood gas and lung collapse index (scoring 0 to 3; 0=normal expansion, 1=single lobe collapse, 2=2-lobe collapse, 3=multiple lobe collapse). Evaluations were done at baseline (T1) and at the date of weaning off mechanical ventilator (T2). The number of days requiring mechanical ventilation and PICU stay were also evaluated.
Result & Outcome :
Arterial blood gas test results showed marked improvements in partial pressures of Oxygen and Carbon Dioxide. The lung collapse index was also significantly reduced upon completion on the entire course of combination of HFCWOT and conventional chest physiotherapy. The average number of days requiring mechanical ventilation and PICU stay for subjects with non-complicated past medical history were 9.78 and 12.22 days respectively while that of subjects with complicated past medical history was 42 and 125.5 days respectively.
Our preliminary findings demonstrated that combination of HFCWOT and conventional chest physiotherapy facilitated secretion mobilization in mechanically-ventilated patients in PICU, thus improved arterial blood gas profile and might assist in weaning off of mechanical ventilator. The rapid inflation and deflation provided by the HFCWOT creates pressure on the chest similar to clapping, helping mobilize sputum as well as transferring it to larger airways. Further studies involving more subjects are needed to determine an optimal HFCWOT parameters and treatment time to suit PICU needs.
