Safety and effectiveness of the high-frequency chest wall oscillation vs intrapulmonary percussive ventilation in patients with severe COPD

Figures & data

Figure 1 Flow chart detailing study methodology.

Abbreviations: GOLD, Global Initiative for Chronic Obstructive Lung Diseases; FEV₁, forced expiratory volume 1 second; HFCWO, high-frequency chest wall oscillation; IPV, intrapulmonary percussive ventilation.

Figure 2 (A) Intrapulmonary percussive ventilator. (B) High-frequency chest wall oscillator.

Table 1 Demographic, clinical, and functional parameters at baseline in the three groups

Variable	Control group (n=22)	IPV group (n=20)	HFCWO group (n=21)	p-value
Demographic and clinical characteristics
Age (years)	74.9±2.7	72.8±6.1	73.8±5.9	0.22
Male (%)	11 (50.0)	15 (75.0)	9 (42.8)	0.07
BMI (kg/m^2)	25.9±3.7	25.8±4.3	24.9±5.8	0.11
Exacerbations per year (n)	2.3±0.3	2.4±0.2	2.5±0.3	0.12
Hospitalizations per year (n)	1.1±0.3	1.3±0.4	1.2±0.3	0.14
Clinical and functional parameters
PaO2	69.8±10.4	71.8±7.8	72.0±10.0	0.18
PaCO2	41.7±6.0	42.5±4.8	41.8±2.7	0.21
pH	7.4±0	7.4±0	7.4±0	0.19
HCO3	24.6±1.5	23.3±2.0	24.8±1.9	0.20
FVC%	61.1 (16.3)	58.7 (13.4)	56.4 (13.2)	0.15
FEV1%	36.2±2.7	36.7±1.8	38.9±2.7	0.07
FEV1/FVC%	46.1±12.7	48.8±13.7	56.9±10.7	0.10
TLC%	140.6±22.2	117.3±31.7	132.5±34.7	0.11
RV%	192.4±67.0	183.0±66.8	149.6±39.3	0.09
DLCO%	52.9±5.6	60.6±15.0	65.8±12.1	0.06
MIP	5.7±2.0	6.2±2.0	6.6±3.1	0.09
MEP	6.5±2.7	7.4±1.9	7.1±1.9	0.08
6MWT (mt)	240±30	242±26	265±55	0.10
CRP	0.5±0.4	1.0±0.7	1.5±1.6	0.06
ϒGL	12.7±3.9	15.0±2.0	16.8±5.3	0.06
Scales
mMRC scale	3.2±0.9	2.7±0.9	2.5±1.1	0.07
CAT score	23.2±8.1	24.1±5.9	24.6±5.8	0.10
BCSS	4.9±1.4	6.3±1.4	6.4±2.6	0.06

Notes: Data are expressed as mean ± SD, unless otherwise stated. p-value <0.05; F-test for continuous variables and χ² for categorical variables.

Abbreviations: 6MWT, 6-minute walk test; ϒGL, gammaglobulin; BCSS, Breathlessness, Cough and Sputum Scale; BMI, body mass index; CAT, COPD Assessment Test; CRP, C-reactive protein; DLCO, diffusing lung capacity monoxide; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; HFCWO, high-frequency chest wall oscillation; IPV, intrapulmonary percussive ventilation; MEP, maximal expiratory pressure; MIP, maximal inspiratory pressure; mMRC, modified Medical Research Council; RV, residual volume; TLC, total lung capacity.

Table 2 Results of primary outcomes

	Before treatment			After treatment			Regression analysis p-value
	Control group	IPV group	HFCWO group	Control group	IPV group	HFCWO group	IPV vs control	HFCWO vs control	IPV vs HFCWO
Sex =0	10	15	9
Sex =1	10	5	11
Age (years)	74±3	72±7	74±6
BCSS	4.6±1.7	6.3±1.4	6.6±2.8	5.5±2.1	3.1±1.7	5.2±2.2	<0.001	0.007	0.001*
mMRC	3.1±0.8	2.7±0.9	2.5±1.0	3.2±0.8	2.4±0.9	2.4±0.9	0.01**	0.04**	0.6
CAT	23.7±7.4	24.7±5.9	24.9±6.4	26.9±7.6	17.0±6.3	20.9±6.9	<0.001	<0.001	0.02**

Note: Data are expressed as mean ± SD.

Abbreviations: BCSS, Breathlessness, Cough and Sputum Scale; CAT, COPD Assessment Test; HFCWO, high-frequency chest wall oscillation; IPV, intrapulmonary percussive ventilation; mMRC, modified Medical Research Council.

Figure 3 Median changes in BCSS and CAT before and after treatment in the three groups.

Abbreviations: BCSS, Breath, Cough and Sputum Scale; CAT, COPD Assessment Test; HFCWO, high-frequency chest wall oscillation; IPV, intrapulmonary percussive ventilation.

Table 3 Results of secondary outcomes (hematological, biochemical, and respiratory function parameters)

Variable	Before treatment			After treatment			Regression analysis p-value
	Control group	IPV group	HFCWO group	Control group	IPV group	HFCWO group	Control/IPV	Control/HFCWO	IPV/HFCWO
Leukocytes	8.033±1.749	7.938±1.886	7.433±2.028	9.335±1.558	7.519±1.907	7.155±1.755	<0.001	<0.001	0.7
Neutrophils%	65±9	70±11	66±9	71±9	66±8	63±8	<0.001	<0.001	0.4
Lymphocytes%	29±5	21±7	24±8	25±6	23±6	26±7	<0.001	<0.001	0.3
CRP	0.5±0.5	1.0±0.7	1.5±1.7	0.8±0.5	0.6±0.4	0.9±0.9	<0.001	<0.001	0.3
FVC	2.609±0.738	1.989±0.839	2.078±0.701	2.414±0.919	2.256±0.804	2.269±0.633	<0.001	<0.001	0.7
FVC%	65±10	60±16	66±12	59±12	68±13	71±9	<0.001	<0.001	0.7
FEV1	1.155±0.504	1.013±0.568	1.236±0.543	1.045±0.446	1.195±0.618	1.349±0.554	<0.001	<0.001	0.4
FEV1%	35±9	37±12	43±11	31±9	44.0±2.1	45.7±3.6	<0.001	<0.001	0.4
FEV1/FVC%	45.6%±13.4%	48.8%±13.0%	57.5%±11.9%	43.9%±12.2%	51.8%±11.0%	58.8%±13.4%	0.04	0.02	0.8
TLC	5.799±1.347	7.381±2.047	5.458±1.426	5.847±1.024	5.859±1.168	5.247±1.355	0.01	0.04	0.03
TLC%	139.±21	147.±31	133±35	145±18	137±23	124±28	0.01	0.04	0.04
RV	3.731±0.758	4.106±1.805	3.453±1.296	3.781±718	3.708±1.173	3.299±1.153	0.02	0.02	0.04
RV%	190±67	183±66	146±37	203±66	150±36	136±29	0.02	0.02	0.04
RV/TLC%	65.1%±9.7%	67.0%±13.5%	59.6%±9.7%	67.9%±13.0%	63.6%±8.1%	60.5%±9.7%	0.01	0.01	0.05
DLCO%	51.0%±5.7%	60.6%±15.0%	67.5%±12.3%	48.5%±14.1%	67.8%±9.1%	69.7%±5.7%	<0.001	<0.001	0.01
MIP (kPa)	5.8±2.1	6.2±2.0	6.8±2.3	5.3±1.8	8.1±2.0	7.5±2.8	<0.001	0.004	0.01
MEP (kPa)	6.4±2.4	7.4±1.9	7.2±2.1	5.8±2.0	9.3±1.4	8.0±2.4	<0.001	<0.001	0.01
pO2	69.1±10.1	71.8±7.8	71.8±10.4	67.9±9.5	76.3±6.3	74.8±9.6	<0.001	<0.001	0.2
pCO2	42.0±5.3	42.5±4.8	41.7±3.9	43.1±6.9	40.4±3.1	40.3±3.7	0.003	0.004	0.8
HCO3	24.3±1.2	23.6±2.0	24.4±1.8	24.0±1.3	23.4±1.8	23.9±2.1	0.07	0.08	0.10

Abbreviations: CRP, C-reactive protein; DLCO, diffusing lung capacity monoxide; FEV₁, forced expiratory volume in 1 second; FVC, forced vital capacity; HFCWO, high-frequency chest wall oscillation; IPV, intrapulmonary percussive ventilation; MEP, maximal expiratory pressure; MIP, maximal inspiratory pressure; RV, residual volume; TLC, total lung capacity.

Table 4 Changes in sputum cell count

Variable	Control group	IPV group	HFCWO group	Control group	IPV group	HFCWO group	p-value
							IPV/control	HFCWO/control	IPV/HFCWO
Total cells	4.52±1.51	4.83±135	4.45±1.54	5.26±1.25	4.12±75	3.98±1.08	0.001	0.001	0.15
Neutrophils	71±8	72±11	72±8	75±8	61±9	64±8	0.001	0.001	0.05
Lymphocytes	2.2±0.5	2.3±8	2.3±0.7	1.9±0.4	2.8±0.8	2.7±0.7	0.001	0.001	0.17
Eosinophils	2±1	3±2	2±1	2±1	3±1	3±1	0.07	0.06	0.19
Macrophages	16±7	15±12	16±10	21±6	4±5	16±5	0.01	0.01	0.11

Notes: Total cells count 10⁶/g. Neutrophils, lymphocytes, eosynophils, and macrophages are expressed as percentage ± SD.

Abbreviations: HFCWO, high-frequency chest wall oscillation; IPV, intrapulmonary percussive ventilation.

Table 5 Ratings and ranking of patient preferences for airway clearance techniques

Variable	IPV group	HFCWO group	p-value
Comfort	3.42±0.44	3.47±0.53	0.810
Efficacy	2.67±0.94	2.91±1.08	0.954
Ease of use	3.04±0.93	2.64±0.62	0.072
Convenience	3.21±0.33	2.91±0.16	0.754

Note: Values are expressed as mean ± SD.

Abbreviations: HFCWO, high-frequency chest wall oscillation; IPV, intrapulmonary percussive ventilation.