Physiological Response to Moderate Exercise Workloads in a Pulmonary Rehabilitation Program in Patients With Airflow Obstruction: Outcome Measurements

Pulmonary Function Tests: Pulmonary function evaluation was carried out 10 min after actuation from a metered-dose inhaler of two inhalations of both ipratropium bromide, 40 μg, and salbu-tamol, 200 μg. With the patients in a sitting position, spirometry was performed using an autolink spirometer (Transfer Test SN 293; P.K. Morgan; Haverhill, MA). The patients were required to perform three satisfactory spirometric techniques within 5% of each other by FVC; from the best of these maneuvers, FEV₁ and FVC were determined. The transfer factor for carbon monoxide was determined via the single breath method; in contrast to the spirometric data, the results of three maneuvers were averaged. Pulmonary function data of the 60 patients in the training group at the outset and termination of the study are detailed in Table 2. Additionally, comparable data from the 15 patients in the nontraining control group are shown in Table 2. in detail

Cycle Ergometer Test: Exercise testing was performed on an electromagnetically braked cycle ergometer (ER 900; Jaeger; Hoechberg, Germany) and was always preceded by a familiarization test on a different occasion. The patients breathed through a mouthpiece with a nose clip in place. Oxygen uptake (Vo₂), carbon dioxide output (Vco₂), minute ventilation (Ve), and the ventilatory equivalent for oxygen (Ve/Vo₂) were determined at intervals of 15 s by a respiratory mass spectrometer featuring a mixing chamber (Airspec QP9000; Case; Kent, UK). Gas exchange and respired minute volume were measured using the concentration of injected argon at a rate of 600 mL/min into the expirate upstream of the mixing chamber, while the resulting composition downstream was used to deduce the mass flows of all its components. The anaerobic threshold (AT) was determined from a plot of Vco₂ vs Vo₂ by the modified gas exchange V-slope technique described by Sue and coworkers. The identification of the AT was made blindly and independently by two observers from duplicate copies of the data. We recently reported a significant agreement between the V-slope technique and another noninvasive gas exchange method (plots of Ve and Ve/Vo₂ vs Vo₂) for the determination of the AT in COPD patients with a high interobserver agreement. Heart rate (HR) was recorded every minute by a monitor (PE 4000 Sports Tester Transmitter; Polar; Kempele, Finland) and arterial oxygen saturation (Sao₂) was measured using a pulse oximeter (Biox 3760; Datex-Ohmeda; Louisville, CO).

Table 2—Data on Postbronchodilator Pulmonary Function and Peak Exercise Responses Before and After the 12-Week Study in the Training (n = 60) and Nontraining Control (n = 15) Groups

	Training Group (n = 60)			Nontraining Control Group (n = 15)
Variables	Before	After	% Changef	Before	After	% Changef
Age, yr	64 ± 6			56 ± 12
Weight, kg	71.4 ± 17.2	71.4 ± 17.6		68.3 ± 17.7	70.7 ± 19.2
Height, cm	1.65 ± 0.09			1.64 ± 0.06
FEVj, L	1.45 ± 0.62	1.51 ± 0.68J	4	1.61 ± 0.71	1.54 ± 0.74	– 4
% predicted FEVj	55.1 ± 19.8	57.3 ± 17.1j	4	54.8 ± 18.4	52.4 ± 17.3	– 4
FVC, L	3.00 ± 0.80	3.19 ± 09	6	3.20 ± 1.02	3.03 ± 1.08	-5
FEV1/FVC, %	47.9 ± 14.2	46.7 ± 14.9	3	47.3 ± 11.6	48.3 ± 12.3	2
% predicted Tlco	67.02 ± 25.39	68.34 ± 26.03	2	69.82 ± 20.39	68.74 ± 27.33	-2
Peak WR, w	77 ± 30	91 ± 36|	18	71 ± 33	72 ± 33	1
Peak Vo2, L/min	1.14 ± 0.45	1.20 ± 0.52J	5	1.08 ± 0.47	1.08 ± 0.51	0
Peak Vco2, L/min	1.13 ± 0.49	1.23 ± 0.54J	9	1.04 ± 0.54	0.97 ± 0.49	-7
Peak Ve, L/min	42.4 ± 16.1	44.8 ± 19.1J	6	41.1 ± 17.4	41.6 ± 17.2	1
Peak HR, beats/min	135 ± 15	141 ± 17J	4	134 ± 24	130 ± 25	-3
Peak % Sao2	92 ± 2	90 ± 4	2	91 ± 2	91 ± 4	0

Category: Airflow Obstruction

Tags: COPD, exercise training, pulmonary rehabilitation