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Oxygen desaturation during the six-minute walk test in COPD patients.

Moreira MÂ, Medeiros GA, Boeno FP, Sanches PR, Silva Júnior DP, Müller AF - J Bras Pneumol (2014 May-Jun)

Bottom Line: The six-minute walk distance did not differ significantly between the groups.We found that FEV1% correlated significantly with the ΔSpO2 (r = -0.398; p < 0.001), Tmin (r = -0.449; p < 0.001), and minimum SpO2 (r = 0.356; p < 0.005).In the sevCOPD group, in comparison with the modCOPD group, SpO2 was lower and the Tmin was greater, suggesting a worse prognosis in the former.

View Article: PubMed Central - PubMed

Affiliation: Department of Pulmonology, Pulmonary Physiology Clinic, Porto Alegre, Brazil.

ABSTRACT

Objective: To evaluate the behavior of oxygen saturation curves throughout the six-minute walk test (6MWT) in patients with COPD.

Methods: We included 85 patients, all of whom underwent spirometry and were classified as having moderate COPD (modCOPD, n = 30) or severe COPD (sevCOPD, n = 55). All of the patients performed a 6MWT, in a 27-m corridor with continuous SpO2 and HR monitoring by telemetry. We studied the SpO2 curves in order to determine the time to a 4% decrease in SpO2, the time to the minimum SpO2 (Tmin), and the post-6MWT time to return to the initial SpO2, the last designated recovery time (RT). For each of those curves, we calculated the slope.

Results: The mean age in the modCOPD and sevCOPD groups was 66 ± 10 years and 62 ± 11 years, respectively. At baseline, SpO2 was > 94% in all of the patients; none received supplemental oxygen during the 6MWT; and none of the tests were interrupted. The six-minute walk distance did not differ significantly between the groups. The SpO2 values were lowest in the sevCOPD group. There was no difference between the groups regarding RT. In 71% and 63% of the sevCOPD and modCOPD group patients, respectively, a ≥ 4% decrease in SpO2 occurred within the first minute. We found that FEV1% correlated significantly with the ΔSpO2 (r = -0.398; p < 0.001), Tmin (r = -0.449; p < 0.001), and minimum SpO2 (r = 0.356; p < 0.005).

Conclusions: In the sevCOPD group, in comparison with the modCOPD group, SpO2 was lower and the Tmin was greater, suggesting a worse prognosis in the former.

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Monitoring of HR and SpO2.
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f01: Monitoring of HR and SpO2.

Mentions: The 6MWT was conducted in a 27-m corridor in accordance with the America ThoracicSociety guidelines.(7) At the HCPA, it is possible to monitor HR and SpO2 continuouslyby telemetry throughout the 6MWD with the use of a digital oximetry module and of asoftware program developed by the Biomedical Engineering team at HCPA. This systemallows the simultaneous transfer of HR and SpO2 data to the computer, makingit possible to monitor the degree of oxygen desaturation in real time, which therebyallows a better assessment of the degree of disease severity.(5,7)Figure 1 shows a recorded curve. All of theincluded patients completed the 6MWT without interruption and had a baselineSpO2 > 94%. None of the patients received supplemental oxygen duringthe test. We excluded from the sample those with orthopedic impairments, interstitialdiseases, or pulmonary arterial hypertension, or with any condition that wouldcompromise their ability to perform the 6MWT. The curves showing a ≥ 4% decrease inSpO2 were analyzed.


Oxygen desaturation during the six-minute walk test in COPD patients.

Moreira MÂ, Medeiros GA, Boeno FP, Sanches PR, Silva Júnior DP, Müller AF - J Bras Pneumol (2014 May-Jun)

Monitoring of HR and SpO2.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4109193&req=5

f01: Monitoring of HR and SpO2.
Mentions: The 6MWT was conducted in a 27-m corridor in accordance with the America ThoracicSociety guidelines.(7) At the HCPA, it is possible to monitor HR and SpO2 continuouslyby telemetry throughout the 6MWD with the use of a digital oximetry module and of asoftware program developed by the Biomedical Engineering team at HCPA. This systemallows the simultaneous transfer of HR and SpO2 data to the computer, makingit possible to monitor the degree of oxygen desaturation in real time, which therebyallows a better assessment of the degree of disease severity.(5,7)Figure 1 shows a recorded curve. All of theincluded patients completed the 6MWT without interruption and had a baselineSpO2 > 94%. None of the patients received supplemental oxygen duringthe test. We excluded from the sample those with orthopedic impairments, interstitialdiseases, or pulmonary arterial hypertension, or with any condition that wouldcompromise their ability to perform the 6MWT. The curves showing a ≥ 4% decrease inSpO2 were analyzed.

Bottom Line: The six-minute walk distance did not differ significantly between the groups.We found that FEV1% correlated significantly with the ΔSpO2 (r = -0.398; p < 0.001), Tmin (r = -0.449; p < 0.001), and minimum SpO2 (r = 0.356; p < 0.005).In the sevCOPD group, in comparison with the modCOPD group, SpO2 was lower and the Tmin was greater, suggesting a worse prognosis in the former.

View Article: PubMed Central - PubMed

Affiliation: Department of Pulmonology, Pulmonary Physiology Clinic, Porto Alegre, Brazil.

ABSTRACT

Objective: To evaluate the behavior of oxygen saturation curves throughout the six-minute walk test (6MWT) in patients with COPD.

Methods: We included 85 patients, all of whom underwent spirometry and were classified as having moderate COPD (modCOPD, n = 30) or severe COPD (sevCOPD, n = 55). All of the patients performed a 6MWT, in a 27-m corridor with continuous SpO2 and HR monitoring by telemetry. We studied the SpO2 curves in order to determine the time to a 4% decrease in SpO2, the time to the minimum SpO2 (Tmin), and the post-6MWT time to return to the initial SpO2, the last designated recovery time (RT). For each of those curves, we calculated the slope.

Results: The mean age in the modCOPD and sevCOPD groups was 66 ± 10 years and 62 ± 11 years, respectively. At baseline, SpO2 was > 94% in all of the patients; none received supplemental oxygen during the 6MWT; and none of the tests were interrupted. The six-minute walk distance did not differ significantly between the groups. The SpO2 values were lowest in the sevCOPD group. There was no difference between the groups regarding RT. In 71% and 63% of the sevCOPD and modCOPD group patients, respectively, a ≥ 4% decrease in SpO2 occurred within the first minute. We found that FEV1% correlated significantly with the ΔSpO2 (r = -0.398; p < 0.001), Tmin (r = -0.449; p < 0.001), and minimum SpO2 (r = 0.356; p < 0.005).

Conclusions: In the sevCOPD group, in comparison with the modCOPD group, SpO2 was lower and the Tmin was greater, suggesting a worse prognosis in the former.

Show MeSH
Related in: MedlinePlus