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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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Related in: MedlinePlus

Correlações das variações do VEF1% com a SpO2 mínima (em A), com ΔSpO2(em B) e com o tempo para atingir SpO2 mínima (Tmin; em C)
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f06: Correlações das variações do VEF1% com a SpO2 mínima (em A), com ΔSpO2(em B) e com o tempo para atingir SpO2 mínima (Tmin; em C)

Mentions: Em relação às correlações (Figura 3), oVEF1% apresentou uma correlação moderada positiva com a SpO2mínima (r = 0,356; p < 0,005), uma correlação moderada negativa com aΔSpO2 (r = −0,398; p < 0,001) e uma correlação moderada negativa como tempo para atingir a SpO2 mínima (r = −0,449; p < 0,001).


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)

Correlações das variações do VEF1% com a SpO2 mínima (em A), com ΔSpO2(em B) e com o tempo para atingir SpO2 mínima (Tmin; em C)
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f06: Correlações das variações do VEF1% com a SpO2 mínima (em A), com ΔSpO2(em B) e com o tempo para atingir SpO2 mínima (Tmin; em C)
Mentions: Em relação às correlações (Figura 3), oVEF1% apresentou uma correlação moderada positiva com a SpO2mínima (r = 0,356; p < 0,005), uma correlação moderada negativa com aΔSpO2 (r = −0,398; p < 0,001) e uma correlação moderada negativa como tempo para atingir a SpO2 mínima (r = −0,449; p < 0,001).

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