| Effect of breathing rate on oxygen saturation and exercise performance in chronic heart failure. | |
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MedLine Citation:
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PMID: 9643792 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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BACKGROUND: In chronic heart failure (CHF), impaired pulmonary function can independently contribute to oxygen desaturation and reduced physical activity. We investigated the effect of breathing rate on oxygen saturation and other respiratory indices. METHODS: Arterial oxygen saturation (SaO2) and respiratory indices were recorded during spontaneous breathing (baseline) and during controlled breathing at 15, six, and three breaths per min in 50 patients with CHF and in 11 healthy volunteers (controls). 15 patients with CHF were randomly allocated 1 month of respiratory training to decrease their respiratory rate to six breaths per min. Respiratory indices were recorded before training, at the end of training, and 1 month after training. FINDINGS: During spontaneous breathing, mean SaO2 was lower in CHF patients than in controls (91-4% [SD 0.4] vs 95.4% [0.2], p<0.001). Controlled breathing increased SaO2 at all breathing rates in patients with CHF. Compared with baseline, minute ventilation increased at 15 breaths per min (+45.9% [9.8], p<0.01), did not change at six breaths per min, and decreased at three breaths per min (-40.3% [4.8], p<0.001). In the nine CHF patients who had 1 month of respiratory training, resting SaO2 increased from 92.5% (0.3) at baseline to 93.2% (0.4) (p<0.05), their breathing rate per min decreased from 13.4 (1.5) to 7.6 (1.9) (p<0.001), peak oxygen consumption increased from 1157 (83) to 1368 (110) L/min (p<0.05), exercise time increased from 583 (29) to 615 (23) min/s (p<0.05), and perception of dyspnoea reduced from a score of 19.0 (0.4) to 17.3 (0.9) on the Borg scale (p<0.05). There were no changes in the respiratory indices in the patients who did not have respiratory training. INTERPRETATION: Slowing respiratory rate reduces dyspnoea and improves both resting pulmonary gas exchange and exercise performance in patients with CHF. |
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Authors:
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L Bernardi; G Spadacini; J Bellwon; R Hajric; H Roskamm; A W Frey |
Publication Detail:
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Type: Clinical Trial; Controlled Clinical Trial; Journal Article; Randomized Controlled Trial |
Journal Detail:
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Title: Lancet Volume: 351 ISSN: 0140-6736 ISO Abbreviation: Lancet Publication Date: 1998 May |
Date Detail:
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Created Date: 1998-07-09 Completed Date: 1998-07-09 Revised Date: 2007-11-15 |
Medline Journal Info:
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Nlm Unique ID: 2985213R Medline TA: Lancet Country: ENGLAND |
Other Details:
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Languages: eng Pagination: 1308-11 Citation Subset: AIM; IM |
Affiliation:
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Department of Internal Medicine, IRCCS S Matteo, University of Pavia, Italy. LBern1ps@ipv36.unipv.it |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Dyspnea
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physiopathology Exercise Test Female Heart Failure / blood, physiopathology*, therapy Humans Male Middle Aged Oxygen / blood* Pulmonary Gas Exchange Respiration* Respiratory Therapy Ventilation-Perfusion Ratio |
| Chemical | |
Reg. No./Substance:
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7782-44-7/Oxygen |
| Comments/Corrections | |
Comment In:
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Lancet. 1998 May 2;351(9112):1299-300
[PMID:
9643788
]
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From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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