Effects of reducing inspired oxygen concentration for one hour in patients with chronic heart failure: implications for air travel. (May 2013)

• Record Type: Journal Article
• Authors: Hobkirk, James P.; Damy, Thibaud; Walters, Mandy; Bennett, Anna; Smith, Sarah J.; Ingle, Lee; Clark, Andrew L.; Cleland, John G.F.
• Is Part Of: European journal of heart failure. Volume 15:Number 5(2013)
• Page Start: 505
• Page End: 510
• Publication Date: 2013-05
• Subjects: Heart failure -- Periodicals; Heart Failure -- Periodicals; Insuffisance cardiaque -- Périodiques; Heart failure; Periodicals; 616.129005
• DOI: 10.1093/eurjhf/hft003
• Languages: English
• ISSNs: 1388-9842

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <sec id="ejhfhft003-sec-0001" sec-type="section"> <title>Aims</title> <p>The objective of this study was to establish the acute effects of hypoxia on clinical, spirometric, haemodynamic, and echocardiographic variables. Reducing inspired oxygen to 15%, as experienced during commercial air travel, decreases arterial oxygen saturation, increases respiratory rate and pulmonary artery pressure in healthy subjects. The effect on patients with chronic heart failure is unknown.</p> </sec> <sec id="ejhfhft003-sec-0002" sec-type="section"> <title>Methods and results</title> <p>Seventy‐two patients with chronic heart failure and an LVEF <40%, in NYHA functional class II (74%) or III (26%), on stable treatment were studied and compared with 18 age‐matched controls (65 ± 11 vs. 62 ± 12 years, respectively). Clinical, spirometric, haemodynamic, and echocardiographic measurements were performed in patients and controls before and after one hour inspiring 15% oxygen. Inspired 15% oxygen for 1 h was tolerated in all subjects and caused no worsening of symptoms. Arterial oxygen saturation decreased to a similar extent in patients (from 97 ± 2% to 86 ± 4%) and controls (from 97 ± 2% to 86 ± 3%). Mean arterial pressure increased from 81 ± 13 mmHg to 87 ± 12 mmHg in patients, but did not change in controls. There was no effect on heart rate, but systolic pulmonary artery pressure rose from 30.2 ± 14.0mmHg to 34.0 ± 15.2 mmHg in patients, and from 22.4 ± 5.5 mmHg to 24.1 ± 6.9 mmHg in controls.</p> </sec> <sec id="ejhfhft003-sec-0003" sec-type="section"> <title>Conclusions</title> <p>Inspiring 15% oxygen was tolerated and caused no worsening of symptoms despite reductions in arterial oxygen saturation and increases in mean arterial pressure and systolic pulmonary artery pressure.</p> </sec> </abstract>