Correspondence

Effect of Aircraft-Cabin Altitude on Passenger Discomfort

N Engl J Med 2007; 357:1445-1446October 4, 2007

Article

To the Editor:

Muhm et al. (July 5 issue)1 report that at a barometric pressure equivalent to an altitude of 8000 ft (2438 m) above sea level, participants in their study had a maximum decrease of only 4.4 percentage points in oxygen saturation, as measured by pulse oximetry. We are concerned about the accuracy in their setting.2 To simulate high-altitude exercise in aircraft-cabin personnel, we examined 75 subjects between the ages of 24 and 62 years under normobaric, hypoxic conditions in a closed cabin with an oxygen content of 14.8%, the equivalent of conditions at an altitude of 9186 ft (2800 m), and a barometric pressure ranging from 1008 to 1040 mm Hg.3 We then compared measures of oxygen saturation on pulse oximetry with arterial blood gas analysis. In striking contrast to a maximum reduction of 12.2% in the mean oxygen saturation (normoxia vs. hypoxia during 35 minutes of exercise), there was a drop of 31.7% in the partial pressure of arterial oxygen, which led to a mean level of 48 mm Hg (95% confidence interval, 47 to 48) (Figure 1Figure 1Comparison of Mean Oxygen Saturation and Blood Gas Analysis during Exercise under Hypoxic Conditions.). Since levels of less than 60 mm Hg may be harmful pulse oximetry may not provide information accurate enough for the assessment of oxygen homeostasis2; air carriers and physicians should be aware of potential health risks.

Gustav Schäcke, M.D.
Cristian Scutaru, M.Sc.
David A. Groneberg, M.D.
Charité–Universitäts Medizin Berlin, D-12207 Berlin, Germany
gustav.schaecke.berlin.arbmed@t-online.de

3 References

1. 1

   Muhm JM, Rock PB, McMullin DL, et al. Effect of aircraft-cabin altitude on passenger discomfort. N Engl J Med 2007;357:18-27
   Full Text | Web of Science | Medline

2. 2

   Planes C, Leroy M, Foray E, Raffestin B. Arterial blood gases during exercise: validity of transcutaneous measurements. Arch Phys Med Rehabil 2001;82:1686-1691
   CrossRef | Web of Science | Medline

3. 3

   Schäcke G. Basics for preventive occupational survey when working in oxygen depleted atmosphere. Presented at the 28th International Congress on Occupational Health, Milan, June 11–16, 2006.
   

Citing Articles (1)

Citing Articles

1. 1

   Thomas Möller, Henrik Brun, Per M. Fredriksen, Henrik Holmstrøm, Eirik Pettersen, Erik Thaulow. (2010) Moderate Altitude Increases Right Ventricular Pressure and Oxygen Desaturation in Adolescents with Surgically Closed Septal Defect. Congenital Heart Disease 5:6, 556-564
   CrossRef