What is a dangerous low oxygen level

An oversupply of oxygen should also be avoided

30.07.2018

Oxygen is vital, but too much of it can increase patient mortality. The pulmonologists of the Association of Pneumological Clinics (VPK) warn against this and strongly recommend checking the patient's current oxygen saturation level before administering oxygen.

It is well known that a lack of oxygen (hypoxemia) can lead to unconsciousness, cardiac arrest and various physical damage. The administration of oxygen can be life-saving in such cases, which is why many patients in the hospital are generously supplied with additional oxygen. However, too much oxygen can also increase patient mortality. The pulmonologists of the Association of Pneumological Clinics (VPK) warn of this, citing a current meta-study with over 16,000 patients who had to be treated in hospital for an acute illness (such as blood poisoning, cardiac arrest, serious injuries or emergency surgery) (see The Lancet, published online on April 28, 2018). 50 to 84 percent of those affected who were ventilated either through a nasal cannula or non-invasively through a breathing mask or invasively through a ventilation tube integrated into the windpipe received too high a concentration of oxygen. "The oxygen oversupply (hyperoxemia) increased your mortality risk in the hospital by 21 percent and 30 days after discharge from the clinic by 14 percent, without any significant improvement in other health aspects," reports Dr. med. Thomas Voshaar, Chairman of the Board of the Association of Pneumological Clinics (VPK) and Chief Physician of the Lung Center at Bethanien Hospital in Moers.

Only give oxygen if there is an actual lack of oxygen

Too much oxygen is toxic and can lead to inflammation, oxidative stress and narrowing of blood vessels in the lungs, cardiovascular and nervous systems. If oxygen is supplied in spite of sufficient oxygen saturation, the risk of lung failure, heart attacks, cardiac arrhythmias, cardiac arrhythmias increases
Disturbances of the heartbeat sequence as an expression of a disturbance or permanent damage in the area of ​​the cardiac conduction system.
and organ failure. “According to the authors of the study, an additional dose of oxygen can already have harmful effects if the oxygen saturation in the blood is 94 to 96 percent prior to administration. With increasing oxygen saturation in the blood, the risk of death for patients increases steadily. Nevertheless, some doctors consider the administration of oxygen to be a potentially helpful and harmless therapy - regardless of whether the patient actually has an oxygen deficiency or not, ”explains Dr. Voshaar.

It is essential to check the patient's oxygen saturation

One speaks of an oxygen deficiency when the oxygen saturation in the capillary blood is below 90 percent. In contrast, the range in which the optimal oxygen saturation should be has been defined inconsistently by various specialist societies. Further study is needed to find an optimal range of oxygen saturation that maximizes the benefits of supplemental oxygen and minimizes potential harm. "Since an excessive supply of oxygen can be life-threatening, we recommend pulmonologists from the VPK to check the patient's current oxygen saturation level before administering oxygen," emphasizes Dr. Voshaar. After all, arterial oxygen saturation can be measured very easily and non-invasively with a pulse oximeter - this is a light sensor that is attached to the patient's finger like a clip and then uses the light absorption when x-raying the skin to determine the oxygen saturation in the capillary blood. In lung patients, the carbon dioxide content and the pH value of the blood should also be determined in order to detect weak respiratory muscles or acute deterioration (so-called exacerbation) as early as possible.

Source: äin-red

This is a press release from the Association of Pneumological Clinics (VPK). This press release or parts of the article can be printed under the following source: www.lungenaerzte-im-netz.de. In the case of publication in online media, this source is required (in the form of an active link either to the home page or to a subpage of the pulmonary doctors-on-the-net website); if published in print media, reference to this web address is also required.


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Photo: Fachkrankenhaus Grafschaft monastery, Schmallenberg