| Abstract [eng] |
Oxygen is essential for human survival, but its therapeutic use remains controversial in critical care settings. While oxygen supplementation is a cornerstone of critical care, its optimal dosage in specific clinical scenarios such as post-resuscitation therapy, sepsis management, cardiac surgery, and critically ill newborns remains unclear. Both hypoxia and hyperoxia can lead to detrimental patient outcomes by causing cellular damage and oxidative stress. The aim of this literature review is to evaluate the effect of oxygen therapy. The subsequent question is concerned with the variation in treatment requirements for these four different critical care settings. The aim is to develop practical treatment recommendations. Cardiac arrest causes sudden cessation of circulation, resulting in a lack of oxygen supply to the entire body. Restoration of the blood flow and oxygen supply is essential for the ischemic tissue. But a related increase in reactive oxygen species formation is concomitant with enhanced cellular damage and destruction. Studies recommend a controlled reoxygenation after return of spontaneous circulation with saturation targets of 94 to 98% to avoid consequences of hyperoxia. Sepsis describes a dysregulated host response to infection with hallmarks of hypotension, hypoxia, and life-threatening organ dysfunction. Oxygen therapy aims to address impaired microcirculation and increased metabolic demands. On the one hand, animal research showed that moderate hyperoxia can enhance immune response and reduce bacterial growth during sepsis. On the other hand, clinical trials with septic patients depict an increased risk of organ dysfunction and mortality in patients administered supranormal oxygen values above 97%. From recent clinical evidence, it can be concluded that saturation targets should be kept between 88 and 95%. In cardiac surgery, especially those requiring cardioplegia, adequate blood supply is a major challenge. In this case a cardiopulmonary bypass machine is used to either provide isolated pulmonary or cardiopulmonary support. The venovenous extracorporeal membrane oxygenation takes over the lung’s function of gas exchange while the venoarterial access additionally supports blood circulation. Oxygen therapy is used to improve tissue oxygenation and reduce ischemic injury associated with heart surgery. However, clinical trials could not verify any difference in organ function between patients receiving physiological oxygen saturation compared to hyperoxic supplementation. It can be inferred that it is safe to follow the conservative oxygen strategy since oxygen supplementation seems to play only a marginal role in the cause of postoperative organ failure. The focus of neonatology lies in the care of sick newborns and preterm infants, defined as a birth before the 37th week of gestation. The immature development leads to adjustment disorders as well as increased sensitivity to diseases and their treatment. Although oxygen titration to hyperoxic conditions enhances survival rates postnatally, it induces tissue and vascular damage to certain organs. Careful regulation of oxygen saturation is one measure that can be taken to reduce the risk of neonatal pathologies. |
