Hyperoxia
Oxygen continues to be given on the basis of presumed need rather than of documented low oxygen saturation (Dodd et al., 2000). Hale et al’s (2009) audit found that out of 40 patients brought to the emergency department with cardiac chest pain, 32 had received oxygen. Although, no study has demonstrated benefits from high flow oxygen for patients with cardiac ischemia, some studies have actually found that high concentrations of oxygen may in fact reduce myocardial blood flow (Rady et al., 1993). McNulty et al.’s (2005) study provided direct evidence that routinely using high flow oxygen in stable patients with ischemic heart disease may potentially cause harm by reducing the coronary artery blood flow. Beasley et al. (2006) supports this by suggesting high flow oxygen results in hyperoxia which can potentially cause adverse cardiovascular effects such as decreased cardiac output, thus contributing to poorer outcomes for patients. This implies that care needs to be taken when giving oxygen in excess to relieve hypoxemia as it can cause reduced oxygen consumption: this may be due to misdistribution of blood flow and the body protecting the vital organs (Beasley et al., 2006).