Coronary heart disease (CHD) remains a significant cause of death, accounting for 1 in 10 deaths worldwide.
International guidelines recommend improving or decreasing the cardiac workload using a combination of therapies known as MONA: morphine, oxygen, nitrates, and aspirin.
Oxygen, via face mask or nasal cannula, is often administered to patients with suspected AMI.
According to Dion Stub, MBBS, PhD, from The Alfred Hospital in Melbourne, Australia, treating AMI with oxygen has its roots in practices dating back more than a century. “Oxygen was first administered to patients with suspected ACS in 1900, and to this day is given to [more than] 90% of patients with cardiac emergencies. Whilst other medical practices from the early 1900s — such as starvation diets for aneurysms and mercury as a treatment for infections — were quickly discarded, the routine use of oxygen in cardiac emergencies has remained a pervasive component of first medical response,” Dr Stub told Cardiology Advisor.
Oxygen therapy may decrease cardiac blood flow and perfusion, reduce cardiac output, and increase coronary vascular resistance.
In 2010, Juan Cabello, MD, PhD, from Hospital General Universitario de Alicante in Spain, and colleagues published a review of the literature for oxygen therapy in AMI conducted to determine whether this practice is helpful or harmful. They found that robust evidence to support the use of oxygen to treat AMI was lacking.
The uncertainty of whether oxygen therapy in AMI is beneficial or harmful has stimulated the development of clinical trials examining this question.
According to Dr Cabello, no firm recommendation can be made regarding oxygen therapy for AMI given the low quality and scarcity of the available clinical trial evidence. “The message for clinicians is that we still do not know if oxygen is helpful, harmful, or useless,” he said. “There are theoretical reasons why it could help and also why it could do harm.”
“This updated Cochrane Review further emphasizes the message that oxygen should be treated like all other medical therapies, in which efficacy needs to be balanced with the side effect profile,” Dr Stub said.