Monitoring of Heart Performance Lacking in Most High-Risk Operations

Only 35% of anesthesiologists carry out cardiac output monitoring (COM), a simple procedure that could make a significant impact on patient recovery during high-risk surgery, according to a new study.

Researchers at the University of California, Irvine (UCI; USA) conducted a survey of 463 randomly selected European and US anesthesiologists. The researchers wanted to examine if the anesthesiologists measured the three main parameters used to measure oxygen delivery; hemoglobin levels, oxygen saturation, and cardiac output. The researchers found that while hemoglobin levels were usually checked regularly during high-risk surgery, and continuous measuring of oxygen saturation is compulsory during anesthesia in all European countries, 65% of them were failing to perform COM.

The main reasons given for not performing COM were that cardiac output monitors were too invasive; that anesthesiologists were using a surrogate for cardiac output monitoring, such as checking variations in pulse pressure; and 30% of respondents believed that cardiac monitoring did not provide important information. As a result of their findings, the researchers are calling for action at national and international level to ensure that COM is carried out for all high-risk surgical operations. The study was presented at the European Anesthesiology Congress, held during June 2011 in Amsterdam (The Netherlands).

"Several studies have shown that when anesthesiologists measure and then set goals for cardiac output during high-risk surgery, their patients will have fewer postoperative complications, a shorter stay in the hospital after the surgery, and fewer of them will die in the postoperative period," said lead author Maxime Cannesson, MD, an associate professor of anesthesiology at UCI. "Our study shows that there is a need for action by national and international professional societies to ensure that cardiac output monitoring is used in clinical practice for these patients."

Cardiac output is the volume of blood being pumped by the heart every minute, usually the combined sum of output from the right ventricle and the output from the left ventricle during the phase of systole of the heart. An average resting cardiac output would be 5.6 L/min for a human male and 4.9 L/min for a female.

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