Perioperative Bleeding: Omega-3 Rich Fish Oil Safe, Reduces Transfusion Needs

Fish oil supplements do not increase postoperative bleeding in patients undergoing cardiac surgery; in fact, they reduce the number of blood transfusions needed after the procedure. These new findings support the need to reconsider current recommendations that discourage the use of omega-3 supplements before cardiac surgery due to concerns about bleeding.

This discovery was made by researchers at the Sanford School of Medicine at the University of South Dakota (USA) and published last month in the journal Circulation. In reality, there is no significant scientific evidence linking uncontrolled bleeding to the use of omega-3 supplements. Some recent studies have even demonstrated the opposite; for example, a systematic review published in the Danish Medical Journal examined data from 16 studies on surgical patients and showed that fish oil supplements did not increase the risk of bleeding or blood loss (https://www.omegor.com/blog-omega-3/speciali-omega-3/omega-3-operazioni-chiururgiche/emorragia-chirurgica-integratori-olio-pesce-non-aumentano-rischio-sanguinamento/).

Furthermore, although EPA has been shown to have anticoagulant properties, there is no conclusive evidence of its role in the surgical setting. 

Omega-3 supplements do not cause bleeding in patients undergoing cardiac surgery 

In the new study, researchers performed a secondary analysis using data from a previous large-scale study called OPERA, which investigated the role of omega-3s in the incidence of postoperative atrial fibrillation. The number of bleeding events and units of blood transfused were secondary outcomes in this research. The results showed that fish oil supplementation had no effect on postoperative atrial fibrillation, but surprisingly, other data showed a significant reduction in the number of blood units needed for transfusions, and that higher levels of EPA and DHA in the blood on the morning of surgery correlated with a lower risk of bleeding for the operated patient. 

According to the researchers, these new findings support the need to reconsider current recommendations that advise stopping fish oil consumption before cardiac surgery, as stated by Professor Bill Harris, co-inventor of the Omega-3 Index. The Omega-3 Index expresses the percentage of EPA and DHA relative to total fatty acids in red blood cells and is a stable long-term indicator of omega-3 status that accurately reflects an individual’s EPA and DHA levels. An Omega-3 Index between 8% and 12% is considered the optimal range for reducing cardiac risk. 

Some details of the study 

The OPERA study included 1,516 patients, with an average age of 63, undergoing cardiac surgery involving coronary artery bypass grafting and valve surgery. Patients were randomly divided into two groups, receiving either omega-3 or a placebo. Specifically, the treatment group received high doses of EPA and DHA (from 6.5 to 8 grams total) two to five days before surgery, followed by 1.7 grams of omega-3 on the morning of surgery. This dosing was maintained until patient discharge. 

The primary outcome of the OPERA study was to determine if these acute doses of omega-3 reduced the risk of postoperative atrial fibrillation, a common and potentially dangerous complication of surgery. No effect was found. However, Harris’s team also examined bleeding criteria and the number of blood units required for transfusions in operated patients, discovering not only that higher EPA and DHA levels in the blood on the morning of surgery correlated with a lower risk of bleeding but also a significant reduction in the number of blood units used for transfusions in patients who took omega-3 compared to the placebo group. 

Bleeding measurements were made using a small razor blade to make incisions on the arm and assess coagulation time. As Harris himself stated, these tests do not correlate with the complexity of cardiac surgery, where incisions are large and the role of inflammation is not well understood, thus requiring further study. 

Fish oil is safe, and supplementation need not be stopped before surgery 

According to the researchers, the recent study demonstrates that fish oil supplements do not increase postoperative bleeding and reduce the number of blood transfusions. Furthermore, higher omega-3 levels were associated with a lower risk of bleeding. These new findings support the need to reconsider current recommendations advising stopping omega-3 supplementation prior to surgery, although their role in coagulation still requires further investigation.

Source: Emmanuel Akintoy, et al. “Fish Oil and Perioperative Bleeding. Insights From the OPERA Randomized Trial.” Circulation.