Study: Too Many Blood Tests Can Cause Anemia in Heart Patients

Study: Too Many Blood Tests Can Cause Anemia in Heart PatientsA recent study published in the Archives of Internal Medicine found that one in five patients who receive hospital treatment after heart attacks become anemic because of the amount of blood drawn during routine diagnostic tests, HealthDay reports.

According to the news source, researchers found that often times the condition lasted for more than a month after the patient was discharged from the hospital and led to worse outcomes, including death.

"This is not just a lab abnormality," study senior author Dr. Mikhail Kosiborod, a cardiologist with St. Luke's Hospital Mid-America Heart & Vascular Institute, said in recent statement "These patients actually feel worse after they leave the hospital. Mortality is higher, too."

According to the National Library of Medicine, anemia occurs when the body does not have enough healthy red blood cells to function properly. The lack of cells leads to deprived oxygen in bodily tissues.

Previous research done on the topic had found that roughly half of heart attack patients who were discharged from the hospital left with much lower hemoglobin counts than when they were admitted, but most of the patients that were studied did not encounter bleeding complications that typically cause the condition, the news provider stated.

This discovery led Kosiborod and his team of researchers to hypothesize that the anemia developed by heart attack patients was actually caused by the amount of blood drawn from them during the several blood tests taken during treatment.

"Drawing blood in a hospital is typically a very common occurrence, particularly in the intensive care unit," Kosiborod said.

In their research, the team studied the medical records of nearly 18,000 patients who had experienced and been treated for a heart attack in 57 hospitals across the country. The study authors found that while all the patients were recorded as having a normal level of red blood cells upon hospital admission, 20 percent left the hospital with moderate-to-severe anemia. Further analysis revealed that the risk of anemia rose 18 percent for each 50 milliliters of blood taken.

"That was probably somewhat more than what we initially expected to find," Kosiborod stated.

On average, each patient had 173.8 mL of blood drawn to be used for testing, equating to half a unit of whole blood. Patients who did not develop moderate-to-severe anemia gave up about 100 mL of blood less than those who did develop the condition, according to HealthDay.

The amount of blood drawn differed from patient to patient, but also differed between hospitals, prompting Kosiborod to believe that the variation in post-discharged anemia prevalence was due to the "hospital-based processes of care."

The authors of the study offered relatively simple solutions to the problems found in their research, suggesting that a few solutions could stop the problem, including adopting the use of smaller pediatric tubes when drawing blood, instead of the full-sized adult tubes, HealthDay reported.

"Pediatric tubes are perfectly adequate for most of the tests that need to be done and can drastically reduce the amount of blood lost," said Kosiborod.

Also noted in the report was that taking blood less frequently would be an appropriate response, or even re-using blood that had been previously drawn for multiple tests.

Other doctors have concurred with Kosiborod that drawing less blood may be necessary in the future of blood tests, as the process is as expensive as well.

"If you put the cost together with the issue of the hazard of patients developing hospital-acquired anemia, that's pretty profound," said Dr. Stephanie Rennke, assistant clinical professor of medicine at the University of California, San Francisco.