Cooper University Hospital researchers studied the relationship between the age of the red blood cells and the development of nosocomial infections, testing 422 patients receiving blood transfusions. They found:
- A higher portion of blood is "old": “Previous data indicate that the average age of transfused blood is around 17 days old...[but in] our study, the average age of blood was 26 days, and 70% of all the blood transfused was older than 21 days."
- Not only did over 10% of patients die, but some had multiple nosocomial infections: "The analysis showed that 11 percent of patients died, while 57 patients (13.5 percent) developed NOSO: 32 patients developed one, 21 developed two, and 4 developed three."
- Those who did develop nosocomial infections had older blood: "Patients who developed NOSO had a significantly higher age of the “oldest” unit of blood (28.5 days vs. 32 days)."
- And the final conclusion: "Patients who received transfusions with blood that was 29 days or older were twice as likely to develop NOSO as those receiving transfusions with blood stored for 28 days or less."
Some fear that strict regulations regarding blood donation and storage will result in a dangerous shortage. More research is what is necessary for an answer to this problem.