What causes anaemia in surgery patients?

Anaemia may be present before surgery, especially in people with chronic or oncological diseases, or who suffer from poor food absorption, significant metrorrhagia, nutritional deficiencies (elderly people), gastric ulcers, etc.

In patients who have previously undergone surgery, intraoperative bleeding during the surgical procedure, blood collected by drains, and repeated extractions (in critically ill patients) can exacerbate this level of anaemia.