Intraoperative Estimated Blood Loss, Blood Transfusion, and Postoperative Clinical Outcomes in Patients Undergoing Non Cardiac Surgery, Siriraj Hospital

One of the worldwide health problems that covers more than a quarter of the population is anemia. The World Health Organization (WHO) recommendations use of hemoglobin concentration for diagnosing anemia as hemoglobin (Hb) level \<12 g/dL and \< 13 g/dL for women and men, respectively. The most of anemic patients caused by iron deficiency anemia (IDA), followed by the anemia of chronic disease (ACD).

Iron deficiency anemia often result from malnutrition status, acute or chronic blood loss such as perioperative blood loss. Chronic kidney disease is the primary cause of anemia of chronic disease, followed by acute or chronic inflammatory conditions, or in patients with malignancies.Currently, there are lack of preoperative evaluation, diagnostic methods, and adequate treatments for anemia before attaining elective non cardiac surgery. Baron et al retrospective study the European Surgical Outcome included 39,309 patients from 28 European countries. The prevalence of anemic patients was about 26.5% in women and 31.1% in men. The higher rate of prolonged hospital administration (P = .0001) and transferred to intensive care unit (P = .001) in moderate to severe anemic patients. Moreover, anemic patients who undergone cardiac surgery and non-cardiac surgery showed a higher mortality than nonanemic patients.

Preoperative hemoglobin level was used with other factors such as demographic data, surgical procedures, and anesthetic technique to increase predictive accuracy of perioperative blood transfusion. The mortality rate raised in anemic patients who received blood transfusion in perioperative period. Criteria for blood transfusion had various factors. The important factor which usually used is hemoglobin level: Liberal strategy suggested starting blood transfusion when Hb level below 9-10 g/dL, another method was Restrictive strategy that starting blood transfusion if Hb level below 7-8 g/dL. In addition, the hemoglobin threshold cut-off point level often differed due to the objective for each study.Althrough many organizations tried to develop standard protocol for blood transfusion, the universal transfusion threshold level cloud not properly use for all patients.Blood transfusion remained the cornerstone of the treatment of anemia but intraoperative period inappropriately transfused blood component causing risk of post operative complication, 30-days mortality, increasing length of hospital stay, and transferring to intensive care unit.

Moreover, The National Blood Authority studied about types of operation and operation at risk for blood transfusion that had operative time more than 2 hours and estimated blood loss more than 500 ml, needed to receive blood transfusion before surgery. The American College of Cardiology had found various factors affecting peri-operative blood transfusion risk but they were not practical to use in real-life practice.

After review literature, Siriraj hospital has not unanimous protocol to guide proper preoperative anemia and blood transfusion. This retrospective study will review non-cardiac surgery cases and collect data such as demographic data, surgical procedures, anesthetic techniques, preoperative hemoglobin level, intraoperative estimate blood loss, blood transfusion, and post operative complication in Siriraj hospital which has many patients undergo various operations. This study can be model to develop preoperative anemia management guideline in Siriraj Preanesthesia Assessment Center (SIPAC), Siriraj hospital and reduce risk and adverse outcomes after blood transfusion in the future.