Assessment of intraoperative blood transfusion practices during elective surgeries in a tertiary care hospital

Introduction: Blood transfusion is often required in majorsurgeries. It is a scarce resource. Also, allogenic blood transfusion inassociated with many potential adverse effects. They include acute and delayedhemolytic reactions, infections, fluid overload and many others. Therefore itis crucial that blood transfusion is done judiciously. A critical approach isrequired where blood transfuion is concerned so as to minimize the adverseeffects to the patient. Studies have looked at perioperative blood transfusionpractice and have identified inappropriate transfusion rates between 19 and 53%1-5. It has been identified that audits regarding blood transfusionpractices may help to identify problems in blood tranfusion practice and helpto control and decrease rates of inappropriate transfusion 2-4, 6-8.Perioperative blood transfusion is defined as transfusion of RBCs (packed cellsor whole blood) during or within 24 hours after surgery.  Based on ASAguidelines, a patient will be considered overtransfused if the post transfusionpostoperative haemoglobin concentration is more than 10g%.This cut-offis based on the ASA guidelies , which suggest that patients with Hb more than10g% almost never need transfusions9.   This study is a prospective observationalstudy to observe the existing perioperative blood transfusion practices in ourtertiary care institute.

Aims and Objectives: The aim of this study is to evaluatethe existing  perioperative bloodtransfusion practices and the appropriateness of transfusion.

Primary Objective: To ascertain the common indicationsfor which the anaesthesiologists start perioperative blood transfusion and therates of intraoperative blood overtransfusion.

Secondary Objective: To assess variation in the bloodtransfusion practices from the standard guidelines.

**Methodology:**After Ethics Committeapproval and informed consent  fromanaesthesiologists of the department at GSMC & KEMH, the prospective study wouldbe done over a period of 6 months. Operation theatre anesthesiologists will begiven a form to complete for each patient given blood transfusion duringelective surgery. The form will ask indications for which they deemed fit totransfuse blood intraoperatively- whether the triggering factor was pallor,hypovolemia, hemodynamic instability, blood loss , haemoglobin level, surgeon’srequest or any other reasons.It would include details of the intraoperative bloodloss and fluid therapy given. Duringsurgery, two standard size gauze pieces are used.

Each fully soaked small gauze piece=20 ml

Each fully soaked large gauze piece=100 ml

Intraoperativeblood loss will be calculated by the gauze pieces used during surgery and bymeasuring the volume of blood in the suction bottle after deduction of anywashing fluid given during the surgery.

 Theimmediate post operative haemoglobin of the patient will be documented. Fromthe information obtained, the common indications for blood transfusion in ourhospital will be assessed. Based on the level of haemoglobin post operatively,the rate of appropriate blood transfusions will be evaluated. The variation inblood transfusion practices from the standard guidelines will be assessed. The standard indications for bloodtransfusion include:

1.     Blood loss greater than20% of blood volume when more than 100ml.

2.     Haemoglobin level lessthan 8 g/dl

3.     Haemoglobin level lessthan 10g/dl with major disease (e.g. emphysema, ischemic heart disease)

4.     Hemoglobin level less than10g/dl with autologous blood.

5.     Haemoglobin level lessthan 12g/dl and ventilator dependant. 9

Theprotocol and Case record form were discussed and approved by the professors ofthe department.

Study Design: It is a prospective observational study.

Inclusion Criteria: The anaesthesiologists(faculty and post graduate residents) in department at GSMC & KEMH who giveconsent for the study.

Bloodtransfusion given intraoperatively in elective surgeries.

Exclusion Criteria: Anaesthesiologists whorefuse consent for the study.

Statistical Analysis: Since this is an observational study,descriptive statistics will be used for the study population and will beexpressed as numbers (%) or mean. Chi square test will be used for comparingcategorical variables and P value of 0.05 or less considered significant.

Sample size will be 168 according to the formula:

n=Z2 pqN*e2(N-1)+Z2pq

where p= proportion percentage of the most common variable in thepopulation studies

q= 100-proportion

e= 5%

N= Total cases

Z=1.9