Allogenic Blood Transfusion During Elective Open Abdominal Aortic Surgery

Study Overview
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Brief Summary
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Open surgery on the abdominal aorta is a high risk procedure associated with an intravascular volume blood loss and thereby, with high requirement for blood and blood product transfusion. The aim of this study was to establish the rate for allogenic blood transfusion (ABT) during elective open abdominal aortic surgery and find parameters associated with ABT requirements.

Detailed Description
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Two distinct clinical entities affect the abdominal aorta: abdominal aortic aneurysm (AAA) and aortoiliac occlusive disease (AIOD). These are multifactorial vascular disorders caused by complex genetic and environmental factors. Older patients with more comorbidity are often affected. Open abdominal aortic surgery is associated with high mortality rate. Even in specialised institutions it varies from 2 to 5%. Similar results can be compared to mortality for coronary artery bypass grafting. This reflects the complexity of the surgery and the general health of those patients. It is associated with intravascular volume blood loss and, thereby, with a high requirement for blood and blood products transfusion. Allogenic blood transfusion (ABT) has been associated with an increased risk of tumour recurrence, postoperative infection, acute lung injury, perioperative myocardial infarction, postoperative low-output cardiac failure, and increased mortality. In the last decades, multiple strategies have been undertaken to prevent massive intraoperative blood loss during elective surgery and allogenic blood transfusion requirement. One of the method advocates a preoperative increase in red blood cells level using B12, folic acid and iron supplements or with erythropoietin usage. Other methods involve the optimisation of surgical technique and the use of a machine for intraoperative blood salvage, known as cell saver. The aim of this study was to establish the rate for ABT during elective open abdominal aortic surgery, find parameters associated with ABT requirements, and optimise the investigators hospital's maximum surgical blood ordering schedule (MSBOS).

Official Title
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Allogenic Blood Transfusion During Elective Open Abdominal Aortic Surgery and Its Predictors: a Retrospective Database Study at a Tertiary Hospital in Croatia

Conditions
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Blood Transfusion

Intervention / Treatment
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* Other: Allogenic blood transfusion (ABT)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients older than 18 years Elective open abdominal aortic surgery Abdominal aortic aneurysm repair Abdominal aortic bypass grafting for occlusive aortoiliac disease Exclusion Criteria: Patients younger than 18 years Patients undergoing cardiac surgery Patients with ruptured abdominal aneurysms Patients undergoing endovascular aortic repair Patients submitted to other types of vascular surgery (i.e., carotid endarterectomy or peripheral bypass surgery)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 90 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Transfused group (TR)<br>Group received allogenic blood transfusion (ABT) alongside with autologous blood from intraoperative cell saver (ICS) during elective open abdominal aortic surgery. | Other: Allogenic blood transfusion (ABT)<br>* During elective open aortic surgery, the autologous blood from ICS was processed and re-transfused in all patients. However, TR group additionally received ABT.<br>|
| Non-transfused (non-TR)<br>Group received only autologous blood from intraoperative cell saver (ICS) during elective open abdominal aortic surgery. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Overall ABT requirement | Overall ABT requirement (in %) during elective abdominal aortic surgery with the use of ICS for intraoperative blood salvage and autologous transfusion. | Retrospective analysis, 6-year period | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Age as the predictor of higher ABT requirement | (years) | Retrospective analysis, 6-year period | 
| Gender as the predictors of higher ABT requirement | male/female | Retrospective analysis, 6-year period | 
| Body mass index (BMI) as the predictors of higher ABT requirement | BMI (kg/m2) | Retrospective analysis, 6-year period | 
| Body surface area (BSA) as the predictors of higher ABT requirement | BSA (m²) | Retrospective analysis, 6-year period | 
| Total blood volume as the possible predictors of higher ABT requirement | TBV (in liters) calculated trough Nadler's formula | Retrospective analysis, 6-year period | 
| Hemoglobin (Hb) and hematocrit (Htc) as the predictors of higher ABT requirement | Hb (g/L) and Htc (%) | Retrospective analysis, 6-year period | 
| Type of illness as the predictor of higher ABT requirement | abdominal aortic aneurysm or aortoiliac occlusive disease | Retrospective analysis, 6-year period | 
| Patient's comorbidities as the predictors of higher ABT requirement | arterial hypertension, coronary artery disease, diabetes, atrial fibrillation, cerebrovascular incidents, chronic obstructive pulmonary disease, chronic renal insufficiency, malignancy | Retrospective analysis, 6-year period | 
| Medications that impair coagulation and homeostasis as the predictor of higher ABT requirement | acetylsalicylic acid, clopidogrel, or warfarin | Retrospective analysis, 6-year period | 
| Postoperative duration of mechanical ventilation | (hours) | Retrospective analysis, 6-year period | 
| Length of stay (LOS) | LOS in ICU (days) and overall hospital LOS (days) | Retrospective analysis, 6-year period | 
| In-hospital mortality rate | (in %) | Retrospective analysis, 6-year period | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Aorta, abdominal, Intraoperative blood salvage, Elective surgical procedures, Patient outcomes assessment