Establishment of Optimal Transfusion Threshold During Spine Surgery

Study Overview
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Brief Summary
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The purpose of this study is to determine whether a higher threshold for transfusion with red blood cells improves the tissue oxygenation.

Official Title
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Establishment of Optimal Transfusion Threshold During Spine Surgery

Conditions
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Anemia, Spine Surgery

Intervention / Treatment
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* Other: Allowed drop in hemoglobin to level between 4,5-5,6 mmol/L
* Other: Allowed drop in hemoglobin to level between 5,6-6,5 mmol/L


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 18 years or older Patients undergoing spine surgery Be legally competent Read and understand Danish Exclusion Criteria: Present malignant disease Previously apoplexia cerebri Known heart disease with functionality equivalent to NYHA II or CCS II or worse

Ages Eligible for Study
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Minimum Age: 18 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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Design Details

Primary Purpose: Supportive Care
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Allowed drop in hemoglobin to 4,5-5,5 mmol/L<br>Transfusion with red blood cells to level between 4.5-5.5 mmol/L | Other: Allowed drop in hemoglobin to level between 4,5-5,6 mmol/L<br>* Transfusion with red blood cells to hemoglobin level between 4,5-5,5 mmol/L<br>|
| Experimental: Allowed drop in hemoglobin to 5,5-6,5 mmol/L<br>Transfusion with red blood cells to level between 5.5-6.5 mmol/L | Other: Allowed drop in hemoglobin to level between 5,6-6,5 mmol/L<br>* Transfusion with red blood cells to hemoglobin level between 5,6-6,5 mmol/L<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The change in subcutaneous oxygen tension from incision. | The primary endpoint is the change in subcutaneous oxygen tension from incision until the time most patients is still undergoing surgery. Subcutaneous oxygen tension is measured every fifteen minutes throughout surgery. The oxygen tension is measured with a polygraphic electrode (Clark's electrode). | Every fifteen minutes throughout surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Oxygenation of the brain |  | Every fifteen minutes throughout surgery | 
| The concentration of lactate in plasma |  | Every half an hour throughout surgery | 
| Variation in the ST-segment of the ECG |  | Every fifteen minutes throughout surgery | 
| Muscular saturation of the deltoid muscle | The change in muscular saturation from incision until the time when most patientes are still undergoing surgery. Furthermore the lowest measured and the last measured muscular saturation is also evaluated. | Every fifteen minutes throughout surgery | 
| The change in subcutaneous oxygen tension from incision. | The lowest measured subcutaneous oxygen tension and the last measured subcutaneous oxygen tension throughout surgery. | Every fifteen minutes throughout surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Anemia, Tissue oxygenation, Spine surgery