Please select the eligibility criteria that correspond to the clinical trial below.
Title: The Transfusion Triggers in Vascular Surgery Trial: Two Different Transfusion Triggers for Postoperative Haemoglobin Separation and Adherence to Transfusion Strategies in Vascular Surgery: a Randomised Clinical Feasibility Trial
Brief Summary: BACKGROUND

* Vascular surgical patients often receive red blood cell (RBC) transfusions in the peri-operative period
* RBC transfusion may lead to improved outcome but on the other hand the intervention may be harmful
* Danish Health and Medicines Authority recommends transfusion of RBC at hemoglobin below 5 mmol/L while local clinical guidelines recommend transfusion of RBC to maintain hemoglobin levels above 6 mmol/L
* A large randomized clinical trial is needed to evaluate the efficacy and safety of RBC transfusion in patients undergoing vascular surgery.
* A trial examining the effect of RBC transfusion on tissue oxygenation is used to test the trial-design and feasibility for a trial evaluating post-operative mortality and morbidity.


Options:
A: Inclusion Criteria:

* Patients ≥ 70 years of age scheduled for intermediate- or high-risk non-cardiac surgery will be registered
* Registered patients will be randomised only if they indeed develop severe anaemia (if Hb level falls ≤ 9 g/dl) during surgery (=day 0) or day 1, 2, or 3 after surgery

Exclusion Criteria:

* preoperative Hb level ≤ 9 g/dl
* chronic kidney disease requiring dialysis
* suspected lack of compliance with follow-up procedures
* participation in other interventional trials
* expected death within 3 months
* inability to provide informed consent with absence of a legally authorised representative/ legal guardian
* temporary inability to provide informed consent
* previous participation in our trial
* patients who are prevented from having blood and blood products according to a system of beliefs (e.g. Jehovah's Witnesses)
* preoperative autologous blood donation.
B: Inclusion Criteria:

* Birth weight less than or equal to 1000 grams.
* Gestational age at least 22 weeks but less than 29 weeks
* Admitted to the NICU within 48 hours of life

Exclusion Criteria:

* Considered nonviable by the attending neonatologist
* Cyanotic congenital heart disease
* Parents opposed to the transfusion of blood
* Parents with hemoglobinopathy or congenital anemia
* In-utero fetal transfusion
* Twin-to-twin transfusion syndrome
* Isoimmune hemolytic disease
* Lack of parental consent
* Severe acute hemorrhage, acute shock, sepsis with coagulopathy, or need for perioperative transfusion.
* Prior blood transfusion on clinical grounds beyond the first 6 hours of life
* Infant has received erythropoietin prior to randomization, or is intended to receive erythropoietin through the neonatal course
* Congenital condition, other than premature birth, that adversely affects life expectancy or neurodevelopment.
* High probability that the family is socially disorganized to the point of being unable to attend follow-up at 22-26 months.
C: Inclusion Criteria:

* The patient remains in the ICU after 96 hours (4 days) or more following ICU admission
* The patient has required mechanical ventilation via an endotracheal tube or tracheostomy tube for 96 hours or more
* The patient is expected to require ≥24 hours of further mechanical ventilation at the time of assessment
* The patient is aged ≥55 years of age
* The patient has a Hb value of 90g/L or less at the time of assessment

Exclusion Criteria:

* Patient with active bleeding at the time of screening
* Patient with traumatic brain injury as presenting diagnosis
* Patient with intracranial haemorrhage as presenting diagnosis
* Patient not expected to survive the next 48 hours at the time of assessment.
* Patient objects to RBC transfusion
* Patient receiving concurrent treatment with erythropoietin or similar erythropoietic agent
* Follow up is not feasible
* Already enrolled in another RCT with similar clinical endpoints
D: Inclusion Criteria:

* Patients for planned open repair of the abdominal aorta or infrainguinal arterial bypass
* Hemoglobin \< 6 mmol/L

Exclusion Criteria:

* Documented wish against transfusion
* Previous serious adverse reaction with blood products
* Unable to understand the benefits and risks of testing
* Previous participation in trial

Answer: D