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:

* 1. Hemoglobin concentration ≤ 95 g/L, while in PICU
* 2. Not already participating to a randomized controlled trial on hemoglobin threshold to guide red blood cell transfusion practice

Exclusion Criteria:

1. Post conception age ≤ 36 weeks or \> 18 years at PICU entry
2. Refusal of consent by patient and/or parent
3. Uncorrected cyanotic cardiac disease, univentricular physiology
4. Sickle cell disease
5. Brain Death
6. Extracorporeal membrane oxygenation (ECMO)
B: Inclusion Criteria:

1. Age ≥18 years old at time of SAH
2. First ever episode of aneurysmal SAH
3. Diagnosis of aSAH as confirmed by treating physician (eg: neurosurgeon or neuro- interventionalist) and supported by blood in subarachnoid space (e.g. cranial imaging or cerebrospinal fluid positive for xanthochromia, surgical visualization) that is the result of a ruptured aneurysm (e.g. direct visualization, cranial imaging or catheter angiogram)
4. Hb ≤100g/L within 10 days following aSAH (defined by first day of hospital presentation)

Exclusion Criteria:

1. Physician and or family decision to withdraw/withhold active medical care at time of enrolment
2. Active bleeding with hemodynamic instability at time of enrolment
3. Patients with contraindication or known objection to blood transfusions
4. SAH due to mycotic aneurysm, infundibulum and vascular malformations.
C: Inclusion Criteria:

* Males and females older than 18 years of age who have postoperative Hb \< 10gm/dl within 15 days after the index operation
* Patients who undergo an operation in either one of the three following categories:

  * Veterans who undergo PAD - related operations including but not limited to the following:

    * aortobifemoral or aortobiiliac bypass
    * open abdominal aortic aneurysm repair with simultaneous repair of aortoiliac occlusive disease
    * visceral bypass
    * iliofemoral bypass
    * femoral bypass or endarterectomy
    * infrainguinal bypass
    * thromboembolectomy
    * supra-aortic trunk bypass or endarterectomy
    * carotid endarterectomy
    * major lower extremity amputations (transfemoral, through the knee, or transtibial)
  * Veterans with past medical history of ischemic stroke or IHD or PAD who undergo the following general surgery procedures, defined as:

    * known prior MI
    * ECG findings consistent with prior MI
    * prior percutaneous coronary intervention
    * prior coronary artery bypass surgery
    * history of angina for which the patient is currently receiving treatment
    * stress test indicating myocardial ischemia
    * who undergo the following General Surgery operations:

      * Open cholecystectomy or other complex biliary reconstruction
      * such as open common bile duct exploration for stones
      * reconstruction as part of oncologic operations such as palliative pancreatic cancer procedures)
    * small bowel resection
    * pancreatectomy
    * colon resection
    * rectal resection
    * splenectomy
    * transhiatal esophagectomy
    * liver resection
    * gastric resection
    * open ventral hernia repair
    * Colostomies (reversals and takedowns)
    * Intestinal anastomosis takedowns and revisions
    * Gastric bypass
    * Adrenalectomies
    * Major diaphragmatic hiatal hernia repairs
  * Veterans with past medical history of ischemic stroke or IHD or PAD who undergo the following Vascular Surgery operations:

    * Open aneurysm repair, including but not limited to:

      * carotid
      * subclavian
      * abdominal aortic
      * iliac
      * femoral
      * popliteal aneurysms
    * and complex endovascular aneurysm repair, defined as:

      * fenestrated endograft
      * or endograft with need for iliac conduit
      * or endovascular aneurysm repair with simultaneous femoral artery reconstruction or bypass
    * Subclavian/vertebral bypasses and transpositions
* Patients undergoing the above procedures will be included in the study regardless of their preoperative Hb level, and regardless of preoperative or intraoperative transfusion they might have received.

Exclusion Criteria:

* Veteran unable to consent
* Veteran unwilling to follow protocol (such as Jehovah's witnesses)
* Veteran with known history of hereditary anemias such as Thalassemia or Sickle cell disease
* Veteran with known history of hereditary bleeding disorders, such as factor VIII or factor IX deficiency
* Veteran with prior history of adverse reaction to blood administration, such as fever, rash, or hemolysis
* Veteran does not speak or understand English
* Veteran hemodynamically unstable or in cardiogenic shock for \>48 hours after the index procedure
* Veteran participating in another interventional trial whose objective is to evaluate the effect of transfusion on outcomes
* Pregnancy in female Veterans
* Veteran is a prisoner or in custody of law enforcement
* Prior randomization in the CSP#599
* Patients who are known to have tested positive for COVID-19 and have not recovered prior to consent will not be consented. Any participant who is known to have a positive COVID-19 test during the screening process and has not recovered will be excluded prior to randomization.
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