Bloodless Strategies

"Proper management of the severely anemic patient refusing blood therapy requires an astute clinician who understands the patient's philosophy and appreciates the often conflicting medicolegal and ethical aspects of their care, as well as the therapeutic options that are currently available. In caring for such patients, the clinician should heed the wise advice of William Osler, who once said it was more important to know 'what sort of person has the disease than what sort of disease the person has'" (MC Mann et Al., Ann Int Med 117:1042, 1992)
 
 
 
There is not a transfusion trigger (1)
1
Patients can tolerate very low hemoglobin concentrations.  Recent research has made a universal transfusion trigger passe.
  • "The data preclude any scientific conclusion in support of a safe Hb concentration or transfusion trigger. However, clinicians may be reassured by the absence of mortality due to anemia in patients with Hb concentrations between 5 and 7 g per dL (50 and 70 g/L)"
  • "The possibility of survival with severe anemia,... is supported by the experience of one author who stated that 73 patients with preoperative Hb concentrations < 5 g per dL (50 g/L) underwent surgery without subsequent mortality"
  • "Survival is possible at extremely low oxygen-carring capacity - Hb concentrations as low as 1,4 g per dL (14 g/L)".
Transfusion 34:396-401, 1994
 
  • "Acute isovolemic reduction of blood Hb concentration to 50 g/L in conscious healthy resting humans does not produce evidence of  inadequate systemic TO2, as assessed by lack of change of VO2 and plasma lactate concentration. Analysis of Holter readings suggests that at this Hb concentration in this resting healthy population, myocardial ischemia would  occur infrequently." 
JAMA. 1998;279:217-221
 

  • "In summary, we found that reducing DO2 to 7.3 ± 1.4 ml O2 · kg–1 · min–1 by acute isovolemic anemia (hemoglobin = 4.7 ± 0.2 g/dl) plus an infusion of a -adrenergic antagonist in resting healthy adults aged 19–25 yr does not produce evidence of inadequate systemic oxygenation. This extends our previous finding and suggests that the decreased DO2 associated with a hemoglobin concentration of 4.5–5 g/dl is well-tolerated by conscious, healthy, young, resting adults"

ANESTHESIOLOGY 2000;92:407-413
Don't delay the operation, if it is necessary
2
Operation should not be delayed in the actively bleeding patient who refuses blood transfusion.
  • "In our series of actively bleeding Jehovah's Witnesses, initial conservative treatment with delayed surgery led a 75% mortality rate compared with a 20% mortality rate in patients who underwent emergency operation within 24 hours of admission to the hospital"
  • "When blood loss was below 500 mL, no patients died, regardless of preoperative hemoglobin levels"
Arch Surg 127:349-351, 1992
 

Minimizing perioperative phlebotomies
3
Use blood-oxygen monitoring devices and techniques that limit blood sampling 
  • One recent study of intensive-care-unit patients with in-dwelling arterial lines found that they were phlebotomized an average of four times a day, resulting in a mean blood loss during their total hospital stay of almost 1 litre
  • To limit blood sampling:
    • transcutaneous pulse oximeter
    • pediatric microsampling equipement
    • multiple tests per sample
N Eng J Med 1986; 314:1233-5
Minimizing blood loss during the intervention
4
There are many ways to reduce blood loss in surgery 
  • Hemodiluition (2)
  • Intraoperative blood salvage (3)
  • Hypotensive anestesia (4)
  • Induced hypothermia (5)
  • Hemostatic agents (6)
  • Meticolous hemostasis
  • Preoperative planning
Ann Int Med 117:1044, 1992
Maximizing blood production

5

Ways to increase blood production

  • Recombinant erythropoietin (7)
  • Iron 
  • Folate and Vitamin B12
  • Total parenteral nutrition
Ann Int Med 117:1045, 1992
Maximizing cardiac output

6 

Maintenance of circulating blood volume and, therefore, cardiac output.
  • Crystalloid solutions
  • Plasma volume expanders
Ann Int Med 117:1046, 1992
Increasing oxygen content

7 

Maximum oxygen availability must be maintained
  • "Normally, oxygen content of blood depends mostly on oxygen bound to hemoglobin, with only a small amount (1% to 2%) composed of dissolved oxygen. In severely anemic patients, however, dissolved oxygen may contribute up to 25% of the oxygen content"
    • High concentration of oxygen with mechanical ventilatory support
    • Hyperbaric chamber
  • "The development of an effective blood substitute (8) would be a 'special boon to Jehovah's Witnesses'"
    • Fluorocarbon emulsions
    • Hemoglobin Based Oxygen Carriers (HBOC)
Ann Int Med 117:1046, 1992 
Decreasing metabolic rate

8 

 Procedures used in severely anemic patients to minimize oxygen consumption.
  • Deliberate mild hypothermia
  • Neuromuscular blocking agents with sedation and ventilatory support
Ann Int Med 117:1047, 1992
 
 

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