Palmer et al developed an algorithm for determining whether to transfuse a patient or not in the perioperative period.
(1) critical hemoglobin based on blood supply
(2) type of surgery
(3) expected pathology
(4) likelihood of bleeding (inexperienced surgeon or history of large blood loss)
(5) age of the patient
(6) comorbid conditions
(7) recent blood loss
(9) other risk factors
(10) units of blood available
(11) possibility of doing surgery later
(12) current hemoglobin
The critical hemoglobin is the point at which physiologic problems arise from a low hemoglobin. The threshold is affected by the local resources.
(1) The absolute lowest value is 4.0. This is used where blood supplies may be scant and/or potentially contaminated with HIV or other viral pathogen.
(2) The highest value is 6.0, for use in a developed country.
type of surgery
blood loss likely
likelihood of bleeding
high (inexperienced surgeon or history of large blood loss)
age in years
> 70 years
51 to 70
significant cardiac or respiratory disease
other significant medical problems
recent blood loss
other significant risk factors
age < 1 OR long surgery OR high altitude
units of blood available
possibility of delaying surgery
no (operation may not be possible again due to system failure)
total score =
= (current hemoglobin in g/dL) - (points for critical hemoglobin) + SUM(points for the other parameters)
• If the score is >= 0: Proceed to surgery if surgical candidate. No need to transfuse.
• If the score is < 0: Reduce risk factors for bleeding as much as possible. Consider transfusion if available.
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Specialty: Clinical Laboratory, General Surgery, Anesthesiology, Emergency Medicine, Critical Care