Patient selection: surgical patient
Assumption: blood lost during and after surgery is collected in the suction cannisters
Parameters:
(1) volume in suction containers in liters at 24 hours
(2) hemoglobin concentration of the fluid in the suction container in g/dL at 24 hours
(3) volume in suction containers in liters at 48 hours
(4) hemoglobin concentration of the fluid in the suction container in g/dL at 48 hours
(5) usual blood volume in liters
(6) hemoglobin concentration in g/dL prior to surgery
(7) hemoglobin concentration in g/dL at 24 hours after surgery
(8) hemoglobin concentration in g/dL at 48 hours after surgery
estimated blood loss at 24 hours =
= ((hemoglobin preop) – (hemoglobin at 24 hours)) / (hemoglobin preop) * (blood volume)
postoperatve blood loss score in liters at 24 hours=
= (0.822 * (suction container volume)) + (0.0706 * (suction container hemoglobin concentration)) + (0.0821 * (estimated blood loss at 24 hours)) – 0.536
estimated blood loss at 48 hours =
= ((hemoglobin preop) – (hemoglobin at 48 hours)) / (hemoglobin preop) * (blood volume)
postoperatve blood loss score in liters at 48 hours=
= (0.791 * (suction container volume)) + (0.06886 * (suction container hemoglobin concentration)) + (0.122 * (estimated blood loss at 48 hours)) – 0.54
If more than one suction container is present then either (a) the fluid needs to be combined and sampled or (b) the blood loss represented by each container must be added up for a total. The presence of a blood clot also needs to be taken into account.
