Acute clinical hypocalcemic myocardial depression during rapid blood transfusion and postoperative hemodialysis: a preventable complication
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Rapid blood transfusions, even with CPD blood, significantly reduce ionized calcium, causing myocardial depression. Simultaneous calcium administration prevents this effect during transfusion and hemodialysis.
Area of Science:
- Cardiology
- Nephrology
- Transfusion Medicine
Background:
- Rapid transfusion of citrate-anticoagulated (ACD) blood can cause myocardial depression due to calcium binding.
- This hypocalcemic effect can also occur during hemodialysis with ACD blood prime and low calcium dialysate in patients with myocardial damage.
- Current practice often delays or omits calcium administration during these procedures.
Purpose of the Study:
- To investigate the impact of rapid transfusion of citrate phosphate dextrose (CPD) blood on ionized calcium levels.
- To compare the myocardial depressive effects of CPD and ACD blood.
- To evaluate the efficacy of simultaneous calcium administration in preventing hypocalcemia and myocardial depression during blood transfusions and hemodialysis.
Main Methods:
- Testing the hypothesis that rapid transfusion of CPD blood significantly reduces ionized calcium.
- Assessing the depressive effects of CPD blood compared to ACD blood.
- Evaluating the safety and efficacy of simultaneous calcium administration during transfusions and hemodialysis with modified dialysate calcium levels.
Main Results:
- Rapid transfusion of CPD blood significantly reduces ionized calcium levels.
- The myocardial depression caused by CPD blood is comparable to that of ACD blood.
- Simultaneous calcium administration effectively prevents myocardial depression during transfusions of both ACD and CPD blood.
- Adding calcium to the extracorporeal blood prime prevents initial depression during hemodialysis.
- Normocalcemic dialysate prevents hemodynamic instability during dialysis.
Conclusions:
- Rapid blood transfusions, including CPD blood, lead to significant reductions in ionized calcium.
- Simultaneous calcium administration is crucial for preventing myocardial depression during rapid blood transfusions.
- Hemodialysis in cardiac surgery patients is safe when calcium is added to the blood prime and dialysate is normocalcemic.
Abstract:
Despite experimental evidence that myocardial depression resulting from rapid transfusion of ACD blood (citrate binds ionic calcium) is avoidable by simultaneous calcium administration, most hypovolemic patients receive calcium either after transfusion or not at all. Similar iatrogenic hypocalcemic myocardial depression occurs in normovolemic patients with known myocardial damage who are dialyzed for acute uremia when ACD blood prime is used at high initial flow rates (350 c.c. per minute) and when dialysis is performed against low calcium dialysate (2.5 mEq. per liter or less). This study tests the hypotheses that (1) rapid transfusion of as little as one unit of CPD blood causes a significant reduction in ionized calcium, (2) the depressive effect of CPD blood is significant and similar to that of ACD blood, (3) rapid blood transfusion (ACD or CPD) is safe if calcium is given simultaneously, (4) addition of calcium to the extracorporeal heparinized blood prime used in dialysis prevents initial depression, and (5) hemodynamic instability during dialysis is prevented when the dialysate is normocalcemic. From the results of our study, we made the following conclusions: (1) Ionized calcium is reduced significantly by rapid transfusion of CPD blood; (2) acute myocardial depression noted with CPD blood is similar to that previously observed with ACD blood and is prevented during transfusion of either type of blood by simultaneous calcium administration; and (3) hemodialysis in patients who have had cardiac surgery is safe if calcium is added to blood prime and dialysate is made normocalcemic.