Episode 15: Blood transfusions
Author: Thong Yi Kun
Editor: Dr. Suneet Sood
Narrators: Thong Yi Kun, Alan Koay
You hurry past the patient diagnosed with intrabdominal bleeding in Bed 1. Extra beds have been placed in the Emergency Department, making the already packed ED even more crowded. Finding your way to the back entrance amongst the crowd of medical staff, your spot your patient, who is just being wheeled back from radiology.
You are a registrar in a small town surrounded by palm oil plantations. You are four hours away from the nearest major hospital. An hour earlier, a bus full of plantation workers had crashed into a tree at high speed. The tens of injured workers were brought to the nearest hospital – your hospital.
Your patient, Halim, is a 23-year-old male. Flipping through his X-rays confirms your diagnosis of bilateral femur fractures. When you first saw him, his thighs were obviously deformed. After assessing him and excluding other serious injuries, you send him off to radiology, asking for immediate X-rays. Before sending him off, you start a saline infusion at high speed, insert an indwelling urethral catheter, splint the fractures, give painkillers, and send an urgent requisition for blood. Halim’s wife stands by, sick with worry.
Coming out of radiology fifteen minutes later, Halim seems more confused and lethargic than before. His heart rate has risen from 110 to 150. He is tachypnoeic, cold and clammy, and capillary refill is obviously prolonged. His blood pressure has dropped from 120/80 to 80/50. By your estimation, this is class 4 haemorrhagic shock.
Just then, your intern comes running up. She has been talking to the blood bank.
“The patient’s blood group is A-. The blood bank says there’s no A- blood.”
“Tell them to give me O negative blood then. Hurry.”
“I asked. We’re out of that too. Our last unit was given to the patient with intraabdominal bleeding. We are left with A+, B+ and B- blood only. The blood bank technician says they’ve called the national blood bank for more, but it’ll take at least 4 hours to get more blood.”
You look at Halim’s wife.
“ What’s going to happen doctor?”
“Has he ever received a transfusion before?”
You turn to the intern.
“There’s no option. Get me four units of the A+ blood then”, you order.
“What! But the patient is A-?”
“I’ll explain later. Just hurry.”
Four hours later Halim has been stabilized, and has come out of surgery for internal fixation of the femur fractures. As you sit in the doctors’ room, coffee in hand, your intern tries her luck.
“How come you gave A+ blood to an A- patient? Won’t he get a transfusion reaction?”
“I, er, think so,”
“Well, er, mismatched transfusion results in reactions.”
“Mismatched ABO transfusion results in reactions. This is because persons with blood group A already have antibodies to B antigens, and vice versa. If you had transfused B blood to this man, the anti-B antibodies in his blood would have destroyed all the transfused blood. In contrast, mismatched Rh transfusions do not cause reactions, at least not the first time. This man has no anti-Rh antibodies, because he has never been exposed to the Rh antigen.”
“So, he will develop antibodies to Rh now?”
“Yes, of course. This means that now, he can never ever receive an A+ transfusion. If he does, he will have a severe transfusion reaction.”
“So how come he has anti-B antibodies in the blood, if he has never received a transfusion?”
You start thinking about the reasons:
Shared antibodies with food and bacterial polysaccharide antigens that result in the development of anti-A and anti-B in infancy. You start thinking how fortunate it is that it was Halim who received the A+, not his wife. If she had been A- and had received an A+ transfusion, her chances of bearing babies would have been affected.
You smile and give your usual reply;
“I don’t know. Why don’t you look it up and tell me?”
Kruskall MS, Mintz PD, Bergin JJ, Johnston MF, Klein HG, Miller JD, et al. Transfusion therapy in emergency medicine. Annals of emergency medicine. 1988;17(4):327-35.
Venkata Raman B, Sravani B, Phani Rekha P, Lalitha KVN, Narasimha Rao B. Effect of plant lectins on human blood group antigens with special focus on plant foods and juices. International Journal of Research in Ayurveda and Pharmacy 2012;3(2):255-63, available at http://www.ijrap.net/admin/