A 68-year-old man was admitted to Accident and Emergency with a 6-hour history of increasing abdominal pain and diarrhoea. He was a heavy smoker with a history of ischaemic heart disease. On examination he had a pulsatile mass present in his abdomen and no lower limb pulses. A computed tomography scan of his abdomen confirmed a leaking abdominal aortic aneurysm. Haemoglobin was 4 g/dl, white cell count 12 × 109/l, platelet count 432 × 109/l and coagulation screen was normal. Intra-operatively he lost approximately 10 litres of blood and was transfused 15 units of red cells. He also initially required large volumes of colloids to maintain his blood pressure. On the intensive therapy unit (ITU) post-operatively he was noted to be bleeding from drain sites at a rate that was higher than anticipated and was oozing from his arterial line and central venous pressure (CVP) line sites. Data from a repeat full blood count and coagulation screen were: haemoglobin 12 g/l, white cell count 16 × 109/l, platelet count 15 × 109/l, prothrombin time (PT) 22 seconds, activated partial thromboplastin time (APTT) 60 seconds, fibrinogen 0.8 g/l.
You are asked for your advice regarding the patient’s blood results. How would you manage this case?
Major bleeding, and consequently massive transfusion (MT), is a frequent complication of surgery. Massive transfusion is defined as replacement of one blood volume within a 24-hour period, the normal adult blood volume being about 7% of ideal body weight. Massively transfused patients show evidence of defective haemostasis in a high number of cases, but the incidence varies depending on the clinical context (blunt versus penetrating trauma, elective versus emergency surgery) and according to the definition of coagulopathy (clinical findings versus laboratory test results) and to the blood products administered to the patient. The cause of coagulopathy in MT is multifactorial, secondary to haemodilution of coagulation factors and platelets, disseminated intravascular coagulation (DIC), hypothermia, acidosis and hypocalcaemia.1
Haemodilution occurs following volume replacement with crystalloid or colloid and transfusion of red cells, and results in a reduction in the concentrations of platelets and coagulation factors. The level of fibrinogen is reduced first, with a level of 1 g/l after 150% blood volume loss, followed by a fall of coagulation factors to 25% activity after 200% blood loss. Prolongation of the APTT and PT to 1.5 times the mean normal values is associated with an increased risk of clinical coagulopathy. A platelet count of at least 50 × 109/l occurs when about two blood volumes have been replaced by fluid or red cells.
Disseminated intravascular coagulation is an acquired syndrome secondary to the systemic activation of coagulation. It is associated with the haemostatic defects related to the excessive generation of thrombin and fibrin and the excessive consumption of platelets and coagulation factors. This results in ...