AS9.3-4 | Perioperative Fluid Therapy and Blood Product Use — Summary & Reflection

KEY TAKEAWAYS

Perioperative fluid therapy (AS9.3) is governed by three principles: choose the right fluid type (balanced crystalloids as default; colloids selectively; blood products for deficit replacement), give the right volume (guided by goal-directed fluid therapy using dynamic parameters SVV/PPV rather than fixed volume prescriptions), and monitor continuously (urine output, MAP, lactate, CVP). Normal saline causes hyperchloraemic acidosis in large volumes; Hartmann's and Plasmalyte are balanced alternatives. Blood product therapy (AS9.4) requires understanding of four components: PRBCs (Hb <7 g/dL threshold, or haemodynamic instability with active haemorrhage); FFP (INR >1.5 with bleeding; massive transfusion 1:1 ratio); platelets (count <50,000/µL with bleeding); and cryoprecipitate (fibrinogen <1.5 g/L). Each product has specific storage, dosing, and compatibility requirements. Adverse effects range from febrile reactions (FNHTR — benign) to AHTR (ABO incompatibility — potentially fatal), TRALI (non-cardiogenic pulmonary oedema from donor antibodies), and TACO (hydrostatic overload). Mandatory pre-transfusion bedside identity verification prevents the majority of fatal haemolytic reactions.

REFLECT

Consider the clinical scenario from the hook: 2 litres of blood loss in 30 minutes, Hb 5.8 g/dL, INR 2.1, platelets 48,000/µL. Now that you have worked through this SDL, sketch the blood product orders you would issue and in what sequence. Which component is most urgently needed, and why? What dynamic parameter would you use to guide crystalloid boluses alongside the blood products? How does the 1:1:1 damage-control ratio apply here, and what are its limitations? Discuss your reasoning with a classmate — articulating a management plan aloud, and being challenged on it, is one of the most effective ways to consolidate the clinical reasoning that this SDL has introduced.