Fluid Management & Blood Products Flashcards

Goal-directed fluid therapy (GDFT) during major abdominal surgery primarily optimizes which hemodynamic endpoint?

Answer: Stroke volume or stroke volume variation

GDFT uses dynamic measures such as stroke volume optimization or stroke volume variation to individualize fluid administration and maximize cardiac output rather than targeting static filling pressures.

Permissive hypotension during damage control resuscitation for penetrating trauma targets which systolic blood pressure range in the absence of traumatic brain injury?

Answer: 80-90 mmHg

Permissive hypotension targets a systolic BP of 80-90 mmHg (MAP ~50-65 mmHg) to minimize ongoing hemorrhage by avoiding the hydraulic pressure that dislodges clots while maintaining minimum organ perfusion until surgical hemorrhage control.

Hypocalcemia during rapid massive transfusion occurs primarily because:

Answer: Citrate anticoagulant in blood products chelates ionized calcium

Blood products are anticoagulated with citrate, which chelates ionized calcium; during massive transfusion, citrate accumulates faster than hepatic metabolism can clear it, leading to hypocalcemia that impairs cardiac contractility and enzymatic coagulation.

The 'lethal triad' in trauma resuscitation, which creates a self-perpetuating cycle of worsening coagulopathy, refers to:

Answer: Hypothermia, acidosis, and coagulopathy

The lethal triad of hypothermia, acidosis, and coagulopathy is mutually reinforcing: hypothermia and acidosis impair enzyme function and platelet activity, worsening coagulopathy and hemorrhage, which deepens acidosis and heat loss.

During cardiopulmonary bypass, which test is the standard point-of-care method for monitoring adequacy of heparin anticoagulation, and what is the target value?

Answer: Activated clotting time (ACT) > 480 seconds

The activated clotting time (ACT) is the standard intraoperative test for heparin monitoring during CPB, with a target of > 400-480 seconds to prevent circuit thrombosis; it provides rapid bedside results without laboratory processing.

Transfusion-associated graft-versus-host disease (TA-GvHD), a frequently fatal complication in immunocompromised patients, is prevented by:

Answer: Gamma irradiation of cellular blood products

Gamma irradiation (or pathogen-inactivation technology) inactivates donor T-lymphocytes within cellular blood products, preventing them from engrafting in an immunocompromised host and launching a graft-versus-host immune attack.

In a patient with end-stage liver disease undergoing major hepatic resection, which coagulation test provides the most comprehensive assessment of overall hemostatic balance?

Answer: Viscoelastic testing (TEG or ROTEM)

Viscoelastic tests assess real-time whole-blood clot formation, strength, and fibrinolysis and reflect both procoagulant and anticoagulant deficiencies; PT/INR only measures procoagulant factors and systematically overestimates bleeding risk in liver disease because anticoagulant proteins are equally deficient.