BCA Fluid Management & Blood Transfusion 1 — Questions and Answers
Question 1: Which crystalloid solution most closely resembles plasma electrolyte composition and is considered a balanced isotonic solution?
- 0.9% Normal Saline
- Lactated Ringer's solution (Correct answer)
- 5% Dextrose in Water (D5W)
- 3% Hypertonic Saline
Correct answer: Lactated Ringer's solution
Lactated Ringer's is a balanced isotonic solution containing sodium, chloride, potassium, calcium, and lactate in concentrations closest to plasma, making it a preferred choice for surgical fluid replacement.
Question 2: When comparing crystalloids to colloids for volume resuscitation, which statement best describes their volume distribution?
- Crystalloids distribute only intravascularly; colloids distribute throughout total body water
- Crystalloids distribute throughout extracellular fluid requiring a 3:1 replacement ratio; colloids remain primarily intravascular (Correct answer)
- Both crystalloids and colloids distribute equally throughout total body water
- Crystalloids distribute intracellularly while colloids distribute only extracellularly
Correct answer: Crystalloids distribute throughout extracellular fluid requiring a 3:1 replacement ratio; colloids remain primarily intravascular
Crystalloids distribute throughout the extracellular fluid compartment (intravascular + interstitial), so approximately 3 mL of crystalloid is needed to replace 1 mL of blood loss, while colloids exert oncotic pressure keeping fluid intravascular.
Question 3: According to current restrictive transfusion guidelines, what is the hemoglobin trigger for red blood cell transfusion in a stable, non-cardiac patient?
- Hemoglobin < 10 g/dL
- Hemoglobin < 8 g/dL
- Hemoglobin < 7 g/dL (Correct answer)
- Hemoglobin < 6 g/dL
Correct answer: Hemoglobin < 7 g/dL
Restrictive transfusion strategies supported by multiple RCTs recommend transfusion when hemoglobin falls below 7 g/dL in stable, non-cardiac patients, which has been shown to be non-inferior to liberal strategies.
Question 4: Transfusion-Related Acute Lung Injury (TRALI) is most commonly caused by which mechanism?
- ABO blood group incompatibility
- Bacterial contamination of the blood product
- Donor antibodies against recipient HLA or neutrophil antigens causing neutrophil activation in the lungs (Correct answer)
- Hyperkalemia from stored packed red blood cells
Correct answer: Donor antibodies against recipient HLA or neutrophil antigens causing neutrophil activation in the lungs
TRALI is most commonly caused by donor antibodies (anti-HLA or anti-neutrophil) that activate recipient neutrophils in pulmonary capillaries, leading to capillary leak and non-cardiogenic pulmonary edema within 6 hours of transfusion.
Question 5: Which colloid solution has been associated with increased renal dysfunction and mortality in critically ill septic patients, leading to restricted use in the ICU?
- Albumin 5%
- Hydroxyethyl starch (HES) (Correct answer)
- Gelatin-based solutions
- Dextran 40
Correct answer: Hydroxyethyl starch (HES)
The 6S and CHEST trials demonstrated that hydroxyethyl starch (HES) solutions were associated with increased rates of acute kidney injury requiring renal replacement therapy and increased 90-day mortality in septic patients compared to crystalloids.
Question 6: Using the Holliday-Segar 4-2-1 rule, what is the maintenance fluid rate for a 25 kg child?
- 65 mL/hr (Correct answer)
- 45 mL/hr
- 55 mL/hr
- 75 mL/hr
Correct answer: 65 mL/hr
The 4-2-1 rule calculates: 4 mL/kg/hr for the first 10 kg (40 mL/hr) + 2 mL/kg/hr for the next 10 kg (20 mL/hr) + 1 mL/kg/hr for remaining 5 kg (5 mL/hr) = 65 mL/hr.
Question 7: Which blood product contains the highest concentration of fibrinogen, factor VIII, factor XIII, and von Willebrand factor per unit volume?
- Fresh Frozen Plasma (FFP)
- Cryoprecipitate (Correct answer)
- Packed Red Blood Cells (pRBC)
- Platelet concentrate
Correct answer: Cryoprecipitate
Cryoprecipitate is prepared by slowly thawing FFP and collecting the cold-insoluble precipitate, resulting in a concentrated source of fibrinogen (150-250 mg/unit), factor VIII, factor XIII, vWF, and fibronectin in a small volume (~15 mL/unit).
BCA Fluid Management & Blood Transfusion 1
Which crystalloid solution most closely resembles plasma electrolyte composition and is considered a balanced isotonic solution?