MAC Fluid Management & Blood Products 1 — Questions and Answers
Question 1: Which crystalloid solution is most appropriate for resuscitation in a patient at risk for hyperchloremic metabolic acidosis?
- Normal saline (0.9% NaCl)
- Lactated Ringer's solution (Correct answer)
- 3% hypertonic saline
- 5% dextrose in water
Correct answer: Lactated Ringer's solution
Lactated Ringer's is a balanced crystalloid with a chloride concentration closer to physiologic plasma levels, making it preferable to normal saline, which can cause hyperchloremic acidosis with large volumes.
Question 2: According to current evidence-based guidelines, what is the hemoglobin transfusion threshold for a hemodynamically stable, non-cardiac ICU patient without active ischemia?
- Hgb < 10 g/dL
- Hgb < 9 g/dL
- Hgb < 8 g/dL
- Hgb < 7 g/dL (Correct answer)
Correct answer: Hgb < 7 g/dL
The TRICC trial and subsequent guidelines support a restrictive transfusion threshold of Hgb < 7 g/dL in stable non-cardiac ICU patients, as it does not worsen outcomes and reduces transfusion-related risks.
Question 3: Which dynamic parameter BEST predicts fluid responsiveness in a mechanically ventilated patient with regular cardiac rhythm?
- Central venous pressure (CVP)
- Pulse pressure variation (PPV) (Correct answer)
- Static pulmonary artery occlusion pressure
- Urine output over 30 minutes
Correct answer: Pulse pressure variation (PPV)
Pulse pressure variation > 13% in mechanically ventilated patients with regular rhythm reliably predicts volume responsiveness, unlike static preload markers such as CVP or PAOP.
Question 4: In a massive transfusion protocol (MTP) for hemorrhagic shock, what is the currently recommended ratio of packed red blood cells (pRBCs) to fresh frozen plasma (FFP) to platelets?
- 4:1:1
- 1:1:1 (Correct answer)
- 3:2:1
- 6:4:1
Correct answer: 1:1:1
The PROPPR trial established that a balanced 1:1:1 ratio of pRBCs:FFP:platelets mimics whole blood, reduces dilutional coagulopathy, and improves 24-hour survival in massive hemorrhage.
Question 5: A patient develops acute hypoxemic respiratory failure with bilateral pulmonary infiltrates and PaO2/FiO2 ratio < 300 within 6 hours of transfusion, with no evidence of volume overload. This presentation is most consistent with:
- Acute hemolytic transfusion reaction
- Febrile non-hemolytic transfusion reaction
- Transfusion-associated circulatory overload (TACO)
- Transfusion-related acute lung injury (TRALI) (Correct answer)
Correct answer: Transfusion-related acute lung injury (TRALI)
TRALI is defined as new acute lung injury within 6 hours of transfusion with PaO2/FiO2 < 300 and bilateral infiltrates in the absence of circulatory overload, distinguishing it from TACO.
Question 6: Which colloid solution has been shown in multiple randomized controlled trials to significantly increase the risk of acute kidney injury and renal replacement therapy in critically ill patients?
- 5% albumin
- Dextran 40
- Hydroxyethyl starch (HES) (Correct answer)
- Gelatin-based colloids
Correct answer: Hydroxyethyl starch (HES)
The CHEST and 6S trials demonstrated that hydroxyethyl starch solutions significantly increase rates of acute kidney injury and need for renal replacement therapy in critically ill patients, leading to FDA safety warnings.
Question 7: Cryoprecipitate is the most concentrated source of which clotting factors and proteins?
- Factors II, VII, IX, and X
- Factor VII and protein C
- Antithrombin III and protein S
- Fibrinogen, Factor VIII, von Willebrand factor, and Factor XIII (Correct answer)
Correct answer: Fibrinogen, Factor VIII, von Willebrand factor, and Factor XIII
Cryoprecipitate is the cold-precipitate fraction of FFP that contains concentrated fibrinogen, Factor VIII, von Willebrand factor, and Factor XIII, making it the treatment of choice for hypofibrinogenemia in bleeding patients.
MAC Fluid Management & Blood Products 1
Which crystalloid solution is most appropriate for resuscitation in a patient at risk for hyperchloremic metabolic acidosis?