Blood Component Therapy Quiz: Indications for Transfusion

58 Questions

What is the basic philosophy behind blood component therapy?

Providing patients with the specific fraction of blood they lack

Why is lactated Ringer solution not recommended as a diluent or carrier for PRBCs?

Because it contains Ca2+ which can cause clotting

What is the approximate Hct value of PRBCs?

60%

How does using hypotonic solutions as diluents affect RBCs?

RBCs will swell and eventually burst

Which component of blood is conserved by using PRBCs rather than whole blood?

Plasma

What is the purpose of utilizing crystalloid or colloid as a carrier for PRBCs?

To facilitate the administration of PRBCs

What is the recommended solution compatible with packed erythrocytes that has a pH of 7.4?

Normosol-R with

What is the primary reason for administering RBC transfusions?

To increase O2-carrying capacity

Why is increasing intravascular volume alone not an indication for blood transfusion?

It can be achieved through crystalloid administration

What should prompt transfusion therapy besides the patient's Hb value?

Overall patient status

What does the Hb value primarily serve as in defining transfusion strategies?

Primary criterion

What can be created by using crystalloids or colloids to treat hypovolemia?

Normovolemic dilutional anemia

At what Hb level did inadequate splanchnic and preportal oxygen delivery and consumption occur in a study by Mathru and colleagues?

$5.9$ g/dL

In which patients did a 1988 NIH Consensus Conference conclude that perioperative blood transfusions are rarely needed?

Patients with Hb value over $10$ g/dL

What is a key consideration for determining when a patient should benefit from a blood transfusion?

**No specific measure **

What does the O2 extraction ratio require for prediction of benefits from blood transfusions?

Invasive monitoring

patients with chronic anemia (as in renal failure) might tolerate an Hb concentration of

less than 6 to 7 g/dL

What is the recommended solution compatible with packed erythrocytes ?

5% dextrose in 0.45% saline

What is the recommended solution compatible with packed erythrocytes ?

5% dextrose in 0.9% saline

why 5% Dextrose in 0.2% saline is not recommended solution compatible with packed erythrocytes ?

cause hemolysis at 37 temperature

which solution cause the most hemolysis at 37 temperature

5% Dextrose in water

American College of Surgeons Classes of Acute Hemorrhage- class I defined by

Blood loss-750mL,

Metabolic Characteristics of Packed Red Blood Cells, what is the pH value ?

6.79

Metabolic Characteristics of Packed Red Blood Cells, what is the pCO2 value ?

What approach is typically used to measure blood loss when assessing the need for blood transfusions?

Combination of visualization and gravimetric measurements

In what way did anesthesiologists tend to misjudge blood loss according to a study in patients undergoing spine surgery?

Overestimated by as much as 40%

Why did optical scanners tend to underestimate blood loss compared to standard gravimetric calculations?

Due to variations in measurement accuracy

What is a key consideration needed to determine whether subsequent units of blood are necessary after the initial transfusion?

Measurement of vital signs and blood loss

Why is there no universally accepted standard for quantifying blood loss?

Variability in measurement accuracy

What is an important component related to intraoperative transfusion medicine?

Predicting surgical blood loss

What is a limitation of intermittent measurements of Hb levels during blood loss?

Fluid shifts and intravenous volume infusions

How does the accuracy of SpHb (spectrophotometric finger technology) relate to patients with moderately to severely low Hb levels?

It decreases

Which factor can help assess the accuracy of the SpHb value provided by the monitor?

Perfusion index (PI) greater than 4% to 5%

How does a bupivacaine digital nerve block impact the accuracy of SpHb values?

Decreases inaccurate values

What is an important feature that can improve the accuracy of SpHb measurements?

Perfusion index (PI) greater than 4% to 5%

In what situation would SpHb monitoring perform worse according to the text?

Patients with moderately to severely low Hb levels

What is the recommended method for clinicians to detect a changing Hb level ?

Observation of the trend

According to Giraud and colleagues, what was the main advantage of SpHb monitoring?

Less invasiveness but continuous data provision

What factor should prompt clinicians to explore the reasons behind sudden changes in SpHb value, even if the absolute value is satisfactory?

Decrease in SpHb reading from 11 g/dL to 9.5 g/dL

Which point-of-care Hb test is mentioned as providing quick and efficient bedside Hb level determination in less than 5 minutes?

HemoCue

What is the primary advantage of using warming of the finger in terms of SpHb monitoring accuracy?

Improve PI and thereby SpHb accuracy

Preoperative anemia (i.e., low Hb value in women <12 g/ dL; in men <13 g/dL) is a common comorbidity among patients undergoing major surgery with an incidence of

40%

Preoperative anemia is an independent risk factor that can increase

postoperative acute kidney injury

when the Hb value should be obtained In patients with a moderate to high risk of significant blood loss (defined as >500 mL)

3 to 8 weeks prior to surgery

what is the goal of treating anemia preoperatively

decrease the need for intraoperative transfusions

Erythropoiesis-stimulating agents (ESAs)

Stimulate BM

What Hb value range is considered for a restrictive transfusion strategy?

7-8 g/dL

In a liberal transfusion strategy, at what Hb value is blood transfusion typically administered?

9-10 g/dL

What did Ely and Bernard confirm regarding transfusion triggers?

better outcomes have not consistently occurred

What is a potential advantage of using a restrictive transfusion strategy?

Fewer transfusion reactions

What conclusion arises from studies comparing liberal and restrictive transfusion strategies?

No consistent benefit to liberal strategy

What is the primary concern highlighted with a one-value transfusion strategy?

The lack of consideration for patient comorbidities

Why might a one-size-fits-all approach to transfusion decision-making be insufficient?

It lacks specific indications for subsequent blood units

What does the American College of Surgeons propose as a basis for transfusion decisions?

overall condition of the patient

What is the main limitation highlighted in the liberal versus restrictive strategy associated with Patient Blood Management (PBM)?

Failure to address indications for repeat transfusions

What is one of the important conclusions made about Hb levels and transfusion decisions?

Variability exists in the need for increased O2-carrying capacity

What is a caution highlighted regarding using Hb levels for transfusion decisions?

Patients may have different requirements for O2 delivery

ASA’s 2015 updated practice guidelines recommendations?

Transfusion is almost always indicated when it is less than 6 g/dL

Study Notes

Blood Transfusions

Recommended solutions compatible with packed erythrocytes: 5% dextrose in 0.45% saline, 5% dextrose in 0.9% saline, 0.9% saline, and Normosol-R with a pH of 7.4.
RBC transfusions are given to increase O2-carrying capacity, not to increase intravascular volume.

Indications for Transfusion

A sole Hb value should not be the only basis for a transfusion decision.
Consider the overall status of the patient, including hemodynamics, organ perfusion, and oxygen delivery.
Goals for transfusion in hemorrhaging patients: restore and maintain intravascular volume, cardiac output, and organ perfusion.

Hemoglobin Values

1988 National Institutes of Health (NIH) Consensus Conference: healthy patients with Hb > 10 g/dL rarely require perioperative blood transfusions, while patients with acute anemia with Hb < 7 g/dL frequently require blood transfusions.
Patients with chronic anemia (e.g., renal failure) may tolerate Hb < 6 to 7 g/dL.