Resident Readiness General Surgery by Debra Klamen, Brian George, Alden Harken, Debra Darosa
Ads: Link
RUQ. He has an Hgb of 12 but is lethargic, cold, clammy, and tachycardic. When should you transfuse him?
A. When the Hgb is <9, per the GDT trial
B. When the Hgb is <7, per the TRICC trial
C. Now
D. 10 minutes ago
3. What is the most appropriate order for a patient who is scheduled to undergo a coronary artery bypass graft in 10 days?
A. Type and screen only
B. Type and cross 2 U
C. Type and cross 10 U
D. None of the above
Answers
1. B . This is a euvolemic patient in the ICU with no evidence of bleeding. The TRICC trial applies. Hold off on transfusion.
2. D . You are already behind because the patient is in shock. The patient has probably already lost at least 30% of the blood volume, regardless of the Hgb.
3. D . This patient will need to be typed and crossed for blood given the high likelihood of bleeding, but not until closer to the operation. The blood bank will not reserve the blood for this patient for 10 days.
SUGGESTED READINGS
Hébert PC, Wells G, Blajchman MA, et al. A multicenter, randomized, controlled clinical trial of transfusion requirements in critical care. NEngl J Med . 1999;340(6):409–417.
Rivers E, Nguyen B, Havstad S, et al. Early goal-directed therapy in the treatment of severe sepsis and septic shock. N Engl J Med . 2001;345(19):1368–1377.
A 70-year-old Man With “Bad Blood”
Emily Miraflor, MD, Louise Y. Yeung, MD, Brian C. George, MD, and Alden H. Harken, MD
Ephraim Hatfield IV is a 70-year-old male from Tug Fork, West Virginia, whose chief complaint is “bad blood.” One week ago the patient recounts an attempt on his life where “I left a bunch of blood on the pavement.” At your hospital, he received multiple blood transfusions. Following discharge, the patient noted that “my eyes turned yellow and my urine turned brown.” The patient believes that he received “bad blood”—perhaps even from a McCoy donor.
1. Explain the primary reason to transfuse blood.
2. Name an alloantigen that, when present in donor blood, can precipitate a transfusion reaction.
3. Did the patient in the vignette above have an acute or delayed reaction?
TRANSFUSION REACTIONS
Answers
1. The only reason to transfuse blood is to increase oxygen-carrying capacity via hemoglobin. So, what we’d really like to do is transfuse pure hemoglobin. That has been tried. The 64,000 molecular weight hemoglobin tetramer breaks up to provoke an osmotic diuresis that rapidly abbreviates the therapeutic effect. So, we transfuse hemoglobin encapsulated in red cells.
One unit of packed red blood cells can be expected to increase a patient’s hemoglobin by approximately 1 g/dL, or the hematocrit by approximately 3%.
2. Unfortunately, 1 U of transfused blood contains a whole lot more than hemoglobin—and most of this stuff, you don’t want. The stuff you don’t want comes in 2 categories:
A. The stuff the donor was born with
B. The stuff the donor acquired
A. Born with : Red blood cells come in multiple flavors. We focus on the A and B red cell antigens, but a short list of additional proteins includes C, D, E, c, e, K, k, JK a , JK b , s, Fy a , Fy b , and M. Therefore, every unit of transfused blood is at least a little mismatched.
B. Acquired : What you do not want to do, when you receive a blood transfusion, is to dwell on the possible escapades of donors during the weeks before they offered up their blood. Perhaps the donor was a Mr. Rogers or a Mother Teresa who spent his or her life in church or school, but more likely, the donorenjoyed a more stimulating life. Now, in the absence of a Facebook page on the social antics of your blood donor, you—the blood recipient—are at the mercy of the blood bank laboratory technicians. Fortunately, the people who work in transfusion laboratories do not go to wild parties; their idea of excitement is to identify an arcane antibody in a crossmatch. These protectors of the faith can recite alloantibodies as effortlessly as their church catechisms.
The usual suspects are:
1.
A. When the Hgb is <9, per the GDT trial
B. When the Hgb is <7, per the TRICC trial
C. Now
D. 10 minutes ago
3. What is the most appropriate order for a patient who is scheduled to undergo a coronary artery bypass graft in 10 days?
A. Type and screen only
B. Type and cross 2 U
C. Type and cross 10 U
D. None of the above
Answers
1. B . This is a euvolemic patient in the ICU with no evidence of bleeding. The TRICC trial applies. Hold off on transfusion.
2. D . You are already behind because the patient is in shock. The patient has probably already lost at least 30% of the blood volume, regardless of the Hgb.
3. D . This patient will need to be typed and crossed for blood given the high likelihood of bleeding, but not until closer to the operation. The blood bank will not reserve the blood for this patient for 10 days.
SUGGESTED READINGS
Hébert PC, Wells G, Blajchman MA, et al. A multicenter, randomized, controlled clinical trial of transfusion requirements in critical care. NEngl J Med . 1999;340(6):409–417.
Rivers E, Nguyen B, Havstad S, et al. Early goal-directed therapy in the treatment of severe sepsis and septic shock. N Engl J Med . 2001;345(19):1368–1377.
A 70-year-old Man With “Bad Blood”
Emily Miraflor, MD, Louise Y. Yeung, MD, Brian C. George, MD, and Alden H. Harken, MD
Ephraim Hatfield IV is a 70-year-old male from Tug Fork, West Virginia, whose chief complaint is “bad blood.” One week ago the patient recounts an attempt on his life where “I left a bunch of blood on the pavement.” At your hospital, he received multiple blood transfusions. Following discharge, the patient noted that “my eyes turned yellow and my urine turned brown.” The patient believes that he received “bad blood”—perhaps even from a McCoy donor.
1. Explain the primary reason to transfuse blood.
2. Name an alloantigen that, when present in donor blood, can precipitate a transfusion reaction.
3. Did the patient in the vignette above have an acute or delayed reaction?
TRANSFUSION REACTIONS
Answers
1. The only reason to transfuse blood is to increase oxygen-carrying capacity via hemoglobin. So, what we’d really like to do is transfuse pure hemoglobin. That has been tried. The 64,000 molecular weight hemoglobin tetramer breaks up to provoke an osmotic diuresis that rapidly abbreviates the therapeutic effect. So, we transfuse hemoglobin encapsulated in red cells.
One unit of packed red blood cells can be expected to increase a patient’s hemoglobin by approximately 1 g/dL, or the hematocrit by approximately 3%.
2. Unfortunately, 1 U of transfused blood contains a whole lot more than hemoglobin—and most of this stuff, you don’t want. The stuff you don’t want comes in 2 categories:
A. The stuff the donor was born with
B. The stuff the donor acquired
A. Born with : Red blood cells come in multiple flavors. We focus on the A and B red cell antigens, but a short list of additional proteins includes C, D, E, c, e, K, k, JK a , JK b , s, Fy a , Fy b , and M. Therefore, every unit of transfused blood is at least a little mismatched.
B. Acquired : What you do not want to do, when you receive a blood transfusion, is to dwell on the possible escapades of donors during the weeks before they offered up their blood. Perhaps the donor was a Mr. Rogers or a Mother Teresa who spent his or her life in church or school, but more likely, the donorenjoyed a more stimulating life. Now, in the absence of a Facebook page on the social antics of your blood donor, you—the blood recipient—are at the mercy of the blood bank laboratory technicians. Fortunately, the people who work in transfusion laboratories do not go to wild parties; their idea of excitement is to identify an arcane antibody in a crossmatch. These protectors of the faith can recite alloantibodies as effortlessly as their church catechisms.
The usual suspects are:
1.
Similar Books
