Flashcards in Surgery 2.2b - Sheet1 Deck (69):
What type of blood is used for emergecy situations?
Type "O" blood
If >4 U transfused, what is there increased risk of?
Autologous Transfusion: up to how many U?
Up to 5 U
1st U: How many days before?
4 days before
Last U: How many days before?
3 days before
Blood donors: Hgb > how many g/dL?
Hgb > 11 g/dL or if Hct > 34%
How long is the shelf life of banked whole blood?
42 days. Banked whole blood was once the gold standard
During storage: reduction of intracellular ADP and 2,3-diphosphoglycerate (2,3-DPG) does what?
Alters oxygen dissociation curve of haemoglobin --> decrease in oxygen transport!
What are Stored RBCs?
Acidotic with elevated levels of lactate, potassium, and ammonia
What is the product of choice for most clinical situations requiring resuscitation?
Red Blood Cells
What product is used for patients who are known to have been previously sensitized (but is not currently available for use in emergencies, as the thawing and preparation time is measured in hours)?
Frozen Red Blood Cells
How are leukocyte-reduced/washed red blood cells prepared?
Prepared by filtration that removes about 99.9% of the white blood cells and most of the platelets
What do leukocyte-reduced/washed red blood cells do?
Prevents almost all febrile, non-hemolytic reactions, allowing to HLA class I antigens, and platelet transfusion refractoriness and cytomegalovirus transmission
What is caused by massive blood loss and replacement with platelet-poor products (inadequate production)?
Platelet concentrates are used for what?
Qualitative platelet disorders
What is the shelf life of platelet concentrates?
120 hours from time of donation
How much is 1 unit of platelet concentrate?
Are platelet concentrates capable of transmitting infectious diseases?
Yes, and they account for allergic reactions
What is the therapeutic level?
50,000 to 100,000/uL
What are platelet concentrates for?
Chronic anemias, bone marrow, liver failure; Pre-op and post-op surgery; CHF, uremia
What is the usual source of vitamin K-dependent factors?
Fresh Frozen Plasma
Fresh frozen plasma is the only source of which factor?
Only source of factor V
What is the shelf life of fresh frozen plasma?
up to 5 days
What is fresh frozen plasma for?
Liver disease, warfarin overdose; DIC, TTP, [down arrow]CF d/t large volume transfusions
Name the indications for blood transfusions
Improvement in oxygen-carrying capacity; Treatment anemia; Volume replacement
The treatment of anemia
Hgb approaching 9 g/dL
Blood loss can be evaluated by estimation in wound, drapes, sponges, suctioned
Describe the study that verified this
A prospective randomized controlled trial in critically ill patients that compared a restrictive transfusion threshold to a more liberal strategy
What did the study demonstrate?
It demonstrated that maintaining hemoglobin levels between 7 and 9 g/dL had no adverse effect on mortality. In fact, patients with APACHE II scores of <20 or patients age <55 years actually had a lower mortality.
Loss of <20% blood -->
Loss of >20% blood -->
Additional packed RBC
Massive transfusion -->
Addition of fresh frozen plasma
What is the rationale for new concepts in resuscitation?
In civilian trauma systems, nearly half of all deaths happen before a patient reaches the hospital, and many are nonpreventable. Patients who survive to an emergency center have a high incidence of truncal hemorrhage, and deaths in this group of patients may be potentially preventable.
Truncal hemorrhage patients in shock often present with what?
The early coagulopathy of trauma in the emergency department. They are at significant risk of dying.
What are the three basic components of damage control resuscitation?
Red Blood Cells; Plasma; Platelets
In Iraq and Afghanistan, what was the variation of plasma:platelet: red blood cell ratios?
They varied from 1:1:1 to 0.3:0.1:1, with corresponding survival rates ranging from 71% to 41%
A recent prospective observational study evaluating current transfusion practice at 10 Level 1 centers documented what?
The wide variability in practice and improved outcomes with earlier use of increased ratios of plasma and platelets
79 patients receiving ratios less than 1:2 were how many times more likely to die than patients with ratios of 1:1 or higher?
What are febrile nonhemolytic reactions?
Increase in temp >1degree C associated with a transfusion (1% of transfusions)
What are some bacterial contaminations of infused blood?
Yersinia enterocolitica, Pseudomonas
What to do in the case of bacterial contamination of infused blood?
Emergency! Discontinue transfusion ASAP; Oxygen, adrenergic blocking agents, antibiotics
What percentage of transfusions result in allergic reactions?
What are the symptoms of an allergic reaction during transfusion?
Mild rash, urticaria and fever within 60-90 minutes of the start of transfusion
What is the treatment for mild allergic reaction?
What is the treatment for severe allergic reaction?
Steroids or epinephrine
What are respiratory complications associated with?
Transfusion-associated circulatory overload
When do respiratory complications occur?
Occur with rapid infusion of blood, plasma expanders, crystalloids especially in older patients with heart disease
What are the symptoms of respiratory complications?
Rise in venous pressure, dyspnea, cough, rales in LLF
What is a transfusion-related acute lung injury (TRALI)?
Noncardiogenic pumonary edema related to transfusion
When can a TRALI occur?
Occurs with administration of any plasma-containing blood product
What are the symptoms of TRALI?
Fever, rigors, bilateral pulmonary infiltrates on CXR
When can TRALI occur?
Within 1-2 hours after onset of transfusion (before 6 hours)
What is the cause of acute hemolytic?
Administration of ABO-incompatible blood
In what percentage of cases is acute hemolytic fatal?
What commonly leads to the administration of ABO-incompatible blood?
Technical or clerical errors
What are the symptoms of immediate hemolytic?
Intravascular destruction of RBCs and consequent hemoglobinemia and hemoglobinuria; acute renal insufficiency d/t toxicity associated with free Hgb in the plasma; tubular necrosis and precipitation of Hgb in tubules
When could delayed hemolytic reaction occur?
Occur 7-20 days after transfusion
What are the symptoms of a delayed hemolytic reaction?
Extravascular hemolysis, mild anemia, indirect hyperbilirubinemia; low antibody titer at time of transfusion but titer increases after transfusion; anamnestic response
What diseases can be transmitted through transfusion?
Malaria (P. malariae), Chagas' disease, Brucellosis, Syphilis, CMV infection
What to look for in careful review of the patient's history?
Abnormal bleeding/bruising, drug use
A platelet count > 1 M / uL could lead to what?
Bleeding or thrombotic complications
A platelet count < 100 T / uL will require what?
Major surgical procedures
A platelet count < 50 T / uL will require what?
Minor surgical procedures
A platelet count < 20 T/ uL will result in what?
For: Vit K def; warfarin therapy...VII...X, V, II (prothrombin), Fibrinogen
For: heparin therapy...XII...HMWK...Prekallikrein...XI...IX...VIII...X, V, II (prothrombin), Fibrinogen
Measured PT divided by Control PT...N:2-3