Blood disorders Flashcards
What are some basic questions you can ask about the hematologic system?
- Have you ever had a blood problem like anemia?
- Have you ever had a blood clot or serious bleeding?
- Have you received a blood transfusion?
- Do you take any meds (ASA, Vit E, ginsent, garlic…)that might affect blood clotting
- Any family with bleeding problems?
The goall of assessment in an anemic patient is to determine:
(5)
- Goal to determine:
- etiology
- duration
- stability
- related symptoms
- therapy (especially transfusions)
What do you need to consider regarding the surgical procedure for an anemic patient?
- type of surgery
- anticipated blood loss
- comorbid condisions that can affect oxygenation or be affected by hypoxia
What physical findings should you assess for in an anemic patient?
(10)
- palpitations
- fatigue
- chest pain
- Melena
- bloody stools
- weight loss
- pallor
- murmors
- hepatosplenomegaly
- lymphadenopathy
What diagnostics can you use to determine anemia?
normal values?
- CBC
- women hgb <12 g/dL (nml 12-15.5); HCT < 36%
- men hgb <13 g/dL (nml 13.5-17.5); HCT <40%
- Blood type and screening or crossmatch
- consider pre-op tx depending on degree of anemia, comorbidities, EBL, and risk vs benefits
- Consider postponing elective procedures
What should pre-op assessment of Glucose-6-phosphate dehydrogenase deficiency focus on?
- G6PD is a type of hemolytic anemia
- Focus on:
- previous episodes of hemolysis
- identification of predisposing factors
- drugs to avoid
- determine current HCT
- Current medications- may be on steroids
- CBC
What should you assess in a pt with sickle cell disease?
- Assess if it is disease or trait
- Focus on identifying organ dysfunction and acute exacerbations. bolded are high risk of vasoocclusive complications
- renal insufficiency
- dehydration (loss of renal concentation ability)
- splenomegaly
- pulm HTN/pulm infarction
- stroke
- heart failure
- infection- greater risk with splenic infarctions
- recent hospitalizations
- advanced age
How can you diagnose the extent of disease for a pt with sickle cell disease?
- Oxygen saturation- indicates pulm status and extremity perfusion
- CBC- Hct
- BYN/Cr
- ECG
- CXR
- ECHO
- ABG
- hematologist consult
- may want invasive monitors during procedure
What are some pre-op considerations for Thalassemia?
- Potential for difficult airway secondary to maxillary deformities
- Cardiac arrhythmias due to heart failure
- ECHO, ECG
- Coagulopathy
- regional?
- Check coags
- Monitoring
- routine
- may want invasive if pt has Heart failure
- Check lytes and CBC
What are some preoperative considerations for a patient with Aplastic anemia?
- CBC and Coags!
- may need pre-op infusions of RBC/Platelets/Coags, etc
- baseline medications
- steroids?
- Airway hemorrhage possible with DVL
- Type and crossmatch concerns- allow time for blood bank to get blood prepared
- Reverse isolation
- prophylactic abx based on CBC studies and degree of neutropenia
- monitors
- maybe invasive depending on CBC and surgical risk
- Regional?
What are the normal values for a CBC?
RBC
Hct
Hgb
WBC
- RBC
- 1.6-6.2 million/mm3 for men
- 4.2-5.4 million/mm for women
- Hct
- 42-52% for men
- 37-47% for women
- Hgb
- 13.5-17.5 g/dL men
- 12-15.5 g/dL women
- WBC
- 5,000-10,000/mm3
What is a TEG?
- Provides a “real time” visual representation of blood coagulation and fibrinolysis
- Can be assessed during surgery
- Depicts characteristic abnormalities in clot formation and fibrinolysis
- helps figure out what the problem area is
- Used in cardiac cases or if pt is oozing a lot
What do the different components of the TEG represent?
problem
treatment
What should you find out about a patient with coagulopathies?
- determine the diagnosis and the risk of bleeding
- inquire about:
- known diagnosis
- hemophilia, vWD, thrombodytopenia
- co-existing conditions
- liver disease, malnutrition, cancer, recent drugs exposure
- current treatments
- medications and herbals
- previous bleeding episodes
- family history
- recent changes in bruising, length of bleeding with cuts, etc
- petechiae, bruises, frank bleeding
- known diagnosis
What can you use do diagnose coagulopathies?
- Routine screening not indicated, thorough history
- If H/P indicates bleeding disorder and surgical risk of bleeding is high, testing is justified
- Platelet count
- CBC
- PT/aPTT/INR
- More targeted testing if you have specific suspicion
- liver enzymes, protein and albumin levles
- Elective surgeries should be posponed if significant coagulopathy is present
What coagulation studies would you expect to be off for a patient with Hemophilia?
- prolonged aPTT and normal PT
- history of unexplained bleeding
- consult hematologist to form plan for monitoring and replacing factors
What symptoms and lab abnormalities would you expect to see with vWD?
what might these pts require pre-operatively?
- History of easy bruising, epistaxis, menorhagia, spontaneous hemorrhage
- coag studies, anticipate:
- prolonged bleeding time, aPTT, RPFA
- often factor 8 is low, resulting in prolonged aPTT
- depending on type and severity, consult hematologist
- May require pre-op
- desmopressin
- factor VII
- cryo
What is considered thrombocytopenia?
how many platelets must pt have for neuroaxial anesthesia?
when is there increased surgical bleeding risk?
when is there risk for spontaneous bleed?
how much do plt transfusions usually increase count?
- Thrombocytopenia <150,000/mm3
- neuroaxial >100,000
- increased surgical bleed risk <50,000
- risk of spontaneous bleed <20,000
- transfusion increases count by 10,000
What is considered polycythemia?
- HCT >54%
- increased risk for thrombosis and cardiac disease (HF, MI)
- pre-op h/p should focus on cardiopulmonary system
- diagnostic studies should include: pulse ox, EKG, CBC, ABG, and Xray
- consult hematolgoy and postpone elective surgery
What patients are at higher risk for perioperative thromboembolisms?
- Hereditary hypercoagulable states (antithrombin III, protein C or S deficiencies)
- pregnancy, obesity
- cancer
- hx of thromboembolisms
- Afib
- mechanical heart valves
- **postpone elective surgery if current recent clot
What is the risk of recurrent DVT within 3 months
without anticoagulation
1 month of warfarin
3 months of warfarin?
- without anticoagulation, risk is 50%
- 1 month of warfarin reduces risk to 10%
- 3 months of warfarin reduces risk to 5%
Which procedures do not require interruption of Coumadin therapy?
- dental
- endoscopic
- cataract
- superficial operations
When should coumadin be held preoperatively?
- hold 4-5 days prior to surgery
- monitor INR and PT
- INR <1.5 considered safe for surgical procedures and neuraxial blockade
- consult hematologist, cardiologist, or treating physician concerning need for bridging treatment with heparin
- heparin is usually started 3 days after coumadin is stopped
- Reversal with vit K, 4 factor PCCS, or FFP
When should you stop heparin therapy before surgery?
- 6 hours prior
- 6-8 hours for neuraxial block placement
- wait at least 1 hour after block to give/restart heparin
- Monitor aPTT/ACT
- may reverse with protamine if required
When does LMWH need to be stopped before surgery?
therapeutic LMWH
prophylactic
after neuraxial block?
emergent reversal?
- therapeutic- hold for 24 hours before
- prophylactic- hold for 12 hours before
- must wait >2 hours after neuraxial block
- protamine is a partially effective reversal
When is ASA stopped before surgery?
- traditionally 7-10 days preop
- typically 3-4 days
- always evaluate risk of bleeding vs risk of clot
- Withdrawing ASA will put pt in hypercoagulable state which is associated with 3x increase in the risk of major cardiac events
