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Flashcards in Heme Deck (35)
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1

What are some basic questions to ask patient in order to evaluate for potential blood disorders?

  • Have you ever had a blood problem such as anemia?
    • these pts w/ blood disorder – anemia/hemophelia etc, generally know. Its not a silent dx process. Have had enough bleeding episodes in past that they’ve been worked up, know if have sickle cell or thalasemmia etc so just ask them .
    • murmurs?
  • Have you ever had a problem with blood clotting or a serious bleeding problem?
  • Have you received a blood transfusion?-
    • need to ask most esp if signif med hx, if freq have tx, or had recent mass tx d/t trauma etc, need to be aware bc can dev abs, have potential for blood type to change, & finding compatible donor for them can be difficult so need to know b4 surgery
  • Do you use any medications such as aspirin or vitamins such as vitamin E or supplements such as ginseng, fish oil, gingko, or garlic known to affect blood clotting? How much? How often? When did you last use such?
    • Herbal “G’s”→ anticoag properties
  • Has a family member or blood relative ever had a serious bleeding problem? Many are hereditary
  • Have you ever had prolonged or unusual bleeding from cuts, nosebleeds, minor bruises, tooth extractions, or surgery?
    • Be careful how you ask..whats normal for me may not be normal for you etc. Ask “have you had any changes in bleeding or clothing” that is more indicative of a baseline prob than asking about “unusual” which may mean something different to a provider than a patient
  • Have you ever had excessive bleeding that required blood transfusion?
    • Just like in any disease process, a good H&P is key. More diagnostic or lab values don’t really tell you anything
    • If the results of these tests wont influence your anesthetic management, don’t order them
       

2

Goal of anemia assessment?

What are the transfusion requirements preop based on?

What to assess for in ROS?

  • Goal of assessment
    • determine etiology (ie renal/liver failure, underlying dx cause), duration, stability, related symptoms, and therapy (ie steroids, especially transfusions)
  • Ask about personal or family history of anemia.
  • Keep in mind the four transfusion requirements!           
    • Current Hgb/Hct
      • risk & ben of giving blood, coexisting dx that rely on blood delievery (CAD), how intense is the sx going to be & the est blood loss?
    • Rough estimate of hgb → asking patients fatigue level, exercise tolerance
  • Consider the type of surgical procedure, anticipated blood loss, and comorbid conditions that either affect oxygenation or can be affected by hypoxia (CAD)
  • May assess for:
    • Palpitations 
    • Fatigue
    • Chest pain
    • Melena
    • Bloody stools
    • Weight loss
    • Pallor
    • Murmurs (high CO heart failure)
    • Hepatosplenomegaly, lymphadenopathy
  • Trying to assess if theyd benefit from preop tx or should we have T&C/T&S etc

3

Preop Diagnostics for assessing heme system?

  • CBC- based on surgical considerations and H/P (anemic or high BL sx)
    • Women:
      • Hgb < 12 g/dL (normal 12-15.5 g/dL)
      • Hct < 36% (normal 37-47%)
        • < 11 g/dL in pregnant patients (increased plasma volume = physiologic anemia)
    • Men:
      • Hgb < 13 g/dL (normal 13.5-17.5 g/dL)
      • Hct < 40% (normal 42-52%)
    • Hematologist to determine cause and further evaluate newly diagnosed anemia or if severely anemic to get their insight
  • Blood type and screening; crossmatch- based on surgery and H/P
    • Type = what type they have. Screen = look for antibs on pts blood.
      • T&S go together.
  • Cross match = when ID donor blood & test it w/ your pts blood & look for a rxn
    • no rxn→ donor blood good to use for given amt of time usually 3-7 days, varies w/ hosp policy
    • Preoperative transfusion depending on degree of anemia, comorbidities, anticipated surgical blood loss, and risks vs benefits
  • Elective procedures may be postponed in patients with significant anemia until a cause and treatment can be addressed/optimize preop

4

Assessment for G6PD Deficiency?

  • Hemolytic anemia
  • Preoperative assessment should focus on:
    • (assess the severity→ mild vs severe)
      • Mild- few anesthetic considerations
      • Severe- robust anesth consids
    • previous episodes of hemolysis
    • identification of predisposing factors
    • determination of current hematocrit
      • see what drugs they are told to avoid, look at their allergy list
  • Current medications
    • Steroids
  • CBC

5

Sickle cell disease assesment?

  • Disease versus Trait (trait don’t go into crises, no anesth consids. Dx- need to start thinking about all those ischemic areas that may be damaged)
  • Preoperative assessment should focus on identification of organ dysfunction and acute exacerbations
    • Renal insufficiency-
      • are they on HD? Do they urinate a lot because they’ve lost the ability to concentrate urine?
    • Dehydration (loss of renal concentration ability)
    • Splenomegaly
    • Pulmonary hypertension/ pulmonary infarctions (pulmonary components)
      • do they use O2 at night or during the day?
    • Stroke- residual deficits?
    • Heart failure
    • Infections (greater risk due to splenic infarctions)*
    • Recent hospitalizations*
    • Advanced age*

* =high risk pt predictors of perioperative vasoocclusive complications

6

Diagnostics for sickle cell disease?

  • Oxygen saturation
    • will tell you about their pulmonary status, and if they have decreased perfusion to their extremities
  • CBC**- hematocrit
  • BUN, Creatinine → kidney insuff
  • ECG
  • Chest xray
  • Echocardiogram and abgs as indicated
    • Cardiac ischemia probs
  • Hematologist consult – impt to discuss if they should have tx preop if high risk hip sx, tx to get normal hgb up to higher lvl than sickled hgb, etc
  • Preoperative prophylactic transfusion is controversial- discussed in co-existing heme lecture
  • +/- invasive monitors
    • dep on degree of risk that pt has to degree of risk that sx has

7

Thalassemia considerations?

  • Preoperative considerations:
  • Potential for difficult airway secondary to maxillary deformities
    • frontal head and maxillary growth
  • Cardiac arrhythmias due to high CO heart failure
    • Echo, Ecg may be necessary
  • Coagulopathy
    • Regional?
    • Coags – if major sx
  • Monitoring
    • Routine
    • +/- invasive monitors with presence of heart failure or invasive sx
  • Check electrolytes
  • CBC

8

Considerations for aplastic anemia?

  • CBC!
    • WBC differential- help Infectious Disease (ID) determine what ABX needed for coverage
  • Coags!
    • these pts definitely need labs, want to look at their WBCs too
      • May need preop infusions of RBC/Platelets/Coags etc (usually will get them to be optimized b4 sx)
  • Baseline medications?
    • Steroids?
  • Airway hemorrhage possible with DVL
    • Preoperative airway plans? Dep on your comfort lvl & how good you are at DL vs glidescope etc
  • Type and crossmatch concerns
    • Increased difficulty with multiple transfusions. Need T&C early on
  • Reverse isolation
    • Prophylactic antibiotics based on CBC studies (degree of neutropenia)
    • Bypass preop, take from room to OR
  • Monitors
    • +/- invasive monitors (a. line); based on CBC and surgical risk
    • almost always invasive monitors will be necessary. Also if you don’t plan on taking them to ICU, you should be the one taking out their A line. Anticipate staying there for at least 20 minutes to hold pressure
  • Regional? Dep on coag status, plt lvls etc

9

Normal CBC? RBC? H/H? RBC indices? WBC? 

Nicole said this was "for our enjoyment" during lecture., I don't think we'll be tested on specific values...

  • RBC
    • 1.6-6.2 million/mm3  men
    • 4.2-5.4 million/mm3  women
  • Hct
    • 42-52% men
    • 37-47% women
  • Hgb
    • 13.5-17.5 g/dL men
    • 12-15.5 g/dL women
  • RBC indices (MCV, MCH, MCHC)
  • WBC
    • 5,000-10,000/mm3
  • Differential WBC –does help with surgical considerations

10

What is a trhomboelastography (TEG)?

  • Provides a “real time” visual representation of blood coagulation and fibrinolysis (clotting)
    • Used in Cardiac Rooms
    • Use if pt oozing and don’t know why
      • Takes 30 min to run
  • Can be assessed during surgery
  • Depicts characteristic abnormalities in clot formation and fibrinolysis
    • **Segment, problem area, and treatment *** know for exam

11

What are the various components of TEG?

  • R time
  • K time
  • Alpha angle
  • Maximum amplitude
  • Lysis at 30 min

12

What is the R segment? What does it monitor for? normal? problem wih? treatment?

  • R Segment: monitors coag factors (secondary hemostasis)
    • Does not tell you which factor has problem (1 through 13)
    • If prolonged → coagulation issue
      • TX: FFP
                      (general on bc don’t know issue)

From table:

  • Normal- 5-10 minutes
  • Definition- time to start forming clot
  • problem with coagulation factors (not sure which one)
  • Treamtent= FFP

13

What is k time? alpha angle?

  • K Segment/alpha angle: looks at fibrinogen, strengthing of clot (fibrin crosslink)
    • Ex: if R normal and K prolonged → Factor I issue!
      • TX: Cryo
        • (specific bc known issue)

From table:

K time

  • definition- time until clot reaches a fixed strenght
  • normal 1-3 minutes
  • porblem with fibrinogen
  • treatment cryoprecipitate

ALPHA angle

  • definition- speed of fibrin accumulation
  • normal value 53-72 degrees
  • problem with fibrinogen
  • treatment cryoprecipitate

14

What is maximum amplitude (ma?)

  • Maximum Amplitude (MA): clot strength → plts!
    • Plt plug determines how strong clot is
    • If diminished → don’t know if plt fx or # prob (send additional tests → CBC)

      Tx:

  • Low count: Plts
  • Dysfx: DDAVP or cryo (vWF)

from table:

  • definition= highest vertical amplitude of th teg
  • Normal- 50-70 min
  • problem with platelets
  • treatment- platelets and DDAVP!

15

What is lysis at 30 minutes?

  • LY30: also LY at 60 or 90 → breakdown of clot
    • If shows excessive breakdown of clot → Excess Fibrinolysis
      • Tx: Tranexemic Acid and/or Aminocaproic Acid (Anti-fibrolytics)

from table:

  • definition- percentage of amplitude reduction 30 minutes after maximum amplitude
  • normal 0-8%
  • problem with excess fibrinolysis
  • treament with TXA or Amicar

16

What does this TEG show?

Normal TEG

normal TEG – have good r & K times, AA approp, MA looks good, approp LY30. → you see a little bit of fibrinolysis (normal). We start to break down clots in about 30 minutes.

looks like brandy tumblie= do nothing

17

What does this TEG show?

Anticoagulants/hemophilia factor deficiency

R & K times prolonged. Alpha angle diminished. Angle dec. prob w/ anticoags- Maximum amplitude is diminished d/t dec in fibrin cross linking (probs from secondary hemostasis causes this problem downstream), tells us clot isn’t strong.  → Tx: FFP (don’t know what prob is). (looks like red wine glass)

18

What does this TEG mean?

PLT Blockers thrombocytopenia/thrombocytopathy

Normal R & angle, but max amplitude in isolation is severely dec. (maybe on anti-plt medications) tx: plt # → plts, plt fx: DDAVP/Cryo/vWF (looks like test tube!)

19

What does this TEG mean?

Fibrinolysis, presence of TPA

Classic ex of fibrinolysis – destroying a clot almost right away (excessive fibrinolysis. Maybe a pt that got TPA…  Tx: amicar or TXA. ​ (looks like upside down martini glass)

20

What does this TEG show?

Hypercoagulation

short R and K segment. Inc in angle & MA (rapid). Classic ex of hypercoagulation.  Treatment would be anticoagulants (intraop → heparin)

21

What does this TEG show?

DIC

  1. early stage of DIC when pt is hypercoaguable, using up all their coags and fibrinogen
  2. Second stage of DIC – Hypocoaguable; used up all of coagulations & now bleeding

22

Treatment for TEG if resembles brandy tumbler? red wine glass? test tube? champagne flute? upside down martini glass?

23

Coagulopathies assessment?

  • Determine diagnosis and the risk of bleeding ie mild vs severe

Inquire about

  • Known diagnosis (hemophilia, vWD, thrombocytopenia, polycythemia etc)
  • Coexisting conditions (renal/liver disease, malnutrition, cancer, recent drug exposure)
  • Current treatments- are they on steroids?
  • Current medications and herbals (ginseng, garlic, ginko biloba, fish oil)
  • Previous bleeding episodes
    • What kind of injury cause bleeding- is it just in tissues or joints after falling hard (severe hemophiliac) vs bleed for little longer but mild hemophiliac
  • Family history
  • Recent changes (vs whats normal) In bruising, length of bleeding with cuts etc
  • Petechiae
    • (very indicative of a coagulopathy problem)
    •  multiple bruises, hematomas, jaundice and frank bleeding

24

Diagnostic tests for coagulopathies?

  • Routine screening is not indicated, well-conducted history is more important
  • If H/P indicate bleeding disorder, or surgical risk of bleeding is high- additional laboratory testing is justified
    • Platelet count
    • CBC
    • PT/aPTT/INR
  • If specific cause of bleeding is known/suspected from coexisting dx process then follow with appropriate targeted testing
    • Liver enzymes, protein and albumin levels etc
  • Elective surgical procedures should be postponed if significant coagulopathy is present to determine cause and start treatment

 

25

Specific considerations for hemophilia a/b?

Hemophilia (A or B)

  • History of unexplained bleeding, spontaneous hemorrhage involving joints and deep muscles
  • Coagulation studies: anticipate prolonged aPTT, normal PT
  • Consult hematologist
    • Detailed plan for monitoring and replacement of factors

26

Specific considerations for von willebrand disease?

von Willebrand Disease (vWD)

  • History of easy bruising, mucosal bleeding v comm, epistaxis, menorrhagia, spontaneous hemorrhage (type III)
  • Coagulation studies: anticipate prolonged bleeding time, and aPTT, RPFA bc bleeding time not specific
    • Often factor VIII is low resulting in prolonged aPTT
  • Depending on type and severity consult hematologist (type 3 consult)

Desmopressin (in type 1 or 2), factor VIII or cryoprecipitate may be required preop

27

Specific considerations for thrombocytopenia?

  • Thrombocytopenia: platelets < 150,000/mm3
    • Try to determine cause and current treatment
      • Idiopathic thrombocytopenic purpura (ITP)
        • Steroids
  • Platelet count: only number, not function
    • > 100,000/mm3: neuroaxial anesthesia/major sx considered safe
    • < 50,000/mm3: increases surgical bleeding risk
      • Discuss with surgical team if want preop plts  (example neuro cases may require >100,000)
    • < 20,000/mm3 increases spontaneous bleeding risk
      • Transfuse
    • Each unit of Platelet transfusions generally increase count by 10,000/mm3 for every unit
  • Anemia, fever, infections, hypothermia, and antiplatelet drugs can increase bleeding at any platelet coun
    • my way of remembering- "hemorrhage is fucking awful (in) anesthesia"
      • ​h= hypothermia
      • i=infections
      • f= fever
      • a=anemia
      • a= antiplatelet

28

Polycythemia assessment considerations?

Polycythemia: hematocrit > 54% r/t viscosity; inc viscosity inc r/f clots

  • Increased risk for thrombosis and cardiac diseases (heart failure, MI)
    • any history of DVT or recent infarctions
  • Preoperative h/p should focus on pulmonary and cardiovascular systems
    • cyanosis, clubbing (decrease perfusion to extremities) wheezing, murmurs, exercise tolerance
      • Exercise tolerance: MOST IMPORTANT QUESTION
  • Diagnostic studies should include: pulse oximetry, ECG, CBC, abg and chest xray (if Hgb is excessive).
  • Consult hematology and postpone elective surgery
    • poss w/ pt phlebotomized outside of the hosp to optimize for sx

29

Which questions should you always ask any patient?

  1. Whats their exercise tolerance?
    1. Tells you everything you need to know about pulm, CV fx
  2. Any problems with anesthesia in the past?
    1. Genetic disorders → MH, acetylcholinesterase deficiency
  3. Allergies
    1. True allergy → anaphylaxis
  4. NPO status

30

Which patients have increased risk for thromboembolic disorders?

  • Certain patients are at higher risk for perioperative thromboembolisms
    • Hereditary hypercoagulable states (antithrombin III, protein C or S deficiencies)
    • Pregnancy, obesity
    • Cancer
    • Multiple episodes of past thromboembolisms
    • Atrial fibrillation
    • Mechanical heart valves
    • Inflamm assoc w/ sx can inc r/f blood clots on its own
  • Careful history focusing on prior thrombotic events, family history and concurrent drug therapies; random screening is not beneficial
    • Ask if they’ve had DVT/blood clots
      • How long ago/tx they had