Hematologic Flashcards
Anemia #s adult women
<11.5 hgb <36 hct
Anemia #s adult men
Hgb <12.5 hct <40
Ca02=
Arterial oxygen content. (Hgb x 1.39) sa02 + pa02 (.003)
Normal ca 02.
16-20
Compensatory mechanisms for anemia: 6
Dec blood viscosity, dec SVR, inc CO (inc SV AND hr), blood redist to areas w high extraction ratio, kidney secrete EPO, rightward shift of curve/ inc 2,3 DPG
What shifts curve right
Inc temp, inc 2,3 dpg, inc acidosis
What shifts curve left
Dec temp dec 2,3 dpg dalkalosis
Anesthesia management: anemia
Avoid decreasing CO (etomidate or high opioid induction), avoid left shift (avoid hyperventilation/alkalosis and hypothermia), maximize 02 delivery (inc fio2, prbcs)
What happens to VA in anemic pts
Less soluble= accelerated intake, but inc CO. Net effect is no OD
When CAD pt needs transfusion
Hgb <7 can lead to myo ischemia. Hct 28-30% may req transfusion if significant CAD esp w unstable coronary syndromes
When blood loss requires transfusion
15-30% loss= replace w crystalloid. >30% transfuse. >50% MTP:FFP:Plt 1/1/1.
ABL calculation
EBV x (pts hct- allowable hct) / pts hct
EBL in men and women
Men 75 ml/kg women 65
What 1 u PRBC does to hgb and hct
Hgb inc 1 g and hct 2-3%
Clinical signs w 20% ebv blood loss
Tachycardia, ortho hypo, CVP change
Signs w 40% acute blood loss
Tachycardia, hypotension, tachypnea, oliguria, acidosis, restless, diaphoresis, ecg ischemia, cvp change
What leads to hct decrease 1% every 24 hours
Hemolysis or acute blood loss
Acute blood loss induction and monitoring
Ketamine or etomidate. Invasive monitoring (CVP, a line), foley- UOP
Maintenance for acute blood loss
May be unable to tolerate VA. Scopolamine, benzos, opioids, keep warm.
Post op considerations in acute blood loss
Postop vent from fluid shifts during resuscitation, pulm edema, ARDS
What is MTP
> 10u PRBC in 24 hrs, replacing blood volume in 24 hrs, replacing >50% in 6 hrs
Consequences of MTP
Hypothermia, volume overload, dilutional coagulopathy (no clotting factors in PRBCs), decreased 2,3 dpg, hyperkalemia, citrate toxicity- binds to Ca, glucose-lactate-acidosis
Iron deficiency anemia hgb, ferritin
9-12, <30,
Vitamin b12 deficiency presentation
Hgb 8-10, large rbc volume, degeneration of spinal cord (paresthesia), thick, large tongue
Anesthesia management b12 deficiency
A/w eval and plan b, maintain adequate 02, avoid n20 (oxidizes b12), avoid regional if parasthesia
Anesthetic management for hereditary hemolytic anemia/spherocytosis
Avoid infections, CPB and mechanical valves may lead to accel hemolysis
Management of paroxysmal nocturnal hemoglobinura
High risk DVT. Avoid resp depressants, hypoxemia/perfusion, hypercarbia. Hydrate and dvt prophylaxis
G6PD management
Class V/VI little implication. Avoid oxidative drugs (nsaids/quinolone/sulfa), avoid depression of G6PD (iso/sevo/valium), avoid methylene blue (life threatening), avoid methomoglobinemia causing drugs (lido/prilocaine, silver nitrate), avoid oxidative stress (low temp, acidosis, low bg, infections).
Safe drugs for G6-D 5
Codeine, versed, propofol, fentanyl, ketamine
What pyruvate kinase deficiency does to curve/body
Shifts curve right, accum 2,3 dpg. Requires transfusion at birth. Jaundice.
Hemolytic anemia periop concerns
Inc risk hypoxia in tissues, inc infection risk if splenectomy, inc risk VTE, hgb <8 acute drop or chronic <6 need transfusion maybe, preop hydration. Caution methylene blue admin
Acute chest syndrome: happens in who, when, presentation
Sickle cell crisis 2-3 days postop. Pna like, pulm infiltrate in one segment, pulm vascular occlusion. Pleuritic CP, dyspnea, fever, pulm htn.
Acute chest syndrome: tx
Supplemental 02, inhaled NO to reduce pulm htn, abx, bronchodilators, pain management. Monitor for stroke, pain, and infection
Sickle cell disease RFs for periop complication
Old age, frequent sickling episodes, end organ damage (low baseline 02, elevated creat, cv dysfunc, stroke) and infection
Sickle cell disease. Operations that are low risk, moderate risk, and high risk
Low: extremity/minor procedures. Moderate: intraabdominal. High: IC, intrathoracic, hip replacement
Sickle cell disease: periop concerns, what you might do pre op w high risk sx, goal
End organ damage, cv dyfunc, infection. Transfuse to hct 30% pre op if high risk sx. Goal to dec hgb s w transfusion to <30%. Avoid hypoxemia, acidosis, hypovolemia, stasis
Sickle cell disease periop management
Supplemental 02, pre op hydration 12h, avoid resp depression, regional good for pain control but concern w stasis, aggressive pain management/tolerance, avoid tourniquets, keep warm, maintain high CO, prevent stasis while positioning
Thalassemia major complications that affect us
Hematopoiesis (maxillary and frontal bone overgrowth), splenomegaly/inc infec if removed, CHF/dyspnea/orthopnea, r side HF from jaundice, arrhythmia, sensitive to dig, SC compression
Anesthesia management thalassemia major: cardiac related
CHF common, arrhythmias, use cardiac sparing drugs
Thalassemia major anesthesia: blood risks
Coagulopathy, may not do regional. Thrombocytopenia from hypersplenism
Thalassemia major: complications from iron loading tx we worry about
DM (monitor bg), adrenal insufficiency (dec resp to pressors), coag abn/liver dysfunc, hypothyroid, ecg (arrhythmias), R HF (ECHO)
Methemoglobinemia: does what to curve and 02 delivery
Shifts left, little 02 delivered to tissues
Methemoglobinemia: % that causes complications
<30% none. 30-50% s/s of 02 deprivation. >50% coma and death
Agents that oxidize normal hgb and lead to methemoglobinemia 4
NO, nitrates, LA: prilocaine and benzocaine
What pulse ox does in methemoglobinemia pts
Typically reads 85%. Underestimates spo2 when sa02 >85 and over, overestimates it when its <85
Emergency tx of toxic methemoglobinemia
Avoid tissue hypoxia/left shift. 02. 1-2 mg/kg methylene blue 1% sol over 3-5 min, repeat in 30 min. A line for abg and levels. Correct acidosis. Monitor ekg for ischemia.
Aplastic anemia pre op needs
CBC/plt/wbc low. May need pre op transfusion, meds.
Drugs associated with marrow damage: 13
Abx, antidep, seizure meds, anti-inflam, anti-arrhythmics, antithyroidal, diuretics, bp meds, antimalarials, hypoglycemics, plt inhib, tranquilizers
Aplastic anemia anesthesia consid
Steroid stress dose if on roids, reverse isolation, prophylactic abx, hemorrhage (GI/IC), LV dysfunction from high output state, co-ex fanconi anemia (cleft palate and cv defects), difficulty cross matching blood after several transfusions
Aplastic anemia pre induction and induction considerations
Transfusions before induction. A/w hemorrhage possible w intub. Avoid nasal intub. Regional depends on clotting. Labile hemodynamic response to induction (avoid decreases in CO)
Aplastic anemia maintenance considerations
PEEP helps use less fio2 (avoid depressing BM), avoid NO, maintain normothermia
Aplastic anemia extub/postop consid
Period of greatest 02 demand, monitor coag status
4 hemostasis steps
Vascular spasm, primary hemostasis (plt plug), secondary hemostasis (coag and formation of fibrin), fibrinolysis
Plt adhere to exposed ___ in endothelium which also releases __ __ which activates ___ which then release __ and __. Leads to ___ and plt plug
Vwf, tissue factor, platelets, adp and txa2, aggregation
Secondary hemostasis=
Coagulation and fibrin formation
Secondary hemostasis factors. Which factor essential in all pathways
1-13 except for 6. Factor 4= calcium, essential in all
Extrinsic pathway: activated when, timing, factors, labs
Cascade initiated outside of IV space. Fast, 15 sec. 3 and 7. PT/INR
Intrinsic pathway: activated when, timing, factors, labs
Cascade inside of IV space, slow 6 mins, 8/9/11/12, PTT/ACT
Final common pathway factors
I, II, V, X, XIII
Fibrinolysis
Plasminogen via TPA converted to plasmin breaks down fibrin
How heparin works. Pathways, measurement of it.
Increases antithrombin 3 action, inhibits intrinsic pathway. Measured w ptt/act. Works on common pathways through inhibiting activated factor 10
How Coumadin works
Inhibits vit k factors (2,7,9,10), factor 7 extrinsic pathway, blocks this path. Measure pt/inr. Intrinsic, extrinsic, and final inhibited
What cryo contains
8, 13, vwf, fibrinogen
Hemophilia a. Deficiency, labs
Factor 8, ptt prolonged (intrinsic path) , normal pt
Hemophilia a: what happens pre op
Factor 8 infusion. 50 u/kg repeated q8-12 hrs to bring plasma levels near 100% before surgery. Ffp and cryo. Desmopressin 0.3 mcg/kg if mild heme a
Hemophilia b deficiency and labs
Factor 9. Prolonged ptt normal pt
Heme b anesthesia management. Use what for mild bleeding. Increased risk of what.
Recomb factor 9. 100 u/kg q12-24 hrs. Keep 9 >50% levels. Risk of thromboembolic complic since agents contain activated clotting factors. Ffp.
VWF disease. Types 1-3, when DDAVP works. What labs look like
1- quantitative, DDAVP works. 2- qualitative. 3- no vwf. Plt count normal. Bleeding time >10 min. May have prolonged ptt d/t low factor 8
VWF anesthesia management: avoid what, what you can give
Avoid nasal intubation. DDAVP for minor bleed (0.3 mg/kg in 50 ml nacl over 10-20 min to avoid tachycardia and hypotension). Intranasal 300 mcg DDAVP. Cryo if severe bleed. Ffp- just be careful of volume
Drug induced plt inhibition by what
Asa, nsaids, pcn/cephalosporin, dextran, hetastarch >2L
Pt factors that lead to plt dysfunction
Hypothermia <35c, acidosis <7.3, uremia, liver disease
Tx plt dysfunction
If mild-mod give desmopressin. Cryo for vwf. Plt transfusion
Dilutional thrombocytopenia tx
Ffp to restore pro coagulants, maybe platelets
What leads to marrow damage and failure of platelet production: 7
Radiation, chemo, chemical exposure, thiazides/etoh/estrogen, cancer, viral hepatitis, b12 deficiency
DIC lab levels
Plt <50l, prolonged PT/PTT, FSPs/D diners, low factor 8, decreased fibrinogen
DIC tx
Treat underlying disorder. Give plt, ffp, cryo, rbc if indicated. Give heparin to block thrombin formation which blocks further consumption of clotting factors
Vit k deficiency: lab levels and treatments
Prolonged PT, normal PTT. Vit K (if not emergent-takes 6-24h to work), FFP if active bleed
Plt ct normal
150-400 k
Bleeding time, what it assesses
3-10 min, plt func
PT: time, what it measures
10-12 sec, 2, 3, 5, 7, 10, fibrinogen
PTT: time, what it measures
25-35 sec, 2, 5, 7, 8, 9, 10, 11, 12. Fibrinogen.
ACT: time, what it measures
90-120 sec. 8, 9, 11, 12. Monitors heparin action.
Thrombin time, what it measures
9-11 sec, fibrinolysis. Prolonged w low fibrinogen
Fibrinogen time
160-350 sec
Hypercoagulability anesthesia consid
SQ heparin, compression stockings, ASA, vena cava filter, hydration. Regional unless on LMWH
What to do for Coumadin pt pre op. Emergent reversal
Hold for 5 days. Measure INR 1 day pre op. If >1.8 give 1 mg vitamin k sq. Emergent reversal give 7 ml/kg ffp
How to manage high risk w/o anticoag pt on warfarin
Start IV or SQ hep 3d after stopping warfarin. Turn heparin off 6h before surgery. If INR <1.5 can do surgery
Regional: what meds need to be stopped
LMWH (24 hrs), plavix (7d), sq heparin (2-4 hrs), Coumadin 7-10 days INR >1.5
