GI/Liver Flashcards
Post op jaundice causes
Prehepatic: hematoma abs, hemolytic transfusion rxn (increased indirect unconjugated bili-delayed or acute
Hepatic:
- Chonic dz (viral hepatitis)
- Ischemic or hypoxic injury/sepsis (would see abnl LFT’s/coags/plts indicating liver dysfunction)
- Drug induced (can detect this from reviewing records for drugs such as a-methyldopa, Tylenol, chloramphenicol, isoniazid, sulfonamides, and of course r/o halothane for anes record.)
- Inborn errors of metabolism (gilberts-unconjugated hyperbillirubemia), crigler Najjar (decreased or absent gluonyl transferase, unconjugated hyerbili), n dubin johnson-conjugated hyperbil
- Intrahepatic cholestasis
post hepatic
Cholecystitis, Common Bile duct stone, Pancreatitis (would see conjugated hyperbiirubinemia)
Etio of hemodyamic changes during esophagectomy
cardiac/great vessel compression
vagal stimulation
hemorrhage
dysarrthymias
PTX
epidural
synthetic liver fxn tests
- Albumin 2-3 week half life 3.5-5.5
- PT: measures 2 7,,10 (7 half life 4-6 hrs)
halothane hepatitis etiologt
hepatitis 2/2 oxidatitve metabolites such as trifluroacetic acid, and they induce autoimmine response or hve direct hepatotoxic effect
RF: F middle age, obese, repeated exposure
iso des 1:300,000 vs halothane 1:35,000
Functions of the liver
- metabolism carbs, fats proteins
- synthesis of serum proteins-albumin/clotting factors
- metabolism of drugs hormones, toxins (Phase 1-oxidation/reduction (benzo barbs), Phase 2 (conjugation-morphine)
- production urea and bile (absorption ADEK)
factors that effect HBF
how to preserve hepaptic blood flow intraop
- hypotension (RA GETA
- vasoconstriction of HA or GI/splanchnic circ 2/2 sympathetic stim
- BB that block B2 mediate HA vasodilation
- alpha agonists that cause HA and PV vasoconstriction
- excessive PEEP or postive pressure (increased hepatic venous pressure, decreased venous return
- H2 blocks decrease HBF
- direct surgical compression
maintain euvolemia, avoid hypotension, use iso (reduces portal flow least), min sympathetic stim, avoid BB and alpha agonist if possible
What is cirrhosis?
Head to toe effects
heapatic necrosis, fibrosis, and nodal regeneration/ leading to portal HTN >10mmHg. causes ETOH, hepatitis, toxins
Anesthesia:
1) paralysis: may need more larger initial dose due to larger VD, decreaed proetin binding larger free fraction may off set this, and impaired metabolism few doses may be needed
2) citrate intoxication more likely w blood
3) psueocholinesterase def
Neuro: encephalopathy AMS, asterxisis, hyperreflexa, wernicke korsakoff (more permeable BBB, ammonia broken down from blood in GI tract or transfusion)
Cards: hyperdynmaic state =high mixed venous(increased CO, low SVR, anemia, systemic shunts), systemic AV shunts
resp: decreased FRC and restrictive dz from ascites, increased AV shunts, plerual effusions, inhibition of HPV (from vasodilating substances - VIP, glucagon)–>hypoxemia, resp alkalosis
GI: Portal HTN causing 1) ascities (2/2 portal HTN, hypoalbumin, renal rentention of fluids),2) varices/hemorrhids, aspiration risk
renal: decrease renal perfusion, sodium retentiom. (increase in total body andvolume but decrease in effective volume, HRS (prerenal oliguria w NA retention, azotemia, and ascites
Heme: thrombocytopenia (splenic sequestration), anemia (bleeding, RBC destruction, malnutrition, SBP
Electrolytes: hyponatremia (dilutional), hypokalemia (diuresis or hyperaldosteronism), hypoalbumin, hypoglycemia
esophagel cancer considerations
cardio: often after ETOH and smoker, high risk post op a fib
pulm: smokers often, chronic aspiration–>pulm fibrosis,
GI: nutrional status poor (increased MM), liver fxn, aspiration risk (obstruction, altered motility and spincter dysfunction
chemo: doxorubicin (cardiomyopathy, belomycin lung, radiation (pnumonitis, pericarditis
medical management of PHTN and varicela hemorrhage
BB (propranolol), or isosorbide if BB not tolerated, TIPS
variceal bleed: vasoconstriction-somatostatin, octreotide (lower portal pressures) via vasocosnstrction; vasopressin, sclerotherapy, ligataion, balloon tamponade,
causes of hepatitis
ETOH,
halothane, amiodarone,
rifampin, INH
steriods, OCP
concerns with chronic alcoholics
Anesthesia: intoxiciation effect on MAC
neuro: AMS, encephalopathy, wernicke korsaoff (ataxia, confusion, occular issues; tx thiamine), withdrawl (sezizures DT)
cards: acute HTN tachy; cardiomyopathy, arrythmia
resp: smoker?
gi: ulcer, cirrhosis, aspiration risk
heme: pancytopenia
goals fir a cirrhoric pt
preop
- determine extent of multisystem dz
- optimize the pt: encepalopathy volume status, hyperdynamic state, hypoxemia, coaguopthy, anemia, electrolytes,
- delay if active hepatitis
intraop
- increased aspiration risk
- anesthetic that accounts for impaired hepatic drug clearance, increased VD, decreased protein binding, and altered MAC
- careful fluid management: low oncotic pressure predisposes to pulm edema need adeuquate hydration to preserve hepatic and renal perfusion
- have blood available to treat bleeding and coagulopathy from thrombocytopenia
post op
- AMS withdrawl or enceph
- same as above
Labs for cirrhotic
- CBC plt, PT PTT -pancytopenia from plt sequestration, anemia from bleeding, malnutriion and RBC destruction, coagulopathy from factor def
- electrolytes: BUN cr, glucose, na, K-hyponatremia from dlution, hypokalemia from diuresis and hyperaldosteronism, hypoglycemia from severe liver failure, azotemia from dehydration or HRS
- LFT for baseline values and albumin
why are cirrotics hypoxic
- atelectasis, restrictive lung dz, low FR from ascites
- attenuation of HPV via vasodilators, intrapulmonary A shunts
- plerual effusions,
Stages of liver transplant/complications
how to reduce reperfusion
- preanhepatic- dissection
bleeding
- anheppatic-liver is seperated from circulation and replaced w donor
- clamp IVC above and below, hepatic artery, PV
- CO drops, distal venous pressure increases
- consider V-v bypass
- complications-embolism of air/clots, bleeding/coagulopathy, hypothermia, citrate intoxication, acidosis, RF, brachial plexus injury - transplanted liver connected to circulation
- clamps removed, HA reanastamosed, CBD reconnected
- complications: hyperkalemia, acid metabolites/vasoactive suvstances kfrom lower body,cold blood, cytokines
- flush graft prior to reperfusion, current any current met acidosis to counter acid load from graft, admin calcium ro counter effects of K on heart, admin vasopressors/inotropes to correct any prexisting hypotension