Liver failure/CABG/ESRD Flashcards
MELD score
used to prioritize organ allocation to adult pts
NBC-I
Na, bili, Cr, INR
platypnea
dyspnea worsening in the upright position
hepatopulmonary syndrome
liver disease
decrease oxygenation (PaO2 < 70)
intrapulm vascular dilation (pulm angio, perfusion lung scan)
dyspnea in End stage liver disease
heptopulm syndrome
pleural edema
alcoholic cardiomyopathy
cirrhotic cardiomyopathy
2/2 smoking or COPD
or a combo
perks of paracentesis preop
-inc cardiac output (relieves compression on IVC)
-improved pulm gas exchange (inc pulm compliance, dec V/Q mismatch)
-dec risk of aspration (stomach compression)
**ensure adequate volume expansion w/ colloids
Diagnosis of hepatorenal syndrome
- presence of advc liver dx and portal HTN
- lower GFR Cr > 1.5 or GFR < 40
- absence of shock, infxn, fluid loss, or nephrotoxic agents
- no sustained improvement in renal function w/ administration of fluids/albumin
- no proteinuria, urinary obstruction or parenchymal renal dx
pathophysiology of hepatorenal syndrome
portal HTN -> relase of vasodilators substances (nitric oxidee) -> splanchnic arterial vasodilation -> activation of the renin-angiotensin-aldo system -> inc absorption of water and Na and kidney vasoconstriction -> contuined decreased perfusion to kidneys
Type I: rapidly progressive w/i 2 weeks
type II: slower onset
Meds to help w/ hepatorenal syndrome while waiting for transplant
albumin (volume expander)
midodrine (vasoconstrictor)
octreotide (inhbits splanchnic vasodilation)
moderate pulm HTN
35-45
pulm HTN
> 25
pulm pressure CI to liver transplant
> 50
Concerns w/ hepatic encephalopathy and anesthesia
-hypoK: can inc production of ammonia, make it worse
-maintain normal pH -> alkalemia can inc diffusion of ammonia across BBB
-correct hypovolemia or anemia: optimize liver metabolism of circulating toxicns
-careful w/ benosz: suppresion of CNS can exacerbate his condition
pathophysiology of hepatopulmonary syndrome
portal hypertension -> hyperdynamic circulation and fluid overload -> splanchnic volume overload and bowel edema -> bacterial translocation and cytokine activation -> inc activation of macrophages in lungs -> inc/accumulation of nitric oxide to promote vasodiatlion w/ accumulation of MP -> abnormal pulmonary dilation and blunting of HPV
Goals for coags preop in end stage liver dx
plts > 50-60,000
INR < 1.5
no signs of active bleeding
veno-veno bypass in liver transplant
femoral and portal veins are cannulated to reroute blood flow from below the diaphragm to the suprahepatic vena cava (axillary, subclavian or jugular vein)
-minimizes interruption of caval flow from anhepatic phase
-adv: improved cardiac filling, dec blood and fluid requirements, improved surgical field
-disadv: inc risk of air embolism, thromboembolism, arm lymphedema, hematoma, vascular/n inury
succinylcholine and end stage liver dx
-can use due to inc risk of aspiration to secure airway as soon as possible
-however maybe prolonged due to reduced production of pseudocholinesterase
(FFP provides additional pseudocholinesterase)
stages of liver transplant
preanhepatic: liver dissected and mobilized until only attached by IVC, portal vein, hepatic a, and CBD
-anhepatic phase: clamping of the hepatic artery, until implantation of new liver
-post-anhepatic phase: reperfusion to completion of surgery
start of anhepatic phase, surgeon clamps IVC BP dec to 78/44, what to do?
-communicate w/ surgeon, have them release the clamp -> hypoTN most likely due to dec preload
-also can be other causes: FiO2 100%, auscultate lungs, verify ETT placement, give fluids and vasopressors
-discuss w/ surgeon possibility of veno veno bypass -> if not fluids and ensure presence of vasopressors
anhepatic peaked T waves widened QRS, what’s going on
hyperK: combo of acidemia w/ clamping, dec UOP of K, reduced hepatic uptake of K, K in blood produces, and K containing solution
-order a K level, let surgeon know, and start treatment
-give calcium, ensure access to cardiac defibrillator, correct acidosis, hypocalcemia, give insulin and glucose, albuterol, and bicarb
-hyperventilate
-consider HD if insufficient
hypoCa under GA
widened QRS complexes
hypoTN
narros pulse pressure
prolonged QT
elevated CVP
flattened T waves
Treatment of hypoCa w/ citrate toxicity
give calcium chloride or gluconate
-correct hypothermia
-tx hypoTN and arrhythmias
hypoTN at beginning of reperfusion w/ liver transplant
removal of vascular clamps w/ postperfusion syndrome -> hypoTN, bradycardia, arrhythmias, elevated pulm a pressures
-hemorrhages, tension PTX, CHF, hyperK
What causes reperfusion syndrome
excessive K in graft
release of vasoactive substances and acidic metabolites from graft and lower extremities
cold blood from graft
cytokines
how to reduce reperfusion syndrome
careful flushing of graft before reperfusion
give bicarb
correct metabolic acidosis
calcium
inotropes or vasoconstrictors
potential postop complications w/ liver transplant
-bleeding varices
-vascular anastomic leake
-coagulopathy (DIC, residual heparin, dilution coagulopathy)
renal dysfxn
CHF
TRALI
pulm edema
biliary complications
hepatic or portal vessel thrombosis
encephalopathy
peripheral n injury
infxn
graft failure or rejection
