SICU Case Discussion—Perioperative Renal Failure in Cardiac Surgery
Intern 許惠晴 Resident 李惠琴 醫師V.S. 張家昇 主任
Name: 莊先生Age: 82
Sex: male
Chart No.: 16448408
Date of admission: 2008/03/04
Basic Data
Present Illness
Sudden onset of upper back pain since 3 AMIntolerable pain without radiation brought to 埔基 H. CT: aortic dissection experienced bilateral legs numbness and right leg weakness transferred to our hospital On admission: severe back pain; not able to move his right leg; bedside doppler failed to sense blood flow over bilateral dorsal pedis, bilateral popliteal and right femoral artery.
Present Illness
Leg CTA: 1) Aortic dissection at lower abdominal aorta, 2) PAOD of both lower limb from bilateral external iliac arteries
Type B aortic dissection was diagnosed sent to OR
Past History
RCC, pT2N1M0 s/p R't radical nephrectomy + hilar lymph node excision + R't adrenalectomy on 96/10/02 3V-CAD s/p PTCA + stent to RCA Complete AV block s/p TPM in 96/08 Chronic renal failure Hypertension Gout
Lab data on 2008/03/04
RBC Hb HCT PLT.
3.41 9.9 29.4 143
WBC Seg Lymph Mono. Baso. Eos.
9.07 87 8.9 2.4 0.1 0.9
GPT Bil-T Glu-AC
14 0.55 166
BUN CREA NA K eGFR
40 2.57 136 5.1 19.4
Operative MethodRight axillo-femoral; femoral-femoral bypass
Operative Findingsno pulsation of rt’ common femoral artery
dissection with intramural hematoma over lt’ common femoral artery
equal artery pressure over bilateral subclavian artery
Hyperkalemia(K:6.5) and oliguria were noted at OR
ABG: PH 7.36, PaO2 274.5, PaCO2 38.6, HCO3 22.4, O2 sat 100.0%
Acute renal failure Consult nephrologist for CVVH
Perioperative Renal Failure in Cardiac Surgery
Incidence of Peri-operative ARF
occurs in up to 30% of all patients who undergo cardiac surgery, dialysis occurs in approximately 1%
7% after abdominal aortic reconstruction
3% after elective infrarenal aortic reconstruction, mortality greater than 40%
Acute tubular necrosis accounts for nearly all renal dysfunction and failure after aortic reconstruction.
The degree of preoperative renal insufficiency remains the strongest predictor of postoperative renal dysfunction.
Acute perioperative renal failure is most likely to occur in patients who have renal insufficiency before surgery, are older than 60 years, and have preoperative left ventricular dysfunction
General Measures to Prevent ARF
Optimization of systemic hemodynamics—
maintenance of intravascular volume the most effective means of renal protection
Hemodynamic monitoring
Avoid over-hydration
Avoid nephrotoxin
Use isosmolar contrast agents
Pharmacologic Intervention to Prevent ARF after Cardiac Surgery
Increase renal blood flow— low dose dopamine, fenoldopam
Induce natriuresis—ANP, mannitol, diuretics
Block inflammation—Pentoxifylline, N-acetylcysteine
Other—Clonidine, diltiazem, prophylactic hemodialysis
Loop diuretics and low-dose dopamine (1 to 3 μg/kg/min) have been advocated to protect the kidneys by increasing renal blood flow and urine failed to show benefit
Fenoldopam mesylate
A selective dopamine type 1 agonist that preferentially dilates renal and splanchnic vascular beds; has shown some early promise as a renal-protective agent .
causes natriuresis and increases renal blood flow and urine output
Atrial natriuretic peptide
anaritide
increases natriuresis by increasing GFR as well as by inhibiting sodium reabsorption by the medullary collecting duct
significant reduction in the incidence of dialysis at day 21 after the start of treatment (low rate, prolonged infusion)
Mannitol
to induce an osmotic diuresis
improves renal cortical blood flow
reduce ischemia-induced renal vascular endothelial cell edema and vascular congestion
acting as a scavenger of free radicals
decreasing renin secretion
increasing renal prostaglandin synthesis
N-acetylcysteine (N-AC)
shown to block inflammation and oxidant stress in cardiac surgery patient
may hold promise as a simple, nontoxic protective measure
Not proven yet.
Prophylactic hemodialysis
Single study
Creatinine > 2.5 mg/dl
Perioperative prophylactic dialysis vs. Dialysis only when postoperative ARF that indicated the procedure
Mortality: 4.8 vs.30.4%
Need more study
Inh. Sym. tone
Inh. InflammPrevent vasospasm
Continuous Renal Replacement Therapy
Arteriovenous: external shunt, without the absolute need of a blood pumpVenovenous: catheter, require a blood pumpCVVH: hemofiltration; removal of fluid and waste occur by entirely by convection or bulk flow, transmembrane pressure governs the amount of fluid and dissolved waste being ultrafiltered across the membrane
Continuous renal replacement therapy(CRRT)
YesRF/DYesContinuous venovenous hemodiafiltration(CVVHDF)
YesDYesContinuous venovenous hemodialysis(CVVHD)
YesRFYesContinuous venovenous hemofiltration(CVVH)
NoRF/DNoContinuous arteriovenous hemodiafiltration(CAVHDF)
NoDNoContinuous arteriovenous hemodialysis(CAVHD)
YesNoneYes/noSlow continuous ultrafiltration(SCUF)
Intraoperative Use
Replacement Fluid (RF)/Dialysate (D)
Blood Pump
Renal Replacement Therapy
Reference
Brenner & Rector's The Kidney, 7th ed.
Miller's Anesthesia, 6th ed.
Acute Kidney Injury Associated with Cardiac Surgery, Mitchell H. Rosner, Clin J Am Soc Nephrol 1: 19–32, 2006.