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Ch.32 Anesthesia for Patients with Renal Disease. R1 한진희. Diseases affecting the kidneys Nephrotic syndrome Acute renal failure Chronic renal failure Nephritis Nephrolithiasis Urinary tract obstruction Infection 마취관리에 있어서는 syndrome 보다는 preoperative renal function 에 따라 분류하여야 함.
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Diseases affecting the kidneys • Nephrotic syndrome • Acute renal failure • Chronic renal failure • Nephritis • Nephrolithiasis • Urinary tract obstruction • Infection • 마취관리에 있어서는 syndrome 보다는 preoperative renal function에 따라 분류하여야 함
BLOOD UREA NITROGEN(BUN) • Primary source of urea : liver • Protein catabolism 과정에서 ammonia 생성 • Hepatic conversion을 통해 ammnia가 urea로 바뀌어 toxic ammonia level을 방지 • BUN은 protein catabolism이 정상이고 일정하여야 GFR의 reliable indicator 역할 가능 • 여과량의 40-50%가 renal tubule에서 passively reabsorbed 됨 (hypovolemia시 증가) • NL BUN concentration : 10-20mg/dL • Lower values : starvation, liver disease • Elevations : decreases in GFR, increases in protein catabolism (high catabolic state – trauma or sepsis) • 50mg/dL 이상일 경우 대개 renal impairment 관련
SERUM CREATININE • Creatine : product of muscle metabolism • Nonenzymatically converted to CREATININE • Creatinine production은 비교적 일정하며 muscle mass와 연관됨 • 평균 20-25mg/kg in men, 15-20mg/kg in women • Not reabsorbed in kidneys • NL serum creatinine concentration • 0.8-1.3mg/dL in men, 0.6-1mg/dL in women • Large meat meals, cimetidine therapy, increases in acetoacetate (ketoacidosis)시에 GFR의 변화 없이도 serum creatinine 증가 • GFR은 연령에 따라 감소 (5% per decade after age 20) • Muscle mass 또한 감소하므로 serum creatinine은 비교적 정상 유지 • Acute changes in GFR 후 48-72이 지나야 새로운 level에 평형 이룸
BUN : CREATININE RATIO • Low renal tubular flow rates시 urea reabsorption은 증가되지만 creatinine handling에는 영향이 없음 • BUN to serum creatinine ratio가 10:1 이상으로 증가 • BUN : creatinine ratio > 15 : 1 • Volume depletion, edematous disorders (heart failure, cirrhosis, nephrotic syndrome), obstructive uropathies
CREATININE CLEARANCE • Creatinine clearance measurements most accurate method available for clinically assessing overall renal function • 40-60mL/min : Mild renal impairment • 25-40mL/min : moderate renal dysfunction • Nearly always cause symptoms • Less than 25mL/min : renal failure • Progressive renal disease 시에는 proximal tubule에서의 creatinine secretion이 증대됨 • 점차 GFR을 overestimation 하게 됨
URINALYSIS • Routine urinalysis • pH • Systemic acidosis with urinary pH > 7.0 : renal tubular acidosis • Specific gravity • 1.010 corresponds to urinary osmolality 290 mOsm/kg • Overnight fast 후 1.018 이상 : indication of adequate renal concentrating ability • Glucose, protein, bilirubin의 detection & quantification • Proteinuria : 24-h urine collection 필요 • Urinary protein > 150mg/d significant • Elevated levels of bilirubin : biliary obstruction • Urinary sediment에 대한 microscopic examination • Red cells, white cells, bacteria • Tubular casts : disease processes at the level of the nephron
INTRAVENOUS AGENTS • Propofol & etomidate • Not significantly affected by impaired renal function • Hypoalbuminemia 시 etomidate의 protein binding 감소하여 effects 증가 • Barbiturates • Induction시 sensitivity 증가 • Protein binding이 감소하여 free circulating agent 증가 • Acidosis시 nonionized fraction이 증가하여 brain으로 보다 빠르게 들어감 • Ketamine • 일부 active hepatic metabolites가 renal excretion • Potentially accumulate in renal failure • Secondary hypertensive effect 주의 요함 • Benzodiazepines • Hypoalbuminemia시 sensitivity 증가 • Opioids • Morphine & meperidine : significant accumulation of active metabolites • Prolong respiratory depression • Normeperidine (meperidine metabolite) 증가시 seizures와 연관
INTRAVENOUS AGENTS (2) • Anticholinergic agents • Atropine & glycopyrrolate의 predemication dose는 안전하게 사용 가능 • 이러한 약제의 50%가량과 active metabolites는 urine으로 배출 repeated dose시 potential for accumulation • Scopolamine : renal excretion에 덜 의존적 • Azotemia시 CNS effect 증가됨 • Phenothiazines, H2 blockers, & related agents • Phenothiazines • azotemia시 potentiation of central depressant effects can occur • Antiemetic action이 도움 될 수도 있음 • Droperidol : partly dependent on kidneys for excretion • H2 blockers : very dependent on renal excretion • Metoclopramide : partly excreted unchanged in urine
INHALATION AGENTS • Volatile agents • Enflurane and sevoflurane (with < 2L/min gas flows) undergoing long procedures potential for fluoride accumulation • Nitrous oxide • Renal failure시 50%로 제한 • Anemia시 arterial oxygen content 증가시키기 위해 (hemoglobin < 7g/dL)
MUSCLE RELAXANTS • Succinylcholine • Induction시 serum potassium 농도가 5mEg/L 이하일 경우 renal failure에서도 안전하게 사용 가능 • Cisatracurium, atracurium, & mivacurium • Cisatracurium & atracurium • Enzymatic ester hydrolysis & nonenzymatic Hofmann elimination • Renal failure시 drugs of choice • Vecuronium & rocuronium • Vecuronium : 20%는 eliminated in urine • Rocuronium : hepatic elimination • Severe renal disease시 prolongation 될 수 있음 • Curare : 40-60%가 urine으로 excretion • Pancuronium, pipecuronium, alcuronium, & doxacurium • Primarily dependent on renal excretion (60-90%) • Metocurine, gallamine, & decamethonium • Entirely dependent on renal excretion • Should be avoided in impaired renal function • Reversal agents • Edrophonium, neostigmine, pyridostigmine : renal excretion is the principal route
PREOPERATIVE CONSIDERATIONS • Acute renal failure • Rapid deterioarion in renal function retention of nitrogenous waste products (azotemia) • Prerenal : acute decrease in renal perfusion • Renal : intrinsic renal dis., renal ischemia, nephrotoxins • Postrenal : urinary tract obx. Or disruption prerenal & postrenal : reversible in initial stages • 대부분은 oliguria 발생 • Nonoliguric Pts. (urinary outputs > 400mL/d) • Tend to have greater preservation of GFR • Course • Oliguria lasts for 2 wks, followed by a diuretic phase
PREOPERATIVE CONSIDERATIONS (2) • Chronic renal failure • 적어도 3-6 개월에 걸쳐 progressive & irreversible decline in renal function • m/c cause : hypertensive nephrosclerosis, diabetic nephropathy, chronic glomerulonephritis, polycystic renal disease • Uremia– GFR decreases below 25mL/min • Clearnaces below 10mL/min (ESRD) : dependent on dialysis • On daily dialysis generally feel entirely normal • 대부분 1주에 3회 투석 • Cx • hypotension, neutropenia, hypoxemia, disequilibrium syndrome generally transient • Disequilibrium syndrome : transient neurological Sx이 특징적 rapid lowering of extracellular osmolality than intracellular osmolality
PREOPERATIVE CONSIDERATIONS (3)Manifestations of renal failure • Metabolic • Hyperkalemia, hyperphosphatemia, hypocalcemia, hypermagnesemia, hyperuricemia, hypoalbuminemia 등 • Water & sodium retention • High anion gap metabolic acidosis • Hyperkalemia : most lethal • 대개 creatinine clearances < 5mL/min일 때 발생 • Large potassium load 있을때도 발생 가능 • Trauma, hemolysis, infections, potassium administration • Hematological • Anemia : creatinine clearance < 30mL/min일 때 • Hb 6-8g/dL • Edcreased erythropoietin production, decreased red cell production, decreased cell survival • 2,3-diphosphoglycerate (2,3-DPG) • Hb에서의 oxygen 해리되는 것을 촉진 • Metabolic acidosis 또한 Hb-O2 dissociation curve를 right shift 시킴 • Symptomatic heart dis. 없을 경우 대개 well tolerate the anemia • PLT, WBC function are impaired • Prolonged bleeding time, increased susceptibility to infections • 최근에 hemodialysis 받은 환자의 경우 residual anticoagulant effects from heparin 주의
PREOPERATIVE CONSIDERATIONS (4)Manifestations of renal failure • Cardiovascular • Renal failure 시 oxygen delivery 유지 위해 cardiac output 증가되어야 함 • LVH – common finding • Congestive heart failure, pulm. Edema에 취약 • Sodium retention에 의한 extracellular fluid overload • Arrhythmias, uremic pericarditis • ARF의 diuretic phase에서는 intravascular volume depletion 발생되기도 함 • Pulmonary • Metabolic acidosis에 compensation위해 minute ventilation 증가됨 • Alveolar-capillary memb.의 permeability 증가에 따라 pulm. edema 생길 수 있음 • “butterfly wings” on chest film
PREOPERATIVE CONSIDERATIONS (5)Manifestations of renal failure • Endocrine • Abnormal glucose tolerance • Pph. Resistance to insulin 때문 • Secondary hyperparathyroidism • Metabolic bone disease 생길 수 있음 • Hypertriglyceridemia • Gastrointestinal • Anorexia, nausea, vomiting, adynamic ileus • Peptic ulceration & G-I hemorrhage • Delayed gastric emptying : predispose to aspiration • High incidence of viral hepatitis (B & C) • Neurological • Uremic encephalopathy의 menifestations • Asterixis, lethargy, confusion, seizures, coma • Sx은 대개 azotemia 정도에 따름 • Autonomic & peripheral neuropathies • Pph. Neuropathies : typically sensory, involve distal lower extremities
PREOPERATIVE CONSIDERATIONS (6) • Preoperative evaluation • 마취종류에 관계없이 complete evaluation 필요 • All reversible menifestation of uremia should be controlled • Preoperative dialysis : 수술 당일 or 전날 • Evaluation • Signs of fluid overload or hypovolemia • Pt’s current weight • Hemodynamic data, chest film • Arterial blood gas analysis – dyspnea 보이는 환자에서 • Detecting hypoxemia, evaluating acid-base status • ECG – signs of hyperkalemia, hypocalcemia • Echocardiography • Preop RBC transfusion • Only to severely anemic Pts. (Hb < 6-7g/dL) • Significant intraop. Blood loss is expected
PREOPERATIVE CONSIDERATIONS (7) • Premedication • Reduced doses of opioid or benzodiazepine • Promethazine, 12.5-25mg IM • Additional sedation, antiemetic properties • Aspiration prophylaxis • H2 blocker • Metoclopramide, 10mg orally or slowly IV
INTRAOPERATIVE CONSIDERATION • Monitoring • A-V fistula 있는 팔에서 cuff로 혈압 측정 금지 • Intraarterial, central venous, pulm. A. monitoring • Major surgery 예정인 advanced renal dis. 지닌 DM 환자 aggressive invasive monitoring • Induction • Rapid-sequence induction with cricoid pressure • Nausea, vomiting, G-I bleeding 있을 시 • Thiopental, 2-3mg/kg, or propofol, 1-2mg/kg • Etomidate, 0.2-0.4mg/kg : hemodynamically unstable Pts. • Opioid, β-blocker (esmolol), lidocaine • To blunt hypertensive response to intubation • Succinyulcholine, 1.5mg/kg • Serum potassium < 5mEq/L 시에만 사용 • Laryngeal mask airway avoids excessive sympathetic (hypertensive) response
INTRAOPERATIVE CONSIDERATION (2) • Maintenance • Ideally : control HTN with minimal effects on cardiac output • Volatile agents : isoflurane, desflurane • Nitrous oxide • Very low Hb (<7g/dL)시 100% oxygen 주기 위해 nitrous oxide 사용 안함 • Controlled ventilation • Inadequate spontaneous ventilation respiratory acidosis • Preexisting acidemia 악화 • Potentially severe circulatory depression • Dangerously increase serum potassium concentraion • Fluid therapy • Supf. Op. : only insensible fluid losses with 5% dextrose in water • Major fluid losses or shifts : isotonic crystalloids, colloids • Lactated Ringer’s injection : hyperkalemic Pt에서 금기 • Glucose-free solutions
ANESTHESIA FOR PATIENTS WITHMILD TO MODERATE RENAL IMPAIRMENT
PREOPERATIVE CONSIDERATIONS • Large reserve in function • GFR, creatinine clearance는 120에서 60mL/min까지 떨어져도 아무런 clinically perceptible change 없을 수 있다 • 목표 : maintaining normovolemia • Creatinine clearance가 25-40 mL/min에 이르면 renal impairment는 moderate renal insufficiency • Significant azotemia가 항상 있으며 HTN, anemia 흔함 • Relatively high incidence of postop. Renal failure • Cardiac and aortic reconstructive surgery • Intravascular volume depletion, sepsis, obx. jaundice, crush injuries, recent contrast dye injections • Aminoglycoside, ACEi, NSAIDs • Prophylaxis against renal failure • Generous hydration together with solute diuresis • In high-risk pts., cardiac, major aortic reconstructive surgery • Mannitol (0.5g/kg) : should be started prior to or at the time of induction • intravascular volume depletion 방지위해 iv fluid를 동시에 주입 • Fenoldopam or low-dose dopamine : increase renal blood flow • Small dose of loop diuretics • Acetylcysteine prior to radiocontrast dyes
INTRAOPERATIVE CONSIDERATIONS • Monitoring • Hourly urinary output, intravascular volume • Urine > 0.5mL/kg/h • Intraarterial pressure monitoring • Induction • Induction 전에 adequate intravascular volume 확인할 것 : preop. hydration • 약제 투여 후 hypotension은 대개 intubation이나 surgical stimulation으로 해결됨
INTRAOPERATIVE CONSIDERATIONS (2) • Maintenance • Exception of sevoflurane with low gas flows(<2L/min) • Deterioration in renal function 원인 • Surgery : hemorrhage • Anesthesia : cardiac depression or hypotension • Indirect hormonal effects : sympathoadrenal activation or antidiuretic hormone secretion • Positive pressure ventilation : impeded venous return 이들은 대부분 충분한 Iv fluid 투여로 completely reversible • Large doses of predominantly α-adrenergic vasopressors (phenylephrine, norepinephrine) 피할 것 • Renal blood flow 유지하는데 small intermittent doses or brief infusio는 효과적 • Fluid therapy • Judicious fluid administration • 대개 excessive fluid overload (pulm. Congestion or edema)가 ARF보다 치료하기 쉽다