1. Renal Failure Rebecca Burton-MacLeod R5, Emerg Med Nov 8th, 2007

2. Overview of RF Renal Failure Chronic renal failure Acute renal failure Acute on chronic renal failure

3. Acute renal failure • 2 main renal physiological functions that are easily measured in ED: • Urine output • Excretion of water soluble waste products of metabolism • Therefore, definition of ARF: • Decline in Cr clearance of 50% • Increase in serum Cr of 50% • Renal insult causing pt to require dialysis

4. ARF • May have anuric (<100cc/24h), oliguric (<0.5cc/kg/h), or non-oliguric renal failure • Mortality lower with non-oliguric renal failure; however, may still have renal failure with NORMAL urine output!!

5. Pre-renal (most common; 55% hosp pts) Intravascular depletion (hemorrhage, dehydration, diuresis, GI losses, skin losses) Vasodilation or dec cardiac output (sepsis, anaphylaxis, nitrates, antihypertensives, liver failure) Post-renal (obstruction anywhere along UT) Renal calculi Urethral valves VUR Cervical Ca or pelvic inflammation Prostatic disease Etiology

6. Etiology: renal causes • ATN (ischemia, rhabdo, toxins—contrast, aminoglycosides, NSAIDs, ACEi, ARBs, tacrolimus, cyclosporine, cisplatinum, heavy metals, ethylene glycol, cocaine) • Interstitial insult (adverse drug rxn, often assoc with fever, rash, jt pain) • Glomerular insult (glomerulonephritis) • Vascular insult (renal art thrombosis or stenosis, renal vein thrombosis, scleroderma)

7. History: Hx thirst GI losses Hemorrhage, burns, trauma Pancreas/liver disease Meds Recent illness Urgency/frequency/ hesitancy in males Physical: Vitals Volume status CV—dysrhythmia, s/s endocarditis Abdo—aneurysm, flank tender, bladder size Neuro—asterixis, LOC Derm—rashes, edema Differentiating causes

8. Diagnosing • Lytes, BUN, Cr • EKG • U/A, Urine lytes • U/S +/- CT KUB

9. U/A • Casts: • Hyaline—generally assoc with pre-renal or post-renal obstructive causes • RBC—always significant; assoc with glomerulonephritis • WBC—renal parenchymal inflammation • Granular—cellular remnants and debris • Fatty—nephrotic s/o or other nonglomerular renal disease

10. Urine Na Fractional excretion Na (Urine Na x plasma Cr) / (plasma Na x urine Cr) Affected if mannitol or loop diuretics administered Urine Na <20 and FENa <1% Pre-renal failure, acute obstruction, contrast-induced ATN, rhabdo-induced ATN, nonoliguric ATN Urine Na >40 and FENa >1% ATN, chronic obstruction, underlying CRF Urine lytes

11. Prevention • Adequate volume replacement • Foley/percutaneous nephrostomy • Avoid nephrotoxic agents if possible, or else use OD dosing • Renal-dosing dopamine in conjunction with lasix may aid in converting oliguric to non-oliguric RF • Consider low-dose vasopressin in sepsis

12. Management of specific problems • HyperPh: give oral Ca antacids which bind to Ph • Symptomatic hypoCa: 10cc of 10% Cagluconate IV • HyperK: if >6.5 and EKG changes…be aggressive! • Volume overload: diuretics, nitrates, dialysis

13. Indications for dialysis with ARF • Fluid overload in oliguric/anuric RF • HyperK • Severe acidemia • Uremic encephalopathy • Toxins: ethylene glycol, methanol, ASA, Li, theophylline

14. Prognosis in ARF • If receive dialysis for ARF then 16% remain dialysis-dependent • Also, 40% of pts develop CRF

15. Chronic renal failure • Definition: • CRF—GFR <60cc/min, but decreased by <75% • ESRD—GFR <10cc/min, serious life-threatening complications without dialysis or transplant

16. Etiology • DM (45%) • Hypertension (30%, up to 40% in black popn) • Glomerulonephritis • Collagen vascular disease (SLE, scleroderma, Wagners) • Hereditary (PCKD, Alports s/o) • Obstructive uropathy (BPH, retroperitoneal tumor, nephrolithiasis) • HIV • Nephrotoxins (contrast, heroin, ampho B, aminoglycosides) • Peds—reflux nephropathy

17. Complications • Uremia • Renal osteodystrophy • Normocytic normochromic anemia • Infections (impaired WBC function) • GIB (stress ulcers and impaired hemostasis) • Pericarditis (up to 20% of dialysed pts)

18. What ? Do you need to ask… • Dry weight? • Dialysis schedule? • Form of dialysis (hemo, peritoneal)? • Missed dialysis?

19. Mgmt of specific disorders • Cases…

20. Case 1 • 68yo F with sharp lower abdo pain x2d, worsening. Small amount of blood in stool this a.m. • You’re convinced you need a CT abdo. Speak to Radiol. They ask what her Cr is… • ….long pause…..142…. • Do you still want CT? What are your options?

21. Contrast nephropathy • Risk factors—DM, underlyling renal d/o, amyloidosis, MM, hypo-proteinuric states, larger doses of contrast, repeat exposures to contrast <72hr, type of contrast • NAC? • Bicarb?

22. Papers… • Several studies done looking at benefit of NAC vs. bicarb vs. saline for prevention of contrast nephropathy

23. N=264; received either bicarb infusion, or N/S infusion, or NAC and N/S infusion • 6 hrs pre and post angio • Baseline Cr 139 • Change in Cr clearance significantly better with bicarb than with other regimens

24. Cont’d

25. DBRCT n=326 pts undergoing angio • All had chronic renal disease • Protocols: 1) N/S x12 hrs pre and post and NAC 2) bicarb x1h pre and 6h post and NAC 3) N/S and ascorbic acid and NAC • All pts had NAC day prior to procedure and days after

26. Cont’d • Outcome: • In N/S and NAC: 9.9% developed CN • In bicarb and NAC: 1.9% developed CN • In N/S and ascorbic acid and NAC: 10.3% CN • Bicarb and NAC significantly better in medium to high risk pts for CN

27. N=118 with Cr >110 • Bicarb 3ml/kg/h x1h prior then 1ml/kg/h x6h post vs. N/S infusion as above • Significantly greater nephroprotective effects from bicarb • Postulated due to inc flow, local tubular alkalinization, partial correction of ischemic acidosis

28. Case 2 • 72yo M presents c/o chest pain, weakness. At triage, HR noted to be 32. • Brought back to monitored bed. • Hx of DM, hypertension, recent w/u for back pain • Meds: metformin, lasix, propanolol, penicillin, one other med he can’t remember the name of…

29. Case cont’d • O/e: HR 34, SBP 86, RR 16, sats 93% • Pt pale, slightly diaphoretic; nil else remarkable on exam • BG—6.8 • Plan?

30. EKG Any thoughts ? Plan ?

31. Case cont’d • ABG– K 9.8 • Cr 589

32. HyperK in RF • CaCl 5cc IV bolus, rpt q5min prn • ?is he on digoxin? • Bicarb 50meq IV, rpt x1 prn • Watch for volume overload!! • Ventolin nebs, rpt or continuous • Insulin—give 10-20U Hum R mixed with glucose • Use D20 or D50 to decrease volume • Kayexalate, mixed with sorbitol • Watch for Na overload as exchanges K for Na • IV diuretics • Only works if residual renal function! • Dialysis!!!

33. How quickly will K drop? • Insulin drops K by 1meq/L after 1h • IV Ventolin drops K by 1.1meq/L after 15min • Dialysis: • Hemodialysis—removes up to 50meq/h • Peritoneal dialysis—removes 15meq/h

34. Case 3 • 47yo F hemodialysis patient presents to ED c/o SOB • Last dialysis 5d ago (missed one because travelling back from US); states weight up 6lbs • O/e: HR 110, BP 145/87, sats 88% r/a • Tachypneic, ++crackles to bilat lungs, elevated JVP • You call her Nephrologist…waiting for them to get back to you… • Plan?

35. Pulmonary edema • Hemodialysis… • Oxygen, sitting position • Consider CPAP • Nitrates: SL, IV or nitroprusside • Lasix 60-100mg IV (for pulm vasodilation) • +/- IV morphine • Sorbitol 70% 50-100cc dose q20-60min (causes osmotic shift into gut) • Hemodialysis…

36. Case 4 • 59yo M presents to ED c/o cough, SOB, fever x3d • Mild chest pain, no abdo pain, no n/v • PMHx: hemodialysis pt, DM, pacemaker • O/e: HR 115, SBP 95, RR 30, sats 95% r/a • Slight JVD, normal HS, lungs clear, abdo soft • Investigations?

37. CXR Old XR (1y ago) Today

38. EKG

39. Uremic pericarditis • Aggressive volume support • Indomethacin • Hemodialysis ++++++ • +/- pericardiocentesis (if unstable) • +/- steroid instillation

40. Case 5 • You get a call from dialysis unit. They’re mid-way thru a run of HD with a pt who has now developed hypotension. They can’t get a hold of Nephro and are not sure what to do with the pt. • You asked if they’ve slowed the rate and amount of ultrafiltration (duh!)… • They want to send him down to ED…

41. Cont’d • Before the pt even arrives, you’re thinking Ddx: • Hypovolemia (dialysis related, GIB, hemorrhage) • CV causes (MI, dysrhythmias, tamponade) • Lyte d/o (Ca, Mg, K) • Air embolism • Hypoxemia • Drugs (narcotics, antihypertensives, anxiolytics) • Hypersensitivity rxn (to ethylene oxide which sterilizes dialyzer, polyacrylonitrile in the membranes) • Autonomic neuropathy • Acetate-based dialysate

42. Mgmt of hypotension • Obviously, decrease flow rate and amount of ultrafiltration • N/S IV bolus: 250-500cc in small boluses of 100-200cc and frequently reassess! • Try to figure out why…

43. Case 6 • 86yo F presents to ED c/o high BP. Says she takes her BP at home regularly and today it was 195/115. She’s been told this is “too high”. You go in to take a quick hx…nothing exciting. Nurse has not checked pt in yet. • O/e: NAD. Lungs nil acute. CV nil acute. Abdo nil acute. Skin—note made of Cimino-Brescia fistula in L arm with thrill present • You ask for a set of vitals and disappear to see your next pt…

44. Cont’d • You come back a while later and find the BP cuff cycling q1min measuring her BP…last one 158/90. • It’s cycling on her L arm…any problem? • You check her fistula site and notice there is no longer a thrill, but still feel a strong palpable pulse. Concerned?

45. Thrombosis of access • Avoid manipulating access site, as may cause venous embolization • Call Vascular • Occasionally they may use thrombolytic agents to open thrombosed access but usually surgical revision required • Bottom line: don’t put tourniquet, check BP, or circumferential bandages on arm with fistula!!

46. Case 7 • 43yo M presents to ED c/o generalized abdo pain, malaise. He has a peritoneal dialysis line in place. Last seen by Nephro about 3wks ago, everything going well. Very conscientious about his peritoneal catheter and keeping it sterile! • ROS: small amount of foul urine produced, diarrhea x1 yest, sore throat ~1wk ago

47. Cont’d • O/e: T 38.2, HR 92, BP 142/78, sats 98% • Lungs clear, HS normal, H+N small cervical lymphadenopathy, abdo sl distended, catheter site appears clean, mild abdo tenderness, no guarding, no rebound • Investigations?

48. Cont’d • CBC, lytes, Cr, lipase • Dialysate analysis • U/A

49. Results • WBC 12 • Lytes N, Cr 327, lipase N • U/A--+RBC, +leuks, +WBC and granular casts • Dialysate—cloudy, 105 WBC, 60% neuts, Gm stain pending

50. Peritonitis • 70% of cases caused by staph aureus or staph epidermidis • If polymicrobial infection, then suggests direct contamination from GI tract and should search for perf or fistula! • Usually can be easily treated as oupt and does not require removal or replacement of catheter