Renal Replacement Therapy Considerations for the Internal Medicine Resident Mini-Lecture Series UC Irvine Dept of Medicine 10 March 2014

Goals/Objectives To assist medical decision-making in acute renal failure To understand the role of renal replacement therapy in the inpatient setting. To make cognizant possible complications from dialysis and potential challenges in the management of patients undergoing dialysis

Case 56yo F presents to the emergency room with weakness and altered mental status. She has known chronic kidney disease stage V believed to be due to hypertension and uncontrolled diabetes and was evaluated by nephrology one month prior as an outpatient with discussions at that time to prepare for renal replacement therapy.

One month ago Na137WBC11.6 K4.8Hb9.0 Cl105Hct26.3 CO221Plt251 BUN48 Cr3.1 Glucose97 Ca7.8 Mg1.9 Phos8.0 Na129WBC17.8T. Protein5.4PT11.5 K5.9Hb5.9Alb2.4aPTT38.9 Cl101Hct18.2Alk Phos106INR1.08 CO215Plt192T. Bili0.5 BUN90AST16 Cr5.5ALT11 Glucose49 Ca6.0 Mg1.8 Phos8.5 Today ABG on 2L NC: 7.22/40.1/145/15

Case Physical exam shows normal vital signs. She is an obese female who was lethargic but alert and oriented x4. Physical examination was otherwise unremarkable including rectal examination, which was negative for masses or bleeding. Hypoglycemia is addressed by witholding all insulin and providing dextrose source.

Given: o Acute drop in hemoglobin o Acute kidney injury o Acidemia o Altered mental status o Hyperkalemia Do you call nephrology?

Indications “A-E-I-O-U” o Acidosis o Electrolyte Disturbance o Intoxication o Overload o Uremia Consult nephrology with any of these life threatening conditions.

Modalities Intermittent hemodialysis (IHD) Continuous renal replacement therapy (CRRT) Sustained low-efficiency dialysis (SLED) Peritoneal dialysis (PD)

Complications and Challenges Dialysis catheter-related problems Hypotension Arrhythmias Dialyzer reactions Problems with CRRT Drug Dosing Adjustments

Intradialytic Hypotension More often seen with IHD, although can be a result of all modalities Etiology – intravascular depletion o Rapid clearance of uremic solutes decrease serum osmolality—thereby, driving fluid intracellularly o Don’t forget to rule out any other underlying etiologies, like sepsis! Air embolus! Initial management options o Fluid bolus 250 ml +/- 25% albumin o Turning off dialysis o Decreasing dialysate temperature to promote vasoconstriction o Communicate with Nephrology

Arrythmia Etiology o Rapid shift in electrolytes o Ultrafiltration of antiarrhythmic drugs Digoxin/digitalis If arrhythmia is resulting in hemodynamic compromise, stop dialysis immediately and cardiovert

Dialyzer Reactions Type A – anaphylactic o Rare: 4 of every 100,000 sessions o Presents in the first few minutes o Symptoms varies: urticaria, flushing, chest pain, back pain, vomiting, chills o Etiology: due to residual amounts of ETHYLENE OXIDE (used to sterilize dialyzers) o Management: discontinue dialysis; treat anaphylaxis Type B o More common; less severe: 4 of every 100 session o Presents after the first 15 minutes o Symptoms: chest pain, back pain, dyspnea, GI symptoms o Etiology: due to unsubstituted cellulose dialyzer membranes and activation of complement. o Management: if symptoms resolve, continue dialysis with supportive care.

Dialysis Catheter-Related Problems Bacteremia! Thrombus or fibrin sheath formation within or around catheter o Consider Heparin or Alteplase Do not use subclavian vein catheters o There is a high risk of stenosis, preventing the option of a future AV fistula or graft in that extremity.

Problems with CRRT Electrolytes – Check at least TWICE daily o Hypophosphatemia o Hypokalemia o Hypomagnesemia Anticoagulation o Heparin o Argatroban o Citrate Hypothermia o Warm the replacement fluid or blood

Drug Dosing In general, removal of drugs on IHD, CRRT, or PD has not been tested It is based theoretically on molecular weight and chemical composition. Consult with the pharmacist and with nephrology

Return to the CASE No evidence of bleeding. Nephrology was made aware of the patient but no decision for dialysis was made. If there were evidence of bleeding, urgent dialysis may have been appropriate. In this patient’s case, with worsening renal function, she likely experienced sulfonylurea toxicity contributing to hypoglycemia Anemia likely 2/2 chronic kidney disease Acidemia was medically managed with sodium bicarbonate supplementation.

References Kollef, et al. Washington Manual of Critical Care 2 nd Edition UpToDate: Renal Replacement Therapy in Acute Kidney Injry in Adults: Indications, Timing, and dialysis dose. Wilson, Samuel Eric. Vascular Access: Principles and Practice 5 th Edition Holubek, et al. Use of Hemodialysis and Hemoperfusion in Poisoned Patients 2008 Kidney International