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
Today
Na
137
WBC
11.6
Na
129
WBC
17.8
T. Protein
5.4
PT
11.5
K
4.8
Hb
9.0
K
5.9
Hb
5.9
Alb
2.4
aPTT
38.9
Cl
105
Hct
26.3
Cl
101
Hct
18.2
Alk Phos
106
INR
1.08
CO2
21
Plt
251
CO2
15
Plt
192
T. Bili
0.5
BUN
48
BUN
90
AST
16
Cr
3.1
Cr
5.5
ALT
11
Glucose
97
Glucose
49
Ca
7.8
Ca
6.0
Mg
1.9
Mg
1.8
Phos
8.0
Phos
8.5
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
o
o
o
o
Acute drop in hemoglobin
Acute kidney injury
Acidemia
Altered mental status
Hyperkalemia
Do you call nephrology?
Indications
• “A-E-I-O-U”
o
o
o
o
o
Acidosis
Electrolyte Disturbance
Intoxication
Overload
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
o
o
o
Fluid bolus 250 ml +/- 25% albumin
Turning off dialysis
Decreasing dialysate temperature to promote vasoconstriction
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
Rare: 4 of every 100,000 sessions
Presents in the first few minutes
Symptoms varies: urticaria, flushing, chest pain, back pain, vomiting, chills
Etiology: due to residual amounts of ETHYLENE OXIDE (used to sterilize
dialyzers)
o Management: discontinue dialysis; treat anaphylaxis
o
o
o
o
• Type B
More common; less severe: 4 of every 100 session
Presents after the first 15 minutes
Symptoms: chest pain, back pain, dyspnea, GI symptoms
Etiology: due to unsubstituted cellulose dialyzer membranes and
activation of complement.
o Management: if symptoms resolve, continue dialysis with supportive care.
o
o
o
o
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 2nd
Edition. 2012
• UpToDate: Renal Replacement Therapy in Acute
Kidney Injry in Adults: Indications, Timing, and dialysis
dose.
• Wilson, Samuel Eric. Vascular Access: Principles and
Practice 5th Edition. 2012. 120-125.
• Holubek, et al. Use of Hemodialysis and
Hemoperfusion in Poisoned Patients 2008 Kidney
International