AKI Flashcards
AKI
An abrupt (within 48 hours) reduction in kidney function currently defined as:
◦ Absolute increase in Scr of ≥ 0.3mg/dL OR
◦ Increase in Scr ≥ 50%(≥ 1.5 x baseline), within the prior 7 days OR
◦ A reduction in urine output (documented oliguria of< 0.5 ml/kg/hr for > 6 hours)
Drug Induced Hemodynamic AKI
-ACEI/ARB
-Cyclosporine/Tacrolimus
-Diuretics
-NSAIDS/COX II INH
Acute Tubular Necrosis - Nephrotoxins
-Aminoglycosides
-Amph B
-Cisplatin, carboplatin
-Cyclophosphamide
-Ifosfamide
-Pentamidine
-Radiocontrast media
-Vancomycin
PRIV CACA
Acute Interstitial Nephritis - Nephrotoxins
-NSAIDS
-Quinolones
-Penicillins
-Sulfonamides
-Rifampin, vanco
Obstructive Nephropathy
- Acyclovir
- Allopurinol
- Indinavir
- Nelfinavir
- Methotrexate
- Quinolones
- Sulfonamides
- Triamterene
Goals of Therapy
- Prevent AKI if possible
- Reduce morbidity (progression to ESRD) and mortality
- Avoid or minimize further insults
- Provide supportive treatment of AKI
- Return of kidney function to baseline
Volume Status
- Hydration
-Sodium chloride or sodium bicarbonate preferred (help renal blood flow)
-Sodium loading beneficial
-Prevent overload
NaCl 0.9% 1L over 2 hr
Vasopressors
For hemodynamic AKI
-only if pt is resuscitated
-norepinephrine, dopamine, vasopressin
-low dose dopamine <= 2 mcg/kg/min
Loop Diuretics
Reserved for volume overload
-convert oliguric AKI to non-oliguric AKI
-patients who are volume overloaded and respond to initial dose of loop diuretic
-but increased mortality in ICU pts with AKI
Indications for Acute Dialysis
-Acidosis (ph<7.1)
-Electrolytes (K>6.5)
-Intoxication (overdose)
-Overload (edema, weight gain, pulmonary congestion)
-Uremia (pericarditis, mental status, neuropathy)
Intermittent Hemodialysis (IHD)
- Patients with hemodynamic stability
- Overdose cases
- Hyperkalemia
Continuous Renal Replacement Therapies (CRRT)
- Hemodynamic instability
- ICU patients are catabolic, better control of uremia
- Excessive volume overload
- Sepsis, SIRS (?)
Dialysis Prescription: IHD
Dialysis Prescription: CRRT
Types of CRRT: CVVH
- Continuous venovenous hemodiafiltration
- Convective and diffusive clearance
- Dialysate and replacement solutions (20 L)
- Blood flow maintained by pump
Determinants of Drug Removal by Dialysis
- Protein Binding
- Volume of Distribution
- Molecular Weight
- Drug Charge?
- Type of modality
- Effluent flow rate
- Blood flow rate
- Fluid replacement (pre/post)
- Hemofilter
Protein Binding
Drugs with a high degree of protein binding (>90%) are less likely to be removed by dialysis
-most important determinant of drug removal by hemodialysis or CRRT
Volume of Distribution
Drugs with small Vd
(< 0.3 L/kg)are located in the intravascular space and more
likely to be removed by dialysis
Drugs with large Vd (> 1 L/kg) are likely distributed at other tissue sites
Molecular Weight
- Most drugs have a MW < 1500 daltons (1 Da=1 g/mol)
- MW is not a major determinant of removal since new hemofilters have large pore size
____ Doses of Fluconazole are Needed in CRRT
HIGHER
Dose Adjustments for Patients with AKI
-IV drugs to bypass absorption issues
Adjust the loading dose of hydrophilic drugs to account for increased Vd
-If Vd doubles, double loading dose
-but reduce once Vd decreases
Etiology
HEMO
-Volume depletion, decreased circulating volume, hypotension, shock, renal vascular occlusion, AA constrictors, EA dilators
INTRINSIC
-Glomerular disorders, acute tubular necrosis, interstitial nephritis (GIT)
OBS
-Nephrolithiasis, BPH, pregnancy, cancer (PBNC)
