Renal AKI & CKD Flashcards
(43 cards)
What is Acute Kidney Injury (AKI)?
The deterioration of renal function over hours to days.
-Dec GFR, so not excreting nitrogenous substances and wastes
-Accumulation of Creatinine and urea in blood
-Dec Urine production
-ATN is most common cause in surgical patients.
-Can be prerenal (Hypoperfusion, obstructive uropathy)
-Mortality < 10% unless in critical illness or MSOF
What are exogenous nephrotoxins?
-Antibiotics (additive effect with other factors)
-Anesthetic agents (Enflurane, Keep Sevo to under 2 MAC hours)
-NSAIDs
-Chemotherapeutic agents (additive effect with other factors)
-Contrast
Who is at increased risk of AKI from Radiocontrast Dye?
-Threat to patients with diabetic nephropathy, renal vasoconstriction and renal insufficiency
-May take 24-48 hours to develop and peak at 3-5 days
What are endogenous nephrotoxins?
-Inc Calcium
-Uric acid
-Myoglobin (Rhabdo)
-Hemoglobin(hemolysis)
-Bilirubin
-Paraproteins
What is Prerenal Azotemia?
High levels of nitrogen compounds such as Urea, Creatinine, etc.
-Reversible if underlying cause is corrected
-Elderly are susceptible due to hypovolemia and renovascular disease
-Inc risk occurs with CHF, Liver dysfunction, and Septic Shock
-May need invasive monitoring to assess intravascular status
What are the causes of Prerenal Acute Renal Failure (decreased RBF)?
Absolute Decreases:
-Acute hemorrhage
-GI fluid loss
-Trauma
-Surgery
-Burns
Low Output Syndromes:
-Renal artery stenosis
-Relative decrease
-Sepsis
-Hepatic failure
-Allergic reaction
Describe Renal Azotemia?
Occurs when the functional unit of the kidney is injured.
-Categorized according to site of injury
-Renal tubules -> ischemia and nephrotoxins
-Can reverse if underlying cause is corrected.
-Irreversible if ischemia is severe or prolonged.
-Acute interstitial nephritis (allergic drug rxn)
What are the etiologies of Renal Acute Renal Failure?
Acute glomerulonephritis
Vasculitis
Interstitial nephritis (drug allergy, infiltrative diseases)
What are the causes of Acute Tubular Necrosis?
Ischemia
Nephrotoxic drugs (aminoglycosides, nonsteroidal anti-inflammatory drugs)
Solvents (carbon tetrachloride, ethylene glycol)
Heavy metals (mercury, cisplatin)
Radiographic contrast dyes
Myoglobinuria
Intratubular crystals (uric acid, oxalate)
What are the causes of Post Renal Acute Renal Failure?
Urinary outflow tracts obstructed:
-Prostatic hypertrophy or cancer of prostate or cervix
-Bladder carcinoma
-Clot retention or nephrolithiasis
Needs quick diagnosis: Potential for recovery inversely related to duration of obstruction
Treatment: Percutaneous Nephrostomy
What are risk factors for Acute Renal Failure (ARF)?
-Co-existing renal dz
-CHF
-Advanced age
-Symptomatic CV disease
-Major operative procedures (CPB, AAA repair)
-Sepsis
-Multi-organ system failure
-Iatrogenic: inadequate fluid volume replacement, delayed tx of sepsis, nephrotoxic drugs or dyes
What are risk factors for Perioperative Renal Failure?
Pre-existing Renal insufficiency
Shock
High-risk Surgical Procedures
Nephrotoxin Use
What are examples of pre-existing renal insufficiency that increases risk for periop renal failure?
Congestive heart failure
Diabetic nephropathy
Hypertensive nephropathy
Liver failure
Pregnancy-induced hypertension
What are high-risk surgical procedures that increase risk for periop renal failure?
Renal vascularization
Aortic cross-clamping
Cardiopulmonary bypass
Urologic surgery
Transplantation
Trauma
What are Nephrotoxins that increase risk for periop renal failure?
Aminoglycoside antibiotics
Radiocontrast dyes
Nonsteroidal anti-inflammatory drugs
What are the Neuro complications of ARF?
Confusion
Asterixis
Somnolence
Seizures
What are the CV complications of ARF?
Systemic HTN
CHF
Pulmonary Edema
Cardiac Dysrhythmias
May have dilutional anemia
Potential for CV Collapse
What are the GI complications of ARF?
Anorexia
Nausea
Vomiting
Ileus
GI Bleeding
What are the S/Sx of ARF?
Generalized Malaise ->
Volume Overload (Dyspnea, edema, HTN) -> Lethargic, Nauseated, confused -> Pulmonary edema, hypoxia, hyperkalemia, acidosis -> Encephalopathy (coma, seizures, death)
By the time of symptom onset, significant kidney injury is occurring
What is the anesthetic management for ARF?
-Fluid Resuscitation: Colloids or crystalloids (NS) acceptable. Keep MAP > 80 mmHg
-Vasopressors: concern with increased renal vasoconstriction
-Dopamine: not supported by literature to treat/prevent ARF. Do have Dopamine receptors in the nephron. Fenoldopam is better (D1 agonist)
-Mannitol: Improves renal outcomes
-Invasive monitoring: BP and frequent blood gases
-Only life saving surgery
Which drugs do you increase the interval in the presence of renal failure?
Acetaminophen
Acetylsalicyclic Acid
Which drugs do you decrease the dose of in the presence of renal failure?
Codeine
Fentanyl
Ketorolac
Meperidine
Methadone
Morphine
What do you do to the dose of Al/Remi/Sufentanil in the presence of renal failure?
No change in dose (? is this right?)
What is Chronic Renal Failure?
Progressive, irreversible deterioration of renal function
-Result of a wide variety of diseases. #1 Diabetes #2 HTN
-Manifests as overall inability of kidney to excrete waste products, regulate fluid and electrolyte balance and secrete hormones
