acute renal failure1
TRANSCRIPT
ACUTE RENAL FAILURE
Trish Keresztes, PhD, RN, CCRN
ARF: REVIEW RENAL FUNCTION
Regulate fluid volume. Regulate electrolyte balance. Regulate acid-base balance. Regulate blood pressure. Excrete nitrogenous waste products. Produce erythropoietin. Metabolism of vitamin D.
ACUTE RENAL FAILURE
Precipitous and significant (>50%) decrease in glomerular filtration rate (GFR) over a period of hours to days with an accompanying accumulation of nitrogenous wastes in the body.
ACUTE RENAL FAILURE
Glomerulus: tuft of capillaries. The wall of the glomerular capillary serves as a filtration membrane with three layers– Inner capillary endothelium– Middle basement membrane– Outer layer of capillary epithelium
ACUTE RENAL FAILURE
The glomerular filtrate passes through the three layers of the glomerular membrane and forms the primary urine.
GFR: the filtration of the plasma per unit of time. Directly related to the perfusion pressure in the glomerular capillaries.
ACUTE RENAL FAILURE
Process of urine formation:– Glomerular filtration-> tubular reabsorption-
>tubular secetion->excretion.– Proximal tubules reabsorbs 60-70%
sodium and water and 90% other electrolytes.
– Distal tubules reabsorb sodium, secrete potassium and hydrogen ions (regulate acid base balance.
ACUTE RENAL FAILURE
ACUTE RENAL FAILURE
ACUTE RENAL FAILURE
ARF: RISKS FOR DEVELOPMENT
Hx DM, HTN, CV disease, calculi. Family history calculi, HTN. Hypotensive episodes. Drugs with potential for nephrotoxicity. Major trauma, crushing injuries, severe
allergic reactions.
Acute Renal Failure
Occurs in 4% of all hospital admissions. Occurs in 20% of those admitted into
critical care units. Mortality rate 50% overall. Mortality rate for hospital acquired ARF
is 70%.
Pathophysiology
Glomerular pressure is primarily dependant upon renal blood flow.
Depressed renal blood flow eventually leads to ischemia and tubular cell death.
As tubular cells die, they slough off into the tubules and form obstructing casts which further decrease GFR and lead to oliguria.
ACUTE RENAL FAILURE
Azotemia: refers to an abnormally high level of nitrogenous wastes (urea nitrogen, uric acid, creatinine) in the blood related to a decrease in the GFR.
Uremia: a clinical syndrome that comprises the signs and symptoms associated with end stage renal disease.
ARF CAUSES
Prerenal: decreased blood flow to the kidney.
Intrarenal: Direct damage to the kidney parenchyma.
Postrenal: Obstruction to the flow of urine which may cause hyronephrosis.
Before-within-after the kidney.
ARFPRERENAL CAUSES
Inadequate intravascular volume:hypovolemia– Fluid loss from N/V– Hemorrhage– Excessive diuresis
Redistribution of blood volume– Peripheral vasodilation with sepsis– Third spacing
ARFPRERENAL CAUSES
Reduced cardiac output– Acute MI -> cardiogenic shock– CHF– Cardiac tamponade
Renal artery thrombosis Interruption of blood flow during surgery
ARFINTRARENAL CAUSES
Acute Tubular Necrosis most common form ATN: Prolonged ischemic damage: MAP <60
for 40 minutes Nephrotoxic damage
– Radiographic contrast dye– Drugs: antibiotics (aminoglycosides), NSAIDS– Heavy metals (lead, mercury)
Glomerulonephritis
ARFINTRARENAL CAUSES
Rhabdomyolysis: breakdown of skeletal muscle
Blood transfusion reactions Pesticides Lupus
ARFPOSTRENAL CAUSES
Obstruction due to– Calculi– Blood clots– BPH– Obstruction of indwelling catheter– Tumors
ARFFOUR PHASES
Onset Oliguria (U/O <400ml/day) Diuresis Period of recovery
ARF ONSET
Begins with insult and ends with oliguria Associated with decreased renal blood flow
and GFR and decreased cardiac output. The key is prevention Monitor blood pressure Monitor volume status Monitor cardiac function Monitor labs Identify potential nephotoxins
ARF OLIGURIC PHASE
Obstruction of tubules by cellular debris, tubular casts or tissue swelling.
Total reabsorption of urine filtrate back into circulation.
Renal vasoconstriction ensues.
ARF OLIGURIC PHASE
Can last up to 8 weeks. The longer this phase the poorer the prognosis.
See a volume overloaded patient. Lab values altered. Acidosis. Diet changes. May treat with low dose dopamine.
ARF DIURESIS PHASE
See an increase in urine output. Urine output as much as 1L/hr. Creatinine clearance 15ml/min. Signifies tubular function is returning. Need to monitor volume status-FVD. What happens to lab values during this
phase? What are your concerns?
ARF RECOVERY PHASE
Lasts about six months. ATN irreversible in about 55% of
patients. GFR returns to 70% to 80% of normal
within 1-2 years.
ARF SIGNS AND SYMPTOMS
CNS: lethargy, confusion, tremors, seizures, coma
CV: EKG changes, tachycardia, edema PULM: SOB, rales, frothy sputum with CHF,
rapid respirations (Kussmaul’s) GI: N/V/D GU: urine scant, cloudy, sediment Integ: dry skin, edema, pallor, uremic frost,
pruritis
ARF LABORATORY DATA
BUN Normal BUN:Cr ration is 10:1. If excess in ration of 20:1 suspect dehydration, catabolic state.
Creatinine– Creatinine 1.0 mg/dl: normal GFR– Creatinine 2.0mg/dl: 50% reduction GFR– Creatinine 4.0mg/dl: 70-85% reduction GFR– Creatinine 8.0mg/dl: 90-95% reduction GFR
ARF LABORATORY DATA
Creatinine Clearance– Determines presence and progression of
renal disease.– Estimation of % of functioning nephrons.– Determine medication dosages.
– Calculation= Ucr x V/Pcr
ARF LABORATORY DATA
ABGs Potassium Phosphorus Calcium RBC, HGB
ARF TREATMENT
Correct cause Manage volume status. Correct electrolyte imbalances. Correct acidosis. Treat azotemia: dialysis. Nutritional requirements. Stimulate kidneys: drugs.
ARF HYPERKALEMIA
Kayexalate enema, po Sorbitol retention enema D50W with Humulin R insulin Sodium Bicarbonate IV IV calcium gluconate Dialysis
ARF DIETARY CHANGES
Restrict protein High CHO, fat Restrict fluids Restrict sodium Restrict potassium
ARF MEDICATIONS
Diuretics: lasix, bumex, mannitol Aluminum hydroxide preparations: Calcium replacement Epogen/ iron supplements
ARF: Complications
GI Bleed: occurs in 1/3 of patients with ARF. Accounts for 3% to 8% deaths in patients with ARF.
Pulmonary complications Pericarditis Infections: 33% of patients. Usually
pulmonary or urinary Jaundice
ARF CASE STUDY
61 y/o male admitted to the ER with N/V, abd. pain, general malaise, s/w lethargic, resp’s deep and rapid T99.6, P106 R 32, BP 156/92 +1 edema to mid calves, states he’s not been eating or drinking too much and that he’s had the flu x1 wk. At home meds maxide ?mg. for “blood pressure” and has been taking “a lot” of motrin for aches with the flu
ARF CASE STUDY
LABS: Na 135, K 5.0, Bun 70, Cr 4.3 Ca 8.3, Phos 4.9, H&H 10 &35
ABG pO2 98, pCO2 29,pH 7.30, HCO3 20
What is your impression and why? Identify ALL factors that made you think
of ARF. What phase and what cause?
HEMODIALYSIS
Indications for use:– Acute renal failure– Chronic renal failure– Remove potassium– Remove drugs from overdose– Remove fluids
HEMODIALYSIS
Diffusion: movement of solutes across a semipermeable membrane from an area of higher concentration to lower concentration. Urea, creatinine, potassium.
Osmosis: passage of a solvent or water from area of lesser solute concentration to area of greater solute concentration.
HEMODIALYSIS
Components of hemodialysis– Dialyzer – Dialysate– Vascular access– Hemodialysis machine– Anticoagulation during dialysis
HEMODIALYSISCOMPLICATIONS
Hypotension (need 350cc blood to prime tubing)
Bleeding Infection Heart failure Arrhythmias from hypoxia, hypokalemia
HEMODIALYSISVASCULAR ACCESS
Permanent vascular access AV fistula AV graft tubing Dual lumen Complications: thrombus, infection,
aneurysm formation, ischemia
HEMODIALYSISVASCULAR ACCESS
Temporary access Used for short term dialysis or bridge
until permanent access is available Placed in subclavian, jugular, femoral
veins.
NURSING CAREAV FISTULA/GRAFT
DO NOT take blood pressure in the extremity with the fistula/graft.
DO NOT perform venipunctures in the extremity with the fistula/graft. No IVs.
DO palpate for thrills and auscultate bruits over access.
DO assess for pulses in extremity.
NURSING CAREAV FISTULA/GRAFT
DO elevate extremity. DO check site for bleeding and
infection. DO NOT allow patient to wear tight
clothing or jewelry on extremity. DO NOT let patient sleep on extremity. DO NOT let patient carry heavy objects.
VASCULAR ACCESS
Complications– Infection– Bleeding– Clotting
PERITONEAL DIALYSIS
Good for patient that cannot tolerate HD due to hemodynamic instability, inability to tolerate anticoagulants, and those without venous access
Utilizes principles of diffusion & osmosis
TYPES OF PD
CAPD-continuous ambulatory peritoneal dialysis
MB-CAPD- multiple bag Automated PD IPD-intermittent PD CCPD-continuous cycle PD
Steps of CAPD treatment
Inflow-full bag in (10 minutes) Cloudy outflow Dwell-remains in the abdomen 4-8 hrs Outflow-let gravity drain fluid out (15
minutes) Inflow- start it over again
PERITONITIS
Cloudy outflow Fever Rebound abdominal tenderness General malaise Nausea Vomiting
NURSING CARE
Stress cleanliness in the home Sterile technique with the catheters Dialysate must be room temperature
(cold=cramps) Diet and fluid restrictions are less with
PD Monitor BP (>with FVE, < with FVD)