Renal and Coagulation Flashcards
What are some basic renal questions you ask?
Have you ever had any kidney problem?
Have you ever had kidney failure, dialysis, or more than two kidney infections?
Have you ever had kidney stones?
Are you undergoing dialysis for kidney problems?
Have you had changes in bowel or bladder function in the last year?
Has your appetite for food changed in the last year? (Voluntary avoidance of foods having a high protein content is a subtle sign of renal disease.)
Dialysis will be required in the following situations:
Oliguria Fluid overload Hyperkalemia Severe acidosis Metabolic encephalopathy Pericarditis Coagulopathy Refractory GI symptoms Drug toxicity
When should dialysis occur, and what should you note?
Optimization, optimization, optimization!
Dialysis should occur day of surgery or day before surgery
Review dialysis flowsheet if available
Amount of fluid “taken off”
Pre and post dialysis weights compare with day of surgery weight
Note POST dialysis chemistry! Serum K < 5.5 mEq/L
What meds get cleared by dialysis and whens should drugs be given?
General rule: scheduled doses of drugs are administered after dialysis
Low-molecular weight, water soluble, non protein bound drugs are readily cleared by dialysis
What are neurological s/s of renal failure?
Uremic Encephalopathy Asterixis Myoclonus Lethargy Confusion Seizures Coma Autonomic Neuropathy Peripheral Neuropathy
What should you look for s/p dialysis?
Disequilibrium syndrome (dialysis related) transient CNS disturbance after rapid decrease in ECF osmolality compared with ICF osmolality Dementia
Hematological assessment?
Anemia typical Hgb = 6-8 g/dL
Decreased erythropoietin production
Decreased RBC production & cell life span
GI blood loss, hemodilution, bone marrow suppression
Excess PTH replaces bone marrow with fibrous tissue
Most patients tolerate the anemia well (exception CAD)
Increased 2,3- DPG (diphosphoglycerate)
Metabolic acidosis also favors rightward shift
What happens with platelets, WBC, dialysis?
Impaired platelets (qualitative) – prolonged bleeding time
Decreased plt factor III activity
Decreased adhesiveness & aggregation
Impaired WBC function – infections
Release of defective von Willebrand factor
Dialysis = Residual anticoagulation VS promotion of hypercoagulable state
Hypocomplementemia with dialysis
Cardiovascular effects?
↑ Cardiac output
compensation for ↓ O2 carrying capacity
HTN – Na retention, renin-angiotensin activation
Left ventricular hypertrophy common
CHF with pulmonary edema after limits of compensation reached
Deposition of calcium - in the conduction system & on the heart valves
Arrhythmias – electrolyte imbalances
Uremic pericarditis – can be asymptomatic, chest pain, tamponade, usually secondary to inadequate dialysis
Accelerated CAD, PVD
Fluid balance effects
Fluid overload VS intravascular depletion status post dialysis/ aggressive diuretic therapy
Body weight
VS (orthostatic hypotension & tachycardia)
Atrial filling pressures
Pulmonary effects?
Minute ventilation increased to compensate for metabolic acidosis
Increased pulmonary extravascular water= interstitial edema = widened alveolar/arterial O2 gradient
“Butterfly wings” on CXR secondary to increased permeability of alveolar capillary membrane (edema even with nml pulmonary capillary pressures)
Endocrine effects?
Peripheral resistance to insulin = poor glucose tolerance
Hyperparathyroidism = prone to fractures
Abnormal lipid metabolism = accelerated atherosclerosis
Kidneys do not degrade hormones and proteins normally = increased circulating PTH, insulin, glucagon, GH, LH, PL
Gi/Liver effects?
10-30% of patients will develop GI Hemorrhage
Anorexia
Nausea and Vomiting
Hypersecretion of gastric acid + delayed gastric emptying (autonomic neuropathy)
High incidence of Hep B and C in these pts (multiple transfusions, etc.)
Ascites with dialysis
IMPACT ON DRUGS, and what drugs are contraindicated?
Effects altered due to: Anemia Decreased serum protein Electrolyte abnormalities Fluid retention Abnormal cell membrane activity Drugs ELIMINATED BY KIDNEYS UNCHANGED are CONTRAINDICATED Gallamine, phenobarbital, LMWH
What renal function tests reflect GFR?
Blood Urea Nitrogen (10-20 mg/dl) Plasma Creatinine (0.7-1.5 mg/dl) Creatinine Clearance (110-150 ml/min)
What renal function tests reflect renal tubular function?
Renal Tubular Function
Urine Specific Gravity (1.003-1.030)
Urine Osmolarity (38-140 mOsm/L)
What is normal BUN and what are high levels indicative of?
BUN normal = 10-20 mg/dL
Varies inversely w/GFR & directly w/protein catabolism
>50mg/dl is indicative of a ↓ GFR (in patients with nml diets)
BUN is not a sensitive index b/c urea clearance also depends on the production of urea
BUN can be abnormal despite a normal GFR due to:
High protein diet
GI bleed
Febrile illness
The most common cause of BUN is CHF secondary to the reabsorption of BUN
