RRT Flashcards
Is dialysis acute or chronic
Both
Indications for acute dialysis
- Persistent hyperkalemia
- Fluid overload, hypertension
- Impending pulmonary edema (Fluid overload)
- Increasing metabolic acidosis
- Pericarditis
- Advanced uremia
- Remove toxic meds or overdose
- Edema unresponsive to other treatments
- Hepatic coma, uremic encephalopathy, hypercalcemia
Indications for chronic or maintence dialysis
- Advanced CKD or ESKD
- Uremic signs and symptoms, N+V severe anorexia, increased lethargy, mental confusion
- Hyperkalemia
- Fluid overload not responsive to diuretics and fluid restrictions
Hemodialysis
- Prevents death, not a cure
- Known as artificial kidney
- Can be done intermittently, outpatient, and at home
Intermittent hemodialysis:
3x a week for 3-5 hours
Outpatient dialysis
Dialysis center clinic/hospital
Home dialysis
- Patient and caregiver, treatment time and frequency is flexible
Principles of Hemodialysis
- Diffusion
- Osmosis with ultrafiltration
How does hemodialysis work
- homeostasis/ body’s buffer system is maintained by dialysate bath (Bicarb or acetate)
- Heparin, anticoagulant used to keep blood clotting within the dialysis machine
Goal of hemodialysis
- Cleansed blood returned to the body
- Fluid removal
- Electrolyte balance
- Acid base control, correcting acidosis
Components of hemodialysis
- Dialyzer
- Dialysate/ dialysis bath
- Dialysis machine
- Water treatment
Dialyzer
- Hollow fiber devices containing thousands of tiny capillary tubes that carry the blood through the artificial kidney
- Semi Permeable membranes allow toxins, fluids, electrolytes to pass across the membranes
- Constant flow of solution (Dialysate bath) maintains concentration gradient (Osmosis) to facilitate exchange of waste from blood across from the semipermeable membrane into the dialysate solution where they are removed and discarded
Dialysis: Vascular access
- Known as the lifeline
- Central venous cath (CVC)
- Arteriovenous fistula (AVF)
- Arteriovenous graft (AVG)
Vascular access device: CVC
- Double lumen, large bore (SC, IJ or femoral vein)
- Risks: hematoma, pneumothorax, infection, thrombosis , inadequate flow
- Cath removed when no longer needed, resolved Renal failure or perm access established
Arteriovenous fistula (AVF)
- Created surgically
- Usually in the forearm by joining an artery to a vein
- Needles are inserted into the vessel to obtain blood flow adequate to pass through the dialyzer
- Venous segment dilates due to increased blood flow coming directly from the artery, once dilated it will accommodate 2 large bore needles (14-16 gauge)
- Arterial and venous segment
- Longest useful life and thus the best option for vascular access
Check the presence of a bruit and thrill
AVF: Arterial segment
- Fistula for arterial flow to the dialyzer
AVF: Venous segment
For reinfusion of dialyzed blood
Back to arm
How long does it take for a AVF to establish
- 2-3 mo to establish
Arteriovenous graft (AVG)
- Created by subcutaneously interposing a biologic, semi biologic or synthetic graft material between an artery and vein
- Graft is created when a patients vessels are not suitable for AVF
Check the presence of a bruit and thrill
Complications of a AVG
Stenosis, infection, thrombosis
Complications of hemodialysis
- Hypotension: From fluid removal (N+V, diaphoresis, tachycardia, dizziness)
- Malnutrition
- Bone pain and fractures from poor calcium metabolism and renal osteodystrophy
- Calcification of major blood vessels
- Phosphorus deposits in skin causing itching
- Seizures
- Major sleep issues
- Episodes of SOB often occur as fluid accumulates between dialysis treatments
- Painful muscle cramping , late into dialysis as fluid and electrolytes leave the extracellular space
- Exsanguination: Blood lines separate or dialysis needles become dislodged
- Dysrhythmias from electrolyte and PH changes from removal of antiarrhythmic meds during dialysis
- Air embolism
- Chest pain from anemia or arteriosclerotic heart disease
- Dialysis disequilibrium syndrome