Renal: ESRD Flashcards
Most common treatment used for ESRD?
Hemodialysis
Primary cause of ESRD?
DM
Overall mortality rate of dialysis?
13%, decreasing since 1988
Dialysis life expectancy is…
20-25% of a healthy individual
1 killer of patients on dialysis is…
ASCVD
infections 2nd most common cause
When do you start dialysis?
planning once eGFR or ClCr <30ml/min
benefits and risks of actual start should be eval when eGFR or ClCr <15 ml/min (when to start within next short period of time)
Criteria for starting dialysis
1 = pts clinical status (Persistent anorexia, N/V, weight-loss, fatigue, low serum albumin lvls, neurologic deficits or itching
- concomitant diseases (uncontrolled HTN/CHF)
- Adv/Disadvantages of HD and PD
How often is and how long is each HD session
3/week for about 3-5hrs
larger pts will require long treatment time
What is Dialysate solution?
Purified water and electrolytes
What is important to add with HD?
Add heparin to prevent clotting of blood running through the lines
Two options for access in Hemodialysis
Arterial venus fistula
Synthetic AV graft
Arterial Venus Fistula
Take artery and connect with vein
takes like 6 months before you can use it
Primary Artery used for AV fistula
usually radial or cephalic in forearm
start closer in wrist, if issue can move farther back up
Central venous catheters
are temporary and have a high rate of infection
placed in femoral, subclavian or internal jugular vein
Pro/Con of Native AV fistula
Pro:
- longest access survival
- lowest rate of complications
- inc survival = decrease hospitalizations
- most cost-effective
Con:
- require 1-2 months to mature before use
- difficult to rate in some pt…(elderly, PVD, anyone with Vascular disease)
Pro/Con of Synthetic AV graft
Pro:
1. 2-3 wks to mature
Con:
- shorter survival vs fistula
- increased infections/thrombosis
Pro/Con of Central Venous Catheter
Pro:
- used immediately
- pts like small kids, severe PVD, morbidly obese
Con:
- short life span
- most infections/thrombosis
- mayn’t provide adequate blood flow for dialysis
Diffusion
movement of substances along a conc gradient
Rate depends on conc difference between blood and dialystate, solute characteristics, dialyzer membrane comp and flow rates
Ultrafiltration
movement of water across dialyzer membrane due to hydrostatic or osmotic pressure
primary means for removal of excess body water
Convection
dissolved solutes “dragged” across membrane with fluid transport (during ultrafiltration)
HD membranes: conventional/standard
small pores
limit clearance to smaller molecules
HD membranes: High efficiency
large surface area
can remove water/urea/other small molecules
HD membranes: High Flux
Large pores
capable of removing high-molecular-weight substances
drugs like vancomycin
Shorter treatment times occur with which membranes?
High efficiency and High flux due to increased clearance
Flow rates required for High efficiency/flux membranes
> 400 mL/min blood flow
500 mL/min dialysate flow
can increase risk of hypotension and muscle cramps
Pro/Con of HD
Pro:
- higher solute clearance = intermittent sessions
- Technique failure rate low
- closer pt monitoring
Con:
- Multiple visits/wk to HD center
- SE = Hypotension, muscle cramp, disequilibrium
- Infections
- Vascular thrombosis
Complications during HD
Hypotension
Muscle cramps
Point of Air detector in HD?
To prevent embolism if air is in the lines
can you still urinate on dialysis?
Yes they can
you want to maintain any kidney functions they have as it can improve their outcomes
What causes Hypotension in HD
taking out too much fluid too fast
more common in DM and elderly
What causes muscle cramps in HD
excessive ultrafiltration = decreased plasma volume and decrease muscle filtration
pulls volume out of tissues into vasculature
Acute Hypotension during Dialysis treatment
- Trendelenburg postion
- decrease ultrafiltration rate
- 100-200ml bolus normal saline
- 10-20 ml hypertonic saline bolus
Prevention of Hypotension during Dialysis treatment
Midodrine = 1st choice
2.5-10mg 30min prior to start
Acute Muscle Cramp during Dialysis treatment
- 100-200ml normal saline bolus
2. 10-20ml hypertonic saline bolus
Prevention of Muscle cramp during Dialysis treatment
- Vit E 400IU daily = 1st choice (well tolerated, cheap, easy)
- Quinine
What to do if thrombosis occurs during HD?
give alteplase/reteplase
How to treat infections from HD
- remove catheter
2. give ABX depending on infection based on what it is
Who gets Peritoneal Dialysis
- Hemodynamically unstable
- Sig residual kidney function
- Pts who desire to maintain sig degree of self care as long as they can be trained
PD vs HD
- PD is much less efficient
- No easy method to regulate blood flow
- No countercurrent of flow
PD session will be much longer than HD session
Pros/Cons of Peritoneal Dialysis
Pro:
- More hemodynamic stability vs HD
- Better preservation of residual renal function
- Can admin some drugs IP
- Freedom from HD machine
- Less blood loss/iron deficiency
Con:
- Peritonitis
- Catheter malfunction
- Infection
- Inadequate dialysis and ultrafiltration
- High rate of tech failure
How to treat PD Peritonitis
give ABX intraperitoneally
Prophylaxis of Peritonitis in PD pts
Test for Staph aureus in nose = increase risk
Can give mupirocin intranasal BID/5 days/month
Place daily on exit port
Continuous Renal Replacement Therapies
Used in acute renal failure by toxic substance
CVVH primary clearance is through…
convection
CVVHD primary clearance is through….
Diffusion
CVVHDF primary clearance is through….
Convection and diffusion
Pros/Cons of CRRT vs IHD
Pro:
- Less BP issues
- increase solute removal/day
- improved survival
- faster ARF resolution
Cons:
- increase thrombosis
- Special equip
- intensive RN care & $$$, pharmacy care
- Little known about drug dosing in CRRTs
- ?? nutrition requirement changes
Drug dosing in Dialysis
- If drug dialyzable, schedule admin after dialysis to avoid supplemental dosing
- if in doubt, drug drug levels. need pre/post dialysis levels
Efficiency of drug removal determined by….
- Membrane characteristics
- Dialysis characteristics (Blood flow, duration of dialysis, Dialysate flow rate & composition)
- Drug characteristics (MW, water solubility, protein binding = most important, Volume of Distribution = the higher it is, the lower removed by dialysis)
Small MW of drug influenced by….
Diffusion
Large MW of drug influenced by….
Convection
Volume of Distribution effect on dialysis drug removal
The higher the volume of distribution = the less is removed by dialysis
