Continuous renal replacement therapy (CRRT) provides continuous dialysis treatment for patients with acute renal failure who cannot tolerate traditional intermittent hemodialysis. CRRT works around the clock to provide stable therapy without dangerous electrolyte and hemodynamic changes. There are various CRRT methods that differ in complexity, including continuous venovenous hemodialysis (CVVHD) where blood is pumped through a hemofilter to remove waste and fluids. CRRT requires vascular access via a catheter and uses pumps, hemofilters, replacement fluids, and dialysate to continuously clean and filter the blood. Nursing responsibilities for CRRT include monitoring vitals, equipment, lines, medications, schedules, and managing complications.

1. DIALYSIS
ALBERT BLESSON V

2. DIALYSIS
Continuous Renal Replacement Therapy CRRT
is used to treat patients with ARF. Unlike the more traditional intermittent hemodialysis (IHD), CRRT is
administered around the clock, providing patients with continuous therapy and sparing them the destabilizing hemodynamic
and electrolyte changes characteristic of IHD. It is used for patients, such as those who have hypotension, who cannot tolerate
traditional hemodialysis. For such patients, CRRT is usually the only choice of treatment; however, it can also be used in those
who can tolerate IHD. CRRT methods vary in complexity and include:
In continuous venovenous hemodialysis (CVVHD), a double-lumen catheter provides access to a vein, and a pump moves
blood through the hemofilter.
Continuous venovenous hemodiafiltration provides simultaneous use of dialysate and replacement fluids and removes smaller
substances.
Continuous venovenous hemofiltration (CVVH)
Continuous arteriovenous hemofiltration (CAVH)
Continuous venovenous hemodialysis (CVVHD)
Continuous arteriovenous hemodialysis (CAVDH)
Continuous ultrafiltration (SCUF) (

3. Hemodialysis
Hemodialysis removes toxic wastes and other impurities from the
blood of a patient with renal failure. In this technique, blood is removed
through a surgically created access site, pumped through a dialyzing unit to
remove toxins, and then returned to the body.
The extracorporeal dialyzer works through a combination of
osmosis, diffusion, and filtration. By extracting byproducts of protein
metabolism—notably urea and uric acid—as well as creatinine and excess
water, hemodialysis helps restore or maintain acid–base and electrolyte
balance and prevent the complications associated with uremia.

4. Continuous Venovenous Hemodialysis Setup
During CVVHD, a pump pulls blood from the patient to the arterial
line. A hemofilter removes water and toxic solutes (ultrafiltrate) from the
blood. Filter replacement fluid is infused into a port on the arterial side; this
same port can be used to infuse heparin. The venous line carries the
replacement fluid, along with purified blood, to the patient. This illustration
shows one of several CVVHD setups.

6. HEMODIALYSIS ACCESS SITES
Hemodialysis requires vascular access. The site and type
of access may vary, depending on the expected duration of
dialysis, the surgeon’s preference, and the patient’s condition.
Subclavian Vein Catheterization
This is a double-lumen, cuffed hemodialysis catheter used for
acute hemodialysis. The blood is pumped from the patient to the
dialyzer using the lumen with the red adapter and from the
dialyzer to the patient using the lumen with the blue adapter.

7. Arteriovenous Fistula
To create a fistula, the surgeon makes an incision into the patient’s wrist or
lower forearm, then a small incision in the side of an artery, and another in the side of a
vein. He sutures the edges of the incisions together to make a common opening 3 to 7
mm long.

8. Arteriovenous Graft
To create a graft, the surgeon makes an incision in the patient’s forearm,
upper arm, or thigh. He then tunnels a natural or synthetic graft under the skin and
sutures the distal end to an artery and the proximal end to a vein

9. HOW HEMODIALYSIS WORKS
• During hemodialysis, blood flows from the patient to an external dialyzer (or artificial kidney) through an arterial
access site. Inside the dialyzer, blood and dialysate flow countercurrently, divided by a semipermeable membrane.
• The dialysate’s composition resembles normal extracellular fluid. The blood contains an excess of specific solutes
(metabolic waste products and some electrolytes), and the dialysate contains electrolytes that may be at abnormal levels in
the patient’s bloodstream.
• The dialysate’s electrolyte composition can be modified to raise or lower electrolyte levels, according to the patient’s
needs. Excretory function and electrolyte homeostasis are achieved by diffusion, the movement of a molecule across the
dialyzer’s semipermeable membrane, from an area of higher solute concentration to an area of lower concentration.
• Water (solvent) crosses the membrane from the blood into the dialysate by ultrafiltration. This process removes excess
water, waste products, and other metabolites through osmotic pressure and hydrostatic pressure.
• Osmotic pressure is the movement of water across the semipermeable membrane from an area of lesser solute
concentration to one of greater solute concentration. Hydrostatic pressure forces water from the blood compartment into the
dialysate compartment. Cleaned of impurities and excess water, the blood returns to the body through a venous site.

10. TYPES OF DIALYZERS
There are three types of dialyzers: the hollow-fiber, the flat-plate or parallel flow-plate, and the coil.
The hollow-fiber dialyzer, the most commonly used dialyzer, contains fine capillaries, with a semipermeable
membrane enclosed in a plastic cylinder. Blood flows through these capillaries as the system pumps dialysate in the opposite
direction on the outside of the capillaries.

11. The flat-plate or parallel flow-plate dialyzer is not widely used but has two or more layers of semipermeable
membranes, bound by a semirigid or rigid structure. Blood ports are located at both ends, between the membranes. Blood
flows between the membranes, and dialysate flows in the opposite direction along the outside of the membranes.

12. The coil dialyzer (no longer widely used) consists of one or more semipermeable membrane tubes supported by
mesh and wrapped concentrically around a central core. Blood passes through the coils as dialysate circulates at high speed
around the coils and meshwork

13. The flat-plate and hollow-fiber dialyzers may be used several times on each patient. Heparin is
given to prevent clot formation during hemodialysis.
Three system types can be used to deliver dialysate. The batch system uses a reservoir for recirculating
dialysate. The regenerative system uses sorbents to purify and regenerate recirculating dialysate. The proportioning
system (the most common) mixes concentrate with water to form dialysate, which then circulates through the dialyzer
and goes down a drain after a single pass, followed by fresh dialysate

14. PERITONEAL DIALYSIS
Like hemodialysis, peritoneal dialysis removes toxins from the blood of a patient with
acute or CRF that does not respond to other treatments. Unlike hemodialysis, it uses the
patient’s peritoneal membrane as a semipermeable dialyzing membrane. With this technique, a
hypertonic dialyzing solution (dialysate) is instilled through a catheter inserted into the
peritoneal cavity. Then by diffusion, excess concentrations of electrolytes and uremic toxins in
the blood move across the peritoneal membrane into the dialysis solution. Next, through
osmosis, excess water in the blood does the same. After appropriate dwelling time, the
dialysate is drained, taking toxins and wastes with it

15. PRINCIPLES OF PERITONEAL DIALYSIS
Peritoneal dialysis works through a combination of diffusion and osmosis
.DIFFUSION In diffusion, particles move through a semipermeable membrane from an area of high-solute
concentration to an area of low-solute concentration.In peritoneal dialysis, the water-based dialysate being infused
contains glucose, sodium chloride, calcium, magnesium, acetate or lactate, and no waste products. Therefore, the
waste products and excess electrolytes in the blood cross through the semipermeable peritoneal membrane into
the dialysate. Removing the waste-filled dialysate and replacing it with fresh solution keeps the waste
concentration low and encourages further diffusion.
OSMOSIS In osmosis, fluids move through a semipermeable membrane from an area of low-solute concentration
to an area of high-solute concentration. In peritoneal dialysis, dextrose is added to the dialysate to give it a higher
solute concentration than the blood, creating a high osmotic gradient. Water migrates from the blood through the
membrane at the beginning of each infusion, when the osmotic gradient is highest

16. COMPARING PERITONEAL DIALYSIS CATHETERS
The first step in any type of peritoneal dialysis is the insertion of a catheter to allow instillation of a dialyzing
solution. The surgeon may insert one of three different catheters described here.
TENCKHOFF CATHETER
To implant a Tenckhoff catheter, the surgeon inserts the first 6 3/4′′ (17 cm) of the catheter into the
patient’s abdomen. The next 2 3/4′′ (7 cm) segment, which may have a Dacron cuff at one or both ends, is imbedded
subcutaneously. Within a few days after insertion, the patient’s tissues grow around the cuffs, forming a tight barrier against
bacterial infiltration. The remaining 3 7/8′′ (10 cm) of the catheter extends outside of the abdomen and is equipped with a
plastic adapter at the tip that connects to dialyzer tubing.

17. FLANGED-COLLAR CATHETER
To insert this type of catheter, the surgeon positions its flanged collar just below
the dermis so that the device extends through the abdominal wall. He keeps the cuff’s
distal end from extending into the peritoneum, where it could cause adhesions.

18. COLUMN-DISK PERITONEAL CATHETER
To insert a column-disk peritoneal catheter (CDPC), the surgeon rolls up the flexible disk section of the
implant, inserts it into the peritoneal cavity, and retracts it against the abdominal wall. The implant’s first cuff rests
just outside the peritoneal membrane, while its second cuff rests just underneath the skin. Because the CDPC does
not float freely in the peritoneal cavity, it keeps inflowing dialyzing solution from being directed at the sensitive
organs, which increases patient comfort during dialysis

19. Nursing responsibilities
• Weight
• Vital signs
• Arterial and venous pressure
• Dialyser and types
• Arterial and venous line
• Heparin
• Bicarb and acetic
• Timings
• Vaccination
• Anemic management
• Complication management
• Sterile procedure
• Pump speed
• Schedule for patient
• Intradalytic exercise
• AV fistua / central line
• Fluid management
• Priming the tubing /before
starting
• Emergency management
• Electrolytes level
• Pain
• UFR

20. THANK YOU
REFERANCE
LippincottVISUAL NURSING
A Guide to Diseases, Skills, and
Treatments
Third Edition