Week 13: Chp 62: Renal Replacement Therapies Flashcards
What are Renal Replacement Therapies (RRTs)?
are artificial processes for removing waste and water from the body when the kidneys are no longer functioning adequately
Renal Replacement Therapy Therapy ecthniques inclue?
- Intermittent hemodialysis (HD)
- continuous renal replacement therapies (CRRTs)
- peritoneal dialysis (PD)
Hemodialysis and Peritoneal dialysis process consists of what?
processes in which blood is separated from a dialysis solution by a semipermeable membrane; hemodialysis uses an artificial membrane; PD uses the peritoneal membrane
-solutes and water move across the membrane by diffusion or movement across a concentration gradient , supported by the addition of dialysate to the circuit, and by filtration, which is the movement of water driven by hydrostatic pressure gradient
What is the process of Continuous renal replacement therapies (CRRTs)
process where blood flows through a filter, and solute and fluid removal is accomplished via filtration, diffusion, or convection–the movement of solutes through the membrane via the force of fluid or water movement
Dialysis is indicated for what patients?
- AKI (acute kidney injury) and ESRD (end-stage renal disease); characterized by:
- presence of severe fluid and electrolyte imbalances
- elevated serum creatinine
- elevated serum potassium levels
- acidosis
- presence of uremic manifestations
- patients with a GFR of less than 10 mL/min
Most common form of renal replacement therapy for ESRD (end-stage renal disease)
-hemodialysis (HD) and peritoneal dialysis (PD)
Where can hemodialysis be performed?
in outpatient centers, inpatient hospital settings, and sometimes in home settings
Where can peritoneal dialysis be performed?
generally in the home
-can receive while hospitalized or as outpatients
Continuous renal replacement therapies (CRRTs) are indicated for?
acutely ill patients
-these therapies manage acid-base balance, electrolyte levels, and fluid balance slowly and continuously in a hemodynamically unstable patient
Hemodialysis Vascular Access
3 types of vascular access
- Intravenous vascular access
- arteriovenous (AV) fistula
- arteriovenous (AV) graft
Intravenous vascular access
may be secured using a central venous double-lumen catheter in the subclavian or internal jugular vein
-usually used for the short term, such as treating a patient with AKI with intermittent HD or when waiting to secure long term access for HD
Arteriovenous (AV) fistula
created by surgical anastomosis of an artery and vein, typically the radial artery and the cephalic vein, in the nondominant arm
- after procedure, the fistula is allowed to mature to become suitable for dialysis; maturing the AV fistula occurs when the low-pressure vein becomes accustomed to the higher pressures generated in the artery which allows adequate blood flow for dialysis
- the “matured” fistula appears large, bulging and tortuous under the skin; can require weeks to months
Arteriovenous (AV) graft
created by inserting a prosthetic graft between an artery and vein, in the nondominant arm
-can be used more quickly than the fistula but does not last as long and is more prone to infection (not preferred method)
A functional AV fistula and AV graft includes what when assessing?
has a palpable pulsation, a thrill, and a bruit on auscultation
Hemodialysis
is a life-sustaining procedure for a patient with AKI or ESRD
- used the process of diffusion and filtration to remove waste products, electrolytes, and excess water from the body
- undergo 3 times a week; 3 to 5 hours for each treatment
Process of Hemodialysis
- Blood is pumped from the body through the vascular access device to a dialyzer
- in the dialyzer, the blood moves past an artificial semi-permeable membrane
- a dialysate solution with similar solute concentration as normal extracellular fluid is warmed to body temperature and pumped along the other side of the membrane
- solute molecule movement across the membrane is determined by a concentration gradient, from an area of higher to lower concentration via diffusion; waste products such as urea and creatinine diffuse across the membrane into the dialysate
- bicarbonate may be added to the dialysate to make corrections for acidosis if present
- negative pressure is maintained on the dialysate side to allow excess fluid removal via hydrostatic pressure, a process known as filtration
- heparin is added to the circuit to prevent clotting
- saline may be added to help prevent clotting and facilitate flow through the dialyzer
- the “cleaned” blood is returned via the vascular access device
Complications of HD
can occur during, or after dialysis
- hypotension due to the rapid removal of fluid from the vascular compartment or vasodilation; may display light-headedness, nausea, vomiting, seizures, vision changes, and chest pain from cardiac ischemia; decrease the rate of fluid removal and replace fluid IV with normal saline
- muscle cramps, headache, nausea, dizziness, and malaise due to rapid removal of electrolytes and water; reducing the filtration rate or infusing a normal saline bolus
- bleeding because of the altered platelet function associated with uremia and the use of heparin during the procedure
- systemic infection is a concern
- dialysis associated dementia is a progressive, potentially incurable neurological complication associated with long-term dialysis; though to be due to aluminum, which is present in the phosphate binders
- dialysis disequilibrium syndrome
- localized AV fistula or graft complications (infection, clotting, or thrombosis)
Peritoneal dialysis
life-sustaining treatment for a patient with ESRD
- offers increased patient control and flexibility with the option of home treatment
- requires a shorter training period for the patient and can be performed independently or by a family member
- involves fewer dietary restrictions and greater mobility
- clearance of metabolic wastes is slower but more continuous
- avoids rapid fluctuations in extracellular fluid composition and associated symptoms
- 3 forms: continuous, automated, and intermittent
Peritoneal dialysis (PD) is indicated for who?
patients who desire more control, who have vascular access problems, or who respond poorly to HD with hemodynamic instability
-older patients and ESRD patients with diabetes may be more easily managed with PD
The process of peritoneal dialysis (PD)
the highly vascular membrane of the peritoneal cavity is used as the dialyzer layer
-fluid and solute removal occurs via diffusion and filtration
-PD process consists of fill, dwell, and drain phases
>fill phase: room temperature, sterile dialysate is instilled into the peritoneal cavity via a permanent indwelling PD catheter, made of silicone rubber tubing, the fluid remains in the abdomen for a predetermined “dwell” time
-metabolic waste products and excess electrolytes diffuse into the dialysate while it remains in the abdomen; water diffusion is controlled using dextrose in the dialysate as an osmotic gradient; gravity then drains the fluid out of the peritoneal cavity into a sterile bag
Contraindications for PD
- history of multiple abdominal surgeries or chronic abdominal conditions such as pancreatitis or diverticulitis
- recurrent abdominal wall or inguinal hernias
- obesity with large abdominal wall
- pre-existing back problems or vertebral disease
- severe chronic obstructive pulmonary disease
Complications in PD
- peritonitis and catheter infections
- abdominal pain
- hyperglycemia and increased triglyceride levels
- outflow problems
- respiratory compromise
- protein loss
Nursing Interventions: Assessment
- vital signs
- oxygenation/respiratory status
- temperature
- daily weight at the same time everyday
- Lab values
- filtrate appearance
- nutritional intake
Assessment: Vital Signs
blood pressure and heart rate are indicators of fluid volume status that are changing during the dialysis procedure
-hypotension may occur with aggressive fluid removal
Assessment: oxygenation/respiratory status
decreased oxygenation may occur with fluid volume overload, with decreased respiratory effort, or during dwell time in PD
-abnormal findings such as gallops, murmurs, rales, SOB, and tachypnea can indicate fluid volume overload
Assessment: temperature
increased temperature is an indication of infection
-all forms of dialysis increase the risk of infection through the presence of multiple IV lines or a PD catheter
Assessment: Filtrate appearance
pink or bloody filtrate in any form of dialysis indicates bleeding
-cloudy filtrate in PD indicates infection
Assess: Coagulation studies; hemoglobin/hematocrit
bleeding risk is higher with all forms of dialysis because of the need for heparinization
Assess: WBC count
infection is a risk for all forms of dialysis
Assess: Electrolyte and renal studies
dialysis produces changes in electrolyte and renal studies, which may require changes in the dialysis procedure or dialysate composition
Assess: nutritional intake
sodium and water restriction may be necessary to optimize dialysis
-protein intake may need to be increased because of protein loss during dialysis
Nursing assessment With Hemodialysis: frequent assessment of bruit or thrill
a patent AV fistula or graft has a palpable pulsation, a thrill, and a bruit or whooshing sound on auscultations caused by the flow of blood
- a normally functioning graft has a low-pitched bruit
- a turbulent bruit is indicative of increased force, mostly due to stenosis
- absence of thrill or bruit is indicative of a nonfunctional AV fistula or graft
Nursing Assessment with Hemodialysis: Neurological assessment
the rapid shift of fluid and substances can create a high osmotic gradient in the brain, resulting in a shift of fluid into the brain causing cerebral edema (dialysis disequilibrium syndrome)
-dialysis related dementia, caused by aluminum in the dialysate or phosphate binders may occur
Nursing Assessment with Hemodialysis: Systems assessment post-dialysis
muscle cramps, headache, nausea, dizziness, and malaise are common during and after dialysis as a result of the rapid removal of electrolytes and water
Nursing Assessments with Hemodialysis
- frequent assessment of bruit/ thrill
- neurological assessment
- system assessment post-dialysis
Nursing Assessment with Peritoneal Dialysis
- abdominal girth; measure the abdominal girth and record in order to make comparisons for future assessments
- monitor outflow; decreased outflow may indicate a kinked or mal-positioned catheter, which may require repositioning of the catheter, turning the patient to the side, or gentle abdominal massage
Nursing Actions for hemodialysis
- avoid any procedures, blood draws, IV insertion, or blood pressure readings in the arm with the HD access; can increase the risk of thrombus formation and infection
- hold medications that may be dialyzed out or cause complications during the procedure until after the HD session; some antibiotics or anticonvulsants may be lost in dialysis. Water-soluble vitamins are also lost during dialysis. Anti-hypertensives or vasoactive medications may cause hemodynamic instability during the procedure and should be held as ordered, especially if the patient is known to be hemodynamically unstable during dialysis
