NKF KDOQI GUIDELINES 2000
GUIDELINES FOR PERITEONAL DIALYSIS ADEQUACY
VIII. Suitable Patients for Peritoneal Dialysis
Indications for PD (Opinion)
Indications for PD include:
Patients who prefer PD or will not do hemodialysis (HD).
Patients who cannot tolerate HD (eg, some patients with congestive or ischemic heart disease, extensive vascular disease, or in whom vascular access is problematic, including the majority of young children).
Patients who prefer home dialysis but have no assistant for HD, or whose assistant cannot be trained for home HD.
Rationale There is a rapid change in solute transport as well as rapid shifting of volume within compartments during HD. Some patients with severe cardiac disease may be better managed on PD since these acute changes are avoided.119-123 PD has been proposed as a method of managing refractory heart failure even in patients without renal failure.124
Advantages of PD in patients with cardiovascular disease include: better hemodynamic control, less acute hypokalemia (or electrolyte shifts) which could result in arrhythmia, and better control of anemia (important in patients with coronary artery disease). Although a comparison of PD to HD for patients with severe heart failure has not been published, there are several reports of successful PD performance in subjects with severe heart failure.125-130 Tolerance of the procedure (PD), fluid management, prevention of arrhythmias, and patient survival were satisfactory in these reports.
Extensive peripheral or central venous occlusive disease prohibits surgical placement of some types of hemodialysis access. Manifestations of severe ischemia, even gangrene, of the hands follow placement of vascular access in the same wrist or forearm in a few patients with severe peripheral vascular disease, particularly diabetics.131 Marginal vascular beds are at risk for ischemia or reduced perfusion during hypotension, which is frequent in some HD patients. These patients benefit from increased vascular stability, which can be achieved with PD.
Over a period of time, vascular accesses fail and revisions are no longer able to restore adequate blood flow. As a result, the patient receives inadequate hemodialysis and should be evaluated for PD.119,122,132
Home hemodialysis requires an assistant. For patients who prefer dialysis at home, the lack of a hemodialysis assistant may mandate PD. In addition, patients who have transportation problems to a hemodialysis center or live a great distance from a center may prefer home PD.133
The decision to initiate PD rather than HD in children is influenced by a variety of factors. Because of the difficulties in maintaining vascular access in infants and small children, PD is usually the modality of choice when weight is <20 kg. Regular school attendance by children of all ages can best be achieved with a home dialysis procedure. PD is typically preferred over HD. Finally, renal replacement therapy can also best be provided by PD when the child lives a long distance from a pediatric ESRD center.
Absolute Contraindications for PD (Opinion)
Absolute contraindications for PD include:
Documented loss of peritoneal function or extensive abdominal adhesions that limit dialysate flow.
In the absence of a suitable assistant, a patient who is physically or mentally incapable of performing PD.
Uncorrectable mechanical defects that prevent effective PD or increase the risk of infection (eg, surgically irreparable hernia, omphalocele, gastroschisis, diaphragmatic hernia, and bladder extrophy).
Rationale Documented Loss of Peritoneal Function. PD efficiency relies on effective peritoneal blood flow, dialysate flow, sufficient peritoneal surface area, and permeability to allow adequate solute and fluid removal. Any compromise in these functions may result in inadequate peritoneal dialysis and thus the failure of PD.120,134
It should not be assumed that children who have previously undergone extensive abdominal surgery will not achieve successful PD. A trial of PD is warranted in such children and adequate dose delivery must be documented.
Psycho-Neurological Problems. The optimal performance of PD requires certain physical and intellectual capabilities of the patient or caregiver. With major loss of mechanical function or eye-hand coordination, PD becomes difficult to perform. Patients or caregivers are responsible for problem identification and problem solving during PD. If the patient is deemed psychologically incompetent, these tasks and decisions may not be reliably or safely executed.122,133
Abdominal Mechanical Problems. The dialysate in the abdomen must be accessible to the vascular bed of the peritoneal membrane. Any mechanical problem that prevents this (eg, hernia sack, subcutaneous leak) will impair the efficiency of PD. Intra-abdominal pressure increases with dialysate infusion and during the ultrafiltration process, thereby exacerbating any structural defect such as hernia. Some of these abdominal defects are not surgically correctable.122,123
Relative Contraindications for PD (Opinion)
Relative contraindications for PD include:
Fresh intra-abdominal foreign bodies (eg, 4-month wait after abdominal vascular prostheses, recent ventricular-peritoneal shunt).
Body size limitations.
Intolerance to PD volumes necessary to achieve adequate PD dose.
Inflammatory or ischemic bowel disease.
Abdominal wall or skin infection.
Morbid obesity (in short individuals).
Frequent episodes of diverticulitis.
Rationale Fresh Intra-Abdominal Foreign Bodies. Newly implanted abdominal prostheses must be allowed sufficient time for healing to avoid leakage or possible dialysis-related peritonitis with potential spread to the prosthetic device or material. The time required for healing may vary from 6 to 16 weeks.135-137 The bacterial seeding of any vascular prosthesis during hemodialysis is also a risk. The best type of dialysis in this setting is unclear.
Peritoneal Leaks. Peritoneal leakage into subcutaneous tissues, pleural space, or genitalia can be painful and cause local problems. Leaking into the vagina or rectum increases the risk of contamination. Unsatisfactory drainage and clearance, as well as medical complications, such as respiratory compromise in the case of diaphragmatic leak, can occur as a result of such leakage.122,123,133
Body Size Limitations. Body size can be a relative contraindication to PD when the patient is either too small to tolerate the prescribed dialysate volume or too large to achieve adequate dialysis. For patients with little or negligible RRF, there are definite size limitations for adults on CAPD with 4 daily exchanges.138 However, even larger individuals can achieve acceptable clearances if they are treated with a combination of daily CAPD and nocturnal automated PD.139 In large individuals, increase in the exchange volume is more efficient than increase in the number of daily exchanges. However, the patient with the increased exchange volume may experience abdominal pain or discomfort, shortness of breath, or loss of appetite as a result of abdominal pressure.140
Intolerance to PD Volumes Necessary to Achieve Adequate PD Dose. Intolerance to a PD volume is generally not known until it is attempted. Frequent exchanges with small volumes, as observed during automated PD, may not be able to provide an adequate delivered dose of PD. Raising volumes to the limit of tolerance may be problematic in patients with advanced lung disease or patients with recurrent hydrothorax. Infrequently, this may be applicable to some patients with polycystic kidney disease or severe lumbo-sacral disk disease.
Inflammatory or Ischemic Bowel Disease. Inflammatory or ischemic bowel disease or frequent episodes of diverticulitis are relative contraindications to peritoneal dialysis. It is reasonable to assume that there may be increased risk for transmural contamination by enteric organisms in these circumstances.133
Abdominal Wall or Skin Infection. Abdominal wall or skin infection can lead to contamination of the catheter exit site, tunnel, and peritoneal cavity through touch and cross contamination.122 The decision to use PD in patients with a colostomy or ileostomy must be individualized, since successful application of PD has been described in such patients.
Morbid Obesity. Morbid obesity can pose special dilemmas in peritoneal catheter placement, the healing process, and in providing adequate dialysis. The possibility that increased caloric absorption from the dialysate could lead to further weight gain should also be considered.
Severe Malnutrition. Wound healing is compromised in severely malnourished patients. Self-dialysis such as PD may not be suitable for many severely malnourished patients because of inability to comply with the dialysis regime. Furthermore, peritoneal protein losses may not be tolerated.
Frequent Episodes of Diverticulitis. Diverticulitis during peritoneal dialysis often results in peritonitis. Peritoneal dialysis in patients with frequent episodes of diverticulitis places these patients at higher risk for peritonitis.
Indications for Switching from PD to HD (Opinion)
The decision to transfer a PD patient to HD should be based on clinical assessment, the patients ability to reach HD dose target levels, and the patients wishes. In particular, these patients should have vascular access addressed as advised by the NKF-KDOQI Vascular Access Work Group.
Indications for switching from PD to HD include:
Consistent failure to achieve target Kt/Vurea and CCr when there are no medical, technical, or psycho-social contraindications to HD.
Inadequate solute transport or fluid removal. High transporters may have poor ultrafiltration and/or excessive protein losses (relative contraindication, obviously discovered after initiation and the first PET).
Unmanageably severe hypertriglyceridemia.
Unacceptably frequent peritonitis or other PD-related complications.
Development of technical/mechanical problems.
Severe malnutrition resistant to aggressive management (relative).
Patients should be informed of the risks of staying on PD at a level of adequacy below that recommended by their physician.
Rationale The above recommended indications for switching a patient from PD to HD are based on the following considerations:
Consistent Failure to Achieve Target Kt/Vurea and CCr. Consistent failure to achieve the target total solute removal with proper PD prescription management should lead to evaluation of compliance issues and deterrents to appropriate performance of peritoneal dialysis exchanges. After all avenues have been explored, if social or physical issues cannot be overcome, transfer to HD may be necessary as long as the same issues do not deter appropriate therapy (eg, adequate ultrafiltration, single pool delivered Kt/Vurea of 1.2 thrice weekly, etc) on this modality.134,141
Inadequate Solute Transport or Fluid Removal. Peritoneal solute transport determined by PET affects both solute and fluid removal by PD. Obviously, peritoneal transport type is discovered after initiation of PD by the first PET. High transporters may have poor ultrafiltration and/or excessive protein losses (relative contraindication). Excessive protein losses are those that exceed the patients ability to compensate by an increase in dietary protein consumption. However, peritoneal urea and creatinine clearances tend to be adequate in high transporters. Many high transporters with poor ultrafiltration can be effectively dialyzed with short dwell periods and daytime exchanges, but such a regimen may become too burdensome for the patients lifestyle.120,134,141 Low transporters usually have adequate ultrafiltration, but, when they are relatively large, may have inadequate peritoneal clearance of creatinine, but not necessarily a decreased clearance of urea.63
Excessive protein losses can occur if the patients underlying disease includes active nephrosis, if the patient is a high transporter, or if frequent peritonitis occurs. The resulting malnutrition will increase the patients mortality and morbidity. In some children who are actively nephrotic, protein losses may be successfully replaced by supplemental (eg, nasogastric, gastrostomy) tube feedings.
There are medical complications that may develop or have been present prior to initiation of dialysis, but these may become apparent only after peritoneal equilibration testing and adequacy studies.
Inadequate solute transport documented by measures of Kt/Vurea and creatinine clearance must be evaluated. If the maximum PD prescription has been reached (increases in volumes and frequency of exchanges including use of nocturnal cycling) or the procedure is no longer achievable due to lifestyle complications, hemodialysis as an alternative should be explored.120
These guidelines have defined adequate solute transport with regard to urea and creatinine. However, the failure to adequately remove other solutes such as potassium may require switching to another form of renal replacement therapy.
Inadequate ultrafiltration is usually secondary to high transport characteristics or a mechanical defect hampering catheter patency or drainage.142 In rare instances, inadequate ultrafiltration is associated with low peritoneal transport characteristics, probably due to a significant reduction in the area of the peritoneal membrane, or secondary to increased peritoneal lymphatic flow.143
Unacceptably Frequent Peritonitis. The definition of unacceptably frequent peritonitis has to be individually determined for each patient. Such considerations as the availability of hemodialysis facilities will inevitably play a role.
Unmanageably Severe Hypertriglyceridemia. Unmanageably severe hypertriglyceridemia, resulting from, or exacerbated by, the dextrose load intrinsic to the dialysate, may increase the risk for cardiovascular disease.
Development of Technical/Mechanical Problems. Irreparable technical or mechanical defects, such as catheter malposition, resulting in access failure.
Severe Malnutrition Resistant to Aggressive Management (Relative). Due to the continuous protein loss associated with PD, malnourished patients must be aggressively evaluated and treated. If treatment of malnutrition is not successful, transfer to HD is indicated.
RECOMMENDATIONS FOR RESEARCH
The topic of suitability of patients for PD or HD has not been thoroughly investigated. Prospective comparisons of PD and HD for specific ESRD patient categories (eg, those with severe heart failure, those with advanced malnutrition, those with large body size, etc) are needed to define the subsets of ESRD patients which are most suitable or unsuitable for PD.
© 2001 National Kidney Foundation, Inc