Use of peritoneal dialysis for Use of peritoneal dialysis for the treatment of acute renal the treatment of acute renal

failurefailure

Ri 李念偉 May 1, 2006

Commonly Used Definitions of ARF

An increase in serum creatinine of >0.5 mg/dL over the base-line value in <2 wks

An increase in serum creatinine >20% if baseline serum creatinine >2.5 mg/dL

A reduction in the calculated creatinine clearance of 50 percent

Introduction

The management of the patient with ARF requires meticulous attention to fluid, acid-base, and electrolyte balance as well as the removal of uremic toxins. PD is an overlooked procedure for dialytic support in acute renal failure, being primarily used for the treatment of patients with ESRD. Acute PD remains a viable option for the treatment of selected patients with ARF, particularly those who are hemodynamically compromised or have severe coagulation abnormalities

Advantages of PD (I)

It is widely available and technically easy to perform.

Large amounts of fluid can be removed in hemodynamically unstable patients; this fluid removal may also permit the administration of parenteral nutrition.

Disequilibrium syndrome is not precipitated because of slow solute removal.

Advantages of PD (II)

Gradual correction of acid-base and electrolyte imbalance may be performed.

PD access placement is relatively easy, particularly in children.

Arterial or venous puncture and anticoagulation are not required.

Dosing is easy, particularly in children.

Practicality of PD

Acute PD is widely available and can be provided without significant inconvenience in any hospital.The procedure is relatively simple, can be performed by trained intensive care unit (ICU) nursing staff.

Hemodynamic Stability The continuous nature of acute PD involves the slow removal of solutes (eg, urea) and fluid. It is therefore desirable in hemodynamically unstable patients because large amounts of fluid can be removed over a prolonged period of time.

Slow Correction of Metabolic

Imbalances

Acute PD enables continuous correction of acid-base status and electrolyte imbalance and the gradual removal of nitrogenous waste products.

The slow removal of uremic toxins with acute PD is not associated with the development of the disequilibrium syndrome.

Easy Access Placement (I)Acute PD access can be achieved without serious difficulty by inserting a semirigid catheter or by placing a Tenckhoff catheter.

The semirigid catheter insertion can be performed at the bedside by a nephrologist or surgeon.

Easy Access Placement (II)

The Tenckhoff catheter is usually placed in the operating room by a surgeon; this flexible catheter is more comfortable for the patient who is moving around in bed and operative insertion avoids the occasional development of intestinal perforation with percutaneous insertion.

Systemic Anticoagulation Not Required (Excellent Candidates for Acute PD)

Those with a bleeding diathesis

Patients in the immediate postoperative period

Trauma patients

Patients with intracerebral hemorrhage

Hyperalimentation

The use of hypertonic glucose PD solutions provides additional calories which is a benefit in malnourished patients.

Tolerated in Children Acute PD has been frequently utilized and is the preferred form of therapy for dialysis children with ARF. The technique is convenient, relatively simple, and safe to perform in children, particularly since peritoneal access is easily obtained. Acute PD circumvents the need for arterial or venous puncture, both of which are difficult in children.

Absolute Indication for Acute PD

The need for dialysis and the inability to perform any other renal replacement technique

Relative Indications for Acute PD

Hemodynamically unstable patients

The presence of a bleeding diathesis or hemorrhagic conditions

Difficulty in obtaining blood access

Removal of high molecular weight toxins (>10 kD)

Heart failure refractory to medical management

Contraindications for Acute PD (I)

Recent abdominal and/or cardiothoracic surgery

Diaphragmatic peritoneal-pleural connections

Severe respiratory failure

Life-threatening hyperkalemia

Severe volume overload in a patient not on a ventilator

Contraindications for Acute PD (II)

Severe gastroesophageal reflux disease

Ongoing peritonitis

Abdominal wall cellulitis

Acute renal failure in pregnancy

Mechanical Complications of Acute PD

Abdominal pain or discomfort

Intraabdominal hemorrhage

Leakage

Bowel perforation

Infectious Complications of Acute PD

Infectious complications are common, particularly peritonitis. The incidence of peritonitis can be significantly decreased by maintaining sterile precautions during the placement of acute PD catheters and by preventing contamination during exchanges.

Pulmonary Complications of Acute PD

Basal atelectasis and pneumonia

Pleural effusion

Aspiration

Cardiovascular Complications of Acute

PD

Reduced cardiac outputCardiac arrhythmias

Metabolic complications of Acute PD

Hyperglycemia

Hypernatremia

Hypokalemia

Protein losses

Effect on Mortality

A paucity of data exists concerning the effect on mortality of PD versus intermittent hemodialysis or continuous renal replacement therapies other than PD in patients with acute renal failure.

Most studies have shown that the mortality and incidence of renal recovery with acute PD was at least comparable to hemodialysis.

An Original Article from NEJM (I)

Hemofiltration and Peritoneal Dialysis in Infection-Associated Acute Renal Failure in Vietnam Volume 347:895-902 Sep 19, 2002

The primary objective of the study was to assess the efficacy, safety, practicality, and cost of short-term peritoneal dialysis as compared with pumped venovenous hemofiltration in a well-equipped hospital in a developing country.

An Original Article from NEJM (II)

The primary end point was the rapidity of resolution of metabolic abnormalities, indicated by the rates of change in and normalization of the venous plasma creatinine concentration and arterial plasma pH.

Mortality and the cost of treatment were secondary end points.

Patients had either severe falciparum malaria or sepsis-related acute renal failure.

Results

Between 1993 and 1998, 70 patients entered the study.

There was no significant difference in any of the base-line variables between the groups (36 patients assigned to peritoneal dialysis and 34 to hemofiltration).

Falciparum malaria was the underlying cause of acute renal failure in 48 patients (69 percent). The other 22 patients all had presumed bacterial sepsis.

Correction of Metabolic Abnormalities

Plasma [Cre] declined more than twice as rapidly in the group assigned to hemofiltration.

The rate of resolution of acidosis was considerably faster and normalization more complete in the group assigned to hemofiltration.

A significantly higher proportion of patients assigned to hemofiltration had a normal pH and base deficit at the end of the session of renal-replacement therapy.

Mortality

There were 17 deaths (47 percent) in the group assigned to peritoneal dialysis as compared with 5 (15 percent) in the group assigned to hemofiltration (relative risk, 3.2; 95 percent confidence interval, 1.3 to 7.7; P=0.005). In a logistic-regression model including underlying disease (malaria or bacterial sepsis) and the presence or absence of jaundice as explanatory variables, peritoneal dialysis was significantly associated with death (odds ratio, 5.1; 95 percent confidence interval, 1.6 to 16).

Economic Implications

PD: the mean costs per survivor were $3,000 (95 percent confidence interval, $2,210 to $3,790)

Hemofiltration: $1,340 (95 percent confidence interval, $1,130 to $1,560)

Peritoneal Dialysis in Acute Renal Failure — Why the Bad Outcome? (I)

An editorial in the same issue of NEJM

Given that increased adequacy of solute removal has been linked to better outcomes in patients with acute renal failure who are receiving either hemodialysis or venovenous hemofiltration, part of the survival benefit of hemofiltration in this study was probably due to better toxin removal.

Peritoneal Dialysis in Acute Renal Failure — Why the Bad Outcome? (II)

Whereas venovenous hemofiltration was conducted with more or less state-of-the-art methods, the peritoneal-dialysis techniques employed were not optimal: rigid, rather than flexible, catheters were used, and dialysate bags were hung and changed manually, rather than with the use of a cycler.The peritoneal dialysate was made in the hospital pharmacy (not commercial).

Peritoneal Dialysis in Acute Renal Failure — Why the Bad Outcome? (III)

High osmolality of peritoneal-dialysis fluid and high glucose levels have been linked to stunning and dysfunction of leukocytes.

High splanchnic-blood glucose levels may stimulate the growth of the erythrocytic stage of malaria organisms in the liver.

Peritoneal Dialysis in Acute Renal Failure — Why the Bad Outcome? (IV)

Whatever the explanation for the findings, the results are of great practical importance to nephrologists treating patients who have acute renal failure associated with malaria or sepsis, since the authors suggest that peritoneal dialysis should not be used. Another lesson to be learned is that we must also determine whether there are technique-specific factors that affect outcome.

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