PD in ARF

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PD in ARF

• Brad Weaver, MD
• 2/19/08

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PD vs. HD

• PD often overlooked as treatment option in ARF
• Most useful compared to HD in patients who are
• Hemodynamically unstable - alternative to CVVH
• Coagulopathic avoids venous puncture and
  systemic anticoagulation

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Other advantages of PD

• Avoids disequilibrium syndrome because of slow
  solute removal
• Widely available
• Hyperalimentation via diffusion of glucose (in
  malnourished patients)
• Can be used to treat concomitant hypothermia or
  hyperthermia

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Contraindications to PD in acute setting

• Severe hyperkalemia
• Abdominal and thoracic surgery hydrothorax may
  develop after thoracic surgery
• Respiratory problems increases intraabdominal
  pressure
• GERD
• Pregnancy

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Access

• Semirigid (Cook) catheter
• Can be done at bedside without surgeon
• Must be removed within 72 hours because of risk
  of bowel perforation and infection
• Cuffed permanent catheter
• More comfortable
• Avoids repeated punctures

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Cuffed permanent catheters
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Acute PD Rx

• Short dwell times
• Can be done manually or by automated cycling
  device
• Warm PD fluid to body temperature
• Often dialysate volume 2-3L and dialysate flow
  rate 2-6L/hr
• Important to ensure complete outflow at finish

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Popovich, Ann Intern Med 1978 88449
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Standard PD solution
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Additives

• Heparin 200 to 500u per liter, not absorbed
  systemically
• Potassium
• Insulin
• 4-5u/L for 1.5 dextrose
• 5-7u/L for 2.5 dextrose
• 7-10u/L for 4.5 dextrose

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Hypernatremia

• A possible complication of acute PD
• Aquaporin 1 channels on peritoneal membrane are
  activated by hypertonic dialysate
• Free water moves into peritoneal space
• Sodium then diffuses down its concentration
  gradient but may be limited by short exchange
  time
• Treat by increasing exchange time or by
  decreasing dialysate tonicity

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Phu, N Engl J Med 2002

• 70 patients in Vietnam with ARF from malaria or
  sepsis
• Randomized to acute PD or CVVH
• Increased mortality in PD group vs. CVVH (47
  versus 15 percent, odds ratio 5.1, 95 percent CI
  1.6 to 16).