1. F.SAMADIAN NEPHROLOGIST
IN THE NAME OF GOD
F.SAMADIAN NEPHROLOGIST

2. Peritonitis and Exit Site Infection

4. the introduction of Y-set and double-bag disconnect systems has reduced this to approximately one episode per patient every 24 months

6. Potential routes of infection:
Intraluminal
Periluminal
Transmural
Hematogenous
Transvaginal

7. Intraluminal:
This allows bacteria to gain access to the peritoneal cavity via the catheter lumen

8. Periluminal:
Bacteria present on the skin surface can enter the peritoneal cavity via the peritoneal catheter tract

9. Transmural:
Bacteria of intestinal origin can enter the peritoneal cavity by migrating through the bowel wall
This is the usual mechanism of peritonitis associated with diarrheal states and/or instrumentation of the colon and may be seen also with strangulated hernia

10. Hematogenous:
Less commonly, peritonitis is due to bacteria that have seeded the peritoneum from a distant site by way of the bloodstream

11. Transvaginal:
it may explain some instances of Candida peritonitis

13. The responsible pathogen is almost always a bacterium, usually of the Gram-positive variety

14. The occurrence of fungal peritonitis (e.g., Candida) is uncommon

15. Infections with Mycobacterium tuberculosis or other type of mycobacteria have been reported but are unusual

16. Diagnostic criteria for peritonitis:
At least two of the following three conditions should be present:
symptoms and signs of peritoneal inflammation
cloudy peritoneal fluid with an elevated peritoneal fluid cell count (more than 100/mcL) due predominantly (more than 50%) to neutrophils
demonstration of bacteria in the peritoneal effluent by Gram stain or culture

17. Symptoms and signs:
The most common symptom of peritonitis is abdominal pain
However, peritonitis should be suspected whenever a patient suffers from generalized malaise, particularly if nausea, vomiting, or diarrhea is also present

18. Not all abdominal pain in a patient receiving PD is peritonitis

19. Strangulated hernia is a common mimic for peritonitis

20. Cloudiness of the fluid:
The peritoneal fluid generally becomes cloudy when the cell count exceeds /mcL

21. In most patients, sudden onset of cloudy fluid with appropriate abdominal symptoms is sufficient evidence of peritonitis to warrant initiation of antimicrobial therapy

22. However, peritoneal fluid cloudiness may be due to other factors (e. g
However, peritoneal fluid cloudiness may be due to other factors (e.g., fibrin, blood, or, rarely, malignancy or chyle)

23. On the other hand, a relatively translucent peritoneal fluid does not completely exclude the possibility that peritonitis is present (early in the course of peritonitis)

24. The absolute peritoneal fluid cell count in CAPD patients is usually <50 cells/mcL and is often <10 cells/mcL

25. Normally, the peritoneal fluid contains predominantly mononuclear cells (macrophages, monocytes, and, to a lesser extent, lymphocytes)

26. The percentage of neutrophils does not normally exceed 15% of the total nonerythrocyte cell count and a value >50% strongly suggests peritonitis, whereas one >35% should raise suspicion

27. Vancomycin or a first-generation cephalosporin such as cefazolin or cephalothin is used in combination with an antibiotic to cover Gram-negative organisms such as ceftazidime

28. It is now recommended that aminoglycosides be avoided if possible in patients with residual renal function because of their nephrotoxicity

29. CAPD
Loading dose: Infuse 2 L of 1.5% dextrose dialysis solution containing: 1 g ceftazidime 1 g cefazolin 1,000 units/L heparin   Allow to dwell for 3-4 hours.
Continue regular CAPD schedule. Add 125 mg per L ceftazidime, 125 mg/L cefazolin, and 1,000 units/L heparin to each dialysis solution bag

30. If a patient appears toxic recommend a single loading dose IV

31. Duration of therapy:
If patient improvement is prompt, antimicrobial therapy should be continued for a total of 14 days
If a cephalosporin is being used, then some physicians will switch to PO therapy after the first 5 days

32. Severe S. aureus infections require antimicrobials for 3 weeks, and treatment with one IP antistaphylococcal drug plus PO rifampin is recommended

33. Patients in whom S. aureus peritonitis develops not uncommonly are found to carry this organism in the nose

34. This can be accomplished with intranasal mupirocin (b. i. d
This can be accomplished with intranasal mupirocin (b.i.d. for 5 days every 4 weeks) or oral rifampin (300 mg b.i.d. for 5 days every 3 months

35. Exit site infection
Approximately one fifth of peritonitis episodes are temporally associated with exit site and tunnel infections

36. Etiology and pathogenesis:
Exit site infections are predominantly due to S. aureus or Gram-negative organisms, particularly Pseudomona
In contrast to peritonitis, S. epidermidis is the causative organism in <20% of patients
eradication of the carrier state is very helpful to effective management

37. Treatment is dependent on whether there is erythema alone or erythema in conjunction with purulent drainage
In the former case, topical treatment with hypertonic saline compresses, hydrogen peroxide, or mupirocin 2% ointment is usually sufficient

38. Treatment is more problematic and more prone to failure when there is purulent drainage
some exit site infections extend into the subcutaneous tunnel

39. The major risk factor for exit site infection is staphylococcal nasal carriage

40. Persistently positive nasal cultures are associated with a 3-4 fold increase in risk of staphylococcal exit site infection

41. Protocols used include
-rifampin (600 mg PO for 5 days),
-mupirocin (2% ointment twice daily for 5 days every 4 weeks)
-trimethoprim-sulfamethoxazole (single-strength tablet three times weekly)

42. Mechanical Complications of Peritoneal Dialysis

43. The instillation of dialysis fluid into the peritoneal cavity is accompanied by an increase in intra-abdominal pressure (IAP)

44. The two principal determinants of the magnitude of the increased IAP are dialysate volume and the position of the patient during the dwell

45. The supine position is associated with the lowest IAP for a given dialysate volume; sitting entails the highest

46. Hernia formation
as many as 10%-20% of patients may develop a hernia at some time on peritoneal dialysis

47. Potential risk factors for hernia formation
-Large dialysis solution volume
-Sitting position
-Isometric exercise
-Valsalva maneuver (e.g., coughing)
-Recent abdominal surgery
-Pericatheter leak or hematoma
-Obesity
-Multiparity
-Congenital anatomical defects

48. Many different types of hernias have been described in the peritoneal dialysis patient

49. Types of hernias reported in peritoneal dialysis patientsVentral Epigastric Pericatheter Umbilical Inguinal (direct and indirect) Femoral Spigelian Richter Foramen of Morgagni Cystocele Enterocele

50. Pericatheter hernias need to be differentiated from masses caused by a hematoma, seroma, or abscess

51. Ultrasonography
CTscan
MRI

52. Small hernias pose the greatest risk of incarceration or strangulation of bowel

53. Abdominal wall and pericatheter leak

54. Abdominal wall leak may be difficult to diagnose clinically

55. It may be mistaken for ultrafiltration failure when dialysate returns are less than the instilled volume

56. The diagnosis should be considered with:
-decreased effluent volumes
-weight gain
-protuberant abdomen
-absence of generalized edema

57. The patient should stand during the examination as this may reveal asymmetry of the abdomen

58. Diagnosis can be proven using contrast CT scanning

59. Pericatheter leak usually occurs as a postoperative complication of catheter implantation

60. In most cases, the leak seals spontaneously
If it persists, the catheter should be removed and reinserted at another site

61. In contrast to pericatheter leaks, abdominal wall leaks can occur early or late

62. Sometimes surgical repair is feasible

63. Vaginal leaks can also occur
Some may result from tracking of dialysate through the fallopian tubes and may resolve with tubal ligation

64. Genital edema:
Dialysate can reach the genitalia by two routes

65. One is by traveling through a patent processus vaginalis to the tunica vaginalis, resulting in hydrocele

66. The second route is through a defect in the abdominal wall, often associated with the catheter

67. This complication is often painful and distressing to the patient who is quick to bring it to medical attention

68. CT peritoneography should be performed to distinguish which route has led to the genital swelling (i.e., anterior abdominal wall or processus vaginalis)

69. Peritoneal dialysis should be temporarily stopped
Bed rest and scrotal elevation are helpful

70. A leak via a patent processus vaginalis can be repaired surgically

71. If the leak is through the anterior abdominal wall, replacement of the catheter can be helpful

72. Respiratory complications:
Hydrothorax
Under the influence of raised IAP, dialysate can travel from the peritoneal to the pleural cavity, leading to a pleural effusion composed of dialysis effluent

73. These defects may be congenital, in which case hydrothorax can occur with the first dialysis exchange, or acquired, whereby hydrothorax can be a late complication

74. They occur almost exclusively on the right side, probably because the left hemidiaphragm is mostly covered by heart and pericardium

75. Symptoms of hydrothorax range from asymptomatic pleural effusion to severe shortness of breath

76. Such symptoms may worsen with administration of hypertonic dialysate, which raises IAP

77. Thoracentesis can be done for diagnosis or to relieve symptoms

78. The most diagnostic feature of the pleural fluid is the very high glucose level, although this is not always a consistent finding

79. It is typically transudate, with variable numbers of leukocytes
transudative
It is typically transudate, with variable numbers of leukocytes

80. Radionuclide scanning with technetium is also helpful

81. Back pain:
The presence of dialysate in the peritoneal cavity both raises IAP and swings the center of gravity forward, producing lordotic stress on the lumbar vertebrae and paraspinal muscles

82. Some patients benefit from the performance of more frequent exchanges with smaller dialysate volumes

83. Metabolic Complications of Peritoneal Dialysis

84. Glucose absorption
Glucose has the advantage of being cheap, stable, and relatively nontoxic to the peritoneum

85. up to 100g per day of glucose may be absorbed, which represents 500-800 kcal per day

86. This constitutes a significant portion of the recommended total energy intake of about 2,500 kcal per day (35 kcal/kg per day) in a 70-kg patient

87. In some patients, this provides a welcome source of calories since achieving the nutritional recommendation for PD is often difficult

88. In patients who start PD obese, the glucose loading from PD may contribute to further weight gain

89. glucose absorption results in increased insulin secretion, which together with insulin resistance (a common feature of chronic renal failure) results in plasma insulin levels that are persistently high

90. Hyperinsulinemia may be an independent risk factor for the development of atherosclerosis

91. Patients who were previously well controlled on oral hypoglycemics often require increased doses of these medications, and they may even require a change to insulin therapy after the initiation of PD

92. To minimize glucose absorption, patients should be advised on appropriate salt and water management, which will diminish the need for hypertonic solutions to maintain fluid balance

93. Lipid abnormalities
patients on PD have a variety of lipid abnormalities

94. Typically, they have high total and LDL cholesterol, high triglycerides, low HDL cholesterol, high apoB, low apoA-I, and high lipoprotein(a) levels

95. Compared with hemodialysis patients, the most striking differences are the high apoB protein and LDL cholesterol levels, which are usually normal in hemodialysis patients

96. Protein loss:
PD is associated with significant loss of protein across the peritoneum

97. This loss is about 0.5 g/L of dialysate drainage, but may be higher and account for as much as g per day

98. The major component of the protein losses is albumin

99. Acute peritoneal inflammation is associated with substantially greater protein losses, and a rapid reduction in serum albumin is common during episodes of peritonitis

100. The protein loss itself may become an indication to terminate peritoneal dialysis temporarily or, on occasion, permanently

101. Hypokalemia/hyperkalemiakm:
PD solution contains no potassium
Usually only patients who are noncompliant in performing their dialysis exchanges or who have excessive potassium intake have ongoing problems with hyperkalemia

102. However, hypokalemia has been reported in 10%-30% of CAPD patients

103. These cases are usually associated with poor nutritional intake, and most can be managed by liberalizing the diet

104. Dialysis solution calcium level
PD solutions are available with 2.5 mEq/L or 3.5 mEq/L calcium concentrations

105. The 3.5 mEq/L dialysis solution keeps the patient in positive calcium balance

106. The standard solution is now considered to be the 1. 25 mM (2
The standard solution is now considered to be the 1.25 mM (2.5 mEq/L) calcium solution

107. Hypocalcemia is not common in patients on PD because of the widespread use of calcium-based phosphate binders and vitamin D