Prevalence and epidemiology of hepatitis C infection in patients on peritoneal dialysis in France. French PD centers.

We performed a cross-sectional study to establish the hepatitis C virus (HCV) serologic status for all French patients undergoing peritoneal dialysis (PD) on January 1, 1995. We listed a total of 1508 patients, and the exhaustiveness rate was about of 75% of the whole French PD population treated at this date. Only 47 of the 1508 patients were anti-HCV positive (HCV+): the global HCV prevalence was 3.12%. HCV+ patients were treated by PD for a longer time than HCV-patients (4 +/- 4 vs 2 +/- 2 years; p < 0.001); 89% of the HCV+ patients received blood transfusions; 60% had been previously treated by hemodialysis, and 26% previously received a kidney transplantation. In 49% of the HCV+ patients, HCV antibodies were discovered before the start of the peritoneal dialysis program, and a seroconversion was observed in only 4 (0.27%) of them during the PD treatment. All these patients received blood transfusion. In patients without past history of hemodialysis or transplantation (exclusively treated by PD), HCV prevalence was 1.5%, not far off that of the general population. Peritoneal dialysis seems not to be an additional risk factor for hepatitis C infection in France.

Measurement of hydrostatic intraperitoneal pressure: a necessary routine test in peritoneal dialysis.

This paper summarizes our clinical studies on hydrostatic intraperitoneal pressure (IPP), showing the interest of this measurement in routine clinical practice. IPP can easily be measured routinely be a simple and safe method: the measure of the column of dialysate in the peritoneal dialysis (PD) line before drainage, with point 0 located on the midaxillary line. The normal value is 12 +/- 2 cm of water (cm H2O) with an intraperitoneal volume (IPV) of 2 L, with linear increases of 2.2 cm H2O for each additional liter. IPP must be measured to estimate the tolerance of IPV: the maximal permissible IPV is reached for an IPP of 18 cm H2O, squaring with a decrease of 20% in vital capacity and sometimes arising before clinical symptomatology. However, IPP measured at rest could not predict PD mechanical complications (hernias, dialysis leakages, hemorrhoids, etc.), which are more dependent on parietal previous history or predisposition. IPP is significantly higher during the first three days after peritoneal catheter implantation (17 +/- 3 cm H2O) than during the 12 following days (10 +/- 4 cm H2O). It is recommended to postpone the start of PD until after catheter implantation, and patients should remain supine for the first three days. On the other hand, IPP strongly reduces the overall ultrafiltration (UF) volume: an increase of 1 cm H2O in IPP caused a decrease of 70 mL in global UF after two hours. Therefore, IPP should be measured in diagnosis of losses of UF. However, UF loss during peritonitis is not due to an increase of IPP.

[Connectology for treatment by peritoneal dialysis for chronic renal insufficiency]. / La connectologie pour le traitement par dialyse péritonéale de l'insuffisance rénale chronique.

With the exception of the simple Luer or Spike type systems all of the presently used CAPD devices have a system for intraluminal sterilization and/or an handling assist device. The sterilizing process can be chemical (antiseptics), physical (heat or ultraviolet (UV) light) or mechanical (flush effect). Studies comparing various peritoneal dialysis devices have led to results which diverge greatly, and are not always controlled. Synthesis of these studies shown that disconnect systems (DS) seemed to be not more effective against bacteriological contamination than the last generations of UV non-disconnect (NDS) systems. Efficacy of heat sterilization NDS must be confirmed. The choice of a NDS does not result only from a medical indication.

APD: clinical measurement of the maximal acceptable intraperitoneal volume.

In automated peritoneal dialysis (APD) patients treated with 3-L dwell, intraperitoneal volumes can easily be increased up to 4 or 4.5 L using hypertonic solutions without objective control of their good tolerance. In 20 adult patients treated with continuous ambulatory peritoneal dialysis (CAPD) in good conditions, hydrostatic intraperitoneal pressure (IPP) and pulmonary vital capacity (VC) were measured in strict supine position, after infusing isotonic dialysate in 0.5-L increments from 2 up to 5 L as tolerated, according to intraperitoneal volumes (IPV). None of the patients had cardiac or pulmonary dysfunction. IPP was measured following a routine method previously described. In all cases, experience was stopped when IPP increased over 20 cm H2O and/or VC decreased over 25%. IPV is linearly and positively correlated with IPP (p < 0.0001), and negatively with VC (p = 0.0012), but the reliability of VC is less than that of IPP, particularly in old patients. Clinical symptomatology of bad IPV tolerance never occurred alone and was always associated with an increase in IPP over 20 cmH2O and/or a decrease in VC over 25%. The maximal acceptable IPV is better defined by an IPP less than 18 cmH2O, according with a decrease in VC of less than 20%. Routine measurement of IPP can be used to determine maximal IPV and for optimal PD prescription.

Diagnosis and treatment of chronic lead poisoning in CAPD patients.

In order to screen for abstruse lead poisoning in continuous ambulatory peritoneal dialysis (CAPD) patients, delta-aminolevulinic acid dehydratase (ALAD) levels were measured in 18 CAPD patients, 156 patients treated with hemodialysis (HD), and 420 control patients with normal renal function (NRF). An EDTA (ethylenediamine tetraacetic acid) mobilization test was performed in patients with low levels of ALAD (< 0.40 mumol of porphobilinogen formed per milliliter of red blood cells): 1 g of EDTA was infused IV followed by 20 L of hemofiltrate in HD patients and four bags of dialysate in CAPD patients. Lead was assayed in the ultrafiltrate liquid, the bags of dialysate, and in the 24-hour urine. ALAD levels were significantly lower in CAPD and HD patients than in the NRF subjects. ALAD was significantly correlated with EDTA mobilized lead in both dialysis and NRF patients. Using the usual criteria (EDTA mobilized lead > 800 micrograms/24 hours), the rate of lead poisoning observed was similar in the two groups. These results suggest that ALAD assay followed by the EDTA mobilization test is as effective in CAPD patients as in NRF subjects to diagnose and to treat chronic abstruse lead poisoning.

Evolution of intraperitoneal hydrostatic pressure following peritoneal catheter implantation.

Intraperitoneal hydrostatic pressure (IPP) was measured in 10 patients for 15 days (until day 15) following peritoneal catheter implantation. Tenckhoff catheters were surgically implanted using a transrectal approach. The patients began peritoneal dialysis (PD) immediately, initially with small intraperitoneal fluid volumes (500 mL), gradually increasing to reach 2000 mL by day 7. In one patient PD was delayed until day 7 because of an initial leakage of dialysate. Inspiratory and expiratory IPP were measured daily, with the zero point fixed at the midaxillary line with the patient in the supine position. Despite the small intraperitoneal fluid volumes used initially (500 mL), IPP was much higher in the first 3 days following implantation than in the next 12 days (17 +/- 3 cm of water vs 11 +/- 1 cm of water). IPP remained high until day 3, then gradually decreased in a linear fashion until day 12, despite the increased intraperitoneal volumes used, and then remained constant. In conclusion, IPP was found to be significantly higher for 3 days following intraperitoneal catheter implantation, whichever intraperitoneal volume was used. This may be due to tense abdominal muscles from pain caused by the surgery or because of reduced intraperitoneal compliance at the beginning of PD.

Intraperitoneal hydrostatic pressure and ultrafiltration volume in CAPD.

The intraperitoneal hydrostatic pressure (IPP) and overall ultrafiltration (UF) volume were measured in 34 patients after a 2-hour exchange with 2 L of dialysate containing 3.86% glucose. These patients had been treated with continuous ambulatory peritoneal dialysis (CAPD) on average for 26 +/- 20 months under stable conditions. The patients were at rest during the 2-hour exchange. The normal IPP measured with the patient lying completely flat was on inspiration (IPPinsp) 14 +/- 4 cm of water (cmH2O) and on expiration (IPPexp) 12 +/- 3 cm H2O, for an intraperitoneal volume of 2820 +/- 319 mL. The mean UF was 744 +/- 323 mL. The mean IPP (IPPmean), defined by (IPPinsp+IPPexp)/2, had a negative linear correlation to the UF volume (r = 0.66; p = 0.0001). The linear regression test showed that an increase of 1 cm H2O in the IPPmean reduced the overall UF volume by 70 mL in 2 hours. In conclusion, even though the UF is produced by the osmotic pressure of the dialysate, it is also influenced to a great extent by the intraperitoneal hydrostatic pressure, which should not be ignored.

Routine measurement of hydrostatic intraperitoneal pressure.

A simple, non-invasive and well-tolerated technique for routine measurement of intraperitoneal hydrostatic pressure (IPP) in patients treated with peritoneal dialysis (PD) is presented. The height of the dialysis fluid in the PD line was measured, under atmospheric pressure, before drainage and during inspiration (IPPinsp) and expiration (IPPexp), taking the axillary line as the reference point of the resting subject in strict supine position. Normal values were established for a population of 18 patients treated with PD for 19.8 +/- 20.9 months under clinical and biological stable conditions. For an intraperitoneal volume of 2,820 +/- 419 ml, IPPinsp = 14 +/- 2 cmH2O; IPPexp = 12 +/- 2 cmH2O; IPP mean (defined as (IPPinsp+IPPexp)/2) = 13 +/- 2 cmH2O; IPP (defined as IPPinsp - IPPexp) = 2 +/- 2 cmH2O. IPP could not predict mechanical complications (hernia, hemorrhoids, dialysis fluid leakage) but the maximal IPPexp clinically tolerated was 20 cmH2O.

Intraperitoneal pressure, peritoneal permeability and volume of ultrafiltration in CAPD.

Peritoneal permeability (PP), hydrostatic intraperitoneal pressure (IPP) and the overall volume of ultrafiltration (UF) were measured in 23 patients treated by CAPD under stable conditions. PP, IPP and UF were measured during the same exchange with a 2-liter bag with 3.86% glucose, dwell time of 2 hours. PP was evaluated with 3 indices: glucose peritoneal desaturation at 2 hours, urea peritoneal saturation at 2 hours, and crossing time of glucose and urea peritoneal equilibration curves. IPP was evaluated at inspiration (IPPinsp) and at expiration (IPPexp)-giving IPPmean-by measuring the height of the dialysis fluid in the PD line under atmospheric pressure, with point zero located on the axillary line of the subject in strict supine position. Net UF volume was inversely correlated with IPPmean. The net UF volume was strongly affected by IPP since a 1 cmH2O increase in IPPmean caused a decrease of 74 ml in global UF in 2 hours, probably by modification of the lymphatic reabsorption and perhaps of the transcapillary UF.