[CPFA (coupled plasma filtration absorption) treatment of septic shock. A retrospective study of nine patients]. / Trattamento con CPFA (coupled plasma filtration absorption) dello shock settico. Uno studio retrospettivo di 9 casi.

Coupled plasma filtration absorption (CPFA) can increase blood pressure in septic shock and reduce fever during and after treatment. It is not able to stop the activation of intravascular coagulation and does not reduce the need for dialysis or the overall mortality.

The natural history of autogenous radio-cephalic wrist arteriovenous fistulas of haemodialysis patients: a prospective observational study.

BACKGROUND: Clinical practice guidelines have supported vascular access surveillance programmes on the premise that the natural history of the vascular access will be altered by radiological or surgical interventions after vascular access dysfunction is detected. The primary objective of this study was to assess the actual risk of thrombosis of autogenous radio-cephalic (RC) wrist arteriovenous fistulas (AVFs) without any pre-emptive interventions. METHODS: We enrolled 52 randomly selected adult Caucasian prevalent haemodialysis (HD) patients, all with autogenous RC wrist AVFs, into this prospective, observational study aimed to follow the natural history of their AVFs for 4 years. The protocol prescribed avoiding any surgical or interventional radiological procedures until access failure (AVF thrombosis or a vascular access not assuring a single-pool Kt/V > or =1.2). The subjects underwent yearly assessments of vascular access blood flow rate by means of a saline ultrasound dilution method. RESULTS: All failures of vascular access were due to AVF thrombosis; none were attributed to an inadequacy of the dialysis dose. AVF thrombosis occurred in nine cases; a rate of 0.043 AVF thrombosis per patient-year at risk. A receiver operating characteristic curve, evaluating the diagnostic accuracy of baseline vascular access blood flow rate values in predicting AVF failure, showed an under-the-curve area of 0.82+/-0.05 SD (P = 0.01). The value of vascular access blood flow rate, identified as a predictor of AVF failure, was <700 ml/min with an 88.9% sensitivity and 68.6% specificity. When subdividing the population of AVFs into two groups according to the baseline vascular access blood flow rates, two out of the nine thromboses occurred among the AVFs that had baseline blood flow rates >700 ml/min (n = 31), whereas seven occurred among the AVFs that had baseline blood flow rates <700 ml/min (n = 21). The 4 year cumulative actuarial survival was 74.36 and 20.80%, respectively (log-rank test, P = 0.04). The 24 AVFs that remained patent at the end of the 4 years maintained a median blood flow rate > or =900 ml/min at all time points studied. Worth noting is that, five of them (20.8%) remained patent throughout the study with a blood flow rate consistently < or =500 ml/min. CONCLUSIONS: This study shows a very low rate of AVF thrombosis per patient-year at risk and a high actuarial survival of autogenous RC wrist AVFs, particularly of those having a blood flow rate >700 ml/min. Thus, a vascular access blood flow rate <700 ml/min appears to be a reliable cut-off point at which to start a closer monitoring of this parameter-which may lead to further investigations and possibly interventions relevant to the function of the AVFs.

The impact of relapsing sterile icodextrin-associated peritonitis on peritoneal dialysis outcome.

BACKGROUND: The emphasis in peritoneal dialysis (PD) has shifted from a therapy with short-term goals to one of prolonging the life of the peritoneal membrane. Icodextrin (ICO), a starch-derived glucose polymer that is metabolized to maltose, is a valuable osmotic agent in the treatment of PD patients with defective ultrafiltration. However, ICO can cause sterile peritonitis. The manufacturer has recently withdrawn a series of batches of ICO solutions due to evidence of bacterial contamination (a bacterial cell wall breakdown, peptidoglycan). Some cases have been reported of culture-negative ICO-associated peritonitis which relapse on re-challenge. METHODS: We started to use ICO in chronic uremic PD patients in 1997. Ten patients out of 82 treated in our PD unit were exposed to ICO from 1997-2002. We registered 50 peritonitis episodes in this period: 34 were bacterial and 16 culture-negative. Among the 16 episodes of sterile peritonitis, 6 occurred in patients treated with ICO. Four of the 6 ICO treated patients experienced relapsing culture-negative episodes of peritonitis. We reviewed the records of the four patients. RESULTS: The first episodes of sterile ICO-associated peritonitis occurred between February-May 2002. These were clinically very mild and the only sign was abdominal discomfort and a cloudy dialysate containing a number of WBC/mm(3) ranging from 500-800. Cultures were negative. All the ICO solutions were from the batches withdrawn by the manufacturer. ICO (with new batches of solution) was re-introduced in all patients some weeks later to improve ultrafiltration. A new episode of sterile peritonitis occurred with the same characteristics as described above. Three of the four patients were re-challenged with new batches of ICO solution and again sterile peritonitis occurred. One patient was switched directly to hemodialysis (HD); the others were transferred to a program of automated PD including hypertonic glucose solutions. In 8 months all patients were switched to HD because of the failure of ultra-filtration. It is possible that the first episode of sterile peritonitis, associated with the use of an ICO batch suspected of having high peptidoglycan levels could have induced sensitization to ICO, which in turn could have been the cause of the relapse on re-challenge. CONCLUSIONS: The disappointing result of the relapsing culture-negative ICO-associated peritonitis in our patients was the unavoidable switch to HD, due to the inability of the hypertonic glucose solutions to ensure an adequate ultrafiltration. The moral of the story is that the pharmaceutical industry should market products that are more biocompatible and safer for chronic treatments such as PD.

A comparison of methods for the measurement of hemodialysis access recirculation.

BACKGROUND: NKF K-DOQI clinical practice guidelines recommend a regular monitoring of vascular access (VA) through several methods, such as VA recirculation (AR). Assessment of AR is crucial to avoid inefficiency of hemodialysis (HD). A non-urea based method has been developed (ultrasound dilution Transonics Hemodialysis Monitor--USM) which is considered the gold standard together with the two needle revised slow-stop-flow BUN recirculation method (S/SF). Furthermore, some other indicator dilution techniques, utilizing the dilution of serum potassium (K), glucose, hematocrit (Hct) and hemoglobin (Hb) have been recently described. METHODS: Aim of the study was to compare some of these tests with the gold standards (the USM and the revised S/SF methods). One hundred-five adult HD patients were selected to participate; all had autogenous radiocephalic wrist arteriovenous fistulas (AVF). Studies included the assessment of AR by means of: A. non-urea based methods: 1. at the start of HD a blood sample was obtained from the arterial needle at the time of needle insertion for the measurement of serum K, Hb and Hct (respectively K1, Hb1 and Hct1). The blood circuit was connected and the pumping of blood was started at 200 mL/min. After 18 seconds, blood samples were drawn from the arterial line sampling port (K2, Hb2, Hct2). At this time, if AR is present, part of the saline entering the blood stream will dilute K2, Hb2, Hct2.AR (%) is =100 x (1 - Hb2/Hb1) in the case of Hb; 2. during the first 30 min USM was performed in triplicate (the blood pump rate was set to 300 mL/min); B. a urea based method: the revised S/SF method was performed at 30 min. RESULTS: AR was absent when measured by means of the USM; it was absent even when cannulating the patients with the two needles placed as close as possible. AR measured by means of the USM was significantly different from AR measured by means of the other methods (means +/- SD, one-way analysis of variance, p < 0.0001). CONCLUSIONS: AR in autogenous radiocephalic wrist AVFs was zero when measured by means of the USM; the revised S/SF method and the tests employing the dilution of Hb, Hct and serum K can be considered a valuable alternative to the USM.

Hyperbaric oxygen therapy for calcific uremic arteriolopathy: a case series.

Calcific uremic arteriolopathy (CUA), also referred to as calciphylaxis, is a syndrome of small vessel calcification of unknown etiology causing painful violaceous skin lesions that progress to non-healing ulcers and gangrene. It is observed mainly in patients with end-stage renal disease, is associated with high morbidity and mortality and has no standard treatment at the present time. Although parathyroidectomy (PTX) has been advocated in some cases, other studies have not found this effective. Hyperbaric oxygen therapy (HOT) consists of breathing 100% O2 at higher than ambient pressure, with the patient inside a sealed chamber. HOT has been used with some success in the treatment of selected problem wounds (those that fail to respond to established medical and surgical management). They are often severely hypoxic; restoration of tissue PO2 to normal or above-normal enhances fibroblast proliferation and collagen production as well as angiogenesis. The present is the largest retrospective case series of CUA treated by means of HOT reported so far and comprises 11 chronic uremic patients on dialysis (9 hemo- and 2 peritoneal dialysis, 6 females and 5 males, mean age 56 +/- 7 SD years, time on dialysis 163 +/- 84 SD months). Four patients had biopsy-proven CUA; 3 had diabetic nephropathy as a cause of uremia; 2 were obese and 3 had a consistent increase of serum calcium x phosphorus product; 3 patients had severe secondary hyperparathyroidism (II(nd) HPTH) and two had been submitted to subtotal PTX some years before CUA; two others had already had the limb amputated. Lesions were in the legs, except for one in a hand, and were prevalently ulcers and necrosis. The number of sessions in each HOT cycle ranged from a minimum of 20 to a maximum of 108 (mean 40.6 +/- 29.0). The results of two therapies cannot be evaluated (one was interrupted by the patient after 10 sessions, and one ended with the death of the patient due to ventricular arrhythmia after eight sessions). Eight of the nine remaining had excellent results with healing of the skin ulcers, but the ninth got worse, making it advisable to amputate the foot. In conclusion, CUA appears to result from a multitude of predisposing and/or sensitizing events that are commonly present in the uremic milieu. The specific factors that induce this disorder in an individual patient are not known. The present retrospective study supports a role of HOT in many cases of CUA, especially considering that, in the absence of severe II(nd) HPTH, there are very few therapeutic options.