[Parathyroidectomy in end-stage renal disease: perioperative management of calcium-phosphorus balance]. / Parathyroïdectomie en insuffisance rénale terminale: prise en charge péri-opératoire de l'équilibre phosphocalcique.

The management of metabolic problems following parathyroidectomy in end stage renal disease remains poorly defined. Hypocalcemia is a common and serious complication in the post-operative period. The objective of the present study was to develop a protocol for the management of patients during the immediate perioperative period based on the best available data from the literature, and to verify its effectiveness and safety in three patients on chronic hemodialysis. A patient management protocol was developed based on data reported in the literature and was subsequently tested on three chronic dialysis patients suffering from tertiary hyperparathyroidism with an indication of parathyroidectomy. According to the literature, the risk of hypocalcemia following parathyroidectomy can be decreased by tight surveillance of calcium levels and preventive administration of calcium and vitamin D analogue to patients at high risk of hypocalcemia. By applying this protocol, profound hypocalcemia was avoided and the immediate post-operative period was uneventful in the three patients under study. In summary, the proposed protocol is safe and effective for the peri-parathyroidectomy management of patients on chronic hemodialysis.

Canadian survey of clinical status at dialysis initiation 1998-1999: a multicenter prospective survey.

AIMS: The current growth in end-stage kidney disease populations has led to increased efforts to understand the impact of status at dialysis initiation on long-term outcomes. Our main objective was to improve the understanding of current Canadian nephrology practice between October 1998 and December 1999. METHODS: Fifteen nephrology centers in 7 provinces participated in a prospective data collection survey. The main outcome of interest was the clinical status at dialysis initiation determined by: residual kidney function, preparedness for chronic dialysis as measured by presence or absence of permanent peritoneal or hemodialysis access, hemoglobin and serum albumin. Uremic symptoms at dialysis initiation were also recorded, however, in some cases these symptom data were obtained retrospectively. RESULTS: Data on 251 patients during 1-month periods were collected. Patients commenced dialysis at mean calculated creatinine clearance levels of approximately 10 ml/min, with an average of 3 symptoms. 35% of patients starting dialysis had been known to nephrologists for less than 3 months. These patients are more likely to commence without permanent access and with lower hemoglobin and albumin levels. Even of those known to nephrologists, only 66% had permanent access in place. CONCLUSIONS: Patients commencing dialysis in Canada appear to be doing so in relative concordance with published guidelines with respect to timing of initiation. Despite an increased awareness of kidney disease, a substantial number of patients continues to commence dialysis without previous care by a nephrologist. Of those who are seen by nephrologists, clinical and laboratory parameters are suboptimal according to current guidelines. This survey serves as an important baseline for future comparisons after the implementation of educational strategies for referring physicians and nephrologists.

Outpatient CAPD catheter salvage for persistent exit-site/tunnel infection.

BACKGROUND: Partial replantation (i.e. replacement of the extraperitoneal portion of the catheter with creation of a new subcutaneous tunnel) has been suggested to avoid catheter removal in patients with persistent exit-site/tunnel infection (ESTI). However, published experience with this technique is limited. METHODS: Partial replantation was performed on an outpatient basis under local anesthesia for seven patients with persistent ESTI of >3 months duration. All patients resumed CAPD immediately following surgery. RESULTS: One patient had dialysate leakage less than 1 week after surgery that required catheter removal. The other patients had no complications and mean catheter survival following surgery was 7. 7 months (range 3.5-13 months). There was no recurrence of ESTI after surgery, although two patients presented with exit-site infection unrelated to the initial episode (i.e. different organism, long latency). Three other patients presented with episodes of peritonitis unrelated to surgery (i.e. delay >1 month) or ESTI (i.e. different organism). CONCLUSIONS: Partial replantation allows significant prolongation of catheter survival without major complications or interruption of CAPD. This novel procedure appears to be an appropriate alternative to catheter removal for the management of persistent ESTI. However, further studies are needed to prospectively compare partial replantation with catheter removal.

Postdialysis urea rebound: determinants and influence on dialysis delivery in chronic hemodialysis patients.

We measured postdialysis urea rebound (PDUR) 30 minutes after dialysis in 92 chronic hemodialysis patients. The impact of PDUR on the estimation of dialysis delivery assessed by urea reduction ratio and Kt/V was evaluated. Total recirculation, access plus cardiopulmonary, was measured at the end of dialysis with the two-needle low blood flow method. The mean age of the 92 patients (49 men and 43 women) was 59.6 +/- 1.4 years. Thirty-eight patients had been receiving erythropoietin therapy for more than 3 months. Fifteen patients had central venovenous access and 77 had peripheral arteriovenous access. Sixty-five patients were dialyzed using hemophan membranes and 27 were dialyzed using polyacrylonitrile membranes. The mean blood flow rate was 240 +/- 28 mL/min and the mean length of the hemodialysis sessions was 3.6 +/- 0.1 hours. Kt/V was calculated with Daugirdas' second-generation formula. The mean PDUR was 16.6% +/- 0.8% (range, 2% to 44%) (n = 92), and significantly decreased the mean urea reduction ratio from 61.7% +/- 0.8% to 55.5% +/- 0.9%, the mean Kt/V from 1.14 +/- 0.03 to 0.97 +/- 0.02, and the mean protein catabolic rate from 1.06 +/- 0.04 to 0.98 +/- 0.02 (P = 0.0001). The effective Kt/V at 30 minutes postdialysis was well predicted by using a recently proposed equation: eKt/V30 = Kt/Vsp - (0.6 x Kt/Vsp/t) + 0.03, with a mean value corresponding also to 0.97 +/- 0.02. However, this estimation was less predictive in patients with very high PDUR. Moreover, PDUR showed only a weak negative correlation with dialysis session length (r = -0.28) and predialysis patient weight (r = -0.29), and showed no correlation with predialysis serum urea level or with blood flow rate. However, dialysis efficiency, as assessed by K/V, presented a correlation of 0.54 with both PDUR and the difference in Kt/V when using urea immediately postdialysis and at 30 minutes. The mean total recirculation was 7.4% +/- 0.6% (n = 86). Postdialysis urea rebound, calculated between 30 or 120 seconds and 30 minutes after dialysis to deduce the influence of recirculations, was reduced but remained important with a mean of 11.8% +/- 0.7%. Thus, total recirculation contributed to nearly 30% of PDUR. The 24 patients with PDUR > or = 20% were compared with the 68 patients with PDUR lower than 20%: women and patients with higher K/V and higher total recirculation presented greater PDUR. Because of relatively few predictive factors for PDUR, its potential considerable impact on dialysis delivery estimation, and the influence of recirculations on the total PDUR amount, total recirculation and PDUR should be determined on an individual basis in chronic hemodialysis patients. The equation proposed to estimate effective Kt/V at 30 minutes is accurate in most patients with PDUR lower than 30% and is a simple alternative.

Differential susceptibility of cardiac cell populations to in vitro immune injury.

In vitro, the culture of enzymatically dissociated fetal heart cells results in the formation of contractile cellular islets surrounded by monolayers of static cells. The islets contract in a spontaneous and synchronous fashion. Using inbred strains of rats sensitized by an allogeneic heart transplant or by three consecutive skin grafts, immune sera were obtained that were assayed at various dilutions against the cell cultures with or without complement. Strain-specific and selective lysis exclusively directed against the static cells was observed. This suggests that noncontractile cells were the specific targets for alloantibody in this fetal heart cell culture system.