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L Mercadal

Publications and source records attributed to L Mercadal.

At least 19 recordsLinked to original sources
PubMed2006

Analysis of the optical concentration curve to detect access recirculation.

The optical blood volume curve sometimes presents either a positive or a negative rapid and reversible variation (spike) during the step of the dialysate conductivity, automatically set by the monitor for the ionic dialysance (ID) measurement. We studied whether this feature was in relation with access recirculation. Firstly, we studied if the manoeuvre of reversed position of the blood lines created the same feature in the blood volume curve. Secondly, two medical teams systematically checked for the presence of spikes and measured the access recirculation by way of an ultrasound dilution technique. The manoeuvre of reversed position of the blood lines invariably reproduced the same feature on the curve of the optical blood volume measurement in case of a recirculation greater than 20%. In the normal position of the blood lines, the 16 patients with an access recirculation greater than 20% had spikes. Spikes during ID measurement were not constant for an access recirculation between 10 and 20% and did not occur for an access recirculation of less than 10% or an undetectable one. The special spike of the optical blood volume curve occurring during the ID measurement clearly detects access recirculation. The specificity is of 100% when this modification is present all along the dialysis session for all the ID measurements and the sensitivity is 100% when the access recirculation is greater than 20%.

Arteriovenous Shunt, Surgical↗
PubMed2005

[Efficiency of secondary posterior trunk single stimulation, low volume infraclavicular plexus block for upper limb surgery].

OBJECTIVES: To assess the efficiency of a posterior secondary trunk single stimulation, low volume (30 ml 1.5% mepivacaine) infraclavicular brachial plexus block (ICB) technique. STUDY DESIGN: Prospective study. PATIENTS AND METHODS: One hundred consecutive patients scheduled for hand, forearm or elbow surgery were included. ICB was placed using a single stimulation technique. 30 ml 1.5% mepivacaine was injected when an evoked distal radial motor type response was elicited for 0.3-0.6 mA intensity current. Based upon both sensory and motor distribution ICB, characteristics and performance were assessed. RESULTS: No patient required general anesthesia conversion. Success rate was 92%. 8 patients required a total amount of 10 complementary distal troncular blocks. No specific complication of ICB technique was accoutered. All patients completed full neurological recovery from ICB 24 hours after surgery. CONCLUSION: 30 ml mepivacaine 1.5% ICB is suitable for upper limb surgery.

Adult↗
PubMed2005

Tuberculosis after conversion from azathioprine to mycophenolate mofetil in a long-term renal transplant recipient.

We report the third case in the literature of a patient with a long-lasting renal allograft who experienced tuberculosis just after the switch from azathioprine to mycophenolate mofetil. The switch was likely responsible for the reactivation of dormant tuberculosis; prophylactic antituberculous treatment should be considered in cases of such a therapeutic change.

Antitubercular Agents↗
PubMed2005

Electrophysiological response to dialysis: the role of dialysate potassium content and profiling.

UNLABELLED: The task of dialysis therapy is, amongst other things, to remove excess potassium (K+) from the body. The need to achieve an adequate K+ removal with the risk of cardiac arrhythmias due to sudden intra-extracellular K+ gradient advises the distribution of the removal throughout the dialysis session instead of just in the first half. The aim of the study was to investigate the electrical behavior of two different K+ removal rates on myocardial cells (risk of arrhythmia and ECG alterations). Constant acetate-free biofiltration (AFB) and profiled K+ (decreasing during the treatment) AFB (AFBK) were used in a patient sample to understand, first of all, the effect on premature ventricular contraction (PVC) and on repolarization indices [QT dispersion (QTd) and principal component analysis (PCA)]. The study was divided into two phases: phase 1 was a pilot study to evaluate K+ kinetics and to test the effect on the electrophysiological response of the two procedures. The second phase was set up as an extended cross-over multicenter trial in patient subsets prone to arrhythmias during dialysis. Phase 1: PVC increased during both AFB and AFBK but less in the latter in the middle of dialysis (298 in AFB vs. 200 in AFBK). The PVC/h in a subset of arrhythmic patients was 404 +/- 145 in AFB and 309 +/- 116 in AFBK (p = 0.0028). QT interval (QTc) prolongation was less pronounced in AFBK than in AFB. Phase 2: The PVC again increased in both AFB and AFBK but less in the latter mid-way through dialysis (79 +/- 19 AFB vs. 53 +/- 13 AFBK). Moreover, in the most arrhythmic patients the benefit accruing from the smooth K+ removal rate was more pronounced (103 +/- 19 in AFB vs. 78 +/- 13 in AFBK). CONCLUSION: It is not the K+ dialysis removal alone that can be destabilizing from an electrophysiological standpoint, but rather its removal dynamics. This is all the more evident in patients with arrhythmias who benefit from the K+ profiling during their dialysis treatment.

Adult↗
PubMed2002

[ANCA associated glomerulonephritis related to benzylthiouracil].

INTRODUCTION: Vasculitis associated with antineutrophil cytoplasmic antibodies (ANCA) have been reported in patients suffering from Graves' disease treated with anti-thyroid drugs and especially propylthiouracil (PTU). EXEGESIS: We report a case of Graves' disease treated with benzylthiouracil (Basdène). This therapy was complicated by acute renal insufficiency due to crescentic glomerulonephritis associated with pANCA. After benzylthiouracil withdrawal and under corticosteroids, renal insufficiency, biological inflammation and pANCA levels decreased. CONCLUSION: Similar vasculitis associated with pANCA secondary to anti-thyroid drugs, especially propylthiouracil, were described. This suggests a causal relation between drug and vasculitis. To our best knowledge, it is the first case of vasculitis secondary to benzylthiouracil.

Antibodies, Antineutrophil Cytoplasmic↗
PubMed2002

[Nephrotoxicity of amphotericin B].

Amphotericin B is widely used for severe life threatening fungal infections. Its use is limited by a dose-dependent nephrotoxicity manifested by a reduction in glomerular filtration rate and tubular dysfunction. An elevated creatinine associated with amphotericin B is not only a marker for renal dysfunction but is also linked to a substantial risk for the use of hemodialysis and a higher mortality rate; therefore amphotericin B nephrotoxicity is not a benign complication and its prevention is essential. Several manipulations have been proposed to try and minimize amphotericin B induced nephrotoxicity. Systematic hydration is crucial to minimize amphotericin B. Mannitol or intralipids administration were once suggested as protective based on anecdotal observational reports. Small prospective and randomized trials, however did not support a protective effect. Three new formulations have been developed in an attempts to improse both efficacy and tolerability: amphotericin B in lipid complex (ABLC, Abelcet). Colloidal dispersion (ABCD, Amphotec and amphotericin B liposome (Ambisome). Three prospectives randomized studies have clearly shown that Ambisome is less nephrotoxic than amphotericin B. Unfortunately the only randomized trial comparing Abelcet with amphotericin B is an open-label treatment of invasive candidiasis which was presented 5 years ago but never published as a full paper. Furthermore in a recent multicenter double-blind study it has been shown that Ambisome has a better safety profile than Abelcet with less chills/rigors and less nephrotocixity.

Amphotericin B↗
PubMed2000

MR imaging features of acute bilateral renal cortical necrosis.

Bilateral renal cortical necrosis (BRCN) is an uncommon cause of acute renal failure. Kidney biopsy, arteriography, and contrast-enhanced computed tomography (CT) are usually used to diagnose BRCN. However, these methods can have potentially serious side effects. We report two cases in which magnetic resonance imaging (MRI) evidenced characteristic features of BRCN, which were confirmed by histological findings and arteriography and correlated with clinical evolution. In the first case report, the diagnosis of a massive and complete cortical necrosis variety was suggested on MRI that showed a thin rim of low signal intensity along border of kidneys. It was confirmed on kidney biopsy, and the renal function did not recover. The second case is an incomplete form with cortical patchy areas of low signal intensity. In these two patients, MRI helped to establish an early diagnosis of BRCN with characteristic representative findings, without the potential nephrotoxic effects of iodinated contrast that has to be used in CT and arteriography. Kidney biopsy, besides the risks of complications, provides only a parceled analysis of the renal tissue and therefore does not allow any conclusion as to the extension of cortical necrosis. MRI may be of great help for the diagnosis and follow-up of acute renal cortical necrosis.

Adult↗
PubMed2000

Retroperitoneal fibrosis and membranous nephropathy.

We report on a patient with a past history of Pott's abscess who suffered both from a retroperitoneal fibrosis and a membranous glomerulonephritis. Five cases of retroperitoneal fibrosis and immune complex glomerulonephritis are already reported in the literature. These associations might result from a particular systemic immune response to an unknown antigen. Consequently, we consider the role of tuberculosis in our case.

Adult↗
PubMed1999

Determination of access blood flow from ionic dialysance: theory and validation.

BACKGROUND: Several noninvasive techniques have been recently developed for calculating blood flow rate of vascular access in hemodialyzed patients from the on-line measurement of recirculation ratio by injecting a saline bolus when the blood lines are reversed. Here we describe a new noninvasive method based on ionic dialysance measurements without the need of a saline bolus. METHODS: Mathematical modeling allows to calculate blood flow in vascular access (QA) from the recirculation ratio (Rrev) measured when the blood lines are reversed, without the need to stop ultrafiltration, by using the formula: QA = (QB - QF) 1 - Rrev/Rrev where QB is the blood flow at the dialyzer inlet and QF the ultrafiltration rate. Because the ionic dialysance takes recirculation into account, we tested a new method to assess QA from the measurement of ionic dialysance at normal (D) and reverse (Drev) positions of the blood lines for the same QB. Assuming the absence of access recirculation at normal position of the blood lines, mathematical modeling provides the following relationship: QA = (D - QF)Drev/D - Drev. The estimation of QA from measurement of ionic dialysance (QA-ID) was compared in 28 patients to the estimation of QA by ultrasound dilution technique (QA-US). RESULTS: The two methods were strongly correlated (QA-ID = 1.24 * QA-US, r2 = 0.86, P < 0.0001). The difference between QA-ID and QA-US was 107 +/- 387 ml/min (mean +/- SD). CONCLUSIONS: Our method provides a valuable estimation of the vascular access flow and is fully noninvasive, easy to perform (no need of bolus injection and of accurate measurement of QB) and totally inexpensive. Consequently this method is suitable for monitoring access blood flow in hemodialyzed patients in order to predict access thrombosis and to treat significant stenotic lesions before thrombosis.

Blood Circulation↗
PubMed1998

Is ionic dialysance a valid parameter for quantification of dialysis efficiency?

The on-line measurement during hemodialysis of ionic dialysance provides an estimation of urea clearance with a good and already proven correlation. Some discrepancies remain controversial, and the influence of the dialyzer membrane is still being debated. Eighty-eight measurements of ionic dialysance (ID) were performed with a Diascan module (Hospal R&D, Int., Lyon, France), 51 with cellulosic membranes, and 37 with synthetic membranes, chosen according to their surface charges. The ID was compared to the urea clearance (UK) measured from the blood (n=16) and dialysate (n=88) sides. The ID is closely correlated (r=0.91) but significantly (p < 0.01) lower than the UK by 5% (ID/UK=0.95+/-0.06). The correlation is improved by a semilogarithmic regression analysis (r=0.93). Regarding the influence of the membrane charge, a slight difference is only evidenced for UK < 180 ml/min whereby ID is closer to the urea clearance for the charged membranes (ID/UK=0.98+/-0.05 for charged membranes versus 0.95+/-0.05 for noncharged membranes, p < 0.05). The discrepancy between ID and UK could be related with the difference in the blood distribution volume of urea and that of electrolytes. The good correlation provides the major argument for ID being used as a monitoring parameter of the delivered dialysis dose. Having integrated the discrepancy between ID and UK, prescription can be guided by ID for delivering the adequate normalized dialysis dose as defined by Kt/V.

Hemodialysis Solutions↗
PubMed1990

[Severe suicides: short- and long-term outcome. Assessment of their quality of life].

From January 1977 to December 1982, 160 patients (10 to 55 years old) were admitted in a traumatic Intensive Care Unit after serious attempted suicides. Hospital mortality rate was about 34%. A questionnaire was sent to alive patients in 1983 (median delay between attempted suicide and questionnaire: 3.5 years); 68 were alive in 1983, 46 answered to questionnaire, 3 were died (two according to a new suicide); 32 could not be found; 85% of contacted patients answered (they were comparable in age, sex and means used in their suicide attempts, to the others). One patient about two must be rehospitalised one or more times. One patient about two must be always take drugs; 85% worked. Over 50% of the patients considered they had returned to their former way of life but 50% presented increased difficulty to work, and 25% said that they had no sequelae. Any of these 46 patients had made an other attempt suicide.

Adolescent↗
PubMed1990

[Experience of health personnel at an organ procurement center].

Organs' procurement oblige to take care of a great number of brain death patients. This study concerns the psychological influence of such a situation on teams, nurses and physicians of this specific activity of harvesting. It took place in three organs' procurement intensive care units and interested sixty three men and women. These teams reveal the difficulty to live "the brain death", according to brain death patients themselves and their families, but also to transplantation: to work on brain death patients for the life of other patients. So it seem necessary to give a place at a psychologist in this specific intensive care units not for the patients, they are dead, but for the teams.

Adult↗
PubMedDate not supplied

Hemolytic and uremic syndrome after heart transplantation.

Two cases of hemolytic and uremic syndrome in heart transplant recipients are reported. Among solid organ transplantations, this complication mainly occurred in renal transplantation and only 1 case was reported in heart transplantation in the literature. Cyclosporine was the only etiologic factor found. The renal outcome was severe with end-stage renal failure and no recovery of the renal function despite stopping cyclosporine, corticoids and plasma exchange.

Adult↗
PubMedDate not supplied

Neurotoxicity of valacyclovir in peritoneal dialysis: a pharmacokinetic study.

Valacyclovir is an effective oral agent for the treatment of herpes virus infection, however, the pharmacokinetics of the drug are altered in renal failure. It is increasingly recognized that dose adjustment of oral valacyclovir in renal failure is necessary to avoid neurotoxicity. We studied this drug in a continuous ambulatory peritoneal dialysis (CAPD) and immunocompromised patient. She developed neurotoxicity with an adjustment dosage of valacyclovir for a cutaneous zoster infection. The elimination half-time (15 h) was similar to that reported for end-stage renal disease patients, while the steady-state volume of distribution (85 l) and the area under the curve concentration (127 mg/l.h) were greater. The mean CAPD dialysance was only 5.27 ml/min with less than 1% of an administered dose being recovered in the 24-hour dialysate. 48 h after interrupting treatment, she recovered normal neurological status and 500 mg of valacyclovir every 2 days was effective and well tolerated.

Acyclovir↗