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Thierry Petitclerc

Publications and source records attributed to Thierry Petitclerc.

11 recordsLinked to original sources
PubMed2005

Regional citrate anticoagulation during hemodialysis: a simplified procedure using Duocart biofiltration.

BACKGROUND: Regional citrate anticoagulation during hemodialysis is promising, but its clinical implementation is routinely cumbersome because a continuous adjustment of calcium infusion at the dialyzer outlet is needed. Duocart biofiltration (DCB) is a new hemodialysis method using a calcium and magnesium-free dialysate containing only sodium chloride and bicarbonate combined with the infusion into the venous line of a solution containing the ionic complement (K, Ca, Mg) and glucose. Since the dialysate is calcium- and magnesium-free and infusion rate of the solution containing calcium is automatically determined by the dialysis delivery system according to the on-line measured value of ionic dialysance, DCB seems a technique especially suitable for citrate anticoagulation procedure. METHODS: Thirty DCB sessions were performed in 10 patients with increased risk of bleeding. A commercially available mixture of trisodium citrate, citric acid and glucose was infused into the arterial line at a rate equal to 3% of dialyzer blood flow. The ionic complement (K: 48 mM, Ca: 42 mM, Mg: 14 mM, glucose: 110 mM) was infused at a rate equal to 1/24 ionic dialysance value automatically determined each 15 min by the dialysis monitor. DCB sessions were compared to 21 conventional bicarbonate hemodialysis (BHD) sessions with low-molecular-weight heparin anticoagulation. RESULTS: Whole blood activated clotting time (WBACT) measured in the venous line (before infusion of ionic complement) was 200% of the WBACT value in the arterial line. Clotting and citrate-related adverse events were not observed. Postdialysis compression time of the arteriovenous access is significantly (p<0.001) shorter after DCB sessions (3.9+/-1.1 min) compared with BHD sessions (8.7+/-4.6 min). CONCLUSION: Citrate anticoagulation during Duocart biofiltration is effective, safe and suitable for routine use because calcium infusion rate is automatically adjusted without the need of monitoring degree of anticoagulation and level of ionized calcium.

Adult↗
PubMed2005

[Backward flow of blood in the extracorporal circuit pressure transducers of the generator-monitors of hemodialysis].

Transmission of hepatitis C virus between hemodialysis patients occurs mainly between the patients treated simultaneously in the same sector or in the same room. The other mode of viral transmission occurs between two patients treated successively with the same hemodialysis generator-monitor and sharing the same environment. One of the vectors of this last mode of transmission could be the contamination of the system of measurement of pressure of the extracorporal blood circuit. In July 2004, the French health products safety agency (Agence française de sécurité sanitaire des produits de santé, Afssaps) published a recommendation on these systems of measurement of pressure. i) The recommendation points out the optional preventive measures that users and manufacturers can carry out: (a) the manufacturers can propose tight systems of measurement of pressure, based on the deformation of a device; (b) the users can add a second protective filter on the external tubing connecting the blood circuit to the machine; (c) the manufacturers can add additional protective filters on the internal tubings of the machine. ii)The recommendation indicates the actions to be carried out obligatorily in the event of backward flow of blood in the last external protective filter: the soiled filter must be replaced and the causes of the backward flow must be analyzed and corrected; after the session, the monitor must be taken out of the unit and checked by a technician. The technician must replace all the elements located downstream from a soiled protective filter: tubings, drip chamber level control system, and pressure transducer. When these elements are protected by internal filters, only tubings and the first internal filter not soiled must be replaced. Precautions with regard to the systems of measurement of pressure must supplement standard precautions of hygiene essential in hemodialysis units.

Cross Infection↗
PubMed2005

Haemodialysis with on-line monitoring equipment: tools or toys?

BACKGROUND: On-line monitoring of chemical/physical signals during haemodialysis (HD) and bio-feedback represents the first step towards a 'physiological' HD system incorporating adaptive and logic controls in order to achieve pre-set treatment targets. METHODS: Discussions took place to achieve a consensus on key points relating to on-line monitoring and bio-feedback, focusing on the clinical applications. RESULTS: The relative blood volume (BV) reduction during HD can be monitored by optic devices detecting the variations in concentration of haemoglobin/haematocrit. BV changes result from an equilibrium between ultrafiltration and the refilling capacity. However, BV reduction has little power in predicting intra-HD hypotensive episodes, while the combination of the patient-dialysate sodium gradient, the relative BV reduction between the 20th and 40th minute of HD, the irregularity of the profile of BV reduction over time and the heart rate decrease from the start to the 20th minute of HD predict intra-HD hypotension with a sensitivity of 82%, a specificity of 73% and an accuracy of 80%. A bio-feedback system drives the relative BV reduction according to desired values by instantaneously changing the ultrafiltration rate and the dialysate conductivity. This system has proved to reduce the incidence of intra-HD hypotension episodes significantly. Ionic dialysance and the patient's plasma conductivity can be calculated easily from on-line inlet and outlet dialysate conductivity measurements at two different steps of dialysate conductivity. Ionic dialysance is equivalent to urea clearance corrected for recirculation and is a tool for continuously monitoring the dialysis efficiency and detecting early problems with the delivery of the prescribed dose of dialysis. Given the strict and linear relationship between conductivity and sodium content, the conductivity values replace the sodium concentration values and this permits the development of a conductivity kinetic model, by means of which sodium balance can be achieved at each dialysis session. The conductivity kinetic model has been demonstrated to improve intra-HD cardiovascular stability in hypotension-prone patients significantly. Ionic dialysance is also a useful tool to monitor vascular access function, as it can be used to obtain serial measurements of vascular access blood flow. On-line urea monitors provide detailed information on intra-HD urea kinetics and delivered dialysis dose, but they are not in widespread use because of the costs related to the disposable materials (e.g. urease cartridge). The body temperature monitor measures the blood temperature at the arterial and venous lines of the extra-corporeal circuit and, thanks to a bio-feedback system, is able to modulate the dialysate temperature in order to influence the patient's core body temperature, which can be kept at constant values. This is associated with improved intra-HD cardiovascular stability. The module can also be used to quantify total recirculation. CONCLUSIONS: On-line monitoring devices and bio-feedback systems have evolved from toys for research use to tools for routine clinical application, particularly in patients with clinical complications. Conductivity monitoring appears the most versatile tool, as it permits quantification of delivered dialysis dose, achievement of sodium balance and surveillance of vascular access function, potentially at each dialysis session and without extra cost.

Biofeedback, Psychology↗
PubMed2005

Ionic dialysance: principle and review of its clinical relevance for quantification of hemodialysis efficiency.

Ionic dialysance (D) is an online measured variable now available on several dialysis monitors to evaluate small-solute clearance. Based on conductivity measurements in the inlet and outlet dialysate, the principle of the measurement and the different measurement methods are described. Studies that have evaluated the reliability of ionic dialysance to assess dialysis efficiency are discussed. These studies are divided into two groups: the first comparing ionic dialysance to urea clearance and the second comparing Dt/V to Kt/V(urea), in which the uncertainties of the measurement of V(urea) could have misrepresented the relationship between Dt/V and Kt/V(urea). When Kt/V(urea) via the Daugirdas second-generation equation taking the rebound into account is considered, slight-even nonsignificant-differences are evidenced between Kt/V(urea) and Dt/V. Therefore, ionic dialysance should be considered as a valid measure in future guidelines for dialysis efficiency.

Autoanalysis↗
PubMed2005

Effect of mineralocorticoids on interdialytic weight gain in hemodialysis patients with perdialytic hypotension.

Fludrocortisone is recommended in patients with orthostatic hypotension and a benefit has been suggested in hemodialysis patients with severe hypokaliemia. We report 2 patients who suffered from chronic severe perdialytic hypotension resistant to midodrine and who were treated in a long-term period with fludrocortisone. A rise of post-dialytic BP was observed with a decrease of the interdialytic weight gain (IWG). We suggest that the IWG decrease is induced by a lessening of the renin angiotensin aldosterone system that could be less stimulated at the end of the dialysis session because of a better-preserved arterial pressure. The decrease of angiotensin could lessen the feeling of thirst.

Adrenergic alpha-Agonists↗
PubMed2004

Dialysis dose and frequency.

BACKGROUND: From the beginning of the dialysis era, the issue of optimal dialysis dose and frequency has been a central topic in the delivery of dialysis treatment. METHODS: We undertook a discussion to achieve a consensus on key points relating to dialysis dose and frequency, focusing on the relationships with clinical and patient outcomes. RESULTS: Traditionally, dialysis adequacy has been quantified referring to the kinetics of urea, taken as a paradigm of all uraemic toxins, and applying the principles of pharmacokinetics using either single- or double-pool variable volume models. An index of dialysis dose is the fractional clearance of urea, which is commonly expressed as Kt/V. It can be calculated from blood urea concentration and haemodialysis (HD) parameters, according to the respective urea kinetic model or by means of simplified formulas. Similar principles are applicable to peritoneal dialysis (PD), where weekly Kt/V and creatinine clearance are used. Recommended minimal targets for dialysis adequacy have been defined by both American and European guidelines (DOQI and European Best Practice Guidelines, respectively). The question of how to improve the severe outcome of dialysis patients has recently come back to the fore, since the results of two recent randomized controlled trials led to the conclusion that, in thrice weekly HD and in PD, increasing the dialysis dose well above the minimum requirements of current American guidelines did not improve patient outcome. Daily HD (defined as a minimum of six HD sessions per week), in the form of either short daytime HD or long slow nocturnal HD, is regarded as a possibility to improve dialysis patient outcome. The results of the studies published so far indicate excellent results with respect to all outcomes analysed: optimal blood pressure control, regression of left ventricular hypertrophy and amelioration of left ventricular performance, improvement of renal anaemia, optimal hyperphosphataemia control, improvement of nutritional status, reduction in oxidative stress indices and improvement in quality of life. The basis for these beneficial effects is thought to be a more physiological clearance of solutes and water, with reduced pre- and post-HD solute concentrations and interdialytic oscillation, compared with traditional HD. Apart from concerns regarding reimbursement and organizational issues, no serious adverse effects have been described with daily HD. However, the evidence accumulated is limited mainly to retrospective cohorts, with small patient numbers and no adequate controls in most instances. Therefore, large prospective studies with adequate controls are required to make daily HD accepted by reimbursing authorities and patients. CONCLUSIONS: Given the available observational and interventional body of evidence, there is no reason to reduce arbitrarily dialysis dose, particularly dialysis treatment time in HD patients treated three times weekly. Daily HD represents a very promising tool for improving dialysis outcomes and quality of life, although its impact on patient survival has not yet been proven definitively.

Biomarkers↗
PubMed2004

End-stage renal failure and cardiac mortality after heart transplantation.

BACKGROUND: Coronary artery disease (CAD) is the leading cause of mortality after the first year of heart transplantation. End-stage renal failure (ESRF) is more frequent because of long-term survival. Impact of ESRF on cardiac mortality in heart transplant patients is unappreciated. The hypothesis of accelerated CAD in uremic patients has been suggested. METHODS: In Pitié La Salpêtrière hospital, 1211 heart transplants have been performed between 1982 and 2001. Thirty-three patients have reached ESRF. A case-control study was performed to identify risk factors responsible for ESRF and to appreciate the impact of ESRF on cardiac mortality. RESULTS: In cases at 6 months, serum creatinine tended to be higher (159 +/- 31 micromol/L vs. 141 +/- 44 micromol/L, p = 0.06) and cyclosporine (CSA) dosage (mg/kg) was significantly lower (5.4 +/- 1.8 mg/kg vs. 7.7 +/- 2.7 mg/ kg, p = 0.002). Mean triglyceride level after transplantation until dialysis was significantly lower in cases (2.18 +/- 0.82 mmol/L vs. 1.48 +/- 0.62 mmol/L, p = 0.002). In cases and controls, cardiac mortality was responsible for 67% (10 of 15) and 38% (three of eight) of all deaths, respectively. High triglyceride level (> or = 2 mmol/L) was associated with cardiac mortality [p < 0.03, hazard ratio (HR) = 3.89]. Kaplan Meier cardiac free survival rates were significantly lower in cases than in controls (p < 0.03). CONCLUSION: These data suggest that CSA nephrotoxicity could result from individually determined susceptibility and that hypertriglyceridemia may have a negative impact on renal function and cardiac mortality. The risk of cardiac mortality is increased in heart transplant patients with ESRF. The hypothesis of accelerated atherosclerosis in ESRF patients after heart transplantation leading to higher cardiac mortality incidence needs further study.

Adult↗
PubMed2002

Angiotensin-converting enzyme inhibitor-induced syndrome of inappropriate secretion of antidiuretic hormone: case report and review of the literature.

Seventeen cases of severe hyponatremia induced by angiotensin-converting enzyme (ACE) inhibitor therapy have been reported in the literature. The mechanism of severe hyponatremia induced by ACE inhibitor is not clear. A 60-year-old white man with a history of idiopathic dilated cardiomyopathy was treated with enalapril, 20 mg daily, that had been started 2 weeks before heart transplantation. The serum sodium level was 138 mmol/L before initiation of enalapril therapy and 127 mmol/L just before cardiac surgery. In the post-heart transplantation period, enalapril therapy was withdrawn for the perianesthesia period, and the serum sodium level increased from 127 to 140 mmol/L. One month later, viral myocarditis developed in the patient and enalapril was reintroduced at 20 mg daily. Two weeks later, natremia decreased. Enalapril was discontinued. Three days later the serum sodium level rose to 140 mmol/L. Severe symptomatic hyponatremia induced by the syndrome of inappropriate secretion of antidiuretic hormone should be considered a rare but possible complication associated with ACE inhibitor therapy.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2002

Ionic dialysance vs urea clearance in the absence of cardiopulmonary recirculation.

BACKGROUND: Several studies have shown a slight discrepancy between ionic dialysance (D) and dialyser urea clearance (UK), even in the absence of access recirculation. As it has been suggested that this discrepancy could be due to the cardiopulmonary recirculation, we studied the relationship between these two parameters in a particular dialysis setting without cardiopulmonary recirculation. METHODS: Paired measurement of urea clearance and ionic dialysance were performed in five patients without arterio-venous access who were dialysed via an internal jugular vein twin catheter. Fifty paired measurements were used for statistical analysis. Vascular access recirculation was assessed by an ultrasound dilution technique. The measured value of ionic dialysance was corrected (D(0)) for the effect of vascular access recirculation and was compared with instant urea clearance calculated from the dialysate side. RESULTS: The difference between the paired measurements of D(0) and UK (n=50) was equal to 0.6+/-16.9 ml/min (NS). With a statistical power of 90% and taking into account this standard deviation, this study might have shown a difference of at least 10.9 ml/min. The correlation was highly significant (P<0.0001). The discrepancy of the two parameters varied with dialysis efficiency, with a decreasing D(0):UK ratio for the higher dialysis efficiency. CONCLUSIONS: Compared with our previous results obtained in patients dialysed on arterio-venous access and performed with similar methods, the relationship between D(0) and UK is modified. This difference between D(0) and UK gets lower in patients dialysed on central catheters and this variance is in accordance with that expected when the influence of the cardiopulmonary recirculation on the measurement of ionic dialysance is taken into account. The limits of agreement (+/-2 SD) between D(0) and UK (+/-34 ml/min, Bland-Altman analysis) were higher than expected and raised questions about the accuracy of the measurement of each parameter via a central venous catheter.

Arteriovenous Shunt, Surgical↗
PubMed2002

Detection of vascular access stenosis by measurement of access blood flow from ionic dialysance.

BACKGROUND/AIM: The measurement of the vascular access blood flow rate (Q(a)) in chronic hemodialyzed patients was proposed to predict access thrombosis. We have recently presented a new method based on the measurements of ionic dialysance at normal and reversed positions of the blood lines. We evaluate the reliability of the measurement of Q(a) by this method in detecting significant access stenoses. METHODS: Twenty-five patients on chronic hemodialysis and having a vascular access cannulated with two needles were studied. The Q(a) was evaluated by the Diascan ionic dialysance (Q(a-id)) method and by the ultrasound dilution technique (Q(a-us); Transonic) during the same dialysis session. The measurements were available for 23 patients. In addition, the patients had ultrasonography of their fistula followed by angiography, if a stenosis was detected. RESULTS: Q(a-id) and Q(a-us) were not significantly different, showing a difference in Q(a) at 32 +/- 469 ml/min. Q(a-id) was significantly different between patients with or without stenosis (508 +/- 241 vs. 1,125 +/- 652 ml/min, p < 0.05). Among patients with a Q(a) <500 ml/min by Q(a-id), 5 had a stenosis detected by ultrasonography (sensitivity 83%), and 3 had no stenosis (false-positive rate 18%). Of these 3 patients, 2 had a thrombotic event at 1 and 3 months, suggesting that a more sensitive detection of stenosis for this range of Q(a) is needed and that a Q(a) <500 ml/min has a higher power to predict thromboses than a stenosis by ultrasonography. CONCLUSIONS: The measurement of the access flow rate by the Q(a-id) method has a clinical relevance to the detection of vascular access stenosis. An intervention program based on the Q(a-id) has to be evaluated.

Arterio-Arterial Fistula↗