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Martine Leblanc

Publications and source records attributed to Martine Leblanc.

At least 19 recordsLinked to original sources
PubMed2004

Phosphate addition to hemodiafiltration solutions during continuous renal replacement therapy.

OBJECTIVE: Hypophosphatemia often occurs during continuous renal replacement therapy (CRRT). The addition of phosphate to dialysate and replacement solutions facilitates phosphate handling, but the risk of precipitation with calcium within these solutions has not been addressed. DESIGN AND SETTING: Experimental study with a retrospective observational study in a medico-surgical intensive care unit. METHODS AND PATIENTS: We tested the addition of phosphate to calcium-rich lactate- and bicarbonate-based solutions (Hemosol LG2 and Hemosol B0) used in CRRT to see whether precipitation occurs. Two milliliters of potassium phosphate added to 5-l bags gives a physiological phosphate concentration of 1.2 mmol/l. In addition, calcium and phosphate homeostasis was retrospectively evaluated in 20 consecutive CRRT patients where potassium phosphate had been added to these solutions. MEASUREMENTS AND RESULTS: Total and ionized calcium, phosphate, pH, PCO(2) and bicarbonate remained essentially unchanged 5 h after the addition of 2 ml of potassium phosphate to 5-l Hemosol solutions. Visual inspection did not reveal any precipitate. Of the 20 patients studied, 14 received more than 24 h of phosphate supplementation to dialysate and replacement solutions. Phosphate remained stable throughout CRRT despite phosphate intake from nutrition in 11 cases. No adverse event was noted on potassium, calcium, pH and bicarbonate homeostasis. CONCLUSIONS: The addition of phosphate to Hemosol solutions does not precipitate with the calcium within these solutions. This practical method effectively prevents hypophosphatemia in CRRT patients.

Aged↗
PubMed2004

Continuous renal replacement therapy after cardiac surgery. Review of 85 cases.

BACKGROUND/AIMS: To evaluate the outcome of patients who require continuous renal replacement therapy (CRRT) following cardiac surgery. METHODS: All patients who received CRRT after cardiac surgery over more than 4 years at the Surgical Intensive Care Unit of the Montreal Heart Institute were reviewed. Among 5,564 consecutive patients, 85 underwent CRRT postoperatively. RESULTS: The mean delay between surgery and CRRT initiation was 5 days, and the duration of CRRT was 9 days, without a difference between survivors and non-survivors. Delivered clearances with CRRT were estimated at 25-28 ml/min (approximately 40 liters/day), 29-32 ml/min (approximately 46 liters/day) and 17 ml/min (approximately 25 liters/day) for continuous veno-venous hemofiltration, continuous veno-venous hemodiafiltration and continuous veno-venous hemodialysis, respectively. In-hospital mortality was 43.5%. No difference in mortality was observed between patients with normal renal function at baseline and those with pre-operative renal dysfunction. Mortality was 33.3% after a coronary artery bypass graft (CABG), 57.1% after CABG and valve surgery, 60% after valve surgery, and 72.7% for redo-CABG or redo-valve surgery. 79% of survivors and 86% of non-survivors had received a cardiopulmonary bypass (p = NS). The Simplified Acute Physiology Score II upon intensive care unit (ICU) admission and the requirement of an intra-aortic balloon pump were higher in non-survivors (p < 0.05). The mean length of ICU and hospital stay was 27.4 and 34.2 days for survivors and 17.9 and 22.3 days for non-survivors, respectively (p < 0.05). CONCLUSIONS: Renal impairment is relatively common after cardiac surgery. The mortality of patients who required CRRT after cardiac surgery was 43.5% and was particularly influenced by the type of surgery.

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PubMed2004

Continuous renal replacement therapy after heart transplantation.

BACKGROUND: Renal failure following heart transplantation carries a poor prognosis. The objectives of this study were to determine risk factors for renal failure requiring continuous renal replacement therapy (CRRT), to describe the management strategies regarding immunosuppressive therapy and to examine the short-term prognosis. METHODS: Fifty-six patients who underwent heart transplantation from 1998 to 2002 at the Montreal Heart Institute were retrospectively analyzed. RESULTS: Six of 56 patients (11%) underwent CRRT after heart transplantation. Patients who underwent CRRT had lower preoperative creatinine clearance than those who did not (median 44 versus 59 mL/min, P=0.04) and lower first two-week postoperative creatinine clearance (median 23 versus 42 mL/min, P<0.01) compared with patients without CRRT. The total duration of CRRT ranged between two and 60 days (median 15 days). Cyclosporine was withheld for 12 days versus two days (P<0.01) and the time to achieve therapeutic levels of cyclosporine averaged 18 days versus nine days (P=0.01) among CRRT versus non-CRRT patients. Patients were administered thymoglobulin or basiliximab during cyclosporine withholding. The time to discharge from hospital after transplantation was longer in patients with CRRT (median 47 days versus 17 days, P<0.01). There was no mortality at three months in the CRRT group. CONCLUSION: Creatinine clearance is an important predictor of renal failure requiring renal replacement therapy. Although renal failure remains a serious complication after transplantation, the use of CRRT and antilymphocyte agents during cyclosporine A withholding is associated with a favourable short-term prognosis following heart transplantation.

Acute Kidney Injury↗
PubMed2004

Acid-base balance in acute renal failure and renal replacement therapy.

The approach to acid-base balance based on the concept of strong ions, initially proposed by Stewart, is briefly overviewed. The anion gap and the strong anion gap are both discussed. Comments are made on the strong ion difference of fluids administered to patients and their impact on acid-base status will be commented. Renal failure patients have an altered acid-base balance; most commonly, a mixed type of metabolic acidosis (hyperchloraemic, and of a high anion gap) is observed. The consequences of renal metabolic acidosis are described. Finally, the impact of renal replacement therapy on acid-base balance is exposed; different modalities of renal replacement are considered in regard to their alkalinizing performance.

Acid-Base Equilibrium↗
PubMed2003

Intravenous phosphate in the intensive care unit: more aggressive repletion regimens for moderate and severe hypophosphatemia.

OBJECTIVE: To evaluate efficacy and safety of aggressive correction of hypophosphatemia with intravenous potassium phosphate in the ICU. DESIGN AND SETTING: Randomized interventional prospective study in the medical and surgical ICU of a tertiary university hospital. PATIENTS: Critically ill patients with hypophosphatemia between June and November 1998. MEASUREMENTS AND RESULTS: Patients with moderate hypophosphatemia (<0.65 and >0.40 mmol/l; n=37) were randomized into two groups: group 1 received 30 mmol potassium phosphate intravenously in 50 ml saline over 2 h, and group 2 received 30 mmol potassium phosphate in 100 ml saline over 4 h. Patients with severe hypophosphatemia (<0.40 mmol/l; n=10) were also randomized into two groups: group 3 received 45 mmol potassium phosphate intravenously in 100 ml saline over 3 h, and group 4 received 45 mmol potassium phosphate in 100 ml saline over 6 h. Electrolytes, blood gas, renal function were monitored until day 3; urine was collected during and until 6 h after infusions. The overall efficacy of the protocols was 98% by the end of the infusion. There was no statistical difference in phosphate values between groups at the end of infusion or at 24 h. No adverse events were noted; one patient had an increase in serum potassium to 6.1 mmol/l. Phosphaturia in all groups was elevated as evidenced by fractional excretion above 20%. CONCLUSIONS: More rapid administration of large potassium phosphate boluses is effective and safe for correcting hypophosphatemia in ICU patients with preserved renal function if baseline serum potassium is below 4 mmol/l.

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PubMed2003

A novel citrate anticoagulation regimen for continuous venovenous hemodiafiltration.

OBJECTIVE: Validation of a novel citrate anticoagulation regimen for continuous venovenous hemodiafiltration (CVVHDF). DESIGN AND SETTING: Prospective cohort trial in medicosurgical intensive care units of two university-affiliated teaching institutions. PATIENTS: Participants were patients at high risk for bleeding, with renal failure requiring CVVHDF without heparin. Fourteen patients completed the study. INTERVENTION: A convection-based citrate anticoagulation CVVHDF regimen using an isotonic replacement fluid containing citrate administered in predilution. A neutralizing solution of calcium chloride and magnesium sulfate was infused at the end of the circuit. Blood flow rate was set and kept at 125 ml/min, and the flow rate of the replacement fluid was initiated at 1250 ml/h and adjusted thereafter according to the monitoring of blood activated coagulation time (ACT), with a target between 180 to 220 s. MEASUREMENTS AND RESULTS: The average filter time-life was 44 h. Thrombosis of the proximal portion of the circuit (which was not anticoagulated) was the main reason for technique failure. A mean urea clearance of 21 ml/min was obtained. Electrolytes and acid-base balance were both well maintained. Six percent (16/287) of Ca(i) readings less than 0.3 mmol/l were associated with very high ACT levels (>300 s). CONCLUSIONS: This regimen is shown to be safe, efficacious, and convenient. Citrate anticoagulation should be monitored using postfilter ACT and/or ionized calcium with respective targets of 200-250 s or 0.3-0.4 mmol/l.

Anticoagulants↗
PubMed2003

Solute clearances during continuous venovenous haemofiltration at various ultrafiltration flow rates using Multiflow-100 and HF1000 filters.

BACKGROUND: In continuous venovenous haemofiltration (CVVH), high ultrafiltration rates provide survival benefits in acute renal failure. This study measured clearances obtained at ultrafiltration rates of up to 4.5 l/h. METHODS: Clearances of small solutes (urea, creatinine, phosphate and urate) and of beta(2)-microglobulin (beta(2)-M) were measured during CVVH. Five preset Multiflow-100 (M-100) and five HF1000 hollow-fibre filters were compared. For the M-100, clearances obtained by haemofiltration were compared with those obtained by haemodiafiltration at similar total effluent rates from a previous study. RESULTS: For small solutes, the effluent to plasma ratio (E/P) remained close to 1.0 at all ultrafiltration rates; filter clearances were thus equal to Quf for both filters. Increasing Quf from 1.0 to 4.5 l/h did not significantly modify E/P. Convective clearances of beta(2)-M were lower than those obtained for small solutes. For the M-100, average beta(2)-M E/P was 0.62+/-0.10 and did not significantly change while increasing Quf. For the HF1000, average beta(2)-M E/P were significantly lower compared with the M-100 (0.42+/-0.09 at 1.0 l/h) and decreased progressively to 0.26+/-0.06 while increasing Quf to 4.5 l/h. With pre-dilution, progressive decreases in clearances delivered to patients were observed reaching 40% at a Quf rate of 4.5 l/h. There was no clinically significant adsorption of beta(2)-M. For the M-100, at similar total effluent flow rates, clearances delivered to patients using haemodiafiltration were significantly higher for small solutes but lower for beta(2)-M in comparison to haemofiltration only. CONCLUSIONS: Filter clearance for small solutes equalled Quf at evaluated rates. At high ultrafiltration rates there was significant loss of clearances with pre-dilution. At similar total effluent rates with the use of pre-dilution, haemodiafiltration is superior to haemofiltration for small solute clearance but inferior for beta(2)-M.

Acute Kidney Injury↗
PubMed2003

Atheroembolic renal failure requiring dialysis: potential for renal recovery? A review of 43 cases.

AIMS: Our objectives were to review the characteristics of patients who developed atheroembolic renal disease requiring dialysis as well as their renal function recovery and survival rates. METHODS: All cases of atheroembolic disease with renal failure severe enough to require dialysis were reviewed from January 1984 to December 2000 in two centers. The diagnosis of atheroemboli was based on clinical presentation and/or biopsy. Acute renal failure was defined as a serum creatinine >200 micromol/l if normal at baseline or doubling from baseline if chronic renal failure, whereas renal function recovery was the ability to discontinue renal replacement therapy for >or=3 months. RESULTS: Forty-three cases were identified (37 males and 6 females; mean age 67 +/- 5 years); the average time to acute renal failure and to diagnosis was similar at 36 days. The majority of patients had at least one precipitating factor identified (58% coronary angiography, 26% angiography, 16% vascular surgery, 2% anticoagulation); 1 had a spontaneous presentation whereas 7 had more than one factor. More than 90% had underlying hypertension and chronic renal dysfunction with a baseline creatinine of 195 +/- 81 micromol/l, approximately 80% had coronary artery disease, 80% were smokers, 60% had a history of abdominal aorta aneurysm, >50% presented with intermittent claudication, and 56% were anticoagulated at the time of the event. Most patients were nonoliguric (80%), had increased hypertension (71%), blue toes (67%), livedo reticularis (52%), whereas abdominal pain and central nervous system symptoms were present in 33 and 7% of the cases, respectively. Eosinophilia was found in 88%, while hypocomplementemia was present in less than 15%. When compared to the 12 patients with recovery of renal function (after a mean delay of 409 +/- 336 days), the 31 patients who did not recover function presented with more severe intermittent claudication and underlying chronic renal dysfunction (p < 0.05). Indeed, the only variable found to unfavorably influence renal function recovery was the presence of intermittent claudication. Patients were mainly treated by intermittent hemodialysis except for 5 (2 on CRRT and 3 on peritoneal dialysis). Renal function recovery was associated with a higher chance of survival; 33% of patients died in the first year after diagnosis. CONCLUSION: Atheroembolic renal disease carries a high mortality rate reflective of the extensive cardiovascular disease of affected patients; nevertheless, the potential for renal function recovery appears greater than for other vascular causes of renal failure.

Acute Kidney Injury↗
PubMed2002

Quinine pharmacokinetics in chronic haemodialysis patients.

AIMS: Quinine is often used to prevent muscle cramps in patients with chronic renal failure. A standard dose of 300 mg at bedtime is usually recommended, but little is known about the pharmacokinetics of quinine in the presence of renal failure. METHODS: We studied the pharmacokinetics of quinine in eight normal subjects and eight patients with chronic renal failure on haemodialysis after a single oral dose of quinine sulphate (300 mg). RESULTS: The concentration of alpha1-acid glycoprotein (AAG), the major binding protein for quinine, was increased in haemodialysis patients compared with control subjects (1.52 g l-1 vs 0.63 g l-1 [mean difference 1.033; 95% CI 0.735, 1.330]) whereas albumin levels were decreased (30 g l-1 vs 40 g l-1 [mean difference 9.5; 95% CI 3.048, 15.952]). Accordingly, the free fraction of quinine was decreased (0.024 vs 0.063 [mean difference 0.0380; 95% CI 0.0221, 0.0539]) and the apparent volume of distribution tended to decrease (0.95 l kg-1 vs 1.43 l kg-1 [mean difference 0.480; 95% CI 0.193, 1.154]). The quinine binding ratio correlated with the plasma concentration of AAG but not that of albumin. The clearance of free (unbound) quinine was increased in haemodialysis patients compared with controls (67.9 ml min-1 kg-1 vs 41.1 ml min-1 kg-1 [mean difference -26.8; 95% CI, -56.994, 3.469]), and the area under the curve (AUC) of the two main metabolites, 3-hydroxyquinine and 10,11-dihydroxydihydroquinine were increased. CONCLUSIONS: In patients with chronic renal failure, there is an increase in plasma protein binding and in the clearance of free drug, resulting in lower plasma concentration of free quinine.

Administration, Oral↗
PubMed2002

Prospective evaluation of the intra-access flow of recently created native arteriovenous fistulae.

BACKGROUND: The aim of this study is to assess the evolution of intra-access flow (Q(ac)) in recently created native arteriovenous fistulae (AVFs) during the first few months of use. METHODS: All AVFs were monitored by means of ultrasound dilution using Transonic (Transonic Systems Inc, Ithaca, NY). First Q(ac) measurements were obtained between 6 to 10 weeks after creation and subsequently every 3 to 6 weeks during the following 4 months. Per routine, AVFs are cannulated 6 weeks after their creation in our unit. Fifty-seven patients with new AVFs were initially enrolled, but 12 patients were lost at follow-up. There was a 69% to 31% ratio of brachiocephalic (BC) to radiocephalic (RC) AVFs, and diabetes affected an equal proportion of patients in both subtypes. RESULTS: Mean initial and final Q(ac)s were 1,132 +/- 681 and 1,097 +/- 644 mL/min, respectively; there was no significant difference during the study period. However, the Q(ac) of BC AVFs remained approximately twice as high as the Q(ac) of RC AVFs during the observation period (initial Q(ac), 1,336 +/- 689 versus 645 +/- 332 mL/min; final Q(ac), 1,285 +/- 652 versus 647 +/- 331 mL/min, respectively). Male sex was associated with a greater Q(ac) throughout the evaluation (1,263 +/- 754 versus 852 +/- 375 mL/min for women). No significant difference was noted between different age groups, and diabetes did not significantly affect Q(ac). Finally, the initial Q(ac) of a BC AVF was influenced by the presence of a previously functioning RC AVF on the same arm. The initial Q(ac) in BC AVFs was 1,800 +/- 919 mL/min in that subgroup (and decreased to 1,302 +/- 733 mL/min by the end of the study, therefore becoming similar to the mean Q(ac) of other BC AVFs). CONCLUSION: From these results, we conclude that newly created native AVFs have an initial Q(ac) that does not vary significantly during the first 6 months and may already be maximal at 6 weeks or at the time of first needle puncture in our hands. Among demographic factors, sex influences the Q(ac) of native AVFs, whereas age and diabetes do not.

Aged↗
PubMed2002

The Acute Dialysis Quality Initiative--part IV: membranes for CRRT.

The extracorporeal membrane used in a continuous renal replacement therapy (CRRT) for the treatment of a critically ill patient with acute renal failure (ARF) is vitally important for several reasons, including its influence on biocompatibility and filter performance. The clinical relevance of membrane-related biocompatibility markers traditionally used in chronic hemodialysis remains unclear in CRRT. Numerous approaches may be used to assess membrane and filter performance in CRRT, but no specific methodology is accepted widely at present. Although a potential benefit of certain membranes used for CRRT is adsorptive removal of inflammatory mediators, this issue has not been assessed carefully in well-designed clinical trials. These and other issues should be the subject of future clinical research efforts.

Acute Kidney Injury↗
PubMed2002

The Acute Dialysis Quality Initiative--part VII: fluid composition and management in CRRT.

Fluid composition and management are important parts of continuous renal replacement therapy (CRRT). Most commercially available CRRT solutions are able to reestablish electrolyte homeostasis provided some phosphate supplementation is given. Supraphysiologic glucose concentrations should be avoided. Predilution fluid replacement allows higher ultrafiltration rates and can be considered as an adjunct to the anticoagulation regimen. Lactate is an effective buffer in most CRRT patients. Bicarbonate is preferred in patients with lactic acidosis and/or liver failure. When citrate is used as anticoagulant, frequent monitoring of pH is required. The clinical consequences of CRRT-induced decreases of body temperature are not clear. Substitution fluid should be sterile, but the bacteriologic requirements for CRRT dialysate are less clear. There is no consensus on the optimal parameters to monitor fluid management. Integrated balancing systems have theoretical advantages over adaptive use of intravenous fluid pumps. Although there is evidence that volume overload is associated with adverse outcome, there is no evidence that fluid removal per se improves outcome in critically ill patients with or without acute renal failure.

Buffers↗
PubMed2002

Acute renal failure in bone marrow transplant patients admitted to the intensive care unit.

BACKGROUND/AIMS: Review of bone marrow transplant (BMT) cases admitted to our intensive care unit (ICU) and to compare co-morbidity and outcome of BMT patients developing or not developing acute renal failure (ARF). METHODS: A case review of BMT patients admitted to the ICU (a 16-bed medico-surgical ICU in a tertiary care teaching institution) over a 4-year period. RESULTS: Between January 1994 and December 1998, 57 among 441 BMT patients (12.9%) were admitted to the ICU, mainly for respiratory distress (58%) and hypotension (32%). Forty-two patients (73.7%) presented ARF as defined as a doubling of serum creatinine. Compared to the 15 other patients, ARF patients had a higher APACHE II score (30 +/- 8 vs. 25 +/- 7, p < 0.05). For ARF vs. non-ARF patients, there was no difference in age (43.8 +/- 10.8 vs. 44.3 +/- 11.1 years), in requirement for mechanical ventilation (76 vs. 73%) and vasopressors (69 vs. 60%), and in prevalence of graft-versus-host disease (19 vs. 13%) or neutropenia (69 vs. 67%), but the prevalence of sepsis (83 vs. 60%) and liver failure (69 vs. 40%) was higher. Maximum serum bilirubin was markedly increased in ARF compared to non-ARF patients (p < 0.005). For both subgroups, no difference in the administration of potential nephrotoxic agents was identified. Usually, ARF was considered multifactorial by clinicians, with ATN being the most frequent diagnosis (55%). Maximum serum creatinine reached a mean of 330 +/- 130 micromol/l. In 74% of cases, ARF occurred concomitantly or after admission to the ICU. Oligoanuria was present in 38%, whereas polyuria was observed in 17%. Fourteen ARF patients (33%) required dialytic support. Mortality rates were significantly different in ARF vs. non-ARF patients (88 vs. 60%, p < 0.05). Predictive factors for the development of ARF were liver failure (odds ratio (OR) 5.9), low serum albumin (OR 1.2) and APACHE II score (OR 1.1), whereas variables predictive of mortality were mechanical ventilation (OR 14.8), ARF (OR 5.8), liver failure (OR 3.7), and APACHE II score (OR 1.2). CONCLUSIONS: This study confirms that ARF in BMT patients admitted to the ICU is frequent, multifactorial, related to liver failure, and that its development has a negative impact on outcome.

Acute Kidney Injury↗