Biomedical subjects

Marc Dorval

Publications and source records attributed to Marc Dorval.

4 recordsLinked to original sources

PubMed2006

Prevention of catheter lumen occlusion with rT-PA versus heparin (Pre-CLOT): study protocol of a randomized trial [ISRCTN35253449].

BACKGROUND: Many patients with end-stage renal disease use a central venous catheter for hemodialysis access. A large majority of these catheters malfunction within one year of insertion, with up to two-thirds due to thrombosis. The optimal solution for locking the catheter between hemodialysis sessions, to decrease the risk of thrombosis and catheter malfunction, is unknown. The Prevention of Catheter Lumen Occlusion with rt-PA versus Heparin (PreCLOT) study will determine if use of weekly rt-PA, compared to regular heparin, as a catheter locking solution, will decrease the risk of catheter malfunction. METHODS/DESIGN: The study population will consist of patients requiring chronic hemodialysis thrice weekly who are dialyzed with a newly inserted permanent dual-lumen central venous catheter. Patients randomized to the treatment arm will receive rt-PA 1 mg per lumen once per week, with heparin 5,000 units per ml as a catheter locking solution for the remaining two sessions. Patients randomized to the control arm will receive heparin 5,000 units per ml as a catheter locking solution after each dialysis session. The study treatment period will be six months, with 340 patients to be recruited from 14 sites across Canada. The primary outcome will be catheter malfunction, based on mean blood flow parameters while on hemodialysis, with a secondary outcome of catheter-related bacteremia. A cost-effectiveness analysis will be undertaken to assess the cost of maintaining a catheter using rt-PA as a locking solution, compared to the use of heparin. DISCUSSION: Results from this study will determine if use of weekly rt-PA, compared to heparin, will decrease catheter malfunction, as well as assess the cost-effectiveness of these locking solutions.

Bacteremia↗

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↗

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↗

PubMedDate not supplied

[Comparative study of two teaching methods of a predialysis educational program].

The purpose of this quasi-experimental study was to compare two teaching methods of a predialysis educational program, namely on-site and by distance. This program was offered to patients with chronic kidney disease (CKD) stage 3. The experimental group one received the on-site program, whereas the experimental group two received the teaching program by distance. This study uses a pre-test post-test design. Measures included a Sociodemographic Information Form, the Degree of Knowledge Integration (Aucoin-Gallant, 1998), and the Knowledge Satisfaction Scale (Aucoin, 1998). In this study, both groups are homogenous from a sociodemographic perspective and have similar creatinine clearance values. Findings demonstrate an increase with knowledge integration and satisfaction with knowledge that is statistically significant for both groups of subjects. Participants in group two learned as much as participants in group one. This study highlights that knowledge integration leads to satisfaction in both groups of subjects. The results demonstrate that predialysis teaching delivered on-site or by distance promotes knowledge integration for patients with CKD stage 3.

Aged↗