Biomedical subjects

Soumaya El Rouby

Publications and source records attributed to Soumaya El Rouby.

3 recordsLinked to original sources

PubMed2006

The use of a HEMOCHRON JR. HEMONOX point of care test in monitoring the anticoagulant effects of enoxaparin during interventional coronary procedures.

BACKGROUND: Enoxaparin is increasingly used for the anticoagulation of patients undergoing percutaneous coronary intervention (PCI). Several reports have suggested the utility of using point of care tests in monitoring the anticoagulation levels of enoxaparin in patients undergoing PCI. The objective of this study was to evaluate a new point-of-care test (POCT) HEMONOX in monitoring the anticoagulant effect of enoxaparin in non citrated fresh whole blood samples from patients undergoing elective PCI procedure. METHODS: Following IRB approval, blood samples were obtained from fifty-four patients who received two sequential intravenous doses of enoxaparin; 0.1 mg/kg followed 5 min later by 0.4 mg/kg for a total of 0.5 mg/kg. Blood was drawn at baseline and at 5, 10, 30 and 60 min post first bolus for evaluation in the clot-based POCT HEMONOX, ACT and aPTT and the chromogenic anti-Xa activity assay. RESULTS: HEMONOX clotting time (CT) at baseline was 62.6 +/- 6.2 secs, (n = 32) in healthy donors and statistically higher in PCI patients (71.6 +/- 9.1 secs, p = 0.0001). The peak HEMONOX response that was always achieved at 10 min post bolus was >100 secs in all 54 patients, of these 83% yielded CT >150 secs (range: 150-466). There was no detectable anti-Xa activity level at baseline while peak HEMONOX CT corresponded to therapeutic levels (0.85 +/- 0.14 U/ml; range: 0.61-1.34). Both HEMONOX CT and anti-Xa level significantly decreased at the time of sheath removal. HEMONOX CT at peak response suggested 3 patient subgroups with different levels of sensitivity to enoxaparin: low, intermediate and high responders. The correlation between anti-Xa activity level and HEMONOX CT was >or=0.85 in each patient subgroup when data from the 3 critical time points; baseline (absence of drug), peak response (10 min post bolus) and sheath removal (60 min post bolus) were analyzed. The correlation diminished to >or=0.83 when the analyses included data from all 5 time points [baseline, 5, 10, 30, and 60 min post bolus]. The HEMONOX test was the most sensitive POCT to measure the anticoagulant effects of enoxaparin. All patients completed PCI successfully. CONCLUSION: The HEMONOX test may be able to guide anticoagulation with enoxaparin during PCI. The HEMONOX assay is a one step whole blood coagulation test performed on the HEMOCHRON Jr. Signature + POC system. The method was evaluated to monitor the anticoagulant level of enoxaparin in blood samples from patients undergoing PCI after receiving an intravenous dose of 0.5 mg/kg. The results suggest a clear distinction of HEMONOX CT between the baseline value of untreated patients and patients achieving therapeutic enoxaparin levels.

Adult↗

PubMed2004

Racial and ethnic differences in warfarin response.

BACKGROUND AND AIM OF THE STUDY: Variability of drug response among individuals is a well-recognized problem that may result in either under- or overtreatment of patients receiving similar drug concentrations. Patients with mechanical heart valves are dependent on adequate anticoagulation to prevent thrombosis development. 'Crystalline warfarin sodium' (warfarin) is the most common antithrombotic drug prescribed to control blood hemostasis in those patients, and also in those with indications such as stroke, myocardial infarction, pulmonary embolism and atrial fibrillation. Warfarin is a narrow therapeutic index agent; a small change in systemic concentration of the drug may lead to significant changes in pharmacodynamic response. Careful clinical management is required to balance the risks of bleeding (over-anticoagulation) with those of thrombosis (under-anticoagulation). The study aim was to summarize environmental, genetic and ethnic factors that affect a patient's response to warfarin and which must be considered for optimal patient outcome. METHODS: A Medline search was carried out to summarize various factors that influence a patient's response to warfarin. RESULTS: Inter-ethnic differences may have profound implications for the efficacy and safety of warfarin. Ethnic differences can affect pharmacokinetic features such as bioavailability, protein binding and volume of distribution, as well as hepatic metabolism and renal elimination. Environmental factors and genetic variants in human enzymes that metabolize warfarin also contribute to interindividual variations and may render some patients more susceptible to serious or life-threatening adverse events. CONCLUSION: Warfarin use is complicated by an unpredictable dose response that depends on factors such as demographics, diet, interacting drugs, genetic polymorphism and ethnic differences. The impact of racial differences on the kinetics of dose response or on drug efficacy is not well defined, as few clinical trials take ethnic variation into account. The use of the point of care and frequent patient self-testing may permit standardized warfarin monitoring across diverse geographical regions and facilitate analysis of ethnic variation among subpopulations.

Anticoagulants↗

PubMed2003

Hand-held personal digital assistant program for the HEMOCHRON RxDx heparin and protamine dosing system.

The use of in vitro dosing assays for heparin and protamine during cardiac surgery has significantly improved overall postoperative patient outcome. The HEMOCHRON RxDx system (International Technidyne Corp, Edison, NJ) is widely used for anticoagulation management. Based on a series of consecutive in vitro tests, the RxDx system is used to quantify the patient's heparin requirement (heparin response test, HRT), measure the activated clotting time (ACT), calculate the blood heparin concentration and the required protamine dose (protamine response test, PRT), as well as determine the efficacy of heparin reversal (protamine dose assay, PDA-O). A hand-held personal digital assistant (PDA) program has been developed that performs the RxDx calculations used for anticoagulation management during cardiac surgery. The Palm m505 hand-held device (Palm, Inc., Santa Clara, CA) is used in concert with any standard Hemochron blood coagulation system. The Palm m505 device has been programmed to perform all the calculations required for the RxDx test system. Patient's body weight, height, and gender are entered into the program using the onscreen keypad and the template provided in the Hemochron program. The calculator automatically provides the patient's blood volume and the recommended heparin dose upon entering the baseline ACT and HRT values and a target ACT. At the end of the case, the optimal protamine dose is determined, and the total heparin level is calculated and displayed upon entry of ACT and PRT clotting times. Following protamine administration, the program calculates any additional protamine required to neutralize residual heparin using the data from a PDA-O test. The RxDx hand-held PDA is accurate, quick, simple, and easy to use, patient data are saved and can be retrieved. The inclusion of this rapid computing technology into the Hemochron RxDx system serves to expand the applications of the Hemochron RxDx system during cardiac interventions.

Alabama↗