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Biomedical subjects

M Chauvin

Publications and source records attributed to M Chauvin.

At least 19 recordsLinked to original sources
PubMed2007

Role of pre-infarction angina and inflammatory status in the extent of microvascular obstruction detected by MRI in myocardial infarction patients treated by PCI.

BACKGROUND/OBJECTIVES: The extent of microvascular obstruction (MVO) during myocardial infarction referred to as the "no-reflow phenomenon", may determine myocardial damage. Our study aimed to investigate the incidence and the influencing factors of MVO in patients with ST-elevation myocardial infarction (STEMI) treated by primary percutaneous intervention (PCI). PATIENTS, METHODS: Using contrast-enhanced MRI, microvascular obstruction was defined as early hypoenhancement. Contrast defects were scored from 0 (no hypoenhancement) to 3 (strong hypoenhancement). 50 patients (56+/-11 years) with STEMI underwent PCI. Contrast-enhanced MRI (6+/-2 days after STEMI) and biochemical parameters were evaluated. RESULTS: Microvascular obstruction (score 1 to 3) was observed in 90% of the patients and major microvascular obstruction (score 2-3) in 54%. In univariate analysis, leukocytes and CRP levels were associated with MVO, whereas pre-infarction angina and prior medication by aspirin or calcium channel antagonist appeared protective. Microvascular obstruction intensity positively correlated with baseline inflammation status assessed by C-reactive protein and leukocytes (rho=0.43 and rho=0.44; p=0.003), the peak of CK (rho=0.56; p=0.01) or Troponin I (rho=0.59; p=0.01) and negatively correlated with LVEF (rho=-0.44; p=0.002). Multivariate analysis identified the absence of pre-infarction angina as the only independent predictor for microvascular obstruction (odds ratio, 8.35, 95% confidence interval 1.27-54.71; p=0.027). CONCLUSION: MRI-detected microvascular obstruction has a high incidence in patients with STEMI treated by primary PCI and determines post-MI LVEF even in patients with post PCI TIMI 3 flow score. Pre-infarction angina appears to be an independent determinant of the extent of MVO detected by MRI.

Adult↗
PubMed2006

Superconducting atomic contacts under microwave irradiation.

We have measured the effect of microwave irradiation on the dc current-voltage characteristics of superconducting atomic contacts. The interaction of the external field with the ac supercurrents leads to replicas of the supercurrent peak, the well-known Shapiro resonances. The observation of supplementary fractional resonances for contacts containing highly transmitting conduction channels reveals their nonsinusoidal current-phase relation. The resonances sit on a background current which is itself deeply modified, as a result of photon-assisted multiple Andreev reflections. The results provide firm support for the full quantum theory of transport between two superconductors based on the concept of Andreev bound states.

Journal Article↗
PubMed2006

Evaluation of the pharmacokinetic profile and analgesic efficacy of oral morphine after total hip arthroplasty.

BACKGROUND AND OBJECTIVE: Oral morphine may be useful for postoperative pain relief, but few studies have tested its use after in-hospital surgery. METHODS: We evaluated clinical efficacy and the pharmacokinetic parameters of oral morphine after total hip arthroplasty. We recruited 60 patients who had total hip arthroplasty under general anaesthesia. The patients were randomized to receive placebo, 10 mg morphine sulphate or 20 mg morphine sulphate orally every 4 h for 24 h. The oral administration was started 3 h after the morphine-loading dose in the Post Anaesthesia Care Unit and then patients used intravenous morphine patient-controlled analgesia for 24 h. Pain score at rest (scored by patients on a visual analogue scale), sedation, nausea, vomiting and urinary retention were monitored. In 11 additional total hip arthroplasty patients, we determined the pharmacokinetics of morphine and its metabolites after oral administration of 20 mg morphine sulphate every 4 h for 16 h. RESULTS: The amount of morphine administered via patient-controlled analgesia over 24 h was reduced in the 20-mg group compared with that in the placebo group (19.0 +/- 2.7 mg vs. 33.0 +/- 5.5 mg; P = 0.03). No significant morphine-sparing effect was observed in the 10-mg group. Pain scores and side-effects were similar in all groups. The pharmacokinetic study revealed a limited and slow absorption of morphine. CONCLUSION: Despite a limited absorption of oral morphine postoperatively, high doses of oral morphine have a significant analgesic effect after total hip arthroplasty.

Administration, Oral↗
PubMed2006

[Evaluation of duration for direct admission dispatch process in an urban area].

OBJECTIVE: In France, when physicians in ambulances take care of patients, they report medical status to the dispatch centre. Then the dispatching physician search for the available and appropriate hospital service to agree in directly receiving the patient. We attempted to evaluate this direct admission dispatch, in a urban area, with many health care facilities. STUDY DESIGN: Prospective evaluation. PATIENTS AND METHODS: All the files for out of hospital interventions with a dispatch process were included. Data collected and analysed were: main pathologies, started time and end time of direct admission dispatch process and number of services called before finding the right place. RESULTS: 959 patients files were included, 849 could be analysed. The average duration of direct admission dispatch process is 10 (+/-13) minutes. Traumatology speciality shows a longer dispatch process than medicine disease (p < 0.001), and this time increased during summer (p < 0.05). The other parameters did not influence this duration. CONCLUSION: The average duration of direct admission dispatch process is acceptable. The increased duration of direct admission dispatch process in some pathology during summer may induce a risk for the patients. This problem will be improved only when the management of the available bed for emergency traumatology, will be implemented a regional coordination.

Adult↗
PubMed2006

[The best of cardiac pacing in 2005].

In 2005, the main subject of interest in the field of pacing was cardiac resynchronisation. The results of CARE-HF (Cardiac Resynchronisation on Morbidity and Mortality in Heart Failure), a large multicentre trial, were published. The investigators set out to establish whether resynchronisation pacing had a favourable effect on morbidity and mortality in patients with advanced cardiac failure and desynchronised compared with an identical population treated medically. The results showed that resynchronisation decreased the interventricular desynchronisation, decreased mitral regurgitation and, above all, improved symptoms and quality of life with a reduction in the incidence of complications and the risk of death. This publication is too recent for evaluation of the eventual repercussions of these results on the implantation of resynchronising pacemakers in France. The indication recommended by the scientific societies is still based on criteria which do not take echocardiographic data into account. However, the recommendations will probably change in the near future when the conclusions of trials currently under way, are published. From the technical point of view, the advances in cardiac pacing were mainly the new algorithms which avoid inappropriate ventricular stimulation of dual chamber pacemakers. It is well known that patients implanted with dual chamber pacemakers may, despite optimal adjustment of pacing parameters, have ineffective ventricular stimulation as the impulse falls in the phase of spontaneous ventricular depolarisation or effective but absolutely valueless. Several manufactures now propose pacemakers with algorithms which "search" for ventriculogrammes in order to avoid these situations of inadequate stimulation. Their efficacy has been demonstrated. Finally, in 2005, the diffusion of defibrillators equipped with a resynchronisation function has been confirmed. The conclusions of the COMPANION trial have been influential in promoting this usage although the results are mainly observed abroad.

Cardiac Pacing, Artificial↗
PubMed2006

[Implantable cardioverter defibrillators in pediatric patients: results in a series of 33 cases].

UNLABELLED: Implantable defibrillator is the recognized treatment of sudden cardiac death. Miniaturization of the devices allows implantation in children. METHODS: This multicentric retrospective study analyzed data of 33 children aged 18 years and less who were implanted from 1990 to 2005. RESULTS: Age of patients are 10 to 18 years, 20 patients were implanted after a resuscitation of sudden death, 10 after a syncope, 2 after a ventricular tachycardia and 1 in a prophylactic way. Tachycardias on primary electrical disease are most frequent (46%). Hypertrophic cardiomyopathy accounts for 22%, DAVD for 14%, congenital cardiopathies for 12%. Seventeen patients received appropriate shocks and 14 patients had inappropriate shocks. There were two unexplained deaths. Five leads fractures and two device infections were noted. CONCLUSION: Implantable defibrillator is an effective treatment for children high-risk of sudden death. Occurrence of inappropriate shocks due to sinusal tachycardia, infections and leads fractures are frequent.

Adolescent↗
PubMed2005

[Reversible cardiogenic shock under 5-fluorouracil treatment].

5-fluorouracil, an antimetabolite agent, has been widely used since 1957 for treatment of varied types of cancer such as gastro-intestinal, pancreas, breast, lung, head and neck malignancies. Cardiotoxicity of 5-fluorouracil is rare and was first described in 1975. It can induce severe complications and involve vital prognosis in the short-term. These complications are less known by cardiologists than medical oncologists. The following clinical case represents a potentially serious and rare case of completely reversible cardiogenic shock in a patient with a colo-rectal cancer. A better knowledge of these complications could reduce cases of death by an earlier diagnosis, and a better evaluation of patients with high cardiotoxicity risk.

Adenocarcinoma↗
PubMed2005

[Uncommon aetiology of peroneal compartment syndrome].

Compartment syndromes are well recognized following major trauma. However, although uncommon, they may occur following athletic activity. We report a case of acute exertional peroneal compartmental syndrome in a 32-year-old that developed following horse riding. Because of the ignorance of pathology, a regional analgesia was carried out resulting in delayed diagnosis. Postoperative electromyography showed the absence of a fibula nerve compound action potential. At one-year follow-up visit following decompressive fasciotomy, muscular strength of the muscles of the anterior tibial compartment almost returned to normal. The presentation of this case of compartmental syndrome following horse riding allows to discuss the place of the regional anaesthesia. Because this anaesthesia technique can delay the diagnosis and the surgical treatment, it should not be used in first intention in the treatment of severe pain associated with compartmental syndrome.

Adult↗
PubMed2005

[The best of cardiac pacing in 2004].

The year 2004 saw the publication of the results of the COMPANION and PAVE studies concerning cardiac pacing. The former underlined, if it was still necessary, the direct relationship between pacing and rhythmology in terms of sudden death due to rhythm disturbances in cardiac failure. COMPANION attempted to discover whether, in severe cardiac failure with intraventricular conduction defects, the addition of multisite pacing either with or without defibrillation is liable to alter the combined risk of death and hospital episodes compared with optimal drug therapy alone. This study confirmed the advantages of resynchronisation pacing already observed in MUSTIC, MIRACLE, InSync and CONTAK CD: retarded progression of cardiac failure, reduction in the number of hospitalisations and functional improvement. Adding defibrillation to anti-bradycardial resynchronisation pacing improved the survival, but only slightly so. On the other hand, the size of the subgroups did not allow any conclusions to be drawn about function and aetiology of cardiac failure, whether ischaemic or not. The PAVE study allowed comparison between biventricular pacing and right ventricular pacing alone in patients in NYHA class II or III, with atrial fibrillation for more than one month and having undergone elective ablation of the nodo-Hissian pathway. The results gave confirmation of the harmful effects of pacing at the apex of the right ventricle in pacing-dependent patients. On the technological front, there was confirmation that probes designed for left ventricular stimulation are stable and increasingly easy to use thanks to a new configuration and the use of bipolar. Finally, telecardiology has started to proliferate and evaluation of its applications is under way, even though its clinical use is confirmed on a daily basis.

Arrhythmias, Cardiac↗
PubMed2004

Systemic lidocaine in pain due to peripheral nerve injury and predictors of response.

OBJECTIVE: To investigate the effects of IV lidocaine on spontaneous and evoked pain (allodynia and hyperalgesia) due to peripheral nerve injury (postherpetic neuralgia or nerve trauma) using quantitative sensory testing. METHOD: The authors randomized 22 patients to receive lidocaine 5 mg/kg IV during 30 minutes or placebo in a double-blind crossover design and 16 patients subsequently received mexiletine on an open basis titrated from 400 to 1,000 mg per day (mean 737 mg/day). RESULTS: Lidocaine induced a significant decrease in ongoing pain for up to 6 hours with a peak effect 60 to 120 minutes postinjection. The drug also decreased mechanical dynamic allodynia and static (punctate) mechanical allodynia/hyperalgesia, but not thermal allodynia and hyperalgesia. The effects of lidocaine and mexiletine on spontaneous pain intensity were significantly higher in patients with concomitant mechanical allodynia in comparison with those without allodynia. CONCLUSIONS: These data indicate modality-specific antihyperalgesic effects of IV lidocaine in patients with peripheral nerve injury. Patients with mechanical allodynia may be good candidates for treatment with local anesthetic-like drugs and possibly with other sodium-channel blockers.

Adult↗
PubMed2004

Desflurane-remifentanil-nitrous oxide anaesthesia for abdominal surgery: optimal concentrations and recovery features.

BACKGROUND: Intraoperative combinations of volatile and opioid agents are used to achieve unconsciousness, hypnotic sparing, haemodynamic stability and uneventful recovery. This study describes the influence of different remifentanil concentrations on these variables when combined with desflurane during abdominal surgery. METHODS: Sixty-one healthy adult patients were randomly allocated to one of five predefined remifentanil target concentrations (3, 5, 7, 10 or 15 ng ml(-1)). Anaesthesia was titrated to maintain mean blood pressure (MBP), heart rate (HR) and BIS trade mark within predetermined values by adjusting desflurane delivery. Postoperative analgesia using propacetamol and morphine was initiated 30-45 min before skin closure, and continued using morphine PCA. RESULTS: Desflurane requirements adjusted to both BIS and haemodynamics were not significantly modified by the remifentanil concentration (median Fet(DES) 2.7% before incision, 2.5% intraoperatively, and 2.2% during closure), resulting in a calculated drug consumption of 0.22-0.25 ml min(-1) (with 1.5 l min(-1) fresh gas flow). High remifentanil concentration decreased MBP and HR, and reduced the duration of tachycardia, but increased the duration of hypotension. The optimal balance was obtained with a remifentanil concentration of 5-7 ng ml(-1) for intubation, 3 ng ml(-1) until incision, 10 ng ml(-1) during intra-abdominal surgery and 5-7 ng ml(-1) during closure. Post-operative morphine requirements were not significantly modified by intraoperative remifentanil concentrations (median 30 mg/24 h, range [2-88]). CONCLUSION: Remifentanil target concentrations from 3 to 15 ng ml(-1) had little influence on desflurane requirements or postoperative morphine consumption, but markedly modified intraoperative haemodynamic stability, suggesting that the target concentration should closely follow the successive noxious stimulations.

Abdomen↗
PubMed2004

Circulating procoagulant microparticles and soluble GPV in myocardial infarction treated by primary percutaneous transluminal coronary angioplasty. A possible role for GPIIb-IIIa antagonists.

Circulating procoagulant microparticles (MP) were measured as markers of vascular damage and prothrombotic risk in patients undergoing ST-segment myocardial infarction (STEMI) treated by primary percutaneous transluminal coronary angioplasty (PTCA) and additional GPIIb-IIIa antagonists. Cells possibly more responsive to GPIIb-IIIa (alpha(IIb)beta(3)) antagonists were evidenced through MP phenotypes by comparison with healthy volunteers (HV) and STEMI patients treated by PTCA without GPIIb-IIIa antagonist (CP). In 50 STEMI patients, blood samples were collected at day 1 and day 6. Circulating procoagulant MP were captured on annexin V and quantified by prothrombinase assay as nanomolar phosphatidylserine equivalents (nm PhtdSer). Platelet activation by thrombin was confirmed through independent measurement of soluble GPV (sGPV). With respect to HV, procoagulant MP levels were high in patients with STEMI or unstable angina, platelet-derived MP and elevated sGPV testifying to significant platelet activation. A substantial release of endothelial-derived MP was evidenced simultaneously. In abciximab-treated patients, procoagulant MP, mainly of platelet origin, decreased precociously at day 1 (4.2 +/- 0.6 vs. CP 15.5 +/- 2.1 nm PhtdSer; P = 0.001) together with sGPV (36 +/- 3 vs. CP 58 +/- 8 ng mL(-1); P = 0.02). Leukocyte-derived MP decreased at day 6 (0.12 +/- 0.04 vs. CP 0.56 +/- 0.12 nm PhtdSer; P = 0.01) suggesting a possible effect on underlying inflammatory status. In patients presenting cardiovascular events at 6-month follow-up, procoagulant MP levels at day 1 could be indicative of a worsened outcome. MP could constitute a relevant parameter for the follow-up of STEMI patients treated by GPIIb-IIIa antagonists.

Abciximab↗