PubMed Health⌕ Search

Biomedical subjects

T Lechevalier

Publications and source records attributed to T Lechevalier.

6 recordsLinked to original sources
PubMed1996

Pharmacodynamic dose-response and safety study of cisatracurium (51W89) in adult surgical patients during N2O-O2-opioid anesthesia.

After administration of doses ranging from 0.025 to 0.25 mg/kg, the neuromuscular blocking effect of cisatracurium was assessed in 119 adult surgical patients receiving N2O-opioid-midazolam-thiopental anesthesia. The calculated 95% effective dose (ED95) for inhibition of adductor pollicis twitch evoked at 0.1 Hz was 0.053 mg/kg. With 0.10 mg/kg injected over 5-10 and 20-30 s, median onset times (range) were 5.8 (3.0-7.7) and 4.8 (1.2-10.2) min, respectively, and median times to 5% and 95% recovery (range) were 27 (19-46) and 48 (25-68) min, respectively. For doses of 0.10, 0.20, and 0.25 mg/kg, median 5%-95% and 25%-75% recovery indexes ranged from 48 to 90 min and 8 to 9 min, respectively. After administration of neostigmine (0.06 mg/kg) at 10%-15% or 16%-30% recovery, the median times to 95% recovery (range) were 6 (2-22) and 4 (2-5) min, respectively. There were no changes in heart rate, blood pressure, or plasma histamine concentrations during the first 5 min after administration of cisatracurium at doses up to 5 x ED95 injected over 5-10 s. No cutaneous flushing or bronchospasm was noted. In summary, cisatracurium is a potent neuromuscular blocking drug with an intermediate duration of action, characterized by excellent cardiovascular stability, with no apparent histamine release.

Adolescent↗
PubMed1996

Cardiac and regional hemodynamic interactions between halothane and nitric oxide synthase activity in dogs.

BACKGROUND: In vitro, halothane appears to affect the role played by nitric oxide in the regulation of vascular tone and cardiac function. In vivo, the results of the interactions between halothane and the nitric oxide pathway remain controversial. The authors investigated the effects of halothane on the cardiac and regional hemodynamic properties of N-methyl-L-arginine (NMA), a specific nitric oxide synthase inhibitor, in dogs. METHODS: Twenty-five dogs were chronically instrumented. Aortic pressure, the first derivative of left ventricular pressure, cardiac output, heart rate, and carotid, coronary, mesenteric, hepatic, portal and renal blood flows were continuously recorded. N-methyl-L-arginine was infused intravenously at 20 mg/kg over 1 min in awake dogs (n = 11) and in 1.2% halothane-anesthetized dogs (n = 10). As a control group, the remaining four dogs were studied awake and during 1.2% halothane for 2 h in the absence of NMA. RESULTS: In awake dogs, NMA produced a sustained pressor response (34%) and systemic vasoconstriction (40%) associated with a decrease in cardiac output (16%). Regional circulation changes included an immediate and transient increase in carotid (43%) and coronary (237%) blood flows and a subsequent decrease in carotid blood flow (25%). Hepatic and mesenteric blood flows also decreased, by 43% and 16%, respectively. Except for the coronary circulation, regional vascular resistance increased significantly. Halothane did not affect the pressor response to NMA but did blunt the cardiac output changes. Consequently, the systemic vasoconstriction after nitric oxide synthase inhibition was of shorter duration and of lesser magnitude during halothane anesthesia. Halothane also blunted the carotid, mesenteric, and renal vasoconstriction induced by NMA. Finally, in 1.2% halothane-anesthetized dogs, NMA induced a coronary vasoconstriction. CONCLUSIONS: Halothane minimally interferes with the systemic and regional hemodynamic consequences of nitric oxide synthase blockade. The nature and magnitude of the interaction depend on the territory in which they occur.

Anesthetics, Inhalation↗
PubMed1994

Rocuronium (Org 9426) for caesarean section.

This was a prospective, non-randomized, multicentre study of rocuronium (Org 9426) in 40 elective Caesarean section patients at full term without fetal distress. Anaesthesia was induced with thiopentone 4-6 mg kg-1 i.v. and rocuronium 0.6 mg kg-1 and maintained with isoflurane and nitrous oxide in oxygen. Monitors included ECG, arterial pressure, pulse oximeter and train-of-four (TOF) produced by ulnar nerve stimulation. In all patients, full neuromuscular block at the hand indicating the maximum effect of rocuronium (T1 = 0) occurred at a mean time of 98.1 (SE 9.4) s. However, after 79.3 (2.9) s, excellent to good intubating conditions were achieved in 90% of patients. Injection to delivery time was 12.7 (0.9) min and the surgical procedure lasted 53.1 (3.5) min. After administration of rocuronium, T2 appeared after 32.7 (1.8) min (indicating duration of effect). At the end of the surgical procedure in 39 patients, glycopyrronium 0.2 mg and neostigmine 1 mg were given every 5 min to antagonize residual neuromuscular effect. The mean dose of neostigmine required was 1.54 (0.1) mg. Rocuronium had no clinically significant effect on maternal heart rate or arterial pressure. After administration of thiopentone and rocuronium in two patients, temporary erythema occurred, one along the site of injection and the other on the chest wall. Rocuronium had no untoward effects on the neonates, evaluated by 1- and 5-min Apgar scores, time to sustained respiration, total and muscular neuroadaptive capacity scores, acid-base status and blood-gas tensions in umbilical arterial and venous blood.(ABSTRACT TRUNCATED AT 250 WORDS)

Androstanols↗
PubMed1994

Cardiovascular effects of NG-methyl-L-arginine in chronically instrumented conscious dogs.

The cardiovascular effects of nitric oxide blockade were examined in five conscious chronically instrumented dogs. The hypothesis tested was that nitric oxide release plays a role in vascular tone and regional organ blood flow under physiological conditions. Aortic pressures; the first derivative of the left ventricular pressure; cardiac output (CO); heart rate; and carotid, coronary, renal, hepatic, and portal blood flows were recorded before and after bolus injection of 5, 10, and 20 mg/kg of NG-methyl-L-arginine (L-NMA). In response to L-NMA, mean arterial pressure increased by 7, 20, and 35%, respectively, in a dose-dependent manner, whereas CO decreased. CO reduction was sustained at the highest dose, whereas peripheral blood flows were not altered. These data suggest that blocking basal nitric oxide synthesis by administering L-NMA leads to a modest dose-dependent pressor response despite a marked and sustained reduction in CO recorded at the highest dose of L-NMA. Moreover, within our dose range, although the nitric oxide synthase inhibition provides a significant pressor response, it does not alter the resting carotid, coronary, renal, hepatic, and portal blood flows.

Amino Acid Oxidoreductases↗
PubMed1982

[Management of pulmonary metastases from osteosarcomas].

The management of pulmonary metastases from osteosarcomas rests at present on thoracic surgery combined with chemotherapy. Until the beginning of the seventies chemotherapy proved very disappointing. With adriamycin, methotrexate in high doses followed by folinic acid and, more recently, platinum cis-dichlorodiamine, remissions, which are usually partial, are obtained in a significant proportion of patients (at least 30%). The addition of less active agents such as vincristine, cyclophosphamide, actinomycin D and bleomycin is helpful. Among 31 patients with pulmonary metastases from treated osteosarcomas seen at the Gustave Roussy Institute, 18 underwent thoracic surgery as the first treatment; in 10, surgery was followed by chemotherapy with adriamycin, vincristine, methotrexate in high doses + folinic acid + cyclophosphamide. Five patients are in complete remission 27, 30, 49, 50 and 77 months after the surgical procedure. 12 patients were initially treated with a similar chemotherapeutic regimen; a subsequent thoracic surgical procedure was undertaken in two patients who died 18 and 30 months after the pulmonary metastases had appeared. In one patient, the metastases were treated by irradiation. These results are compared to previous reports in the medical literature.

Humans↗