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Biomedical subjects

C Saint-Marc

Publications and source records attributed to C Saint-Marc.

16 recordsLinked to original sources

[Effects of propofol on intraocular pressure in surgery of strabismus in children].

Propofol was assessed for eye surgery in 20 children. ASA group I or II, 2-14 year-old, randomly assigned to 2 equal groups. Premedication, analgesia and muscle paralysis were similar in both groups. Group P patients were given an induction dose of 4 mg.kg-1 propofol, followed by an infusion of 15 mg.kg-1.h-1 for the first half hour, and then 10 mg.kg-1.h-1 to maintain anaesthesia. Group C patients were given 10 mg.kg-1 thiopentone for induction and halothane for maintenance. The quality of anaesthesia was assessed by monitoring adverse effects, heart rate, blood pressure, the length of anaesthesia, the delay of the first spontaneous breath and eye opening, and extubation. Intraocular pressure was measured before and 3 min after intubation, and 5 min after extubation. The quality of anaesthetic induction and maintenance were very similar in both groups. Pain occurred more frequently at the injection site with propofol (p less than 0.01). Children in group P recovered more quickly, and extubation was possible much earlier in this group (p less than 0.05). However, restlessness was significantly more frequent in group P (n = 9) than in group C (n = 1) (p less than 0.01). Systolic, diastolic blood pressure and heart rate were significantly lower in group P (p less than 0.05; 0.001; 0.001 respectively). No significant decrease in intraocular pressure in both groups was observed. The use of propofol for eye surgery in children is acceptable, despite some restlessness during recovery.

Adolescent

[Liver transplantation in metastases of carcinoid tumor].

A 30-year-old woman underwent a liver transplantation for metastasis of a carcinoid tumor of the midgut previously resected. Operative manipulation of the liver resulted in arterial hypotension, tachycardia, high pulmonary arterial pressure, oedema of the face and peripheral cyanosis, although the patient was given somatostatin (Modustatine, Clin-Midy) (300 micrograms a hour) prior to the procedure. The improvement of the symptoms was obtained by the increase of somatostatin infusion rate to 750 micrograms a hour associated with dopamine (6 micrograms.kg-1.min-1) and fluid replacement. The diagnosis of carcinoid syndrome is discussed. This unusual observation stresses the difficulty in preventing and/or treating a carcinoid shock. If somatostatin seems to be the treatment of choice of such a syndrome, its role in that case was limited.

Adult

Effects of halothane on human and rat hepatocyte cultures.

The aim of this study was to investigate direct cytotoxicity to human and rat hepatocytes in primary culture from halothane and compare it with that of isoflurane, which is known to be minimally metabolized and less toxic in vivo. Both human and rat parenchymal cells were isolated by the two-step collagenase perfusion method and after attachment to plastic were incubated with either volatile anesthetic for 24 h. All the cultures were maintained in 20% O2 condition and were not induced prior to anesthetic treatment. Temperature, atmosphere conditions, and anesthetic concentrations were kept constant during the study period. Evaluation of cytotoxicity was based on morphologic, biologic (determination of both extracellular and intracellular lactate dehydrogenase activity), and metabolic (protein synthesis and secretion) end points. Protein synthesis and secretion rates were found to be the most sensitive parameters in hepatocyte cultures from both species. Protein synthesis was inhibited by 18% and protein secretion by 50% in the presence of 1 and 1.25 mM halothane, respectively, in human cell cultures (P less than 0.05). With 1.25 mM halothane intracellular lactate dehydrogenase was also decreased; lactate dehydrogenase leakage and morphologic alterations were detected only beyond 5 mM halothane. By contrast, in rat hepatocyte cultures protein secretion was inhibited by 26% and protein synthesis by 20% in the presence of 0.1 and 0.75 mM halothane, respectively, whereas morphologic alterations and a 37% lactate dehydrogenase leakage increase were observed with the concentration of 1 mM (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

[Digestive stress hemorrhage. Physiopathology and prevention].

Lesions of the gastroduodenal mucosa are seen very early on in virtually 100% of patients suffering from organ failure. Bleeding, even if it is only occult, defines acute stress-induced gastrointestinal tract bleeding (SGIB). The rates of SGIB vary according to the inclusion criteria: 13 to 100% microscopic SGIB, 2.3 to 9.5% haemorrhage with blood transfusion and/or shock. Gastrointestinal bleeding does not really influence the death rate of patients with SGIB (0 to 5% increase). Damage to the gastric mucosa may be due to an intraluminal aggression, and/or decreased mucosal and mural defence mechanisms. H+ ions and bile salts are mostly responsible for the former. Physiological quantities of H+ ions may be sufficient, as their abnormal diffusion into the gastric mucosa will reduce the mucosal pH (pHm), which is itself sensitive to microcirculatory modifications and systemic acidosis. There is a good correlation between bleeding and pHm. Bile salts are involved because of the usual increase in frequency and volume of gastric biliary reflux due to stress. Surfactant, mucosal alkaline layer and the microcirculation are all involved in gastric protection. The PGE2 synthetized by the gastric mucosa have a favourable influence on these 3 mechanisms. Changes in microcirculation and hypoxia are the predominant factors involved in stress-induced mucosal damage. The prevention of SGIB relies on the treatment of risk factors, a reduction of intraluminal aggression, and the support and/or stimulation of gastric defence mechanisms. Antacids and anti-H2 drugs aim to neutralize most of the H+ ions, being more efficient than placebo in increasing gastric pH greater than 4, although anti-H2 agents are responsible of a greater number of failures. The non-homogenous character of the patient groups studied and the diagnostic methods, as well as the increasing lack of placebo groups in the published studies make the interpretation of the results rather risky. Antacids and anti-H2 drugs are more efficient than placebo, and equally efficient, in preventing overt SGIB. Efficiency is increased by giving anti-H2 drugs continuously, and antacids hourly. Other agents are thought to protect mucosal cells, probably increasing mucosal defences. Amongst them are the prostaglandins, the most interesting of which are still being investigated, and sucralfate. The latter molecule is as efficient as antacids and anti-H2 drugs, and does not alter gastric pH, so reducing the number of nosocomial pneumonias. Its reduced cost and easy administration make it, at the present time, the treatment of choice of SGIB. The few rare contraindications of sucralfate will justify the infusion of anti-H2 drugs in those patients at risk.

Anti-Ulcer Agents

[2 cases of the HELLP (Hemolysis Elevated Liver Low Platelet) syndrome].

Recently described by Weinstein, the "HELLP syndrome" is an entity of the pre-toxemic syndrome; its precise physiopathological mechanism, related to a thrombotic micro-angiopathy, is still not clearly established. Therefore, the treatment remains symptomatic, associated with the treatment of the toxemia. Two cases occurring in twin pregnancies are reported.

Adult

[Spontaneous rupture of an adenoma of the liver during pregnancy].

Must often reporting to an hepatic subcapsular hemorrhage with pre or true eclampsia, Spontaneous rupture of adenoma of the liver during pregnancy is unusual entity. Very exceptionally cases of rupture of anatomic hepatic lesion underlying had been reported. About a new case, diagnosis, physiopathologic and management problems are approached.

Adenoma

[Post-traumatic pneumatocele and hemato-pneumatocele of the lung. Apropos of 3 cases].

Pneumatocele and haemato-pneumatocele are air or air/fluid cavitary lesions which develop in the lung parenchyma after thoracic trauma. The formation of this lesion requires a direct violent impact on the pliable lung wall which explains its frequency in young adults. They are preferentially localised in the lung bases. The importance of associated lesions often marks the pneumatocele. Though rarely described, its frequency is certainly underestimated. If haemoptysis is the most frequent clinical sign it is the chest x-ray which demonstrates the early abnormality in the form of a rounded translucent image with a fine contour and variable diameter. The existence of a fluid level suggests the presence of blood (haemato-pneumatocele). The differential diagnosis with a localised pneumothorax, a diaphragmatic hernia and a pre-existing cystic lesion is easy as a rule but an evacuated pulmonary haematoma may lead to the discussion, especially as the mechanism of their formation may be the same. In isolation their clinical implications are minimal, their evolution favourable and after several weeks with a restitution of the integrity of the pulmonary parenchyma the absence of therapeutic intervention is justified.

Adolescent

[Prolonged intravenous infusion of morphine. Pharmacokinetic study].

Critically ill patients require optimal pain control without undesirable side-effects. Continuous intravenous morphine infusion is often chosen instead of the conventional intermittent administration. In the present study, the pharmacokinetic characteristics of morphine were studied in five subjects receiving a constant rate intravenous infusion with the attainment of a steady state. The plasma levels were compared with values derived from bolus intravenous administration in five other patients. The concentrations of unchanged morphine were determined in serum using high performance liquid chromatography with an electrochemical detector. The decay of plasma concentrations after a single dose fitted a triexponential function consistent with a three compartment pharmacokinetic model. Postinfusion plasma concentrations fitted a two compartment model. Derived values (mean +/- SEM) of total body clearance were significantly different between groups (p less than 0.05), while mean values of terminal elimination half-life (t 1/2 Kel) were similar. It was concluded that values of total distribution volume were significantly different. The extent of morphine distribution varied more than twofold between the two groups of patients. This was interpreted as a consequence of an important underestimation in the extent of distribution tissues after administration of a single dose.

Adult

[Spontaneous rupture of the esophagus].

Eighteen patients (16 men and two women), aged 20 to 77 years, were admitted to the University hospital between 1973 and 1984 for a Boerhaave's syndrome. Fourteen over eighteen were more than forty years old. Other particular features were the frequency of alcoholism (11 patients) and the lack of preexisting gastrointestinal symptomatology. The cardinal symptom, pain, occurred in 17 cases. It was preceded in 10 subjects by vomiting. Subcutaneous emphysema was only found in five patients, but standard chest X-ray showed seven times a pneumomediastinum. Pleural effusion was present in 14 subjects. Thirteen patients underwent thoracotomy: five within 48 h (1 death) and eight after 48 h (4 deaths); two further deaths were due to withholding surgery, and a third by performing bipolar oesophageal exclusion at a late stage (8th day); six of these deaths were related to local infection. The clinical and radiological features of Boerhaave's syndrome are presented in a review of the literature; particular attention is paid to the various methods of treatment.

Adult

[Epidural anesthesia during labor: comparison of 3 combinations of fentanyl-bupivacaine and bupivacaine alone].

The association of bupivacaine and fentanyl appeared as the best method of inducing satisfactory obstetrical analgesia. But the various techniques of drug administration had to be detailed; this justified the present work, a single-blind controlled trial performed on 159 primipara women at term (except one of them), randomized in four groups, after informed consent. In each group, the number of patients, the age and the degree of uterine dilatation at the beginning of the epidural anaesthesia were comparable. Epidural anaesthesia aimed to improve the maternal comfort during labour. After a first epidural injection of 10 ml, several other injections of 6 ml were carried out according to four different protocols (I, II, III, IV), with different concentrations of fentanyl (respectively 0, 0.05, 0.1 and 0.15 mg). The mean total dosages of fentanyl were statistically higher in the protocols III and IV. The foetal cardiac rhythm and uterine contractions were monitored continuously as well as maternal blood pressure and heart beats during labour. The following parameters were assessed: contraction pain intensity (five point scale), the onset of analgesia, the duration of analgesia, the length of labour, the interval between the first drug injection and subsequent injections, the type of delivery. In the newborn, Apgar score was assessed at 1, 5 and 10 min after delivery. The degree of analgesia was statistically improved in the groups receiving fentanyl, without any differences between them. On the other hand, the length of labour was shorter with protocol II (lowest concentration of fentanyl).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult