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J P Estebe

Publications and source records attributed to J P Estebe.

At least 19 recordsLinked to original sources
PubMed2005

[Thromboprohylaxis in orthopedic surgery and traumatology].

Orthopaedic and trauma surgery are classified according 3 groups of venous thromboembolic risk. Elective total hip replacement (THR) or total knee replacement (TKR), hip fracture surgery or trauma patients are at high risk. Isolated lower extremity injury with fracture is at moderate risk whereas this risk is low without fracture as well as with knee arthroscopy. In THR and TKR, low molecular weight heparin (LMWH), fondaparinux or melagatran-ximelagatran are strongly recommended. The routine use of other anticoagulants, in particular vitamin K antagonist are not recommended. In patients at high risk of venous thromboembolism as for example trauma patients, optimal use of intermittent pneumatic compression is an alternative option in case of contra-indication to anticoagulant prophylaxis. Graduated compression stockings enhance the efficacy of pharmacological methods. In schedule surgery, initiation of prophylaxis with LMWH may be started postoperatively. To reduce the haemorrhagic risk of anticoagulants, timing of first postoperative dose is essential and is proper to each drug. Duration of prophylaxis depends on the surgical and the individual patients' risk. Extended prophylaxis in THR for up to 42 days with LMWH and up to 35 days with fondaparinux in hip fracture surgery is recommended. However extended prophylaxis after 14 days in TKR has not demonstrated a higher efficacy and should only be considered for patients with additional risk factors. In patients with isolated lower extremity injury or undergoing knee arthroscopy, LMWH should not be routinely used according to a low or a moderate risk and/or the duration of prophylaxis required. But LMWH has to be considered for patients with additional risk factors. Prophylaxis in other orthopedic procedures has not been assessed and will be extrapolated from the above recommendations.

Animals↗
PubMed2003

Effect of dexamethasone on motor brachial plexus block with bupivacaine and with bupivacaine-loaded microspheres in a sheep model.

BACKGROUND AND OBJECTIVE: It has been suggested that dexamethasone potentiates the sensory block produced by bupivacaine when both drugs are loaded in microspheres. The aim of the study was to evaluate the effect of dexamethasone on the brachial plexus block obtained with plain bupivacaine and bupivacaine-loaded microspheres. METHODS: Dexamethasone alone (Group 5) or added to plain bupivacaine (75 mg) with (Groups 3 and 4) and without pH correction (Group 2) was compared with plain bupivacaine (75 mg; Group 1). The effect of a small dose of dexamethasone (0.42 mg) was then evaluated on the brachial plexus block obtained with bupivacaine (750 mg) as bupivacaine-loaded microspheres (Group 6). Dexamethasone was added either in the suspending medium (Group 7) or incorporated with bupivacaine into microspheres (Group 8). The motor block was evaluated in a plexus brachial sheep model. RESULTS: Dexamethasone alone did not produce any motor block. When added to plain bupivacaine without pH correction, complete motor block could not be obtained. When the pH was corrected, addition of dexamethasone to plain bupivacaine seemed to delay the onset of motor block and did not prolong its duration, and it had no effect on the pharmacokinetics of bupivacaine. With bupivacaine-loaded microspheres, the duration of complete motor block was reduced when a small dose of dexamethasone was added in the suspending medium. However, the duration of motor block was significantly prolonged when dexamethasone was incorporated with bupivacaine into microspheres. CONCLUSIONS: Despite the delayed onset of motor block, the incorporation of dexamethasone in bupivacaine-loaded microspheres dramatically increases the duration of action (700 +/- 485-5160 +/- 2136 min), which could be clinically relevant when such a drug-delivery system will be available.

Anesthetics, Local↗
PubMed2002

Pilot study on the effect of tourniquet use on sufentanil pharmacokinetics.

STUDY OBJECTIVE: To test our hypothesis that sequestration of sufentanil can occur during surgery when a pneumatic tourniquet is used. DESIGN: Prospective, randomized study. SETTING: Operating room and recovery room of a university hospital. PATIENTS: 16 ASA physical status I and II patients scheduled for orthopedic surgery with pneumatic tourniquet use. INTERVENTION: Patients were randomized to three groups. Sufentanil was given intravenously at 0.5 microg kg(-1) bolus at the same time that a constant infusion was started at 0.5 microg kg h(-1). In Group 1, continuous infusion of sufentanil was stopped when the tourniquet was released (n = 6). In Group 2, continuous infusion of sufentanil was stopped 15 minutes after tourniquet release (n = 6). In Group 3, as a control group, the sufentanil bolus was started after tourniquet inflation (n = 4). MEASUREMENTS: Plasma sufentanil concentrations were determined by radioimmunoassay. To compare pharmacokinetic results, a simulation of the sufentanil plasma concentrations was achieved. MAIN RESULTS: Exsanguination and inflation of the pneumatic tourniquet had no significant effect on pharmacokinetic results. In 75% of patients, a significant increase in sufentanil plasma concentration occurred between 30 and 60 minutes after tourniquet deflation in all three groups, probably as a result of patient mobilization. One respiratory distress event occurred in a Group 2 patient following extubation at 55 minutes after the end of the sufentanil infusion. The rebound of sufentanil concentration was higher in Group 2; it may be due to a reduced effect of the restoring circulation in the ischemic leg by a prolonged infusion after tourniquet deflation. CONCLUSIONS: Using a pneumatic tourniquet induces transient changes in the pharmacokinetics of sufentanil. These changes may have clinical relevance during the first hour after tourniquet release.

Adult↗
PubMed2001

Endotracheal tube cuffs filled with lidocaine as a drug delivery system: in vitro and in vivo investigations.

The purpose of this study was to examine if lidocaine diffusion across an endotracheal tube cuff could improve post-operative tolerance, especially sore throat. The in vitro release of lidocaine from tube cuffs filled with different lidocaine formulations (base form, hydrochloride form or alkalinized lidocaine hydrochloride) was investigated. A preliminary pilot clinical study in anaesthesia for spine surgery in smoker patients was carried out to examine the pharmacokinetic (i.e. systemic uptake) and pharmacodynamic effects (i.e. incidence of sore throat) obtained with the endotracheal tube cuff filled with lidocaine solution, compared to cuffs inflated only with air. From our in vitro experiment, only the hydrophobic neutral base form of lidocaine was able to diffuse (65.1+/-1.1% released after 6 h), while for the charged hydrochloride form, only a permeation phenomenon occurred concerning only 1% of the total drug. Alkalinization of lidocaine hydrochloride (the only form available as a drug) allows smaller amounts to be used compared to previous published studies (20-40 mg vs. 200-500 mg) and no lag time for diffusion. Such a system could provide a controlled release reservoir for lidocaine to adjacent tracheal tissue. This was shown in our pilot study with sustained plasmatic profiles and improved tolerance (decreased pain scores) in the rank order: air group<<lidocaine hydrochloride group<alkalinized lidocaine group.

Adult↗
PubMed2001

The pharmacokinetics and pharmacodynamics of bupivacaine-loaded microspheres on a brachial plexus block model in sheep.

UNLABELLED: We evaluated bupivacaine-loaded microspheres (B-Ms) using a brachial plexus block model in sheep. In the first step, pharmacokinetic characterization of 75 mg bupivacaine hydrochloride (B-HCl) (IV infusion and brachial plexus block) was performed (n = 12). In the second step, a brachial plexus block dose response study of B-HCl was performed with 37.5 mg, 75 mg, 150 mg, 300 mg, and 750 mg. As a comparison, evaluations were performed using a 750-mg bupivacaine base (B). In the third step, evaluations of brachial plexus block were performed with B-Ms (750 mg of B as B-Ms) using two formulations, 60/40 and 50/50 (w/w %); drug-free microspheres were also evaluated. Toxicity evaluations were also performed after IV administration of B-HCl (750 mg and 300 mg), B-Ms (750 mg), and drug-free microspheres (30 mL over 1 min). As the B-HCl dose increased, the time of onset of block decreased and the duration of complete motor blockade increased at the expense of an increase in bupivacaine plasma concentrations. The time of maximum concentration appeared to be independent of the B-HCl dose. In brachial plexus block, a 37.5-mg dose of B-HCl did not induce motor blockade whereas a dose of 750 mg of B-HCl was clinically toxic. In the case of IV administration, doses of 300 mg of B-HCl were as toxic as 750 mg of B-HCl. Compared with the 75 mg of B-HCl administration for brachial plexus block, administration of 750 mg of B as B-Ms increased the duration of complete motor blockade without significant difference in maximum concentration. No significant clinical difference between the two formulations of B-Ms was demonstrated. The IV administration of B-Ms was safe. We conclude that the controlled release of bupivacaine from microspheres prolonged the brachial plexus block without obvious toxicity. IMPLICATIONS: Administration of 750 mg of bupivacaine as loaded-microspheres resulted in prolongation of brachial plexus block in sheep. The peak plasma concentration was not significantly larger than that obtained with 75 mg of plain bupivacaine. The motor blockade was increased more than six times compared with 75 mg plain bupivacaine.

Anesthetics, Local↗
PubMed2000

Tourniquet pain in a volunteer study: effect of changes in cuff width and pressure.

This study examines the relationship between pneumatic tourniquet cuff size, occlusion pressure and the resulting pain. Two tourniquet cuff widths were used, a wide (14 cm) and a narrow cuff (7 cm). Twenty volunteers were divided into two groups for tourniquet application: a pressure group in which the tourniquet was inflated to a pressure equal to the systolic pressure + 100 mmHg, and a saturation group in which the tourniquet was inflated to 10 mmHg above the loss of arterial pulse, as indicated by cessation of pulse waveform on an oximeter. According to a randomised cross-over protocol, subjects were studied using wide and narrow cuffs simultaneously and/or successively on both arms. Pain was assessed by subjects by means of a visual analogue score (0-10 cm). Occlusion pressures were similar for all volunteers in the pressure group and significantly higher than those in the saturation group with both the wide and narrow tourniquets. The wide cuff data turned out to be significantly lower than the narrow cuff results. Subjects in the pressure group could tolerate pain with the narrow cuff for significantly longer than with the wide cuff. However, in the saturation group, volunteers tolerated the wide cuff for longer. Pain intensity increased more rapidly in those in the pressure group with the wide cuff than with the narrow cuff. In contrast, volunteers in the saturation group found the narrow cuff to be more painful than the wide cuff. In conclusion, this study has shown that a wide tourniquet cuff is less painful than a narrow cuff if inflated at lower pressures and at these lower pressures it is still effective at occluding blood flow.

Adult↗
PubMed1996

[Pneumatic tourniquets in orthopedics].

Pneumatic tourniquets, often used to provide a bloodless operating field, carry a risk of adverse effects. Limb exsanguination by gravitation is less aggressive than by mechanical means. Skin, muscles, nerves and vessels suffer maximally under tourniquet because of mechanical pressure, with both a sagittal force, responsible for compression and an axial force responsible for stretchening. All parts of the limb are therefore affected by ischaemia. The restarting of circulation will also increase lesions at the microcirculatory level, responsible for the "no reflow" phenomena. Transient reperfusion intervals are not necessarily beneficial. These effects will significantly contribute to the post tourniquet sensory motor injuries. The tourniquet increases the risk of sepsis. Tourniquet release allows metabolites from the leg to enter into the circulation, and also carries a risk of pulmonary thromboembolism. Carbon dioxide is eliminated by spontaneous hyperventilation under regional anaesthesia. If not eliminated by an increase of mechanical ventilation during general anaesthesia, it may raise intracranial pressure in head trauma patients. Various chemotactic and cytolytic agents may cause lung injury. Mobilization of blood volume at tourniquet placement and release may have detrimental haemodynamic effects in patients with coronary or cardiac insufficiency. The tourniquet increases arterial pressure after 20 to 25 minutes under general anaesthesia. Regional anaesthesia is considered as the technique of choice for the prevention of "tourniquet hypertension", closely linked to pain and relievable by local anaesthetics. Tourniquet modifies also the pharmacokinetics of anaesthetic and other agents. It generates hyperthermia, especially in children. Prospective and comparative studies did not show any advantage as far as duration of surgery and amount of blood loss are concerned. In order to minimize its side effects, the tourniquet must be used within the frame of a strict procedure, with a well adapted and regularly checked equipment. Duration of ischaemia should be as short as possible and not continue for more than two hours, with a reperfusion of 15 minutes every hour. Local hypothermia seems to be a safe means for decreasing side effects.

Blood Loss, Surgical↗
PubMed1996

Use of a pneumatic tourniquet induces changes in central temperature.

Twenty-six patients requiring orthopaedic surgery were anaesthetized and oesophageal and rectal temperature were monitored continuously. Twenty patients requiring a pneumatic tourniquet were allocated prospectively to one of two groups: passive group (Pg) with reflective insulation on all available skin surface (n = 10) and forced group (Fg), with active warming by a forced air system (n = 10). Six patients without a tourniquet were used as a reference group (Rg). The pneumatic tourniquet time was similar in the tourniquet groups. During tourniquet inflation, oesophageal temperature increased with time. The difference was significant compared with the reference group at approximately 20 min. At about 30 min, oesophageal temperature in group Fg was significantly higher than that in group Pg. After tourniquet deflation, temperature decreased transiently. Changes in rectal temperature were similar but delayed significantly. A mechanism to explain the increase in core temperature during pneumatic tourniquet use remains unclear. A redistribution mechanism by cooling of the blood in a cold and vasodilated limb could explain the decrease of temperature after tourniquet deflation.

Adolescent↗
PubMed1995

Prolongation of spinal anesthesia with bupivacaine-loaded (DL-lactide) microspheres.

There is considerable interest in developing a sustained-release local anesthetic formulation to provide long-lasting anesthesia and to decrease systemic toxicity. Bupivacaine (B), 10 mg, loaded in two different types of polylactide microspheres (PLA1 and PLA2) was evaluated after spinal injection and compared with plain bupivacaine (pB), 2 mg. Experiments were performed in six New Zealand rabbits. Duration of motor block was significantly prolonged for PLA1 compared to pB (177.5 +/- 79.5 min vs 44.6 +/- 18.0 min; P < 0.05), as well as for the recovery time (545.0 +/- 299.6 min vs 44.2 +/- 21.5 min; P < 0.05). The duration and recovery were not prolonged for PLA2. Systemic release of B after intrathecal injection was measured from blood samples by using high-performance liquid chromatography. There was no significant difference in maximum B plasma concentration between pB and PLA1 (326 +/- 81 mg/mL vs 321 +/- 57 ng/mL). The time taken to reach the maximum plasma concentration (6.6 +/- 2.6 min vs 41.7 +/- 20.4 min; P < 0.05) was significantly different. This study demonstrated that the use of bupivacaine-loaded (DL-lactide) microspheres can prolong spinal motor block.

Anesthesia Recovery Period↗
PubMed1994

[Intracranial insertion of a nasogastric tube in a patient with severe head injuries].

The accident intracranial insertion of a nasogastric tube is a well known complication. We report the case of 19-year-old girl with a severe craniofacial trauma who had a nasogastric tube inserted at the site of the traffic accident. The aspiration gave issue of haemorrhagic fluid. At admission the X-ray of the skull showed the intracerebral penetration of the tube. It was removed but the patient died two days later. The various means of prevention and treatment of this complication are discussed.

Adult↗
PubMed1991

[Hypothermia helps in the drowned child. Report of a case].

Near-drowning is a leading cause of childhood mortality. Early induction of deep hypothermia has a protective effect on the brain, however. Favorable factors, most marked in early childhood, are both anatomic and physiologic. No parameter capable of predicting good neurologic recovery was identified by a review of the literature. Management rests on internal warming techniques and should be initiated immediately whenever apparent death occurs after exposure to cold. The case of a 29-month-old child who had complete cardiorespiratory arrest and a fall in body temperature to 22 degrees C after near-drowning and who made a full neurologic recovery is reported.

Body Temperature↗
PubMed1989

[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↗