Biomedical subjects
A Borgeat
Publications and source records attributed to A Borgeat.
[Antiemetic effect of propofol].
Propofol is known to possess direct antiemetic effects. Its use for induction and maintenance of anaesthesia has been shown to be associated with a lower incidence of postoperative nausea and vomiting (PONV) when compared to any other anaesthetic drug or technique. However, its mechanism of action in this context is still not well understood. In this article, the best ways to take advantage of propofol's antiemetic properties are emphasized. The possible effects of propofol on the cerebral cortex, its interactions with the dopaminergic and the serotoninergic systems are evaluated by the known clinical and basic science results. Finally, the advantages and disadvantages of using propofol to decrease the incidence of PONV in clinical practice are discussed.
Propofol and asepsis: is it safer to use the TCI technique?
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Patient-controlled interscalene analgesia with ropivacaine after major shoulder surgery: PCIA vs PCA.
We have compared the efficacy of patient-controlled interscalene analgesia (PCIA) using ropivacaine with patient-controlled analgesia (PCA) using nicomorphine in 60 patients (n = 30 in each group), in a prospective, randomized study. In both groups, all patients received interscalene block with 0.75% ropivacaine before induction of anaesthesia. Six hours after interscalene block, patients in group PCIA received continuous infusion of 0.2% ropivacaine at a rate of 5 ml h-1 with a bolus dose of 3 or 4 ml and a lockout time of 20 min; patients in group PCA received continuous infusion of nicomorphine 0.5 mg h-1 and a bolus dose of 2 or 3 mg with a lockout time of 20 min. Control of pain was significantly better from 12 to 48 h after operation (except at 42 h) in group PCIA. Nausea and pruritus occurred significantly more frequently in group PCA. Patient satisfaction was greater in group PCIA. We conclude that the use of 0.2% ropivacaine using PCIA was an efficient way of managing pain after major shoulder surgery and compared favourably with PCA nicomorphine in terms of pain relief, side effects and patient satisfaction.
Anesthesia in a patient with malignant systemic mastocytosis using a total intravenous anesthetic technique.
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Convulsions induced by ropivacaine during interscalene brachial plexus block.
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Gynecologic laparoscopic surgery is not associated with an increase of serotonin metabolites excretion.
UNLABELLED: Gynecologic laparoscopic surgery is associated with a high incidence of postoperative nausea and vomiting (PONV). The specific antagonists of the 5-hydroxytryptamine-3 (5-HT3) receptor have been progressively introduced in anesthesiology to prevent or treat PONV. Although a large increase of serotonin has been documented after cisplatin treatment, the link between serotonin and PONV in surgery/anesthesiology is unknown. In a prospective study, we compared the excretion of the serotonin metabolite 5-hydroxyindoacetic acid (5-HIAA) in 40 women undergoing either gynecologic laparoscopic surgery (laparoscopy group) or traditional open laparotomy surgery (laparotomy group). Premedication, anesthetic technique, and postoperative pain treatment were standardized. The excretion of 5-H IAA corrected to creatinine was measured in all patients immediately after the induction of anesthesia and was repeated regularly until 9 h after induction. The excretion of 5-HIAA/creatinine was similar in the two groups; no increase was observed in either group. The incidence of nausea and vomiting was 40% and 35%, respectively, in the laparoscopy group versus 60% and 15%, respectively, in the laparotomy group (not significantly different). The excretion of 5-HIAA/creatinine was comparable in patients of both groups among those who vomited and those who did not. We conclude that the creation of a pneumoperitoneum during gynecologic laparoscopic surgery is not associated with an increase of 5-HIAA excretion. PONV after gynecologic laparoscopic surgery is not explained by an increase of serotonin secretion. IMPLICATIONS: The mechanism leading to the high incidence of postoperative nausea and vomiting after gynecologic laparoscopic surgery is unknown. The excretion of the serotonin metabolite 5-hydroxyindoacetic acid did not increase during the creation of the pneumoperitoneum and the first 9 h postoperatively. Increase of serotonin secretion from the gut may not explain postoperative nausea and vomiting associated with this surgery.
Nausea and vomiting after spinal anaesthesia with morphine.
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Hyperemesis gravidarum: is serotonin implicated?
Serotonin excretion was investigated in the nausea and vomiting associated with hyperemesis gravidarum. Urinary hydroxyindoleacetic acid was measured in 13 gravid women with hyperemesis gravidarum, 10 gravid women without nausea and vomiting, and 10 nongravid women of similar age not taking contraceptive pills. No significant difference in the urinary excretion of hydroxyindoleacetic acid was found among the groups. Hyperemesis gravidarum is not associated with an increase of serotonin secretion.
Spontaneous movements associated with rocuronium injection: the effects of prior administration of fentanyl.
STUDY OBJECTIVE: To determine if prior injection of fentanyl decreases the incidence of spontaneous movements during rocuronium administration. DESIGN: Prospective, randomized, double-blind, placebo-controlled study. SETTING: University orthopedic surgical center. PATIENTS: 122 ASA physical status I and II patients scheduled for elective orthopedic surgery. INTERVENTIONS: Patients randomly received 2 micrograms/kg of fentanyl or the equivalent volume of NaCl 0.9% 45 seconds prior to induction of anesthesia. Induction was performed with propofol 2.5 mg/kg followed by rocuronium 0.8 mg/kg 60 seconds later. Spontaneous movements were scored as follows: a) limited to the hand, b) limited to the elbow, and c) involving the whole arm, including the shoulder. MEASUREMENTS AND MAIN RESULTS: Prior injection of fentanyl (2 micrograms/kg significantly decreased the incidence of spontaneous movements limited to the hand: 5% versus 20% (p < 0.05); limited to the elbow: 1% versus 25% (p < 0.05); and involving the whole arm: none versus 12% (p < 0.05). No erythema or any change in the skin surrounding the point of injection of the involved arm was observed. Twenty-four hours later, no vein induration was present and no patient complained of any residual pain. CONCLUSION: Prior injection of fentanyl significantly decreases the incidence of spontaneous movements associated with rocuronium administration.
Induction characteristics of 2% propofol in children.
We have conducted a prospective, randomized study to evaluate the characteristics of induction of anaesthesia in children with 2% propofol. Children were allocated to receive propofol 3 mg kg-1 (group A), 4 mg kg-1 (group B) or 5 mg kg-1 (group C) of the 2% formulation. We observed a high incidence of spontaneous movements (90%) in group A and an incidence of coughing of 70% in group C. Induction in group B was characterized by a short induction time, low incidence of spontaneous movements (20%), pain on injection (10%) and excellent conditions for manual ventilation.
Spontaneous movements associated with rocuronium: is pain on injection the cause?
Spontaneous movements are sometimes observed of the arm into which rocuronium is administered. In order to assess a possible relationship between these movements and pain, we injected in 10 awake, ASA I patients, in a double-blind manner, both rocuronium 1 ml (10 mg) and 0.9% NaCI 1 ml (placebo), with a 30-s interval in between. None of the patients receiving placebo complained of pain, but eight of 10 patients reported a strong burning pain during injection of rocuronium with brisk flexion of the elbow and wrist, similar to those observed in patients after induction of anaesthesia. A second injection of rocuronium did not produce such pain and no movements were observed. We conclude that injection of rocuronium is associated with severe, burning pain of short duration, responsible for the spontaneous movements in the arm observed after induction of anaesthesia.
Subhypnotic doses of propofol do not possess antidopaminergic properties.
In order to investigate the possible interactions of propofol with the dopaminergic system, a prospective, randomized, double-blind, placebo-controlled study was performed on the profile of prolactin secretion, since prolactin blood levels are known to increase when dopaminergic receptors are blocked. Ten fasting female patients scheduled to receive cancer chemotherapy were allocated to receive either propofol at a rate of 1 mg.kg-1.h-1 or Intralipid 0.1 ml.kg-1.h-1. The study included two consecutive chemotherapy cycles; each patient received in a random order propofol or Intralipid. The infusions were started 4 h prior to induction of chemotherapy; prolactin blood levels were determined at time 0, 30, 60, 120, and 240 min (end of the study period). The basal prolactin blood levels were 14.2 +/- 4.3 vs 12.8 +/- 2.7 and 10.7 +/- 1.7 vs 14.0 +/- 3.6 ng/mL at the end of the study for propofol and Intralipid, respectively. These results suggest that the antiemetic properties of propofol are not mediated via interactions with the dopaminergic system.
Patient-controlled analgesia after major shoulder surgery: patient-controlled interscalene analgesia versus patient-controlled analgesia.
BACKGROUND: The authors compared patient-controlled interscalene analgesia (PCIA) with local anesthetics with intravenous patient-controlled analgesia (PCA) with opioids to manage postoperative pain after major shoulder surgery. METHODS: Forty patients scheduled for elective major shoulder surgery were prospectively randomized to receive either PCIA or PCA. Before surgery, all patients had an interscalene block. In the PCIA group, a catheter was introduced within the interscalene sheath. Six hours after the initial block, patients received for 48 h either a continuous infusion of 0.15% bupivacaine through the interscalene catheter at a rate of 5 ml/h plus a bolus of 3 or 4 ml with a lock-time of 20 min (group PCLA) or a continuous intravenous infusion of nicomorphine at a rate of 0.5 mg/h plus a bolus of 2 or 3 mg with a lock-time of 20 min (group PCA). Pain relief was regularly assessed using a visual analog scale, side effects were noted, and the patients were asked to rate their satisfaction at the end of the study. RESULTS: Pain relief was significantly better controlled in the PCIA group at t = 12 and 18 h (P < 0.05). Vomiting and pruritus were 0 versus 25% and 0 versus 25% for the PCIA and PCA groups, respectively (P < 0.05). Patient satisfaction was greater in the PCIA group (P < 0.05). Time of first bolus administration and paracetamol supplement were similar in both groups. CONCLUSIONS: The use of the PCIA technique was uncomplicated and provided better pain relief than PCA during the first 18 h after operation. The incidence of side effects such as vomiting and pruritus was significantly decreased with the use of PCIA, and patient satisfaction was superior in the PCIA group.
Propofol: pro- or anticonvulsant?
The pro- or anticonvulsant properties of propofol remain a matter of controversy. Although numerous case reports describe the appearance of abnormal movements, posturing and seizure-like activity related to the use of propofol, systematic studies in both humans and animals strongly suggest that it possesses antiepileptic properties. Propofol consistently reduces the seizure duration during electroconvulsive therapy, its use has been successful in controlling refractory status epilepticus and in animals it offers a strong protection against lignocaine- or pentylene-tetrazol-induced epilepsy. The beneficial effects of propofol may be related to its uniform depressant action on the central nervous system, to a potentialization of GABA-mediated pre- and postsynaptic inhibition, and by decreasing the release of excitatory transmitters, glutamate and aspartate.
Pain on injection of propofol.
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Survival after cardiac arrest and severe acidosis (pH = 6.54)
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Spontaneous movement, propofol and dopamine receptors.
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