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Biomedical subjects

M A Claeys

Publications and source records attributed to M A Claeys.

14 recordsLinked to original sources
PubMed1996

Total intravenous anesthesia and high-frequency jet ventilation during transthoracic endoscopic sympathectomy for treatment of essential hyperhidrosis palmaris: a new approach.

OBJECTIVE: To evaluate the effects of high-frequency jet ventilation (HFJV) applied to both lungs on hemodynamic parameters, oxygenation, and operating conditions during bilateral videothoracoscopic sympathectomy. DESIGN: A prospective, unblinded study. SETTING: An ambulatory surgical unit at a university medical center. PARTICIPANTS: 30 patients (11 men, 19 women), ASA status 1. INTERVENTION: Bilateral videothoracoscopic sympathectomies were performed using total intravenous anesthesia with propofol, alfentanil, and atracurium, and the patients were ventilated with an oxygen-air mixture using HFJV delivered to both lungs with a Hi-Lo Jet tracheal tube (Mallinckrodt). MEASUREMENTS AND MAIN RESULTS: Mean total anesthesia time was 55 +/- 13 minutes. Hemodynamic parameters remained stable during surgery, although ablation of the sympathetic ganglia induced three incidences of bradycardia (10% of the patients), which were responsive to atropine. Four patients developed oxygen desaturation (Sa O2 < 90%) after the creation of the pneumothorax. Surgical conditions were considered excellent by the surgeons. Concerning postoperative complications, a temporary Horner's syndrome was observed in one patient. Another patient had a mild residual pneumothorax on the first postoperative day that resolved without insertion of a chest tube. CONCLUSIONS: It was concluded that HFJV applied to both lungs is an easy and safe anesthetic technique that provides excellent surgical conditions and causes a minor incidence of morbidity.

Adolescent↗
PubMed1992

Prophylactic diclofenac infusions in major orthopedic surgery: effects on analgesia and acute phase proteins.

The influence of diclofenac, given by continuous i.v. infusion starting preoperatively, on postoperative pain and inflammation was assessed in a double-blind, randomized, placebo-controlled study in 40 patients scheduled for major orthopedic surgery. Starting 30 min before induction the patients received either diclofenac (0.35 mg.kg-1 bolus followed by a constant-rate infusion of 90 micrograms.min-1) or placebo for 24 h. The pain intensity (VAS) and the amount of rescue narcotic (piritramide on demand) were significantly lower in the diclofenac group from 4 and 6 h postsurgery, respectively, till end of infusion. Acute phase proteins used as inflammation markers (C-reactive protein, alpha 1-chymotrypsin, alpha 1-acid glycoprotein, haptoglobin and coeruloplasmin) showed similar variations in both groups for 24 h. The diclofenac treatment had no influence on hematological and coagulation profiles, nor on muscle and liver enzymes in comparison with placebo. Both patients and observer rated the diclofenac treatment as significantly superior to the placebo treatment.

Acute-Phase Proteins↗
PubMed1991

Onset of epidural blockade after plain or alkalinized 0.5% bupivacaine.

This double-blind study investigated the effect of adding 1.4% bicarbonate to 0.5% bupivacaine on onset time of sensory and motor blockade after epidural administration. Forty patients were randomly divided into one of two groups. Group 1 received 20 mL of 0.5% bupivacaine (pH, 5.58 +/- 0.12) and group 2 received 20 mL of 0.5% bupivacaine + 0.6 mL of 1.4% bicarbonate (pH, 6.53 +/- 0.06). Onset of temperature sensation loss occurred at L-1 after 5 min in both groups. The first signs of motor impairment were seen after 4 min in three patients in group 1 and two patients in group 2. Maximum motor blockade was reached after 30 min in group 1 and after 36 min in group 2. No difference in motor blockade or upward spread of anesthesia was noted between the two groups. The authors conclude that alkalinization of 0.5% bupivacaine offers no improvement in the onset of epidural blockade.

Adult↗
PubMed1990

The use of midazolam and flumazenil in locoregional anaesthesia: an overview.

Midazolam is useful as an intravenous supplement to local anaesthesia techniques in producing sedation, amnesia and anxiolysis, and has about five times the sedative potency of diazepam. Considerable interpatient variability exists in dose requirements, especially in elderly patients. The combined effects of local anaesthetics and midazolam may contribute to enhanced haemodynamic effects and changes in the respiratory pattern, impairing ventilation and oxygenation. Flumazenil can be titrated in incremental doses to reverse the residual sedative effects of midazolam, without intrinsic haemodynamic or respiratory effects, but may not fully antagonise the decrease in chemoreceptor sensitivity nor the changes in breathing pattern induced by midazolam. Patients treated with epidural or spinal anaesthesia supplemented with midazolam should be monitored to avoid hypoxaemia risks even after the administration of flumazenil.

Anesthesia, Conduction↗
PubMed1989

Deep sedation for arthroscopic knee surgery.

Deep sedation was explored in a prospective study of 46 consecutive patients as an alternative to local and general anesthesia. All usual arthroscopic surgical procedures could be completely performed with an inflated tourniquet under this type of anesthesia. Hemodynamic and respiratory parameters exhibited only moderate variations, and returned to baseline values less than 15 minutes after surgery. Recovery of consciousness was faster than with general anaesthesia. Patient satisfaction and operative ease were considered better than with local anaesthesia.

Adolescent↗
PubMed1988

Haemodynamic changes during anaesthesia induced and maintained with propofol.

The haemodynamic effects of propofol, given as a single dose of 2 mg kg-1 immediately followed by a continuous infusion of 6 mg kg-1 h-1, were studied in 10 elderly patients premedicated with lorazepam 1 mg i.v. All patients breathed room air spontaneously. Unconsciousness was successfully induced in all patients and persisted during the 60 min of the infusion. Statistically significant decreases in systolic and diastolic arterial pressures were observed 2 min after induction (28% and 19%, respectively) and during infusion (30% and 25%, respectively) and were related to decreases in systemic vascular resistance (21% following induction and 30% during infusion). Cardiac output was not affected at any time nor were stroke volume and heart rate. We conclude that the arterial hypotension associated with the induction and infusion of propofol is mainly a result of a decrease in afterload without compensatory increases in heart rate or cardiac output.

Aged↗
PubMed1988

Reversal of flunitrazepam with flumazenil: duration of antagonist activity.

The duration of action, dose requirements and efficacy of flumazenil, a specific benzodiazepine antagonist, were evaluated in 50 patients scheduled for orthopaedic surgery under local anaesthesia and flunitrazepam sedation. Fifteen minutes after injection of flunitrazepam 0.03 mg kg-1 the patients received placebo or flumazenil i.v. in a randomized, double-blind and titrated fashion. At selected time intervals, sedation, anterograde amnesia, muscular hypotonia, orientation in time and space, comprehension and collaboration were evaluated. Compared with placebo, flumazenil promptly reversed sedation for 30 min, hypotonia for 45 min and anterograde amnesia for 60 min, and improved orientation and collaboration for 60 min. However, after 90 min significant recurrent sedation was observed, while anterograde amnesia reappeared after 60 and up to 120 min. No side-effects were noted at any time. The dose of flumazenil required for reversal of flunitrazepam sedation was 0.35 +/- 0.15 mg (mean +/- SD).

Adult↗
PubMed1986

Efficacy of lorazepam and lormetazepam as intravenous premedicants for anesthesia and surgery.

Lorazepam 4 mg and lormetazepam 2 mg were compared as intravenous premedicants by assessing their effects on the level of consciousness and anxiety, sensory and motor functions, neuromuscular function and vital parameters in sixty surgical patients in a randomized study. Lormetazepam exerted a marked sedative-hypnotic effect maximal at 10 min. Lorazepam had a slower onset of action with a peak effect at 40 min on the different neurobehavioral functions but seemed to induce a longer duration of sedation and a more consistently obtunded awareness of perisurgical events than lormetazepam. Sensory functions were similarly affected by both drugs. Motor function was significantly more impaired by lormetazepam than by lorazepam (P 0.05). Both drugs significantly decreased anxiety for at least 60 min after premedication. Important changes of muscle tone were noticed with lormetazepam at 10 to 30 min resulting in upper airway obstruction in some patients. All hemodynamic changes remained clinically acceptable in both groups and no side effects were seen. The clinical anesthesiologists rated the quality of premedication as unsatisfactory in 7% of the patients treated with lorazepam and in 27% of those receiving lormetazepam. Together with its milder neurobehavioral effects and highly effective anxiolytic action, these factors favor the use of lorazepam for anesthetic premedication despite a relatively slow onset of action.

Adult↗
PubMed1986

Midazolam for intramuscular premedication: dose-effect relationships compared to diazepam, fentanyl and fentanyl-droperidol in a placebo controlled study.

The clinical effects of midazolam (7.5, 10 and 15 mg), diazepam 10 mg, fentanyl 0.1 mg and fentanyl 0.1 mg-droperidol 5 mg, administered intramuscularly for surgical premedication, were compared in a double-blind placebo-controlled study. The degree of sedation provided by midazolam was significantly superior to diazepam, fentanyl or placebo. The largest dose of midazolam also impaired the lucidity of the patients and induced a moderate degree of muscular hypotony. A dose-effect relationship was observed only for the sedative effects of midazolam 60 min after administration. Midazolam scored consistently better than diazepam, fentanyl, placebo and fentanyl-droperidol for incidence of amnesia, stability of cardiovascular measurements and physician's acceptance. In all treatment groups, including placebo, anxiety decreased significantly with time. However, if expressed as percentage change, the greatest decrease occurred in the midazolam 15 mg group compared to all other treatments. Midazolam appeared to be a more effective premedicant than diazepam, analgesics or placebo. The intensity of the combined central nervous system effects suggested the dose of 10 mg might be the most suitable for intramuscular premedication.

Adolescent↗
PubMed1985

Ciramadol. The therapeutic dose range during balanced anesthesia.

In this study we attempted to determine whether ciramadol, a mixed opioid agonist-antagonist, would provide a satisfactory analgesic supplementation to an anesthetic technique for major surgery. Fourteen surgical patients received a balanced anesthesia technique with nitrous oxide, oxygen and muscle relaxants following thiopental induction. Incremental doses of ciramadol were administered as indicated by the somatic, hemodynamic or other sympathetic responses to anesthetic and surgical stimulations. The mean requirements of ciramadol during surgery were inferred from each patient's time-dose curve. The mean loading dose of ciramadol needed was 2.5 +/- 0.4 mg/kg and for maintenance of the analgesic effects, ciramadol had to be administered at a rate of 0.41 +/- 0.09 mg/kg.h. The important transformation rate (50.4%/h) was suggestive of an analgetic ceiling effect. Despite the very large amounts of ciramadol given, the hemodynamic responses to noxious stimuli were not fully suppressed with hypertensive episodes occurring during surgery. Recovery of spontaneous ventilation appeared promptly after completion of surgery and no evidence of respiratory depression was seen. Minute ventilation, respiratory rate and arterial PaCO2 remained within normal limits up to two hours after the end of anesthesia. No incidence of adverse psychotomimetic effects was observed.

Adult↗
PubMed1985

Infusion of propofol ('Diprivan') as sedative technique for colonoscopies.

Sixty male and female patients, scheduled for colonoscopy were premedicated with glycopyrrolate 0.4 mg intramuscularly. Anaesthesia was induced with 2 mg/kg propofol ('Diprivan') and maintained with a continuous infusion of propofol at a rate of 3, 6 or 9 mg/kg/h randomly allocated. Patients lost consciousness within 60.6 +/- 18.7 (s.d.) s. Preservation of the hypnotic effect was infusion-rate dependent as 15, 40 and 85% of the patients were unconscious on infusion rates of 3, 6 or 9 mg/kg/h propofol, respectively. A high degree of sedation was observed in the remaining patients with an incidence of 40, 35 and 0% in the different series. Sedation was light in the remainder of the patients. To increase the acceptability of the procedure, a supplemental bolus of propofol and/or an increase in the infusion rate were required in 40, 15 and 10% of the 3, 6 and 9 mg/kg/h infusion rate groups, respectively. The incidence of amnesia was similar in all three groups (80, 90 and 95%, respectively). Recovery was significantly longer with increasing infusion rate, but remained rapid. The longest time was 7.3 +/- 4.0 min to open eyes on command and 10.6 +/- 4.6 min to answer correctly. The most important side effects were pain on injection (50%) and some restlessness during maintenance (25%). Blood pressure decreased, but heart rate was unaffected. Patients breathed room-air spontaneously. Respiratory rate slowed after induction then increased rapidly above baseline values. The incidence of apnoea was 48% with a mean duration of 51 +/- 22s (s.d.). The technique was evaluated as good or adequate in 95% of the cases. We suggest than an analgesic premedication followed by an average of 6 mg/kg/h propofol by infusion might be a simple and convenient method of achieving good conditions for colonoscopy.

Anesthesia Recovery Period↗
PubMed1985

Ciramadol as analgesic adjunct to anesthesia in short surgical procedures.

The present study was undertaken to assess the intensity and duration of analgesic effect of ciramadol during induction and maintenance of general anesthesia for short surgical procedures. Sixty female patients received either ciramadol 2 mg.kg-1 or saline before anesthesia induction with thiopental-succinylcholine followed by enflurane maintenance. The changes in heart rate following intubation and surgical incision were partially obtunded by ciramadol pretreatment but mean arterial pressure remained significantly elevated till 6 min. post surgical incision. No evidence of impairment of the spontaneous ventilation was observed even when enflurane anesthesia was added. Addition of enflurane also had no deleterious effects on the cardiovascular performance in the ciramadol treatment group. In the absence of pretreatment with ciramadol, the higher concentrations of enflurane needed induced a significantly lower blood pressure but the rise in heart rate observed remained notably larger than in the ciramadol group. This was accompanied by a reduction of spontaneous ventilation as evidenced by the decrease of minute volume. With both techniques end-tidal carbon dioxide tensions rose to the same extent. Maintenance of adequate anesthesia required a larger amount of enflurane in the non-pretreated group. This could indicate an anesthesia sparing effect of ciramadol.

Adult↗
PubMedDate not supplied

Thoracic epidural bupivacaine-fentanyl anesthesia for percutaneous cholecystolithotomy in high-risk patients.

BACKGROUND AND OBJECTIVES: The efficacy of a thoracic epidural block was assessed in 12 high-risk patients scheduled for elective percutaneous cholecystolithotomy. METHODS: A thoracic epidural catheter was inserted at level T8-9. The amount of 0.5% bupivacaine to block two thoracic epidural segments was calculated, adapted to age, height, and epidural level, and administered with 50 micrograms fentanyl. Hemodynamic and respiratory variables and patients' pain and movement were assessed throughout the procedure. RESULTS: Anesthesia was obtained with a minimal dose of local anesthetic. All patients were satisfied with this method. Neither hemodynamic nor respiratory impairment were observed after epidural injection. However, vagal reactions reported in other studies occurred in two patients upon puncture of the gallbladder. CONCLUSIONS: This minimally invasive anesthetic technique seems to be a good alternative for high-risk patients. However, careful monitoring of heart rate and blood pressure remains mandatory throughout the procedure.

Adult↗