Search PubMed⌕ Search

Biomedical subjects

G Rolly

Publications and source records attributed to G Rolly.

At least 37 records · Page 2Linked to original sources
PubMed1998

Influence of anaesthesia on defibrillation threshold.

Internal cardioverter-defibrillator implantation can be performed under local or general anaesthesia. Whether the technique of general anaesthesia influences the defibrillation threshold remains a matter of debate. We therefore compared, in a prospective, randomised clinical study, the effect of intravenous anaesthesia using propofol with inhalational anaesthesia using isoflurane on the defibrillation threshold in 68 patients scheduled for transvenous single-lead internal cardioverter-defibrillator implantation. Defibrillation threshold was measured at implantation and at device testing 1 week and 1 month after implantation. Patients acted as their own controls. Neither the anaesthetic technique nor the duration of anaesthesia was associated with significant changes in the defibrillation threshold. We conclude that in this group of high-risk patients, both types of anaesthesia are acceptable techniques for internal cardioverter-defibrillator implantation and testing.

Anesthesia, General↗
PubMed1998

Haemodynamic and electroencephalographic response to insertion of a cuffed oropharyngeal airway: comparison with the laryngeal mask airway.

We have compared the cuffed oropharyngeal airway (COPA), a modified Guedel airway device with a specially designed cuff at its distal end, with the laryngeal mask airway (LMA), on haemodynamic and electroencephalographic (EEG) responses to insertion. In addition, we examined the haemodynamic and EEG changes during initiation of the effect-compartment controlled infusion. We studied 35 female patients undergoing ambulatory gynaecological surgery allocated randomly to received an LMA or COPA to manage the airway. After premedication with midazolam 0.03 mg kg-1 i.v. and low-dose alfentanil (0.01 mg kg-1), anaesthesia was induced and maintained with propofol, using an effect-compartment controlled infusion set at an effect-site concentration of 4 micrograms ml-1. After intercompartmental equilibration, the LMA (group I) or COPA (group II) was inserted and haemodynamic (arterial pressure, heart rate) and EEG (bispectral index (BIS)) responses to insertion studied. The effect-compartment controlled infusion of propofol caused only mild haemodynamic changes during induction. Changes in arterial pressure and heart rate after insertion were similar in both groups and not significantly different from baseline values before insertion. Changes in BIS after insertion were minor and similar between groups.

Ambulatory Surgical Procedures↗
PubMed1998

Clinical usefulness of the bispectral index for titrating propofol target effect-site concentration.

The bispectral index, a new processed electroencephalographic parameter which may give information on depth of anaesthesia, was used in 58 patients undergoing outpatient gynaecological surgery in order to study if the addition of bispectral index monitoring to standard clinical monitoring could improve the titration of target propofol concentration when using effect-site target-controlled propofol infusion for sedation. In Group 1 (n = 30), the bispectral index was recorded but the anaesthetist was unaware of the readings and therefore only classical signs of depth of anaesthesia were used to guide the anaesthetist in controlling the effect-site concentration. In Group 2 (n = 28), bispectral index readings were available to the anaesthetist and effect-site concentration was adjusted to ensure that bispectral index was maintained between 40 and 60. Similar propofol induction and maintenance doses, blood and effect-site concentrations and mean bispectral index were found in the two groups. A greater percentage of bispectral index readings lying outside the target range (i.e. < 40 or > 60) and more movement at incision and during maintenance were found in Group 1. There was a trend towards more implicit awareness in patients in Group 1. Bispectral index was found to be useful for measuring depth of sedation when using propofol target-controlled infusion. Propofol dosage could not be decreased but a more consistent level of sedation could be maintained due to a more satisfactory titration of target effect-site concentration.

Adolescent↗
PubMed1998

Influence of pre-anaesthetic medication on target propofol concentration using a 'Diprifusor' TCI system during ambulatory surgery.

The effects of pre-anaesthetic medication on target propofol concentration, induction dose, time to induction, and discomfort on infusion were studied in 45 female patients undergoing ambulatory gynaecological procedures using 'Diprifusor' target controlled infusion of propofol. The patients were randomly allocated to receive either no premedication (group 1) or premedication with diazepam alone (group 2) or in combination with alfentanil (group 3). Induction was more successful in premedicated than unpremedicated patients with an initial target propofol concentration of 4 micrograms.ml-1 (87% in group 2 and 93% in group 3 vs. 38% in group 1, p < 0.01). Premedication was also associated with the requirement of a lower mean target concentration for induction, a lower induction dose and a shorter time to induction. There were no significant between-group differences in discomfort on infusion or target concentration during maintenance. For short ambulatory procedures, the recommended initial target concentration of propofol is 4 micrograms.ml-1 in premedicated and 6 micrograms.ml-1 in unpremedicated patients.

Adult↗
PubMed1998

Comparison of spontaneous frontal EMG, EEG power spectrum and bispectral index to monitor propofol drug effect and emergence.

BACKGROUND: The aim of this study was to investigate the accuracy of frontal spontaneous electromyography (SEMG) and EEG spectral edge frequency (SEF 95%), median frequency (MF), relative delta power (RDELTA) and bispectral index (BIS) in monitoring loss of and return of consciousness and hypnotic drug effect during propofol administration at different calculated plasma target concentrations. METHODS: Propofol was administered by using a target-controlled infusion at different propofol steady-state concentrations. All variables were measured simultaneously at specific calculated concentrations and endpoints. RESULTS: Loss of consciousness was accurately monitored by BIS, SEMG and SEF 95%, and propofol drug effect by BIS only. Return of consciousness was predicted by BIS, MF and SEF 95%. Due to the biphasic EEG pattern of propofol and the lack of reproducible data at specific propofol concentrations, the clinical usefulness of SEF 95%, MF and RDELTA was very limited. SEMG was useful to detect loss and return of consciousness, but without predictive value. CONCLUSIONS: The BIS might be an accurate measure to monitor depth of anaesthesia and hypnotic drug effect. Other neurophysiologic measures have limited value to monitor depth of anaesthesia and hypnotic drug effect.

Adult↗
PubMed1998

Dual channel electrostimulation in pain.

Spinal cord stimulation is an accepted treatment for neuropathic pain. Technical advances in electrode design and better patient selection have led to better and sustained pain control by these devices. Multilead electrical stimulation is the latest innovation in implantable electrostimulation (Mattrix, Medtronic Minneapolis, USA). Two combined multipolar leads connected to a radiofrequency--coupled system can deliver electrical pulses of various amplitudes and pulse widths at different dermatome levels. Single stimulation is applied with different electrode configurations using both electrodes with identical stimulation parameters. In dual stimulation, the amplitude and the pulse width can vary between the electrode configurations. Dual channel stimulation helps steering stimulation paresthesias. Three patients illustrate the technical advantages of dual channel electrostimulation in the pain relief at multiple sites. Two patients with failed back surgery syndrome obtained more easily stimulation-induced paresthesias in the back and the legs. Dual channel stimulation is cost saving in patients implanted with two electrodes. This is presented in a third patient with an electrode in the thalamus--as pain treatment for cervicobrachialgia and a second in the epidural space--as treatment for the failed back surgery syndrome. These electrodes were connected to the Mattrix stimulator.

Adult↗
PubMed1997

Spinal cord stimulation: a valuable treatment for chronic failed back surgery patients.

Spinal cord stimulation (SCS) has been used in the treatment of "chronic failed back surgery syndrome" for many years. To evaluate long-term results and cost effectiveness of SCS, we interviewed 69 patients treated during a period of 13 years. Twenty-six patients stopped using SCS; there was no clear explanation for this unsatisfactory result in 10. Forty-three patients continued with the therapy and obtained good pain relief. Electrode breakage either spontaneous or due to a procedure to obtain better stimulation paresthesias was more frequent in the radiofrequency-coupled system group than in the battery group (mean +/- SEM 2.81 +/- 2.0 versus 1.42 +/- 1.51, respectively; P = 0.0018). Ten patients obtained better pain relief than during the trial procedure. Some still need opioid analgesics, but 11 of the 16 who require these drugs obtained a synergistic effect when concomitantly using the stimulator. Eleven patients have returned to work. In our center, the application of SCS costs on average $3660 per patient per year. Although this seems expensive, it may be a cost-effective treatment if other therapies fail.

Adult↗
PubMed1997

Palliative care: knowledge and attitudes of general practitioners: the results of a questionnaire after training.

A questionnaire about attitudes and knowledge in palliative care treatment was sent to 185 general practitioners who participated such a seminar some months before. The response rate was low (69/185). Pain is the most frequent symptom. All the responding doctors assume they can treat pain adequately. However, none of them can answer the knowledge questions correctly. They appreciate the palliative care organizations for the help in symptom control or for difficulties in psychological symptoms. A multifactorial etiology might explain the difficult control of asthenia. This survey agrees with other studies that knowledge in symptom control and palliative care should be improved.

Analgesics, Opioid↗
PubMed1997

Comparison of computer-controlled administration of propofol with two manually controlled infusion techniques.

Ninety women were studied in order to compare dose requirements and quality of anaesthesia between target-controlled infusion and two manually controlled infusion schemes for propofol administration: group I received target-controlled infusion for induction (4 micrograms.ml-1 target blood concentration, increased by 2 micrograms.ml-1 after 3 min of consciousness not lost), groups II and III received an induction bolus of propofol at infusion rates of 1200 or 600 ml.h-1, respectively, until loss of consciousness. Anaesthesia was maintained with propofol target-controlled infusion in group 1 or by constant rate infusion in the other two groups. Computer simulations were used to calculate blood and effect-site propofol concentrations. Mean induction times (SD) were 78 (65)s in group I versus 51 (10)s and 62 (12)s in groups II and III, respectively (p < 0.05 between groups II and III). Mean induction doses were: 1.31 (0.44), 2.74 (0.56) and 1.77 (0.43) mg.kg-1 and mean maintenance doses were 13.4 (3.55), 9.32 (1.72) and 9.97 (1.53) mg.kg-1 h-1 in groups I, II and III, respectively (p < 0.05 between all groups). There was a lower incidence of apnoea in group I than in groups II and III. There were no significant differences between the groups in other objective parameters of anaesthetic quality studied. Computer simulations showed an "overshoot' in propofol blood and effect-site concentration with manual induction and significantly higher maintenance levels with target-controlled infusion.

Adult↗
PubMed1997

In vitro evaluation of the effect of profound haemodilution with hydroxyethyl starch 6%, modified fluid gelatin 4% and dextran 40 10% on coagulation profile measured by thromboelastography.

Synthetic colloids have been implicated as a cause of coagulopathy when administered in large quantities. The effect of profound haemodilution (50%) on coagulation profile was measured in vitro by thromboelastography. Blood samples were taken from 11 ASA grade 1 patients prior to induction of anaesthesia for elective surgery. Each sample was simultaneously tested in four different preparations: undiluted blood (control sample); blood diluted with hydroxyethyl starch 6%; blood diluted with modified fluid gelatin 4%; blood diluted with dextran 40 10%. There was a significant decrease in reaction time in the preparations treated with hydroxyethyl starch 6% and modified fluid gelatin 4%, reflecting activation of initial fibrin formation. A significant increase in clot formation time was noted in the hydroxyethyl starch 6%-treated preparations. There was also a significant decrease in clot formation rate and maximum amplitude in the hydroxyethyl starch 6% group. Clot formation time, clot formation rate and maximum amplitude did not change in the modified fluid gelatin 4% group. Profound haemodilution with dextran 40 10% exerted extreme effects on the measured variables, very often resulting in a straight line on the thromboelastography profile.

Blood Coagulation↗
PubMed1996

Anaesthesiological manpower in Europe.

Information about physician anaesthesiologist manpower in the countries of the European Union was collected from questionnaires sent to the delegates representing their respective countries on the European Board of Anaesthesiology. In the countries of the European Union and Switzerland and Norway 40,259 specialist anaesthesiologists are recorded. The number of anaesthesiologists in relation to population varies between as little as 4.4 and 4.6 (Ireland and UK) and as many as 15.6 (Italy), with a mean of 10.8/100,000 inhabitants. There are 11,610 physicians recorded in training in anaesthesiology. The ratio of trainees to specialists in the European Union countries was 28.8/100, varying from as low as 6.5 in France, to as high as 96.7 and 98/100 in Ireland and the UK respectively. These figures indicate a wide difference in the numbers of specialists and trainees between the European countries studied. However, the overall mean figure is close to that reported in the USA (9.2/100,000).

Adult↗
PubMed1996

Evaluation of the anticoagulant properties of aprotinin in vitro.

The interaction of aprotinin with normal coagulation was studied in blood samples obtained from 10 healthy subjects. Each sample was simultaneously tested in four different preparations: NaCl-treated blood: 0.03 mL 0.9% NaCl in 0.33 mL blood; aprotinin treated blood: 0.33 mL blood+aprotinin in 0.03 mL in aliquots to obtain a final blood concentration of respectively 50 KIU mL-1; 100 KIU mL-1 and 200 KIU mL-1. The coagulation process was analysed by thromboelastography. R-time, reflecting intrinsic coagulation, increased in a dose dependent manner between NaCl-treated and aprotinin-treated blood. These findings suggest a dose dependent impairment of intrinsic coagulation by aprotinin.

Anticoagulants↗
PubMed1996

Infra-red thermographic evaluation of spinal cord electrostimulation in patients with chronic pain after failed back surgery.

This study sought to visualize spinal-cord stimulation activity by infra-red thermography in humans suffering from chronic lumbosciatic pain. All the patients had previously undergone neurosurgery for a herniated intervertebral disc. Temperature changes were evaluated in two defined body areas after starting, stopping, maintaining or not starting the stimulation. In one body area, corresponding to the pain location, the patient experienced stimulation paraesthesia, whereas in the non-painful (second) area no stimulation paraesthesia were present. The patients were studied on four consecutive days with a randomly chosen stimulation pattern. Temperature changes in identical and comparable skin areas were measured and statistically analysed. No statistically significant temperature variation was found between the painful and non-painful areas. These findings do not confirm the idea that spinal cord stimulation induces vasodilation in the affected pain area when stimulation is present. Infra-red thermography is not able to differentiate the stimulated from the non-stimulated areas.

Adult↗
PubMed1996

Nightmares and hallucinations after long-term intake of tramadol combined with antidepressants.

Tramadol is a weak opioid with effects on adrenergic and serotonergic neurotransmission that is used to treat cancer pain and chronic non malignant pain. This drug was initiated in association with paroxetine and dosulepine hydrochloride in a tetraparetic patient with chronic pain. Fifty-six days after initiation of the treatment the patient presented hallucinations that only stopped after the withdrawal of psycho-active drugs and tramadol. The case report questions the long term use of pain killers combined with psycho-active drugs in chronic non malignant pain, especially if pain is under control.

Aged↗
PubMed1996

Accumulation of foreign gases during closed-system anaesthesia.

In a previous study, accumulation of methane was found at the end of closed-system ventilation. As on-line analysis of gas concentrations is now available, we examined the progressive increase in concentrations of methane, carbon monoxide and acetone during modern, closed-system conditions, and their influence on infrared halothane analysis, in 26 non-pregnant, gynaecological patients. A computer-controlled closed-system anaesthesia apparatus (PhysioFlex) was used for ventilation during total i.v. anaesthesia (excluding nitrous oxide or potent inhalation anaesthetics) for gynaecological laparoscopy. Methane, carbon monoxide and acetone concentrations were analysed every 15 min in a photoacoustic infrared monitor and halothane concentrations by built-in infrared spectrometry. Mean methane concentrations increased progressively after 105 min to 941 (SD 1094) ppm, but concentrations of carbon monoxide and acetone did not increase significantly. In 18 patients, the infrared measurement falsely indicated 0.79 (0.52)% "halothane" after 60 min, but no reading appeared in the other eight patients. We conclude that methane accumulated progressively under strict closed-system conditions in higher concentrations than reported previously. In two-thirds of patients it induced false "halothane" readings.

Acetone↗