PubMed Health⌕ Search

Biomedical subjects

J P Tétrault

Publications and source records attributed to J P Tétrault.

At least 19 recordsLinked to original sources
PubMed2001

Diurnal variation of episcleral venous pressure in healthy patients: a pilot study.

PURPOSE: To study diurnal episcleral venous pressure (EVP) and its relation to intraocular pressure (IOP) in healthy patients. The influences of supine position and lid closure on EVP were also studied. DESIGN: Experimental observational study. PARTICIPANTS AND METHODS: Twelve healthy patients with no eye disease had their IOP and EVP measured at 16h00, 22h00, 22h30, 06h00, 06h30, 09h00, 12h00, and 16h00. Measurements at 22h30, 06h00, and 06h30 were performed on supine patients, and the measurement at 06h00 was with the eye that had been closed for the whole night. In a second experiment, EVP was measured on patients who were lying supine from 22h30 to 16h00 with one eye closed during the day. MAIN OUTCOME MEASURES: Episcleral venous pressure and IOP at varying time points during a 24-hour period. RESULTS: Episcleral venous pressure was relatively constant throughout the day except for a slight reduction at 22h00. After lying down, the EVP increased by 3.6 mm Hg and remained increased as long as the patient remained in this position. Eyelid closure did not affect EVP. IOP measured with the Tono-Pen closely followed the variations in EVP. CONCLUSION: Episcleral venous pressure remains relatively constant throughout the day. It increases in the supine position with a corresponding increase in IOP. Lid closure does not influence EVP or IOP.

Circadian Rhythm↗
PubMed2000

Onset of spinal block is more rapid with isobaric than hyperbaric bupivacaine.

PURPOSE: To compare isobaric with hyperbaric 9.75 mg bupivacaine injected intrathecally, and to evaluate the effects of subsequent injection of lidocaine 2% into the epidural space. METHODS: Patients in group 1 (n = 30) received isobaric 9.75 mg bupivacaine and in group 2 (n = 30) hyperbaric 9.75 mg bupivacaine injected into the subarachnoid space in a combined spinal-epidural technique. They were undergoing urological, gynecological, orthopedic, gastro-intestinal or vascular surgery. Using a double blind technique, the followings parameters were measured: cutaneous analgesia to pinprick, motor blockade, time for two segment regression, time for complete regression of the motor block, quality of anesthesia. In 12 patients the effect of epidural injections of 3 ml lidocaine 2% was observed. RESULTS: Motor and sensory block developed more rapidly (five minutes) in the isobaric group (P<0.05). Maximum upper level (T7+/-2), two-segment regression (52 min in both groups), motor recovery (160 vs. 157 min), and quality of anesthesia did not differ between the two groups. Thirty nine epidural injections of 3 ml lidocaine 2% were given in 12 patients 10 min after spinal injection, 28 were in the hyperbaric group (P<0.05). Twenty six of the epidural injections produced an increase in sensory block of 0 or 1 dermatome, and 13, of 2 or more. CONCLUSION: The block developed more rapidly in the isobaric group, but both isobaric and hyperbaric 9.75 mg bupivacaine produced adequate upper levels of analgesia for surgery. The effect of epidural injections of 3 ml lidocaine 2% was usually minimal.

Adult↗
PubMed1998

Rocuronium is the best non-depolarizing relaxant to prevent succinylcholine fasciculations and myalgia.

PURPOSE: To determine which non-depolarizing relaxant among d-tubocurarine, vecuronium, atracurium, mivacurium and rocuronium prevented muscular fasciculations and myalgia following succinylcholine. METHODS: In this double blind randomized study, 120 female patients scheduled for laparoscopic procedures were studied. They were divided into six groups of 20 according to the non-depolarizing pretreatment used: NaCl 0.9% (control), 0.05 mg.kg-1 d-tubocurarine, 0.01 mg.kg-1 vecuronium, 0.05 mg.kg-1 atracurium, 0.02 mg.kg-1 mivacurium and 0.06 mg.kg-1 rocuronium. Four minutes after the pretreatment, 1.5 mg.kg-1 succinylcholine was injected. Side effects of the pretreatment, the presence and magnitude of fasciculations, the ease of tracheal intubation, myalgia 1, 24 and 48 hr after surgery were observed. A Puritan Bennett Datex 221 NMT Relaxograph monitor was used to evaluate the neuromuscular block. RESULTS: Muscle fasciculations were observed in 19 of the 20 patients in the control group and in 3 of the 20 patients in the rocuronium group, the best of the pretreatments in that aspect. Four patients in the mivacurium group were unable to sustain more than four seconds head-lift after pretreatment (P < 0.05). Tracheal intubation conditions were better and the onset of block was faster and longer after succinylcholine in the control group (P < 0.05). Myalgias were present in 71% of the patients 24 hr postoperatively and the frequency was not different among the groups. CONCLUSION: Among the pretreatments tested, 0.06 mg.kg-1 rocuronium was the best to prevent muscular fasciculations following succinylcholine injection. In the population studied, pretreatment did not prevent postoperative myalgia. Succinylcholine 1.5 mg.kg-1 was more effective without a non-depolarizing pretreatment.

Adult↗
PubMed1997

[Effects of CO2 and adrenaline on 1% lidocaine in axillary block].

OBJECTIVES: To compare lidocaine hydrocarbonate and lidocaine hydrochloride, with and without adrenaline, in the axillary block obtained with a neurostimulator. STUDY DESIGN: Prospective, randomized, double blind study. PATIENTS: Sixty-six patients undergoing surgery of the upper limb under axillary block, allocated into four groups. METHODS: The criteria for evaluation were: onset time, duration and quality of sensory and motor blockades, and blood concentrations of lidocaine in 39 patients. In all patients musculocutaneous, radial, median and ulnar nerves were stimulated and the volume of local anaesthetic administered was 25 mL per square meter of body surface. Group 1 received lidocaine hydrocarbonate 1% (n = 17), group 2, lidocaine hydrocarbonate 1% with adrenaline 1/200,000 (n = 17), group 3, lidocaine hydrochloride 1% (n = 16) and group 4, lidocaine hydrochloride 1% with adrenaline 1/200,000 (n = 16). RESULTS: No significant inter-group differences were found concerning sensory and motor blockades and onset time. The duration of analgesia was longer in groups CO2 + A and HCL + A. The lidocaine blood concentrations were globally lower in group HCL + A. CONCLUSIONS: Considering the cost/benefit ratio and the absence of clinical benefits of lidocaine hydrocarbonate, lidocaine hydrochloride should be preferred.

Adult↗
PubMed1996

Neuromuscular monitoring: does it make a difference?

PURPOSE: The objective of the present prospective study was to evaluate the influence of neuromuscular monitoring on the level of neuromuscular blockade from induction of anaesthesia until extubation of the trachea. METHODS: Forty-two patients aged between 18 and 73 yr undergoing a range of surgical procedures under general anaesthesia were randomly distributed into two groups of 21 patients each. In both groups a Datex NMT Monitor was used and electromyographic responses of the ulnar muscles to supramaximal stimulation of the ulnar nerve were recorded. In Group 1, the anaesthetist could see the movements of the stimulated hand, but not the monitor. In Group 2, the anaesthetist could see neither the stimulated hand nor the monitor. The same anaesthetist administered the neuromuscular relaxants which were succinylcholine 1.5 mg.kg-1 for tracheal intubation and vecuronium 0.1 mg.kg-1 for neuromuscular relaxation during surgery, followed by 1 to 2 mg maintenance injections. Possible residual curarization was evaluated in the recovery room by head life tests and pulse oximetry. RESULTS: Patients in Group 1 had deeper neuromuscular block throughout surgery, despite the use of a comparable dose of vecuronium (10.1 mg for G1 vs 11.2 mg for G2). The EMG values of T1 and train-of-four values were not different at tracheal intubation or at extubation. No patients presented signs of residual curarization in the recovery room. CONCLUSION: The study demonstrates that with the same amount of vecuronium the neuromuscular relaxation was deeper with the use of a simple neuromuscular monitoring (visual evaluation of the thumb movements). Despite the deeper neuromuscular block in the monitored group, there was no residual curarization in the recovery room.

Adolescent↗
PubMed1994

Duration of decubitus position after epidural blood patch.

Thirty patients presenting with post-dural puncture headache (PDPH) were prospectively studied to determine the influence of the duration of the decubitus position after epidural blood patch on the efficacy of treatment. All patients received 12 ml of autologous blood. They were randomly distributed into three groups of ten patients. Patients in Group 1 were maintained in a decubitus position for 30 min after the epidural injection of autologous blood in the epidural space. Patients in Group 2 were maintained for 60 min in decubitus and patients in Group 3 for 120 min. Post-dural puncture headache was evaluated using a visual analogue scale before the epidural blood patch, at the time of initially adopting a standing position after the blood patch, and 24 hr later. The severity of PDPH in the three groups was reduced at the time of initially adopting a standing position and after 24 hr, in comparison with preblood patch VAS (P < 0.001). Patients in Group 3 presented less severe PDPH than patients in Group 1 at the time of initially standing up and 24 hr later (P < 0.05). We conclude that epidural blood patch was effective in treating PDPH but that the maintenance of a decubitus position for at least one hour and preferably for two hours after the blood patch was more effective than maintenance for 30 min.

Adult↗
PubMed1994

Glibenclamide vs gliclazide in type 2 diabetes of the elderly.

The objective of this study was to compare the effect of two sulphonylureas on the frequency of hypoglycaemic events and glycaemic control in elderly patients with Type 2 diabetes. Twenty-two untreated elderly patients were treated with glibenclamide or gliclazide in a randomized double-blind fashion. Prior to treatment, a biochemical profile, an oral glucose tolerance test, and a 2-h hyperglycaemic glucose clamp (glucose 5.4 mmol l-zs-1 above baseline) were performed. Patients were seen regularly over 6 months to assess glycaemic control and the frequency of hypoglycaemic reactions. Hyperglycaemic clamp studies and oral glucose tolerance tests were repeated at 1 and 6 months. The area under the curve for the oral glucose tolerance test (glibenclamide: 15.5 +/- 0.7; gliclazide: 14.9 +/- 0.8 mmol l-1 (p = NS)) and the haemoglobin A1C (glibenclamide: 7.4 +/- 0.2%; gliclazide: 7.9 +/- 0.5% (p = NS)) were similar at 6 months. Hypoglycaemic reactions were significantly more frequent with glibenclamide than with gliclazide: 17 vs 4 (p < 0.01). Insulin sensitivity index (ml kg-1 min-1 pmol-1 x 100) was increased significantly by glibenclamide but not gliclazide (glibenclamide: 0.284 +/- 0.116 (baseline) vs 0.518 +/- 0.102 (6 months) (p < 0.05), gliclazide: 0.260 +/- 0.048 (baseline) vs 0.358 +/- 0.048 (6 months) (p = NS)). We conclude that glycaemic control was equivalent with the two drugs but the incidence of hypoglycaemic reactions was significantly greater with glibenclamide probably because this drug increases insulin sensitivity to a greater degree.

Aged↗
PubMed1993

[Axillary plexus block by simultaneous blockade of several nerves. I. Influence of the volume of the anesthetic solution].

The influence of the volume of local anaesthetic solution on axillary blockade was investigated in a prospective randomized double-blind study including 120 patients presenting for upper limb surgery. A peripheral nerve stimulator was used to carry out the axillary block with a multiple injection technique. The musculocutaneous, radial, median and ulnar nerves were routinely stimulated. Four criteria were monitored: quality of sensory blockade, degree of motor blockade, time of onset and duration of anaesthesia. The patients were randomly allocated into two groups (n = 60 each). In the first, patients received 25 ml per m2 of body surface area of carbonated 1% lignocaine, 0.25% bupivacaine or a 1 to 1 mixture of both. Patients in the other group were given the same amount of local anaesthetic in half the volume, i.e. 12.5 ml.m-2 of carbonated 2% lignocaine, 0.5% bupivacaine or a 1 to 1 mixture of both these. Adrenaline (1 in 400,000) was added to half the anaesthetic solutions used in each group. The data demonstrated that, for a same amount of local anaesthetic, the larger volumes provided better quality sensory blockade than the smaller ones (p < 0.03). However, the volume of solution used affected neither the time of onset nor the duration of anaesthesia, nor the degree of motor blockade. It is concluded that, despite the use of a neurostimulator and simultaneous infiltration of several nerve trunks, the volume required to ensure a reliable degree of sensory block with the technique of axillary block is comprised between 40 and 50 ml (25 ml.m-2).

Adult↗
PubMed1993

[Axillary plexus block by simultaneous blockade of several nerves. II. Evaluation of lidocaine-bupivacaine combination].

A mixture of carbonated lignocaine and bupivacaine for axillary blocks was assessed prospectively in a randomized double-blind study including 60 patients scheduled for upper limb surgery. A peripheral nerve stimulator was used to carry out the axillary block with a multiple injection technique. The musculocutaneous, radial, median and ulnar nerves were routinely stimulated. Four criteria were monitored: quality of sensory blockade, degree of motor blockade, time of onset and duration of anaesthesia. The patients were randomly assigned to three groups (n = 20 each). Patients received 25 ml per m2 of body surface area of either carbonated 1% lignocaine (group 1) or 0.25% bupivacaine (group 2) or a 1 to 1 mixture of both (group 3). Adrenaline (1 in 400,000) was added to half the anaesthetic solutions used in each group. The onset of anaesthesia was faster with the mixture (15 +/- 9 min) than will bupivacaine alone (23 +/- 14 min) (p < 0.02). It lasted longer in the mixture group (264 +/- 111 min) than in the lignocaine group (193 +/- 83 min). The longest duration was in the bupivacaine group (476 +/- 276 min) (p < 0.03). Adrenaline only affected significantly the duration of anaesthesia in the lignocaine group (252 min vs 135 min with and without adrenaline, respectively) (p < 0.03). In axillary blocks, the mixture of carbonated lignocaine and bupivacaine has a faster onset of action than bupivacaine alone, and a longer duration of action than lignocaine alone. Both agents provided a quality of sensory and motor blockade similar to that obtained with the mixture.

Adult↗
PubMed1992

Axillary plexus block using a peripheral nerve stimulator: single or multiple injections.

This prospective, randomized, double-blind study was undertaken to evaluate the success rates of axillary brachial plexus block performed with the help of a peripheral nerve stimulator when either one, two or four of the major nerves of the brachial plexus were located. Seventy-five patients undergoing upper limb surgery were randomly allocated to one of the following five groups according to the nerve and number of nerves to be located; G-1: musculo-cutaneous, radial, median and ulnar nerves; G-2: musculo-cutaneous plus one of the other three nerves; G-3: radial nerve; G-4: median nerve; G-5: ulnar nerve. The sensory block was evaluated before surgery and cutaneous anaesthesia was considered to be present when the needles of a Wartenberg Pinwheel were no longer felt in all the dermatomes of the nerves implicated in the surgical site. Otherwise, the block was considered to need completion before surgery. Only one out of the 15 patients in G-1 and G-2 needed completion of their block before surgery whereas seven out of 15 for G-3 and eight out of 15 for G-4 and G-5 needed completion of their block (P less than 0.01). We conclude that when performing an axillary block with the help of a peripheral nerve stimulator, stimulation of the musculo-cutaneous nerve and one other nerve or stimulation of all four major nerves of the brachial plexus gives a higher success rate than stimulation of only one nerve, whether the stimulated nerve is the median, radial or ulnar.

Adult↗
PubMed1991

Haemodynamic interactions of muscle relaxants and sufentanil in coronary artery surgery.

The haemodynamic interactions between sufentanil (S) and muscle relaxants (MR) were studied in 40 ASA physical status III or IV patients (four groups of ten) scheduled for coronary artery bypass grafting (ABG). Group I received pancuronium (P) 0.08 mg.kg-1, Group II received vecuronium (V) 0.1 mg.kg-1, Group III received atracurium (A) 0.5 mg.kg-1 and Group IV metocurine 0.1 mg.kg-1 plus pancuronium 0.02 mg.kg-1 (M-P). Sufentanil, 20 micrograms.kg-1 was administered before sternotomy, 10 micrograms.kg-1 being injected before tracheal intubation and 10 micrograms.kg-1 afterwards. Heart rate (HR), ECG leadII and V5, systolic, diastolic and mean arterial and pulmonary blood pressures, central venous pressure (CVP) and pulmonary capillary wedge pressure (W) were measured and recorded at the time of seven strategic events between the pre-induction of anaesthesia period and sternotomy. Cardiac output (CO) and systemic vascular resistances (SVR) were also measured before induction of anaesthesia and after the administration of S 10 micrograms.kg-1 plus the MR. The HR decreased from baseline values in the post-tracheal intubation period in all groups except in P group. The mean arterial pressure also decreased significantly in all groups except in the P group. The CO did not change from baseline values but SVR decreased in all groups. There was no evidence of new myocardial ischaemia according to the ECG monitoring and there was no significant difference in the HR changes between patients who had or who had not received beta-blockers in any group. We conclude that within the present study conditions and design, HR and blood pressure changed least with pancuronium.

Adrenergic beta-Antagonists↗
PubMed1990

Clinical, electrical and mechanical correlations during recovery from neuromuscular blockade with vecuronium.

In order to determine correlations between electromyographic (EMG), mecanomyographic (MMG) and clinical criteria of adequate recovery from neuromuscular blockade with vecuronium, seven young healthy conscious volunteers were given subparalysing doses of vecuronium. During recovery from neuromuscular blockade, vital capacity, negative inspiratory pressure, peak expiratory flow rate and five-second head lift were assessed. Neuromuscular monitoring included the evoked EMG response of the adductor digiti minimi and the simultaneous evoked MMG response of the adductor pollicis on the same side. We found that all subjects maintained head lift for five seconds at EMG T4T1 of 0.70, and they achieved normal respiratory tests at EMG T4/T1 of 0.90. The MMG T4/T1 needed for the subjects to perform normal respiratory tests was found to be 0.50, at which time six of the seven subjects were able to perform adequately the head lift test.

Adult↗
PubMed1990

Clinical assessment of the muscular response to tetanic nerve stimulation.

The study was undertaken in order to determine clinical tactile evaluation of tetanic nerve stimulation (50 Hz, 5 sec) as a means of detecting fade and possible residual curarization. Forty-four patients were studied and 128 clinical evaluations by eight different observers were performed at various levels of neuromuscular blockade. Tetanic fade was detected reliably by clinical evaluation only when high degrees of fade (tetanic fade ratio of 0.3 or less) were detected with a force-displacement transducer. We conclude that the clinical tactile assessment of the response to tetanic stimulation is not accurate except at very high degrees of fade and that its usefulness in monitoring neuromuscular recovery is doubtful.

Adult↗
PubMed1989

Atracurium and vecuronium interaction with gentamicin and tobramycin.

Drug interactions between the aminoglycosides (tobramycin and gentamicin) and atracurium and vecuronium were studied prospectively in 44 patients. Twenty-two patients had therapeutic serum levels of tobramycin or gentamicin and 22 served as controls. Onset time, clinical duration, and time to spontaneous recovery of T4/T1 ratio of 0.70 after atracurium or vecuronium injection were measured. No statistically significant differences were found in onset time, but clinical duration and time to recovery were significantly longer in patients receiving tobramycin or gentamicin and paralyzed with vecuronium than for controls (P less than 0.01 for clinical duration and P less than 0.0005 for recovery). The neuromuscular block produced by atracurium was not significantly influenced by the presence of therapeutic serum levels of tobramycin or gentamicin. We conclude that for patients treated with these antibiotics, atracurium may present some advantages over vecuronium when a prolonged block is not desired.

Adult↗
PubMed1989

Hemolysis during cardiopulmonary bypass.

Hemolysis of red blood cells is a problem during cardiopulmonary bypass. The present study was undertaken to evaluate the influence of the priming solution and of the initial acceleration of the pump on red blood cell trauma and hemolysis. Eighty adult patients undergoing coronary artery grafting with cardiopulmonary bypass (CPB) were randomly assigned to one of four groups according to the nature of the priming solution and the initial speed of CPB flow (time from the start to the full calculated flow): group 1, lactated Ringer's (LR) with 5% dextrose (5%D), 1 minute; group 2, LR5%D, 2 minutes; group 3, LR, 1 minute; group 4, LR, 2 minutes. Plasma hemoglobin was found to be 4 times higher in group 1 than in the three other groups (P less than 0.001). It is concluded that there is an interaction between the presence of glucose in the priming solution and the initial acceleration of pump flow. The combination of LR5%D prime with a short time interval to full pump flow leads to a significant degree of hemolysis.

Adult↗