[Docetaxel-induced acute pulmonary capillary-leak syndrome mimicking cardiogenic oedema].
Explore the source record for details and available documents.
Acute Disease↗
Biomedical subjects
G Dhonneur
Publications and source records attributed to G Dhonneur.
Tracheal intubation of morbidly obese patients: LMA CTrach vs direct laryngoscopy.
BACKGROUND: LMA CTrach (CT), a modified version of the intubating LMA Fastrach, allows continuous video-endoscopy of the tracheal intubation procedure. We tested the hypothesis that the CT is efficient for tracheal intubation of morbidly obese patients who are at risk of a difficult airway. METHODS: After Ethics' Committee approval, 104 morbidly obese patients (BMI >35 kg m(-2)) scheduled for bariatric surgery were included in this prospective study. Patients were randomly assigned in two groups: tracheal intubation using direct laryngoscopy (DL) or the CT. Induction of anaesthesia was standardized using sufentanil, propofol and succinylcholine. Characteristics and consequences of airway management were evaluated. RESULTS: Preoperative characteristics of patients and consequences of anaesthesia induction on physiological variables were similar in both groups. Difficulty in facemask ventilation was similar in both groups. Tracheal intubation was successfully carried out with DL and CT. Forty-nine per cent of the patients from the CT group required laryngeal mask manipulation (ventilation and view optimization) resulting in increased duration of tracheal intubation by 57 s as compared with DL. Oxygenation was of better quality in the patients managed with CT than with DL. Blind tracheal intubation was mandatory in eight (17%) patients of the DL group, while tracheal intubation was seen in all patients of the CT group. CONCLUSION: We demonstrated that the CT was an efficient airway device for ventilation and tracheal intubation in case of a difficult airway in morbidly obese patients.
Adolescent↗
Carvedilol inhibits right ventricular hypertrophy induced by chronic hypobaric hypoxia.
Right ventricular hypertrophy induced by chronic hypoxia is mainly due to a mechanical stress upon the ventricular wall secondary to pulmonary arterial hypertension. However, the hypoxic chronic activation of the sympathetic nervous system can contribute to the development of right ventricular hypertrophy either via myocardial adrenergic receptors and/or a vasoconstriction and remodeling of pulmonary arteries. To highlight the specific role of the sympathetic nervous system on hypoxia-induced right ventricular hypertrophy and particularly the efficiency of carvedilol, our study compared physiological, myocardial, and pulmonary arterial morphometric data in rats treated by alpha-(prazosin), or beta-(propranolol) or alphabeta-(carvedilol) antagonist and exposed to chronic hypobaric hypoxia (2 weeks at 380 mmHg barometric pressure). In chronic hypoxia, both systolic right ventricular pressure and Fulton's ratio (right/(left+septum) ventricular weight) were lower in rats treated by prazosin (-16.7 and -13.6%), propranolol (-28.6 and -12.7%) and carvedilol (-15.9 and -14.3%) respectively when compared to glucose (p<0.05). Surprisingly, prazosin was unable to reduce right ventricular hypertrophy induced by chronic hypoxia, whereas, left ventricular weight increased. Wall thickness index of pulmonary arteries increased in chronic hypoxia and was reduced by carvedilol. In conclusion, the hypoxia-induced activation of the adrenergic system participates in the development of right ventricular hypertrophy. Carvedilol is effective in reducing hypoxia-induced right ventricular hypertrophy, pulmonary arterial hypertension, and muscularization of pulmonary arteries.
Animals↗
[rFVIIa administration in patient with a left ventricular assistance patient].
We report the case of a left ventricular mechanical assistance (Incor Berlinheart) in a woman that experienced a postoperative non-surgical haemorrhagic complication following a reconstructive pedicled omentoplasty for implanted materials infection. After massive substitutive therapy failure at reducing blood loss and because of an hypovolaemic shock, high dosage (70 microg/kg twice) of recombinant activated factor VII (r-VIIa) was administrated resulting in spectacular cessation of bleeding and haemodynamic restoration. Continuous repeated clinical evaluation, cardiac echography and electronic monitoring of the axial pump device characteristic did not reveal any thromboembolic accident. This observation brings some indirect arguments for safe rFVIIa treatment in this type of pathology with a high thromboembolic risk.
Aged↗
[Efficiency of secondary posterior trunk single stimulation, low volume infraclavicular plexus block for upper limb surgery].
OBJECTIVES: To assess the efficiency of a posterior secondary trunk single stimulation, low volume (30 ml 1.5% mepivacaine) infraclavicular brachial plexus block (ICB) technique. STUDY DESIGN: Prospective study. PATIENTS AND METHODS: One hundred consecutive patients scheduled for hand, forearm or elbow surgery were included. ICB was placed using a single stimulation technique. 30 ml 1.5% mepivacaine was injected when an evoked distal radial motor type response was elicited for 0.3-0.6 mA intensity current. Based upon both sensory and motor distribution ICB, characteristics and performance were assessed. RESULTS: No patient required general anesthesia conversion. Success rate was 92%. 8 patients required a total amount of 10 complementary distal troncular blocks. No specific complication of ICB technique was accoutered. All patients completed full neurological recovery from ICB 24 hours after surgery. CONCLUSION: 30 ml mepivacaine 1.5% ICB is suitable for upper limb surgery.
Adult↗
Effect of metoclopramide on mivacurium-induced neuromuscular block.
In order to investigate the effect of metoclopramide on the duration of action of mivacurium, 45 patients were randomized into three groups. Group M10 (n = 15) and M20 (n = 15) received 10 and 20 mg of metoclopramide i.v., respectively, and group S (n = 15) received saline 2 min before induction of anesthesia with fentanyl, thiopental and mivacurium. Plasma cholinesterase activity (pCHE) was measured before induction of anesthesia and 2 min after injection of metoclopramide and saline. Neuromuscular block was monitored by a force transducer using train of four nerve stimulation. Anesthesia was maintained with isoflurane and N2O. Time to recovery of a twitch height of 90% was significantly prolonged in group M10 and M20 (44 +/- 15 and 57 +/- 10 min) as compared to group S, 32 +/- 9 min, P < 0.05). A slight but significant decrease in pCHE was observed in group M20. Because of the risk of prolonged duration of action of mivacurium, neuromuscular blockade should always be monitored whenever metoclopramide is given before injection of mivacurium.
Adult↗
Pulmonary scintigraphy for diagnosis of aspiration during intravenous propofol anaesthesia for colonoscopy.
A specific technique for detection of pulmonary aspiration during the perioperative period is lacking. In this study, we developed a scintigraphic method for its diagnosis. Technetium 99m sulphur colloid was given orally 2 h before an i.v. infusion of propofol in patients undergoing elective colonoscopy. During the procedure, patients were spontaneously breathing 100% oxygen via a face mask. After recovery from anaesthesia, patients had a chest scinti-scan. As a control group, 10 healthy men were studied. The lung scan was considered positive if any tracer activity greater than background level was detected in the lung field. Among 96 patients studied, three patients had a positive chest scinti-scan. One of the three patients developed pneumonia while the other two remained asymptomatic. In none of the control asymptomatic group was tracer detected in the chest. We suggest that this technique is specific and can be used as a tool to assess the risk of pulmonary aspiration during different anaesthetic procedures.
Adult↗
The pharmacokinetics of cisatracurium in patients with acute respiratory distress syndrome.
UNLABELLED: Continuous neuromuscular blockade is often necessary in patients being treated for acute respiratory distress syndrome (ARDS) to optimize oxygenation. In this study, neuromuscular blockade (no response to two responses at the train-of-four stimulation at the orbicularis oculi muscle) was achieved in six patients with ARDS by a continuous infusion of cisatracurium. The plasma concentration of cisatracurium during the infusion averaged 1.00 (0.25-1.45) microg/mL, expressed as median (range). The clearance and half-life were 6.5 (3.3-7.6) mL. min(-1). kg(-1) and 25 (16-48) min, respectively. The laudanosine plasma concentrations were 0.70 (0.12-1.20) microg/mL. The pharmacokinetic variables of cisatracurium are similar to those of patients without organ failure undergoing elective surgery. Plasma laudanosine levels always remained well less that those associated with seizure activity in animal models. Long-term infusion of cisatracurium was not associated with any side effects. Cisatracurium is a suitable muscle relaxant when deep and continuous levels of muscle relaxation are required in patients treated for ARDS. IMPLICATIONS: We studied the pharmacokinetics of cisatracurium in six patients treated for respiratory distress syndrome by continuous muscle relaxation. A deep degree of neuromuscular blockade corresponding to abolition of two responses at the orbicularis oculi to train-of-four stimulation was obtained in all patients. The pharmacokinetic variables observed in these severely ill patients were similar to those of anesthetized patients. No accumulation of laudanosine was seen. Cisatracurium appears to be suitable when continuous muscle relaxation is required in critically ill patients.
Adult↗
Intracuff pressure and tracheal morbidity: influence of filling with saline during nitrous oxide anesthesia.
BACKGROUND: Diffusion of nitrous oxide into the cuff of the endotracheal tube results in an increase in cuff pressure. Excessive endotracheal tube cuff pressure may impair tracheal mucosal perfusion and cause tracheal damage and sore throat. Filling the cuff of the endotracheal tube with saline instead of air prevents the increase in cuff pressure due to nitrous oxide diffusion. This method was used to test whether tracheal morbidity is related to excess in tracheal cuff pressure during balanced anesthesia. METHODS: Fifty patients with American Society of Anesthesiologists physical status I or II were randomly allocated to two groups with endotracheal tube cuffs initially inflated to 20-30 cm H(2)O with either air (group A) or saline (group S). Anesthesia was maintained with isoflurane and nitrous oxide. At the time of extubation, a fiberoptic examination of the trachea was performed by an independent observer, and abnormalities of tracheal mucosa at the level of the cuff contact area were scored. Patients assessed their symptoms (sore throat, dysphagia, and hoarseness) at the time of discharge from the postanesthesia care unit and 24 h after extubation on a 101-point numerical rating scale. RESULTS: Cuff pressure increased gradually during anesthesia in group A but remained stable in group S. The incidence of sore throat was greater in group A than in group S in the postanesthesia care unit (76 vs. 20%) and 24 h after extubation (42 vs. 12%; P < 0.05). Tracheal lesions at time of extubation were seen in all patients of group A and in eight patients (32%) of group S (P < 0.05). CONCLUSION: Excess in endotracheal tube cuff pressure during balanced anesthesia due to nitrous oxide diffusion into this closed gas space causes sore throat that is related to tracheal mucosal erosion.
Anesthetics, Inhalation↗
Differential sensitivity of abdominal muscles and the diaphragm to mivacurium: an electromyographic study.
BACKGROUND: Respiratory muscles are considered to be more resistant to muscle relaxants as compared with peripheral muscles. However, the relative sensitivity of respiratory muscles participating to the pump function has not been compared. We used electromyography to compare pharmacodynamic parameters of the diaphragm and abdominal muscles after mivacurium. METHODS: Forty adults undergoing elective surgery were randomly allocated in five dosing groups of mivacurium (50, 100, 150, 200, and 250 microg/kg). Patients anesthetized with propofol and fentanyl underwent intubation without relaxants. Anesthesia was maintained with nitrous oxide and propofol. The right phrenic nerve, the left 10th intercostal nerve, and the ulnar nerve were stimulated. Electromyography of the diaphragm and abdominal muscles was recorded from surface electrodes. Mechanomyography was used to measure adductor pollicis evoked contraction. After a 5-min stable recording period, patients received a single intravenous bolus (20 s) dose of mivacurium. By using log dose-probit effect regression analysis, dose-response curves were constructed. Effective doses and 95% confidence intervals were derived for the diaphragm and abdominal muscles and were compared. RESULTS: The dose-response regression line of abdominal muscles differed from that of the diaphragm. Calculated ED50 and ED90 were higher for the diaphragm than for the abdominal muscles (104 [82-127] and 196 [177-213] microg/kg, and 67 [51-82] and 161 [143-181] microg/kg, respectively). The onset of block was faster and recovery of control responses were shorter at the diaphragm than at the abdominal muscles. CONCLUSION: Diaphragm and abdominal muscles have differential sensitivity to mivacurium. The diaphragm is more resistant to mivacurium than abdominal muscles are.
Abdomen↗
[Sensitivity to atracurium in the lateral abdominal muscles] .
OBJECTIVE: To study the effect of atracurium on the electromyographic activity of the lateral abdominal muscles and adductor pollicis in anaesthetized subjects. STUDY DESIGN: Prospective, comparative, open study. PATIENTS AND METHODS: Sixteen patients, ASA physical status 1 or 2, undergoing elective orthopaedic surgery under general anaesthesia were studied. Anaesthesia was induced with propofol/fentanyl and orotracheal intubation performed after glottic local anaesthesia without using muscle relaxant. Anaesthesia was maintained with isoflurane/nitrous oxide/oxygen and fentanyl reinjections. Supramaximal percutaneous stimulations in a simple twitch mode (0.1 Hz) were applied at the 9th-10th intercostal nerve on the posterior axillary line and at the ulnar nerve at the wrist. The electromyographic responses were registered using skin surface electrodes, placed on the D9-D10 dermatome in regard of the lateral abdominal muscles and of the thenar muscles. After a single bolus dose of atracurium 0.5 mg.kg-1, the following parameters were studied: the maximum effect (Emax), the time for obtaining Emax (Delay) and the recovery time of 5, 10, 25, 50, 75 and 100% of the control neuromuscular response (T5, T10, T25, T50, T75, T100). RESULTS: The dose of 0.5 mg.kg-1 of atracurium induced 100% block in both lateral abdominal muscles and adductor pollicis. Lateral abdominal muscles blockade had faster onset (136 +/- 4 s versus 205 +/- 29 s) and shorter recovery, T5, T10, T25, T50, T75 and T100 were significantly (p < 0.05) shorter than at the adductor pollicis. CONCLUSION: Lateral abdominal muscles blockade have faster onset and recovery than adductor pollicis.
Abdominal Muscles↗
The effects of residual pain on oxygenation and breathing pattern during morphine analgesia.
UNLABELLED: To determine the influence of pain on opioid-induced respiratory depression, we studied oxygenation and breathing patterns in 40 patients scheduled for knee surgery during postoperative patient-controlled analgesia (PCA). After 1 h of morphine PCA, patients were randomized to receive either 20 mL of placebo or bupivacaine 0.25% through a crural nerve catheter and allowed to use PCA for one more hour. Abnormal breathing events were identified and characterized by using the Edentrace II device (Nellcor, Jouy-en-Josas, France). The Spo2 below which the patient spent 25% and 50% of a studied period was calculated (Spo2(25), Spo2(50)). Pain relief with regional analgesia increased the incidence of abnormal respiratory events associated with oxygen desaturation: during the second period, the pain score was lower in the bupivacaine group (0.7+/-1 vs 4.1+/-1.2), morphine consumption was larger in the placebo group (4.2+/-1.3 vs 0.7+/-1.4 mg), and there were more abnormal obstructive breathing events in the bupivacaine group (11+/-16 vs 3.7+/-4.3). Spo2(25) and Spo2(50) were lower in the bupivacaine than in placebo group (91.5%+/-2.8% vs 93.1%+/-2.1%, 92.9%+/-2.4% vs 94.2%+/-1.8%). IMPLICATIONS: Pain relief with regional analgesia in patients previously treated with opioids increases the incidence of abnormal respiratory events associated with oxygen desaturation.
Analgesia, Patient-Controlled↗
Postoperative obstructive apnea.
UNLABELLED: We studied electromyography (EMG) of the geniohyoid muscle (Gh) and diaphragm (Di) in 12 postoperative, premedicated (flunitrazepam 2 mg PO), asymptomatic patients who snored after recovering from general anesthesia, the induction of which was partly achieved by i.v. midazolam. After extubation of the trachea, integrated EMG activity of Gh (E-Gh(MTA)) and Di (E-Di(MTA)) were measured. For Gh, tonic and phasic activity were distinguished. Patients were studied during obstructive apnea, at the end of apnea, while breathing through an artificial Guedel airway, and during quiet breathing 5 min after flumazemil. All patients experienced episodes of postoperative upper airway obstruction and nine became apneic. Flumazenil restored consciousness and predominant tonic E-GhMTA associated with upper airway patency in all patients. Reduced tonic E-GhMTA characterized postoperative obstructive apnea. Resolution of apnea required a burst of both tonic and phasic E-GhMTA associated with intense E-Di(MTA). Breathing through the Guedal airway resulted in patent airway in 8 of 10 patients and was associated with low tonic and phasic E-GhMTA and reduced E-Di(MTA). In this study, we demonstrated that the tonic pharyngeal muscular support modulates airway patency in the postoperative period. Because it is reversed by flumazemil, benzodiazepines are certainly the main cause of airway obstruction in these patients. IMPLICATIONS: Upper airway obstruction during recovery from general anesthesia induced by i.v. midazolam is associated with low tonic pharyngeal muscular support, which modulates upper airway patency in the postoperative period.
Adult↗
A comparison of two techniques for cervical plexus blockade: evaluation of efficacy and systemic toxicity.
UNLABELLED: We compared two techniques of cervical plexus blockade (CPB) for carotid endarterectomy. Cervical plexus nerve block was performed with a combination of bupivacaine and lidocaine, with injections at the C2-C3, C3-C4, and C4-C5 transverse processes in 11 patients (classical CPB) or with a single injection after localization of the cervical plexus with a nerve stimulator in 12 patients (interscalene CPB). Pain scores were obtained during block placement and at predetermined phases of the operation. Arterial blood was sampled before and 3, 5, 8, 10, 15, 25, 40, and 60 min after CPB for measurement of bupivacaine and lidocaine concentrations. Interscalene CPB was less painful than classical CPB. The techniques appeared equally effective. Patients in both groups required equivalent supplementation with IV fentanyl and additional local infiltration with lidocaine during the most painful stages of surgery. The maximal concentration of bupivacaine was lower in interscalene CPB compared with classical CPB (1.0 microg/mL versus 1.5 microg/mL, P < 0.01). The time required to reach the maximal concentration of bupivacaine was 15 (10-40) min in interscalene CPB and 10 (5-17) min in classical CPB (P < 0.05). Lidocaine maximal concentration was similar in both groups, however the time required to reach the maximal concentration was longer (P < 0.05) in interscalene CPB (15 [10-60] min) than in classical CPB (10 [8-20] min). We conclude that the interscalene CPB is as effective as the classical CPB as a regional technique for carotid endarterectomy and may be associated with a lower systemic absorption of bupivacaine. IMPLICATIONS: Cervical plexus blockade for carotid endarterectomy can be effectively performed with a single injection after localization of the cervical plexus with a nerve stimulator. This technique is simple and was associated with less systemic absorption of local anesthetic than the multiple-injection technique.
Aged↗
Effects of an intubating dose of succinylcholine and rocuronium on the larynx and diaphragm: an electromyographic study in humans.
BACKGROUND: Paralysis of the vocal cords is one objective of using relaxants to facilitate tracheal intubation. This study compares the neuromuscular blocking effect of succinylcholine and rocuronium on the larynx, the diaphragm, and the adductor pollicis muscle. METHODS: Electromyographic response was used to compare the neuromuscular blocking effect of succinylcholine and rocuronium on the laryngeal adductor muscles, the diaphragm, and the adductor pollicis muscle. Sixteen patients undergoing elective surgery were anesthetized with propofol and fentanyl, and their tracheas were intubated without neuromuscular blocking agents. The recurrent laryngeal and phrenic nerves were stimulated at the neck. The electromyographic response was recorded from electrodes placed on the endotracheal tube and intercostally before and after administration of 1 mg/kg succinylcholine or 0.6 mg/kg rocuronium. RESULTS: The maximum effect was greater at the adductor pollicis (100 and 99%) than at the larynx (96 and 97%) and the diaphragm (94 and 96%) after administration of succinylcholine and rocuronium, respectively (P < or = 0.05). Onset time was not different between the larynx (58+/-10 s), the diaphragm (57+/-8 s), and the adductor pollicis (54+/-13 s), after succinylcholine (all mean +/- SD). After rocuronium, onset time was 124+/-39 s at the larynx, 130+/-44 s at the diaphragm, and 115+/-21 s at the adductor pollicis. After succinylcholine administration, time to 90% recovery was 8.3+/-3.2, 7.2+/-3.5, and 9.1+/-3.0 min at the larynx, the diaphragm, and the adductor pollicis, respectively. Time to 90% recovery after rocuronium administration was 34.9+/-7.6, 30.4+/-4.2, and 49.1+/-11.4 min at the larynx, the diaphragm, and the adductor pollicis, respectively. CONCLUSION: Neuromuscular blocking effect of muscle relaxants on the larynx can be measured noninvasively by electromyography. Although the larynx appears to be resistant to muscle relaxants, we could not demonstrate that its onset time differed from that of peripheral muscles.
Adult↗
Is the recovery profile of mivacurium independent of the rate of decay of its plasma concentration in patients with normal plasma cholinesterase activity?
BACKGROUND: The duration of action of muscle relaxants is poorly correlated to the rate of decay of their plasma concentration. The plasma concentration of mivacurium may rapidly decrease below its active concentration because of the extensive hydrolysis of mivacurium. By inflating a tourniquet on one upper limb for 3 min after the administration of atracurium, mivacurium or vecuronium, we studied the influence of the initial decline of their plasma concentration on their effect. METHODS: In 50 patients anaesthetised with thiopental, isoflurane and fentanyl, the effect of bolus doses of 0.15 or 0.25 mg.kg-1 mivacurium (MIV 15, MIV 25), 0.3 or 0.5 mg.kg-1 atracurium (ATR 30, ATR 50) and 0.06 or 0.1 mg.kg-1 vecuronium (VEC 06, VEC 10) were measured on both arms (evoked response of the adductor pollicis to train-of-four stimulation every 12 s), a tourniquet being applied on one arm just before and during 3 min after the muscle relaxant bolus. RESULTS: Tourniquet inflation of 3 min almost abolished the neuromuscular effect of mivacurium. In the vecuronium groups and in the ATR 50 group, tourniquet inflation did not modify the maximum degree of depression of the twitch response. Also, the duration of action of vecuronium was unaffected by the tourniquet. In the ATR 30 group, times to return of the twitch response to 25% (duration 25%) and 75% (duration 75%) of control response were significantly shorter in the cuffed arm, 23 min vs 27 min, and 41 min vs 45 min, respectively. In the ATR 50 group, only duration 25% was significantly shorter in the cuffed arm (41 min vs 45 min). CONCLUSION: The results suggest that the rate of decline of the plasma concentration of mivacurium is so rapid, that a very low and almost clinically ineffective concentration is present as soon as 3 min after its administration. The results also indicate that the recovery from a mivacurium-induced neuromuscular blockade is not influenced by the rate of decay of its plasma concentration in patients with genotypically normal plasma cholinesterase.
Adult↗
Neostigmine reversal of vecuronium neuromuscular block and the influence of renal failure.
The duration of clinical relaxation induced by vecuronium and reversal by neostigmine was studied in 40 patients with renal failure (RF) and 40 patients with normal renal function (NL) under general anesthesia. Patients were premedicated with flunitrazepam, and anesthesia commenced with fentanyl 1-2 micrograms/kg, thiopental 5-8 mg/kg, and vecuronium 0.1 mg/kg. Anesthesia was maintained with 60% nitrous oxide in oxygen, isoflurane 0.3%-1.0% end-tidal concentration, and 1 microgram/kg fentanyl every 20-30 min. Neuromuscular block was reversed by the administration of intravenous neostigmine 40 mg/kg at the time of reappearance of either two or four responses to the train-of-four (TOF) stimulation. Monitoring of neuromuscular function consisted of supramaximal TOF stimulation of the ulnar nerve and the evoked thumb response was registered using a force transducer. Spontaneous recovery time, reversal time, and the time to recovery of TOF ratio to 0.7 were recorded. RF did not prolong the vecuronium neuromuscular blocking effect, reversal was achieved at the same rate in NL as in RF, and the duration of reversal of neuromuscular blocking effect of vecuronium was not influenced by the time of administration of neostigmine. Therefore, the neuromuscular blocking effect of a tracheal intubating dose of vecuronium can be reversed at the same rate in patients with end-stage RF as in patients with normal kidney function.
Adult↗
A comparison of the neuromuscular blocking effects of atracurium, mivacurium, and vecuronium on the adductor pollicis and the orbicularis oculi muscle in humans.
Both the orbicularis oculi (OO) and the adductor pollicis (AP) muscles have been used to indirectly quantify the extent of neuromuscular block of the respiratory muscles. To clarify any differences in response of these muscles to neuromuscular blocking drugs, the effects of two different doses of atracurium, mivacurium, and vecuronium on the AP and OO were studied. A new technique was used to measure the evoked mechanical response of the OO with accelerometry. Fifty premedicated patients were anesthetized with 5-8 mg/kg thiopental and 2 micrograms/kg fentanyl intravenously (i.v.). They were randomly allocated to receive a single dose of either 300 or 500 micrograms/kg atracurium, 150 or 250 micrograms/kg mivacurium, or 60 or 100 micrograms/kg vecuronium i.v. After orotracheal intubation, anesthesia was maintained with nitrous oxide 60% in oxygen, isoflurane 0.5%-1.5% end-tidal, and 1-2 micrograms/kg fentanyl boluses as required. The evoked response of the AP after ulnar nerve stimulation was measured using a force transducer, and that of the OO after facial nerve stimulation was measured with accelerometry using a piezoelectric probe fixed to the eyelid. The following variables were recorded for each muscle: the maximum depression of the first twitch response to the train-of-four (EMAX), the time to achievement of EMAX (TMAX), the time to recovery of the first twitch response to 25%, 50%, 75%, and 90% of control value (TH25, TH50, TH75, and TH90, respectively) and the time to recovery of the train-of-four response to a ratio of 70% (TOF 0.7). The smaller dose of each relaxant was significantly less potent than the larger dose at the OO. TMAX was shorter for the OO than for the AP at the larger dose of each drug. TH 25 was shorter at the OO than at the AP with 0.5 mg/kg atracurium, but there was no significant difference with 0.25 mg/kg atracurium. TH25 and TH50 were both faster at the OO than at the AP with mivacurium, but there was no difference with vecuronium. TOF 0.7 was shorter with the smaller dose of each drug, but there was no difference with the higher doses. It is concluded that it is possible to record the mechanical response of the OO muscle using a noninvasive method. There are differences between the responses of the OO and the AP to neuromuscular blockers that depend upon both the specific drug itself and the dose used.
Adult↗