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The authors reviewed in a retrospective study 61 cases of severely head injury children who where admitted in the rehabilitation centre to evaluate the outcome 1 and 5 years after the brain injury. Neurologic and neuropsychologic status of children was assessed ad admission, 1 and 5 years later. Duration on intubation and age at time of head trauma were the worst functional prognosis. [Copyright &y& Elsevier]

Pain management in paediatric neurosurgery must be a daily concern for surgeons and anaesthetists. Pain assessment in infants and small children is difficult to perform because of limitations associated with these patients. The association of safe and effective analgesics allows good pain relief together with good safety conditions. However, neuropathic pain, which may occur following neurosurgical procedures, will require further studies. [Copyright &y& Elsevier]

Abstract: Variant Creutzfeldt-Jakob disease (vCJD) is the only form of prion diseases linked to bovine spongiform encephalopathy (BSE). The surgical and anaesthetic management in patients having Creutzfeldt-Jakob disease is rare. Maternofoetal and human transmission of Creutzfeldt-Jakob disease is still unknown. The principles for managing these new risks are not described in obstetric recommendations. We report the case of an 18-year-old woman, who developed the variant Creutzfeldt-Jakob disease during her pregnancy. [ABSTRACT FROM AUTHOR]

We report the case of a 76-year-old man who received a spinal anaesthesia for inguinal hernia repair surgery. A cranial CT scan which was performed because the patient complained of postoperative headache and hemiparesis showed an important pneumocephalus. Because postoperative questioning revealed that the patient had a chronic and neglected rhinorrhea, we hypothesise that this pneumocephalus was secondary to an old unknown osteodural leak with intracranial air entry secondary to the spinal anaesthesia-releated decrease in CSF pressure. [Copyright &y& Elsevier]

Background: Pediatric tracheal intubation requires considerable expertise and can represent a challenge to many anesthesiologists. Confirmation of correct tracheal tube position relies on direct visualization or indirect measures, such as auscultation and capnography. These methods have varying sensitivity and specificity, especially in the infant and young child. Ultrasonography is noninvasive and is becoming more readily available to the anesthesiologist. In this study, we investigated the characteristic real-time ultrasonographic findings of the normal pediatric airway during tracheal intubation and its suitability for clinical use., Methods: Thirty healthy children with normal airways requiring tracheal intubation were studied. Ultrasonographic measurements of the pediatric airway during tracheal intubation under deep inhaled anesthesia were performed using a Sonosite Titan (Sonosite, Bothell, WA) scanner while recording characteristic images during this process. Correct tracheal tube placement was further confirmed using auscultation and satisfactory end-tidal capnography., Results: The mean (+/- sd) age of studied patients was 48 +/- 37 mo, weight was 19.7. +/- 8.6 kg and the sex ratio (m/f) was 1:2. Successful tracheal intubation was verified using the following criteria: 1) identification of the trachea and tracheal rings, 2) visualization of vocal cords, 3) widening of glottis as the tracheal tube passes through, and 4) tracheal tube position above carina and demonstration of movement of the chest wall visceroparietal pleural interface (i.e., sliding sign) after manual ventilation of the lungs. One esophageal intubation was readily recognized by visualization of the tube in the left paratracheal space., Conclusion: This study describes characteristic ultrasonographic findings of the pediatric airway during tracheal intubation. It suggests that ultrasonography may be useful for airway management in children.

Malignant hyperthermia (MH) in a pediatric patient during sevoflurane anesthesia with only a minor rise of endtidal CO(2) is described. MH was considered because of increased rectal temperature. The outcome was favorable after the initiation of a few simple measures (increased minute ventilation, cessation of sevoflurane). As recommended by the regional MH Reference Center, dantrolene was not used. In vitro contracture tests were performed on muscle biopsies from both parents. A strong contracture in response to halothane confirmed the father's MH susceptibility, thereby according a high probability of an MH episode in his son.

We designed this multicenter trial to evaluate the performance and safety of the Ambu laryngeal mask, a new disposable supraglottic airway device, in patients scheduled for elective surgery. One-hundred-eighteen nonparalyzed, anesthetized patients (ASA physical status I-II, age, 18-65 yr, body mass index, 18-30 kg/m(-2)) receiving total IV anesthesia were included in this study. After device insertion, fiberoptic position and oropharyngeal leak pressure were determined at an intracuff pressure of 60 cm H2O. Ease of ventilation was determined by controlling ventilation at 6 mL/kg tidal volume. Any complications were noted and recorded. Device placement was successful in all patients on the first or second attempt (92.4% or 7.6%, respectively) with an insertion time (removal of face mask until first tidal volume) of 44.9 +/- 37.91 s. Adequate ventilation was achieved in all patients and the vocal cords could be visualized by fiberoptic endoscopy in 91.5% of patients. Oropharyngeal leak pressures were 24.1 +/- 5.44 cm H2O. Blood was detected on the device in 8.5% of patients. Complications and patient complaints were minor and quickly resolved. The Ambu laryngeal mask is easy and quick to insert and provides a safe and efficient seal during positive pressure ventilation in nonparalyzed patients scheduled for elective surgery.

Malignant hyperthermia susceptibility (MHS) is a subclinical pharmacogenetic disorder caused by an impairment of skeletal muscle calcium homeostasis in response to triggering agents. While in vitro contracture testing (IVCT) is the gold standard for defining MHS, molecular analysis is increasingly used to diagnosis MHS. Mutations associated with MHS have been reported in two genes: RYR1 and CACNA1S. Mutations in RYR1 are also responsible for central core disease (CCD), a myopathy that can be associated with a positive IVCT response. We report here the results of correlation studies performed with molecular, pharmacological, histological, and functional data obtained in 175 families (referred to as confirmed (129) or potential (46) MHS families). Extensive molecular analysis allowed us to identify a variant in 60% of the confirmed MHS families, and resulted in the characterization of 11 new variants in the RYR1 gene. Most mutations clustered to MH1 and MH2 domains of RYR1. Functional analysis allowed us to assign a causative role for seven MHS mutations that we propose to add to the panel of MHS mutations used for genetic testing. The use of genetic data to determine MHS status led to a 99.5% sensitivity for IVCT. IVCT-positive/mutation-negative diagnoses were analyzed not only in terms of specificity for IVCT, but also to assess the presence of a second MHS trait in families, and the genetic heterogeneity of the disease. Histological analyses revealed the presence of cores in more than 20% of muscle biopsies originating from 242 genotyped and tested MHS patients who did not present with clinical symptoms. This indicates that these patients must be considered as MHS patients with cores, and are clearly differentiated from CCD patients who have been tested positive for MHS., (Copyright 2005 Wiley-Liss, Inc.)

Propofol is an intravenous anaesthetic agent, which presents interesting features for its use in neuro-anaesthesia: it is a powerful hypnotic that does not increase the intracranial pressure. The delay of recovery is short even after several hours of continuous infusion. This is essential for a fast neurologic examination. Continuous infusion should be preferred to bolus in order to prevent hypotension and decrease of the cerebral perfusion pressure. Target-controlled infusion models based on effect site concentrations are now available through several softwares. This technique appears especially useful for awake craniotomy and functional neurosurgery. The level of consciousness is easily fixed between deep anaesthesia and light sedation permitting to ask the patient to move following orders. A sedation controlled by the patient himself is even possible.

Hip-flexed postures enlarging the pelvic diameter are used to improve the obstetric course of labour. Although most investigations show that lateral and sitting positions do not affect the spread of epidural analgesia, the effect of recently introduced hip-flexed postures has yet to be confirmed. This prospective randomised study included 93 parturients. Ropivacaine 0.1% 12 mL plus sufentanil 0.5 micrograms/mL was administered epidurally over a period of 6 min in one of four postures: sitting, right hip-flexed left lateral position, left hip-flexed right lateral position and supine 30 degrees lateral tilt as a control group. Left and right cephalad and sacral epidural spread were measured every 2 min over a period of 30 min. Pain relief, motor blockade and maternal and fetal side effects were noted. The total epidural spread was 15+/-0.3 dermatomes and the upper level of thermo-algesic blockade T7-T8 (range T3 to T10) in all groups. There were no differences between groups in left or right total spread or upper level of epidural blockade, time to maximal block or pain relief. There was no motor block nor any maternal or fetal side effects. The power of the study (1 - beta) was 93%. We conclude that, for the three hip-flexed postures tested, position does not influence local anaesthetic spread or symmetry of thermo-algesic blockade after induction of obstetric epidural analgesia.

Background: Thrombotic thrombocytopenic purpura (TTP) is a rare cause of severe thrombocytopenia in pregnancy., Methods: Six pregnancies in five patients with TTP were followed prospectively over 5 years. Ultralarge von Willebrand factor (ULvWF) multimers and cleaving protease (cp) levels were measured., Results: TTP relapsed, complicating four of the six pregnancies. Of three patients who relapsed, two had complete or partial vWF-cleaving protease (vWF-cp) deficiency, and one had a normal vWF-cleaving protease level. In all three we found abnormal UL multimers. The two women who did not relapse had normal vWF-cleaving protease level and an absence or loss of UL multimers., Conclusions: Pregnant patients with a history of TTP must be followed in a tertiary obstetric unit with plasmapheresis available. Influence of vWF-cleaving protease and vWF multimeric abnormalities on TTP relapsing during pregnancy has to be evaluated in a further multicentre study.

Objectives: The use of epidural analgesia and anaesthesia is controversial in patients with multiple sclerosis (MS) due to the potential neurotoxicity of local anaesthetics. The aim of this study was to evaluate the place and the safety of epidural obstetrical analgesia in these patients., Patients and Methods: A consecutive series of 19 patients with MS was studied over 4 years, recording the type of anaesthesia and the obstetric and neurologic observations during the pregnancy and post-partum., Results: Ten patients had epidural analgesia. One patient had a caesarean section under epidural anaesthesia. Five patients relapsed during the post-partum period. Only one of them had an epidural for a spontaneous vaginal delivery, without any evidence of a causal relationship. Spinal anaesthesia is generally not advocated in the presence of MS due to concerns relating to the stronger local anaesthetics required and was therefore not used., Conclusion: The results confirm that epidural analgesia is innocuous in this context. The important points are the precise evaluation of the existing neurological symptoms and the sparing of local anaesthetics thanks to the addition of opioids.

Background: Malignant hyperthermia susceptibility (MHS), an uncommon syndrome often inherited as an autosomal dominant trait, is characterized by a genetic and clinical heterogeneity. In this article, the authors described six pedigrees in which both parents of MHS patients were diagnosed with MHS by an diagnostic test. Haplotype and mutation analysis revealed that more than one MHS genetic trait was present in these families., Methods: A panel of 104 MHS families were investigated with a caffeine halothane contracture test on muscle biopsy specimens. When possible, blood creatine kinase concentrations of MHS patients were measured. Haplotyping studies were conducted with chromosome 19q13.2 polymorphic markers and mutations were searched for in patients' DNA., Results: In six families, the diagnostic test and genetic studies demonstrated that both, apparently unrelated, parents of MHS patients were MHS. In three families, homozygous or compound heterozygous individuals for RYR1 mutations were characterized at a molecular level. In one family, a compound heterozygous patient harboring a RYR1 mutation and a CACNA1S mutation was identified. While patients with two mutated alleles did not show differences in their muscle response to halothane or caffeine, their creatinine kinase concentrations were significantly elevated compared with the heterozygous patients., Conclusions: Based on genetic and diagnostic test data, more than one MHS allele associated with the MHS phenotype was evidenced in four families. These data should be considered in view of the use of genetics for the diagnosis of MHS and when reaching conclusions of genetic heterogeneity in MHS families. Taking into account the usual dominant mode of transmission of MHS and the size of the investigated population, the authors propose an evaluation of the incidence of the MHS in the general population based on genetic data.

Objectives: To determine the incidence of brain death (BD) and to evaluate the registration of potential organ donors (PD) by the organ procurement team (OPT)., Study Design: Two-year prospective audit in the French university hospital of Lille., Patients and Methods: All deaths occurring in the intensive care units or the emergency department were studied. If death was consecutive to brain damage, on-site review of medical records and charts was performed. Death cause, presence of criteria for brain death and reference to the OPT were recorded for each death. A medical expert staff evaluated the incidence of and reasons for unsuitability for organ donation. After 12 months of observation, a protocol for "systematic alert of the OPT when brain death is suspected" was broadcast and evaluated during the next 12 months., Results: During the first period, 277 BD occurred and 119 PD were suitable for organ donation. The OPT recorded 80 PD (67.2% of all PD) and 45 multi-organ procurements (MOP) were performed. Physicians opposed two major reasons for not calling OPT: anticipation of a non-validated medical contraindication in 18 cases and approach of the family without the OPT team in 21 cases. After broadcast of the protocol, 110 PD were identified and the OPT was called in 93 cases (84.5% of all PD, p < 0.004 versus first period). Fifty-three MOP were performed., Conclusion: The OPT was not called to manage one-third of the PD. The protocol for "systematic alert of the OPT when brain death is suspected" improves the call of the OPT and increases MOP.

Objective: To assess whether halothane exposure could influence contraction-relaxation coupling of human skeletal muscle with malignant hyperthermia susceptibility. STUDY DESIGNED: Laboratory investigation., Material and Methods: Muscle biopsies from 14 patients, including six classified as susceptible to MH (MHS) and eight as classified as non-susceptible (MHN) according to criteria of the European MH group. Mechanical parameters of strips were obtained before and after 3 vol% halothane exposure. The contraction and relaxation parameters were measured under isotonic and isometric conditions: maximum shortening and lengthening velocities (respectively maxVc and maxVr); peak of the positive (+dP/dtmax) and negative (-dP/dtmax) twitch tension derivative; ratio R1 = maxVc/maxVr and ratio R2 = (+dP/dtmax) (-dp/dtmax)., Results: In MHN muscle, halothane markedly increased maxVc and maxVr, so that the ratio R1 was unchanged. Both +dP/dtmax and -dP/dtmax increased such that the ratio R2 did not vary. In MHS muscle, halothane induced a significant decrease in maxVr (p < 0.05) without changes in maxVc, so that the ratio R1 increased significantly. +dP/dtmax remained unchanged whereas -dP/dtmax decreased significantly; the ratio R2 increased (p < 0.05)., Conclusion: Our results indicated that, in MHN muscle the contractility property is improved with halothane exposure. In MHS muscle, halothane caused an impairment of relaxation. The mechanical abnormalities observed in this study might be related to sarcoplasmic reticulum dysfunction in MH diseases.

Pain management in paediatric neurosurgery must be a daily concern for surgeons and anaesthetists. Pain assessment in infants and small children is difficult to perform because of limitations associated with these patients. The association of safe and effective analgesics allows good pain relief together with good safety conditions. However, neuropathic pain, which may occur following neurosurgical procedures, will require further studies.

The authors reviewed in a retrospective study 61 cases of severely head injury children who where admitted in the rehabilitation centre to evaluate the outcome 1 and 5 years after the brain injury. Neurologic and neuropsychologic status of children was assessed ad admission, 1 and 5 years later. Duration on intubation and age at time of head trauma were the worst functional prognosis.

Functional neurosurgery procedures are long and specific. Cooperation of the patient may be necessary during surgery. The interference of anaesthetic agents with electrophysiological monitoring should be as little as possible. Local anaesthesia combined with intravenous sedation is often used, but general anaesthesia is more comfortable and secure. Since awakening during the procedure is generally planed, it has to be quick, reliable and of excellent quality. These requirements are fulfilled by the association of propofol by target-controlled infusion (TCI) and a continuous infusion of remifentanil.

Objective: To analyse the current knowledge concerning anaesthetic malignant hyperthermia., Data Sources: References were obtained from computerized bibliographic research (Medline), recent review articles, the library of the service and personal files., Data Synthesis: Knowledge to possess, about the diagnosis and treatment of the acute hyperthermia crises and about "safe-anaesthesia" for malignant hyperthermia susceptible patients, are explained. The pathophysiology chapter give information about the calcium's transport and the defect existing in MH. Molecular genetics of MH find linkage to the region encoding the RyR1. The profile of hyperthermia episodes has changed over time due to the endtidal carbon dioxide-monitoring. Clinical aspects of MH are exposed. The treatment of the acute hyperthermia crises consist mainly to stop all triggering agents instantly and infuse dantrolene sodium. The gold standard for the diagnosis of malignant hyperthermia susceptibility relies on the in vitro contracture test (halothane and caffeine). Associated to genetic studies, it could lead to an non-invasive screening of the MH susceptibility. A protocol for "safe-anaesthesia" is proposed. Some syndromes with features similar to those of MH should be known (central core disease and exertionnal rhabdomyolysis).

A 26-year-old man had proximal weakness in the shoulder and the pelvic girdle since infancy. His sister, aged 16 years, presented a similar phenotype with more pronounced pelvic weakness. His muscle biopsy showed dense non-reducing inclusions which had a lamellar pattern at the ultrastructural level. These structures showed the typical features of fingerprint inclusions which were widely distributed in the fibers. Several central cores and other structural changes such as Z-line streaming were also observed. In view of the central cores, the male patient was investigated for malignant hyperthermia susceptibility. After exposure to halothane or caffeine, unusual intense contractures were observed on fiber preparations. The coexistence of central cores associated with fingerprint inclusions is suggestive of mixed congenital myopathy, which is in our case associated with malignant hyperthermia susceptibility.

Purpose: Use of inhaled nitric oxide (iNO) could be of importance in emergency cases of primary pulmonary hypertension (PPH) in pregnant patients during labour and delivery. iNO acts as a selective pulmonary bed vasodilator avoiding systemic hemodynamic effects due to its ease of administration. Pulmonary bed vasodilation improves right ventricular function directly and left ventricular function indirectly., Clinical Features: We report the case of a pregnant patient with unexpected PPH in whom an emergency Cesarean section (CS) had to be performed. PPH was diagnosed on admission as she arrived in active labour at 34 weeks gestational age. An emergency CS was performed under epidural anesthesia for breech presentation . All along labour, delivery and the first 24 hr, iNO was administered via a noninvasive ventilation device. CS was uneventful. A severe pulmonary hypertensive crisis was observed 12 hr after delivery and resolved with an increase of iNO concentration and administration of isoprenalin. The patient and baby returned home on day ten., Conclusion: The ease of administration of iNO allowed the optimal control of pulmonary arterial hypertension. No interaction with epidural anesthesia was observed. Use of iNO can improve the management of urgent CS in women with unexpected PPH.

We report a case of a patient with carnitine palmityl deficiency in active labour. We discuss the metabolic and energetic implications of obstetrical labour in regard with the mitochondrial myopathy and we propose an optimal management. Neuroaxial analgesia and glucose infusion are indicated in early labour because it is necessary to alleviate stress and pain in order to avoid rhabdomyolysis associated with CPT deficiency. Combined spinal epidural analgesia using intrathecal opioid alone then epidural naropein should be a relevant choice because of a minimal motor blockage. Monitoring of myolysis using serum creatinine phosphokinase levels must take in account CK and MB fractions releases to the circulation during obstetrical labour.

The aim of this investigation was to assess the effect of halothane on the velocity of shortening and lengthening of muscle from normal subjects and from patients with malignant hyperthermia susceptibility. Strips were mounted horizontally at optimal length in normal Krebs-Ringer's solution and mechanical parameters were obtained before and after exposure to 3 vol.% halothane. The maximun shortening velocity at zero load (V(max)) was determined by using Hill's characteristic equation. The contraction and relaxation indices were measured under isotonic and isometric conditions: maximum shortening and lengthening velocities (maxV(c) and maxV(r), respectively); isometric peak twitch tension; peak of the positive (+dP/dt(max)) and negative (-dP/dt(max)) twitch tension derivative; ratio R1=maxV(c)/maxV(r) and ratio R2=(+dP/dt(max))/(-dP/dt(max)). In normal muscle, halothane markedly increased V(max), maxV(c) and peak twitch tension by 30+/-10%, 30+/-5% and 40+/-15%, respectively. The maxV(r) values increased concomitantly with the maxV(c) values, such that no change in the ratio R1 was observed. Both +dP/dt(max) and -dP/dt(max) increased such that the ratio R2 did not vary. In malignant hyperthermia susceptibility muscle, halothane induced a significant decrease in V(max) (-30+/-10%) and maxV(r) (-45+/-15%) without changing maxV(c). The decrease in maxV(r) was greater than that of maxV(c), such that the ratio R1 increased significantly. Peak twitch tension and +dP/dt(max) remained unchanged whereas -dP/dt(max) decreased significantly; the ratio R2 increased by 40+/-10%. These results suggest that halothane alters the contractile properties of malignant hyperthermia susceptibility muscle.

Objective: To assess the reactivity of sarcoplasmic reticulum to caffeine, using the skinned muscle fibre tension test and to compare it with the reference in vitro contracture test in the diagnosis of malignant hyperthermia (HM) susceptibility., Study Design: Laboratory investigation., Material: Muscle biopsies from 63 patients, including 29 classified as susceptible to MH (MHS) and 34 classified as non-susceptible (MHN) according to criteria of the European and the North American MH groups., Method: The reactivity to caffeine and halothane of skinned muscle fibres was compared, according to the type of fibres, with the data of the in vitro contracture test. The type of fibres (type I: oxidative, slow; type II: glycolytic, fast) were determined with strontium dose-response curves., Results: The reactivity to caffeine was significantly lower in the MHS group, for both type I and type II skinned fibres. However, in comparison with the data of the in vitro contracture tests, using the ROC curve analysis, the best sensitivity-specificity compromise was 90%-71% and 74%-84% for type I and type II skinned fibres respectively., Conclusion: The skinned muscle fibre tension test cannot be used instead of the in vitro contracture test for the diagnostic of MHS. However, it may strengthen the data of the latter.

Objective: To compare the analgesic efficiency, side effects and obstetrical repercussions of epidural analgesia (EP) and combined spinal-epidural analgesia (CSE)., Study Design: Prospective, randomized, double or single-blind studies as required, approved by the ethical committee of the institution., Patients: The study included 80 parturients, in active labour with a singleton in vertex presentation and a cervical dilatation of 3 cm or less, randomly allocated to receive either EP (n = 40) or CSE (n = 40)., Method: In the EP group, sufentanil (20 micrograms) and 0.25% bupivacaine (6-8 mL) were injected into the epidural space. In those of the CSE group, sufentanil (10 micrograms) was first injected into the subarachnoid space, followed by an epidural injection of the same agents at the same quantities as for the EP group. Additional analgesia was obtained in both groups by top-ups of 6-8 mL of 0.25% bupivacaine at the request of the patients. Analgesia, course of labour, obstetrical outcome, and neonatal status were assessed. Statistical analysis was performed using Anova, chi 2 analysis, Yates' correction or Fisher's exact test, with a P < 0.05 considered as significant., Results: Both groups had similar demographic and obstetric data. The onset of analgesia was more rapid in CSE group (8 +/- 11 min vs. 12 +/- 7 min, P < 0.05), however the duration was similar. Technical incidents were more frequent in the CSE group (30% vs. 7%, P < 0.05). The technique of analgesia did not influence the bupivacaine amounts required for its maintenance. The incidence of adverse effects were comparable with the exception of vertigo, which was more frequent in the EP group (57% vs. 28%, P < 0.05). The first stage of labour was increased by 30% in the CSE group (281 +/- 130 min vs. 216 +/- 97 min, P < 0.05), without significant prolongation of labour length. Durations of second stage and expulsion were similar in both groups, despite the administration of a lower dose of bupivacaine in the CSE group (33 +/- 17 mg vs. 46 +/- 12 mg, P < 0.05). The rates of instrumental deliveries and Caesarien sections were comparable. The Apgar scores were satisfactory at 5 min., Conclusion: In the early phase of labour, the CSE technique using intrathecal sufentanil has no significant benefit when compared to the EP technique using bupivacaine and sufentanil. In the CSE group, technical incidents were more frequent and the length of the first stage of labour was increased.

Angioneurotic oedema is a rare disease caused by Cl esterase inhibitor deficiency. Hereditary angioneurotic oedema includes type I (quantitative and functional) deficiency and type 11 (functional) deficiency. Its prophylactic treatment during pregnancy, based on danazol therapy if the fetus is male, may avoid acute attacks of generalized or laryngeal oedema. It must be instituted before delivery and carried into the postpartum period. If the fetus is female, epsilon aminocaproic acid may be used. The acquired form of angioneurotic oedema can be due to antibodies to C1 esterase inhibitor. A prophylactic therapy is not well established, but high doses of corticosteroids are recommended. Operative delivery is best avoided when possible. Regional analgesia is indicated for labour or caesarean section to prevent pain and stress and to avoid the difficulties associated with laryngeal oedema and tracheal intubation. In the treatment of an acute attack, Cl esterase inhibitor concentrates (1500 units) may be given i.v. We present two cases, one of hereditary and one of acquired angioneurotic oedema, both presenting during pregnancy and both delivered vaginally under epidural analgesia with successful outcome.

Background: An increase in masseter muscle tone in response to halothane or succinylcholine anesthesia (or both) can be observed in healthy persons. Thus the authors compared the fiber-type halothane and succinylcholine sensitivities in human masseter and vastus lateralis muscles., Methods: Masseter and vastus lateralis muscle segments were obtained from 13 and 9 healthy persons, respectively. After chemical skinning of a single fiber and loading the sarcoplasmic reticulum with Ca++ 0.16 microM solution, halothane (0.5-4 vol% bubbled in the incubating solution), succinylcholine (0.1 microM to 10 mM), or both sensitivities were defined as the concentration inducing more than 10% of the maximum tension obtained by application of 16 microM Ca++ solution. The myofilament response to Ca++ was studied with and without halothane by observing the isometric tension of skinned masseter fibers challenged with increasing concentrations of Ca++. Muscle fiber type was determined by the difference in strontium-induced tension measurements., Results: A significant difference in halothane sensitivity was found between type 1 masseter fibers (0.6+/-0.2 vol%; mean +/- SD) versus type 1 (2.7+/-0.6 vol%) and type 2 vastus lateralis muscle (2.5+/-0.4 vol%). Succinylcholine did not induce Ca++ release by the sarcoplasmic reticulum. In the masseter muscle, 0.75 vol% halothane decreased the maximal activated tension by 40% but did not change the Ca++ concentration that yields 50% of the maximal tension., Conclusions: The very low halothane threshold for Ca++ release from the masseter muscle usually could be counteracted by a direct negative inotropic effect on contractile proteins. However, halothane may increase the sensitivity of the sarcoplasmic reticulum Ca++ release to succinylcholine-induced depolarization, leading to an increase in masseter muscle tone.

The purpose of this investigation was to compare the effects of halothane on malignant hyperthermia (MH) and normal isolated muscle bundle performance during isometric contraction and relaxation phases. Mechanical parameters were measured: peak tension (PT), time to peak tension (TPT) and positive peak of isometric tension derivative (+dP/dtmax) characterized the contraction phase. Half-relaxation time (RT1/2) and negative peak of isometric tension derivative (-dP/dtmax) characterized the relaxation phase. The ratio R = (+dP/dtmax)/(-dP/dtmax) was used to study the coupling between contraction and relaxation under isometric condition. In normal muscle, halothane increased PT by nearly 40% without altering TPT. The +dP/dtmax value increased concomitantly with the -dP/dtmax values, thus no changes in R was observed. In MH muscle, PT was first potentiated (0.5-1.0 vol% halothane) and then depressed (2.0-3.0 vol% halothane). TPT and +dP/dtmax were not altered whereas RT1/2 increased progressively with concomitant decrease in -dP/dtmax, thus R increased by nearly 40%. The amplitude of MH muscle contracture with stepwise concentrations of halothane was correlated with the increase of RT1/2 and R, and the decrease of -dP/dtmax. These results suggest that halothane alters the relaxation phase more than the contraction phase in MH human skeletal muscle compared to normal muscle.

The brachial plexus was identified by electrical stimulation before interscalene block with 30 mL 0.5% bupivacaine and adrenaline 1:200,000. During injection, compression was applied with a finger proximal to the injection site. Spirometric measurements were made before the block, and then at 5 min, 10 min, 20 min and 4 h after the injection. Diaphragmatic excursion was measured radiographically before the block, and at 15 min and 4 h afterwards. In 25 patients studied, spirometric measurements decreased. Twenty minutes after the injection, the forced vital capacity was 27% less, forced expiratory volume at 1 s 34% less and peak expiratory flow rate 15% less (all P < 0.05). Right diaphragmatic excursion decreased from 4.5 cm (SD 1.2 cm) to 1.8 cm (0.6 cm) at 15 mins and to 1.1 cm (0.6 cm) at 4 h (P < 0.05). Identification of the plexus by electric stimulation combined with finger compression above the injection site did not prevent diaphragmatic paresis.

Background: To determine if alteration in the function of the sodium channel may in turn modify halothane-induced changes in mechanical responses of muscle bundles from patients susceptible to malignant hyperthermia (MH)., Methods: Mechanical responses of muscle bundles from 12 MH-susceptible and 20 MH non-susceptible patients were measured prior to and during administration of halothane alone and in the presence of 10 microM veratridine, an inhibitor of sodium channel inactivation. Peak tension (PT), time to peak tension (TPT), positive peak of isometric tension derivative (+dP/dtmax) were used to characterize the inotropic state. Analysis of relaxation process was performed using half relaxation time (RT 1/2) and the negative peak of isometric tension derivative (-dP/dtmax). The ratio (R) = (+dP/dtmax)/(-dP/dtmax) was used to measure the coupling between contraction and relaxation under isometric condition., Results: Veratridine significantly enhanced the 0.5, 1, 2 and 3 vol% halothane-induced contracture and induced a negative inotropic effect in MH-susceptible muscle bundles. R increased by nearly 90% indicating that the combined effects were more pronounced in the relaxation phase. In MH non-susceptible muscle, veratridine did not significantly enhance the effects of halothane., Conclusions: These results on cut MH-susceptible human muscle bundles support the hypothesis that halothane-induced contracture in MH can be modified by the binding of an inhibitor of sodium channel inactivation.

Objective: To assess the performance of the COPA device during general anaesthesia., Study Design: Prospective, clinical, open study., Patients: Eighty patients scheduled for short elective surgical procedures under general anaesthesia not requiring tracheal intubation., Method: After premedication (midazolam, atropine), anaesthesia was induced with propofol (154 +/- 40 mg = 2.47 +/- 0.8 mg.kg-1) and alfentanil (1.14 +/- 0.43 mg). The COPA device was inserted in a fashion similar to a Guedel airway device. The device was evaluated on the following criteria: correct choice of COPA size, ease of insertion, ability to obtain or maintain patent airway. Adverse reactions were noted, such as coughing, nausea, regurgitation, inhalation, and sore throat. The overall rating of the COPA as a "hand free device" was evaluated on the basis of excellent, good, fair, and poor., Results: Insertion of the device was easy and in 70 cases successful on the first attempt. Jaw thrust on head tilt was necessary in half the cases. No patient necessitated intubation because of hypoxaemia or airway obstruction. Adverse reactions occurred in few cases and consisted of sore throat (always moderate) in 10% of the cases. COPA was evaluated as excellent or good in 80% of the cases., Conclusion: COPA is a convenient device for airway management in fasting patients undergoing general anaesthesia for elective surgery in the supine position, in whom tracheal intubation is not indicated.

The Cook airway exchange catheter is mainly used in ICU patients to exchange endotracheal tubes. We report three cases where this device was used during anaesthesia in patients with damaged tubes in critical circumstances (oropharyngeal bleeding, head and neck surgery). It allowed a fast and atraumatic exchange of the tubes.

Malignant hyperthermia (MH) is a potentially fatal autosomal dominant disorder of skeletal muscle and is triggered in susceptible people by all commonly used inhalation anaesthetics and depolarizing neuromuscular blocking agents. To date, eight mutations in the skeletal muscle ryanodine receptor gene (RYR1) have been identified in malignant hyperthermia susceptible (MHS) and central core disease (CCD) cases. We have screened the RYR1 gene in affected individuals for novel MHS mutations by single stranded conformational polymorphism (SSCP) analysis and have identified a G to T transition mutation which results in the replacement of a conserved arginine (Arg) at position 614 with a leucine (Leu). The Arg614Leu mutation was present in three unrelated MHS individuals of 151 investigated. The mutation was not detected in 148 normal chromosomes and segregated precisely with MHS in family members from one of the probands where DNA was available for analysis. This mutation occurs at the same position as the previously identified Arg to Cys mutation reported in all cases of porcine MH and in approximately 5% of human MH. A comparison of the phenotypes of the Arg614Leu and Arg614Cys probands is presented.

Background: Determination of sensitivity and specificity of the in vitro contracture test (IVCT) for malignant hyperthermia (MH) susceptibility using the European MH Group (EMHG) protocol has been performed in some laboratories but only on a small sample from the combined EMHG. Thus, the purpose of the present study was to determine combined EMHG sensitivity and specificity of the test., Methods: Results of IVCT of patients with previous fulminant MH and normal, low-risk subjects (controls) were collected from 22 centres of the EMHG. IVCT was performed according to the EMHG protocol. Patients were included in the study if the clinical crisis had a score of at least 50 points with the Clinical Grading Scale. Low-risk subjects were included provided they did not belong to a family with known MH susceptibility, they had not developed any signs of MH at previous anaesthetics, and they did not suffer from any neuromuscular disease. For inclusion of both MH patients and low-risk subjects, at least 1 muscle bundle in the IVCT should have twitches of 10 mN (1 g) or more. For evaluation of individual tests, only muscle bundles with twitch heights of 10 mN (1 g) or more were used., Results: A total of 1502 probands had undergone IVCT because of a previous anaesthesia with symptoms and signs suggestive of MH. Of these, 119 had clinical scores of 50 and above. From these 119 MH-suspected patients and from 202 low-risk subjects, IVCT data were collected. Subsequently, 14 MH-suspected patients were excluded from further analysis for the following reasons: In 3 patients, the suspected MH episode could be fully explained by diseases other than MH; in 11 MHS patients, IVCT was incomplete (n = 1), data were lost (n = 3), or none of the muscle bundles fulfilled twitch criteria (n = 7). Of the remaining 105 MH-suspected patients, 89 were MHS, 10 MHEh, 5 MHEc, and one MHN. Thus, we observed a diagnostic sensitivity of the IVCT of 99.0% if the MHE group is considered susceptible (95% confidence interval 94.8-100.0%). Of the 202 low-risk subjects, 3 were MHS, 5 MHEh, 5 MHEc, and 189 MHN. This gives a specificity of the IVCT of 93.6% (95% confidence interval 89.2-96.5%)., Conclusion: The IVCT for diagnosis of MH susceptibility in Europe has a high sensitivity and a satisfactory specificity.

The phenotype of susceptibility to malignant hyperthermia (MHS); can only be detected reliably by the in vitro caffeine-halothane contracture test (CHCT). Enhanced sensitivity of the calcium-induced calcium release mechanism is responsible for the exaggerated contracture response of skeletal muscle fibers from MHS patients to halothane and caffeine. Chlorocresol was demonstrated to be a potent activator of Ca++ release from skeletal muscle sarcoplasmic reticulum. This effect is probably mediated through action on a ryanodine sensitive Ca++ release channel known to be more sensitive in MH. We studied the effect of chlorocresol on the mechanical contracture response of skeletal muscle from patients presenting for the in vitro CHCT. Chlorocresol induces contracture response in a concentration 1/200 of that of caffeine in muscle strips from MH patients. By adding chlorocresol to the protocol of the CHCT, there is clearer discrimination between the responses of MH patients and normal subjects can be achieved.