[Anaesthetic management for caesarean delivery and Creutzfeldt-Jakob disease]

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.

Hip-flexed postures do not affect local anaesthetic spread following induction of epidural analgesia for labour

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.

Le propofol et l'AIVOC en neuro-anesthésie

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.

[Amniotic fluid embolism suspected in a case of seizure and mild uterine haemorrhage with activation of coagulation and fibrinolysis]

After a normal pregnancy and labour in a 29-year-old parturient, a single seizure followed by a transient headache was observed during the uterine revision for placental retention. Mild uterine haemorrhage of 150 ml per hour without any uterine atony was associated with activation of clotting and fibrinolysis (decrease of fibrinogen, elevated fibrin soluble complexes and D-dimers). A ten fold value of foetal blood cells in maternal serum suggested the diagnosis of amniotic fluid embolism. Atypical forms of amniotic fluid embolism and their diagnosis are discussed.

Analgésie et anesthésie obstétricale chez les patientes atteintes de sclérose en plaques

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.

[Evaluation of verification of brain death and coordination with hospital organ procurement at the University Hospital at Lille]

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.

[Pneumocephalus after spinal anesthesia]

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.

[Postoperative analgesia in pediatric neurosurgery]

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.

[Anesthetic particularities of stereotaxic neurosurgery]

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.

[Follow-up study of head-injured children]

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.

[Malignant hyperthermia: new developments in diagnosis and clinical management]

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).

Congenital myopathy with central cores and fingerprint bodies in association with malignant hyperthermia susceptibility

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.

Use of inhaled nitric oxide for emergency Cesarean section in a woman with unexpected primary pulmonary hypertension

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.

[Recombinant hirudin in neurosurgery]

We report the case of a 70-year-old woman with paraplegia resulting from spinal cord compression secondary to an epidural haematoma. Because of an arrhythmia, a mitral valve replacement and the high risk of venous thrombosis, an anticoagulant treatment was introduced postoperatively. The patient having previously developed an type II heparin-induced thrombocytopaenia, a treatment by lepirudine was established successfully.

[Anesthetic management of obstetrical labor in a parturient with muscular carnitine palmitoyl transferase deficiency]

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.

[Caffeine skinned fiber tension test: application to the diagnosis of susceptibility to malignant hyperthermia]

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.

[Obstetric analgesia: peridural analgesia versus combined spinal and peridural analgesia]

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.

Parturition and angioneurotic oedema

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.

[Intraoperative exchange of the endotracheal tube using the Cook C-CAE airway exchange catheter]

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.

-The clinical use of the cuffed oropharyngeal airway (COPA)-

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.

[Malignant hyperthermia and appendicular sepsis. Can they be differentiated during surgical procedure?]

OBJECTIVE

To assess the possibility to differentiate clinically intraoperative malignant hyperthermia (MH) and sepsis.

STUDY DESIGN

Comparative retrospective study of clinical cases.

PATIENTS

Sixteen patients operated on for acute appendicitis and developing clinical signs of MH confirmed or not by in vitro caffeine halothane contracture tests (IVCT).

METHOD

To isolate the patients' characteristics with regard to the diagnosis of sepsis and MH crisis. To compare both groups of clinical features with results of IVCT.

RESULTS

The diagnosis of MH sensitivity has been excluded in ten hyperthermic patients and confirmed in four others with IVCT. No correlation was existing between the importance of perioperative sepsis, MH features and IVTC results.

CONCLUSIONS

This study confirmed the difficulty to differentiate clinically MH and sepsis during surgery. Considering the severe outcome of MH crisis, it is recommended to start the specific therapy even in case of appendicular sepsis.

An attempt to prevent spread of local anaesthetic to the phrenic nerve by compression above the injection site during the interscalene brachial plexus block

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.

Detection of a novel mutation at amino acid position 614 in the ryanodine receptor in malignant hyperthermia

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.

In vitro contracture test for diagnosis of malignant hyperthermia following the protocol of the European MH Group: results of testing patients surviving fulminant MH and unrelated low-risk subjects. The European Malignant Hyperthermia Group

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.

Identification of heterozygous and homozygous individuals with the novel RYR1 mutation Cys35Arg in a large kindred

BACKGROUND

Malignant hyperthermia (MH) is a potentially fatal, often autosomal dominant, disorder of skeletal muscle and is triggered in susceptible people by all commonly used inhalational anesthetics. In this article, the authors describe a malignant hyperthermia susceptible (MHS) kindred in which both parents of the proband are MHS and are first-degree cousins. Haplotype analysis in this kindred with chromosome 19 linked markers revealed that the proband and another sibling were homozygous for the affected RYR1 allele.

METHODS

Eighteen members of this large pedigree were investigated, with a clinical examination for signs of a myopathy, a caffeine halothane contracture test, a histo-enzymologic study on the muscle biopsies, and linkage analysis on genomic DNA isolated from family blood samples. RYR1 cDNA was amplified by polymerase chain reaction and was cloned and sequenced, facilitating mutation detection.

RESULTS

Linkage analysis demonstrated linkage between RYR1-linked markers and MH susceptibility in this family. DNA sequencing identified a T to C transition at nucleotide position 103, resulting in the substitution of an arginine for cysteine 35, representing the most N-terminal mutation reported to date in the RYR1 gene. This mutation segregates fully with the MHS trait, generating a lod score of 4.65 in favor of linkage to MHS at a recombination frequency of 0.0.

CONCLUSIONS

The proband in this kindred is the first reported homozygote to have presented with an MH episode. The homozygotes in this pedigree do not have an overt myopathy. The sensitivity of muscle samples to caffeine clearly distinguished the two homozygotes from other heterozygous-susceptible individuals. No clear differentiation was observed with the halothane contracture results.

In vitro human masseter muscle hypersensitivity: a possible explanation for increase in masseter tone

To determine whether a difference in fiber-type caffeine and Ca2+ sensitivities exists between human masseter and vastus lateralis skeletal muscle, we compared the fiber-type caffeine sensitivities in chemically skinned muscle fibers from 13 masseter and 18 vastus lateralis muscles. Caffeine sensitivity was defined as the threshold concentration inducing > 10% of the maximal tension obtained after the fiber was loaded with a 1.6 x 10(-2) mM Ca2+ solution for 30 s. Significant difference in the mean caffeine sensitivity was found between type I masseter fibers [2.57 +/- 1.32 (SD) mM] vs. type I (6.02 +/- 1.74 mM) and type II vastus lateralis fibers (11.25 +/- 3.13 mM). Maximal Ca(2+)-activated force per cross-sectional area was significantly different between masseter and vastus lateralis fibers. However, the Ca2+ concentration corresponding to half-maximal tension (pCa50) was not significantly different between type I masseter (pCa50 5.9 +/- 0.02) and type I vastus lateralis muscle (pCa50 6.01 +/- 0.08). These results suggest that the increase in caffeine sensitivity of masseter muscle reflects the presence of a low reactivity threshold of the sarcoplasmic reticulum.

[Anesthesia and critical care for endovascular occlusion of ruptured intracranial aneurysms with electrically detachable coils]

The endovascular occlusion of ruptured intracranial aneurysms with electrically detachable coils is a therapeutic approach which seems to be a promising technique. General anaesthesia is considered as being the most adapted for its realisation, as its provides complete immobility and as controlled ventilation and extended monitoring offer optimal conditions for undelayed treatment of haemorrhagic and thromboembolic complications. The available equipment should be the same as that used for conventional surgical treatment of ruptured aneurysms. Anticoagulation is required to prevent thromboembolic complications during and after the procedure. Most teams administer heparin.

[Gamstorp's disease and pregnancy. A case report]

Gamstorp's disease or hyperkaliemic periodic paralysis is a rare pathology leading to spells of generalized hypotonia due to hyperkaliema. It is hard to say how far pregnancy affects the course of the disease and what is the impact of the disease on pregnancy. We report a case of Gamstorp's disease during pregnancy and we insist on the fact that because it can be crippling during its acute phases, close surveillance is needed during pregnancy. Screening for malignant hyperthermia should be carried out. During labour, kaliemia level should be monitored repeatedly and the expulsion phase kept as short as possible if necessary by forceps delivery.

Evaluation of the Augustine Guide for difficult tracheal intubation

Successful tracheal intubation with Augustine Guide (Augustine Medical, Inc., Eden Prairie, MN) in patients with normal airways has recently been described. There are no studies describing Augustine Guide (AG) use in patients with difficult airways. Accordingly, we studied AG intubation in a population of patients with expected difficult airways due to cervical spine pathology, limited mouth opening, obesity, facial trauma or deformity due to previous operation or radiation and in patients with unexpectedly difficult airways. A total of 44 patients were studied. The AG was used as a primary intubating tool in patients with known difficult airways (n = 36) and as a secondary intubating tool in patients with unexpected inability to intubate using conventional direct laryngoscopy (n = 8). Airway difficulty was predicted by history and physical examination. Intubations were performed under general anaesthesia in 40 of the 44 patients studied. In four patients with predictably difficult airways, topical anaesthesia and sedation were used. Backup methods to achieve intubation were available. Thirty-two of the 36 with known or suspected difficult airways were classified as Mallampati Class III or IV. In the remaining eight patients the preoperative examination suggested an easy airway; however, after induction of general anaesthesia, their laryngeal inlet could not be seen using direct laryngoscopy. Using the AG, all were intubated successfully (36/44 at the first attempt, in 8/44 repositioning of the AG to allow successful laryngeal entry of the stylet was necessary). There were no failures or complications secondary to AG use. This study shows that the AG is a useful device for oral tracheal intubation in patients with known or unexpectedly difficult airways.

[Cervicofacial cellulitis of dental origin and tracheal intubation]

OBJECTIVES

To evaluate the difficulty of intubation in relation with the localisation and spread of cervico-facial cellulitis of odontogenic origin and to recognize the optimal technique of intubation in such circumstances.

STUDY DESIGN

Prospective clinical open study.

PATIENTS

Hundred patients, including 16 children, undergoing surgical drainage of a cervico-facial cellulitis of odontogenic origin under general anesthesia were studied.

METHODS

Difficulty of intubation was evaluated with the following four criteria: active mouth opening in the awake patient, Mallampati's classifying system, presence of trismus, clinical and radiological control of localisation and extension of the cellulitis (mandibular, maxillar or mouth floor). In case of a foreseen difficult intubation, a fibrescope was used in the awake patient. Otherwise the endotracheal tube was inserted after administration of propofol (3 mg.k-1) and alfentanil (10 to 20 micrograms.kg-1). A Cormack's grading was performed during intubation.

RESULTS

Mouth opening depended on the localisation of the cellulitis. Trismus occurred more often with mandibular than maxillary localisations. Trismus and a Mallampati's class > 2 were associated with difficulty in intubation (Cormack's grade > 2), except in maxillary localisations.

CONCLUSIONS

The localisation of cellulitis of odontogenic origin is responsible for the difficulty grade of intubation. Awake fibreoptic intubation should be systematically performed in patients with a floor of the mouth cellulitis to reduce the risk of rupture of the abscess by a laryngoscope blade. As trismus associated with mandibular localisations is not relieved by general anaesthesia, awake fibreoptic endotracheal intubation should be preferred.

[Mild hypothermia and cerebral protection]

To define the part played by mild-to-moderate hypothermia in neuroprotection, it is necessary to take into account the thermoregulatory responses that occur in the normal human as the change in central temperature exceeds 0.2 degrees C. The mechanisms induced by cold are cutaneous vasoconstriction and shivering. They must be suppressed before starting controlled hypothermia. In these conditions, controlled moderate hypothermia between 32 and 35 degrees C does not seem to have deleterious side-effects, especially on coagulation. Caution is needed with the analysis of the numerous papers reporting experiments concerning the effects of moderate hypothermia in animals with induced cerebral ischaemia because of significant differences in the study designs. These differences concern mainly the time of onset of hypothermia, viz before or after ischaemia, the fact that the ischaemia is either global or focal, that it is caused by vascular occlusion posttraumatic or initiated by hypo or hyperglycemia. Some differences are also existing in the criteria used to appreciate the neuronal damage, as well as in the level of temperature and the site where it is measured. The mechanism of neuroprotection from moderate hypothermia seems to be not only a decrease in cerebral metabolism, but also involves a specific action on some intra-cellular events such as the blocking of the release of glutamate and of lipid peroxydation in brain tissue. An indirect proof of the neuroprotective effect of moderate hypothermia is the increase in the neuronal damage induced by moderate hyperthermia. It is conceivable that moderate hypothermia could exert a better neuroprotective effect than the drugs having this reputation, such as barbiturates, isoflurane and propofol.(ABSTRACT TRUNCATED AT 250 WORDS)

Mutation screening of the RYR1 gene in malignant hyperthermia: detection of a novel Tyr to Ser mutation in a pedigree with associated central cores

The ryanodine receptor gene (RYR1) has been shown to be mutated in a small number of malignant hyperthermia (MH) pedigrees. Missense mutations in this gene have also been identified in two families with central core disease (CCD), a rare myopathy closely associated with MH. In an effort to identify other RYR1 mutations responsible for MH and CCD, we used a SSCP approach to screen the RYR1 gene for mutations in a family exhibiting susceptibility to MH (MHS) where some of the MHS individuals display core regions in their muscle. Sequence analysis of a unique aberrant SSCP has allowed us to identify a point mutation cosegregating with MHS in the described family. The mutation changes a conserved tyrosine residue at position 522 to a serine residue. This mutation is positioned relatively close to five of the six MHS/CCD mutations known to date and provides further evidence that MHS/CCD mutations may cluster in the amino terminal region of the RYR1 protein.

Detection of a novel common mutation in the ryanodine receptor gene in malignant hyperthermia: implications for diagnosis and heterogeneity studies

Malignant hyperthermia (MH) is a potentially fatal autosomal dominant disorder of skeletal muscle and is triggered in susceptible people by all commonly used inhalational anaesthetics. To date, the ryanodine receptor gene (RYR1) has been shown to be mutated in a small number of malignant hyperthermia susceptible (MHS) cases. To determine if a common RYR1 mutation exists that might account for a significant number of MHS cases, we have investigated the RYR1 gene in unrelated patients for the presence of new mutations by the single-stranded conformation polymorphism method and have identified a novel Gly341Arg mutation which accounts for approximately 10% of Caucasian MHS cases. The implications of this common mutation in MHS diagnosis and heterogeneity studies are discussed.

[Lumbar disk herniation with surgical option: general versus local anesthesia. Round table]

Lumbar disc hernia is a frequent pathology whose treatment remains essentially surgical. The type of anesthesia can be general anesthesia with intubation and controlled ventilation, both mandatory due to the position, peridural or spinal anesthesia. The usual position is knee-chest position which impairs circulation and ventilation if some precaution are not taken. Spinal anesthesia has been chosen in more than 40% of the patients by Lille CHU Team. This choice is justified by the important level of satisfaction of the patients and the absence of complications due to the anesthesia in a series of 1871 consecutive spinal anesthesia for lumbar disc surgery.