Le syndrome de perte de sel d'origine cérébrale existe-t-il ?

Increased natriuresis is a frequent situation after subarachnoid haemorrhage (SAH). It may be responsible for hyponatremia, which can be dangerous in case of severe hypo-osmolarity or hypovolemia. Inappropriate secretion of antidiuretic hormone or cerebral salt wasting syndrome (CSWS) have been incriminated for hyponatremia after SAH, but it remains difficult to distinguish between both syndromes. There are many explanations for increased natriuresis after SAH, depending on the level of blood pressure, the volemia, and the presence or not of natriuretic peptides. The cerebral insult and the treatments, which are done to fight against elevated intracranial pressure or vasospasm, can modify any of these parameters. So it appears that the word “cerebral” in CSWS is probably not a good term and it would be better to talk about appropriate or non-appropriate natriuretic response. Corticoïds or urea can be useful for controlling hypernatriuresis.     

Repos de sécurité : quels enjeux ?

In 2003 were promulgated the texts regulating rest and safety, in the USA (approved by the ACGME) and in France (January 9th, 2001 and September 14th, 2001). The institution of the "rest for safety", an eleven hours duration interruption of activity, immediately after a night-call, can be viewed as a progress in the search for safety. Several studies showed a link between excessive work hours and occurrence of medical incidents related to tiredness. However published data do not show a link between tiredness and patients endangering. The tiredness resulting from sleep deprivation and disturbances in circadian rhythms is a cumulative phenomenon erased by a period of rest. In spite of a large individual variability, tiredness increases anxiety scores, irritability, depression and it deteriorates cognitive performances. The concept of "prophylactic" rest considers that a subject cannot start, rested, a work if he did not sleep at least 5 hours the previous night, or 12 hours during the previous 48 hours. The second important aspect of the rest for safety is the long-term prevention of potential pathologies in medical staff, in particular burnout syndrome. In our profession, night calls are considered most stressful; the psychological stress related to anticipation and night context causes measurable cardiovascular disturbances in anesthesiologists. Shift-work sleep disorders may induce gastric ulcers, heart attacks, metabolic syndrome, depression and accidents related to somnolence. Long duration work-hours, accompanied by sleep deprivation, may double the risk of car accidents in junior physicians, in whom vigilance levels can compare with those of patients concerned by narcolepsy or with the cognitive disturbances induced by alcohol intoxication. Reduced work-hours improve vigilance and divide by three the rate of serious medical errors. True opportunities of sleep and control of sleep duration at the individual level could be suggested. The idea that taking the necessary rest would be synonymous with a decrease of efficiency in patient care is not demonstrated, but the danger of a poorer information transmission should be handed with an optimization of our manpower and organization. Aging is accompanied by a progressive disorganization of sleep. The foreseeable shortage of manpower, synonymous with aging of the medical actors and increased vulnerability to tiredness, is a posteriori the justification of the institution of the rest for safety.     

Médiatisation et « greffe de visage » ou « à qui appartient la greffe de visage » ?

Mediatisation of a scientific event could be neither controlled, nor verifiable. The experience which has been lived through the first worldwide allotransplantation of composite tissues of the face confirms that the actors of a surgical innovation are not the owners. Because there is neither confidentiality nor possible patent. Curiously the scientific world, providing with a sharing ethic, which rightly privileges the free spreading of knowledge in the way that most people could benefit of it. Obviously it is made without denied controversy, for truth as purpose. This scientific word that way joins the media one, with a specific ethic of the duty of information, but also interested in mercantile preoccupations quick to cultivate controversy not to enlighten this truth but to better sell pictures or papers. Than the author should only sustain this instrumentation which could certainly flatter him, and from which he could used, but in reality that paralysed him a little to go on in serenity with his shadow worker way.     

L'anesthésie comme cause de souffrance fœtale ?

ObjectiveTo describe the effects of anaesthetic techniques and agents on the risk of foetal distress during labour pain relief and anaesthesia for caesarean section.Study designData on obstetric anaesthesia- and analgesia-induced fœtal distress were searched in Medline database using Mesh terms: foetal distress, anaesthesia, analgesia, labour, caesarean section, and umbilical artery pH. Trials published in English or French language were selected.ResultsBecause of their haemodynamic effects, regional anaesthesia and analgesia, especially spinal anaesthesia for Caesarean section, could induce a decrease in umbilical artery pH (UApH). Moreover, intravenous ephedrine, especially when used in large doses can worsen the acidosis. Labour epidural analgesia is associated with a better acid-base balance than systemic analgesia. Experimental studies have demonstrated harmful effects of systemic opioids and hypnotic drugs on UApH and the foetal brain respectively. Clinical implications of these potentially detrimental effects remain to be determined.ConclusionAll obstetric anaesthesia and analgesia techniques are associated with a theoretical risk of fetal distress, but given the fact that regional anaesthesia techniques are also associated with well-demonstrated benefits for the mother and the newborn, the latter remain the preferred choice in obstetric practice.     

Le certificat de décès : comment le remplir et pourquoi ?

The death certificate must be established within 24 hours following the death and handed to the mayor. The obligation to place in the coffin immediately is planned by a defined list of contagious diseases. Medicolegal obstacle must be ticked if there is a doubt on the cause of death. In order to look into the causes of the death, swabs can be asked by the physician. It is a medical or scientific autopsy to look into the causes of the death apart from a juridical procedure. The presence of a battery prosthesis (pacemaker) must be specified, so that it can be removed by a physician or a thanatopractionner before the placing in the coffin. Death certificate is passed on by the city hall to Insee, which updates the identification national register of physical people. Inserm receives anonymous data of the causes of death allowing to establish the mortality national statistics. In the absence of medicolegal obstacle or obligation to place in the coffin immediately, funeral operations can begin: preservation care, body transport, placing in the coffin and finally burial or cremation.     

Les cavernomes intramédullaires : série personnelle de 24 cas

Intramedullary cavernomas are rare, but with routinely use of MRI detection has improved, raising the problem of choosing the adequate management approach: conservative or surgical. Cavernomas are vascular malformations, but, as hemangioblastomas they appear as vascular tumors of the spinal cord. They can be durably asymptomatic. The symptoms are a progressive clinical deterioration or acute spinal dysfunction (tetra or paraplegia) in case of hemorrhage. Cavernomas have a typical aspect with MRI in contrast with intramedullary gliomas. The lesion is often superficial, covered by the pia-mater, visible immediately after opening the dura, the approach is direct; but in few cases the cavernoma is deep seated in the spinal cord and not visible, the approach is through the midline. It is recommended to perform a complete “en bloc” resection. A yearly MRI control is necessary to search possible "de novo" cases.     

Hypothermie après rachianesthésie : rôle de la morphine ?

Spinal anaesthesia is the gold standard for elective caesarean section. This technique presents several adverse effects. We report a severe case of hypothermia (33.3 degrees C) after spinal administration of bupivacaine (10 mg) and morphine (100 microg) for elective caesarean section. After excluding other causes of hypothermia, this one could be explained by both the own effects of local anaesthesia (i.e. peripheral vasodilatation) and by the central effect of intrathecal morphine. Because hypothermia is not predictable after spinal injection of morphine both monitoring of central temperature and active warming of the patients could be proposed. Naloxone has been proposed in a case of hypothermia related to spinal injection of morphine.     

La pratique des curages ganglionnaires est-elle harmonieuse ? Analyse rétrospective de 330 cas

Aim

The aim of our study was to make evident the huge variability in lymph node dissection practice.

Material and methods

Therefore a retrospective study was conducted on 330 patients assessed for cervical, axillary or groin dissections. In each case the authors collected the primary diagnosis and clinical stage indicating lymph node clearance, identity of the surgeon and the pathologist, surgical technique including skin incision and landmarks of tissue removal, size of the clearance, and number of lymph nodes removed. Correlations between diagnosis, surgeon's or pathologist's identity, size of the clearance and number of nodes were analyzed using non-parametric tests.

Results

Standardized procedures as axillary dissections occurred few differences between surgeons. In groin or cervical dissections statistical differences were made evident with great technical variability. There was a positive correlation between size of the piece of lymphadenectomy and number of lymph nodes removed.

Conclusion

Standardized procedures as axillary dissections provide few variations. Cervical and especially groin dissections should be harmonized, published and taught harmoniously in schools of surgery. So the expression “regional lymph node clearance” would mean.     

Faut-il réévaluer le risque d'une embolie gazeuse compliquant une intervention avec insufflation de gaz carbonique ?

Due to the characteristics of the carbon dioxide, gas embolism occurring during coelioscopy using this gas is usually considered as non critical. We report three observations of gas embolism which have occurred during laparoscopic surgery, one mild and two having led to death in spite of hyperbaric oxygen therapy. These observations prompted us to reevaluate the role of carbon dioxide in the severity of gas embolism.     

Quelle anesthésie pour les IRM en pédiatrie ? Résultats d'une enquête par Internet dans les CHU de France

Objective

To investigate the procedures used by French anaesthesiologists in children undergoing MRI.

Methods

A questionnaire was sent by Internet to every university hospital in France. Information concerning the specialty of the doctor in charge of the child, the age of the children, premedication, airway control, the agents used, presence of a specific recovery room, length of hospitalization and number of children undergoing MRI was obtained.

Results

Out of the 28 hospitals contacted, one did not reply and two did not perform anaesthesia for MRI. In 80% of cases, paediatric anaesthesiologists were in charge of the children. Only one team applied an age limit and performed sedation only in children over 10 kg. Specific monitoring for MRI was used by all teams. Premedication was given in 52% of cases. Parents were present during induction in 52% of cases. Sevoflurane was used in 52%, propofol in 40% and propofol with sufentanil in 8%. Presence of a venous line is systematic in 92% of cases. Intubation is systematic in 36% of cases, laryngeal mask in 20%, one or the other in 24%, and face mask and/or oral canula in 20%. The most widely used ventilation mode is spontaneous breathing (52%). All children go to the recovery room, which was close to the MRI unit in only 48% of cases and was less than 1 hour away in 72%. In 83% of cases, MRI is performed on a day-case basis and the number of procedures varies from 4 to 30 per week.

Conclusion

While there is no standard anaesthetic protocol in France for children undergoing MRI, only specialist teams undertake such procedures.     

Les respirateurs d'anesthésie de nouvelle génération vont-ils modifier notre pratique chez l'enfant ?

Because of specific paediatric respiratory physiology (mainly decreased compliance and functional residual capacity, increased O2 demand and CO2 production), ventilators for paediatric anaesthesia need to be powerful and able to deliver small volumes at a high rate without compression volume loss. The compensation of compliance now available on every anaesthesia machine, compensates for the volume of gas lost by compression in the circuit tubing allowing the tidal volume to reach preset commands, even for bellow in box respirators. Preset tidal volume is then totally delivered to the lung by volume-controlled ventilation because it becomes independent of total pulmonary compliance and fresh gas flow. Increased precision of electronic flowmeters and better air-tightness of circuits allow reducing with precision fresh gas flow to values approaching children's O2 consumption and N2O diffusion. New modes of ventilation are now available on anaesthesia machine. Pressure controlled mode, by increasing and maintaining mean airway pressures, ameliorates intrapulmonary gas distribution and compensates for the gas leak from uncuffed tracheal tubes. Unsteady tidal volume resulting from variation of total compliance, is the main drawback of pressure-controlled ventilation that may be overcome by using the "autoflow" mode (better described as a pressure controlled mode ensuring tidal volume) available with one of the last generation of ventilators. Increased accuracy and security of the mode "pressure assist" might increase the use of spontaneous ventilation in paediatric anaesthesia even for low weight children. However tidal volume remains variable with compliance and depth of anaesthesia, which may require several adjustments of ventilator's settings. The clinical conditions (mainly airway control) of pressure assist use for children less than 10 kg should be elucidated before recommending its use.     

Quelle sédation pour la prévention et le traitement de l'agression cérébrale secondaire ?

The aim of sedation and analgesia is to prevent secondary brain insult. The goals of sedation are the prevention and treatment of intracranial hypertension and systemic disorders. In such situation, the use of sedative and analgesic therapy should respect the rate of cerebral blood flow/cerebral oxygen consumption coupling while preserving cerebral perfusion pressure and decreasing the intracranial pressure. This treatment should have an analgesic and myorelaxing action with short and predictable time of action. The optimal agent with all these characteristics does not exist, but the combination of several pharmacological compounds may reach this goal. Benzodiazepines are the most frequently agents used. In most of cases they are associated with analgesics like opioids or ketamine. Opioids are the basis of analgesia because they do not produce brain haemodynamic alterations if arterial pressure is maintained. Ketamine, which use in this indication is matter of debate, has the advantage to maintain haemodynamics. Ketamine has no side effects on brain haemodynamics when used in combination with propofol or midazolam. Because of their side effects on haemodynamics and immune response, barbituric are no longer used as long term sedative agents. However, they are still recommended in cases of refractory intracranial hypertension. Propofol remains the optimal sedative agent because of its short duration action although its use is restricted because it is an expensive drug. Its use is recommended for short time sedation with or without opioids. The use of neuromuscular blockers should be focused on the patients with an intracranial hypertension refractory to standard treatment. The presence of brain damage in patients makes difficult to assess the level of sedation. One should avoid over sedation, which increases morbidity by prolongation of the duration of mechanical ventilation.     

Comment moduler la pression artérielle en cas de lésion cérébrale ?

One of the goals of the medical management of head injured patients is to get a cerebral perfusion pressure between 60 and 70 mmHg. To reach such a goal, catecholamines are used after fluid challenge. Systemic effects of catecholamines depend on their affinity for the receptors alpha and beta. The topical application of norepinephrine (alpha predominant) induced a vasoconstriction on large cerebral arteries only. Cerebral blood flow increased in the pericontusionnal area, suggesting a loss of autoregulation. The topical application of dopamine at low concentration relaxed large cerebral arteries. Dopamine increased cerebral blood flow in the pericontusional area but data suggest a possible raise in the volume of contusion. Four human comparative studies have been published. The first study, which was not randomized, showed an intracranial pressure increase associated with dopamine. Two randomized clinical trials, published by the same group, demonstrated a better predictability with norepinephrine. The fourth study did not find any difference regarding cerebral haemodynamics. In conclusion, the quality of data on the effects of catecholamines on cerebral haemodynamics of head injured patients do not make it possible to conclude about their use.