Existe-t-il encore une place pour la dopamine en réanimation pédiatrique ?

Dopamine is mostly used in patients with cardiogenic or septic shock, but its place in critical care medicine is often questioned. Dopamine, of which pharmacology in children is variable, is prescribed for its inotropic effect, associated with an increase in cardiac output and at a lesser degree blood pressure. Beneficial effects (need for renal replacement therapy and mortality) of low dose in patients at risk of, or with acute renal failure are not demonstrated. Dopamine has numerous potential deleterious effects on local circulations (pulmonary, cerebral, coronary and cutaneous), respiratory function, gastroduodenal motility, endocrine function (further depression of the hypothalamic-pituitary axis induced by stress) and immunity (partially due to decreased production of prolactin). Finally, in shocked adults dopamine infusion might be associated with an increase in mortality rate. Dopamine remains the most prescribed catecholamine, either in adults or children. It still is one of the first line drug included in the recent recommendations for the treatment of septic shock (norepinephrine tends to replace it), cardiogenic shock (dobutamine is the first drug), severe head trauma, and organ donor in cerebral death. In conclusion, if dopamine is today less used, there is no proof that its deleterious effects are associated with an excess of mortality. Thus, dopamine still is part of the stock of drugs that act on the cardiocirculatory system (but for how long?).     

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.     

Accident vasculaire cérébral hémorragique : nouveautés sur la prise en charge

Haemorrhagic stroke is frequent and associated with a high mortality and morbidity. Less than 30% of patients are still alive five years after onset and few patients regain functional independence. The worsening effect of anticoagulation has been demonstrated and the failure to rapidly normalize coagulation further increases haematoma expansion. In a recent phase II trial, recombinant activated factor VII given within 4 hours of stroke onset, reduced haematoma growth, mortality and disability. An aggressive blood pressure and intracranial pressure control early after the haemorrhage seems beneficial. A large prospective randomized study (the STICH trial) did not demonstrate any beneficial effect of surgery.     

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.     

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'apprentissage des gestes invasifs et de la gestion d'une situation critique pose-t-il des problèmes éthiques en anesthésie–réanimation ?

OBJECTIVE: To provide information on morbidity and ethical questions associated with learning of invasive techniques (tracheal intubation, positioning of central venous or epidural catheters) and management of anaphylactic shock. STUDY DESIGN: Retrospective survey. METHODS: Written questionnaire to 54 anaesthesiologists and 55 residents. RESULTS: Training was primarily performed by residents having a 6 months-experience for general anaesthesia and by more experienced residents for epidural analgesia. Residents observed first two or three procedures performed by seniors, but did not have theoretical lectures in 30 to 50% of cases. Dead bodies or manikins were rarely used. Despite the presence of experienced anaesthesiologists during the first attempts, there was a high morbidity rate which was considered by 22 to 37% of the interviewed anaesthesiologists a loss of benefit for the patients. Despite a high level of coaching, a high morbidity rate was associated with the first attempts. However, only few residents explicitly stated to be concerned by ethical questions. Among anaesthesiologists, who had yet to manage anaphylactic shock, 21 and 35% of them reported that diagnostic and treatment could have been performed faster. Virtual learning was misunderstood but 46% of anaesthesiologist described numerous advantages in using simulator of anaesthesia. CONCLUSION: Despite an apparent morbidity with a loss of benefit, informed consent of the patients were rarely obtained.     

Chocs hémorragiques au cours de dérivation interne du liquide céphalorachidien. Faut-il revoir la pratique anesthésique ou chirurgicale ?

We report two cases of perioperative haemorrhagic shock after accidental puncture of trunc vessels, during emergency shunt procedures in children who suffer of severe intracranial hypertension. In both cases it's the peritoneal internalization of the shunt with Portnoy trocar which is responsible of these deep vascular wounds. Evolution was favourable in both cases with cardiovascular resuscitation, transfusion and surgical haemostatic correction. Few days later, an internal shunt was performed in the second patient, while the first patient did not need shunt anymore. These two accidents lead to the discussion of the surgical procedure with surgeons, in order to have a better prevention against this complication. We also discuss our anaesthesiological practice from preoperative to perioperative period of this usually non-haemorrhagic surgical procedure.     

Déficit génétique de la butyrylcholinestérase : comment interpréter l'activité cholinestérasique chez le jeune enfant ?

We report the case of a prolonged neuromuscular blockade in an 18-month-old age girl following administration of a usual dose of succinylcholine. The diagnosis was highly suggested by the clinical history while cholinesterase activity was included in adult normal values but below values of a personal series of 41 small children. The familial analysis of dibucaine and fluoride number confirmed the hypothesis of an atypical variant (AA phenotype). The cholinesterase activity is higher in small children than in adult and has to be analysed according to the age.     

Anesthésiques généraux en pédiatrie : risque ou bénéfice ?

The practice of paediatric anaesthesia has changed during the last 25 years, with a noticeable reduction of mortality and serious morbidity. This improvement results in part from the use of new anaesthetic agents which large therapeutic interval regarding cardiovascular effects. Parallel to this advance and following experimental or clinical studies in neurosciences, some new concerns have emerged regarding short and long time consequences of anaesthesia. Indeed, postoperative hyperalgesia due to opioids, emergence agitation and postoperative maladaptive behavioural changes are widely described in children, in the same way the potential epileptogenic effect of sevoflurane is demonstrated. Thus the hypothetical cerebral toxicity leads us to reconsider our practice. Basically, monitoring of cerebral cortical effects of hypnotics is now possible from automated devices based on EEG, allowing us to control the administration of hypnotic agents. The therapeutic interval of these agents, previously determined between movement at incision and deleterious cardiovascular effect, may be revisited with a cerebral approach, with the risk of memorisation for the lower limit and the risk of cerebral over dosage for the upper limit. Lastly, further experimental and clinical studies are required to analyse the effects of the anaesthetic agents on the brain of the neonate, and the interest of the cerebral monitoring in this population.