RESUMEN
Magnesium (Mg), a cofactor in numerous enzymatic reactions, is often ignored by clinicians, as the symptomatology of Mg depletion is not specific and usually associated with that of the cause of the depletion. Furthermore, the plasma Mg concentration (0.8 to 1.1 mmol.L-1) is only equivalent to one percent of the total body content. A Mg deficit may exist while plasma Mg concentration is normal. Therefore other techniques for Mg assessment, such as the repletion test, as well as red blood cell and lymphocyte concentrations have been used. A renewed interest for Mg occurred as numerous studies have shown the therapeutic efficiency of Mg and as the mechanisms of its haemodynamic effects have been recognized. Mg regulates Na-K-ATPase activity, K channels activity and, most of all, it is a natural calcium channel blocking agent. These properties explain its important place in electrophysiology of myocardial cells and the effects on the tension of smooth muscles, resulting in a vasodilation and a bronchodilation respectively. The antagonistic effect of Mg on calcium decreases the presynaptic release of acetylcholine at the neuromuscular junction and the release of epinephrine at the peripheral sympathetic nerves and the adrenals. Mg potentiates the effect of non-depolarizing muscle relaxants. A Mg deficiency occurs often in ICU patients, in alcoholics and during use of diuretics. Simultaneous administration of Mg is often required for treatment of potassium deficiency. Mg has an anti-arrhythmic effect towards digoxin-mediated dysrhythmias and torsades de pointes, and can be efficient in other arrhythmias. Systematic use of Mg seems to decrease mortality of acute myocardial infarction and is justified during cardiac surgery, often associated with hypomagnesemia, because of vasodilation of coronary arteries and in order to prevent occurrence of arrhythmias. Mg, because of its calcium channel blocking properties and as it lowers the release of epinephrine, is indicated for surgery of pheochromocytoma. In eclamptic and pre-eclamptic patients, the use of Mg is valuable, but not as an anti-epileptic agent. Other clinical uses of Mg have been proposed, but they are either anecdotal or of uncertain efficiency.
Asunto(s)
Anestesia , Cuidados Críticos , Deficiencia de Magnesio , Magnesio/fisiología , Fenómenos Fisiológicos Cardiovasculares , Sistema Nervioso Central/fisiología , Humanos , Magnesio/sangre , Cloruro de Magnesio/uso terapéutico , Deficiencia de Magnesio/diagnóstico , Deficiencia de Magnesio/etiología , Sulfato de Magnesio/uso terapéutico , Placa Motora/fisiologíaRESUMEN
Acute epiglottitis is an infectious disease causing a severe respiratory distress. Any attempt to move the child in the horizontal position or to examine his throat can result in cardiac arrest. Diagnosis, endotracheal intubation as well as decision making of the optimal time for extubation are greatly facilitated by the use of a fiberoptic bronchoscope. The device is a paediatric model (external diameter 3.6 mm with an operating channel). It is inserted through the nare in the child in the sitting position. Oxygen is delivered through a nasal tube. The examination is performed under local anaesthesia (lidocaine 0.5%). Midazolam is sometimes added via the rectal or i.v. route. The clinical signs are monitored as well as the heart rate and SpO2. The diagnosis of epiglottitis as it is visual, is very easy and rapid once the epiglottis is observed through the fibreoptic bronchoscope. The advantage of the examination under fibreoptic bronchoscope is to allow visualization without aggression or stimulation of the pharyngolaryngeal structures and without modification of the child's position. Endotracheal intubation, which is always required, is facilitated as the child is breathing spontaneously. The expiratory flow blows bubbles of saliva, which guide the bronchoscope to the glottis. When the internal diameter of the endotracheal tube is larger than 4 mm, the bronchoscope is used as a guide. When it is less than 4 mm. the bronchoscope is inserted in the trachea with a guide wire slipped in the operating channel; the bronchoscope, but not the wire is withdrawn and the endotracheal tube is inserted over the guide wire.(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Epiglotitis/diagnóstico , Broncoscopía , Preescolar , Sedación Consciente , Epiglotitis/complicaciones , Epiglotitis/terapia , Femenino , Tecnología de Fibra Óptica , Humanos , Lactante , Intubación Intratraqueal/métodos , Masculino , Insuficiencia Respiratoria/etiologíaRESUMEN
A case of pseudo von Willebrand's disease occurring in a 26 year old pregnant woman is reported. The diagnosis was made during the 33rd week of pregnancy. The patient had excessive bleeding of minor wounds, and biological tests revealed a bleeding time exceeding 20 min, a greatly reduced level of Rco fraction of von Willebrand's factor (27%), the absence of high molecular weight von Willebrand's factor multimers, and a greatly increased platelet aggregation in small doses of ristocetin. The patient was allowed to give birth by the vaginal route, receiving 30 IU.kg-1 highly purified concentrated factor VIII, once cervical dilatation was complete. Uterine revision was carried out for safety's sake because of prolonged post-partum bleeding. Two red cell packs were transfused as haemoglobin concentration decreased from 106 g.l-1 to 80 g.l-1. The newborn also presented with biological signs of pseudo von Willebrand's disease, with a bleeding time exceeding 15 min, hypothrombocytopaenia, and a level of Rco fraction of von Willebrand's factor of 9%. Preoperative assessment should always include an investigation of primary haemostatic mechanisms. In case of pseudo von Willebrand's disease, platelet transfusion combined or not with the transfusion of highly purified factor VIII seems to be useful. Investigation of other family members for a pseudo von Willebrand's disease trait is essential.
Asunto(s)
Enfermedades de von Willebrand/sangre , Factor de von Willebrand/análisis , Adulto , Pruebas de Coagulación Sanguínea , Electroforesis en Gel de Agar , Factor VIII/administración & dosificación , Femenino , Hemostasis , Humanos , Recién Nacido , Recuento de Plaquetas , Embarazo , Enfermedades de von Willebrand/genéticaRESUMEN
The shaken baby syndrome is a relatively recent concept concerning mishandled children and characterized by cerebral lesions (subarachnoid haemorrhage, oedema, axonal injuries). A case is reported of a 11-month-old female infant, who was admitted in a paediatric intensive care unit with clinical signs of brain death after cardiopulmonary resuscitation. The CT scan showed subdural haemorrhage. Pathological examination confirmed the major blunt head trauma. The father admitted that he had shaken his daughter as "she cried too often". The mechanism of the lesions is a combination of several factors, especially the large size of infant's head and the weakness of the neck muscles. It is possible to recognize still in the perinatal period children at risk of mishandling, allowing an efficient prevention of the shaken baby syndrome.
Asunto(s)
Síndrome del Niño Maltratado , Hemorragia Subaracnoidea/etiología , Encéfalo/diagnóstico por imagen , Resultado Fatal , Femenino , Humanos , Lactante , Recién Nacido , Recien Nacido Prematuro , Hemorragia Subaracnoidea/diagnóstico , Tomografía Computarizada por Rayos XRESUMEN
OBJECTIVE: To assess the development and the current practice of predeposit autologous blood transfusion (PABT) in children in France. STUDY DESIGN: Nationwide survey with a questionnaire. METHOD: Survey conducted in January 1995, including 121 blood transfusion centres (BTC) out of which 101 replied. RESULTS: Initiated in 1979, PABT is practiced at present in 66% of BTC. This figure increased by 12% from 1993 to 1994. Orthopaedic surgery was the main indication. Other indications included bone marrow harvesting for allogenic transplantation. Concerning the inclusion criteria, the lower limit of age was 9 +/- 4 years and weight 26 +/- 10 kg. The youngest child was one-year-old and his body weight was 8 kg. CONCLUSION: The production of codified protocols would probably favour the development of PABT in children and increase its safety and its efficiency.
Asunto(s)
Transfusión de Sangre Autóloga , Encuestas Epidemiológicas , Adolescente , Factores de Edad , Transfusión de Sangre Autóloga/estadística & datos numéricos , Peso Corporal , Niño , Preescolar , Procedimientos Quirúrgicos Electivos , Humanos , Encuestas y CuestionariosRESUMEN
Due to the action of the drugs and the position of the patient, general anaesthesia in a child with a mediastinal tumor can complete the obstruction of the trachea and/or the main bronchi and possibly result in irreversible respiratory failure. The risk is directly linked to the degree of lumen amputation of the trachea, usually evaluated by CT-scan: there is a risk of accident if the degree of lumen amputation is greater than 30%. The case reports underline the value of the flexible fibreoptic bronchoscopy under local anaesthesia. This examination, as well as the CT-scan, allows to evaluate the degree of tracheal compression. Moreover, it carries a lower risk than the CT-scan which requires, in a small child, either general anaesthesia or heavy premedication which could lead to asphyxia. Total obstruction most often occurs with anterior mediastinal tumors. However, even posterior or lateral tumors can extend to an anterior position, especially in the young child. If the obstruction of the lumen is greater than 30% and if general anaesthesia is required, the fibreoptic bronchoscopy allows endotracheal intubation under local anaesthesia before general anaesthesia. We report 5 cases which illustrate the risk of tracheal compression during general anaesthesia in patients with a mediastinal tumor and substantiate the advantages of a flexible fibreoptic bronchoscope in the management of these patients before and during general anaesthesia.
Asunto(s)
Anestesia General/métodos , Enfermedades del Mediastino/complicaciones , Tráquea/fisiopatología , Anestesia General/efectos adversos , Quiste Broncogénico/complicaciones , Broncoscopía/métodos , Niño , Constricción Patológica , Femenino , Tecnología de Fibra Óptica , Humanos , Lactante , Complicaciones Intraoperatorias , Intubación Intratraqueal/métodos , Linfoma/complicaciones , Masculino , Enfermedades del Mediastino/diagnóstico , Insuficiencia Respiratoria/etiologíaRESUMEN
Known since 1935, the antiarrhythmic effects of magnesium salts are periodically forgotten. They are illustrated here by 4 cases with entirely different clinical and biological features. Of unquestionable therapeutic value was the use of magnesium for the treatment of 2 episodes of severe ventricular extrasystoles with "torsades de pointe". These antiarrhythmic properties are observed whether blood magnesium levels are normal or low and cannot therefore be ascribed to correction of magnesium deficiency. Experimental data are in favour of interferences with transcellular ion flows. Magnesium is thought to ensure normal potassium gradient and also to reactivate the fast sodium channel inhibited by hypokalaemia. Above all, the magnesium ion appears to act as a calcium inhibitor, which would explain its antiarrhythmic properties irrespective of the state of magnesium body stores.
Asunto(s)
Antiarrítmicos/uso terapéutico , Arritmias Cardíacas/tratamiento farmacológico , Magnesio/uso terapéutico , Adulto , Anciano , Electrocardiografía , Humanos , Lactante , Magnesio/metabolismo , Magnesio/farmacología , Taquicardia/tratamiento farmacológicoRESUMEN
OBJECTIVES: To compare the efficacy of aprotinin (APR) and tranexamic acid (TRA) in reducing blood loss and transfusion requirements after cardiac surgery under extracorporeal circulation (ECC). STUDY DESIGN: Randomized controlled trial. PATIENTS: One hundred and four adults undergoing either coronary artery bypass grafting (CABG) (n = 55), or aortic valve replacement (AVR) (n = 49), allocated into three groups. METHODS: a) APR group (23 CABG and 20 AVR) received aprotinin, 2 x 10(6) KIU (280 mg) after induction, followed by an infusion of 0.5 x 106 KIU.h-1 (70 mg.h-1) until chest closure, with a supplement to the oxygenator prime of 2 x 10(6) KIU; b) TRA group (22 CABG and 19 AVR) received tranexamic acid, 15 mg.kg-1 between the injection of heparin (400 IU.kg-1) and the beginning of ECC, 15 mg.kg-1 after protamin injection (1.3 mg/100 IU of heparin); c) CTR group (10 CABG and 10 AVR), the control group, was not treated with an antifibrinolytic agent. The amount of blood collected from the chest tube drainage was measured at admission to ICU, as well as 4, 8 and 18 h after the insertion of drains and at the time of their removal. Packed red cells where given when the haematocrit was under 20% during ECC, 25% at the end of surgery and 30% after extubation. RESULTS: The blood loss was lower in APR group (834 +/- 448 mL) than in TRA group (1015 +/- 409 mL) (P = 0.009), and in CTR group (1416 +/- 559 ML) (P = 0.004). The rates of transfused patients in groups APR, ATR and CTR were 35, 37 and 60% respectively and the numbers of units administered per patient were 0.8, 0.8 and 1.7 respectively. In AVR cases, APR and TRA had a similar efficacy. In CABG cases, only aprotinin decreased postoperative bleeding. However there was no difference between APR and TRA concerning the transfusion requirements. In CABG cases the ECC was of shorter duration and blood loss was 1127 +/- 540 mL vs 894 +/- 422 mL in AVR cases (P = 0.03). CONCLUSIONS: Both APR and TRA decrease blood loss. APR is more efficient after CABG than TRA as far as blood loss is concerned, whereas the transfusion requirements are similar. As APR is about 100 times more expensive and carries a risk for allergic reactions, its use in a high dose regimen is only recommended for reoperations, in patients treated with salicylates and in case of sepsis.
Asunto(s)
Aprotinina/farmacología , Coagulación Sanguínea/efectos de los fármacos , Pérdida de Sangre Quirúrgica , Procedimientos Quirúrgicos Cardíacos , Ácido Tranexámico/farmacología , Adulto , Anciano , Antifibrinolíticos/administración & dosificación , Transfusión Sanguínea , Puente de Arteria Coronaria , Femenino , Prótesis Valvulares Cardíacas , Hematócrito , Hemostáticos/administración & dosificación , Humanos , Periodo Intraoperatorio , Masculino , Persona de Mediana Edad , Periodo PosoperatorioRESUMEN
The authors report 2 cases, in which recurrent and reversible atelectasis of the left lung was the only manifestation leading to a diagnosis of post-traumatic aneurysm of the thoracic aorta at an early stage (D + 5). Other classically described signs were absent. These 2 cases demonstrate the need to seek an aortic aneurysm following any severe trauma. They emphasize the importance of bronchial endoscopy in this type of trauma. They confirm the value of CAT scan investigation.
Asunto(s)
Aneurisma de la Aorta/diagnóstico , Atelectasia Pulmonar/etiología , Adulto , Aorta Torácica/lesiones , Aneurisma de la Aorta/diagnóstico por imagen , Femenino , Humanos , Masculino , Radiografía , Recurrencia , Factores de TiempoRESUMEN
The analgesic efficiency of morphine and propacetamol for postoperative pain, in the recovery room, was studied in two groups of children, who had undergone either orthopedic or visceral surgery. An injection of 50 mcg/kg of morphine chlorhydrate was given to the first group of 239 children ASA I, who were admitted to the recovery room and who presented signs of severe pain (agitation, crying, complaining). The analgesic efficiency of morphine was judged on physiological criteria (blood pressure, heart rate) and on behavioral criteria (calming of the child). No incidents were noticed. A second study was then performed on a second group of 100 children ASA I, who received 15 mg.kg-1 of propacetamol as an intravenous perfusion for 15 minutes. The analgesic efficiency of propacetamol was judged on behavioral criteria alone. In the morphine group, 67% of the children was calmed following one injection (94% after a second injection given 15 minutes after the first). In the propacetamol group, 77% of the children were calmed. Propacetamol was insufficient for the pain in 23% of the cases but one subsequent injection of morphine was always sufficient to calm the child. These two successive studies show the need for an analgesic protocol for children in the recovery room. Propacetamol should be administered first and then, if insufficient, followed by only one injection of morphine. This protocol of propacetamol and morphine seems to be satisfactory and thus avoids all pernicious side effects.
Asunto(s)
Acetaminofén/análogos & derivados , Morfina/uso terapéutico , Dolor Postoperatorio/tratamiento farmacológico , Acetaminofén/administración & dosificación , Acetaminofén/uso terapéutico , Adolescente , Niño , Preescolar , Femenino , Humanos , Lactante , Infusiones Intravenosas , Inyecciones Intravenosas , Masculino , Morfina/administración & dosificación , Sala de RecuperaciónRESUMEN
INTRODUCTION: The Airtraq optical laryngoscope (Vygon, Écouen, France) is a new intubation device designed to provide a view of the glottis without alignment of the oral, pharyngeal and laryngeal axes. In recent literature, the efficiency of the Airtraq even in difficult intubation and its short learning curve were characterized. The goal of our study is to evaluate Airtraq efficiency when use by inexperienced physicians in anticipated difficult intubation adult patients. METHODS: The patients showing at least one of the four difficult intubation predictors (history of difficult intubation, thyromental distance less than 60mm, mouth opening less than 35 mm and Mallampati class 3 or 4 were included. Before induction of anaesthesia, the inexperienced physicians participating the study received a short oral formation on the use of the Airtraq. For each intubation manoeuvres, the participant were supervised by an expert in Airtraq handling. The Cormack and Lehane grade of direct laryngoscopy view, the duration times to best glottis view and to intubate the trachea, the success or failure of tracheal intubation, the drop in arterial oxygen saturation of below 95%, the need for external manipulation, and the difficulties met by the operators were noted. RESULTS: Twenty patients were included over a month period. Thirteen had a history of difficult intubation, eight a thyromental distance less than 60mm, nine a mouth opening less than 35 mm and 12 patients were classified as Mallampati IV. The success rate of tracheal intubation with the Airtraq laryngoscope was 80%. Times to best glottis view and to complete tracheal intubation were 28 and 47 s, respectively. Four tracheal intubation failures were encountered. The LMA Fastrach and the flexible fiberoscope were used respectively in one and three patients. DISCUSSION: In the majority of the cases, the insertion of the Airtraq, the visualization of the glottis and the subsequent intubation were easy and rapid, without arterial oxygen desaturation. However, the four tracheal intubation failures associated with prolonged tracheal intubation times in some patients highlight the fact that the Airtraq laryngoscope requires a clinical training process particularly in case of anticipated difficult airway management situations.
Asunto(s)
Intubación Intratraqueal/instrumentación , Adulto , Anciano , Manejo de la Vía Aérea/métodos , Anestesia por Inhalación , Femenino , Glotis/anatomía & histología , Humanos , Intubación Intratraqueal/métodos , Laringoscopios , Laringoscopía/métodos , Laringe/anatomía & histología , Aprendizaje , Masculino , Persona de Mediana Edad , Fibras Ópticas , Oxígeno/sangre , Respiración ArtificialAsunto(s)
Hipoxia/prevención & control , Enfermedades Pulmonares Obstructivas/tratamiento farmacológico , Piperazinas/uso terapéutico , Almitrina , Humanos , Hipoxia/etiología , Enfermedades Pulmonares Obstructivas/complicaciones , Piperazinas/administración & dosificación , Sueño , Relación Ventilacion-PerfusiónAsunto(s)
Anestesia , Examen Físico , Humanos , Lactante , Cuidados Preoperatorios , Estudios ProspectivosAsunto(s)
Anestesia Raquidea , Bupivacaína , Fentanilo , Adulto , Anciano , Anestesia Raquidea/efectos adversos , Anestesia Raquidea/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Ortopedia , Factores de Tiempo , Enfermedades Urológicas/cirugía , Enfermedades Vasculares/cirugíaAsunto(s)
Polirradiculoneuropatía/inmunología , Toxoplasmosis/complicaciones , Anticuerpos/análisis , Complejo Antígeno-Anticuerpo/análisis , Niño , Complemento C3/análisis , Complemento C4/análisis , Humanos , Inmunoglobulina A/análisis , Inmunoglobulina G/análisis , Inmunoglobulina M/análisis , Cinética , Masculino , Polirradiculoneuropatía/etiología , Toxoplasma/inmunología , Toxoplasmosis/inmunologíaRESUMEN
We studied the efficiency of a heat and moisture exchanging filter (HMEF; Pall BB25) as a means of compensating for the heat and moisture loss during anaesthesia in young children using cold and dry gas supplied from open circuits. Forty ASA I children (mean age: 48 months +/- 20; mean weight: 16 +/- 3.5 kg) were randomized into two groups: Group I without HMEF/Group II with HMEF. The two groups did not show any significant differences for morphometric data or ventilation parameters. Relative humidity and temperature measurements in anaesthetic gases were taken using a combined temperature/humidity probe introduced into the circuit. Absolute humidity in the circuit was calculated from these measurements. In Group II, a significant increase (P < 0.001) in absolute humidity was demonstrated (Group I: 12 mg H2O.1(-1) vs Group II: 22 mg H2O.1(-1). This increase appeared immediately after introduction of the HMEF in the circuit and remained constant throughout the duration of the operation. Thus, the use of the device is recommended for young children, even for operations of short duration.
Asunto(s)
Anestesia por Inhalación/instrumentación , Anestesia por Circuito Cerrado/instrumentación , Anestésicos por Inhalación/administración & dosificación , Anestésicos Intravenosos/administración & dosificación , Temperatura Corporal , Dióxido de Carbono/análisis , Niño , Preescolar , Filtración/instrumentación , Halotano/administración & dosificación , Calor/uso terapéutico , Humanos , Humedad , Intubación Intratraqueal , Isoflurano/administración & dosificación , Propofol/administración & dosificación , Respiración Artificial , Termómetros , Volumen de Ventilación Pulmonar , Factores de Tiempo , Pérdida Insensible de AguaRESUMEN
PURPOSE: We report the use of an ultrathin fibreoptic bronchoscope (Olympus N20: external diameter: 2.2 mm) as the means of airway endoscopic monitoring during anaesthesia for the excision of mediastinal bronchogenic cysts in two young children. CLINICAL FEATURES: The first, a four-month old boy, presented with stridor and wheezing due to a subcarinal bronchogenic cyst compressing the two main bronchi. The second, an eight-day-old girl whose trachea was intubated, presented with respiratory noise in relation to a bronchogenic cyst compressing the end of the trachea. In both cases, airway endoscopy was performed during anaesthesia with the ultra thin fibreoptic bronchoscope. Endoscopic monitoring allowed, first, a good evaluation of the degree of cyst compression on the airways. Second, the endotracheal tube could be positioned or repositioned with precision in order to avoid severe compression or spilling of liquid into the airways and to allow protection of the suture. Finally, video transmission helped the surgeon to visualize the surgical repair from the inside. CONCLUSION: When added to the classical monitoring using SpO2, PETCO2 and airway pressure, peroperative endoscopic control provides complementary information which can help to detect possible complications more rapidly. This technique could be extended to all airway surgery on very young children.
Asunto(s)
Quiste Broncogénico/cirugía , Broncoscopía , Femenino , Tecnología de Fibra Óptica , Humanos , Lactante , Recién Nacido , MasculinoRESUMEN
The present study provides an on-line analysis of diaphragmatic electromyographic activity (EMGdi) in newborns. EMGdi was recorded using surface electrodes. EMGdi signals were processed using a microcomputer (Apple IIe). The centroid frequency (Fc) and the high over low (H/L) frequencies ratio of the power spectrum were calculated. Furthermore the model frequency (Fo) was computed by an autoregressive model of the EMG signal. EMGdi analysis was performed in seven healthy spontaneously breathing preterm newborns. Fc ranged from 46-62 Hz. Fc was significantly lower than Fo in four of the seven preterm newborns. The coefficient of variation for Fc was significantly lower than for the H/L ratio (p less than 0.001). The coefficients of variation for Fo and Fc were not significantly different, but the percentage of rejected calculations for Fo was significantly higher than for Fc (p less than 0.01). Therefore, in healthy preterm newborns, Fc appears to be the best index of EMGdi analysis.
Asunto(s)
Diafragma/fisiología , Recien Nacido Prematuro/fisiología , Procesamiento de Señales Asistido por Computador , Electromiografía/métodos , Humanos , Recién Nacido , MicrocomputadoresRESUMEN
The effect of an intravenous injection of thiopental on middle cerebral artery blood velocities was assessed by transcranial pulsed Doppler monitoring in 20 children: ten head-injured patients and ten control subjects. Thiopental induced a moderate but immediate decrease of middle cerebral artery blood velocities in both groups; this variation was significant (P < 0.01) and more prolonged in the head-injured than in control patients. Transcranial Doppler ultrasonography thus appears to be suitable for monitoring children in intensive care units and could help to avoid the use of thiopental in patients with low cerebral artery blood flow velocity.