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Biomedical subjects

O Paut

Publications and source records attributed to O Paut.

At least 37 records · Page 2Linked to original sources

The effect of low concentrations of halothane on the cerebrovascular circulation in young children.

To determine the effect of halothane on cerebral blood flow velocity measured by transcranial Doppler, 23 healthy young children were studied during surgery. Anaesthesia was induced with thiopental, fentanyl and vecuronium, and maintained with halothane in 70% nitrous oxide in oxygen. A continuous epidural anaesthesia with 0. 25% bupivacaine was performed. End-tidal carbon dioxide pressure, temperature, heart rate and systolic blood pressure were kept constant. Three minimal alveolar concentrations (MAC; 0.5, 1.0 and 1. 5) of halothane were administered in stepwise increases. The cerebral blood flow velocity increased significantly at 1.0 (p < 0. 01) and 1.5 MAC (p < 0.001) compared with the value at 0.5 MAC. No further change in cerebral blood flow velocity was seen between 1.0 and 1.5 MAC. These data show that maximal changes in cerebral blood flow velocity are obtained at 1.0 MAC and that further increases in halothane concentration do not modify the cerebral circulation. It is suggested that young children differ from adults in that the maximal effect of halothane occurs at lower concentrations.

Anesthetics, Inhalation↗

Pharmacokinetics of transdermal fentanyl in the peri-operative period in young children.

The pharmacokinetics of transdermal fentanyl were assessed in eight children aged 18-60 months, weighing 11-20 kg and monitored postoperatively in the intensive care unit. A patch, delivering 25 microg.h-1 of fentanyl, was applied for 72 h from the induction of anaesthesia. Plasma fentanyl concentrations were measured over 144 h. Mean (SD) peak concentration of fentanyl was 1.7 (0.66) ng.ml-1 and time to reach maximal plasma concentration was 18 (11) h. The elimination half-life was 14.5 (6.2) h, and the area under the curve for plasma fentanyl concentration (0-144 h) was 86.8 (27) ng.h.ml-1. Maximal fentanyl concentration was negatively correlated with patient age (r = - 0.71; p = 0.049) but not with body weight. These results suggest that the pharmacokinetics of transdermal fentanyl in children are similar to those in adults.

Administration, Cutaneous↗

[Causes of preoperative mortality in transposition of great vessels. 2 cases].

The prognosis of transposition of the great arteries improved tremendously with the development of an early medico-surgical strategy including balloon atrioseptostomy, prostaglandin infusion and the arterial switch operation within the first days of life. Nevertheless, some patients still die preoperatively. We report on two newborn infants whose fatal outcome was promoted by an inadequate intercirculatory mixing. Since the diagnosis was not immediately made, the restrictive foramen ovale resulted very quickly in deep metabolic acidosis and balloon atrioseptostomy performed yet in the first hours of life could not prevent death. We emphasize the importance of prenatal echographic detection of this defect, only way to plan a balloon septostomy immediately after delivery in those infants suffering from inadequate atrial mixing.

Acidosis↗

[Severe lactic acidosis and thiamine deficiency during parenteral nutrition in a child].

We report the case of a leukemic child treated with chemotherapy and parenteral nutrition for three weeks, who developed a severe lactic acidosis. Clinical features included both digestive and neurological disorders associated with a moderate cardiovascular collapse. After elimination of a toxic, a neoplastic or a septic cause, a thiamin (or vitamin B1) deficiency was suspected because of the lack of vitamin supply to parenteral nutrition. Intravenous administration of thiamin rapidly controlled lactic and clinical features. The diagnosis was confirmed by a low plasmatic concentration of thiamin. Thiamin deficiency must be suspected in case of severe lactic acidosis during parenteral nutrition and systematically prevented by supply of vitamins.

Acidosis, Lactic↗

The management of extreme hypernatraemia secondary to salt poisoning in an infant.

We describe a five-week-old boy who had seizures and extreme hypernatraemia secondary to ingesting an improper home-made formula. Initial sodium concentration was 211 mmol.l-1. Other clinical and biological features were moderate dehydration and renal insufficiency with generous urine output and high urinary sodium concentration. Fluid therapy with hypotonic dextrose solution corrected the volume deficit in 48 h and progressively decreased the serum sodium concentration. During ICU stay the patient developed recurrent episodes of seizures and pulmonary oedema requiring mechanical ventilation for five days. Recovery was complete with no abnormal sequelae after a ten-month follow-up. Salt poisoning is in unusual cause of extreme hypernatraemia. It can be safely managed with fluid therapy alone if urine output is preserved, with progressive decrease of serum sodium as target. If this condition is recognized, outcome should be favourable.

Fluid Therapy↗

[Severe potassium dichromate poisoning after accidental nasal introduction].

BACKGROUND: Nasal foreign body (NFB) is a common situation in pediatrics. Poisoning is a rare complication of NFB insertion. We report a case of acute potassium dichromate poisoning secondary to NFB insertion. CASE REPORT: Six days after insertion of a NFB, progressive occurrence of diarrhea, vomiting, nasal obstruction, acute renal failure, pancreatitis, hepatitis and drowsiness justified hospitalization of a 3-year-old girl in the pediatric intensive care unit. Acute potassium dichromate poisoning was confirmed by high plasma chromium level and by the spectrophotometric analysis of the crystal. Recovery was satisfactory with supportive treatment. An official survey allowed to discover that the crystal was freely sold and that its toxicity was unknown by dealers, while no information was given to the customers. CONCLUSION: Transmucosal absorption of toxics is an unusual severe potential hazard that should be evoked to allow a rapid management. After the discovery and withdrawal of a NFB, occurrence of systemic symptoms, even trivial, must make one suspect a poisoning. In this circumstance, analysis of the foreign body should be done, associated with toxicologic dosages. This case report illustrates that potassium dichromate poisoning is a severe medical condition and that its clinical presentation assume a large widespread of symptoms due to multiple organ involvement.

Absorption↗

[Recent developments in the treatment of pediatric acute respiratory distress syndrome].

Acute respiratory distress syndrome (ARDS) is a severe condition with a high mortality rate, despite conventional treatment using mechanical ventilation. Better understanding of the pathophysiology and awareness of important iatrogenic lung injury secondary to mechanical ventilation has led to new therapeutic principles. Mechanical ventilation strategy during ARDS is characterized by positive end-expiratory pressure, increase in the inspiratory time, high inspiratory oxygen concentration and, more recently, use of permissive hypercapnia. High frequency ventilation allows optimal lung recruitment under small tidal volume. The effectiveness of extracorporeal oxygenation techniques is demonstrated, but because of their cost and morbidity these therapies are rational only in patients who seem likely to die. Partial liquid ventilation and inhaled nitric oxide have great potential but require further studies. Intratracheal exogenous surfactant might be beneficial but controlled trials are needed to confirm the usefulness of this expensive therapy. Finally, a number of adjuncts to mechanical ventilation are currently available to minimize iatrogenic lung injury and improve the outcome. The role of these new treatments must be defined with randomized and controlled clinical trials using homogenous inclusion criteria.

Child↗

[Severe trauma in children].

Trauma are responsible for approximately 50% of the deaths of the pediatric population between 1-15 years of age. This high mortality rate, associated with frequent sequelae, leading sometimes to severe handicaps, is a major problem of public health in the developed countries. Pediatric trauma have some particularities, due to anatomical and physiological differences, and to specific injury mechanisms. Management of a patient with severe trauma is best performed by trained physicians, working in a multidisciplinary team with a two steps approach: 1) emergency rapid clinical assessment and resuscitation. 2) a secondary complete clinical evaluation associated with medical imaging, mainly based on CT scan. Head injuries are frequent and represent the main prognosis factor, mass lesions being less frequent and cerebral oedema more frequent in children, than in adult; brain swelling appears to be less frequent than initially reported. Management of head trauma has evolved in recent years, and is now largely directed towards the prevention of secondary ischemic brain injury: new monitoring devices are proposed to pursue that goal: transcranial doppler and continuous jugular vein oxygen saturation monitoring. Spinal cord injuries are rare but may be severe: cervical and spinal cord injuries without radiological abnormality (SC/WORA) appear to be more frequent than in adult. Most often, abdominal plain viscera injuries are treated with a conservative non operative approach. Among chest injuries, pulmonary contusion is the most frequent, with a favorable outcome in most cases within 3-4 days. Child abuse must be suspected in any case where there is no clear injury mechanism or when there is a discrepancy between the severity of the injury and the alleged mechanism.

Adolescent↗

Acute presentation of congenital diaphragmatic hernia past the neonatal period: a life threatening emergency.

PURPOSE: Major gastric distension in the left hemithorax can threaten life in patients with congenital diaphragmatic hernia (CDH) presenting after the neonatal period. After presentation of two pediatric cases, guidelines for the optimal care of these patients are given. CLINICAL FEATURES: Both children had respiratory and cardio-circulatory compromise on arrival. The diagnosis of late presenting CDH was made and the severity of symptoms was related to a voluminous distension of an intrathoracic stomach. Successful placement of an naso-gastric tube in the first patient, lead to a rapid clinical improvement, allowing surgical repair. In the second patient, oro- or naso-gastric decompression was not possible, and while the lungs were mechanically ventilated and the patient was prepared for surgery, a sudden cardiocirculatory arrest was managed by external chest compressions and rescuscitation drugs. Transthoracic percutaneous decompression of the stomach was the sole treatment allowing spontaneous cardiac activity to reappear, and haemodynamic condition to normalize. However, the child died from brain death after this episode. CONCLUSION: Gastric decompression is the key for the treatment of patients with CDH who present respiratory and/or cardiocirculatory distress due to the intrathoracic distension of the stomach. If an oro- or naso-gastric decompression is not possible, then radiologically directed percutaneous decompression under local anesthesia is required. After decompression, the patient is prepared for surgery, with particular emphasis on fluids infusion, in order to correct the frequently associated hypovolaemia.

Acute Disease↗

[Value of surfactant in the treatment of acute respiratory distress syndrome in a child].

BACKGROUND: Adult respiratory distress syndrome has a high mortality rate, despite treatment including mechanical ventilation with positive end-expiratory pressure, increase of the inspiratory time and high inspiratory oxygen concentration. Exogenous surfactant, a well established treatment in premature newborns with neonatal respiratory distress syndrome has only been occasionally evaluated in adult respiratory distress syndrome. CASE REPORT: A 3 year-old child suffered from adult respiratory distress secondary to respiratory syncytial virus infection. Both mechanical ventilation and inhaled nitric oxide failed to improve the respiratory distress. Two doses of intratracheal surfactant application immediately improved pulmonary functions, transiently after the first instillation on day 13 and definitely after the second one, on day 16. CONCLUSION: Exogenous surfactant appeared to be useful for the survival of our patient but prospective evaluation of this treatment in adult respiratory distress syndrome is needed.

Acute Disease↗

[Perioperative fasting in children: current data].

Perioperative fasting aims at decreasing the incidence of gastric content inhalation during anesthesia. Current knowledge concerning gastric emptying and the epidemiology of pulmonary aspiration authorizes new perioperative fasting guidelines. If prolonged fasting does not guarantee gastric emptiness at the induction of anesthesia, shortening preoperative fasting by allowing clear fluids two hours before surgery does not modify gastric content and does not increase the risk of gastric content aspiration, while enhancing the patient comfort by reduction of the fasting period. On the other hand, after surgery, the mandatory intake of water significantly increases the incidence of postoperative vomiting. Therefore new guidelines may be applied for children operated in ambulatory surgery settings: 1) clear fluids may be allowed until 2-3 hours before operation, 10 ml.kg-1, or even ad libitum for some authors (by clear fluids one means water, tea, coffee, apple juice, syrup with water); 2) drinking is not absolutely necessary before discharge from day care surgery unit and should be left to the child's own assessment.

Child↗

Evaluation of saccadic eye movements as an objective test of recovery from anaesthesia.

Saccadic eye movements have been previously used to assess residual effect of anaesthetics, but this test is seldom compared to other psychomotor tests. The aim of the present study was to validate saccades as a recovery index in relation to frequently referred subjective and psychometric tests. Eight healthy subjects were tested before and after intra-muscular injection of either placebo or 0.15 mg.kg-1 of midazolam. Each session consisted of a saccadic test (recorded by electro-oculography), a choice-reaction-time test (CRT), a subjective state-of-alertness test (11 visual analogic scales) and blood sampling (to monitor midazolam plasma concentration), before and 30 (t30), 60 (t60), 120 (t120), 180 (t180), 240 (t240) minutes after drug administration. In the placebo group, there was no change in subjective assessment, saccade characteristics (latency, peak velocity and duration) or CRT results. In the midazolam group, 6 subjective items changed with different time-courses, when compared to baseline: from t30 to t120 (drowsy, in shape, tired, clumsy, strong) and t120 (woolly). Saccade latency and duration were significantly different from t30 to t120 and until t180 for peak velocity. CRT performance was significantly altered from t30 to t120. Midazolam plasma concentration decreased from 177 +/- 33 ng.ml-1 at t30 to 47 +/- 12 ng.ml-1 at t240. At this latter time, sensorimotor functions returned to the baseline. All subjects fulfilled the clinical conditions for home discharge 4 hours after administration. These results suggest that a saccadic eye movement test is a sensitive and reliable tool for the assessment of residual effect of anaesthetics. This test was found to be more sensitive than CRT test since peak saccadic velocity was the last psychometric parameter to be returned to baseline after midazolam injection. This study also confirms the poor reliability of subjective assessment, as subjects tended to underestimate the alteration of their performance immediately following drug injection.

Adult↗