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Biomedical subjects

J López-Herce

Publications and source records attributed to J López-Herce.

At least 19 recordsLinked to original sources

[Middle latency auditory evoked potentials in critical care children: preliminary study].

BACKGROUND: Middle latency auditory evoked potentials (MLAEP) reflect changes in electroencephalogram waves after an auditory signal and represent the earliest cortical response to acoustic stimulus. They are therefore used to measure variations in the level of consciousness. MLEAP have been used to measure the depth of anesthesia during surgical procedures, but experience in critical care patients is very limited. OBJECTIVE: To analyze the utility of MLAEP for monitoring the level of sedation in critically ill children. METHODS: Level of consciousness was monitored through MLAEP by placing special headphones and three sensors situated in the frontal and preauricular regions. Simultaneously, the level of sedation was measured using the COMFORT scale and the Bispectral Index (BIS) in distinct clinical situations. RESULTS: We studied six critically ill children in whom MLAEP helped us to evaluate the level of consciousness: light sedation, natural sleep, deep sedation, sedation in a paralyzed child, and brain death. MLAEP showed a good correlation with the COMFORT scale and BIS in light and deep sedation and were effective in the early detection of brain death in one patient. In the paralyzed patient, MLAEP was able to detect undersedation. In one patient, a pacemaker interfered with the MLAEP signal. CONCLUSIONS: MLAEP can be useful in evaluating the level of consciousness and sedation in critically ill children. Further studies with larger samples are required to analyze the limitations and reproducibility of this type of monitoring in children of different ages.

Brain Death↗

Comparison between cardiac output measured by the pulmonary arterial thermodilution technique and that measured by the femoral arterial thermodilution technique in a pediatric animal model.

This study compares the correlation between two methods for the determination of cardiac output-the pulmonary arterial thermodilution technique using the Swan-Ganz catheter and the femoral arterial thermodilution technique using a pulse contour analysis computer (PiCCO) catheter. We performed a prospective animal study using 16 immature Maryland pigs weighing 9 to 16 kg. A 5.5- or 7.5-Fr Swan-Ganz catheter was introduced into the femoral or jugular vein, and a 4- or 5-Fr arterial PiCCO catheter was introduced into the femoral artery. In each animal, we made measurements of cardiac output at 30-minute intervals, simultaneously by pulmonary arterial thermodilution and femoral arterial thermodilution, before, during, and after hemodiafiltration carried out via different venous catheters, recording a total of 78 measurements. The mean Swan-Ganz cardiac output was 2.22 +/- 0.94 L/min, and mean PiCCO cardiac output was 1.94 +/- 0.80 L/min (no significant difference). The mean difference (bias) of differences (limits of agreement) was 0.2812. The differences between the methods increased with higher cardiac output, but the percentage differences in relation to cardiac output remained stable. Good correlation was found between the two methods: single-measure intraclass correlation was 0.8892 (95% confidence interval, 0.54-0.95). There were no differences between the 5.5- and 7.5-FR Swan-Ganz catheters or between the 4- and 5-Fr PiCCO catheters. Femoral arterial thermodilution cardiac output measurements correlated well with pulmonary arterial thermodilution cardiac output measurements in a pediatric animal model.

Animals↗

[Mechanical ventilation in pediatrics (III). Weaning, complications and other types of ventilation. Compications of mechanical ventilation].

Mechanical ventilation can produce multiple complications. The most important acute complications are mechanical problems (respirator failure, problems with the connections and circuit, incorrect parameters or alarms), problems in the airway (disconnection, extubation, mal-positioning of the endotracheal tube, leaks, nose erosions, obstruction of the endotracheal tube due to secretions or kinking, mainstem bronchus intubation, bronchospasm, postextubation croup), pulmonary complications (ventilator-induced lung injury with barotrauma, volutrauma and biotrauma), hemodynamic complications, nosocomial infections (tracheobronchitis, pneumonia, otitis, sinusitis), failure of adjustment of the respirator to the patient, and nutritional complications. The most important chronic problems are subglottal stenosis, chronic pulmonary injury, and psychological alterations.

Barotrauma↗

Hepatic dysfunction after cardiac surgery in children.

OBJECTIVE: The objective of this study was to analyze the incidence and significance of hepatic dysfunction after cardiac surgery in children. DESIGN: Prospective, observational study. SETTING: Pediatric intensive care unit of a university hospital. PATIENTS: The study consisted of 232 children ranging in age from newborn to 17 years with no history of liver disease. MEASUREMENTS AND MAIN RESULTS: Aspartate aminotransferase (AST), alanine aminotransferase (ALT), gammaglutamyltranspeptidase (GGT), alkaline phosphatase, total and conjugated bilirubin, blood glucose, urea, creatinine, and coagulation studies were determined at admission, at 24 and 48 hrs, and at 7 days. Hepatic dysfunction was taken as an ALT of > 100 IU/L or a moderate or high hepatic score. The statistical study included bivariate analysis and multivariate logistic regression to study the risk factors for hepatic dysfunction. Twenty-one patients (9%) showed an ALT > 100 IU/L, and 29.3% had a moderate or high hepatic score. A relationship was found between hepatic dysfunction and the type of cardiopathy (D-transposition of the great arteries and coarctation of the aorta), shock, the administration of dopamine or epinephrine, renal insufficiency, the presence of pulmonary changes (pulmonary edema, atelectasis, pulmonary hypertension, hypoxemia), hematologic disturbances (prothrombin time, kaolin-cephalin time, fibrinogen, and platelets), and the need for a greater number of transfusions of packed cells, plasma, and platelets. Compared with 7.6% of the rest of the patients (p <.001), 38% of patients with an ALT > 100 IU/L died. The hepatic score of those patients who died was 4.2 (2.3)-higher than that of the survivors at 1.5 (1.8), (p <.001). Shock and renal insufficiency were the factors most significantly related to the development of hepatic dysfunction. CONCLUSIONS: Hepatic dysfunction is an uncommon complication in children after cardiac surgery. This complication is related mainly to hemodynamic disturbances and renal insufficiency and is an indicator of poor prognosis.

Journal Article↗

Study of paediatric intensive care units in Spain. Spanish Society of Paediatric Intensive Care.

OBJECTIVE: To describe the organisation of paediatric intensive care units in Spain and the medical assistance provided during 1996. METHODS: A written questionnaire was sent to all the paediatric ICUs linked to or within the Spanish public health system. RESULTS: Thirty-one of the 34 paediatric ICUs replied. All are medico-surgical units. Eighteen treat only paediatric patients, 12 paediatric and neonatal patients, and one paediatric and adult patients. Fifteen units have fewer than seven beds, eight have between 7 and 12 beds, and eight between 13 and 18 beds. Of the paediatric ICUs, 83.8 % are staffed by paediatricians specialised in paediatric intensive care. The mean number of on-call on site periods of duty for each member of the medical staff was 5.1 +/- 1.7 per month. Thirty of the 31 units undertake paediatric resident training, 13 train residents specialising in paediatric intensive care and 12 participate in medical student training. In 1996 there were 9,585 admissions (309 +/- 182 patients per ICU) signifying 35.3 +/- 14 patients/bed. Of the patients, 65.9 % were medical and 34.1 % surgical. The mean duration of stay was 5.6 +/- 2.1 days. The mortality rate was 5.4 +/- 3.2 %. The main causes of death were multiple organ failure and brain death. CONCLUSIONS: In Spain, paediatric intensive care is principally performed by specialised paediatricians. Although the general results for 1996 are similar to those of other European countries, efficiency studies are necessary to plan and re-organise the paediatric intensive care units in Spain.

Adolescent↗

Transpyloric enteral nutrition reduces the complication rate and cost in the critically ill child.

BACKGROUND: Studies in adults have shown that transpyloric enteral nutrition (TEN) is useful in certain patients who cannot tolerate oral or gastric feeding. This study was conducted to compare TEN with parenteral nutrition (PN) in critically ill pediatric patients. METHODS: A retrospective descriptive study conducted in the pediatric intensive care unit of a tertiary pediatric referral center. All patients in the pediatric intensive care unit (PICU) receiving PN and/or TEN from January 1993 through December 1996 were included in the study. RESULTS: Two hundred forty patients (14.6% of all patients admitted to the PICU) received PN and/or TEN (168 exclusively PN, 21 exclusively TEN, and 51 a combined regimen). The number of patients receiving PN and duration of PN declined significantly from 1993 (65 patients, 703 days) through 1996 (48 patients, 395 days). This was mirrored by the increase in the number of patients receiving TEN and duration of TEN. The incidence of complications (hyperglycemia, hypertriglyceridemia, and cholestasis) was higher in the PN group. There was no difference in the incidence of hospital-acquired infection or mortality between the two groups. The cost of TEN was lower than that of PN, with an estimated annual saving of $5,422. CONCLUSIONS: Transpyloric enteral nutrition is a suitable method of nutritional support for critically ill pediatric patients. It has fewer complications and a lower cost than PN.

Child↗

Normal values for serum, ultrafilterable and intraerythrocytic magnesium in children.

Serum magnesium (MgS), levels were determined in 137 children age range 2 months to 16 years. Ultrafilterable magnesium (MgU) and intraerythrocytic magnesium (MgI) concentrations were determined in 37 of these children. MgS was 0.83 +/- 0.1 mmol/L (range 0.66-1.36 mmol/L), with no differences between sexes. Children under 2 years had higher MgS levels (0.92 +/- 0.13 mmol/L) than children over 2 years (0.81 +/- 0.08 mmol/L; p < .001). Mean MgU was 0.60 +/- 0.07 mmol/L (range 0.50-0.87 mmol/L), with no differences between sexes. Mean MgI in children was 2.58 +/- 0.33 mmol/L (range 2.06-3.6 mmol/L), with no differences between sexes. MgS correlated with MgU, age, theoretical growth rate, and serum calcium, phosphorus and alkaline phosphatase; MgU correlated with MgI, age, theoretical growth rate, and serum phosphorus. MgS concentration was higher in children under 2 years than in children over 2 years. In healthy children, MgS concentration correlated with MgU, and MgU correlated with MgI, but MgS and MgI showed no correlation.

Adolescent↗

Teicoplanin pharmacokinetics in critically ill paediatric patients.

Twenty-one critically ill children aged between 7 days and 12 years were treated with teicoplanin (three loading dosages of 10 mg/kg at 12 h intervals, followed by a maintenance dosage of 10 mg/kg/day). Serum teicoplanin concentrations were monitored by HPLC. Mean concentrations in plasma 30 min after drug administration were 20 +/- 16.1 mg/L. The volume of distribution was 0.30 L/kg and the terminal half-life was 17.41 h. Only 11% of trough values were >10 mg/L (established as desirable values). In critically ill children a dosage of 10 mg/kg/day does not assure serum trough values >10 mg/L.

Anti-Bacterial Agents↗

Surfactant treatment for acute respiratory distress syndrome.

OBJECTIVE: To determine prospectively the efficacy of surfactant in acute respiratory distress syndrome. STUDY DESIGN: Twenty patients, 1 month to 16 years of age, diagnosed with an acute pulmonary disease with severe hypoxaemia (PaO2/FiO2 < 100) (13 with systemic or pulmonary disease and seven with cardiac disease) were treated with one to six doses of 50-200 mg/kg of porcine surfactant administered directly into the trachea. The surfactant was considered to be effective when the PaO2/FiO2 improved by > 20%. RESULTS: After initial surfactant administration the PaO2/FiO2 increased significantly in patients with systemic or pulmonary disease from 68 to 111, and the oxygenation index (OI) diminished significantly from 36.9 to 27.1. The PaO2/FiO2 and OI did not improve in children with cardiac disease. The improvement of the patients who survived was greater than that of those who died. CONCLUSIONS: Surfactant moderately improves oxygenation in some children with severe acute respiratory distress syndrome secondary to pulmonary or systemic disease.

Adolescent↗

Paediatric life support instructors courses in Spain. Spanish Paediatric and Neonatal Resuscitation Group.

Between October 1996 and February 1998 we have provided five PLS instructors courses for 127 physicians. The instructor course takes 20-24 h over in 3 days, with 20-36 students per course. Theory classes last 5 h and practical stations between 14 and 18 h. Theory classes include: types and organisation of paediatric courses, resuscitation material, methodology of education, didactic methods, and methods of evaluation. The practical classes include techniques of oral expression, resuscitation material, and methodology, and evaluation of basic life support, airway and ventilation, venous and intraosseous access, diagnosis and treatment of arrythmias, neonatal resuscitation and advanced resuscitation. At the end of the course the students perform an anonymous written evaluation of the course with scores between 1 (very bad), 2, 3, 4 and 5 (very good). Theoretical aspects practical classes, methodology, and organisation of the PLS instructors courses are considered satisfactory by the students. We conclude that PLS instructors courses are important for assuring the uniformity and quality of paediatric life support courses.

Cardiopulmonary Resuscitation↗

Reference values of gastric intramucosal pH in children.

To determine the reference values of gastric intramucosal pH (pHi) by tonometry in paediatric patients, we studied 17 children (nine males, eight females) with no systemic or gastrointestinal disease, aged six months to 12 years undergoing minor reconstructive surgery. Following anaesthetic induction a sigmoid tonometry catheter was inserted (Tonometrics, Inc.) into the stomach of the patients under direct vision. All children were normoventilated and were haemodynamically stable. After an equilibration period of 30 min, gastric pHi was calculated by applying the Henderson-Hasselbalch equation on the PCO2 obtained with the tonometer and the bicarbonate from the arterial blood gas analysis. The mean gastric pHi in our patients was 7.35 +/- 0.06 (SD). The normal pHi in the general population is estimated to be 7.31-7.40, with a confidence interval of 99%. No correlation was found between pHi and arterial pH, bicarbonate or base excess. Under conditions of normal ventilation and haemodynamic stability, healthy children during general anaesthesia have gastric intramucosal values similar to those of adults.

Blood Chemical Analysis↗

Transpyloric enteral feeding in critically ill children.

BACKGROUND: Nutrition is important in childhood because the child has a lower energy reserve than the adult and a higher demand for calories because of ongoing growth. In this study, the utility of transpyloric enteral feeding (TEF) in critically ill children was evaluated. METHODS: A prospective, descriptive study was made in a pediatric intensive care unit of a tertiary pediatric center of 41 critically ill children, 30 after surgical procedures and 11 with nonsurgical illness, aged 8 days to 12 years, who received transpyloric enteral feeding with 8- or 10-Fr weighted feeding tubes. Analysis was made of tolerance and complications (vomiting, abdominal distension, excessive gastric residual, diarrhea, and pulmonary aspiration) of TEF. RESULTS: The mean duration of TEF was 19.5 +/- 26.8 days (range, 1-120 days). The administration of sedative agents or inotropic drugs did not alter toleration of TEF. Eight of 12 patients treated with continuous infusion of vecuronium tolerated TEF without complications. Eleven gastrointestinal complications occurred in 10 patients, abdominal distension and excessive gastric residual in 7 (17%), and diarrhea in 4 (9.7%). In 7 patients gastrointestinal complications improved, with decreasing use or transitory interruption of TEF, but in 4 patients (9.7%), TEF had to be withdrawn. Gastrointestinal complications were more frequent in postsurgical than in nonsurgical patients (p < 0.001). No patients suffered from pulmonary aspiration, and the incidence of pulmonary infection and hepatic dysfunction diminished during TEF. CONCLUSIONS: Transpyloric enteral feeding is a good method of nutritional support in critically ill children and can be used in patients treated with neuromuscular blocking agents. The frequency and severity of complications and the risks of pulmonary infection and hepatic dysfunction related to TEF are low.

Child↗

[Carboxyhemoglobin levels and risk factors of carbon monoxide poisoning in children;].

BACKGROUND: To determine carboxyhemoglobin levels and to investigate carbon monoxide poisoning risk in children. PATIENTS AND METHODS: We determine carboxyhemoglobin blood levels by cooximetry in 65 children, between 15 days and 15 years attended in a pediatric emergency section. We analyze carbon monoxide risk factors (type of heating and smokers in the family). RESULTS: Mean carboxyhemoglobin levels in 59 children without acute intoxication was 0.5 +/- 0.87% (range 0-3.8%). There are no significant differences with respect to age and sex. Children with wood or coal heating (0.88 +/- 1.34%) and gas heating (0.58 +/- 0.97%) have carboxyhemoglobin levels higher than children with electric heating (0.28 +/- 0.4%) but differences were no statistically significant. Four patients have carboxyhemoglobin levels > 2%, two with coal or wood hating and two with gas heating. Children with smokers in the family have carboxyhemoglobin levels higher than the rest of children (0.65 +/- 1.05% versus 0.34 +/- 0.45%) without statistical significance. The four children with carboxyhemoglobin levels > 2% live with smokers. Six children suffered carbon monoxide poisoning with carboxyhemoglobin levels between 20.6 and 36.6%. CONCLUSIONS: Mean carboxyhemoglobin levels in children are low. There are carbon monoxide poisoning risk factors (wood, coal or gas heating at home, and smokers in the family) in a high percentage of the children, although they did not show statistical significance.

Adolescent↗

Bronchoesophageal fistula secondary to aspiration of tongue adhesion button in a child with glossoptosis.

A newborn boy with obstructive apnea secondary to glossoptosis was treated by securing his tongue to his lower lip. Soon after, the button that served for posterior fixation became detached and was thought to have been evacuated via the digestive tract. Twenty-two months later the infant presented with pneumonia involving the right lower lobe and hemoptysis, causing an acute respiratory distress syndrome (ARDS). After mechanical ventilation was started marked gastric distention was observed. Esophagography and bronchography revealed a fistula between the right main stem bronchus and the esophagus. During surgical repair the plastic fixation button was found in the bronchial orifice of the fistula. Despite surgical correction of the fistula the child died of refractory respiratory failure.

Bronchi↗

Usefulness of gastric intramucosal pH for monitoring hemodynamic complications in critically ill children.

OBJECTIVE: To assess the efficacy of gastric intramucosal pH for the evaluation of tissue perfusion and prediction of hemodynamic complications in critically ill children. DESIGN: Open prospective study without controls. SETTING: Pediatric intensive care unit (ICU) of a tertiary care university pediatric hospital. PATIENTS: Thirty critically ill children (16 boys and 14 girls), age range: 3 months-12 years. MEASUREMENTS AND RESULTS: A tonometry catheter was placed in the stomach of all patients on admission to the pediatric ICU. Simultaneous tonometry and arterial gas measurements were made on admittance and every 6-12 h throughout the study; a total of 202 measurements were made. The catheter was removed after extubation and/or when the patient was hemodynamically stable. Intramucosal pH was calculated using the Henderson-Hasselbalch equation based on the pCO2 of the tonometer and arterial bicarbonate. Intramucosal pH values between 7.30 and 7.45 were considered to be normal. The patient's condition was analyzed using the Pediatric Risk Mortality Score (PRISM). The relations between intramucosal pH and the presence of major hemodynamic complications (cardiopulmonary arrest, shock), minor hemodynamic complications (hypotension, hypovolemia or arrhythmia), death, PRISM score and the duration of the stay in the pediatric ICU were analyzed. Intramucosal pH on admission was 7.48 +/- 0.15 on average (range 7.04-7.68). Five patients (16%) had an intramucosal pH lower than 7.30 on admission; these patients did not have a higher incidence of hemodynamic complications. The 16 patients (53%) who had an intramucosal pH of less than 7.30 at some time during the course of their disease had more hemodynamic complications than the patients who did not have pH lower than 7.30 (p < 0.0001). Every case of cardiopulmonary arrest and shock was related to intramucosal pH of less than 7.30. Patients with major complications (cardiopulmonary arrest and shock) had lower intramucosal pHs than those with minor hemodynamic complications (p = 0.03); similarly, they had low intramucosal pH readings more often than those with minor complications (p = 0.0032). Intramucosal pH values less than 7.30 had a sensitivity of 90% and a specificity of 98% as a predictor of hemodynamic complications. There was no relation between intramucosal pH lower than 7.30 and either PRISM or the duration of the stay in the pediatric ICU. Patients with intramucosal pH less than 7.20 had a higher PRISM than the patients who did not have pH lower than 7.20 (p < 0.05). A patient who died during the study due to cardiopulmonary arrest had prior intramucosal pH measurements of 7.23 and 7.10, and three patients died of late complications after the end of the study. Hemodynamic complications were not detected with arterial pH. Gap pH (arterial pH-intramucosal pH) and standard pH measurements yielded the same results as gastric intramucosal pH. CONCLUSION: Intramucosal pH could provide a useful early indication of hemodynamic complications in critically ill children.

Acid-Base Equilibrium↗