Administración intrarterial de un magnetofluido termoterapéutico en un modelo experimental de metástasis hepáticas. Estudio de distribución con resonancia magnética y espectrometría / Magnetic resonance imaging and spectrometric study of the distribution of thermotherapeutic magnetofluid after intra-arterial administration in an experimental model of liver metastases

Objetivo. Valorar la distribución vascular de un magnetofluido por técnicas de imagen y laboratorio, en un modelo de metástasis hepáticas. Material y métodos. El hígado de 33 ratas WAG/RijCrl fue diseminado con células de carcinoma colorrectal CC-531. Tras comprobar desarrollo tumoral, diez ratas recibieron infusiones intrarteriales hepáticas de Lipiodol® con nanopartículas de Fe3O4 en suspensión, y cinco se reservaron como controles. Posteriormente, en RM de 1,5 T se practicaron secuencias axiales STIR (TR: 3.600ms/TE: 29ms/TI: 130ms) y eco de gradiente (EG) (120/4 y 120/14). Tras necropsia, según desarrollo tumoral, las ratas se clasificaron en dos estadios: precoz (< 10 metástasis, de < 3mm), avanzado (> 10 metástasis, de>3mm). De los 15 animales se tomaron muestras de hígado y metástasis, para cuantificar mediante espectrometría (ICP-MS) las concentraciones de hierro. En el análisis estadístico se emplearon pruebas no paramétricas. Se consideraron significativos valores de p < 0,05. Resultados. Cinco animales presentaron afectación precoz y cinco, avanzada. En secuencias EG, las metástasis en estadio precoz mostraron disminución homogénea de señal atribuible a presencia de magnetofluido. La espectrometría demostró diferencias significativas entre la concentración de hierro determinado en metástasis de ratas en estadio precoz y control (p=0,002), y entre animales en estadio precoz y avanzado (p=0,001). La razón entre hierro exógeno metastásico y hepático en ratas en estadio precoz fue 2,6:1. La concentración de hierro exógeno hepático y tumoral mostró diferencias significativas sólo en animales en estadio precoz (p=0,043). Conclusiones. RM y Espectrometría permitieron evaluar la distribución vascular hepática del magnetofluido, y revelaron su desigual afinidad por metástasis en diferentes estadios (AU)

Objective. To use imaging and laboratory techniques to evaluate the vascular distribution of magnetofluid in a rat model of liver metastases. Material and methods. The livers of 33 WAG/Rij Crl rats were seeded with CC-531 colorectal cancer cells. After we checked tumor development, 10 rats received hepatic intra-arterial infusions of Lipiodol® with nanoparticles of Fe3O4 in suspension, and 5 were reserved as controls. Axial STIR (TR: 3,600ms/TE: 29ms/TI: 130ms) and gradient-echo (GE) (120/4 and 120/14) MRI sequences were acquired on a 1.5 T scanner. After necropsy, rats were classified into one of two stages according to tumor development: early (< 10 metastases, each < 3mm) or advanced (> 10 metastases, each > 3mm). Samples of liver and of metastases were taken from the 15 animals for quantification of iron concentrations by inductively coupled plasma mass spectrometry (ICP-MS). The data were analyzed using nonparametric tests; values of p < 0.05 were considered significant. Results. Five animals had early tumor development and five had advanced tumor development. In the GE sequences, early stage metastases showed homogeneous signal reduction attributable to the presence of magnetofluid. Spectrometry found significant differences between the iron concentration in rats with early stage metastases and controls (p=0.002) as well as between rats with early stage metastases and those with late stage metastases (p=0.001). The ratio of exogenous iron in metastases and in liver in early stage rats was 2.6:1. The concentration of exogenous iron in the liver was significantly different from that in tumors only in early stage animals (p=0.043). Conclusions. MRI and spectrometry made it possible to evaluate the vascular distribution of magnetofluid in the liver and revealed the differences in its affinity for metastases in different stages of disease (AU)

[Magnetic resonance imaging and spectrometric study of the distribution of thermotherapeutic magnetofluid after intra-arterial administration in an experimental model of liver metastases]. / Administración intrarterial de un magnetofluido termoterapéutico en un modelo experimental de metástasis hepáticas. Estudio de distribución con resonancia magnética y espectrometría.

OBJECTIVE: To use imaging and laboratory techniques to evaluate the vascular distribution of magnetofluid in a rat model of liver metastases. MATERIAL AND METHODS: The livers of 33 WAG/Rij Crl rats were seeded with CC-531 colorectal cancer cells. After we checked tumor development, 10 rats received hepatic intra-arterial infusions of Lipiodol(®) with nanoparticles of Fe(3)O(4) in suspension, and 5 were reserved as controls. Axial STIR (TR: 3,600 ms/TE: 29 ms/TI: 130 ms) and gradient-echo (GE) (120/4 and 120/14) MRI sequences were acquired on a 1.5 T scanner. After necropsy, rats were classified into one of two stages according to tumor development: early (<10 metastases, each < 3mm) or advanced (>10 metastases, each >3 mm). Samples of liver and of metastases were taken from the 15 animals for quantification of iron concentrations by inductively coupled plasma mass spectrometry (ICP-MS). The data were analyzed using nonparametric tests; values of p < 0.05 were considered significant. RESULTS: Five animals had early tumor development and five had advanced tumor development. In the GE sequences, early stage metastases showed homogeneous signal reduction attributable to the presence of magnetofluid. Spectrometry found significant differences between the iron concentration in rats with early stage metastases and controls (p=0.002) as well as between rats with early stage metastases and those with late stage metastases (p=0.001). The ratio of exogenous iron in metastases and in liver in early stage rats was 2.6:1. The concentration of exogenous iron in the liver was significantly different from that in tumors only in early stage animals (p=0.043). CONCLUSIONS: MRI and spectrometry made it possible to evaluate the vascular distribution of magnetofluid in the liver and revealed the differences in its affinity for metastases in different stages of disease.

Caracterización ecográfica de un modelo experimental de metástasis hepáticas de carcinoma de colon / Ultrasonographic characterization of an experimental model of liver metastases from colon carcinoma in rats

Objetivo: Determinar las características ultrasonográficas de la patología metastásica hepática inducida en un modelo múrido, para evaluar la utilidad de la ecografía en la valoración no invasiva de la infiltración tumoral. Material y métodos: El hígado de 46 ratas WAG/RijCrl fue diseminado con células singénicas de carcinoma colorrectal CC-531 mediante inoculación intraesplénica. En los días 21, 28, 35, 42 y 70 posteriores a la siembra tumoral, se realizaron series de ecografías para valorar inducción tumoral en diferentes grupos de animales; 37 ratas se estudiaron mediante sonda lineal de 10Mhz y 9 con sonda multifrecuencia de 6–18Mhz. Como signos ecográficos de desarrollo tumoral se consideró la detección de nódulos intrahepáticos, festoneado del contorno hepático, megalias de lóbulos y masas extrahepáticas. Los hallazgos ecográficos se verificaron tras necropsia, y en ambas técnicas se determinó el número de implantes, tamaño (<3, entre 3–7 y >7mm) y localización lobular. Resultados: Comparado con los resultados de la necropsia, en ecografía se detectaron lesiones en el 64% de los animales con patología. Todas las masas extrahepáticas fueron correctamente diagnosticadas. Se identificaron metástasis en el 90% de ratas afectadas por lesiones>7mm, en el 75% de animales con implantes de 3–7mm y en el 25% con lesiones<3mm. Con la sonda de 6–18Mhz se detectaron el 50% de lesiones

Objective: To determine the ultrasonographic characteristics of liver metastases induced in a rat model; to evaluate the usefulness of ultrasonography in the noninvasive evaluation of tumor infiltration. Material and methods: We seeded the livers of 46 WAG/RijCrl rats with CC-531 syngeneic colorectal carcinoma cells by intrasplenic inoculation. At 21, 28, 35, 42, 70 days after tumor seeding, we performed a series of ultrasonographic examinations to evaluate tumor induction in different groups of animals: 37 rats were studied with a 10MHz linear probe and 9 were studied with a 6–18MHz multifrequency probe. The following signs were considered indicative of tumor development: intrahepatic nodules, sinuate liver borders, lobe enlargement, and extrahepatic masses. Ultrasonographic findings were verified at autopsy. We determined the number of implants, size (less than 3mm, between 3 and 7mm, or greater than 7mm), and lobe location for each technique. Results: Compared to the autopsy results, ultrasonography detected 64% of the animals with disease. All the extrahepatic masses were correctly diagnosed. Metastases were identified in 90% of the rats with lesions greater than 7mm, in 75% of those with implants between 3 and 7mm, and in 25% of those with lesions less than 3mm. In the group in which we used the 6–18 MHz probe, we detected 50% of the lesions less than 3mm.ConclusionUltrasonography was useful for monitoring the experimental model and enabled the noninvasive oncologic evaluation of the rat liver with reasonable sensitivity (AU)

[Ultrasonographic characterization of an experimental model of liver metastases from colon carcinoma in rats]. / Caracterización ecográfica de un modelo experimental de metástasis hepáticas de carcinoma de colon.

OBJECTIVE: To determine the ultrasonographic characteristics of liver metastases induced in a rat model; to evaluate the usefulness of ultrasonography in the noninvasive evaluation of tumor infiltration. MATERIAL AND METHODS: We seeded the livers of 46 WAG/RijCrl rats with CC-531 syngeneic colorectal carcinoma cells by intrasplenic inoculation. At 21, 28, 35, 42, 70 days after tumor seeding, we performed a series of ultrasonographic examinations to evaluate tumor induction in different groups of animals: 37 rats were studied with a 10 MHz linear probe and 9 were studied with a 6-18 MHz multifrequency probe. The following signs were considered indicative of tumor development: intrahepatic nodules, sinuate liver borders, lobe enlargement, and extrahepatic masses. Ultrasonographic findings were verified at autopsy. We determined the number of implants, size (less than 3mm, between 3 and 7 mm, or greater than 7 mm), and lobe location for each technique. RESULTS: Compared to the autopsy results, ultrasonography detected 64% of the animals with disease. All the extrahepatic masses were correctly diagnosed. Metastases were identified in 90% of the rats with lesions greater than 7 mm, in 75% of those with implants between 3 and 7 mm, and in 25% of those with lesions less than 3mm. In the group in which we used the 6-18 MHz probe, we detected 50% of the lesions less than 3mm. CONCLUSION: Ultrasonography was useful for monitoring the experimental model and enabled the noninvasive oncologic evaluation of the rat liver with reasonable sensitivity.

[Arteriographic correlation in 30 patients with renal vascular disease diagnosed with multislice CT]. / Correlación arteriográfica en 30 pacientes con patología vascular renal diagnosticada mediante TC multicorte.

OBJECTIVE: To determine the usefulness of multislice computed tomography (MSCT) in the evaluation of renal vascular disease against a gold standard of digital subtraction angiography (DSA). MATERIAL AND METHODS: We evaluated 30 patients with arterial hypertension and/or kidney failure that underwent MSCT to rule out a vascular cause and DSA to confirm a vascular cause suspected at MSCT. MSCT examinations were performed on a 10-detector scanner with intravenous administration of 80 ml of iodinated contrast (300 mg iodine/ml) at a flow rate of 5 ml/s. A total of 71 renal arteries, 56 main and 15 accessory, were evaluated. Arterial stenoses were classified as: grade 0 (normal artery), grade I (stenosis < 50%), grade II (> or = 50% and < 70%), grade III (> or = 70%), grade IV (occlusion). Stenosis > or = grade II was considered hemodynamically significant. RESULTS: The findings at MSCT and DSA were identical in 56 (78.8%) renal arteries; MSCT overestimated the degree of stenosis in 13 (18.3%) cases. All grade III stenoses were detected at MSCT. In the diagnosis of hemodynamically significant stenosis, MSCT had a sensitivity of 96.5%, specificity 78.5%, accuracy 85.9%, positive predictive value 75.6%, and negative predictive value 97%. CONCLUSIONS: MSCT is a good noninvasive imaging technique for the evaluation of renal vessels; it is useful for screening patients with kidney disease to rule out potentially treatable vascular causes.

Correlación arteriográfica en 30 pacientes con patología vascular renal diagnosticada mediante TC multicorte / Arteriographic correlation in 30 patients with renal vascular disease diagnosed with multislice CT

Objetivo. Determinar la utilidad de la tomografía computarizada multicorte (TCMC) en la valoración de la patología arterial renal, tomando como patrón oro la angiografía con sustracción digital (ASD). Material y métodos. Se evalúan 30 pacientes con hipertensión arterial o insuficiencia renal, a los que se había realizado una TCMC para descartar etiología vascular de su padecimiento, y en los que ante sospecha de la misma, se practicó una ASD de confirmación diagnóstica. Las TCMC se realizaron en un equipo de 10 detectores, con administración intravenosa de 80 ml de contraste yodado (300 mg de yodo/ml) a flujo de 5 ml/s. Se valoraron 71 arterias renales, 56 principales y 15 accesorias. Las estenosis arteriales se clasificaron para su evaluación en: grado 0 (arteria normal), grado I (estenosis < 50%), grado II (>= 50%, pero < 70%), grado III (>= 70%), grado IV (oclusión). Las estenosis de grado II o superior se consideraron hemodinámicamente significativas. Resultados. En 56 arterias renales (78,8%) se realizó una valoración idéntica en TCMC y ASD. En 13 casos (18,3%) la TCMC sobrevaloró el grado de estenosis. Todas las estenosis de grado III fueron detectadas con TCMC. En el diagnóstico de las estenosis hemodinámicamente significativas la TCMC demostró sensibilidad del 96,5%, especificidad del 78,5%, exactitud del 85,9%, valor predictivo positivo del 75,6% y negativo del 97%. Conclusiones. La TCMC es un buen método de imagen no invasivo en la evaluación de los vasos renales, y resulta útil en el cribado de los pacientes con patología nefrológica en los que se busca descartar una etiología vascular potencialmente tratable (AU)

Objective. To determine the usefulness of multislice computed tomography (MSCT) in the evaluation of renal vascular disease against a gold standard of digital subtraction angio -graphy (DSA). Material and methods. We evaluated 30 patients with arterial hypertension and/or kidney failure that underwent MSCT to rule out a vascular cause and DSA to confirm a vascular cause suspected at MSCT. MSCT examinations were performed on a 10-detector scanner with intravenous administration of 80 ml of iodinated contrast (300 mg iodine/ml) at a flow rate of 5 ml/s. A total of 71 renal arteries, 56 main and 15 accessory, were evaluated. Arterial stenoses were classified as: grade 0 (normal artery), grade I (stenosis < 50%), grade II (>= 50% and < 70%), grade III (>= 70%), grade IV (occlusion). Stenosis >= grade II was considered hemodynamically significant. Results. The findings at MSCT and DSA were identical in 56 (78.8%) renal arteries; MSCT overestimated the degree of stenosis in 13 (18.3%) cases. All grade III stenoses were detected at MSCT. In the diagnosis of hemodynamically significant stenosis, MSCT had a sensitivity of 96.5%, specificity 78.5%, accuracy 85.9%, positive predictive value 75.6%, and negative predictive value 97%. Conclusions. MSCT is a good noninvasive imaging technique for the evaluation of renal vessels; it is useful for screening patients with kidney disease to rule out potentially treatable vascular causes (AU)

[The safety of magnetic resonance imaging: an analysis based on a review of incidents at the Osatek Center]. / Seguridad en resonancia magnética: análisis basado en una revisión de incidentes en Osatek.

OBJECTIVE: To evaluate the dangers to persons in a magnetic resonance imaging (MRI) environment and review Osatek's safety policies. MATERIAL AND METHOD: We review and analyze the incidents occurring throughout our organization from 1994 to 2004 to establish their frequency, causal risk, and effects. Incident registers were implemented in all units in 2001. Data for the initial period prior to 2001 were derived from a survey of Unit Chiefs. We also reviewed other registers (complaints, malpractice suits, Health and Safety Committee). RESULTS: We identified 176 incidentes, 20.4% attributable to specific risks inherent in MRI (missile effect, quench, burns, introduction of patients with contraindications), 69.9% to the injection of contrast agents (adverse reactions and allergies, extravasations), and 9.7% to general risks (medical complications, anxiety, trauma). Among specific risks, the most common was burns, while the incident with greatest potential risk was the missile effect. People were affected in 87% of the incidents; effects on persons were minor in all cases, although one incident occasioned a lawsuit. We consider that 25% of the incidents involving potential or real risks could have been avoided. CONCLUSIONS: Although MRI is a safe technique, it is necessary to establish a safety policy based on preventive measures and staff training to minimize incidents and their effects. The implementation of a quality assurance program provides a starting point that can help to improve the safety of MRI by implementing written registers of incidents.

[Prenatal corticosteroid and early surfactant therapy in infants born at < or = 30 weeks gestation]. / Tratamiento con corticoides prenatales y surfactante precoz en recién nacidos de igual o menos de 30 semanas de gestación.

BACKGROUND: Prenatal corticosteroid (PNC) exposure and postnatal surfactant therapy improve outcome in very low birth weight infants (VLBWI). However, the efficacy of PNC in the prevention of chronic lung disease is debated. OBJECTIVE: To study the effects of PNC exposure on outcome in VLBWI born at < or = 30 weeks' gestation. PATIENTS AND METHODS: We performed a multicenter, longitudinal study. The Spanish Surfactant Group database (n 5 1,275) was searched and 211 VLBWI born at < or = 30 weeks who received early surfactant therapy (< or = 30 min) were identified. Perinatal events, neonatal management and rates of mortality and complications were evaluated. Data on the subgroup of infants who received PNC (157, 74.4 %) were compared with data on 54 infants who did not receive this therapy. RESULTS: Mean (+/- SD) birth weight and gestational age were 944 (226) g and 27 (1.8) weeks. Surfactant was given at 16 +/- 13 min (61 % < or = 15 min). A total of 124 infants (58.8 %) developed respiratory distress syndrome. No differences were found in birth weight, gestational age, or Apgar score at 1 and 5 min. However the age at first surfactant dose was lower in infants exposed to PNC. PNC-exposed infants required fewer doses of surfactant, were extubated earlier (58.9 vs. 161 h) and needed a lower FiO2 at 48 h (0.28 vs. 0.35). Moreover, neonatal mortality (15.9 vs. 27.8 %), the incidence of intraventricular hemorrhage (25.2 vs. 50 %), ductus arteriosus (40.3 vs. 63.5 %) and necrotizing enterocolitis (9 vs. 19.2 %) were lower in infants receiving PNC. However, the incidence of chronic lung disease was similar in both groups. CONCLUSIONS: PNC exposure of VLBWI born at < or = 30 weeks receiving early surfactant therapy reduced mortality and the incidence of certain complications but did not decrease the incidence of chronic lung disease.

[The Europe against immature lung (EURAIL) project. Strategies for the prevention and treatment of lung immaturity in neonates]. / Proyecto EURAIL. Estrategias de prevención y tratamiento contra la inmadurez pulmonar en España.

OBJECTIVE: To determine clinical practice variability in the prevention and postnatal treatment of lung immaturity in Spain. PATIENTS AND METHODS: Cross-sectional study within a larger study in 13 European countries. Data were obtained from the medical records of all very low birth weight (VLBW) infants born in participating centers, without other instrumentation. RESULTS: A questionnaire was sent to 213 centers. Seventy-two (34 %) responded, with 162,157 births (40 % of total births in 1999). Eight percent of infants were of low birth weight, 1.2 % (2,015) of very low birth weight and 0.45 % were of extremely low birth weight. A total of 52.2 % of VLBW infants received at least one dose of prenatal steroids, 28.8 % received a full course and 9.3 % received more than one cycle. All centres used surfactant and 76.8 % had a written protocol. Forty-one percent of VLBW infants were intubated, 47.6 % required mechanical ventilation for more than 6 hours, and 5 % underwent continuous positive airway pressure. A total of 80.4 % used postnatal steroids, half of them for chronic lung disease prevention, and 83.4 % used steroids to treat this disease. Steroids were most frequently indicated at 7-14 days of life for 3-9 days. The most important causes of neonatal morbidity were chronic lung disease in 14 %, ductus arteriosus in 16.7 %, intraventricular hemorrhage in 8.5 %, and necrotizing enterocolitis in 7.3 %. CONCLUSIONS: Prenatal exposure to steroids was low. Repeat cycles and postnatal steroid use to prevent chronic lung disease was high. Recent scientific evidence on the use of pre- and postnatal steroids should be more widely disseminated.

Proyecto EURAIL. Estrategias de prevención y tratamiento contra la inmadurez pulmonar en España / The Europe against immature lung (EURAIL) project. Strategies for the prevention and treatment of lung immaturity in neonates

Objetivo: Conocer la variabilidad de la práctica clínica habitual en la prevención y el tratamiento de la inmadurez pulmonar. Pacientes y métodos Estudio transversal dentro de un estudio en 13 países europeos. De todos los neonatos de muy bajo peso nacidos en los centros colaboradores se recogieron datos de las historias clínicas sin ningún tipo de instrumentación adicional. Resultados La encuesta fue remitida a 213 centros, de los cuales contestaron 72 (34 per cent), con un total de 162.157 nacimientos (40 per cent del total en 1999). El 8 per cent de los recién nacidos eran de bajo peso, el 1,2 per cent de muy bajo peso (2.015) y el 0,45 per cent de extremado bajo peso. El 52,5 per cent de los de muy bajo peso recibieron al menos una dosis de corticoides prenatales, el 28,8 per cent, un ciclo completo, y el 9,3 per cent, más de un ciclo. Todos los centros utilizan algún preparado surfactante, y cuentan con un protocolo escrito el 76,8 per cent. El 41 per cent de los recién nacidos de muy bajo peso fueron intubados al nacer, el 47,6 per cent precisaron ventilación mecánica durante más de 6 h y el 5 per cent presión positiva continua. El 80,4 per cent de centros usaban corticoides posnatales, la mitad para la prevención de enfermedad pulmonar crónica (EPC) y el 83,4 per cent como de terapéutica. La pauta más habitual era indicarlos a los 7-14 días de vida, durante 3-9 días. Entre la morbilidad neonatal destaca la EPC (14 per cent), conducto arterioso sintomático (16,7 per cent), hemorragia intraventricular (8,5 per cent) y enterocolitis necrosante (7,3 per cent). Conclusiones: La tasa de exposición a corticoides prenatales fue baja y la práctica de repetir los ciclos y el empleo de corticoides posnatales para prevenir la EPC elevadas. Sigue siendo preciso difundir la reciente evidencia científica sobre el uso de corticoides prenatales y posnatales (AU)

The cardiovascular effects of partial liquid ventilation in newborn lambs after experimental meconium aspiration.

OBJECTIVE: To study the effects of partial liquid ventilation with perfluorocarbon on cardiovascular function, pulmonary gas exchange, and lung mechanics in term newborn lambs with pulmonary hypertension induced by tracheal instillation of human meconium. DESIGN: Prospective, randomized study. SETTING: Research Unit at a university-affiliated hospital. SUBJECTS: Twelve term newborn lambs (<6 days old). INTERVENTIONS: Lambs were studied in two groups (n = 6): meconium aspiration (3-5 ml/kg 20% meconium solution) managed on pressure-limited conventional mechanical ventilation with or without partial liquid ventilation with perfluorocarbon. MEASUREMENTS AND MAIN RESULTS: Heart rate, systemic and pulmonary arterial pressures, arterial pH and blood gases, cardiac output, and pulmonary mechanics were measured. Partial liquid ventilation in term newborn lambs with experimental meconium aspiration did not alter cardiovascular profile: heart rate, systemic arterial pressure, and cardiac output maintained initial values throughout the experiment. There was a significant improvement in gas exchange (oxygenation increased from values of <100 torr to 338 torr, and ventilation reached normal values in 15 mins). Dynamic compliance increased in 30 mins, reaching basal values (1.1 +/- 0.3 ml/cm H(2)O per kg). Despite the good response (blood gases and cardiovascular profile) to partial liquid ventilation in meconium aspiration syndrome, pulmonary hypertension did not decrease. CONCLUSIONS: Partial liquid ventilation with perfluorocarbon could be a good noninvasive alternative technique that improves gas exchange and pulmonary mechanics in meconium aspiration syndrome without impairing cardiovascular function.

A randomized comparison of surfactant dosing via a dual-lumen endotracheal tube in respiratory distress syndrome. The Spanish Surfactant Collaborative Group.

AIM: To determine if 1-minute instillation of Curosurf via a dual-lumen endotracheal tube without interruption of mechanical ventilation could decrease the incidence of hypoxia (drop in oxygen saturation [SaO2] to <80%, or of transcutaneous partial pressure of oxygen [PtcO2] to <50 mm Hg [6.6 kPa]) and bradycardia (heart rate below 80 beats/minute) at dosing, without affecting the efficacy of the standard bolus delivery. DESIGN: Prospective, multicenter, randomized, nonblinded clinical trial. SETTING: Neonatal intensive care units of the Spanish Surfactant Collaborative Group. PATIENTS AND METHODS: One hundred ninety-eight infants (birth weight 600-2000 g) with respiratory distress syndrome needing mechanical ventilation with a fraction of inspired oxygen [FIO2] 0.40 were randomized before 24 hours to receive 200 mg/kg of Curosurf, either by bolus instillation (n = 99) or by a simplified dosing technique (n = 99), giving the full dose in 1 minute via a dual-lumen endotracheal tube without positioning, interruption of mechanical ventilation, or bagging. Two additional doses (100 mg/kg) were given within 12 and 24 hours of first dose, by the same method, if the infant still needed mechanical ventilation and had a FIO2 0.30. The effects of both procedures on the incidence of acute adverse events at dosing, gas exchange, ventilator requirements, and outcome at 28 days were compared. RESULTS: Fewer episodes of hypoxia (18 vs 40% of doses), and a smaller decrease in heart rate and SaO2 were observed in the dual-lumen group. Efficacy of surfactant, based on improvement of oxygenation, ventilator requirements, and number of doses required, was similar in both groups. Infants in the dual-lumen group had a lower total time exposure to supplemental oxygen (195+/-199 vs 266+/-221 hours). No differences in the incidence of air leaks, intraventricular hemorrhage, patent ductus arteriosus, bronchopulmonary dysplasia, or survival were observed. CONCLUSION: A simplified 1-minute Curosurf dosing procedure via a dual-lumen endotracheal tube without fractional doses, ventilator disconnection, changes in the infant's position, or manual bagging was found to reduce the number of dosing-related adverse transient episodes of hypoxia. Although the simplified method appeared to be as effective as bolus delivery, this should be confirmed in a larger trial.

[Extracorporeal membrane oxygenation (ECMO). I. Is it really needed in Spain?]. / Oxigenación por membrana extracorpórea (ECMO) neonatal. I. Es realmente necesaria en nuestro país?

OBJECTIVE: Extracorporeal membrane oxygenation (ECMO) is a cardiorespiratory support technique used to treat newborns with severe respiratory insufficiency. ECMO has not been used yet in newborns in Spain, with its necessity being question. The aim of this study was to evaluate the need for ECMO for respiratory or cardiac cases in our neonatal population, as well as to study the predictive capacity of several respiratory indices. PATIENTS AND METHODS: A retrospective observational study was carried out. Data from 2,133 newborns admitted during a 48 month period was reviewed. Babies were considered ECMO candidates if they died of respiratory failure or after surgery for a cardiac defect and if they had no ECMO exclusion criteria. The capacity of several respiratory indices to predict mortality was analyzed. RESULTS: We considered 16 babies who died to be ECMO candidates, 6 with respiratory failure (1/3,028 live births) and 10 with cardiac defects 3 of them inborn (1/6,057). The total ECMO need was 1/2019 live births. None of the oxygenation indices studied accurately predicted the 80% mortality rate. CONCLUSIONS: In Spain, it is necessary to start several neonatal ECMO programs since some 200 newborn infants with severe respiratory failure or cardiac defects could benefit from such a program annually.

[Extracorporeal membrane oxygenation (ECMO). II. The development of an experimental model in newborn lambs]. / Oxigenación por membrana extracorpórea (ECMO). II. Desarrollo de un modelo experimental en corderos recién nacidos.

OBJECTIVE: Extracorporeal membrane oxygenation (ECMO) is a technique used for cardiorespiratory support in the treatment of newborns with severe respiratory insufficiency. ECMO has not been used yet in newborns in Spain. The aim of this work was to develop an experimental veno-arterial ECMO model in newborn lambs for training the NICU medical and nursing staff before the clinical application of this technique. MATERIAL AND METHODS: Six newborn lambs were anesthetized, traqueotomized and connected to a neonatal ventilator. The right jugular vein and left carotid artery were cannulated and the catheters were located in the right atrium and aortic arch, respectively. A venous-arterial ECMO was performed during three hours, with an experimental ECMO circuit developed by us. Arterial pH and blood gases, systemic and airway pressures, heart rate, and rectal temperature were monitored. RESULTS: The experimental ECMO circuit developed by use had a very low cost, but was capable of maintaining adequate gas exchange, acid-base balance and a normal rectal temperature. CONCLUSIONS: The development of an experimental ECMO model in newborn lambs may allow the establishment of an initial training program and to maintain the expertise of the NICU staff of a perinatal center planning to start an ECMO program.