Effects of instrumental dead space reduction during weaning from synchronized ventilation in preterm infants.

OBJECTIVE: A majority of the modalities of synchronized ventilation in preterm infants require the use of flow sensors that can increase dead space and may adversely affect ventilator weaning. The objective of this study was to assess the effects of flow sensor dead space during synchronized intermittent mandatory ventilation (SIMV) weaning in preterm infants. STUDY DESIGN: Twelve preterm infants (gestational age 25+/-2 weeks, birth weight 705+/-158 g, age: 31+/-186 days, SIMV rate: 25+/-8 breaths min(-1), peak inspiratory pressure 18+/-2 cm H(2)O, positive end-expiratory pressure: 5+/-0.5 cm H(2)O, pressure support: 9+/-3 cm H(2)O, fraction of inspired oxygen: 34+/-6%) underwent two 2.5-h weaning periods during which SIMV rate was reduced twice by 5 breaths min(-1) at 30-min intervals as tolerated, with and without reduction of flow sensor dead space, in random sequence. A 30-min baseline was obtained before each weaning period. Dead space was reduced by flushing the flow sensor with a continuous gas leak flow in the endotracheal tube connector. RESULT: Transcutaneous CO(2) tension during SIMV weaning periods without and with reduced dead space did not differ from baseline, whereas total minute ventilation and tidal volume were lower during the SIMV weaning period with reduced dead space. Three infants did not tolerate SIMV weaning without while one infant did not tolerate weaning with reduced dead space. CONCLUSION: SIMV weaning elicited a compensatory rise in spontaneous ventilation. When flow sensor dead space was reduced during SIMV weaning, gas exchange was maintained with lower minute ventilation. Instrumental dead space imposes a ventilatory burden during SIMV weaning in small preterm infants.

Further analysis on the structural proteins of infectious pancreatic necrosis virus.

The structural proteins of infectious pancreatic necrosis virus (IPNV) have been analyzed. Two-dimensional gel electrophoresis showed that IPNV proteins are slightly acidic with apparent pIs ranging from 5.8 to 6.6. To identify the IPNV surface-located proteins, purified virus was labelled either with fluorescein isothiocyanate (FITC) or with Na 125I. After analysis by SDS-PAGE, only the major viral protein, VP2, was labelled by either procedure. The accessibility of VP2 to these reagents suggests that this protein is externally located. In addition, using Concanavalin A conjugated with FITC and IPNV labelling with 3H-mannose, evidence is present that VP2 contains carbohydrate residues.

Lesiones quísticas de la órbita / Cystic orbital injuries

En 40 pacientes portadores de lesiones quísticas, es decir, de ubicación retroseptal, analizamos su comportamiento clínico, incidencia patológica y manejo terapéutico. Incluimos a niños y adultos, cuyas edades fluctuaron entre pocos días y 77 años, siendo 22 mujeres y 18 hombres. Las lesiones encontradas correspondieron a primarias, preferentemente en niños y, secundarias, principalmente en adultos. Los quistes primarios encontrados en 31 pacientes (77,5%) fueron los siguientes: dermoides, 14 (35%); quistes epiteliales simples, en 5 (12,5%); microftalmo con quiste o quistes colobomatosos, en 3 (7,5%); quistes hemáticos, en 3 (7,5%); ojo quístico congénito o criptoftalmo, en 2 (5%); 1 teratoma y 1 quiste hidatídico con 2,5% cada uno. Como lesiones secundarias encontramos al mucocele, de origen frontal especialmente, en 9 casos (22,5%) y 2 (5%) meningoceles. Clínicamente se mostraron por proptosis y desplazamiento ocular progresivo, con o sin compromiso periorbitario dependiendo del tamaño e inflamación de la lesión, muchos de los cuales lo hacían en forma paulatina. El aspecto evolutivo obligó a plantear un tratamiento quirúrgico en la mayoría de éstos, en tanto que en unos pocos solamente los observamos

Codificación, casuística e incidencia de la patología orbitaria / Codification, cases and incidence of orbitary pathology

Mediante una clasificación codificada de las enfermedades de la órbita, hemos analizado la frecuencia de dichas afecciones en 216 casos, encontrando que la orbitopatía endocrina y las lesiones neoplásicas ocupan los primeros lugares. Se presentan tres casos clínicos; uno, inflamatorio originado en paciente con lupus sistémico; otro tumoral, en mujer portadora de Nevus de Ota con melanoma maligno orbitario y finalmente, una fístula carótido-cavernosa, tratada con balonización exitosamente