Sonography for determining the optic nerve sheath diameter with increasing intracranial pressure in a porcine model.
J Ultrasound Med
; 30(5): 651-9, 2011 May.
Article
em En
| MEDLINE
| ID: mdl-21527613
ABSTRACT
OBJECTIVES:
This study investigated whether it is feasible to use sonography to monitor changes in the optic nerve sheath diameter in a porcine model.METHODS:
A fiber-optic intracranial pressure transducer was surgically placed through the frontal sinus directly into the brain parenchyma of adult Yorkshire pigs (n = 5). A second bolt was placed on the contralateral side for intraparenchymal fluid infusion. Optic nerve sheath diameter measurements were acquired by each of 2 ultrasound operators around the leading edge of the nerve, 3 to 5 mm distal from the origin of the optic nerve. To induce a change in diameter, intracranial pressure was manipulated by injecting normal saline into the intraparenchymal infusion catheter located in the symmetric contralateral position as the pressure-monitoring probe.RESULTS:
Data from 1 pig were unusable because of a cerebrospinal fluid leak into the sinus and orbital fissure. Saline aliquots of 1 to 10 mL were able to generate intracranial pressures typically starting from 10 to 15 mm Hg and increasing to 75 to 90 mm Hg, which eventually evoked a Cushing response. Fluid injection was controlled to increase pressures by 60 mm Hg over a 15- to 20-minute period. Regression analysis of all animals showed that the optic nerve sheath diameter increased by 0.0034 mm/mm Hg of intracranial pressure; however, this slope ranged from 0.0025 to 0.0046, depending on the animal measured. There was no discernible effect of the ultrasound operator on the slope; however, measurements made by 1 operator were consistently higher than the others by about 8% of the overall diameter range.CONCLUSIONS:
These results suggest that the use of the optic nerve sheath diameter to noninvasively confirm acute changes in intracranial pressure over 1 hour is feasible in a porcine model. We recommend that this method be validated in humans using direct intracranial pressure measurement where possible to confirm it as a screening tool for acute and chronically increased diameters secondary to elevated pressure in clinical settings.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Nervo Óptico
/
Interpretação de Imagem Assistida por Computador
/
Pressão Intracraniana
/
Hipertensão Intracraniana
/
Modelos Animais de Doenças
Tipo de estudo:
Diagnostic_studies
/
Prognostic_studies
Limite:
Animals
/
Female
/
Humans
Idioma:
En
Revista:
J Ultrasound Med
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
Estados Unidos