In vitro validation of a Pitot-based flow meter for the measurement of respiratory volume and flow in large animal anaesthesia.
Vet Anaesth Analg
; 36(3): 209-19, 2009 May.
Article
en En
| MEDLINE
| ID: mdl-19397772
ABSTRACT
OBJECTIVE:
To remodel and validate commercially available monitors and their Pitot tube-based flow sensors for use in large animals, using in vitro techniques. STUDYDESIGN:
Prospective, in vitro experiment.METHODS:
Both the original and the remodelled sensor were studied with a reference flow generator. Measurements were taken of the static flow-pressure relationship and linearity of the flow signal. Sensor airway resistance was calculated. Following recalibration of the host monitor, volumes ranging from 1 to 7 L were generated by a calibration syringe, and bias and precision of spirometric volume was determined. Where manual recalibration was not available, a conversion factor for volume measurement was determined. The influence of gas composition mixture and peak flow on the conversion factor was studied.RESULTS:
Both the original and the remodelled sensor showed similar static flow-pressure relationships and linearity of the flow signal. Mean bias (%) of displayed values compared with the reference volume of 3, 5 and 7 L varied between -0.4% and +2.4%, and this was significantly smaller than that for 1 L (4.8% to +5.0%). Conversion factors for 3, 5 and 7 L were very similar (mean 6.00 +/- 0.2, range 5.91-6.06) and were not significantly influenced by the gas mixture used. Increasing peak flow caused a small decrease in the conversion factor. Volume measurement error and conversion factors for inspiration and expiration were close to identity.CONCLUSION:
The combination of the host monitor with the remodelled flow sensor allowed accurate in vitro measurement of flows and volumes in a range expected during large animal anaesthesia. CLINICAL RELEVANCE This combination has potential as a reliable spirometric monitor for use during large animal anaesthesia.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Respiración Artificial
/
Anestesia por Inhalación
/
Mediciones del Volumen Pulmonar
/
Monitoreo Fisiológico
Tipo de estudio:
Guideline
Límite:
Animals
Idioma:
En
Revista:
Vet Anaesth Analg
Asunto de la revista:
ANESTESIOLOGIA
/
MEDICINA VETERINARIA
Año:
2009
Tipo del documento:
Article
País de afiliación:
Austria