Evaluation of head-out constant volume body plethysmography for measurement of specific airway resistance in conscious, sedated sheep.
OBJECTIVE
To evaluate the use of a modified whole body plethysmograph in awake sheep.


METHODS
10 healthy adult sheep.


METHODS
Concurrent measurements of specific airway resistance (sR(aw)) and pulmonary resistance (R(L)) were obtained using a novel noninvasive head-out constant-volume plethysmograph and esophageal balloon-pneumotachography, respectively. All data were collected before and after external resistive loading with 1 and 5.6 cm H2O/L/s. Functional residual capacity (FRC) was measured by helium dilution for computation of airway resistance (R(aw)) preloading (R(aw) = sR(aw)/FRC).


RESULTS
The sR(aw) and R(L) were closely correlated in 10 adult sheep. Additionally, sR(aw), and R(L) accurately reflected the magnitude of added resistance. The mean FRC was 52 mL/kg and used to calculate R(aw). At baseline, the values for R(aw) were significantly correlated with sR(aw) and R(L).


CONCLUSIONS
Precise measurements of sR(aw) and R(aw) at baseline and sR(aw) after external resistive loading were obtained by use of this novel noninvasive plethysmographic technology. This method should have application to veterinary patients or animals used in research in which noninvasive rapid or serial measurements of sR(aw) in the conscious state are required.
Department of Clinical Sciences, School of Veterinary Medicine, Tufts University, North Grafton, MA 01536, USA.
Daniela
D
Bedenice
Ephraim
E
Bar-Yishay
Edward P
EP
Ingenito
Larry
L
Tsai
Melissa R
MR
Mazan
Andrew M
AM
Hoffman
D000403:Airway Resistance / Q000502:physiology*; D000704:Analysis of Variance; D000818:Animals; D005069:Evaluation Studies as Topic; D005652:Functional Residual Capacity; D006371:Helium; D010993:Plethysmography, Whole Body / Q000379:methods*; D015656:Respiratory Mechanics / Q000502:physiology*; D012756:Sheep / Q000502:physiology*
D006371:Helium