title: Respiratory mechanics in sedated and nonsedated adult llamas.
abstract: OBJECTIVE
  To validate the use of noninvasive pulmonary function testing in sedated and nonsedated llamas and establish reference range parameters of respiratory mechanical function.
  
  
  METHODS
  10 healthy adult llamas.
  
  
  METHODS
  Pulmonary function testing in llamas included the following: measurement of functional residual capacity (FRC) via helium dilution, respiratory inductance plethysmography (RIP) to assess breathing pattern and flow limitations, esophageal-balloon pneumotachography, and a monofrequency forced oscillatory technique (FOT; 1 to 7 Hz) before and after IM administration of xylazine (0.2 mg/kg).
  
  
  RESULTS
  The following mean +/- SD measurements of respiratory function were obtained in nonsedated llamas: FRC (5.60 +/- 1.24 L), tidal volume (1.03 +/- 0.3 L), dynamic compliance (0.83 +/- 0.4 L/cm H(2)O), pulmonary resistance (R(L); 1.42 +/- 0.54 cm H(2)O/L/s), and respiratory system resistance (2.4 +/- 0.9, 2.3 +/- 0.7, 2.2 +/- 0.6, 2.7 +/- 0.7, and 2.5 +/- 0.5 cm H(2)O/L/s at 1, 2, 3, 5, and 7 Hz, respectively) by use of FOT. Measurements of flow limitations via RIP were comparable to other species. Sedation with xylazine induced significant increases in R(L) and maximum change in transpulmonary pressure. Following sedation, a mean 127% increase in R(L) and mean 116% increase in respiratory system resistance were observed across 1 to 7 Hz. The magnitude of change in respiratory system resistance increased with decreasing impulse frequency, suggesting bronchoconstriction.
  
  
  CONCLUSIONS
  Noninvasive pulmonary function testing is well tolerated in untrained unsedated llamas. These techniques have clinical applications in the diagnosis and treatment of respiratory tract disease, although testing should not be performed after sedation with xylazine.
authors.affiliation: Department of Clinical Sciences, Cummings School of Veterinary Medicine at Tufts University, North Grafton, MA 01536, USA.
authors.forename: Kara M
authors.initials: KM
authors.lastname: Lascola
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Hoffman
authors.forename: Melissa R
authors.initials: MR
authors.lastname: Mazan
authors.forename: Daniela
authors.initials: D
authors.lastname: Bedenice
mesh_terms: D000375:Aging; D000818:Animals; D002161:Camelids, New World / Q000502:physiology*; D005260:Female; D006993:Hypnotics and Sedatives / Q000494:pharmacology*; D008297:Male; D012016:Reference Values; D012143:Respiratory Physiological Phenomena
chemical_list: D006993:Hypnotics and Sedatives