title: Use of end-tidal partial pressure of carbon dioxide to predict arterial partial pressure of carbon dioxide in harp seals during isoflurane-induced anesthesia.
abstract: OBJECTIVE
  To evaluate the relationship between end-tidal partial pressure of CO(2) (ETCO(2)) and PaCO(2) in isoflurane-anesthetized harp seals.
  
  
  METHODS
  Three 5-month-old 25- to 47-kg harp seals (Phoca groenlandica).
  
  
  METHODS
  PaCO(2) was determined in serial arterial samples from isoflurane-anesthetized seals and compared with concomitant ETCO(2) measured with a side-stream microstream capnograph. Twenty-four paired samples were subjected to linear regression analysis and the Bland-Altman method for assessment of clinical suitability of the 2 methods (ie, PaCO(2) and ETCO(2) determinations). The influence of ventilation rate per minute (VR) on the ETCO(2) to PaCO(2) difference (P[ET-a] CO(2)) was examined graphically.
  
  
  RESULTS
  The correlation coefficient between the 2 measurements was 0.94. The level of agreement between ETCO(2) and PaCO(2) varied considerably. Values of ETCO(2) obtained with a VR of < 5 underestimated PaCO(2) to a greater degree (mean bias, -4.01 mm Hg) and had wider limits of agreement of -13.10 to 5.07 mm Hg (-4.01 mm Hg +/- 1.96 SD), compared with a VR of > or = 5 (mean bias, -2.24 mm Hg; limits of agreement, -7.79 to 3.30 mm Hg).
  
  
  CONCLUSIONS
  These results indicate that a microstream sidestream capnograph provides a noninvasive, sufficiently accurate estimation of PaCO(2) with intermittent positive ventilation at a VR > or = 5 in anesthetized harp seals.
authors.affiliation: Département de sciences cliniques, Faculté de médecine vétérinaire, Université de Montréal, St-Hyacinthe, QC, Canada.
authors.forename: Daniel S J
authors.initials: DS
authors.lastname: Pang
authors.forename: Yves
authors.initials: Y
authors.lastname: Rondenay
authors.forename: Eric
authors.initials: E
authors.lastname: Troncy
authors.forename: Lena N
authors.initials: LN
authors.lastname: Measures
authors.forename: Stéphane
authors.initials: S
authors.lastname: Lair
mesh_terms: D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D000818:Animals; D001784:Blood Gas Analysis; D002245:Carbon Dioxide / Q000097:blood*; D007530:Isoflurane / Q000494:pharmacology*; D010313:Partial Pressure; D046049:Phoca / Q000097:blood*; D013990:Tidal Volume / Q000187:drug effects* / Q000502:physiology*
chemical_list: D018685:Anesthetics, Inhalation; D002245:Carbon Dioxide; D007530:Isoflurane