Evaluation of pulse oximetry as a surrogate for PaO2 in awake dogs breathing room air and anesthetized dogs on mechanical ventilation

Kate S. Farrell, Kate Hopper, Laura A. Cagle, Steven E. Epstein

Research output: Contribution to journalArticle

Abstract

Objective: To evaluate the ability of arterial hemoglobin oxygen saturation measurement via pulse oximetry (SpO2) to serve as a surrogate for PaO2 in dogs. Design: Two-part study: prospective observational and retrospective components. Setting: University teaching hospital. Animals: Ninety-two dogs breathing room air prospectively enrolled on a convenience basis. Retrospective evaluation of 1,033 paired SpO2 and PaO2 measurements from 62 dogs on mechanical ventilation. Interventions: Dogs with concurrent SpO2 and PaO2 measured on room air had a data sheet completed with blood gas analysis. SpO2, PaO2, and FiO2 values were collected from medical records of dogs on mechanical ventilation. Measurements and Main Results: Predicted PaO2 was calculated from SpO2 using the dog oxyhemoglobin dissociation curve. The correlation coefficient between measured and predicted PaO2 was 0.49 (P < 0.0001) in room air dogs and 0.74 (P < 0.0001) in ventilated dogs. In room air dogs, Bland–Altman analysis between measured minus predicted PaO2 versus the average showed a mean bias of −6.0 mm Hg (95% limit of agreement, −35 to 23 mm Hg). The correlation coefficient between PaO2/FiO2 and SpO2/FiO2 ratios was 0.76 (P < 0.0001). After combining data sets, receiver operating characteristic curve analysis showed the optimal cutoff value for detecting hypoxemia (PaO2 < 80 mm Hg) was an SpO2 of 95%, with sensitivity and specificity of 77.8% and 89.5%, respectively. Using this cutoff, 6.9% of SpO2 readings failed to detect hypoxemia, whereas 7.2% predicted hypoxemia that was not present. Conclusions: The SpO2 was not clinically suitable as a surrogate for PaO2, though it performed better in mechanically ventilated dogs. As sensitivity for the detection of hypoxemia was poor, pulse oximetry does not appear to be an acceptable screening test. The SpO2/FiO2 ratio may have value for evaluation of anesthetized dogs on supplemental oxygen. Arterial blood gas analysis remains ideal for assessment of oxygenation.

Original languageEnglish (US)
Pages (from-to)622-629
Number of pages8
JournalJournal of Veterinary Emergency and Critical Care
Volume29
Issue number6
DOIs
StatePublished - Nov 1 2019

Fingerprint

Oximetry
Artificial Respiration
breathing
Respiration
Air
Dogs
air
dogs
hypoxia
Blood Gas Analysis
blood gases
Oxygen
oxygen
Oxyhemoglobins
prospective studies
ROC Curve
Teaching Hospitals
Medical Records
Observational Studies
Reading

Keywords

  • blood gas analysis
  • hemoglobin oxygen saturation
  • hypoxemia
  • monitoring

ASJC Scopus subject areas

  • veterinary(all)

Cite this

@article{65a79a01874f47d2ad34922707919eeb,
title = "Evaluation of pulse oximetry as a surrogate for PaO2 in awake dogs breathing room air and anesthetized dogs on mechanical ventilation",
abstract = "Objective: To evaluate the ability of arterial hemoglobin oxygen saturation measurement via pulse oximetry (SpO2) to serve as a surrogate for PaO2 in dogs. Design: Two-part study: prospective observational and retrospective components. Setting: University teaching hospital. Animals: Ninety-two dogs breathing room air prospectively enrolled on a convenience basis. Retrospective evaluation of 1,033 paired SpO2 and PaO2 measurements from 62 dogs on mechanical ventilation. Interventions: Dogs with concurrent SpO2 and PaO2 measured on room air had a data sheet completed with blood gas analysis. SpO2, PaO2, and FiO2 values were collected from medical records of dogs on mechanical ventilation. Measurements and Main Results: Predicted PaO2 was calculated from SpO2 using the dog oxyhemoglobin dissociation curve. The correlation coefficient between measured and predicted PaO2 was 0.49 (P < 0.0001) in room air dogs and 0.74 (P < 0.0001) in ventilated dogs. In room air dogs, Bland–Altman analysis between measured minus predicted PaO2 versus the average showed a mean bias of −6.0 mm Hg (95{\%} limit of agreement, −35 to 23 mm Hg). The correlation coefficient between PaO2/FiO2 and SpO2/FiO2 ratios was 0.76 (P < 0.0001). After combining data sets, receiver operating characteristic curve analysis showed the optimal cutoff value for detecting hypoxemia (PaO2 < 80 mm Hg) was an SpO2 of 95{\%}, with sensitivity and specificity of 77.8{\%} and 89.5{\%}, respectively. Using this cutoff, 6.9{\%} of SpO2 readings failed to detect hypoxemia, whereas 7.2{\%} predicted hypoxemia that was not present. Conclusions: The SpO2 was not clinically suitable as a surrogate for PaO2, though it performed better in mechanically ventilated dogs. As sensitivity for the detection of hypoxemia was poor, pulse oximetry does not appear to be an acceptable screening test. The SpO2/FiO2 ratio may have value for evaluation of anesthetized dogs on supplemental oxygen. Arterial blood gas analysis remains ideal for assessment of oxygenation.",
keywords = "blood gas analysis, hemoglobin oxygen saturation, hypoxemia, monitoring",
author = "Farrell, {Kate S.} and Kate Hopper and Cagle, {Laura A.} and Epstein, {Steven E.}",
year = "2019",
month = "11",
day = "1",
doi = "10.1111/vec.12898",
language = "English (US)",
volume = "29",
pages = "622--629",
journal = "Journal of Veterinary Emergency and Critical Care",
issn = "1479-3261",
publisher = "Wiley-Blackwell",
number = "6",

}

TY - JOUR

T1 - Evaluation of pulse oximetry as a surrogate for PaO2 in awake dogs breathing room air and anesthetized dogs on mechanical ventilation

AU - Farrell, Kate S.

AU - Hopper, Kate

AU - Cagle, Laura A.

AU - Epstein, Steven E.

PY - 2019/11/1

Y1 - 2019/11/1

N2 - Objective: To evaluate the ability of arterial hemoglobin oxygen saturation measurement via pulse oximetry (SpO2) to serve as a surrogate for PaO2 in dogs. Design: Two-part study: prospective observational and retrospective components. Setting: University teaching hospital. Animals: Ninety-two dogs breathing room air prospectively enrolled on a convenience basis. Retrospective evaluation of 1,033 paired SpO2 and PaO2 measurements from 62 dogs on mechanical ventilation. Interventions: Dogs with concurrent SpO2 and PaO2 measured on room air had a data sheet completed with blood gas analysis. SpO2, PaO2, and FiO2 values were collected from medical records of dogs on mechanical ventilation. Measurements and Main Results: Predicted PaO2 was calculated from SpO2 using the dog oxyhemoglobin dissociation curve. The correlation coefficient between measured and predicted PaO2 was 0.49 (P < 0.0001) in room air dogs and 0.74 (P < 0.0001) in ventilated dogs. In room air dogs, Bland–Altman analysis between measured minus predicted PaO2 versus the average showed a mean bias of −6.0 mm Hg (95% limit of agreement, −35 to 23 mm Hg). The correlation coefficient between PaO2/FiO2 and SpO2/FiO2 ratios was 0.76 (P < 0.0001). After combining data sets, receiver operating characteristic curve analysis showed the optimal cutoff value for detecting hypoxemia (PaO2 < 80 mm Hg) was an SpO2 of 95%, with sensitivity and specificity of 77.8% and 89.5%, respectively. Using this cutoff, 6.9% of SpO2 readings failed to detect hypoxemia, whereas 7.2% predicted hypoxemia that was not present. Conclusions: The SpO2 was not clinically suitable as a surrogate for PaO2, though it performed better in mechanically ventilated dogs. As sensitivity for the detection of hypoxemia was poor, pulse oximetry does not appear to be an acceptable screening test. The SpO2/FiO2 ratio may have value for evaluation of anesthetized dogs on supplemental oxygen. Arterial blood gas analysis remains ideal for assessment of oxygenation.

AB - Objective: To evaluate the ability of arterial hemoglobin oxygen saturation measurement via pulse oximetry (SpO2) to serve as a surrogate for PaO2 in dogs. Design: Two-part study: prospective observational and retrospective components. Setting: University teaching hospital. Animals: Ninety-two dogs breathing room air prospectively enrolled on a convenience basis. Retrospective evaluation of 1,033 paired SpO2 and PaO2 measurements from 62 dogs on mechanical ventilation. Interventions: Dogs with concurrent SpO2 and PaO2 measured on room air had a data sheet completed with blood gas analysis. SpO2, PaO2, and FiO2 values were collected from medical records of dogs on mechanical ventilation. Measurements and Main Results: Predicted PaO2 was calculated from SpO2 using the dog oxyhemoglobin dissociation curve. The correlation coefficient between measured and predicted PaO2 was 0.49 (P < 0.0001) in room air dogs and 0.74 (P < 0.0001) in ventilated dogs. In room air dogs, Bland–Altman analysis between measured minus predicted PaO2 versus the average showed a mean bias of −6.0 mm Hg (95% limit of agreement, −35 to 23 mm Hg). The correlation coefficient between PaO2/FiO2 and SpO2/FiO2 ratios was 0.76 (P < 0.0001). After combining data sets, receiver operating characteristic curve analysis showed the optimal cutoff value for detecting hypoxemia (PaO2 < 80 mm Hg) was an SpO2 of 95%, with sensitivity and specificity of 77.8% and 89.5%, respectively. Using this cutoff, 6.9% of SpO2 readings failed to detect hypoxemia, whereas 7.2% predicted hypoxemia that was not present. Conclusions: The SpO2 was not clinically suitable as a surrogate for PaO2, though it performed better in mechanically ventilated dogs. As sensitivity for the detection of hypoxemia was poor, pulse oximetry does not appear to be an acceptable screening test. The SpO2/FiO2 ratio may have value for evaluation of anesthetized dogs on supplemental oxygen. Arterial blood gas analysis remains ideal for assessment of oxygenation.

KW - blood gas analysis

KW - hemoglobin oxygen saturation

KW - hypoxemia

KW - monitoring

UR - http://www.scopus.com/inward/record.url?scp=85074346919&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85074346919&partnerID=8YFLogxK

U2 - 10.1111/vec.12898

DO - 10.1111/vec.12898

M3 - Article

C2 - 31625687

AN - SCOPUS:85074346919

VL - 29

SP - 622

EP - 629

JO - Journal of Veterinary Emergency and Critical Care

JF - Journal of Veterinary Emergency and Critical Care

SN - 1479-3261

IS - 6

ER -