Pulse oximetry saturation to fraction inspired oxygen ratio as a measure of hypoxia under general anesthesia and the influence of positive end-expiratory pressure

Ravi S Tripathi; James M Blum; Andrew L Rosenberg; Kevin K Tremper

doi:10.1016/j.jcrc.2010.04.009

$Pulse oximetry saturation to fraction inspired oxygen ratio as a measure of hypoxia under general anesthesia and the influence of positive end-expiratory pressure$

Journal article

Peer reviewed

Pulse oximetry saturation to fraction inspired oxygen ratio as a measure of hypoxia under general anesthesia and the influence of positive end-expiratory pressure

Ravi S Tripathi, James M Blum, Andrew L Rosenberg and Kevin K Tremper

Journal of critical care, Vol.25(3), pp.542.e9-542.e13

2010

DOI: 10.1016/j.jcrc.2010.04.009

PMID: 20655696

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Abstract

In ICU patients with acute lung injury, the pulse oximetry saturation (Sp o 2) to fraction of inspired oxygen (F io 2) (S/F) ratio is a reliable surrogate measure for the P/F (Pa o 2/F io 2) ratio. Our goal was to determine the correlation of the S/F to the P/F in a large sample of patients undergoing general anesthesia and the influence of positive end-expiratory pressure (PEEP) on this measure. We studied adult general anesthetics performed with arterial blood gas analysis. Intraoperative data were collected from an anesthesia information system. The S/F ratios corresponding to P/F ratios of 300 were determined. A total of 4439 values were collected. Linear correlation between S/F and P/F was identified ( r = 0.46; P < .01) with a P/F of 300 corresponding to an S/F of 206. The correlation was stronger in patients with 5 to 9 cm PEEP ( r = 0.52; P < .01), more than 9 cm H 2O PEEP ( r = 0.68; P < .01), and a P/F ratio of 300 or less ( r = 0.61; P < .01). The S/F correlates with the P/F in our cohort of patients undergoing general anesthesia, especially those ventilated with PEEP more than 9 cm H 2O and/or with P/F less than 300. It has use as a noninvasive measure to screen for increased pulmonary dysfunction and to trend oxygenation during a general anesthetic.

ARDS

ALI

P-to-F ratio

S-to-F ratio

Details

Title: Subtitle: Pulse oximetry saturation to fraction inspired oxygen ratio as a measure of hypoxia under general anesthesia and the influence of positive end-expiratory pressure
Creators: Ravi S Tripathi
James M Blum
Andrew L Rosenberg
Kevin K Tremper
Resource Type: Journal article
Publication Details: Journal of critical care, Vol.25(3), pp.542.e9-542.e13
Publisher: Elsevier Inc
DOI: 10.1016/j.jcrc.2010.04.009
PMID: 20655696
ISSN: 0883-9441
eISSN: 1557-8615
Language: English
Date published: 2010
Academic Unit: Anesthesia
Record Identifier: 9984013274802771

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