AUTHOR=Ramponi Giacomo , Gianni Francesca , Karlafti Eleni , Piazza Isabelle , Albertoni Francesco , Colombo Giorgio , Casazza Giovanni , Garegnani Anna , Casella Rosa , Costantino Giorgio 

TITLE=The diagnostic accuracy of carbon monoxide pulse oximetry in adults with suspected acute carbon monoxide poisoning: a systematic review and meta-analysis

JOURNAL=Frontiers in Medicine

VOLUME=Volume 10 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2023.1250845

DOI=10.3389/fmed.2023.1250845

ISSN=2296-858X

ABSTRACT=INTRODUCTION: Acute carbon monoxide poisoning (COP) is one of the leading causes of intoxication among patients presenting to the emergency department (ED). COP symptoms are not always specific and may vary from mild to critical illness. In the last few years, COHb pulse oximeters have been developed and applied to the setting of suspected COP. The aim of this systematic review is to assess the diagnostic accuracy of CO pulse oximetry (SpCO) with carboxyhemoglobin (COHb) levels measured by blood gas analysis, used as reference standard, in patients with suspected COP.
METHODS: We developed our search strategy according to the PICOS framework: Population, Index/Intervention, Comparison, Outcome, Study, considering the diagnostic accuracy of SpCO compared to COHb levels measured by blood gas analysis, used as reference standard, in patients with suspected COP, enrolled in cross-sectional studies in English language. The search was performed on MEDLINE/PubMed and EMBASE in February 2022. Quality assessment was performed with the QUADAS-2 methodology. A COHb cut-off of 10% was chosen to test the sensitivity and specificity of the index test. The bivariate model was used to perform the meta-analysis. The protocol was registered on PROSPERO (CRD42022359144). 
RESULTS: A total of 6 studies (1734 patients) were included. The pooled sensitivity of the test was 0.65 (95% CI 0.44-0.81) and the pooled specificity was 0.93 (95% CI 0.83-0.98). The pooled LR+ was 9.4 (95% CI 4.4 to 20.1) and the pooled LR- was 0.38 (95% CI 0.24 to 0.62).
CONCLUSIONS: 
Our results show that SpCO cannot be used as a screening tool in COP in the ED due to its low sensitivity. Thanks to its high LR+, it would be interesting to evaluate on larger samples, with a prospective design, if SpCO could have a role in the prehospital setting as a tool to quickly identify COP patients and prioritize their transport to specialized hospitals.