Imputation of Arterial Oxygen Partial Pressures Using Pulse Oximetry

Imputation of Arterial Oxygen Partial Pressures Using Pulse Oximetry in Surgical Patients Under General Anesthesia

The goal of this is prospective cohort study is to to study the relationship between PaO2 and SpO2 in the overall population undergoing general anesthesia in the OT. Secondary aims include studying the relationship between PaO2 and SpO2 in elderly and obese patients undergoing general anesthesia in the OT, validating the derivation of PaO2 from SpO2 using formulas derived by Rice et al. (2009), Pandharipande et al. (2009), and Gadrey et al. (2019) in patients undergoing general anesthesia in the OT, and, if the derivation formulas were not valid, to derive a formula for patients undergoing general anesthesia in the OT.

The included blood samples are arterial blood sample collected for ABGs analysis through either an arterial catheter or an arterial blood puncture in adult patients (Age >18 years) undergoing general anesthesia regardless of the acuity of the surgery (elective, emergency, or lifesaving), the hemodynamic stability of the patient, or the comorbidities. Patients undergoing cardiac or thoracic surgeries will be excluded.

Study Overview

• Status: Not yet recruiting
• Conditions: Anesthesia, General; Respiratory Distress Syndrome; Oxygen Saturation

Detailed Description

The partial pressure of oxygen in the arterial blood (PaO2) / the fraction of inspired oxygen (FiO2) ratio has been commonly used as an indicator of adequate oxygenation and in the diagnosis and severity of acute respiratory distress syndrome (ARDS) which requires arterial blood gas (ABGs) analysis. Another way to measure oxygenation is by using the noninvasive pulse oximetry to measure the oxygen saturation (SpO2). Three formulas have been derived and validated in the intensive care unit (ICU) setting to estimate the PaO2 from the SpO2. However, the relationship of PaO2 and SpO2 and these derivation equations are not validated in the setting of general anesthesia in the operating theatre (OT) in which patients are prone to multiple intraoperative and postoperative pulmonary complications.

The aim is to study the relationship between PaO2 and SpO2 in the overall population undergoing general anesthesia in the OT. Secondary aims include studying the relationship between PaO2 and SpO2 in elderly and obese patients undergoing general anesthesia in the OT, validating the derivation of PaO2 from SpO2 using formulas derived by Rice et al. (2009), Pandharipande et al. (2009), and Gadrey et al. (2019) in patients undergoing general anesthesia in the OT, and, if the derivation formulas were not valid, to derive a formula for patients undergoing general anesthesia in the OT.

This is a prospective cohort study that will be conducted at the American University of Beirut Medical Center (AUBMC) in the OT under the Department of Anesthesiology and Pain Medicine. The data will be collected by the investigators of the study from the patient's chart on EPIC. These include the PaO2 (in mmHg), FiO2, SpO2 (in %), and Mean airway pressure (in cmH2O) at the time of sample collection, in addition to patient characteristics as age, gender, weight, height, BMI, smoking status, surgery type, surgery acuity, and present comorbidities specifically cardiac and respiratory comorbidities.

Validating the use of one of the formulas to derive PaO2 from SpO2 in the OT would help anesthesiologists detect derangements in patients' oxygenation earlier and decrease the need for ABGs analysis and its possible complications.

• Study Type: Observational
• Enrollment (Estimated): 300

Contacts and Locations

• Study Contact: Name: Marwan Rizk, MD; Phone Number: 6380 01350000; Email: mr04@aub.edu.lb
• Study Contact Backup: Name: Thouraya HajAli, MSc; Phone Number: 5738 01350000; Email: th64@aub.edu.lb

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: N/A

• Sampling Method: Non-Probability Sample

Study Population

The included blood samples are arterial blood sample collected for ABGs analysis through either an arterial catheter or an arterial blood puncture in adult patients (Age >18 years) undergoing general anesthesia regardless of the acuity of the surgery (elective, emergency, or lifesaving), the hemodynamic stability of the patient, or the comorbidities. Patients undergoing cardiac or thoracic surgeries will be excluded.

Description

Inclusion Criteria:

• Age >18 years
• Undergoing general anesthesia

Exclusion Criteria:

• Patients undergoing cardiac or thoracic surgeries will be excluded.

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
PaO2	Partial pressure of oxygen in the arterial blood (PaO2)	Before and after intubation

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
SpO2	oxygen saturation (SpO2)	Before and after intubation

Collaborators and Investigators

• Sponsor: American University of Beirut Medical Center
• Investigators: Principal Investigator: Marwan Rizk, MD, American University of Beirut Medical Center

Study record dates

Study Major Dates

• Study Start (Estimated): March 1, 2024
• Primary Completion (Estimated): August 1, 2024
• Study Completion (Estimated): September 1, 2024

Study Registration Dates

• First Submitted: February 22, 2024
• First Submitted That Met QC Criteria: February 22, 2024
• First Posted (Estimated): February 28, 2024

Study Record Updates

• Last Update Posted (Estimated): February 28, 2024
• Last Update Submitted That Met QC Criteria: February 22, 2024
• Last Verified: February 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Respiratory Tract Diseases; Respiration Disorders; Lung Diseases; Infant, Newborn, Diseases; Infant, Premature, Diseases; Respiratory Distress Syndrome; Respiratory Distress Syndrome, Newborn
• Other Study ID Numbers: BIO-2024-0011

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No