Hypoxia
Conditions
Keywords
Cerebral Oximetry, Hypoxia
Brief summary
The purpose of this study is to calibrate and validate a cerebral oximeter product from Cyban Pty. Ltd. The study will involve comparing cerebral oximeter signals against reference arterial and jugular bulb blood gas measures.
Detailed description
The primary objective of the study is to measure the absolute and relative accuracy of the StO2 device by comparing the NIRS-derived brain tissue oxygen saturation with blood-referenced CO-oximeter oxygen saturation values. The CO-oximeter oxygen saturation values from paired arterial and jugular bulb blood samples are combined into a weighted-equation to derive the reference SavO2. Accuracy is reported over a range of oxygen saturations with study subjects exposed to a controlled oxygen desaturation with serial sampling of paired arterial and internal jugular venous blood gas samples.
Interventions
PROCEDUREHypoxia in healthy individuals
The subject will undergo a graduated desaturation procedure. Arterial saturation targets are as follows: 1. 100% 2. 99% 3. 96% 4. 93% 5. 90% 6. 87% 7. 84% 8. 81% 9. 78% 10. 75% 11. 72% 12. 69% 13. 99%
DEVICECerebral Oximetry
Each subject will be continuously monitored with the cerebral oximetry device throughout the desaturation procedure.
DIAGNOSTIC_TESTBlood Gas Sampling
At each arterial saturation plateau venous and arterial blood gas measurements will be taken from the jugular bulb, and the radial artery respectively.
Sponsors
Duke University Hospital, USA
Elliot Teo
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
DIAGNOSTIC
Masking
NONE
Intervention model description
Subject will undergo a graduated desaturation protocol beginning at 100%, then 99%, then descending in 3% increments to a final target of 66%. Arterial and venous jugular bulb co-oximetry measurements will be taken at each saturation plateau yielding a total of 13 paired samples per subject. The weighted average of the SaO2 and the SvO2 will be compared against the Cyban Cerebral Oximeter.
Eligibility
Sex/Gender
ALL
Age
18 Years to 45 Years
Healthy volunteers
Yes
Inclusion criteria
* Healthy, male or female subjects between the ages of 18 to 45 years; * Completion of a health screening for a medical history by a licensed physician, nurse practitioner, or physician assistant; * Minimum weight 40kg; * BMI within range 18.0 - 35.0; * Assigned American Society of Anesthesiologists (ASA) Physical Status 1 by Principal Investigator or delegate
Exclusion criteria
* Prior or known allergies to lidocaine (or similar pharmacologic agents, e.g., Novocain) \[self- reported\]; * Prior known severe allergies to medical grade adhesive/tape (Band-Aid) \[self-reported\]; * Taking any medication other than birth control\[self-reported\]; * Is currently participating in, or has recently participated in (discontinued within 30 days prior to the hypoxia procedure for this study) in an investigational drug, device, or biologic study \[self- reported\]; * Has a negative Allen's Test to confirm non-patency of the collateral artery \[clinical assessment by PI or delegate\]; * Has made a whole blood donation or has had at least 450 ml of blood drawn within 8 weeks prior to the study procedure \[self-reported\]; * Is female with a positive pregnancy test \[serum or urine\], or is female and is unwilling to use effective birth control between the time of screening and study procedure or is breast feeding; * Has anemia \[lab values specific for gender\]; * Has heparin allergy * Has a history of sickle cell trait or thalassemia \[self-reported\]; * Has an abnormal hemoglobin electrophoresis result \[lab measurement\]; * Has a positive urine cotinine test or urine drug screen or oral ethanol test; * Has a room air saturation less than 95% by pulse oximetry \[measurement by PI or delegate\] * Has a clinically significant abnormal EKG \[assessment by PI or delegate\]; * Has a clinically significant abnormal pulmonary function test via spirometry \[assessment by PI or delegate\]; * Has a COHb greater than 3%, or MetHb greater than 2% \[measured by venous blood sample co- oximetry\]. * Students and Employees under the direct supervision of PI or Sub-I.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Bland-Altman Agreement Analysis | 6 months | A Bland-Altman (BA) analysis will be conducted on the difference (D) and mean (A) of StO2, SavO2, where * D = StO2 - SavO2 * A = (StO2 + SavO2) / 2 The following statistics will be presented: * Bias and its 95% confidence interval (CI) * Standard deviation of bias (sum of between and within subject variance components) * Lower and upper 95% limit of agreement (LoA) and their 95% CI |
| Accuracy by Average Root Mean Squared Error | 6 months | The Accuracy by Root Mean Square Difference (ARMS) will be used to evaluate accuracy of the investigational device StO2 compared with the blood-referenced SavO2 |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Passing-Bablok Regression Analysis | 6 months | Passing-Bablok regression is used to compare measurements from different devices, and is a robust nonparametric regression method that does not make assumptions about the distribution of the expected values or the error terms in the model. The 95% CI for the intercept and slope will be estimated from the regression. |
| Subgroup Analysis of Agreement | 6 months | Bland-Altman analyses will be generated for subgroups to assess the two device agreement among different subgroups. A forest plot will used to present the results. The following subgroups will be considered. * Restricted oxygen desaturation range: 50% ≤ reference SavO2 ≤ 75% * Oxygen desaturation steps as measured by SpO2 (13 steps) * Fitzpatrick score group * Sex * Race |
| Linear Mixed Model Regression Analysis | 6 months | A random effects linear mixed model will be used to regress StO2 on SavO2. Subject will be included as a random effect in the model to account for the correlation of repeated measures within the same subject. |
| Concordance Correlation Coefficient | 6 months | The concordance correlation coefficient (CCC) method is used to measure the agreement between of two devices. CCC could have values from -1 to 1, with values near 1 indicating strong concordance between the two devices, values near -1 indicating strong discordance, and values near zero indicating no concordance. |
Other
| Measure | Time frame | Description |
|---|---|---|
| Safety Analyses | 6 months | All safety analyses will be conducted on the Safety Population. No inferential statistical testing will be performed for safety variables. Any reported adverse events, safety observations, and adverse device deficiencies will be listed in a separate by participant data listing. |
Outcome results
None listed