Ignite Creation Date:
2024-05-05 @ 12:03 PM
Last Modification Date:
2024-10-26 @ 9:19 AM
Study NCT ID:
NCT00225381
Status:
WITHDRAWN
Last Update Posted:
2021-03-23
First Post:
2005-09-21
Brief Title:
Gas Kinetics and Metabolism in Anesthesia During Non Steady State
Sponsor:
University of California Irvine
Organization:
University of California Irvine
Study Overview
Official Title:
Gas Kinetics and Metabolism in Anesthesia During Non Steady State
Status:
WITHDRAWN
Status Verified Date:
2021-03
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Non Applicable clinical trial
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
During clinical anesthesia it is astonishing that CO2 monitoring consists mainly of end-tidal PCO2 to confirm endotracheal intubation and to estimate ventilation and O2 monitoring consists of a single PO2 measurement to detect a hypoxic gas mixture Better understanding of how O2 and CO2 kinetics monitoring can define systems pathophysiology will greatly enhance safety in anesthesia by detecting critical events such as abrupt decrease in cardiac output QT by vena-caval compression during abdominal surgery occurrence of CO2 pulmonary embolism during laparoscopy rising tissue O2 consumption VO2 during light anesthesia and onset of anaerobic metabolism VCO2 is disproportionately higher than VO2
Detailed Description:
During clinical anesthesia it is astonishing that CO2 monitoring consists mainly of end-tidal PCO2 to confirm endotracheal intubation and to estimate ventilation and O2 monitoring consists of a single PO2 measurement to detect a hypoxic gas mixture Better understanding of how O2 and CO2 kinetics monitoring can define systems pathophysiology will greatly enhance safety in anesthesia by detecting critical events such as abrupt decrease in cardiac output QT by vena-caval compression during abdominal surgery occurrence of CO2 pulmonary embolism during laparoscopy rising tissue O2 consumption VO2 during light anesthesia and onset of anaerobic metabolism VCO2 is disproportionately higher than VO2
In the previous grant period discoveries of CO2 kinetics during non-steady state revealed significant gaps in understanding of O2 kinetics To this end a 5-compartment lung model of gas kinetics in the body during non-steady state has been developed that incorporates complex interactions between O2 and CO2 in the lung blood and tissues This computer model was used to formulate the following hypotheses and will elucidate mechanisms underlying the subsequent measured data in anesthetized patients
The investigators have already developed two innovative devices that are essential for the VO2 measurement A fast response temperature and humidity sensor and a mixing device a bymixer for the measurement of mixed gas fraction especially designed for anesthesia systems The investigators have also designed a sophisticated bench system for the validation of both devices which showed the high accuracy and performance of our measurements
Hypotheses that will be tested in our overall research theme include
That pulmonary O2 uptake VO2 in anesthetized patients is much lower than the value quoted in the literature
That inhalation anesthesia influences VO2 differently than total intravenous anesthesia TIVA
That an acute decrease in cardiac output QT by patient position change will transiently decrease VO2 but the decrease in CO2 elimination VCO2 is sustained because tissue CO2 stores are a hundred fold greater than O2 please see previously approved IRB protocol HS 2000-1325
That positive end-expiratory pressure PEEP decreases VO2 and VCO2 due to decreases in QT and alveolar ventilation VA and appearance of high ventilation-to-perfusion VAQ units please see previously approved IRB protocol HS 2000-1325
That Trendelenburg head down position increases VO2 and VCO2 due to increase in QT
That VO2 can help to determine the necessity of blood transfusion
That the continuous measurement of the respiratory quotient RQVCO2VO2 can detect transition to anaerobic metabolism
That the continuous measurement of the respiratory RQ can be a good alternative to arterial blood gas sampling
That the continuous measurement of the respiratory RQ can determine the necessity of nutritional support during long operations
In this protocol the investigators will study the clinical implications of these measurements believing that they are the missing links in anesthesia monitoring Elucidating the mechanisms underlying this acute pathophysiology will advance the understanding of O2 and CO2 kinetics during non-steady state and allow the non-invasive diagnosis of critical events during clinical anesthesia conferring increased safety especially for the majority of healthy patients who receive only non-invasive monitoring
A separate section of the study which compliments the metabolic gas exchange study with the bymixer flow system is the examination of respiratory gas with a portable mass-spectrometer to detect volatile organic compounds during anaerobic metabolism The experimental anaerobic model is adult patients undergoing a surgery that requires tourniquet Anaerobic metabolism will be detected by acid base balance blood test the bymixer flow measurement and the mass spectrometer Anesthesia will be maintained by total intravenous anesthesia TIVA and each patient will have an arterial line No other intervention would be taken It is an observational type study
In the previous grant period discoveries of CO2 kinetics during non-steady state revealed significant gaps in understanding of O2 kinetics To this end a 5-compartment lung model of gas kinetics in the body during non-steady state has been developed that incorporates complex interactions between O2 and CO2 in the lung blood and tissues This computer model was used to formulate the following hypotheses and will elucidate mechanisms underlying the subsequent measured data in anesthetized patients
The investigators have already developed two innovative devices that are essential for the VO2 measurement A fast response temperature and humidity sensor and a mixing device a bymixer for the measurement of mixed gas fraction especially designed for anesthesia systems The investigators have also designed a sophisticated bench system for the validation of both devices which showed the high accuracy and performance of our measurements
Hypotheses that will be tested in our overall research theme include
That pulmonary O2 uptake VO2 in anesthetized patients is much lower than the value quoted in the literature
That inhalation anesthesia influences VO2 differently than total intravenous anesthesia TIVA
That an acute decrease in cardiac output QT by patient position change will transiently decrease VO2 but the decrease in CO2 elimination VCO2 is sustained because tissue CO2 stores are a hundred fold greater than O2 please see previously approved IRB protocol HS 2000-1325
That positive end-expiratory pressure PEEP decreases VO2 and VCO2 due to decreases in QT and alveolar ventilation VA and appearance of high ventilation-to-perfusion VAQ units please see previously approved IRB protocol HS 2000-1325
That Trendelenburg head down position increases VO2 and VCO2 due to increase in QT
That VO2 can help to determine the necessity of blood transfusion
That the continuous measurement of the respiratory quotient RQVCO2VO2 can detect transition to anaerobic metabolism
That the continuous measurement of the respiratory RQ can be a good alternative to arterial blood gas sampling
That the continuous measurement of the respiratory RQ can determine the necessity of nutritional support during long operations
In this protocol the investigators will study the clinical implications of these measurements believing that they are the missing links in anesthesia monitoring Elucidating the mechanisms underlying this acute pathophysiology will advance the understanding of O2 and CO2 kinetics during non-steady state and allow the non-invasive diagnosis of critical events during clinical anesthesia conferring increased safety especially for the majority of healthy patients who receive only non-invasive monitoring
A separate section of the study which compliments the metabolic gas exchange study with the bymixer flow system is the examination of respiratory gas with a portable mass-spectrometer to detect volatile organic compounds during anaerobic metabolism The experimental anaerobic model is adult patients undergoing a surgery that requires tourniquet Anaerobic metabolism will be detected by acid base balance blood test the bymixer flow measurement and the mass spectrometer Anesthesia will be maintained by total intravenous anesthesia TIVA and each patient will have an arterial line No other intervention would be taken It is an observational type study
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
None
Is a FDA Regulated Device?:
None
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None
Secondary IDs
| Secondary ID | Type | Domain | Link |
|---|---|---|---|
| UCI IRB ID2005-4256 | OTHER | UC Irvine Institutional Review Board | None |