Gas Kinetics and Metabolism in Anesthesia During Non Steady State

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 (Q.T) by vena-caval compression during abdominal surgery, occurrence of CO2 pulmonary embolism during laparoscopy, rising tissue O2 consumption (V.O2) during light anesthesia, and onset of anaerobic metabolism (V.CO2 is disproportionately higher than V.O2).

Conditions

• Anesthetized Healthy Patients (ASA 1 or 2) in the Supine Position, Excluding Head, Neck and Head Surgeries
• Anesthetized Patient With Severe Systemic Disease (ASA 3 or 4)

Interventions

DEVICE

connection of measuring device to anesthesia circuit

same as name

PROCEDURE

drawing of blood sample through an arterial line, placed according to clinical criteria by primary anesthesia team

same

PROCEDURE

changing operating room bed position (head down and up position)

same

PROCEDURE

adding PEEP during anesthesia

same

PROCEDURE

placement of esophageal Doppler for cardiac output measurements

same

DEVICE

Humidity sensor

Small conventional anesthesia T piece including tiny 2 thermometer inside

DEVICE

A mixing chamber (bymixer)

2 mixing chambers (bymixers) composed of 2 arms where one arm serves as a mixing (passive) arm for the measurement of mixed gas fraction. The bymixer is made of conventional anesthesia supplies and does not influence dead space nor circuit resistance.

DEVICE

Pneumotachometer cuvette

The pneumotachometer cuvette is used by many anesthesia monitors to measure gas flow.

DEVICE

Mass spectrometer sampling port

Designed for the anesthesia tubing and connected at the airway opening. it has small volume (3 mL) and do not influence circuit resistance.

Sponsors & Collaborators

• University of California, Irvine

  lead OTHER

Principal Investigators

• Peter H Breen, MD, FRCPC · UCI Medical Center

• Abraham Rosenbaum, MD · UCI Medical Center

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2005-08-31

Primary Completion

2012-01-13

Completion

2012-01-13

Countries

• United States

Study Locations