| Authors | Korman, B. Dash, R.K. Peyton, P.J. |
|---|---|
| Type | Journal Article (Original Research) |
| Journal | Anesthesiology |
| PubMed ID | 29481374 |
| Year of Publication | 2018 |
| URL | https://www.ncbi.nlm.nih.gov/pubmed/29481374 |
| DOI | /10.1097/ALN.0000000000002131 |
| Download |  201806000-00014_.pdf (547.3 KB) |
| Abstract | BACKGROUND: Recent clinical studies suggest that the magnitude of the second gas effect is considerably greater on arterial blood partial pressures of volatile agents than on end-expired partial pressures, and a significant second gas effect on blood partial pressures of oxygen and volatile agents occurs even at relatively low rates of nitrous oxide uptake. We set out to further investigate the mechanism of this phenomenon with the help of mathematical modeling. METHODS: Log-normal distributions of ventilation and blood flow were generated representing the range of ventilation-perfusion scatter seen in patients during general anesthesia. Mixtures of nominal delivered concentrations of volatile agents (desflurane, isoflurane and diethyl ether) with and without 70% nitrous oxide were mathematically modeled using steady state mass-balance principles, and the magnitude of the second gas effect calculated as an augmentation ratio for the volatile agent, defined as the partial pressure in the presence to that in the absence of nitrous oxide. RESULTS: Increasing the degree of mismatch increased the second gas effect in blood. Simultaneously, the second gas effect decreased in the gas phase. The increase in blood was greatest for the least soluble gas, desflurane, and least for the most soluble gas, diethyl ether, while opposite results applied in the gas phase. CONCLUSIONS: Modeling of ventilation-perfusion inhomogeneity confirms that the second gas effect is greater in blood than in expired gas. Gas-based minimum alveolar concentration readings may therefore underestimate the depth of anesthesia during nitrous oxide anesthesia with volatile agents. The effect on minimum alveolar concentration is likely to be most pronounced for the less soluble volatile agents in current use. |
http://www.ibas.org.au/what-we-do/publications/3872945
Motor neurone disease (MND) causes the body's muscles to weaken. Breathing muscle weakness means that most people affected by MND will eventually lose the ability to take a deep breath and cough strongly....
RESPIRATORY BIOMARKERS IN MOTOR NEURONE DISEASE
The inability to breathe is unfortunately the most common cause of death in people living with Motor Neurone Disease (MND). Last year, our clinical research group in Melbourne reported that breathing...
ANZSRS LIFE MEMBERSHIP FOR DANNY BRAZZALE
Danny Brazzale has earned a prestigious ANZSRS Life Membership—held by only 11 people—for his global leadership and dedicated mentorship in respiratory science.
PERTH HIGHLIGHTS: TSANZSRS 2026
A huge congratulations to all our team members who participated in the excellent workshops and meetings at the TSANZSRS Annual Scientific Meeting in Perth in March 2026! Well Done!
BETTER SLEEP, BETTER LIFE TIPS
For World Sleep Day, Dr. Amy Jordan joined the "Get Cereal" panelists Sam and Matilda to share top tips for better sleep, discussing the vital importance of sleep health and hygiene in a podcast interview.
Kudos to Dr. Lauren Booker & Dr. Jen Cori on their JOEM publication examining fatigue detection alarms in rural truck drivers. Their study explores the alarms' effectiveness, accuracy, and habituation, offering key insights into fatigue management.
© 2026 Institute for Breathing and Sleep. All Rights Reserved. ABN 39 093 685 879
Powered by Helmut Design | Manage
