Fresh Gas Flows, Filters, HMEs and Humidification

I recently submitted a “Letter to the Editor” of the BJA in response to the clever study by Zhong and colleagues demonstrating that the use of high fresh gas flows (FGF) during TIVA produces a cost-saving with, importantly, no adverse environmental consequences. My letter was responding to their conclusion regarding the impact of high FGFs on humidification of inhaled gases, and specifically the issue of heat and moisture exchangers (HMEs).

The letter was edited and shortened significantly during the review process, so much so that I felt some important discussion around a commonly misunderstood device was now missing. The published letter is now available here,  but I felt it might be helpful to make the full text of the original letter (with some minor corrections) publicly available, so I have presented it below.

Continue reading “Fresh Gas Flows, Filters, HMEs and Humidification”

Dunny Design

The fact that my emerging interest in Human Factors/Ergonomics and design (see here) coincided to a large degree with me having to spend a lot of time in toilets due to colitis (see here), has meant I’ve developed a, some would say “unhealthy”, obsession fascination interest in the way toilets and bathrooms are designed. It basically means that every time I go into a toilet or a bathroom, I’m paying more attention to what’s around me than I used to. This will include observing things such as taps, sinks, doors, locks, signage, layout (pretty much everything really!), and thinking about the potential impacts, both positive and negative, that these “99% invisible” features have on aspects of life such as personal hygiene, public health, privacy, accessibility, usability, aesthetics and so on.

Continue reading “Dunny Design”

Sibling Rivalry

Image Credit: @KassiIsaac (

I’m sure I’m not the only one, but I’ve often thought of the relationship between my home country, Australia, and that of New Zealand as being much like that of brothers. This brotherhood stretches back more than 100 years before the more well-known voyage of James Cook, to that of Abel Tasman. He sighted Australia on the 24th of November, closely followed by  New Zealand on the 13th of December, in the year 1642. So Australia can claim the title of older brother by a mere 19 days, but we also have landmass and population (excluding sheep) on our side as well. You can also see the family resemblance just by looking at our near-identical national flags.

Continue reading “Sibling Rivalry”