Dive Pacific 175 Dec2020 Jan 2021
Dive Pacific, New Zealand's Dive Magazine , captures the best of diving in New Zealand and the Pacific. with adventures, top photos and expert technical advice
Dive Pacific, New Zealand's Dive Magazine , captures the best of diving in New Zealand and the Pacific. with adventures, top photos and expert technical advice
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DIVEMEDICINE<br />
Why a diver should avoid Covid-19 and<br />
what happens if they don’t<br />
By Professor Simon Mitchell, University of Auckland<br />
It is easy to run out of adjectives in describing this very strange year. “Unprecedented” is one you<br />
hear quite a lot. The truth is most of the hyperbole is pretty well justified. The world has been<br />
thrown into economic and social turmoil by the pandemic caused by SARS-CoV-2, and tragically,<br />
a lot of people have lost their lives or livelihoods.<br />
We in New Zealand have been<br />
relatively lucky, though<br />
to a large extent we made our<br />
own luck. The early successful<br />
lockdown was a testament to<br />
both good leadership and highly<br />
commendable buy-in by the kiwi<br />
public at large.<br />
As a sharp end medical practitioner<br />
(an anaesthetist) I for one<br />
am deeply grateful. I was on the<br />
intubation team tasked with<br />
putting very sick covid patients on<br />
ventilators at Auckland Hospital.<br />
We were envisaging Italy or<br />
the USA or the UK here, and it<br />
simply never happened. Indeed,<br />
although we intubated a number<br />
of suspected cases, not a single<br />
one actually turned out to have<br />
the virus.<br />
The fact that we eliminated that<br />
outbreak and several subsequent<br />
ones from the community should<br />
be a source of great pride. It may<br />
not last, but let’s hope it does.<br />
I say let’s hope it does because<br />
contrary to early opinions, this<br />
disease is not as forgiving as<br />
many had assumed it to be.<br />
Unforgiving<br />
Early in the pandemic, outcomes<br />
following covid-19 infection were<br />
often portrayed as binary: you<br />
either died, and that was rare,<br />
or you lived, by far the most<br />
common outcome, allegedly<br />
without any problems. “In most<br />
people its just like a common<br />
cold” was an opinion often<br />
expressed.<br />
No. Its. Not.<br />
This is a far more serious disease<br />
…Sicker patients can also develop other strange manifestations,<br />
like a tendency for blood to clot more easily. This has led to<br />
events like strokes, sometimes in young patients. Some patients<br />
also seem to develop a virally induced weakening of their heart<br />
that leaves them with markedly reduced exercise capacity…<br />
than the common cold, or influenza.<br />
Yes, it remains true the<br />
vast majority of people survive<br />
Covid-19, but depending on how<br />
complications are defined, a large<br />
proportion of survivors suffer<br />
them, and if you are a diver some<br />
of those complications could be of<br />
substantial significance.<br />
Massive inflammatory/immune<br />
response<br />
In some respects, Covid-19 is a<br />
typical respiratory virus. Early in<br />
an infection it produces cold-like<br />
upper respiratory tract symptoms,<br />
albeit with some unusual variations<br />
like loss of taste or smell.<br />
Later, it can spread to the lower<br />
respiratory tract producing a<br />
pneumonia-like disease typically<br />
involving both lungs. Nothing<br />
particularly unusual there, but<br />
this is where things can begin to<br />
go off the rails.<br />
In some patients, but not others,<br />
spread to the lungs appears to<br />
elicit a massive inflammatory/<br />
immune response that, simply<br />
put, does more harm than good.<br />
The lungs can become extremely<br />
congested with inflammatory<br />
material making breathing difficult<br />
and oxygenation increasingly<br />
inefficient. This is when patients<br />
sometimes require intubation<br />
and ventilation, though the<br />
more recent trend is to have a<br />
higher threshold for doing that.<br />
Experience has shown us that<br />
patients can do better if we can<br />
avoid mechanical ventilation.<br />
Clinicians are getting more accustomed<br />
to tolerating moderate<br />
degrees of hypoxia and trying to<br />
nurse patients through without<br />
intubating them.<br />
The sicker patients can also<br />
develop other strange manifestations,<br />
like a tendency for blood<br />
to clot more easily. This has led<br />
to events like strokes, sometimes<br />
in young patients. Some patients<br />
also seem to develop a virally<br />
induced weakening of their heart<br />
that leaves them with markedly<br />
reduced exercise capacity.<br />
Given that we have only been<br />
dealing with this disease for a<br />
short time, we don’t understand<br />
the natural history of this complication.<br />
Patients may recover, but<br />
may not; only time will tell.<br />
Change in the lungs<br />
From a diver’s point of view the<br />
most concerning complication<br />
is medium to long-term change<br />
in the lungs. Covid-19 appears<br />
capable of producing sustained<br />
changes in the lungs, call it<br />
‘scarring,’ for want of a simpler<br />
description, that the patient may<br />
never recover from.<br />
Again, the natural history of<br />
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