If masks don't work why do surgeons wear them? I've received this comment a lot on every single
video I've made about masking. I'm going to tell you the history about why surgeons started wearing
masks, what the research actually tells us about mask wearing in the operating room.
There have been studies done with masked and unmasked operating room staff. Some
of you made interesting comments on my last video about the Cochrane review of 15 masking
studies and I'll answer those questions as well in this video. Now the reasons why surgeons have
historically worn masks have been twofold. Masks have been worn in the operating room
ostensibly to reduce bacteria and saliva from the mouth from contaminating the surgical field
and they possibly would provide some protection to the Physicians and nurses who are wearing them
from inadvertent splashes of bodily fluids. Now bacteria which we all carry in our mouths are
much larger than viruses and are contained in the mask and can be cultured within the mask if
you've been wearing them for a length of time. Surgeons talk during the operations of course
some even sing along to the music that can get played in the OR. We've all had the experience
of someone talking to us and unfortunately receiving some of their saliva on her own face.
This is what masks are designed to prevent. The other reason is that masks would prevent
patient's bodily fluids or blood splashing on the surgeon's face. In many operating rooms all
of the staff in the room have to wear masks. There are obviously different risks between the surgeon
and the surgical assistant who stand beside the patient and others in the room. The surgeon and
surgical assistant are scrubbed in other words they've washed their arms and hands and they
have sterile gowns as well as sterile gloves on. The scrub nurse handing the surgical instruments
is also scrubbed and is also gowned and gloved and stands near the patient. Now the remaining people
in the room are not scrubbed and would include the circulating nurses, the anesthesiologists, porters
who might assist transferring the patient in and out of the room, as well as housekeeping staff.
The question is who in the operating room if any needs to be wearing masks?
Now the interesting thing is that do we truly know that the scrub staff again the surgeon, surgical
assistant, and scrub nurse, need to wear masks like many of my commenters mentioned. The answer
is we just don't know. People assume that they do. You must remember that people make assumptions in
life that just because we do things a certain way means there's definite evidence that that way is
helpful. Sometimes things are done because it's practical or it makes some sense to do it that
way and that's essentially what I'm talking about in this situation but what is the actual evidence?
Well Cochrane actually has published a systematic review of masks in the operating room. For those
that don't know the Cochrane reviews they're considered the gold standard of evidence-based
medicine where they only look at the best studies and review those to formulate the best medical
practices. They're heavily peer reviewed. This is their review and it was published back in 2016.
There have been some newer reviews from other authors including this one in 2021, but there have
not been any good quality randomized trials in the last seven years. Face masks in the operating room
actually date back to 19th century Germany. There have been some observational studies
which have cast doubts on whether face masks are actually needed in the operating room. There was
an observational study back in 1981 in England where no one in the operating room wore masks
for six months. There's a link to the study in the description. Now this was their results and
what they did was they compared the 6 months in the preceding 4 years in a row and you can see
when masks were worn there were about 16 to 19 infections over that time span but during the 6
months of where no masks were worn there were only 8 infections which was a statistically significant
difference. In addition the infections that were cultured during the 6 months with no masks or no
relationship to the bacteria cultured from the surgical staff's nose and throat and while this is
an interesting observational study what we really need is randomized studies where one operating
theater is randomized to mask wearing and to compare it to another operating room theater
where the staff is actually masked. Now there have been three randomized studies that were
reported in the 2016 Cochrane review there were 2,106 participants in the three trials Tunevall
in 1991 reported 13 out of 706 which is 1.8% of post-operative wound infections in the masked
group and 10 out of 723 or 1.4% in the non-masked group and that was not statistically different.
Chamberlain in 1984 had a very small study of only 9 patients in gynecological surgery that reported
no post-op wound infections in the masked group and 3 out of 10 in the non-masked group which had
no statistically significant difference due to a very small sample size. Webster in 2010
randomized the non-scrub staff to masks versus no masking they reported 33 out of 313 patients
or 10.5% in the mass group got infected and 31 out of 340 or 9.1% in the non-masked group. That
was not statistically significant. The Cochrane's conclusion were that from the limited data that
I've just presented it's unclear whether wearing surgical face masks by either surgical team either
increased or reduced the risk of surgical site infection in patients undergoing clean surgery. So
essentially we don't truly know who if any needed to be masked for this surgery in the OR. Better
randomized studies would need to be done and this needs to include a large sample size to detect
clinically important differences in infection rates as well as of course to discriminate between
those who were scrubbed in the room and close to the patient and those who were not scrubbed.
Future research should have clear definitions of the kind of surgery as well as who in the
operating room actually needs face masks. The randomization needs to be done per
operating room list and not per case to avoid contamination of the surgical environment
and guard against bias and follow-up of course needs to extend post-operatively
into the outpatient sphere after the operation to pick up infections that might develop late.
Of course the outcome assessment needs to be blinded to the allocation of masking.
Economic evaluations need to be incorporated. Some hospitals including the world-renowned
Karolinska institute in Sweden have looked at the Cochrane evidence specifically the Webster
study I reported at the end and they've chosen to allow non-scrubbed people such
as anesthesiologists to not wear masks in the operating review given the lack of evidence.
This is approved by their surgeons. It's important to be skeptical of how we all do things in life
whether it's medicine or otherwise ask yourself whether what you're doing is based on evidence
or whether we're simply doing something one way because we've always done it that way.
There's nothing wrong with questioning what we do even things that might intuitively make sense.
Remember that medical reversals happen commonly. It's estimated that about 10 to even 50% of what
we do in medicine will subsequently be reversed. One of my former teachers Dr David Sackett who is
known as one if not the pioneer of evidence-based medicine used to say that 50% of what you learn
in medicine will subsequently found out to be not true but the problem is you don't know which 50%
it is. In the case of masking in the operating room it would be helpful to know whether the
non-scrubbed personnel benefit from masking as well as whether the scrubed personnel need to
be masked. There would be significant costs that could be saved by not masking even time saved from
the staff putting on their masks and tying up their masks. Operating room costs are typically
on the order of ten dollars a minute. Reducing garbage would have significant implications as
well. Next my recent video on the use of masks to prevent Covid generated a lot of comments. As
I mentioned in the video the topic of community masking is extremely polarized with many people
putting forth their opinion on both sides of the spectrum. The key word there is opinion. My video
was based on the Cochrane systematic review of physical interventions to prevent Covid-19. Now
to briefly summarize proper hand washing was found to be helpful in randomized trials as you might
expect but there was low to moderate certainty of evidence that masking was not of any benefit.
Now as expected there was a lot of dissent on the results and the pro masking people made some poor
arguments that it was an example of cherry-picking studies. The systematic reviews by Cochrane are
specifically designed to address the issue of cherry picking. Their process is rigid where every
inclusion exclusion and evaluation is accounted for which is why the actual document is over 300
pages long. Cochrane reviews informed the World Health Organization and government guidelines
because of how thorough their evaluations are. Their system is heavily peer reviewed.
Many of the criticisms of the Cochrane review were that Cochrane did not include poor quality
observational studies showing that masks worked. As I mentioned in my video you can't rely on
heavily confounded observational studies for medical interventions. There were many heavily
confounded observational studies reported in the last three years but unfortunately
the limitations of the studies made the results highly suspect and really completely unhelpful. I
reviewed this study reported by the CDC to show these profound limitations that reported that
even basic cloth masks were very helpful in an observational review but a randomized Bangladesh
study looking at three-Ply cloth masks with a metal nose piece was found to have no benefit.
Now the Cochrane reviewers they only looked at well done randomized studies and that's the
important thing. They concluded as I've mentioned that there was load of moderate confidence in the
results primarily because masting was just not studied in the depth that was clearly needed.
Many governments and organization just assumed that it was going to work even though it's
not been helpful for influenza and we have many randomized studies that look at that.
Despite that mandates were made without hard evidence of benefit.
One of the interesting and frequent comments that I saw was the assumption that the virus
could only be transmitted through the air and that robot or human models using masks was a hundred
percent evidence that masks can be helpful. Now unfortunately respiratory viruses are transmitted
in different ways and we know that. We can find live virus which can subsequently replicate in
humans on surfaces such as people's hands that's why hand washing is helpful the outside of masks
and so on. A lot of the people commented that the reason why masks weren't helpful in studies
is that people weren't using them properly. Although there was teaching in the randomized
studies as to how to wear masks and there's no question that most people don't wear the mask
properly but that's unfortunately real life. Some commenters mentioned that masks would have worked
if people wore them all the time. Now this is obviously impractical and as I mentioned in the
video even health care workers at the hospital take their masks off from time to time and even
in places where there were mandates such as on public transportation masks were allowed to be
removed to eat or drink and this is real life. I hope you found my video today to be informative.
I appreciate you watching until the very end and remember get healthy and stay healthy.