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Is the new professionalism and ACP's new ethics really just about following guidelines?

The Charter ( Medical Professionalism in the New Millennium.A Physician's Charter) did not deal with just the important relationship of ...

Sunday, March 29, 2020

Role of masks for COVID prevention outside of hosptial use

The following is my opnion and not a medical recommendation.

 Public face mask use appears to be common in Asian countries and also is now required in 
the Czeck Republic where people wear masks as a civil duty with the realization that "I protect you by wearing a mask and you protect me by wearing a mask."

Corona virus is spread by droplets by infected person even if they are asymtomatic and both simple surgical type face masks and the more expensive and protective N 95 masks can significantly reduce spread of coronavirus.

Both type of masks have been scarce in the US as Covid 19 cases exploded. Expectations and then realization of actual mask shortages in medical care facilities lead public health officials to discourage the public from using masks in the hope that more would be available for health care workers

Sometimes it has been argued that the masks were not effective when used by the public while at the same time saying that the masks should be reserved for medical personnel use in whose hands they would somehow offer important protection to them. Of course, protection is not a function of one's profession.

It is likely that it was believed that  officially recommending masks would lead to a large public demand  , making it even more difficult for health facilities to obtain masks.

As Covid  19 cases continue to increase and the mask shortage worsened, the CDC  said that masks can be reused and ,that homemade masks and scarfs could be used as a last resort by health care workers. This was a major change in CDC recommendations.Home made masks and scarfs can be used to protect the public as well, although that was not said by CDC.

Jeremy Howard,a Deep Learning specialist from Stanford, has posted an excellent review of the use and value of face masks by the general public to decrease COVID spread and describes widespread use by the public in many countries.See here

He gives links to sites with important information on how to clean masks and how to make masks at home from towels, t shirts etc. Some may worry about being accused of taking masks away from doctors and nurses if they wear a mask in public. Home made masks would alleviate that issue.

Covid 19  is spread by droplets by asymptomatic as well as symptomatic persons
Various kinds of masks decrease risk of spread
Masks can be made at home and worn in public  without shame .A great DIY project
Masks  protect others perhaps even more than they protect the wearer
It has been suggested that it would be unpatriotic for the public to wear masks.I suggest the opposite.
wearing masks is patriotic.An asymptomatic covid 19  infected person being in public exposing others to the disease is certainly not patriotic.
I am not recommending  to bid up prices of masks,No one wants to take masks away from HCWs.
 But if you already have masks on hand ,wear them .If not they really can be made at home and will offer some important protection . Yes, less than the properly fitted and correctly worn N 95 and less than surgical masks but significant protection nevertheless.
Bottom line wear masks in crowds (including grocery shoping)

Finally, imagine for a moment if only 25% of subway riders in New York (8 million riders per day) wore masks for the last 2 -3 weeks what the results might have been. Also imagine the potential benefit after we all come out emerge from sheltering in place how potentially important wide spread use of mask might be in decreasing the risk and/or impact of a second wave.

The following quite is from Scott Alexander writing on his blog slatestarcodex.com on 3/23/20 givig
a detailed analyzed on the research of various mask and the protection they provide;

. So should you wear a mask?

Please don’t buy up masks while there is a shortage and healthcare workers don’t have enough.

If the shortage ends, and wearing a mask is cost-free, I agree with the guidelines from China, Hong Kong, and Japan – consider wearing a mask in high-risk situations like subways or crowded buildings. Wearing masks will not make you invincible, and if you risk compensate even a little it might do more harm than good. Realistically you should be avoiding high-risk situations like subways and crowded buildings as much as you possibly can. But if you have to go in them, yes, most likely a mask will help.

In low-risk situations, like being at home or taking a walk, I mean sure, a mask might make you 0.0001% (or whatever) less likely to get infected. If that’s worth it to you, consider the possibility that you might be freaking out a little too much about this whole pandemic thing. If it’s still worth it, go for it.

You are unlikely to be able to figure out how to use an N95 respirator correctly. I’m not saying it’s impossible, if you try really hard, but assume you’re going to fail unless you have some reason to think otherwise. The most likely outcome is that you have an overpriced surgical mask that might make you incorrectly risk-compensate.

If you are a surgeon performing surgery, bad news. It turns out surgical masks are not very useful for you (1, 2)! You should avoid buying them, since doing so may deplete the number available for people who want to wear them on the subway.
Here is a quote from a blog post by Tomas Pueyo entitled "Coronovirus:The Hammer and the Dance"which has attracted considerable interest.Here is the link.https://medium.com/@tomaspueyo/coronavirus-the-hammer-and-the-dance-be9337092b56

Pueyo considers masks part of the solution." (my undelining)
"the massive impact of policies like those of Singapore or South Korea:
  • If people are massively tested, they can be identified even before they have symptoms. Quarantined, they can’t spread anything.
  • If people are trained to identify their symptoms earlier, they reduce the number of days in blue, and hence their overall contagiousness
  • If people are isolated as soon as they have symptoms, the contagions from the orange phase disappear.
  • If people are educated about personal distance, mask-wearing, washing hands or disinfecting spaces, they spread less virus throughout the entire period."

(note the blue and orange phase references refer to charts in his article)

Wednesday, March 25, 2020

Do ARBs and ACEis make COVID 19 infection worse?

A recent article in the BMJ raised concern that drugs that inhibit parts of the RAAS system might be harmful to patients infected with the new novel corona virus  known as COVID 19.

 Coarse grain epidemiologic data from the Wuhan outbreak indicated that one of the risk factors for bad outcomes was hypertension.It was then hypothesized that the increased mortality might be due to the subset of hypertension patients who were taking ARBs or ACEi as those may increase levels of ACE2 which has been shown in animals and possibly humans and ACE2 is the receptor for both SARS-CoV and SARS-COv2. So with more ACE2 would the results be a higher viral load?

On the other hand in an animal model of SARS-COV ARMS seems to reduce lung injury.

All this and a detailed recitation of the RAAS system as it relates to Corona viral infection can be found in the link found at the end of this post as can the citation for the BMJ article..That link is an article by Dr. GM Kuster et al published March 20 2020 in the European Heart Journal which reaches this conclusion:

In conclusion, based on currently available data and in view of the overwhelming evidence of mortality reduction in cardiovascular disease, ACE-I and ARB therapy should be maintained or initiated in patients with heart failure, hypertension, or myocardial infarction according to current guidelines as tolerated, irrespective of SARS-CoV2. Withdrawal of RAAS inhibition or preemptive switch to alternate drugs at this point seems not advisable, since it might even increase cardiovascular mortality in critically ill COVID-19 patients.
This is in agreement with a recent statement made by ACC/AHA.See herehttps://www.acc.org/latest-in-cardiology/articles/2020/03/17/08/59/hfsa-acc-aha-statement-addresses-concerns-re-using-raas-antagonists-in-covid-19


Thursday, March 19, 2020

Can Asymptomatic persons positive for covid-19 transmit disease

I believe we need to act as if they can.

A report from the chief epidemiologist from China's CDC in early March seemed to be reassuring.
Dr. Z.Wu speaking on an online conference on March 6 told the audience that transmission from presymptomatic people is rare and indicated that the  rate was 1-5% among person in close contact with infected patients.

Subsequent reports and consideration of foci of  rapid spread, (e.g. the Boston Biogen conference,the ill- fated cruise of the Diamond princess) suggest presymptomatic transmission may not be rare.

Japanese researchers found 634 of the 3711 passengers on the Diamond Princess tested positive and estimated 17.9 percemt were asymptomatic .

Using data from Tiajin China  Dutch researchers used a mathematical model to estimate from Tiajin  that the proportion of pre-symptomatic transmission was 62% ( 95% CI 50-76 %)

Note- these two analyses give estimates  and not actual proven head counts of instances of spread from person without symptoms

Viral counts are higher in the nose and throat and peak earlier in covid 19 infections than was the case with SARS so that it seems very plausible that a pre-symptomatic person could transmit disease.

 Further, even if the outer bounds of these estimates are still overestimates  the likelihood of pre-symptomatic spread  raises  major questions regarding  some of the current guidelines and  advice from public health experts.

If exposed health care workers are allowed to return to work based on history of no symptoms and there is asymptomatic spread then other workers and patients are at risk.

Early on in the U.S, public health experts discouraged the use of masks by the general public at times with an apparently self contradicting argument that 1) masks don't really work and 2)masks should be reserved for doctors and nurses.

 Of course, Surgical masks are not as effective a N-95 units but since viruses spread by droplets , masks offer some protection. Telling the public  that masks don't work does not seem to be very good advice and that position seems to have largely walked back.

 Early on US public health spokespeople  downplayed possible pre-symptomatic transmission but now that has changed.In fact Dr. Scott Gottlieb said "We know there is asymptomatic spread".Further, in a 3/18/200 tweet he suggested that if the youth who are ignoring efforts to be socially distant they should be required to wear masks"

I believe also that high risk people who for good reason must venture into crowded areas  ( e.g. groceries) should wear masks. I know I am- being at high risk by reason of age.

Friday, February 28, 2020

What do Left bundle banch block and traditional right ventricular cardiac pacing have in common?

Although it was demonstrated at least as early as 1989 by CL Grines et al (1) that left bundle branch block (LBBB) could cause significant functional impairment of the left ventricule (LV), clinical description and  general recognition of a LBBB cardiomyopathy as a clinical entity would require a decade or more.

Pacing the apex of the right ventricule was the default method for cardiac pacemaker implantation for many years and  the path to recognition of a right venricular pacing induced cardiomyopathy and a better way to pace was neither short nor particularly straight.

In 2005 (Blanc et al ) and in 2013 (Vaillant) reports appears describing a dilated cardiomyopathy apparently induced by LBBB that in some instances were significantly reversed by cardiac resynchronization treatment (CRT).Blanc wrote "long standing LBBB may be a newly identified reversible cause of cardiomyopathy."

Further proof was offered by Barot et al (2017) in the form of a  retrospective followup report.Thirteen of 94 LBBB patients with normal cardiac function (normal ejection fraction (EF) and no evidence of coronary artery disease developed a significant reduction in LV function over a variable time.

Not only is LBBB dyssynchronopathy heart failure now recognized it has become apparent that the usual heart failure meds do not seem very effective. In 2015, NC Wang et al reported the lack of response  to medical therapy in 32 LBBB patients with new onset LBBB-associated idiopathic non-ischemic cardiomyopathy (NICM) and that "a high percentage were super-responders [to CRT]."

James Daubert and Edward Sze (3)argued in 2018 that the then current guidelines for implanting CRT require at least 3 months of guide-line directed therapy (GDMT) before implantation but there are no randomized clinical trials showing efficacy of medications and suggested that CRT should be  considered for first line therapy rather than GDMT as many  (most) symptomatic patients with LBBB do not respond to GDMT.

Since the early 1990s CRT has become an important treatment for heart failure  with reduced ejection fraction (HFrEF) and delayed intra-ventricular conduction with the greatest benefit in those patients with LBBB.CRT traditionally has meant right ventricular pacing plus pacing the left ventricle from a vein on the surface of the left ventricle accessed through the coronary sinus.This is referred to as Bi-V.  or biventricular pacing.More recently His Bundle pacing (HBP) has been suggested as being as good  and perhaps better than Bi-V or at least as an alternative in cases in which the coronary sinus lead could not be placed.In cases in which the mechanical dyssynchrony is caused by an electrical problem an electrical "fix" seems necessary.HBP would seem to be the best fix being more physiological than Bi_V pacing .

Placing a pacing lead in the apex of the right ventricle was standard procedure for bradycardia indications for many years before EP cardiologists raised the question and then gathered evidence and finally  concluded that in fact RV pacing could lead to significant loss of synchrony in the LV which   resulted in heart failure in a significant number of patients

The similarities of the EKG in right apical pacing and LBBB certainly suggested possible functional impairment from RV pacing.Cardiologists were interested in some alterenative pacing method to avoid the harm that was becoming evident in RV pacing but no good alternative presented itself, at least not until HBP.Reports of septal pacing in place of apical pacing gave conflicting results.

As effective as traditional CRT (i.e. Bi-v) is some 30 % plus of patients with HF do not response while some seem to be "super-responders".Patients with narrow QRS complexes do not respond and those with a LBBB pattern are more likely to respond but all patients with a similar LBBB pattern do not all respond to the same degree nor do they necessarily have the identical patern of LV electrical activation.All patients with an EKG designation of LBBB are not created equal.

The typical pattern of LV contraction described in LBBB is the following:

The interventricular septum moves quickly to the left in early systole (in the isovolumic contraction phase, i.e before aortic valve opens).The LV lateral wall is pushed  outward and finally the electrical impulse traveling through myocytes reaches the lateral left wall area and it contracts pushing  the septum to the right.

The initial left shift of the septum is mainly  the result of the electrical impulse traveling from right to left (the opposite of the normal situation) and also from the pressure difference between the RV and LV as the RV contracts before the delayed LV contraction. This initial septal shift is called septal flash or septal beak and can be seen on M mode echo as well as on speckletracking echo.

Calle et al (2 ) have proposed that this septal flash may be the key to what "true LBBB" is- meaning the pattern of dyssynchrony that is responsible for the functional impairment and the pattern most "fixable" by CRT and by HBP as regards both LBBB and right apical pacing induced dysfunction.

Various other echo criteria have been proposed as the preferred measure to assess dyssynchrony and response to CRT without general agreement. About 50% of patients with the EKG pattern of LBBB are shown to have the septal flash and the associated dysfunctional out-of-sync LV contraction.

The septal flash indicates that the septum is activated from right to left initiating a sequence of dyssynchronous ventricular segmental contractions and relaxations that are deleterious to ventricular function and may result in remodeling and ultimately heart failure with reduced ejection fraction and is often reversible to varying degrees with CRT either by HBP or Bi-V.

So would CRT be expected to be useful in patients with RBBB since the septal  activation is from left to right.In theory- no but Sharma ( 3) et al have reported significant clinical improvement
 in some RBBB heart failure patients treated with HBP.Perhaps right to left septal activation ( as indicated by septal flash) is not a necessary condition for there to be improvement from CRT but I doubt one would see a super-response and the mechanism of benefit may relate more to improved atrial-ventricular synchrony improvement  and not correction of an abnormal septal activation.

1) Grines, Cl et al Functional abnormalities in isolated left bundle branch block.The effect of interventricular asynchrony. Circulation  1989 79 845-853

2)Calle,D et al, Septal Flash :At the heart of cardiac dyssynchrony. Trends in Cardiovacsular Medicine2019,14,9

3)Sze,E and Daubert,JP Left bundle blck induced left ventricular remodeling and its potential of reverse remodeling. J Intv Card Electrophysiol 52 (3) 343-352, 2018

Tuesday, January 28, 2020

How Will "medicare for alll" be like the military industrial complex?

The following quotes are from the blog "on health care technology" written by Margalit Gur-Arie:

"Go ask Northrup Grumman or Lockheed Martin or General Dynamics or even Boeing or Booz Allen or any other “beltway bandit” how getting money from the Feds really works. There are well-greased revolving doors between the Pentagon and its contractors. There are stock options and executive positions for high ranking Federal employees. There are 535 people in Congress responsible for allocating budgets, and all 535 are for sale. Most of this infrastructure is already in place for health care too and building the HHS Heptagon shouldn’t take very long. The American President has little to no power over Federal spending, and even less so when it comes to large procurement contracts, as the current occupant of the White House discovered the hard way, during the Lockheed F-35 kerfuffle....

Clearly large health systems will survive and thrive under a Medicare For All law, but how about private health insurance? Future President Bernie says they will all be banned. Is that so? Currently a full third of Medicare beneficiaries are insured and “managed” by a handful of large private health insurers. Medicare is paying those private contractors fixed amounts of money per head for their services. Medicaid is doing the same for most of its beneficiaries, and all military health insurance (TRICARE) is contracted out to the usual suspects. Basically, the vast majority of people covered by public insurance, are really insured by gigantic insurance corporations. Fact: under the hood, taxpayer funded health care is the bread and butter of private health insurance companies."

So her analysis suggests very little difference at all.

The well known revolving door in regard to government and the defense industry is paralleled by the what goes on in the health care and pharmaceutical industry.See here 

Monday, December 16, 2019

Important changes happening(and happened) in Med School Education what is it about?

Drs. Accad and Koka  discuss  major changes in Medical school education with Dr. Stanley Goldfarb.See here for the podcast.

Are the changes in the medical school curriculum designed to develop social and political advocates rather than well trained physicians?Dr. Goldfarb argues that it is.

The changes are all about population medicine,some thing I have blogged about often before see here.

Courses about climate and medical conditions are already on the curriculum of several medical schools ( see here ).One school mentioned in the linked article actually giving instructions on how to write op-eds about climate change supply a concrete example of Goldfarb's argument.Classes on
environmental justice are also appearing on the schedule.

The degree to which a progressive view point is often part of primary,high school and college education should make it no surprise that med school students are actually requesting courses
in social and environmental justice.

Friday, December 13, 2019

Should journals always report fragility index on a clinical trial.

Interesting article in December 2019 Circulation.(See here.) that discusses the "robustness" of a number of cardiovascular disease trials.

A  purported measure of robustness is the Fragility Index (FI) which is the number needed to move from the non-event group to the event group to turn a statistically significant finding into a non-significant one. A FI of 1 would mean that if one subject was moved from the event to the non event group there would no longer be a significant  difference.

A related concept is  the comparison of the FI to the number of subjects lost to follow up. The trial's results would be considered less robust if the number lost is greater than the FI.

Ridgeon et published a review of 56 RCTs in critical care treatment topics.The median FI was 2 and slightly greater that 40% of trials had a FI of one or less.So does that suggest that clinical guidelines based entirely or in part on those low FI studies are built on shifting sands?

But wait, listen to this criticism of the concept of FI by Dr. F.Perry Wilson before rushing to trash a RCT simply because the FI is too low. Wilson shifts the problem to one of having too much reliance on the p value in the first place.

1)Ridgean EE et al Crit. Care Med 2016,vol 44 ,1278