Without evidence of benefit, an intervention should not be presumed to be beneficial or safe.

- Rogue Medic

NIH clinical trial of remdesivir to treat COVID-19 begins

     

The University of Nebraska Medical Center (UNMC) in Omaha is the receiving facility for Americans repatriated with suspicion of infection with COVID-19 (COronaVIrus Disease 2019). UNMC will be enrolling patients in a double-blind study comparing standard treatment with an investigational antiviral drug against standard treatment with a placebo.[1]

The start of this study does not mean that anyone knows, or even has has good reason to believe, that remdesivir is an effective treatment in humans for COVID-19. Remdesivir is an investigational antiviral that has been tested on other coronaviruses, but has not been shown to be effective in treating humans. Remdesivir was also studied as a possible treatment for ebola virus (a filovirus), and was found to be effective in other species, but was not found to be effective in humans.
 

About Remdesivir Remdesivir is an investigational nucleotide analog with broad-spectrum antiviral activity – it is not approved anywhere globally for any use. Remdesivir has demonstrated in vitro and in vivo activity in animal models against the viral pathogens MERS and SARS, which are also coronaviruses and are structurally similar to COVID-19. The limited preclinical data on remdesivir in MERS and SARS indicate that remdesivir may have potential activity against COVID-19.

This is an experimental medicine that has only been used in a small number of patients with COVID-19 to date, so Gilead does not have an appropriately robust understanding of the effect of this drug to warrant broad use at this time.[2]
 

What is the most common symptom?

There does not appear to be any symptom that is always present.

Travel to China, or to the region of China where COVID-19 was first identified, or contact with people who were in contact with people known to be infected with COVID-19 are often present, but not always. Cough and fever appear to be the most common symptoms, but that are also not always present.

The full text of the first case in the US is worth reading. A 35 year old male with a cough and no fever (37.2°C – 99.0°F), but he felt like he had a fever, went to an urgent care clinic, based on his symptoms and news reports. He did not test positive for anything else that is screened for. A sample was sent to the CDC (Centers for Disease Control and Prevention). He was treated with a variety of medications. A day after he was treated with remdesivir, he began to improve. Was he just getting better on his own? We do not know, but the research at UNMC should help to answer that question. Given the number of patients, and the already known distribution of patients, there should be plenty of participants, unless someone decides to promote the political witchcraft of “compassionate use”. Then we may never know and remdesivir could become the blood-letting of the 21st century.

Footnotes:

[1] NIH clinical trial of remdesivir to treat COVID-19 begins Study enrolling hospitalized adults with COVID-19 in Nebraska.
Tuesday, February 25, 2020
National Institutes of Health (NIH)
News release

and –

NIH Clinical Trial of Remdesivir to Treat COVID-19 Begins Study Enrolling Hospitalized Adults with COVID-19 in Nebraska February 25, 2020
National Institute of Allergy and Infectious Diseases (NIAID)
News release

[2] COVID-19 Gilead Sciences Update On The Company’s Ongoing Response To COVID-19
Gilead Sciences
Article

[3] First Case of 2019 Novel Coronavirus in the United States.
Holshue ML, DeBolt C, Lindquist S, Lofy KH, Wiesman J, Bruce H, Spitters C, Ericson K, Wilkerson S, Tural A, Diaz G, Cohn A, Fox L, Patel A, Gerber SI, Kim L, Tong S, Lu X, Lindstrom S, Pallansch MA, Weldon WC, Biggs HM, Uyeki TM, Pillai SK; Washington State 2019-nCoV Case Investigation Team.
N Engl J Med. 2020 Jan 31. doi: 10.1056/NEJMoa2001191. [Epub ahead of print]
PMID: 32004427

Free Full Text from N Engl J Med.

[3] “Right to try” laws create tremendous legal uncertainties; FDA expanded access preferable The Goldwater Institute and the Kochs pushed “right to try” laws in an attempt to get rid of FDA oversight of access to investigational drugs. Instead, they created tremendous legal uncertainties, making the FDA’s expanded access program preferable for all.
Jann Bellamy
January 17, 2019
Science-Based Medicine
Article

.

Happy Darwin and Lincoln Day 2020


Happy Lincoln-Darwin Day!
 
Today is the birthday of two people considered enemies by the American slavery belt – Charles Darwin and Abraham Lincoln. The slavery belt was so afraid of Lincoln that most of the slave states seceded before Lincoln took office as president.

Charles Darwin wrote a book that exposed the slavery of human beings as immoral. The slaves were just as human as every slave owner. Bible quotations in defense of slavery were regularly provided by slave owners to justify their immorality, but it was not working as well as it used to. To be fair, many of the Founding Fathers opposed slavery, but this was a compromise that will always stain the Constitution. There was even an agreement in the Constitution to allow the importation of slaves at least until 1808.
 

The Migration or Importation of such Persons as any of the States now existing shall think proper to admit, shall not be prohibited by the Congress prior to the Year one thousand eight hundred and eight, but a tax or duty may be imposed on such Importation, not exceeding ten dollars for each Person.[1]

 

There was enough opposition to the importation of slaves that a law prohibiting importation went into effect the first day possible – January 1, 1808.

Opponents of Lincoln continue to make excuses for the treason of the slave states that seceded and made war on the United States of America.

Opponents of Darwin continue to make excuses for rejection of biology, even though genetics and evolution are essential for the understanding of biology. Denial of science has become a tenet of Creationist sects.

Currently the most popular method of denying science is the one made notorious by the exposure of private documents of the cigarette industry. Create the appearance of scientific doubt and scientific controversy, even though the only doubt and controversy is about minor details, rather than the broad conclusions.
 

The most important type of story is that which casts doubt in the cause and effect theory of disease and smoking. Eye-grabbing headlines should strongly call out the point[2]

 

 

Doubt is our product next hit since it is the best means of competing with the “body of fact” that exists in the mind of the general public. It is also the means of establishing a controversy. Within the business we recognize that a controversy exists. However, with the general public the consensus is that cigarettes are in some way harmful to the health. If we are successful in establishing a controversy at the public level, then there is an opportunity to put across the real facts about smoking and health. previous hit Doubt is also the limit of our ” product.” Unfortunately, we cannot take a position directly opposing the anti-cigarette forces and say that cigarettes are a contributor to good health. No information that we have supports such a claim .

Truth is our message because of its power to withstand a conflict and sustain a controversy. If in our pro-cigarette efforts we stick to well documented fact , we can dominate a controversy and operate with the confidence of justifiable self-interest [italic emphasis added]. {2111.01, pp. 4, 5}[3]

 

The point was to create the appearance of honesty, without the substance. This method is used by a lot of other science denialists – anti-vaxers, climate change deniers (both those who deny that climate change is real and those who claim that human activity is not responsible for the dramatic acceleration of global warming), flat earthers, alternative medicine promoters, anti-GMO activists, anti-abortion activists, anti-equality activists, geocentrists, et cetera.

Reality is their enemy.

Reality will always be their enemy.

Footnotes:

[1] Article 1 Section 9
U.S. Constitution
Link to Article 1 Section 9 at constitution.net

[2] Tobacco Explained – The truth about the tobacco industry …in its own words
World Health Organization
Page 11/79 on the pdf counter, but marked as page 7 on the page
Free Full Text in PDF format from WHO
 

Carl Thompson from Hill and Knowlton writes a letter on the best angles for the
industry magazine, Tobacco and Health Research:
“The most important type of story is that which casts
doubt in the cause and effect theory of disease and
smoking. Eye-grabbing headlines were needed and
“should strongly call out the point – Controversy! Contradiction! Other Factors! Unknowns!” 31 (Hill and
Knowlton, 1968)

 

[3] Using Cigarette Ads to Counter Health Information
The Cigarette Papers
Chapter 5 Public Relations in the “Safe” Cigarette Era
Resisting Government Regulation: Advertising Campaigns
Pages 190-191
University of California Press
Link to book with search for “Doubt is our product”

.

Happy Friday the 13th

One of the Most Holy Days of the Church of Anecdote and Confirmation bias is here.

Will it be quiet? Oops, the utterance of the word Quiet can turns any day into a Friday the 13th for some celebrants of this religion, at least for those who work in EM/EMS (Emergency Medicine/Emergency Medical Services).

Are these superstitions unreasonable? Absolutely, but try explaining that to someone who rejects reason.

How do you reason with people who reject reason? Presenting large quantities of objective evidence is not going to matter to believers, because their self-worth depends, to some extent, on protecting themselves from being reasonable.

A coincidence is a remarkable concurrence of events or circumstances that have no apparent causal connection with one another. The perception of remarkable coincidences may lead to supernatural, occult, or paranormal claims. Or it may lead to belief in fatalism, which is a doctrine that events will happen in the exact manner of a predetermined plan.

From a statistical perspective, coincidences are inevitable and often less remarkable than they may appear intuitively. An example is the birthday problem, which shows that the probability of two persons having the same birthday already exceeds 50% in a group of only 23 persons.[1] [1]

Uncountable numbers of unrelated events happen at apparently the same time. Since time itself is relative, the point of reference of the observer can be a factor in the appearance of coincidence. For example, thunder will be heard by a person at the same time the person sees lightning, while a mile away, a person sees the lightning 5 seconds before hearing the thunder. The thunder and lightning have the same cause, but the lightning and the thunder separate by even more time, from the perspective of even more distant observers.

The lack of perspective about observations has led people to develop more superstitions about coincidences than have been documented.

Casinos depend on superstition.

You have a system? Excellent. Come and apply your system to our games of chance. We will take your bets.

Casinos will not just take just your bets. Casinos will take trillions of dollars of bets, because they have arranged the odds to be, at least, slightly in their favor.

Do you wait for someone to put all of their money into a slot machine, then take their seat, expecting that the machine is overdue to pay out?

Casinos pay millions of dollars for famous people to perform on stage to draw you in to use that kind of system. The Casino will take your bet. Your money will help to pay even more for expensive entertainers.

You count cards?

Brilliant! The dealer, or a manager, is also counting cards and trained to recognize when someone is using a betting system based on card counting. The cameras, which watch everything happening at the tables, are also helping to track your habits. The cameras will also get high quality images of you, which casinos share as part of their countermeasures. Card counting is not illegal, but the casino can do a lot to keep the odds in the favor of the casino.

Roulette games have systems, as well. Likewise, the casinos want you to bet your money on your systems. They have bills to pay and your money is just a drop in the bucket to the casinos.

You don’t believe in coincidences?

Companies make trillions of dollars off of your belief. Your belief is their business and their business is profitable.

However, if you want to get better at recognizing the biases you have, challenge yourself to bets on the outcomes of your beliefs. It doesn’t have to be money. You can bet doing something you don’t want to do against doing something you do want to do, based on whether you are right about something you believe.

Write down what you believe/believe will happen. Write down your criteria for winning/losing. Don’t make excuses for fudging the criteria. Maybe doing something that you should do, but really don’t want to do. Think of how much you will accomplish – if you are honest with yourself and you set your bets up objectively.

Footnotes:

[1] Coincidence
Wikipedia
Web page

.

Do Emergency Physicians Intubate Often Enough to Maintain Competency?

 

    There is a study of the frequency of intubation among emergency physicians in the current Annals of Emergency Medicine. This study is accompanied by a discussion, which unfortunately does not question the assumption that intubation improves outcome. There is very little evidence to suggest that intubation improves outcomes. That evidence is only using paramedics with the highest success rates – much higher than your average paramedic.

 
Greater intubation experience in paramedics is associated with improved patient outcomes2; does a similar relationship exist for emergency physicians?[1]
 


Image credit.

The unquestioned assumption is that excellent intubation performance improves outcomes, rather than that excellent intubation performance causes less harm than average intubation performance, or below average performance. We do not have any good evidence to support the wishful thinking that paramedics, or even much more experienced emergency physicians, improve outcomes by intubating patients. We just assume this, because we don’t really want to know. If we decide to be honest and actually find out the effect of intubation, how will we handle it if the results show that we are harming more patients than we are helping?

The Cardiac Arrhythmia Suppression Trial was only started because the proponents of the different antiarrhythmics (encainide, flecainide, and moricizine) wanted to prove that their drug was better than all of the rest. They even agreed to include a placebo arm, although the doctors did not like the idea of depriving patients of such beneficial treatment.

 
CONCLUSIONS: There was an excess of deaths due to arrhythmia and deaths due to shock after acute recurrent myocardial infarction in patients treated with encainide or flecainide.[2]
 

People who had frequent ectopic heart beats – PVCs (Premature Ventricular Contractions) after a heart attack were more likely to die than people who did not have frequent PVCs. The obvious solution – the equivalent of intubation and blood-letting – was to give drugs that will get rid of the PVCs. The problem is that the PVCs were not the problem. The PVCs were just a sign of the problem. The drugs made the actual problem with the heart worse, while making the heart appear to be better. The same is true of blood-letting and may be true of intubation. Abundant evidence for the obvious benefits of blood-letting are quoted in the footnotes.[3]

If intubation is harmful, do we want to know?

If intubation by the average paramedic is harmful, do we want to know?

If intubation by the average emergency physician is harmful, do we want to know?

It isn’t as if we take intubation seriously. If we did take intubation seriously, we would practice much, much more than we do. In stead, we make excuses for failing to practice something that we claim is life-saving, because we are too arrogant to admit that practice is important to develop and maintain any skill.

Practicing on even the most basic mannequin should be done before every shift, whether you are a paramedic or an emergency physician. Unless you have a 99%, or better, success rate on hundreds of patients.

Footnotes:

[1] Intubation by Emergency Physicians: How Often Is Enough?
Kerrey BT, Wang H.
Ann Emerg Med. 2019 Dec;74(6):795-796. doi: 10.1016/j.annemergmed.2019.06.022. Epub 2019 Aug 19. No abstract available.
PMID: 31439364

The article above is commentary on the article below:

Procedural Experience With Intubation: Results From a National Emergency Medicine Group.
Carlson JN, Zocchi M, Marsh K, McCoy C, Pines JM, Christensen A, Kornas R, Venkat A.
Ann Emerg Med. 2019 Dec;74(6):786-794. doi: 10.1016/j.annemergmed.2019.04.025. Epub 2019 Jun 24.
PMID: 31248674

[2] Mortality and morbidity in patients receiving encainide, flecainide, or placebo. The Cardiac Arrhythmia Suppression Trial.
Echt DS, Liebson PR, Mitchell LB, Peters RW, Obias-Manno D, Barker AH, Arensberg D, Baker A, Friedman L, Greene HL, et al.
N Engl J Med. 1991 Mar 21;324(12):781-8.
PMID: 1900101

Free Full Text from N Engl J Med.

[3] Blood-Letting
Br Med J.
1871 March 18; 1(533): 283–291.
PMCID: PMC2260507
 

Physicians observed of old, and continued to observe for many centuries, the following facts concerning blood-letting.

1. It gave relief to pain. . . . .

2. It diminished swelling. . . . .

3. It diminished local redness or congestion. . . . .

4. For a short time after bleeding, either local or general, abnormal heat was sensibly diminished.

5. After bleeding, spasms ceased, . . . .

6. If the blood could be made to run, patients were roused up suddenly from the apparent death of coma. (This was puzzling to those who regarded spasm and paralysis as opposite states; but it showed the catholic applicability of the remedy.)

7. Natural (wrongly termed ” accidental”) hacmorrhages were observed sometimes to end disease. . . . .

8. . . . venesection would cause hamorrhages to cease.
 

.

Does Room Air Reduce Mortality Among Term Neonates Requiring Respiratory Support at Birth?

     

The title of this meta-analysis suggests that it is important for us to have evidence in order to withhold treatments that are based on assumptions and anecdotes, rather than based on evidence. We should not even suggest this. Fortunately, the neonatal resuscitation guidelines have recommended not using the assumption-based and anecdote-based treatment since 2010.

 

Before 2000, resuscitation guidelines recommended 100% Fio2 for newborn respiratory support.6 However, hyperoxemia caused by high Fio2 results in the formation of free radicals, which can damage the lungs, brain, eyes, and other organs.7 Hypoxemia may also lead to harm. Literature in the early 2000s suggested no harm with room air resuscitation in term neonates, but also potentially an improvement in short-term mortality.8 In accordance with this literature, in 2010 and 2015 ILCOR recommended using room air for the initial resuscitation of term neonates.9, 10 [1]
 

The authors of this summary of the meta-analysis qualify this meta-analysis with a list of the weaknesses of the research. This is important for every analysis of research, but is it relevant, when there is no good reason to recommend the traditional intervention?  

According to these results with low evidence certainty, room air reduces short-term mortality compared with 100% Fio2 among term neonates requiring respiratory support at birth. Despite the low-quality evidence, these results are consistent across studies with low heterogeneity. The effect of intermediate Fio2 levels is not known and may benefit from further study. [1]
 

These are not reasons to reconsider, or oppose, the withholding of any treatments that are based on assumptions and anecdotes, rather than based on evidence.

The burden of proof is on those promoting any intervention. In the absence of valid evidence, we should limit ourselves to interventions that are supported by high quality evidence.

For epinephrine in cardiac arrest, there is no high quality evidence of benefit. The highest quality evidence is evidence of harm from epinephrine. The same is true for amiodarone, ventilation in cardiac arrest not due to a respiratory problem, furosemide in ADHF/CHF (Acute Decompensated Heart Failure/Congestive Heart Failure), and many other treatments we provide to patients, but definitely not for the benefit of patients.

We need to stop putting patients last in treatment decisions. The neonatal resuscitation guidelines are correct in their rejection of supplemental oxygen for neonatal resuscitation and the guidelines should not be changed.

Footnotes:

[1] Does Room Air Reduce Mortality Among Term Neonates Requiring Respiratory Support at Birth?

Brit Long, MD (EBEM Commentator), Michael D. April, MD, DPhil (EBEM Commentator) Department of Emergency Medicine, San Antonio Uniformed Services Health Education Consortium, Fort Sam Houston, TX

Annals of Emergency Medicine

October 2019, Volume 74, Issue 4, Pages 509–511

DOI:&nbps;https://doi.org/10.1016/j.annemergmed.2019.03.017

Free Full Text from Annals of Emergency Medicine. .

Happy Full Moon Friday the 13th


Technically, the full moon is not until 00:33 – 33 minutes after the end of Friday the 13th, so that may help the superstitious to feel better, since these superstition events are not actually coinciding – pitting twice as many Gods against the superstitious (a double whammy). Or the superstitious may feel worse, because they now have two days in a row of the Gods conspiring against them. The reality is that only their own beliefs conspire against them. it is all in the heads of the believers.

Even when someone does claim to come up with some evidence to support their beliefs, those conclusions are not supported by higher quality research.
 

In conclusion, Friday the 13th appears to be dangerous for some women. Since Friday falls on the 13th day of the month only twice a year on average, prospects for significant public health gains are limited. However, the risk of death for women who venture into traffic on this unlucky day is higher by 63%, and it should be possible to prevent one-third of the deaths occurring on this particular day. Even then, the absolute gain would remain marginal, since only one death per 5 million person-days could be prevented.[1]

 

The total number of deaths is small. Drawing that conclusion, based on a small sample size is a problem. In order to be able to come up with larger numbers, to minimize the effects of the small sample size, other researchers looked at the motor vehicle collisions, rather than just fatal motor vehicle collisions. The assumption that the cause of the fatalities was anxiety, produced by superstition among the drivers is projecting a lot onto the drivers – without any evidence to support this supposed cause.

It should not be a surprise that the results of a much larger sample size contradicts the assumptions based on the much smaller sample.
 

Conclusion:
We conclude that, in the Finnish traffic accident statistics for 1989–2002, females have not incurred more injury (or fatal) road traffic accidents on Fridays the 13th than expected, as a driver, bicyclist or pedestrian. We suggest that Näyhä’s contradicting result on fatalities is due to different sampling, non-optimal setting and chance in a fairly small data. However, this does not imply a nonexistent effect on accident risk as no exposure-to-risk data [18] are available. People who are anxious of “Black Friday” may stay home, or at least avoid driving a car. The only relevant data [4], suggesting a small decrease in highway traffic, is rather limited and should be confirmed with more extensive research.[2]

 

The law of small numbers is an attempt to expose the mistake of extrapolating from small numbers as if the small numbers are representative. Small numbers are misleading. Small numbers are often used to promote ideas that are not supported by adequate numbers – such as the claims that epinephrine improves cardiac arrest outcomes that matter, or that amiodarone improves cardiac arrest outcomes that matter.[3]

Footnotes:

[1] Traffic deaths and superstition on Friday the 13th.
Näyhä S.
Am J Psychiatry. 2002 Dec;159(12):2110-1.
PMID: 12450968

[2] Females do not have more injury road accidents on Friday the 13th.
Radun I, Summala H.
BMC Public Health. 2004 Nov 16;4:54.
PMID: 15546493

Free Full Text from PubMed Central.

[3] Chapter 10
The Law of Small Numbers

Thinking, Fast and Slow
Daniel Kahneman
2011
Wikipedia page

.

Safety and Effectiveness of Field Nitroglycerin in Patients with Suspected ST Elevation Myocardial Infarction

 

Is prehospital use of NTG (NiTroGlycerin; GTN GlycerylTriNitrate in Commonwealth countries) safe for treating prehospital suspected STEMI (ST segment Elevation Myocardial Infarction) patients?

The evidence is limited, but does not suggest that prehospital NTG produces enough harm to discourage use in suspected STEMI. These researchers looked at the emergency department assessments of patients following prehospital NTG for suspected STEMI.  

Despite the theoretical risk, the limited retrospective studies of NTG in the prehospital setting for multiple indications suggest that the medication is safe.(10-13) However, with regard to NTG use for STEMI, the AHA International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care concluded that there was not enough evidence to determine the benefit or harm of out-of-hospital use of NTG.(14) Given the high false positive rates for STEMI identified in the field, an additional concern is that many patients treated with NTG for presumed STEMI will ultimately have an alternate etiology for their pain.(15, 16) Therefore, it is not clear that the benefits outweigh the risks of administering NTG to all patients with suspected STEMI in the field.[1]
 

This paper helps to show the safety of prehospital NTG for suspected STEMI, providing evidence that blood pressure changes were similar in suspected STEMI patients with an SBP (Systolic Blood Pressure) of 100, or higher, regardless of whether they were treated with NTG. The study is a retrospective chart review, so we do not know why some of the patients were not treated with NTG.

One reason mentioned, but not discussed, is that only 22% (96 of 440) suspected STEMI patients not treated with NTG are documented to have had pain, but there is no information on the type of pain or other cardiac symptoms of the patients. Were the paramedics avoiding treating atypical chest pain, such as pressure, heaviness, gastric discomfort, difficulty breathing, et cetera? We do not know. Was only chest pain being documented, rather than shoulder, or arm, or jaw, pain? We do not know. Did the pain resolve prior to EMS arrival? We do not know. Were the paramedics correctly recognizing when the machine interpretation of the ECGs (ElectroCardioGrams) were wrong? We do not know.

The median Initial Pain Score is documented as 8, with an IQR (Inter-Quartile Range) of 5-9 for those treated with NTG. For those not treated with NTG the Initial Pain Score is documented as 0, with an IQR of 0-0. We do not know the Initial Pain Score of those who did have pain, but were not treated with NTG. All of these patients were in an IQR that was not documented in the paper. The good news is that the suspected STEMI patients not treated with NTG act as a control group, although possibly with important differences that are not discussed in the paper.

Click on the image of the LA County protocol to make it larger.[2]

What about the 17% of suspected STEMI patients with SPB <100 mmHg who were treated with NTG?

Was medical command (California has certified MICNs [Mobile Intensive Care Nurses] providing medical command on the radio, with physicians available, as well) contacted for authorization to deviate from the protocol? If so, that is something that should be documented in the charts, which were reviewed for this paper. That information is not included in this paper. Those patients are much more interesting to me.

I do not object to using NTG to treat suspected STEMI with an SBP below 100 mmHg, but the authors seem to think that EMS should not even consider it. Do the outcomes of those patients support the approach of the authors? We do not know.

I suspect that the fears of bottoming out the blood pressure are very exaggerated, but it would be nice to have some evidence either way.

An important secondary end point was the differences between those with inferior/right ventricular STEMI, but treated with NTG.  

By vasodilating all blood vessels, and the venous system in particular, it causes a drop in blood pressure and preload. Thus, there is concern for precipitating hypotension in ACS involving the right ventricle.(1-3) Contraindications to the use of NTG, as outlined by the American Heart Association (AHA) Guidelines on the treatment of ACS, include right ventricular infarction.(4) This raises concern for use in inferior ST-segment elevation myocardial infarction (STEMI) in the prehospital setting, since many inferior STEMI result from proximal right coronary artery (RCA) occlusion and 50% involve the right ventricle.(3) Traditional 12-lead ECG is focused mainly on the left side of the heart and typically EMS protocols do not include acquisition of right-sided ECG leads. Further, in many systems, Basic Life Support (BLS) protocols allow for administration of NTG without differentiating the location of STEMI. There is also risk of other adverse events including bradycardia and cardiac arrest.(5-9)[1]
 

I have aggressively promoted the use of NTG for even hypotensive CHF/ADHF (Congestive Heart Failure/Acute Decompensated Heart Failure). Many physicians are not comfortable with that, even though the available evidence shows that aggressive IV NTG doubled the survival rate for these hypotensive patients. More research is needed on the use of NTG, especially in hypotensive patients.  

Further, we did not find an increased risk of hypotension among patients with proximal or mid RCA occlusions confirmed on coronary angiography. There are several possible reasons for our findings. First, while right ventricular involvement in inferior STEMI is common, hemodynamic instability is actually rare due to the right ventricle’s more favorable oxygen supply-demand ratio compared to the left heart and more extensive collateral flow.(3, 22) In addition, left heart occlusions may also involve the right ventricle and result in a preload dependent condition.(23-25) While limited by sample size, our results suggests that specifically avoiding NTG use in inferior STEMI, which is common in EMS systems, may be misguided. One quarter of the local EMS agencies in the state of California, for example, currently prohibit the use of NTG in inferior STEMI.(26) This analysis would benefit from additional study with a larger sample size and specific information about the infarct territory. Further studies are needed to determine which patients, in particular, are at increased risk for hypotension when treated with NTG.[1]
 

Perhaps NTG is also safe for treating patients with inferior ischemia and even right ventricular ischemia.

Footnotes:

[1] Safety and Effectiveness of Field Nitroglycerin in Patients with Suspected ST Elevation Myocardial Infarction.

Bosson N, Isakson B, Morgan JA, Kaji AH, Uner A, Hurley K, Henry TD, Niemann JT.

Prehosp Emerg Care. 2018 Dec 17:1-9. doi: 10.1080/10903127.2018.1558318. [Epub ahead of print]

PMID: 30556765

[2] Treatment Protocol: Chest Pain */ Acute MI

Reference No. 1244

LA County Paramedic Protocols

Los Angeles County Department of Health Services – Emergency Medical Services

Protocol

.

Association of ventilation with outcomes from out-of-hospital cardiac arrest

 

Does this study compare chest compressions with pauses for ventilation (regular CPR [CardioPulmonary Resuscitation]) against continuous chest compressions with no ventilations (compression-only CPR)?

Absolutely not.

This only compares compressions with pauses for good ventialtions against compressions with pauses for bad ventilations.

Will this be used to justify including ventilations in CPR, in spite of the absence of any valid evidence that ventilations improve outcomes?

Yes. It already has in the editorial about the study, published in the same issue.[1]

The authors of the paper were clear about the actual comparison in the discussion.
 

Why did so few patients in our study receive ventilation during CPR? Ventilation with a BVM device is a difficult skill to perform properly and must be practiced to maintain proficiency.22 The person performing ventilation must extend the neck, or place an oral airway, and/or perform a jaw thrust maneuver in order to maintain an open airway, a tight mask seal on the face must be maintained to prevent air from leaking around the mask, and the rescuer must then simultaneously squeeze the manual ventilator over 1 to 1.5 s. Our study showed no significant difference in the number of pauses between Group 1 and Group 2 patients (11 vs. 12 pauses). However, Group 2 patients received significantly more ventilations than Group 1 patients (8 vs. 3 ventilations). The study suggests that the rescuers in both Groups attempted ventilation about the same number of times per patient, but these attempts frequently did not result in lung inflation in Group 1 patients.[2]

 

In other words, this is a study of 30 compressions with a pause for 2 adequate ventilations to 30 compressions with a pause for 2 inadequate ventilations. This is important to know, but it has nothing to do with compression-only resuscitation.
 


 

Were the ventilations in the bad ventilation group going into the stomach? There are not a lot of possibilities, but not much of the ventilations were not going into the lungs or the ventilations were very shallow.

The authors do not mention if there is any difference in the rate of vomiting, aspiration, or other side effects expected from bad ventilation, between the groups.

The authors appear to be measuring the quality of ventilation, which is has never been shown to improve outcomes over compression-only resuscitation.

There is research showing that ventilations do not improve outcomes:
 

Cardiocerebral resuscitation improves survival of patients with out-of-hospital cardiac arrest.
Kellum MJ, Kennedy KW, Ewy GA.
Am J Med. 2006 Apr;119(4):335-40.
PMID: 16564776 [PubMed – indexed for MEDLINE]

Cardiocerebral resuscitation improves neurologically intact survival of patients with out-of-hospital cardiac arrest.
Kellum MJ, Kennedy KW, Barney R, Keilhauer FA, Bellino M, Zuercher M, Ewy GA.
Ann Emerg Med. 2008 Sep;52(3):244-52. Epub 2008 Mar 28.
PMID: 18374452 [PubMed – indexed for MEDLINE]

Minimally interrupted cardiac resuscitation by emergency medical services for out-of-hospital cardiac arrest.
Bobrow BJ, Clark LL, Ewy GA, Chikani V, Sanders AB, Berg RA, Richman PB, Kern KB.
JAMA. 2008 Mar 12;299(10):1158-65.
PMID: 18334691 [PubMed – indexed for MEDLINE]

Free Full Text at JAMA

Passive oxygen insufflation is superior to bag-valve-mask ventilation for witnessed ventricular fibrillation out-of-hospital cardiac arrest.
Bobrow BJ, Ewy GA, Clark L, Chikani V, Berg RA, Sanders AB, Vadeboncoeur TF, Hilwig RW, Kern KB.
Ann Emerg Med. 2009 Nov;54(5):656-662.e1. Epub 2009 Aug 6.
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And more.

 

 

Footnotes:

[1] Ventilation during cardiopulmonary resuscitation-Only mostly dead!
Mosesso VN Jr.
Resuscitation. 2019 Aug;141:200-201. doi: 10.1016/j.resuscitation.2019.06.274. Epub 2019 Jun 22. No abstract available.
PMID: 31238035

 

[2] Association of ventilation with outcomes from out-of-hospital cardiac arrest.
Chang MP, Lu Y, Leroux B, Aramendi Ecenarro E, Owens P, Wang HE, Idris AH.
Resuscitation. 2019 Aug;141:174-181. doi: 10.1016/j.resuscitation.2019.05.006. Epub 2019 May 18.
PMID: 31112744

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