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

- Rogue Medic

Is Hydroxychloroquine Effective Against COVID-19?

     
As with any popular treatment, there are plenty of people who want us to ignore the research, or to focus on giving people hope. That is not a reasonable, or ethical, approach to medicine. That is not even a medical approach to medicine. If we lower our standards enough, we can claim that everything works, but that would kill a lot more people than only using treatments based on EBM (Evidence Based Medicine). Should we make excuses for lowering our standards, and killing people, or should we insist on raising our standards?

There is currently a pandemic, so there is a bit of a rush to find something that works, which some people mistake for a need to provide hope. If you want hope, you can pray and there should not be any harmful effects of praying. However knowing that you were being prayed for by others has been associated with a significantly higher incidence of complications. In other words, praying for yourself or others is fine, but telling others that you are going to pray for them is probably harmful, even though your intent is to help.[1]

The reasonable way to look at taking medicine is take only those treatments that have been demonstrated to improve outcomes for people with the studied diagnosis, when you have that diagnosis. Everything else is a crap shoot, where you don’t even know the risks – and there probably is no benefit.

Why do I state that the risks to the person taking the treatment are unlimited, but the benefits probably do not exist?

That is the history of the study of treatments. Almost everything proposed as a treatment has been more harmful than beneficial. It would be nice if this were not true, but reality doesn’t care about being nice. All of alternative medicine falls into the category of probably more harmful than safe and unlikely to be of any benefit, other than a benefit to the finances of the person selling the alt med.

Is hydroxychloroquine alternative medicine? Hydroxychloroquine is approved as real medicine for malaria, lupus erythematosus, and rheumatoid arthritis.[2] For these diagnoses, hydroxychloroquine is not alternative medicine. For everything else, the use is off-label, which is a legal way of saying alternative medicine, as far as the FDA (Food and Drug Administration) is concerned. Sometimes off-label use can be supported by good evidence, but the treatment has not been submitted to the FDA for approval for that diagnosis, but that is not the case with hydroxychloroquine. The FDA issued an EUA (Emergency Use Authorization) for hydroxychloroquine limited to adults and adolescents who weigh 50 kg (approximately 110 pounds) or more, who were hospitalized with COVID-19, and for whom participation in a clinical trial was not available, or participation was not feasible.[3]

Why are those limitations important?

1. If a treatment is effective, diverting patients from clinical trials will delay learning that the treatment is effective, which will significantly decrease the number of lives saved.

2. If a treatment is not effective, diverting patients from clinical trials will delay learning that the treatment is not effective, which will significantly decrease the number of lives saved, because patients are receiving a useless distraction from effective treatment.

3. If a treatment is harmful, which is much worse than just being not effective, diverting patients from clinical trials will delay learning that the treatment is harmful, which will significantly increase the number of patients killed.

All of those results – and those are the possibilities – are ignored by those who reject research. No treatment, however good, will be purely beneficial. All treatments have adverse effects. however, the reverse of that is not true. A treatment that is harmful often does not provide any benefit.

The odds are always against the patient. Any doctor trying to just do something is endangering patients. Kitchen sink medicine (throwing everything at the patient, just in case) has always been bad medicine.

There is a good discussion of the evidence in two podcasts:

15. Covid-19: Is There a Case for Hydroxychloroquine?
Stimulus with Rob Orman, MD (who also hosts the ERCast)
July 30, 2020
Podcast page

Dr. Orman does not specifically mention the Arshad study, which claims to show a benefit in patients treated with HCQ (HydroxyChloroQuine), AZM (AZithroMycin), and HCQ+AZM (HydroxyChloroQuine + AZithroMycin), but that does not change the conclusion of an examination of the evidence.[4]


COVID-19 Treatment Update: Can We Just Stop Wasting Time on Hydroxychloroquine
Written by Salim Rezaie
July 6, 2020
Podcast page

Here is the most important point from Salim Rezaie about the outcomes from the Arshad study:

As most patients in this trial receiving HCQ or HCQ + AZM received steroids and the patients receiving AZM alone or neither therapy had far fewer patients receiving steroids, the likely mortality benefit of this trial is due to the steroids and not the HCQ or HCQ + AZM


Dr. Rezaie concludes: This study should not change clinical practice of not prescribing these medications.

The Arshad study is being used by proponents of hydroxychloroquine alternative medicine to try to contradicting higher quality research, which is the reason it is not real medicine. When there is only low quality evidence, we should be cautious in recommending any treatment. When the high quality evidence shows that the low quality evidence is misleading, we should ignore the low quality evidence until there is high quality evidence to support the findings of the low quality evidence. Don’t expect that to happen.

The reason most medical research is overturned is the reliance on low quality evidence.[5], [6], [7], [8]


Footnotes:

[1] Study of the Therapeutic Effects of Intercessory Prayer (STEP) in cardiac bypass patients: a multicenter randomized trial of uncertainty and certainty of receiving intercessory prayer
Herbert Benson 1, Jeffery A Dusek, Jane B Sherwood, Peter Lam, Charles F Bethea, William Carpenter, Sidney Levitsky, Peter C Hill, Donald W Clem Jr, Manoj K Jain, David Drumel, Stephen L Kopecky, Paul S Mueller, Dean Marek, Sue Rollins, Patricia L Hibberd
Am Heart J. 2006 Apr;151(4):934-42. doi: 10.1016/j.ahj.2005.05.028.
PMID: 16569567

Our study had 2 main findings. First, intercessory prayer itself had no effect on whether complications occurred after CABG. Second, patients who were certain that intercessors would pray for them had a higher rate of complications than patients who were uncertain but did receive intercessory prayer.



[2] Hydroxychloroquine Sulfate tablet
INDICATIONS AND USAGE
Daily Med
FDA Label


[3] Frequently Asked Questions on the Revocation of the Emergency Use Authorization for Hydroxychloroquine Sulfate and Chloroquine Phosphate
FDA
Page as PDF download

Q. Why did FDA grant the EUA for hydroxychloroquine sulfate (HCQ) and chloroquine phosphate (CQ) for the treatment of COVID-19 initially?
A. On March 28, 2020, BARDA requested and FDA issued an Emergency Use Authorization (EUA) for emergency use of oral formulations of chloroquine phosphate (CQ) and hydroxychloroquine sulfate (HCQ) for the treatment of COVID-19. Based on the scientific information available to FDA as of that date, the Agency determined that CQ and HCQ may be effective in treating COVID-19 and that the known and potential benefits of CQ and HCQ outweighed the known and potential risks for this use. The agency limited the use of authorized products to adults and adolescents who weigh 50 kg (approximately 110 pounds) or more, who were hospitalized with COVID-19, and for whom participation in a clinical trial was not available, or participation was not feasible.



[4] Treatment with hydroxychloroquine, azithromycin, and combination in patients hospitalized with COVID-19
Samia Arshad,a Paul Kilgore,b,c Zohra S. Chaudhry,a Gordon Jacobsen,e Dee Dee Wang,d Kylie Huitsing,a Indira Brar,a George J. Alangaden,a,c Mayur S. Ramesh,a John E. McKinnon,a William O’Neill,d Marcus Zervos,a,c,⁎ and Henry Ford COVID-19 Task Force1
Int J Infect Dis. 2020 Aug; 97: 396–403.
Published online 2020 Jul 2. doi: 10.1016/j.ijid.2020.06.099
PMID: 32623082

PMCID: PMC7330574 (Free Full Text from PubMed Central)


[5] Why Most Published Research Findings Are False
John P. A. Ioannidis
PLoS Med. 2005 Aug; 2(8): e124.
Published online 2005 Aug 30. doi: 10.1371/journal.pmed.0020124
PMID: 16060722

PMCID: PMC1182327 (Free Full Text from PubMed Central)

The probability that a research claim is true may depend on study power and bias, the number of other studies on the same question, and, importantly, the ratio of true to no relationships among the relationships probed in each scientific field. In this framework, a research finding is less likely to be true when the studies conducted in a field are smaller; when effect sizes are smaller; when there is a greater number and lesser preselection of tested relationships; where there is greater flexibility in designs, definitions, outcomes, and analytical modes; when there is greater financial and other interest and prejudice; and when more teams are involved in a scientific field in chase of statistical significance.



[6] Evidence-based de-implementation for contradicted, unproven, and aspiring healthcare practices
Vinay Prasad and John PA Ioannidis
Implement Sci. 2014; 9: 1.
Published online 2014 Jan 8. doi: 10.1186/1748-5908-9-1
PMID: 24398253

PMCID: PMC3892018 (Free Full Text from PubMed Central)

Abandoning ineffective medical practices and mitigating the risks of untested practices are important for improving patient health and containing healthcare costs. Historically, this process has relied on the evidence base, societal values, cultural tensions, and political sway, but not necessarily in that order. We propose a conceptual framework to guide and prioritize this process, shifting emphasis toward the principles of evidence-based medicine, acknowledging that evidence may still be misinterpreted or distorted by recalcitrant proponents of entrenched practices and other biases.


[7] Observational studies often make clinical practice recommendations: an empirical evaluation of authors’ attitudes
Vinay Prasad 1, Joel Jorgenson, John P A Ioannidis, Adam Cifu
J Clin Epidemiol.
2013 Apr;66(4):361-366.e4.
PMID: 23384591   DOI: 10.1016/j.jclinepi.2012.11.005

It is common to see new studies contradict previous adopted standards of care [25,26]. Even the results of highly cited studies can be refuted [7], and the replication rate tends to be low for claims made from observational designs [7]. We have previously noted that the most common correlate for reversal of standards of care was the original adoption of a practice based on nonrandomized evidence alone [27]. The studies examined here offer many recommendations that may be precarious or erroneous. If adopted, such practices may need to be reversed in the future after having been detrimental to health, health finances, and the reputation of medical science.



[8] Contradicted and initially stronger effects in highly cited clinical research
John P A Ioannidis
JAMA. 2005 Jul 13;294(2):218-28. doi: 10.1001/jama.294.2.218.
PMID: 16014596   DOI: 10.1001/jama.294.2.218

Free Full Text from JAMA

Of the 45 eligible highly cited studies with efficacy claims (Table 2), 7 (16%) were contradicted by subsequent research, and another 7 (16%) were found to have initially stronger effects. In all these 14 cases (BOX 1), subsequent studies were either larger or better controlled (randomized vs a nonrandomized original study). The findings of 20 highly cited articles (44%) were replicated (also with a larger sample size in subsequent research compared with the original highly cited study) and 11 (24%) had remained largely unchallenged.58-78



.

Hydroxychloroquine – The More You Know, The Worse It Looks



Do you want to use a drug that was never based on any good evidence, but only a hunch? Try hydroxychloroquine. The president says, What have you got to lose?


Kitchen sink medicine is a remnant of the Dark Ages, but it has not been eliminated from medicine. It is the argument from ignorance. If you can’t prove that the treatment is harmful, the treatment is wonderful. If you can prove the treatment is harmful, you are part of a conspiracy.


This is further evidence that hydroxychloroquine is harmful. The higher the quality of the evidence about hydroxychloroquine, the worse hydroxychloroquine looks.


Today, Lancet published this study comparing almost 15,000 patients receiving several different experimental treatments with about 80,000 patients not receiving any of the experimental treatments. This should convince reasonable people that there is no justification for treating patients with hydroxychloroquine outside of a well controlled randomized trial.


The comments on articles about the study are full of the usual anti-science, anti-vax, alternative medicine propaganda. Their religion has failed, but they keep preaching.


After controlling for multiple confounding factors (age, sex, race or ethnicity, body-mass index, underlying cardiovascular disease and its risk factors, diabetes, underlying lung disease, smoking, immunosuppressed condition, and baseline disease severity), when compared with mortality in the control group (9·3%), hydroxychloroquine (18·0%; hazard ratio 1·335, 95% CI 1·223–1·457), hydroxychloroquine with a macrolide (23·8%; 1·447, 1·368–1·531), chloroquine (16·4%; 1·365, 1·218–1·531), and chloroquine with a macrolide (22·2%; 1·368, 1·273–1·469) were each independently associated with an increased risk of in-hospital mortality.[1]


The evidence shows that you are twice as likely to die if you receive hydroxychloroquine.


Don’t listen to anti-science, anti-vax, anti-medicine preachers, because they are not interested in your health.


What have you got to lose?


What are you treating, you politics/religion or your health?


If your goal is to treat your religion, go ahead and use the magic elixir and maybe you will not be harmed by it.


If your goal is to treat your health, avoid magic claims about treatments, regardless of the treatment. Use treatments that work in the real world.


What have you got to lose?


You are twice as likely to lose your life. Among survivors, the significant adverse effect rate was much higher in the hydroxychloroquine groups. This is the highest quality research so far and there is no good news for the hydroxychloroquine.


Read the full paper and think for yourself. Don’t listen to those making excuses to promote their agenda. Your health has never been important to those who reject science.


It is unfortunate that we do not have some treatment that works well, but that is not a good reason to bet your life on bad medicine. More people survive with better health with conventional treatment.



Footnotes:


[1] Hydroxychloroquine or chloroquine with or without a macrolide for treatment of COVID-19: a multinational registry analysis
Prof Mandeep R Mehra, MD, Sapan S Desai, MD, Prof Frank Ruschitzka, MD, Amit N Patel, MD
Lancet. Published:May 22, 2020
DOI:https://doi.org/10.1016/S0140-6736(20)31180-6


Free Full Text from Lancet.


.

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.[3] 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”.[4] 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.

[4] “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

.

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.
PMID: 19660833 [PubMed – indexed for MEDLINE]

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

.

How Effective Is Epinephrine for Improving Survival Among Patients in Cardiac Arrest?

   

There have been two studies comparing epinephrine with placebo to treat out of hospital cardiac arrest. The Jacobs study was stopped early, because of interference by those who do not want to know if their medicine actually works.[1] The purpose of research is to determine, as objectively as possible, if a treatment is better than placebo nothing.  

Click on the image to make it larger.  

Even the small sample size shows a impressive p values of <0.001 for both ROSC (Return Of Spontaneous Circulation) and being admitted to the hospital. Unfortunately, that does not lead to outcomes that are better than placebo.

The Perkins study (PARAMEDIC2) did not find a significant difference between adrenaline (epinephrine in non-Commonwealth countries) and placebo.[2] The Jacobs study also did not find a difference, but the numbers were small, due to the interference by the less than knowledgeable. Following the Jacobs study, some intervention proponents have suggested that the problem is not a lack of evidence of benefit, but need to look at the evidence from the right perspective. The inadequate evidence is not “inadequate”, but really just misunderstood. All we need to do is use a method of analysis that compensates for the tiny sample size. A Bayesian approach will produce the positive outcome that is not justified by so few patients.[3]

What happens when the numbers are combined, so that the sample size is large enough to eliminate the need for statistical chicanery to come up with something positive?

The outcomes do not improve.  

Neither standard dose adrenaline, high-dose adrenaline,vasopressin nor a combination of adrenaline and vasopressin improved survival with a favourable neurological outcome.[4]
 

If the Bayesian approach were appropriate, then the much larger sample size would have provided more than enough patients to confirm the optimism of the epinephrine advocates. The result is still not statistically significant. Maybe a much, much larger study will show a statistically significant, but tiny, improvement in outcomes with epinephrine, but don’t hold your breath for that. It took half a century to produce the first study, then seven more years for the second. With the cost of research and the problems coordinating such a large study, it is more likely that the guidelines will continue to recommend spending a lot of time and money giving a drug that diverts attention from the interventions that do improve outcomes.

There is still no evidence that adrenaline provides better outcomes than placebo in human cardiac arrest patients.

  –  

Footnotes:

  –  

[1] Effect of adrenaline on survival in out-of-hospital cardiac arrest: A randomised double-blind placebo-controlled trial Jacobs IG, Finn JC, Jelinek GA, Oxer HF, Thompson PL. Resuscitation. 2011 Sep;82(9):1138-43. doi: 10.1016/j.resuscitation.2011.06.029. Epub 2011 Jul 2. PMID: 21745533

Free Full Text PDF Download from semanticscholar.org  

This study was designed as a multicentre trial involving five ambulance services in Australia and New Zealand and was accordingly powered to detect clinically important treatment effects. Despite having obtained approvals for the study from Institutional Ethics Committees, Crown Law and Guardianship Boards, the concerns of being involved in a trial in which the unproven “standard of care” was being withheld prevented four of the five ambulance services from participating.

In addition adverse press reports questioning the ethics of conducting this trial, which subsequently led to the involvement of politicians, further heightened these concerns. Despite the clearly demonstrated existence of clinical equipoise for adrenaline in cardiac arrest it remained impossible to change the decision not to participate.

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[2] A Randomized Trial of Epinephrine in Out-of-Hospital Cardiac Arrest. Perkins GD, Ji C, Deakin CD, Quinn T, Nolan JP, Scomparin C, Regan S, Long J, Slowther A, Pocock H, Black JJM, Moore F, Fothergill RT, Rees N, O’Shea L, Docherty M, Gunson I, Han K, Charlton K, Finn J, Petrou S, Stallard N, Gates S, Lall R; PARAMEDIC2 Collaborators. N Engl J Med. 2018 Aug 23;379(8):711-721. doi: 10.1056/NEJMoa1806842. Epub 2018 Jul 18. PMID: 30021076

Free Full Text from N Engl J Med.

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[3] Regarding “Effect of adrenaline on survival in out-of-hospital cardiac arrest: A randomised double-blind placebo-controlled trial”. Youngquist ST, Niemann JT. Resuscitation. 2012 Apr;83(4):e105; author reply e107. doi: 10.1016/j.resuscitation.2011.09.035. Epub 2012 Jan 18. No abstract available. PMID: 22266068

Free Full Text from Resuscitation.

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[4] Adrenaline and vasopressin for cardiac arrest. Finn J, Jacobs I, Williams TA, Gates S, Perkins GD. Cochrane Database Syst Rev. 2019 Jan 17;1:CD003179. doi: 10.1002/14651858.CD003179.pub2. PMID: 30653257    

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ACLS Excuses for Causing Harm with Epinephrine

 

The next ACLS guidelines are available for review and comment, before they are finalized. The Consensus on Science with Treatment Recommendations (CoSTR) from the International Liaison Committee on Resuscitation (ILCOR) are available for two guidelines:

Vasopressors in Adult Cardiac Arrest

Advanced Airway Management During Adult Cardiac Arrest

We have been using these interventions for so long, that there should be great evidence to show that benefits and harms of both interventions, but there is no good evidence to support either intervention.

For epinephrine (adrenaline in Commonwealth countries), the most commonly used vasopressor and the only one rally being considered, there is no evidence of actual benefit – increased survival without severe brain damage.

Nothing else matters.

There is no valid evidence that increasing any surrogate endpoint improves survival without severe brain damage. The evidence cited by ILCOR shows that epinephrine increases the rate of severe brain damage.
 

Intervention: Vasopressor or a combination of vasopressors provided intravenously or intraosseously during cardiopulmonary resuscitation.[1]

 

Here are the outcomes that are supposed to indicate that the patient is better.
 

Outcomes: Short-term survival (return of spontaneous circulation (ROSC) and survival to hospital admission), mid-term survival (survival to hospital discharge, 28 days, 30 days, or 1 month), mid-term favorable neurological outcomes (Cerebral Performance Category score of 1-2 or modified Rankin Scale 0-3 at hospital discharge, 28 days, 30 days, or 1 month) and long-term favorable and poor (modified Rankin Score 4-5) neurological outcomes (after 1 month).[1]

 

Is ROSC an improvement?

We aren’t supposed to ask that question. These are faulty assumption that the guidelines are based on.

1. Doing something more is better than only doing things supported by valid evidence of improved survival without severe brain damage.

No.

How much harm is being caused in this rush to get a pulse back?

We are supposed to ignore our understanding of research, look at a statistically insignificant “trend”, and extrapolate that statistically insignificant “trend” to support the prejudice that our intervention has not been harmful.

That is not good science.

That is not good medicine.
 

Why aren’t there any studies large enough to show improved survival without severe brain damage for anything other than rapid defibrillation (when indicated VF/pulseless VT) and chest compressions?

The research has only produced excuses and surrogate endpoint. Surrogate endpoints are for hypothesis generation and sales pitches to the least knowledgeable, but not for treatment guidelines.

ILCOR has told us this before, but that was because the choice was between large doses of epinephrine and small doses of epinephrine, not between epinephrine and no epinephrine.

The choice is the same.

Is the more aggressive intervention helping?

The answer is the same. No. That is not the conclusion of the evidence.
 

CONCLUSIONS
In adults with out-of-hospital cardiac arrest, the use of epinephrine resulted in a significantly higher rate of 30-day survival than the use of placebo, but there was no significant between-group difference in the rate of a favorable neurologic outcome because more survivors had severe neurologic impairment in the epinephrine group.[2]

 

If the goal is a pulse with more severe brain damage, then epinephrine is the way to go.

If the goal is increased survival without severe brain damage, we have to keep looking.

We should limit the use of epinephrine to well controlled research until there is evidence of improvement in outcomes that matter.

If this evidence is never found, our patients will not have been harmed by epinephrine.

If this evidence is eventually found, it is something that should have been insisted on decades ago. We should not use wishful thinking and surrogate endpoints to justify interventions that harm patients.

We used to stop compressions to let the medic/nurse/doctor intubate, or start an IV (IntraVenous) line.

We knew that the tube was more important.

We knew that the drugs given through the IV line were more important.

The 2005 guidelines told us to continue compressions during intubation and during IV attempts and to improve the quality of the compressions.

That focus on high quality compressions is the only time we have improved outcomes that matter.
 

CONCLUSIONS: Compared with controls, patients with out-of-hospital cardiac arrest treated with a renewed emphasis on improved circulation during CPR had significantly higher neurologically intact hospital discharge rates.[3]

 

33 1/3% vs 60% increased survival without severe brain damage.
 

In 2004, we began a statewide program to advocate chest compression-only CPR for bystanders of witnessed primary OHCA. Over the next five years, we found that survival of patients with a shockable rhythm was 17.7% in those treated with standard bystander CPR (mouth-to-mouth ventilations plus chest compression) compared to 33.7% for those who received bystander chest-compression-only CPR.[4]

 

18% vs 34% increased survival only – not increased survival without severe brain damage.
 

In the analysis of MICR [Minimally Interrupted Cardiac Resuscitation] protocol compliance involving 2460 patients with cardiac arrest, survival was significantly better among patients who received MICR than those who did not (9.1% [60/661] vs 3.8% [69/1799]; OR, 2.7; 95% CI, 1.9-4.1), as well as patients with witnessed ventricular fibrillation (28.4% [40/141] vs 11.9% [46/387]; OR, 3.4; 95% CI, 2.0-5.8).[5]

 

9% vs 4% increased survival only – not increased survival without severe brain damage.
 

Neurologic outcomes were also better in the patients who received CCR (OR=6.64, 95% CI=1.31 to 32.8).[6]

 

6 2/3 more likely to have increased survival without severe brain damage. The range is 1 1/3 to almost 33 times, because of the small numbers, but unlike epinephrine, this is statistically significant and supported by other research.

We are still making excuses for using a drug that causes harm and does not appear to provide a benefit that is greater than the harm. If there is more benefit, it is too small to be measured, even in a study with over 9,000 patients. We do not know which patients benefit and which patients are harmed, so we do not know how to minimize the harm that we cause.

Our patients deserve better.

Footnotes:

[1] Vasopressors in Adult Cardiac Arrest
Time left for commenting: 11 days 15:49:49
ILCOR staff
Created: March 21, 2019 · Updated: March 21, 2019
Draft for public comment
Consensus on Science with Treatment Recommendations (CoSTR)
Vasopressors in Adult Cardiac Arrest page for comments until April 04, 2019 at 06:00 Eastern Time

[2] A Randomized Trial of Epinephrine in Out-of-Hospital Cardiac Arrest.
Perkins GD, Ji C, Deakin CD, Quinn T, Nolan JP, Scomparin C, Regan S, Long J, Slowther A, Pocock H, Black JJM, Moore F, Fothergill RT, Rees N, O’Shea L, Docherty M, Gunson I, Han K, Charlton K, Finn J, Petrou S, Stallard N, Gates S, Lall R; PARAMEDIC2 Collaborators.
N Engl J Med. 2018 Aug 23;379(8):711-721. doi: 10.1056/NEJMoa1806842. Epub 2018 Jul 18.
PMID: 30021076

Free Full Text from N Engl J Med.

[3] Implementing the 2005 American Heart Association Guidelines improves outcomes after out-of-hospital cardiac arrest.
Aufderheide TP, Yannopoulos D, Lick CJ, Myers B, Romig LA, Stothert JC, Barnard J, Vartanian L, Pilgrim AJ, Benditt DG.
Heart Rhythm. 2010 Oct;7(10):1357-62. doi: 10.1016/j.hrthm.2010.04.022. Epub 2010 Apr 24.
PMID: 20420938

Free Full Text from Heart Rhythm.

[4] The cardiocerebral resuscitation protocol for treatment of out-of-hospital primary cardiac arrest.
Ewy GA.
Scand J Trauma Resusc Emerg Med. 2012 Sep 15;20:65. doi: 10.1186/1757-7241-20-65. Review.
PMID: 22980487

Free Full Text from PubMed Central.

[5] 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. doi: 10.1001/jama.299.10.1158.
PMID: 18334691

Free Full Text from JAMA.

[6] Cardiocerebral resuscitation is associated with improved survival and neurologic outcome from out-of-hospital cardiac arrest in elders.
Mosier J, Itty A, Sanders A, Mohler J, Wendel C, Poulsen J, Shellenberger J, Clark L, Bobrow B.
Acad Emerg Med. 2010 Mar;17(3):269-75. doi: 10.1111/j.1553-2712.2010.00689.x.
PMID: 20370759

Free Full Text from Acad Emerg Med.

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What Treatments May Be De-Emphasized by EM/EMS in 2019? Part I

 

EM (Emergency Medicine) and EMS (Emergency Medical Services) have already started to eliminate/decrease use of a lot of our failed treatments, because people started to see through our excuses. Atropine for asystole stuck around for a long time, then just vanished.[1]. Calcium for cardiac arrest is also something that used to be standard of care, then we raised our standards.

We need to keep raising our standards, because our patients’ outcomes – their lives, their brains, their everything – depend on raising our standards.

We used to give antiarrhythmics to almost anyone with a cardiac complaint. Then there was CAST (The Cardiac Arrhythmia Suppression Trial[2]). While CAST did not study lidocaine, it did study longer term use of antiarrhythmics. Lidocaine is too dangerous for long term use, so the results of CAST may be much worse for lidocaine. We thought that the increased deaths among patients with frequent PVCs (Premature Ventricular Contractions) after having a heart attack was due to a problem with the conduction system. PVCs indicate a problem with conduction and antiarrhythmics cause the PVCs to go away.
 

Before receiving the antiarrhythmic (PVCs are circled in red).


 

After receiving the antiarrhythmic.


 

Problem solved.

Now the problem is, How do we get paid more? These drugs were the biggest selling drugs at the time. They making the drug companies a fortune. Whichever company made the drug that saved the most lives would make a lot more money then the others. Provide evidence that ______ saves more lives than all of the others.

The problem of the PVCs was solved, but the solution was killing many more patients than not giving drugs.

The result was not celebrated by the drug companies. The patients taking antiarrhythmics were dying at three times the rate of the patients taking placebos. A plausible physiological mechanism suggested the drugs would save lives, but that was based on an assumption that was not justified. This is the kind of reasoning that appeals to those who reject EBM (Evidence-Based Medicine). The evidence should convince these EBM opponents of the folly of relying on physiology and on a plausible explanation to justify not looking for the evidence that might expose their unreasonable assumptions. These otherwise reasonable people start making excuses for unreasonable assumptions, because they believe. They seem to need to convince others to join in and multiply their mistakes.[3]

The PVCs appear to have been just an indicator of an unhealthy heart.

Getting rid of the PVCs may have made the conduction in the heart less healthy.

Giving the drugs may have killed tens of thousands of patients.

Antiarrhythmic use decreased dramatically after the harm demonstrated in CAST, but some drug pushers are trying to get one of the worst antiarrhythmics (amiodarone, now in a new formula) to make a comeback, by creatively spinning research to claim results the research was never designed to evaluate.

Not having learned from the evidence, even though he has been the lead author on some of it, Dr. Peter Kudenchuk has been claiming that in EMS witnessed arrests, there was a significant improvement, even though his own published results contradict this claim. Here is what the results actually state:
 

Though prespecified, this subgroup analysis was performed in the context of an insignificant difference for the overall analysis, and the P value for heterogeneity in this subgroup analysis was not adjusted for the number of subgroup comparisons. Nonetheless, the suggestion that survival was improved by drug treatment in patients with witnessed out-of-hospital cardiac arrest, without evidence of harm in those with unwitnessed arrest, merits thoughtful consideration.[4]

 

Amiodarone has also been shown to be horrible for patients with ventricular tachycardia with a pulse. Amiodarone is so ineffective, that the rate of severe side effects is greater than the rate of improved outcomes. Amiodarone is more likely to make your patient’s medical condition much worse, but it is still considered to be the standard of care and amiodarone is still in EMS protocols.[5]

Maybe amiodarone can produce better results if it is used for execution by lethal injection.

I am expecting that there will be more failed treatments removed from our standards of care.

We need to raise our standards to improve outcomes, not lower our standards to make us look better than we are.

Continued in Part II. I will add Part III and others at some point and provide the links here.

Footnotes:

[1] Why Did We Remove Atropine From ACLS?
Rogue Medic

Part I
Sun, 13 Oct 2013

Part II
Wed, 16 Oct 2013

[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 [PubMed – indexed for MEDLINE]

Free Full Text from NEJM.
 

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. Nonlethal events, however, were equally distributed between the active-drug and placebo groups. The mechanisms underlying the excess mortality during treatment with encainide or flecainide remain unknown.

[3] Why US EMS will never get to sit at the adult table – The Appeal to Authority
Sun, 04 May 2014
Rogue Medic
Article

Since Mike cites the original parachute study, as if it is not satire, it is amusing to point out that there is a new Parachute Study! Read Dr. Radecki’s description of this satirical poke at those who do not understand research in the satire issue of the BMJ, which they put out every Christmas as sort of a British IgNobel.

Don’t Bother With the Parachute!
Emergency Medicine Literature of Note
Dr. Ryan Radecki
December 21, 2018
Article
 

Parachute use to prevent death and major trauma when jumping from aircraft: randomized controlled trial.
Yeh RW, Valsdottir LR, Yeh MW, Shen C, Kramer DB, Strom JB, Secemsky EA, Healy JL, Domeier RM, Kazi DS, Nallamothu BK; PARACHUTE Investigators.
BMJ. 2018 Dec 13;363:k5094. doi: 10.1136/bmj.k5094. Erratum in: BMJ. 2018 Dec 18;363:k5343.
PMID: 30545967

Free Full Text from BMJ.

[4] Amiodarone, Lidocaine, or Placebo in Out-of-Hospital Cardiac Arrest.
Kudenchuk PJ, Brown SP, Daya M, Rea T, Nichol G, Morrison LJ, Leroux B, Vaillancourt C, Wittwer L, Callaway CW, Christenson J, Egan D, Ornato JP, Weisfeldt ML, Stiell IG, Idris AH, Aufderheide TP, Dunford JV, Colella MR, Vilke GM, Brienza AM, Desvigne-Nickens P, Gray PC, Gray R, Seals N, Straight R, Dorian P; Resuscitation Outcomes Consortium Investigators.
N Engl J Med. 2016 May 5;374(18):1711-22. doi: 10.1056/NEJMoa1514204. Epub 2016 Apr 4.
PMID: 27043165

Free Full Text from NEJM.

CONCLUSIONS Overall, neither amiodarone nor lidocaine resulted in a significantly higher rate of survival or favorable neurologic outcome than the rate with placebo among patients with out-of-hospital cardiac arrest due to initial shock-refractory ventricular fibrillation or pulseless ventricular tachycardia.

 

Dr. Kudenchuk is Misrepresenting ALPS as ‘Significant’
Tue, 12 Apr 2016
Rogue Medic
Article
 

Amiodarone, Lidocaine, or Placebo in Out-of-Hospital Cardiac Arrest
Mon, 04 Apr 2016
Rogue Medic
Article

[5] The PROCAMIO Trial – IV Procainamide vs IV Amiodarone for the Acute Treatment of Stable Wide Complex Tachycardia
Rogue Medic
Wed, 17 Aug 2016
Article
 

Randomized comparison of intravenous procainamide vs. intravenous amiodarone for the acute treatment of tolerated wide QRS tachycardia: the PROCAMIO study.
Ortiz M, Martín A, Arribas F, Coll-Vinent B, Del Arco C, Peinado R, Almendral J; PROCAMIO Study Investigators.
Eur Heart J. 2016 Jun 28. pii: ehw230. [Epub ahead of print]
PMID: 27354046

Free Full Text from European Heart Journal.
 

Amiodarone or procainamide for the termination of sustained stable ventricular tachycardia: an historical multicenter comparison.
Marill KA, deSouza IS, Nishijima DK, Senecal EL, Setnik GS, Stair TO, Ruskin JN, Ellinor PT.
Acad Emerg Med. 2010 Mar;17(3):297-306.
PMID: 20370763 [PubMed – indexed for MEDLINE]

Free Full Text from Academic Emergency Medicine.
 

Amiodarone is poorly effective for the acute termination of ventricular tachycardia.
Marill KA, deSouza IS, Nishijima DK, Stair TO, Setnik GS, Ruskin JN.
Ann Emerg Med. 2006 Mar;47(3):217-24. Epub 2005 Nov 21.
PMID: 16492484 [PubMed – indexed for MEDLINE]
 

Intravenous amiodarone for the pharmacological termination of haemodynamically-tolerated sustained ventricular tachycardia: is bolus dose amiodarone an appropriate first-line treatment?
Tomlinson DR, Cherian P, Betts TR, Bashir Y.
Emerg Med J. 2008 Jan;25(1):15-8.
PMID: 18156531 [PubMed – indexed for MEDLINE]
 

Effects of intravenous amiodarone on ventricular refractoriness, intraventricular conduction, and ventricular tachycardia induction.
Kułakowski P, Karczmarewicz S, Karpiński G, Soszyńska M, Ceremuzyński L.
Europace. 2000 Jul;2(3):207-15.
PMID: 11227590 [PubMed – indexed for MEDLINE]

Free Full Text PDF + HTML from Europace
 

Adenosine for wide-complex tachycardia – diagnostic?
Thu, 23 Aug 2012
Rogue Medic
Article
 

Low doses of intravenous epinephrine for refractory sustained monomorphic ventricular tachycardia.
Bonny A, De Sisti A, Márquez MF, Megbemado R, Hidden-Lucet F, Fontaine G.
World J Cardiol. 2012 Oct 26;4(10):296-301. doi: 10.4330/wjc.v4.i10.296.
PMID: 23110246 [PubMed]

Free Full Text from PubMed Central.

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