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  • Prof Peter Cameron

JOURNAL CLUB – NOVEMBER 2021

Updated: Nov 3, 2023

Journal Club Podcast for November 2021

Prof Peter Cameron Dr Eleanor Junckerstorff Dr Eanna Mac Suibhne

Editor: Dr David McCreary



🤓  Editor's note: Yes, some audio issues this month - we promise that next month Eanna's dulcet Irish tones will be silky smooth 🎙


Welcome to the Journal Club Podcast for November 2021. You can listen to the podcast above and have a read at our summary below, courtesy of our senior registrar for research, Dr Eanna Mac Suibhne. Another month and another Journal Club. This month we reviewed four more papers, covering a range of topics which have practical considerations for daily practice. The first paper we reviewed was the Headache in the Emergency Department study. This was published in Headache, the journal of head and face pain in October of this year by Pellatt et al. The award for the coolest name goes to the authors of the Tomahawk trial which was the second paper we looked at. This was published in the New England journal of Medicine in August of this year by Stefan Desch et al. The third paper we reviewed was published in the BMJ this September by Gray et al. This was an RCT which questioned the use of early CTCA in patients who fell into the intermediate risk group for ACS. Finally, we reviewed an interesting study which as published in Anaesthesia by Wilson et al. This study examined aerosol generation with varying respiratory activities and NIV. Topical and has real time implications for how departments operate in this current COVID 19 climate.

PAPER 1: THE HEADACHE IN EMERGENCY DEPARTMENTS STUDY: OPIOID PRESCRIBING IN PATIENTS PRESENTING WITH HEADACHE. A MULTI-CENTER, CROSS-SECTIONAL, OBSERVATIONAL STUDY

READ IT HERE


CLINICAL QUESTION:

What is the pattern of use of opiates in the management of headaches in the emergency department internationally?


FINDINGS

4536 patients were enrolled, with the highest responders coming from Australia and New Zealand. Opioid use was noted to be highest in these countries, both in the prehospital setting and in the ED. Opioid prescription on discharge was highest in Singapore and Hong Kong and the greatest predictor of opioid prescription at discharge was administration in the ED. Predictors of Opioid administration were severe headache, pre-ED opioid use and long-term opioid use.


AUTHORS' CONCLUSIONS

Internationally, trends in opioid prescribing vary. The findings support education around policy and guidelines to ensure adherence to evidence-based interventions for headache.


JOURNAL CLUB THOUGHTS

An ambitious study, but one where the poor response rates from the countries involved doesn’t allow for a proper reflection of opiate prescription trends in those countries. Prehospital services in some countries do not facilitate opiate administration to patients which also skews the results. The study does serve as an important reminder about considered opiate prescribing in the ED. With high rates of opiate use in the community, the societal difficulties that results from this and with no evidence base for the use of opiates in headache management it’s a timely reminder for physicians to think twice about what they are prescribing.


PAPER 2: ANGIOGRAPHY AFTER OUT-OF-HOSPITAL CARDIAC ARREST WITHOUT ST-SEGMENT ELEVATION

READ IT HERE


CLINICAL QUESTION:

In adults > 30 years old who suffer an out-of-hospital cardiac arrest (OOHCA) without ST elevation on their ECG, does routine immediate coronary angiography compared to a delayed or selective approach to coronary angiography improve 30-day all-cause mortality?


FINDINGS

All patients over 30 years of age with both shockable and non-shockable rhythms during their arrest were included in this study. The primary outcome was all cause mortality at 30 days. The authors found no significant difference between immediate angiography vs. delayed / selective Angiography (54 vs 46%). There were also no significant differences detected between any of the secondary outcomes. These included MI at 30 days, sever neurological deficit, ICU length of stay and combination of death from any cause at 30 days.


AUTHORS' CONCLUSIONS

In resuscitated patients with a possible cardiac cause of OOHCA without ST elevation or LBBB, an immediate coronary angiography strategy did not reduce 30 day risk of death from any cause compared to a delayed or selective coronary angiography strategy.


JOURNAL CLUB THOUGHTS

So the COACT trial was the pretext to this, where it was found that in those with an initial shockable rhythm without ST elevation on their ECG that immediate coronary angiography did not improve 90-day mortality. This study went one further and possibly more reflective of the patient cohort we see; the undifferentiated cardiac arrest.


This was an open label trial so very difficult to blind a study like this. In terms of strengths, it is a clinically important question and included both shockable and non-shockable rhythms.


Authors looked for a 12% absolute difference between the groups which was ambitious. As an outcome, death is a hard end point, can’t argue with it.


The 30 day follow up period was possibly too short. A longer term follow up may reveal some clinically important differences between the groups e.g LV function.

In going forward should this study forces us to think carefully about what is offered by getting early angio. Considered post resuscitation care is key as not all cardiac arrests are due to ACS. If we push for cath lab immediately, we could be delaying identification of other potential significant causes e.g PE/ aortic dissection. The cath lab is not a destination for resuscitation.


PAPER 3: EARLY COMPUTED TOMOGRAPHY CORONARY ANGIOGRAPHY IN PATIENTS WITH SUSPECTED ACUTE CORONARY SYNDROME: RANDOMISED CONTROLLED TRIAL

READ IT HERE


CLINICAL QUESTION:

Does the use of early CT coronary angiography improve clinical outcomes at one year in patients deemed to be at intermediate risk of Acute Coronary syndrome and presenting to the ED with chest pain.


FINDINGS

The authors identified their primary endpoint to be all cause death or subsequent type 1 or 4b myocardial infarction at one year. Patients were randomised to either Early CT coronary angiography and standard of care or to standard of care only. The primary endpoint occurred in 51 (5.8%) participants randomised to CT coronary angiography and 53 (6.1%) participants who received standard of care only. There were no overall differences in coronary revascularisation, use of drug treatment for acute coronary syndrome, or subsequent preventive treatments between the two groups.


AUTHORS' CONCLUSIONS

In intermediate risk patients with acute chest pain and suspected acute coronary syndrome, early CT coronary angiography did not alter overall coronary therapeutic interventions or one year clinical outcomes. These findings do not support the routine use of early CT coronary angiography in intermediate risk patients with acute chest pain and suspected acute coronary syndrome.


JOURNAL CLUB THOUGHTS

There were a few issues raised at journal club regarding this paper. The standard of care was not defined, the study power and sample size were recalculated midway through the study, and the secondary endpoints were refined during the trial.


This isn’t an emergency medicine specific study but it has relevance to a presentation which is common in ED, and does raise questions regarding resource use and flow in the hospital. This study found that pt’s in the intermediate group had longer length of stay if they received CTCA. That being said, fewer participants in the CT coronary angiography arm received invasive coronary angiography: 474 (54.0%) compared with 530 (60.8%) in the standard of care arm.


It didn’t affect management as standard of care sought to treat the patients with invasive angiography and revascularisation. No space in the risk group selected to affect change. To improve outcomes, it would have to be in undifferentiated/ lower risk cardiac change where it can detect unrecognised cardiac coronary artery disease.


The use of early CT coronary angiography had no effect on rates of treatments for acute coronary syndrome, with similar rates of use of drug treatment for acute coronary syndrome, coronary revascularisation, and preventive treatments at discharge from hospital. These findings are likely to reflect the high sensitivity of current clinical assessment, combining testing for cardiac troponin with a 12 lead ECG.


PAPER 4: THE EFFECT OF RESPIRATORY ACTIVITY, NON‐INVASIVE RESPIRATORY SUPPORT AND FACEMASKS ON AEROSOL GENERATION AND ITS RELEVANCE TO COVID‐19.

READ IT HERE


CLINCIAL QUESTION:

Do clinically indicated respiratory therapies produce similar or greater aerosols compared to exertional respiratory activities in patients with Covid -19.


FINDINGS

The researchers built a new chamber providing extremely clean air, in which 10 healthy volunteers sat. They breathed into a large cone while receiving high flow nasal oxygen and Non-invasive positive pressure ventilation and then while performing respiratory activities simulating the respiratory activities of patients with COVID 19.  Particles that were breathed out were collected and collated.


The respiratory therapies showed slight increases in total particle counts at higher flows and pressures relative to the quiet breathing benchmark. Particle counts reduced when HFNO was used during respiratory activities, and significantly during coughing where emissions were halved. During exercise, the respiratory therapies reduced particle counts by 30-60%.


AUTHORS' CONCLUSIONS

Exertional respiratory activities themselves are the primary modes of aerosol generation and represent a greater transmission risk than is widely recognised currently. Therefore, increased measures targeting physiologically generated aerosols could protect patients, healthcare workers and the public from respiratory pathogens, including SARS-CoV-2.


JOURNAL CLUB THOUGHTS

A novel study asking a topical and important question. Higher prevalence of infection has been observed in healthcare workers caring for Covid 19 patients using droplet compared with aerosol measures.


In terms of weaknesses, these were healthy subjects, so we are not able to reliably state if physiological exertion and respiratory symptoms increase total viral and aerosol emissions in infected patients. Also, the researches did not measure aerosol generation during mask removal.


Classification of  HFNO  and  NIPPV  as  aerosol-generating procedures may have two serious adverse consequences. First, the risk from common respiratory activities may be underestimated, so effective precautions will not be used widely and second, patients may have delayed or restricted access to beneficial therapies.


The study reinforces current practices in place at the Alfred.


REFERENCES

  1. Pellatt RAF, Kamona S, Chu K, Sweeny A, Kuan WS, Kinnear FB, et al. The Headache in Emergency Departments study: Opioid prescribing in patients presenting with headache. A multicenter, cross‐sectional, observational study. Headache J Head Face Pain. 2021;61(9):1387–402.

  2. Desch S, Freund A, Akin I, Behnes M, Preusch MR, Zelniker TA, et al. Angiography after Out-of-Hospital Cardiac Arrest without ST-Segment Elevation. New Engl J Med. 2021;

  3. Gray AJ, Roobottom C, Smith JE, Goodacre S, Oatey K, O’Brien R, et al. Early computed tomography coronary angiography in patients with suspected acute coronary syndrome: randomised controlled trial. Bmj. 2021;374:n2106.

  4. Wilson NM, Marks GB, Eckhardt A, Clarke AM, Young FP, Garden FL, et al. The effect of respiratory activity, non‐invasive respiratory support and facemasks on aerosol generation and its relevance to COVID‐19. Anaesthesia. 2021;76(11):1465–74.

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