Journal Club Podcast June 2022
Dr Bertha Wu Dr Rob Mitchell Prof Peter Cameron
WELCOME TO THE JUNE JOURNAL CLUB PODCAST. WE ARE JOINED BY PROFESSOR PETER CAMERON, ACADEMIC DIRECTOR FOR THE ALFRED EMERGENCY AND TRAUMA CENTRE, AND EMERGENCY PHYSICIAN DR ROB MITCHELL.
We will discuss 3 papers this month, covering: delays to inpatient admission from ED and risk of death, use of anti-dopaminergic antiemetics and stroke risk, and the use of CT scans to rule out subarachnoid haemorrhages.
PAPER 1: ASSOCIATION BETWEEN DELAYS TO PATIENT ADMISSION FROM THE EMERGENCY DEPARTMENT AND ALL-CAUSE 30-DAY MORTALITY.
READ IT HERE
CLINICAL QUESTION:
Do delays to inpatient admission from EDs increase the risk of death?
DESIGN
Cross sectional, retrospective observational study
POPULATION (TARGET)
All patients admitted from every major ED in England between April 2016 and March 2018
Only a patient’s first admission in the study period was included.
Patients who waited in the ED for longer than 12 hours were excluded
INTERVENTION / COMPARISON
No intervention/comparator as observational study
Looked at exposure
The time admitted patients spent in ED, up to 12 hours after arrival
Times were measured from the patients’ arrival at the ED until their transfer to an inpatient bed
OUTCOME
Death from all causes within 30 days of admission
FINDINGS
Between April 2016 and March 2018, 26 738 514 people attended an ED, with 7 472 480 patients admitted. 5 249 891 individual patients data was included in the study
Total of 433 962 deaths occurred within 30 days
Overall crude mortality rate was 8.71% (95% CI 8.69% – 8.74%)
Patients on average spent 5 hours in ED
Of the admitted patients, 38% breached the 4-hour rule, which the paper used as a proxy for ED crowding. This is the variable with the largest OR for 30-d mortality of 1.35 (1.33-1.37, p<0.001)
Lower socioeconomic status (measured on a patient deprivation decile of 1-10, with 1=least and 10=most deprived) was also associated with higher 30-d mortality with OR 1.20 for a deprivation decile of 7 and 1.32 for a decile of 10.
Increased standardised mortality rate for patients admitted to hospital after 5 hours
There is a dose-dependent association between time in excess of 5 hours in the ED for admitted patients and all-cause mortality
The standardised mortality rate (SMR) increases in an approximately linear fashion from this point until 12 hours after which accurate data is unavailable
There is a 10% increase in the SMR within 30 days for admitted patients remaining in ED between 8-12 hours in comparison with those who leave the ED within 6 hours.
AUTHORS' CONCLUSIONS
Delays to hospital inpatient admission for patients in excess of 5 hours from time of arrival at the ED are associated with an increase in all-cause 30-day mortality.
JOURNAL CLUB THOUGHTS
This paper’s findings are consistent with those from previous literature. From a methodological point of view, being a retrospective observational study, many confounders could have contributed to the paper’s findings. It was good that the authors addressed the possible mechanisms that may have accounted for patients’ prolonged stay in ED. However, there are nuances and complexities that were not mentioned by the paper. For example, disadvantaged patients like the elderly and confused or the complex medical patients are the ones who are usually get left behind, lingering for hours in ED waiting for an inpatient bed.
BOTTOM LINE
At the end of the day, access block is not an Emergency Department problem. It is a systemic problem that requires addressing with good leadership and a change of culture hospital-wide.
PAPER 2: RISK OF FIRST ISCHAEMIC STROKE AND USE OF ANTIDOPAMINERGIC ANTIEMETICS: NATIONWIDE CASE-TIME-CONTROL STUDY.
READ IT HERE
CLINICAL QUESTION:
Does the use of antidopaminergic antiemetics increase the risk of first stroke?
DESIGN
Case-time control study
POPULATION (TARGET)
>/= 18 years
Diagnosis of first ischaemic stroke between 2012 and 2016
No history of cerebrovascular disease
Had at least one reimbursement for the antidopaminergic antiemetics (ADA) studied – domperidone, metopimazine and metoclopramide – in the 70 days before stroke
Were affiliated with the major health insurance scheme at least during the year of outcome occurrence. Eligible participants were all patients registered on the French health insurance database which contains information on at least 99% of the French population, and where reimbursements to outpatients for dispensed drugs can be found Included:
Excluded:
History of cancer
Hospital admission in the observation period
Had at least once reimbursement for the fixed association metoclopramide aspirin in the observation period on in the year before
INTERVENTION / COMPARISON
The two arms of the study are the case group (participants had first ischaemic stroke during study period), and the exposure time trend control group (participants who didn’t have an ischaemic stroke)
Controls were recruited at the same time as the patients with stroke to take into the account of time trend of ADA use eg natural increase or decrease use of ADA over time
This study looked at the two groups ‘ exposure to the studied ADAs over 4 periods: days -14 to -1 before stroke (the risk period), and days -70 to -57, -56 to -43, and -42 to -29 before stroke (reference periods)
OUTCOME
Association between ADA use and risk of ischaemic stroke
Assessed by estimating the ratio of the odds ratios of exposure evaluated in patients with stroke and in controls
WHAT WERE THE FINDINGS
Amongst 2612 patients with incident stroke, 1250 received an ADA in the risk period, and 1060 in the reference periods
The comparison with 5128 and 13165 respective controls who received an ADA in the same periods yielded a ration of adjusted odds ratio of 3.12 (95% CI 2.85-3.42)
Analysis stratified by age, sex and history of dementia showed similar results
Ratio of adjusted OR for analyses stratified by ADA was 2.51 (2.18-2.88) for domperidone, 3.62 (3.11-4.23) for metopimazine, and 3.53 for metoclopramide
Sensitivity analysis suggested that the risk would be higher in the first days of use
AUTHORS' CONCLUSIONS
There is an increased risk of ischaemic stroke with recent ADA use. The highest increase was found for metopimazine and metoclopramide.
JOURNAL CLUB THOUGHTS
It was a great effort by the authors as there were a large number of participants. It was interesting that patients who had intravenous ADAs weren’t included, as one would imaging drugs given via the IV route would have the most intended or unintended effect. Further, the study did not detail why the patients required the ADA to being with.
Was it because the patient developed vertigo as a prodrome of a posterior circulation stroke? Or that the patient had a significant illness that precipitated the stroke? The authors called this “protopathic bias” and did attempt to correct for this with a sensitivity analysis. However, this remains a design flaw that we’re not convinced can be adjusted for with statistical maneuvers.
BOTTOM LINE
The study findings are not convincing at a biological and clinical level, and won’t change our current practice.
PAPER 3: SENSITIVITY OF MODERN MULTISLICE CT FOR SUBARACHNOID HAEMORRHAGE AT INCREMENTAL TIMEPOINTS AFTER HEADACHE ONSET: A 10-YEAR ANALYSIS.
READ IT HERE
CLINICAL QUESTION:
Is it possible to extend the timeframe from headache onset within which modern multislice CT can be used to rule out aneurysmal subarachnoid haemorrhage (SAH)?
DESIGN
Single centre, retrospective cohort study
POPULATION (TARGET)
Patients who had diagnosis of subarachnoid haemorrhage presenting to Christchurch Hospital between 2007 and 2017Excluded:
Traumatic SAH
Repeat SAH admission during the study time period
SAH found on postmortem in whom no MSCT was performed
The day of onset of headache was not recorded
Patient transferred to Christchurch Hospital from another hospital
Patients with lost or destroyed records
Cases miscoded as SAH
INTERVENTION / COMPARISON
Exposure: Imaging with multislice CT (MSCT) head
OUTCOMES
Primary: Proportion of patients with spontaneous aneurysmal SAH that had a positive MSCT
Secondary: The proportion of patients with any type of spontaneous SAH that had a positive MSCT
FINDINGS
Out of 347patients with a SAH, 260 had an aneurysmal SAH
MSCT identified 253 (97.3%) of all aneurysmal SAH and 332 (95.7%) of all SAH
Of the 15 (2.7%) of patients not identified with MSCT, 7 (47%) were aneurysmal SAH diagnosed with SAH using a combination of LP and/or MRI
Coroners mortality database was examined – no sudden deaths with SAH where patients had a recent related ED presentation where a head MSCT was performed
There were 224 patients where the time of headache onset was not recorded
Of these , onset was the same day as arrival in the ED in 148 (66%) of patients
For these patients, the time of headache onset was imputed as 30min prior to arrival time for analysis to maximise the number of early false negatives
For patients with headache onset during the preceding day, a time of 23:59 was imputed for analysis
At 24 hours after headache onset, the sensitivity of MSCT for aneurysmal SAH was 100% (95% CI 98.3-100)
At 48 hours after headache onset, the sensitivity of MSCT was 99.6% (95% CI 97.6-100) for aneurysmal SAH and 99% (95% CI 97.1-99.8) for all SAH
The sensitivity of MSCT for all SAH decreased as time to MSCT increased
AUTHORS' CONCLUSIONS
It may be possible to extend the timeframe from headache onset within which modern MSCT can be used to rule out aneurysmal SAH
JOURNAL CLUB THOUGHTS
This study supports what many Emergency Physicians are doing currently. We know that with improvement of technology over the years, the sensitivity of CT brains and their ability to detect a subarachnoid haemorrhage beyond the 6 hours mark has also improved. Our experienced guest speakers recommended using clinical judgement when you decide what to do next after a negative CTB performed after 6 hours. There is little added benefit of performing a lumbar puncture. If there is a high pre-test probability of the patient having a subarachnoid haemorrhage, then a CT angiogram should be considered.
BOTTOM LINE
When a CTB is done beyond 6 hours of headache onset, whether any subsequent tests is required to rule out a SAH as the cause of the headache should be based on clinical judgement of pretest probability, taking into account that modern CT scanners have much better sensitivity to detect SAH.
REFRENCES
Jones S, Moulton C, Swift S, et al. Association between delays to patient admission from the emergency department and all-cause 30-day mortality. Emerg Med J 2022 Mar;39(3):168-173.
Benard-Laribiere A, Hucteau E, Debette S, et al. Risk of first ischaemic stroke and use of antidopaminergic antiemetics: nationwide case-time-control study. BMJ 2022;376:e066192.
Vincent A, Pearson S, Pickering JW, et al. Sensitivity of modern multislice CT for subarachnoid haemorrhage at incremental timepoints after headache onset: a 10-year analysis. Emergency Medicine Journal. Published Online First: 24 November 2021.
DR BERTHA WU
Emergency Registrar
MBBS, CCPU (eFAST, AAA, BELS). Emergency Medicine Advanced Trainee and Intensive Care Medicine Trainee in Melbourne, Australia. Particular interests in POCUS, medical education and health care in resource-poor settings. Twitter: @berthawu29
