I am delighted to see agreement between Taylor's article and the Dept
of Health guidance on recording of arrival times. Taylor et al recommend
that "the time the ambulance pulls up outside the department should no
longer represent a patient’s arrival time. Instead the time at which the
patient actually arrives in the clinical area should be accurately
documented as the official arrival time"
The exis...
I am delighted to see agreement between Taylor's article and the Dept
of Health guidance on recording of arrival times. Taylor et al recommend
that "the time the ambulance pulls up outside the department should no
longer represent a patient’s arrival time. Instead the time at which the
patient actually arrives in the clinical area should be accurately
documented as the official arrival time"
The existing Department of Health guidance[1] actually states that "the
time of arrival should be recorded by the clinician carrying out the
initial triage/ assessment or A&E reception whichever is earlier". This
may actually be later than physical arrival in the department and so may
reduce the total time by a few more minutes! The only time when this does
not occur is when the ambulance crew have not been able to hand over the
patients within 15 minutes of arrival. This later is designed to prevent
the patient getting lost in a gaming process between ambulance turnaround
and A&E total time.
Conflict of interest: The author is also the DH advisor who
contributed to the definition process.
References
1. Dept of Health SITREPS 2004-2005 Definitions and Guidance. London
2004.
While the results of this study appear very useful there are two issues. One is more of a theoretical nature: the interpretation of the 95% confidence interval; the second has something to do with external validity: potential selection bias.
Interpretation of the confidence interval:
In the abstract the authors state that "...the 95% limits of agreement were wide (–1.182 mmol...
While the results of this study appear very useful there are two issues. One is more of a theoretical nature: the interpretation of the 95% confidence interval; the second has something to do with external validity: potential selection bias.
Interpretation of the confidence interval:
In the abstract the authors state that "...the 95% limits of agreement were wide (–1.182 mmol/l to 1.394 mmol/l) — that is, 95% of differences will lie between these limits." This is wrong. The 95% confidence interval means that in 95% of the cases (i.e. if we would repeat such a study many, many times), the average(!) difference will lie within. In terms of clinical practice this means something completely different.
It seems that this observed mean bias and the wide confidence interval are cause by a single or maybe two outliers (patients #1 and #9). This makes the confidence intervals of this study not very trustworthy
Potential selection bias:
Over 10 months 50 patients were recruited. How many were admitted for cardiac arrest and what were the reasons for not having both analyses? Without this information we cannot interpret the findings.
In conclusion, this study is a first step but the findings should be validated in a prospective study before they can inform clinical practice.
I would like to thank Drs Glazebrook and Probst for pointing out a
potential source of confusion. I also considered gastric lavage
innapropriate management of overdose for multiple reasons, which gave me
cause to review the evidence. The fact it's use is still occasionally
suggested in clinical practice remains a personal concern.
At the time of the initial authorship of the BET concerned,
g...
I would like to thank Drs Glazebrook and Probst for pointing out a
potential source of confusion. I also considered gastric lavage
innapropriate management of overdose for multiple reasons, which gave me
cause to review the evidence. The fact it's use is still occasionally
suggested in clinical practice remains a personal concern.
At the time of the initial authorship of the BET concerned,
gastic lavage was being performed for a number of drug groups in
overdosage, in particular ions, NSAIDs and tricyclic antidepressants - for
which lavage was advocated due to the poor absorbtion of these drugs by
charcoal. BETs were performed on all these drug groups and the clinical
bottom line reflects a response to our initial clinical problem. In
response to the above letter all of the gastric lavage BETs on the website
will contain links to national poisons information service for up to date
advice. Clinical bottom lines are being updated to avoid the potential for
ambiguity.
I read Gilligans et als article with interest but was very surprised
initially at their lack of association of "boarding" with increased
mortality (1). I note in the discussion that they compared their findings
with Richardsons and stated that they did not find a similar outcome (2).
I would suggest that there are a number of reasons why this study did not
find similar findings to Richardson or Sprivulis who found strong...
I read Gilligans et als article with interest but was very surprised
initially at their lack of association of "boarding" with increased
mortality (1). I note in the discussion that they compared their findings
with Richardsons and stated that they did not find a similar outcome (2).
I would suggest that there are a number of reasons why this study did not
find similar findings to Richardson or Sprivulis who found strong
correlations between admission during overcrowded periods and death rates
(2,3).
Both those studies did a detailed analysis that compared all patients
admitted during periods of overcrowding (measured on a rising scale)
versus patients admitted during normal access periods. They did this using
short periods and direct measures of overcrowding so that data was not
muddied by days when part of the day may have had low levels of
overcrowding versus other periods of intense crowding. In addition they
adjusted all their findings for all potential confounders that could be
thought of e.g. time of day, day of week,public holiday, seasonal
variation,co-morbidity, age, etc and found that these factors did not
reduce the strong association of overcrowding versus mortality.
What seems clear from this studies data is that overcrowding was so
intense and overwhelming that there seemed to be very few periods during
this study when by any criteria the department would not be deemed
severely overcrowded (1). Therefore they were unable to compare periods of
overcrowding versus no overcrowding. Because this was not really measured
or discussed it is difficult to know how important an issue this is.
However there may well be a plateau effect in ED overcrowding v mortality
in that most of the late deaths are due to delayed /poor initial care
exacerbated by care away from a home ward after finally being admitted.
The degree to which your ED having 100% or 150% of cubicles tied up with
admitted patients at 9am impacts on this probable late effect may well be
relatively minor. There is also probably a point past which the ED is so
overcrowded that care cannot be made much more dysfunctional by additional
overload. These features of severe overcrowding need to be looked at
further. It is likely that past a certain point of dysfunction there is
only so much more you can do to make the patients outcome worse!
Perhaps this paper has discovered the plateau of death. However I
would very much doubt that it has found that the intolerable level of
overcrwding they describe is not having a serious effect on their patients
outcomes.
1) P Gilligan, S Winder, I Singh, V Gupta, P O Kelly, and D Hegarty
The Boarders in the Emergency Department (BED) study
Emerg Med J 2008; 25: 265-269
2) Richardson DB. Increase in patient mortality at 10 days associated
with emergency department overcrowding. Med J Aust 2006; 184: 213–16
3)Sprivulis PC, Da Silva J-A, Jacobs IG, et al. The association
between hospital overcrowding and mortality among patients admitted via
Western Australian emergency departments. Med J Aust 2006; 184: 208-212
I read with interest the article by Puranik & Gillham – Bilateral
fractured clavicles
with multiple rib fractures, Emerg Med J 2007; 24: 675. They are to be
congratulated on a successful outcome with such a challenging case.
However
they state that the acronym ORIF is an abbreviation of osteosynthesis of
irreducible fracture: it is an abbreviation of Open Reduction and Internal
Fixation.
I read with interest the article by Puranik & Gillham – Bilateral
fractured clavicles
with multiple rib fractures, Emerg Med J 2007; 24: 675. They are to be
congratulated on a successful outcome with such a challenging case.
However
they state that the acronym ORIF is an abbreviation of osteosynthesis of
irreducible fracture: it is an abbreviation of Open Reduction and Internal
Fixation.
Richard Loukota
Reference
1. Puranik G, Gillham N. Bilateral fractured clavicles with multiple
rib fractures,
Emerg Med J 2007; 24: 675.
The commentary on early warning scores in the ED presents an
interesting viewpoint on their use. NCEPOD, NICE and CEMACH all recommend
the use of track and trigger systems in acute hospital settings, a
Department of Health review found that most NHS trusts were using
aggregate weighting systems such as Modified Early Warning Scores (MEWS)
(1). MEWS have been validated in the medical and surgical ward s...
The commentary on early warning scores in the ED presents an
interesting viewpoint on their use. NCEPOD, NICE and CEMACH all recommend
the use of track and trigger systems in acute hospital settings, a
Department of Health review found that most NHS trusts were using
aggregate weighting systems such as Modified Early Warning Scores (MEWS)
(1). MEWS have been validated in the medical and surgical ward settings
with paediatric and obstetric specific scores also validated in their own
specialist settings (2). These scoring systems are well recognised and
utilised by these specialities and provide a common ground for
communication of physiological abnormality.
As noted there have been few studies based within the ED to validate
the use of these scoring systems in this setting. Since the systematic
review by Gao et al, 11 further studies with the ED setting and 3 within
the pre-hospital setting have been published. These studies have shown
significant increases in the odds ratios for mortality and need for higher
dependency care as MEWS increases; with most studies identifying MEWS
>/= 4 as the optimum cut off. Area under the receiver operator curves
range between 0.72 - 0.96 for MEWS in the ED population, demonstrating
acceptable to excellent predictive ability (3, 4).
The validation in the ED study by Subbe et al failed to demonstrate
significant benefit overall in using MEWS in addition to the Manchester
Triage Scale(MTS)(5). However, in the group of ED patients who were not
initially recognised as needing a higher level care and subsequently were
transferred from the ward to ITU, using MEWS would have detected an
additional 7/49 above MTS. The numbers in this study requiring higher
level care were low but this indicates a potential significant benefit
above previous standard triage practice alone.
Whilst a universal EWS system cannot cover our entire patient
population and does not replace clinical judgement, it does provide a
framework for recognition of physiological abnormality and the
communication of this to other specialities. Predictive value can be
increased by excluding use in those known to have critical conditions
regardless of physiology e.g. Acute MI's, Head injury. In the busy ED,
MEWS can be utilised to direct senior review towards those needing early
decision making on need for higher dependency care, directed treatment and
resuscitation.
Dr S. Dorrian
SpR Emergency Medicine
Birmingham Heartlands Hospital
1. Department of Health and NHS Modernisation Agency (2003) The
National Outreach Report. Department of Health, London
2. Subbe CP, Kruger M, Rutherford P, Gemmel L, Validation of a
modified Early Warning Score in Medical admissions QJM 2001; 94:521 - 526
3. Lam TS et al Validation of a Modified Early Warning Score (MEWS)
in emergency department observation ward patients Hong Kong Journal of
Emergency Medicine 2006; 60(6): 547 - 553
4. Vorwerk et al Prediction of mortality in adult emergency
department patients with sepsis Emergency Medicine Journal 2009; 26: 254 -
258
5. Subbe et al Validation of physiological scoring systems in the
accident and emergency department Emergency Medicine Journal 2006; 23:841
- 845
Professor Deacon and colleagues report the precision with which the
Priority Dispatch Corporation’s ProQA™ call interrogation software
detects Acute Coronary Syndrome (ACS) amongst ‘999’ calls from the
Southampton area (1). They analysed an 8 month sample of 42,657 emergency
calls and identified 3368 patients with a ‘chief complaint’ of ‘chest
pain’ as determined by the use of ProQA™ . The author...
Professor Deacon and colleagues report the precision with which the
Priority Dispatch Corporation’s ProQA™ call interrogation software
detects Acute Coronary Syndrome (ACS) amongst ‘999’ calls from the
Southampton area (1). They analysed an 8 month sample of 42,657 emergency
calls and identified 3368 patients with a ‘chief complaint’ of ‘chest
pain’ as determined by the use of ProQA™ . The authors were then able to
access the MINAP (2) data set for Southampton General Hospital and
identify which patients subsequently had an ACS confirmed. Cross
referencing these two data sets revealed 263 patients with a ‘proven’ ACS,
187 of which had been ‘correctly’ identified.
On the basis of these results, the authors calculated that the
sensitivity of ProQA™ in detecting ACS in this population was only 71%
with a specificity of 92.5% and a positive predictive value of 5.6% (95%
CI 4.8 to 6.4%). The results, as I understand them, are reproduced in
table 1 (there are typographical errors in the published table). The
authors conclude that the sensitivity and positive predictive value of
ProQA™ “does not enable accurate identification of patients with ACS”.
There are three points that merit further discussion which may
fundamentally influence our interpretation of these results.
Firstly, the 95% confidence interval for the sensitivity of ProQA™
(the proportion of people with ACS who are identified) lies between 66 and
77%. This sensitivity is based on the true positives – the 187 patients
with both chest pain and ACS. However, it may not be wholly appropriate to
use the ‘chest pain’ chief complaint determinant alone as a measure of the
performance of ProQA™. The software allows additional subdivision of all
calls according to clinical urgency. The authors allude to this when they
indicate that 230 of the 263 patients with confirmed ACS had actually been
categorised as having an immediate threat to life by ProQA™ – thus
triggering an urgent (Category A) response – regardless of whether chest
pain was the chief complaint. The sensitivity of ProQA™ in identifying
patients with ACS who could benefit from a rapid response could therefore
be as high as 87% (230/263) with 95% CI between 83% and 92%.
Secondly, for rare events, the major determinant of predictive value
is the prevalence of the condition in the population tested. No matter how
specific the test is, if the population is at low risk of having the
disease, positive results are more likely to be false positives and the
predictive values will be low. In this study, the apparent prevalence of
ACS is 0.61% (263 / 42657) which, although three times higher than a
general population estimate (3), appears low for a sample of 999 calls. An
argument could be made that it is the denominator of 42,657 which causes
the problem here. This number could be reduced by excluding the large
number of calls that would clearly have been of no relevance to ACS (e.g.
minor wounds and injuries). Reduction of the denominator value would
increase prevalence and positive predictive value. The likelihood ratio is
less likely to be influenced by prevalence and it probably better reflects
the complexity of the ProQA™ process. For this data set, a positive ProQA™
result would be eight to ten times as likely to be seen in someone with
ACS as opposed to someone without ACS (Likelihood = (sensitivity/(1-
specificity)) = 9.5 with 95% CI: 8.7 to 10.3).
Thirdly, the trade off between acceptable sensitivity and specificity
requires us to weigh the consequences of missing ACS (a false negative)
against the consequences of erroneously dispatching resources (a false
positive). In making these judgements, the context of this study is
important. Accurate and rapid deployment of thrombolysis capable
paramedics is considered key to the pre-hospital management of ACS and the
efficiency of such deployment is retrospectively scrutinized by local,
regional and national authorities. The emphasis is therefore on high
sensitivity of any initial call handling system. The higher the
sensitivity, the greater the ACS detection rate and the lower the false
negative rate.
Sensitivity tends to be favoured at the expense of specificity when
the penalty associated with missing a case is high – as is often argued
for ACS. On the other hand, specificity should be favoured relative to
sensitivity when the cost or risks associated with a false positive are
high. One might argue that in a climate where it is still the clinician
who determines actual treatment (not ProQA™), Ambulance Services are not
the last line of defense, most hospital Coronary Care Units and Emergency
Departments have clearly defined rapid assessment and treatment pathways
for ACS and thrombolysis capable paramedics are still a relatively scarce
resource, we should favour a caller interrogation system with a high
specificity and low number of false positives. If this is the case, a
sensitivity of up to 77% (and possibly as high as 92%) and a specificity
of up to 93% (upper 95% CI) may be perfectly reasonable – and as good as
it gets!
Roderick Mackenzie
References
1. Deakin CD, Sherwood DM, Smith A, Cassidy M. Does telephone triage
of emergency (999) calls using advanced medical priority dispatch (AMPDS)
with Department of Health (DH) call prioritisation effectively identify
patients with an acute coronary syndrome? An audit of 42 657 emergency
calls to Hampshire Ambulance Service NHS Trust. Emergency Medicine Journal
2006;23:232-235.
3.National Institute for Clinical Excellence. Technology Appraisal
No. 47. Guidance on the use of glycoprotein IIb/IIIa inhibitors in the
treatment of acute coronary syndromes. September 2002.
I do fully agree with the authors that acute tension viscerothorax
should be included in the differential diagnosis of blunt thoracoabdominal
trauma as immediate intervention can be life saving.
On the therapeutic point of view however I have another opinion. In
our experience with two cases of acute posttraumatic tension gastrothorax
decompression by means of a nasogastrical tube was impos...
I do fully agree with the authors that acute tension viscerothorax
should be included in the differential diagnosis of blunt thoracoabdominal
trauma as immediate intervention can be life saving.
On the therapeutic point of view however I have another opinion. In
our experience with two cases of acute posttraumatic tension gastrothorax
decompression by means of a nasogastrical tube was impossible due to the
anatomical changes with the intrathoracic position of the stomach and the
trapped air. One can always try to deflate the stomach in this way but we
think that emergency surgical repair will be necessary in most cases.
Yours sincerely,
LJM Mortelmans
Reference
1. Acute post-traumatic tension gastrothorax, a tension pneumothorax-like
injury. LJM Mortelmans, GCY Jutten and L Coene. EUJEM 2003; 10:344-46.
Nearly 20 years ago I was fortunate enough to be present in the Isle
of Man when Tom Hamilton gave his prestigious Maurice Ellis lecture
entitled Not Cas, not A&E but Emergency Medicine.
Some years ago myself and one John Heyworth, now president elect of
the College of Emergency Medicine, castigated the British Medical Journal
for publishing a paper referring to 'casualty'. [1] How disappointing
this month...
Nearly 20 years ago I was fortunate enough to be present in the Isle
of Man when Tom Hamilton gave his prestigious Maurice Ellis lecture
entitled Not Cas, not A&E but Emergency Medicine.
Some years ago myself and one John Heyworth, now president elect of
the College of Emergency Medicine, castigated the British Medical Journal
for publishing a paper referring to 'casualty'. [1] How disappointing
this month to see EMJ publish this paper which uses the the term Casualty
as well as Accident & Emergency to describe an Emergency department.
[2] Furthermore I found two other papers in this edition referring to
'Casualty' ! [3][4]
The journal, now as the flagship of the college and having taken over
that responsibility from the now defunct Britsh Association for Emergency
Medicine, should be more vigilant in proof reading papers so that the
specialty and the young College can be optimally portrayed in these
changing times.
1) Rapid assessment of chest pain. "Casualty" is outdated term for
"emergency medicine". Ryan JM, Heyworth J, BMJ. 2001 Sep 15;323(7313):586-
7.
2) Patterns of ophthalmological complaints presenting to a dedicated
ophthalmic Accident & Emergency department: inappropriate use and
patients’ perspective S Hau, A Ioannidis, P Masaoutis, and S Verma Emerg
Med J 2008; 25: 740-744
3) Traumatic eversion of the umbilicus: what lies beneath?
N F S Watson, H Z Butt, J F Abercrombie, I Ahmed Emergency Medicine
Journal 2008;25:772;
4) Tooth remnant in non-venomous snake bite on the face: a rare
occurrence A Kirwadi, V B Pakala, D Suresh Kumar, and P A Evans. Emerg Med
J 2008; 25: 782
I read with interest the case report “Mercury: Is it elemental my dear Watson” by M Poulden. [1] In 1993, Dr Roden and I reported a case of deliberate self injection of mercury resulting in abscess formation and mercuric emboli to the lungs.[2]
In our case a 27-year-old doorman of a local casino presented with a swelling of the arm. (He was a keen body builder 1.90m in height and weighed 107Kgm). O...
I read with interest the case report “Mercury: Is it elemental my dear Watson” by M Poulden. [1] In 1993, Dr Roden and I reported a case of deliberate self injection of mercury resulting in abscess formation and mercuric emboli to the lungs.[2]
In our case a 27-year-old doorman of a local casino presented with a swelling of the arm. (He was a keen body builder 1.90m in height and weighed 107Kgm). On the flexor aspect of his forearm there was a 4 x 5cm fluctuant swelling. The Casualty Officer drained this abscess and out came mercury! A radiograph of the forearm showed the mercury and radiographs of the skull and chest demonstrated micro emboli.
Serial blood and tissue mercury levels were raised but not toxic. We treated him with penicillamine and excised the abscess on the forearm under a general anaesthetic. He remained well. He denied putting the mercury in himself and revelled in any attention.
Three months later he returned complaining of a “head injury”. There was a small wound on his forehead. Radiographs showed a bullet in his skull and CT showed a large frontal haematoma. He was operated on by neurosurgeons and then referred to the psychiatrists.
Deliberate poisoning by self injection of mercury as a suicide attempt was first reported by Umber (1923).[3] There are about 30 such cases in the literature with 3 fatalities reported. However deliberate injection of mercury to obtain strength has also been reported by Celli & Khan ,1976. [4] Our patient admitted eventually that the gunshot wound was a suicide attempt and the injection has been thought to give extra strength to body builders.
These two cases, the ingestion reported in Emergency Medicine and injection reported in Injury, illustrate that the emergency doctor has to be ever vigilant as some of our patients do strange things. In both cases there was a delay in obtaining the blood mercury levels. The patient who ingested mercury had a higher level of mercury than the one who injected himself! There is little correlation between the volume of mercury injected and the outcome. 2cc has been fatal (Johnson & Koumides 1967 [5]) and 20cc non fatal (Celli & Khan 1976 [4]).
The term, “Mad as a hatter” is thought to have derived from madness induced in hatters from contact with mercury. However those who ingest or inject mercury can hardly be termed “normal”.
References
(1) Poulden M. Mercury: Is it elemental my dear Watson?
Emerg Med J 2002;19:82-83.
(2) Roden R, Fraser-Moodie A. Self-injection with mercury.
Injury 1993; 24(3):191-2.
(3) Umber F Quecksilber. Quecksilber – Embolien des lehender durch intraverose injektion vol metallis chen silber. Med Klin 1923 19.
(4) Celli Bard Khan MA Mercury Embolisation of the lung. N Engl J Med 1976;295:883.
(5) Johnson HRM and Koumides O (1967) Unusual case of mercury poisoning. BMJ 1967;1340.
Dear Editor,
I am delighted to see agreement between Taylor's article and the Dept of Health guidance on recording of arrival times. Taylor et al recommend that "the time the ambulance pulls up outside the department should no longer represent a patient’s arrival time. Instead the time at which the patient actually arrives in the clinical area should be accurately documented as the official arrival time" The exis...
Dear Editor,
While the results of this study appear very useful there are two issues. One is more of a theoretical nature: the interpretation of the 95% confidence interval; the second has something to do with external validity: potential selection bias.
Interpretation of the confidence interval:
In the abstract the authors state that "...the 95% limits of agreement were wide (–1.182 mmol...
Dear Editor
I would like to thank Drs Glazebrook and Probst for pointing out a potential source of confusion. I also considered gastric lavage innapropriate management of overdose for multiple reasons, which gave me cause to review the evidence. The fact it's use is still occasionally suggested in clinical practice remains a personal concern.
At the time of the initial authorship of the BET concerned, g...
I read Gilligans et als article with interest but was very surprised initially at their lack of association of "boarding" with increased mortality (1). I note in the discussion that they compared their findings with Richardsons and stated that they did not find a similar outcome (2). I would suggest that there are a number of reasons why this study did not find similar findings to Richardson or Sprivulis who found strong...
I read with interest the article by Puranik & Gillham – Bilateral fractured clavicles with multiple rib fractures, Emerg Med J 2007; 24: 675. They are to be congratulated on a successful outcome with such a challenging case. However they state that the acronym ORIF is an abbreviation of osteosynthesis of irreducible fracture: it is an abbreviation of Open Reduction and Internal Fixation.
Richard Loukota...
Dear Sir
The commentary on early warning scores in the ED presents an interesting viewpoint on their use. NCEPOD, NICE and CEMACH all recommend the use of track and trigger systems in acute hospital settings, a Department of Health review found that most NHS trusts were using aggregate weighting systems such as Modified Early Warning Scores (MEWS) (1). MEWS have been validated in the medical and surgical ward s...
Dear Editors,
Professor Deacon and colleagues report the precision with which the Priority Dispatch Corporation’s ProQA™ call interrogation software detects Acute Coronary Syndrome (ACS) amongst ‘999’ calls from the Southampton area (1). They analysed an 8 month sample of 42,657 emergency calls and identified 3368 patients with a ‘chief complaint’ of ‘chest pain’ as determined by the use of ProQA™ . The author...
Dear Editor,
I do fully agree with the authors that acute tension viscerothorax should be included in the differential diagnosis of blunt thoracoabdominal trauma as immediate intervention can be life saving.
On the therapeutic point of view however I have another opinion. In our experience with two cases of acute posttraumatic tension gastrothorax decompression by means of a nasogastrical tube was impos...
Nearly 20 years ago I was fortunate enough to be present in the Isle of Man when Tom Hamilton gave his prestigious Maurice Ellis lecture entitled Not Cas, not A&E but Emergency Medicine.
Some years ago myself and one John Heyworth, now president elect of the College of Emergency Medicine, castigated the British Medical Journal for publishing a paper referring to 'casualty'. [1] How disappointing this month...
Dear Editor
I read with interest the case report “Mercury: Is it elemental my dear Watson” by M Poulden. [1] In 1993, Dr Roden and I reported a case of deliberate self injection of mercury resulting in abscess formation and mercuric emboli to the lungs.[2]
In our case a 27-year-old doorman of a local casino presented with a swelling of the arm. (He was a keen body builder 1.90m in height and weighed 107Kgm). O...
Pages