We read this intriguing case report with great interest. However, it
contained two specific weaknesses which undermined its strength, leaving
it inconclusive. The critical point is not whether caffeine excess might
cause seizures (this is known), or the theoretical pathophysiology
(comprehensively discussed in the article), but whether it was the
definitive cause of seizures in this case.
We read this intriguing case report with great interest. However, it
contained two specific weaknesses which undermined its strength, leaving
it inconclusive. The critical point is not whether caffeine excess might
cause seizures (this is known), or the theoretical pathophysiology
(comprehensively discussed in the article), but whether it was the
definitive cause of seizures in this case.
Firstly, without measuring the serum caffeine concentration (or at
least its metabolite, theophylline - a widely available assay in acute
hospitals for therapeutic purposes) it is impossible to know how much
credence to place on the role of caffeine in this case.
Secondly, there was no mention of serum sodium, potassium or
creatinine kinase measurements. Sodium and potassium gradients across the
cell membrane exert a major effect on the stability of excitable cells,
especially neurone and skeletal muscle respectively[1]. Potassium
gradients are affected directly by hydrogen ion concentrations.
Hypokalaemia predisposes to tachyarrhythmias, potentially leading to
seizures through secondary cerebral anoxia. There is a complex interplay
between electrolyte disturbances (especially hypokalaemia and acid-base
disturbance), cardiac arrhythmias and seizures - each predisposing to the
others, and in turn being predisposed to by the others. Arguably, the
biochemical data in this case were consistent with recent seizure
activity, irrespective of its precipitant.
In a patient with a previous cerebral infarct and 'vascular
encephalopathy', both significant risk factors for seizure, it is very
difficult to know what part each of the relevant contributory factors
played. The reference cited for seizure incidence post-stroke [2] looks
at the influence of major co-morbidities (which this patient did not
apparently have) on the outcome, in particular mortality, and without
mentioning seizure per se. That said, the incidence of idiopathic
epilepsy is well known to vary greatly by age and other factors, none of
which was discussed quantitatively for this case.
As the report says, any seizure occurs when the seizure threshold is
lowered sufficiently by the prevailing circumstances. With so many
interdependent co-variates in this case (underlying structural brain
lesion, past history of substance abuse and possible withdrawal, acute
kidney injury, electrolyte and acid-base disturbances, as well as possible
rhabdomyolysis) in addition to the possibility of caffeine, it is
impossible to judge the latter's likely contribution. Sadly this adds no
weight to the quoted case report [3] which also omitted relevant
toxicological data.
A case report needs the relevant data to allow a conclusive judgement
to be made!
[1] Goldstein LB et al. Charlson Index comorbidity adjustment for
ischaemic stroke outcome studies. Stroke 2004;35:1941-5
Other authors: Dr S Rawstorne - Medical Director, Great Western Ambulance Service NHS Trust and Chair of the Directors of Clinical Care; Dr A Walker - Medical Director, Yorkshire Ambulance Service NHS Trust; Dr A Carson - Medical Director, West Midlands Ambulance Service; Dr John Black – Medical Director, South Central Ambulance Service NHS Trust; Dr Kyee Han – Medical Director, North East Ambulance Service NHS Trust ...
Other authors: Dr S Rawstorne - Medical Director, Great Western Ambulance Service NHS Trust and Chair of the Directors of Clinical Care; Dr A Walker - Medical Director, Yorkshire Ambulance Service NHS Trust; Dr A Carson - Medical Director, West Midlands Ambulance Service; Dr John Black – Medical Director, South Central Ambulance Service NHS Trust; Dr Kyee Han – Medical Director, North East Ambulance Service NHS Trust
Dear Editor
We, like many others, read the paper from O'Keeffe et al1 with great
interest as this area is of particular relevance to NHS Ambulance Services
nationally, particularly as this is both an emotive topic but also one
which has significant relevance in relation to the ongoing debate around
response times.
It is disappointing that within the paper the key message, namely
that it is not cost-effective to fund services to this level based upon
NICE criteria for cost effectiveness of a treatment, is lost behind some
of the more sensational figures. Whilst this is highlighted in the
abstract conclusion the message gets lost within the text where figures
highlighted in the article such as a 24% relative survival rate are
potentially misleading when this translates to a 0.6% actual increase, a
total of 149 patients nationally per year.
There are some other issues that should be highlighted. Firstly the
dataset is based upon consecutive calls for patients either unconscious,
not breathing, or having chest pain from 5 services for 5 years. From this
1258 patients are identified as out of hospital cardiac arrest (OHCA).
What is not mentioned is any context - specifically how many patients this
is a subset of. Given that chest pain alone is one of the top three
reasons for an ambulance to be called nationally it is likely that the
number of cases that this is a subset of is very large (in the order of
hundreds of thousands of cases/year for the services evaluated).
Secondly the quoted survival improvements are that a less than 6
minute response can increase survival by greater than 5%. If we assume a
baseline response time of 8 minutes in these cases the costing based on a
1 minute reduction seem inappropriate - surely it should be a 2 minute
reduction otherwise the cost calculations will be very underestimated. It
is also important to reflect that the national standard is for an 8 minute
response in 75% of cases not 100% and therefore what additional resource
would be required to manage this gap?
Finally there are some specific data issues. It should be noted that
the costing assumptions are based upon 1998 figures which will now be
highly unrepresentative of current costs - fuel alone for the relative
number of cases will have hugely increased the cost as well as the change
in staffing costs due to Agenda For Change therefore we would suggest this
to be a significant under-estimate of current cost which would further
emphasise the lack of cost-effectiveness. We do not feel that the current
configuration of services would be likely to affect these costs compared
to the previous 32 service configuration. Data quality is noted in the
limitations however the implication is that this could only artificially
improve the reported response time results, in fact it could also
potentially worsen them which should be considered. It is also unclear as
to what response types are considered as the paper only refers to
Paramedics however the Ambulance service utilises a range of clinicians to
deliver care, particularly defibrillation, including a growing number of
Community First responders who provide a key role in early basic life
support and defibrillation.
It is of note that the paper states that emphasis should be placed
upon the quality of care rather than simply response times. The NHS
Ambulance Service Directors of Clinical Care across the UK (national
Medical Directors group), have focussed on quality of care through the
National Clinical performance Indicators and now the Ambulance Clinical
Quality Indicators and it is also of note that in the time since the data
was taken for this study resuscitation guidance has changed twice
specifically to improve the quality of cardiopulmonary resuscitation.
With such an important article we feel that there is a significant
risk that the way the figures have been presented could be easily
misinterpreted leading to a lack of understanding by external commentators
on the reality of managing patients in out of hospital cardiac arrest and
the benefit of investment purely to decrease response times.
1 Colin O'Keeffe, Jon Nicholl, Janette Turner, Steve Goodacre, Role of ambulance response times in the survival of patients with out-of-hospital cardiac arrest, Emerg Med J 2011; 28: 703-706
Thank you for taking the time to read and respond to our paper and
for usefully highlighting the possible application of the Kendrick
Extrication Device (KED) in such circumstances.
We can confirm that had nebulisation been required prior to
extrication from the premises that the application of the KED would have
been considered. In our case however the initial position of the patient
enabled a simple rearwar...
Thank you for taking the time to read and respond to our paper and
for usefully highlighting the possible application of the Kendrick
Extrication Device (KED) in such circumstances.
We can confirm that had nebulisation been required prior to
extrication from the premises that the application of the KED would have
been considered. In our case however the initial position of the patient
enabled a simple rearward immobilisation onto a back board (with no risk
of rotational movement) one of the "several acceptable means of back
support" recommended in current UK prehospital care guidance.(1)
The immobilisation system and device was selected and applied prior
to deterioration and on the presumption that the acute alcohol
intoxication was masking a head injury. We were therefore keen to
immobilise and extricate promptly. The authors would have been required
to predict the 'type' of deterioration and subsequent need for
nebulisation for the KED to have been applied 'prophylactically'.
Furthermore, the paper you reference(2) correctly points out that the
fitting of the KED takes time and recommends its use only "in the event of
non-life-threatening injuries and if the vital signs are stable". Our
patient became clinically unstable post immobilisation, with oxygen
saturations decreasing markedly during extrication. Had the decision been
made to apply the KED after full immobilisation on the back board
(enabling the patient to sit upright) this, undoubtedly, would have
delayed treatment and transportation to definitive care. As the
application of the KED can extend on scene times, the authors would be
cautious in supporting its prophylactic use 'just in case' the patient
required to be positioned for nebulisation.
Current guidelines(1) and recent research(3) suggest there are a
number of immobilisation options available with the most appropriate often
being determined by the circumstances. Our improvised nebulisation device
enabled the patient to remain supine, not 'prone' as you suggested
(achieving uncompromised spinal care), receive nebulised salbutamol
(effectively treating a bilateral expiratory wheeze), and be transported
expeditiously (without delay) to the emergency department for definitive
care.
1. Joint Royal College Ambulance Liason Committee. UK Ambulance
Service Clinical Practice Guidelines (2006): Neck and Back Trauma. London:
JRCALC, 2006.Castellano, J. (2007). Prehospital management of spinal cord
injuries. Emergencies. 19 (1), 25-31.
2. Castellano, J. (2007). Prehospital management of spinal cord
injuries. Emergencies. 19 (1), 25-31.
3. Luscombe MD, Williams J. Comparison of a long spinal board and
vacuum mattress for spinal immobilisation. Emerg Med J 2003;20:476-478.
Thank you for taking the time to read and respond to our paper. The
authors are very grateful for your information on the 'Aero Neb Go Mask'.
The Scottish Ambulance Service (SAS) currently use the Lifecare micro neb
III)which does not enable nebulisation in the supine position. Having
viewed the Aero Neb Go Mask it would appear that it would have been
effective in our case. The authors would be interested to know whethe...
Thank you for taking the time to read and respond to our paper. The
authors are very grateful for your information on the 'Aero Neb Go Mask'.
The Scottish Ambulance Service (SAS) currently use the Lifecare micro neb
III)which does not enable nebulisation in the supine position. Having
viewed the Aero Neb Go Mask it would appear that it would have been
effective in our case. The authors would be interested to know whether
the head hugger chin strap and/or collar could interfere with Aero Neb Go
Mask placement in any way.
With reference to the use of a catheter mount as an alternative to
the corrugated tubing from a venturi, this was considered at the time of
the incident. The venturi corrugated tubing used had an internal diameter
of 22mm. Both the Lifecare micro nebuliser and Lifecare duo oxygen mask
connections have external diameters of 22mm providing a secure fit to the
corrugated tubing. The 'Intersurgical' catheter mount used by the SAS also
has a 22mm connector which fits snugly to the duo oxygen mask.
Unfortunately the opposite end (normally attached to an endotracheal tube)
has a 15mm connector. This prevents it from being attached to the micro
neb III. An ET tube would therefore not have worked in our case.
These discrepancies emphasise the need, for those interested in
preparing for this scenario, to check these compatibilities prior to
requirement.
Furthermore, the 'Intersurgical' catheter mount is slightly longer
and significantly narrower than the system outlined in the case report.
These differences may impact on drug deposition and efficacy, as
discussed.
Ultimately, our improvised device provides an additional option for
the prehospital care provider. A degree of flexibility is afforded
enabling the micro nebuliser to be positioned at either side of the
individuals neck/head. This may prove useful in the often awkward
situations experienced in the pre-hospital environment i.e. entrapments,
during immobilisation and where space around the head is limited.
We thank Dr. Lopez and colleagues for this large prospective study
evaluating the benefit of a triage flowchart to rule out acute coronary
syndrome (ACS) in the emergency department1. They apply a 5 steps
flowchart to classify patients as "triage non-ACS": i.e. patients less
than 40 years old, absence of diabetes, no previously known coronary
artery disease, non-oppressive and non-retrosternal pain. In their sample
of 4...
We thank Dr. Lopez and colleagues for this large prospective study
evaluating the benefit of a triage flowchart to rule out acute coronary
syndrome (ACS) in the emergency department1. They apply a 5 steps
flowchart to classify patients as "triage non-ACS": i.e. patients less
than 40 years old, absence of diabetes, no previously known coronary
artery disease, non-oppressive and non-retrosternal pain. In their sample
of 4231 patients, they report for this triage rule a specificity and
positive predictive value (PPV) to rule out ACS of 100% [100-100], without
any missed ACS. Their work is to be applaused as ruling out ACS in the
emergency department is of great concern. However we question its
application and generalization. In our recently published study 2, we
enrolled 317 consecutive patients with chest pain suspect of ACS.
Similarly to their sample, mean age was 57 years (+/- 17). In a post-hoc
analysis, we applied this 5 steps triage. Thirty two (10%) patients were
in the "triage non-ACS" group, in whom 2 (6%) of them were true ACS. Thus,
PPV was 94% [95% confidence interval [90-99]. Because outcomes of ACS may
be severe, the PPV to rule out this diagnosis must be of 100%. We have to
remind the debate on the Pulmonary Embolism Rule-out Criteria (PERC), that
has been shown to identify the absence of Pulmonary Embolism (PE) with a
PPV of 98% 3,even less when a external validation was applied 4. This
value could not safely identify very low risk patients in whom PE can be
ruled out without additional testing. Likely, we strongly suggest the use
of fast and reliable biomarker (troponin) to reach a perfect specificity
and PPV for ruling out ACS, as recently suggested 5. Therefore, we think
that more studies are warranted to assess a potential benefit of this 5
steps triage.
1. Lopez B, Sanchez M, Bragulat E, et al. Validation of a triage
flowchart to rule out acute coronary syndrome. Emerg Med J. 2011;28:841-
846.
2. Freund Y, Chenevier-Gobeaux C, Bonnet P, et al. High-sensitivity versus
conventional troponin in the emergency department for the diagnosis of
acute myocardial infarction. Crit Care. 2011;15:R147.
3. Kline JA, Courtney DM, Kabrhel C, et al. Prospective multicenter
evaluation of the pulmonary embolism rule-out criteria. J Thromb Haemost.
2008;6:772-780.
4. Hugli O, Righini M, Le Gal G, et al. The pulmonary embolism rule-out
criteria (PERC) rule does not safely exclude pulmonary embolism. J Thromb
Haemost. 2010;9:300-304.
We were concerned to read the paper by Figgan et al (1) demonstrating
the ambulance clinicians lack of compliance with prehospital guidance
during assessment of chest pain presentations. Chauhan et al (2) also
appropriately highlight the need for accurate assessment of posterior
myocardial infarction (PMI) and that this particular presentation of Acute
Coronary Syndrome (ACS) appears to have received little attention in p...
We were concerned to read the paper by Figgan et al (1) demonstrating
the ambulance clinicians lack of compliance with prehospital guidance
during assessment of chest pain presentations. Chauhan et al (2) also
appropriately highlight the need for accurate assessment of posterior
myocardial infarction (PMI) and that this particular presentation of Acute
Coronary Syndrome (ACS) appears to have received little attention in past
JRCALC guidance. Of interest was the statement regarding isolated PMI
accounting for up to 7% of all STEMI. A recent paper (3) focussing on the
challenges around the pre-hospital treatment and diagnosis of Left Bundle
Branch Block (LBBB) suggested LBBB was also an uncommon presentation of
acute coronary syndrome. Others have documented the prevalence of LBBB
ranging between 2.4% to 6.1%.(4&5) However, despite being so infrequently
encountered, LBBB has been included in Scottish Ambulance Service (SAS)
thrombolysis guidelines since 2005/06.(3) Additional education and
training was provided during its introduction. Challenges, however, have
been faced in treating this less than common presentation. SAS audit data
during 2008/09 demonstrate that of the 61 (2.5%) patients diagnosed with
LBBB and ACS just 0.6% (n=1) received prehospital thrombolysis.3
Anecdotal evidence suggested that the low incidence of thrombolysis may
have been due to the inability of ambulance clinicians to determine
whether the presenting ECG changes were new or old. As a result they
erred on the side of caution and did not initiate thrombolysis.
We completely agree with the recommendation by Chauhan et al (2) to
expand education and training for ambulance clinicians on the less common
presentations of ACS such as PMI and for its future inclusion in JRCALC
guidelines. As suggested, isolated PMI is relatively straightforward to
diagnose with Ambulance clinicians requiring some additional education
around lead positioning and ECG interpretation. However in addition to
this, ambulance services need to ensure reliable telemetry systems are in
place and that there are robust decision support systems established with
expert clinicians in Coronary Care Units. Without this multi/inter-
professional approach to emergency care it is unlikely that education or
the inclusion of PMI in JRCALC guidance will, on their own, facilitate a
change in practice and improvement in care.
Ref
1. Figgis K, Slevin O, Cunningham JB. Identification of paramedics
compliance with clinical practice guidelines for the management of chest
pain. Emerg Med J 2010;27:151-5.
2. Chauhan A, Khan JN, Khan JM, Varma C. Prehospital assessment and
management of chest pain needs improving. Emerg Med J doi:10.1136/emermed-
2011-200625
3. Fitzpatrick D, McLean S. Reperfusion of the old or new: left
bundle branch block? Journal of Paramedic Practice, Vol. 2, Iss. 2, 26 Feb
2010, pp 50 - 55
4. Kontos MC, McQueen RH, Jesse RL et al. Can myocardial infarction
be rapidly identified in emergency department patients who have left
bundle branch block? Ann Emerg Med 2001. 37(5): 431-8
5 Edhouse JA, Sakr M, Angus J et al. Suspected myocardial infarction
and left bundle branch block: electrocardiographic indicators of acute
ischaemia. J Accid Emerg Med 1999.16(5): 331-5
Thankyou for your informative article investigating the use of
ketamine in prehospital intubation.
From your article it seems clear that data was collected identifying
who undertook the intubations in each case; I was wondering if there was
any significant difference in success rates, number of attempts and
complication rates between paramedic and physician intubations?
Thankyou for your informative article investigating the use of
ketamine in prehospital intubation.
From your article it seems clear that data was collected identifying
who undertook the intubations in each case; I was wondering if there was
any significant difference in success rates, number of attempts and
complication rates between paramedic and physician intubations?
If this data is available I'm sure it would be a valuable
contribution to the ongoing debate regarding prehospital intubation.
In their informative article, Fitzpatrick, Brady and Maguire (1) demonstrate an excellent method for delivering nebulised medication to a supine patient. The authors also state they are unaware of any commercially available devices able to nebulise a supine patient. Although I have no personal experience with the mask in question, the Aero Neb Go mask, produced by Romsons International, utilizes an elbow adapter, allowing neb...
In their informative article, Fitzpatrick, Brady and Maguire (1) demonstrate an excellent method for delivering nebulised medication to a supine patient. The authors also state they are unaware of any commercially available devices able to nebulise a supine patient. Although I have no personal experience with the mask in question, the Aero Neb Go mask, produced by Romsons International, utilizes an elbow adapter, allowing nebulised drugs to be administered to supine patients.
A similar system to the one described by the authors, using a flexible ET catheter mount instead of the corrugated tubing, would also be effective, although may be more expensive. There is also the option of using the commercially available T-piece with the catheter mount to allow nebulised drugs to be administered to supine patients who require ventilatory support.
(1) Fitzpatrick, D., Brady, J.A. and Maguire, D. (2011). Prehospital improvisation of standard oxygen therapy equipment to facilitate delivery of a bronchodilator in a supine patient. EMJ Online First.
I would be very grateful if the author of this clinical image could
be given the opportunity to describe the clinical aspects of the case.
Pelvic splints are applied in the pre-hospital environment for
suspected pelvic fractures and should be removed by the emergency
department when imaging has excluded an unstable fracture pattern and when
the patient is haemodynamically stable.
I would be very grateful if the author of this clinical image could
be given the opportunity to describe the clinical aspects of the case.
Pelvic splints are applied in the pre-hospital environment for
suspected pelvic fractures and should be removed by the emergency
department when imaging has excluded an unstable fracture pattern and when
the patient is haemodynamically stable.
Could the author please inform readers:
How long was the splint applied before the complications arose?
Was the pelvic belt a recognised commercial splint?
What was the pelvic fracture on imaging and was this a stable injury?
Was the patient haemodynamically stable?
This information will effect our interpretation of the
appropriateness of management
Although the gold standard of immobilisation is in a prone position,
with a C collar and a vaccum matress the use of a device such as the
kendrick extraction device (KED) is one to be considered in patients such
as this. It provides almoast complete immobilisation from the neck to the
torso. (1) This allows the patient to be sat up at a 30-40 degree angle to
allow for best ventilation.(2) This same method can be used with...
Although the gold standard of immobilisation is in a prone position,
with a C collar and a vaccum matress the use of a device such as the
kendrick extraction device (KED) is one to be considered in patients such
as this. It provides almoast complete immobilisation from the neck to the
torso. (1) This allows the patient to be sat up at a 30-40 degree angle to
allow for best ventilation.(2) This same method can be used with patients
with facial injuries with risk of airway compromise due to heamorhage.
1. Castellano, J. (2007). Prehospital management of spinal cord
injuries. Emergencies. 19 (1), 25-31.
2. Blair . (1955). The effect of change in body position on lung
volume and intrapulmonary gas mixing in normal subjects. Journal Clinical
investigation.
We read this intriguing case report with great interest. However, it contained two specific weaknesses which undermined its strength, leaving it inconclusive. The critical point is not whether caffeine excess might cause seizures (this is known), or the theoretical pathophysiology (comprehensively discussed in the article), but whether it was the definitive cause of seizures in this case.
Firstly, without meas...
Thank you for taking the time to read and respond to our paper and for usefully highlighting the possible application of the Kendrick Extrication Device (KED) in such circumstances.
We can confirm that had nebulisation been required prior to extrication from the premises that the application of the KED would have been considered. In our case however the initial position of the patient enabled a simple rearwar...
Thank you for taking the time to read and respond to our paper. The authors are very grateful for your information on the 'Aero Neb Go Mask'. The Scottish Ambulance Service (SAS) currently use the Lifecare micro neb III)which does not enable nebulisation in the supine position. Having viewed the Aero Neb Go Mask it would appear that it would have been effective in our case. The authors would be interested to know whethe...
We thank Dr. Lopez and colleagues for this large prospective study evaluating the benefit of a triage flowchart to rule out acute coronary syndrome (ACS) in the emergency department1. They apply a 5 steps flowchart to classify patients as "triage non-ACS": i.e. patients less than 40 years old, absence of diabetes, no previously known coronary artery disease, non-oppressive and non-retrosternal pain. In their sample of 4...
We were concerned to read the paper by Figgan et al (1) demonstrating the ambulance clinicians lack of compliance with prehospital guidance during assessment of chest pain presentations. Chauhan et al (2) also appropriately highlight the need for accurate assessment of posterior myocardial infarction (PMI) and that this particular presentation of Acute Coronary Syndrome (ACS) appears to have received little attention in p...
Thankyou for your informative article investigating the use of ketamine in prehospital intubation.
From your article it seems clear that data was collected identifying who undertook the intubations in each case; I was wondering if there was any significant difference in success rates, number of attempts and complication rates between paramedic and physician intubations?
If this data is available I'm...
In their informative article, Fitzpatrick, Brady and Maguire (1) demonstrate an excellent method for delivering nebulised medication to a supine patient. The authors also state they are unaware of any commercially available devices able to nebulise a supine patient. Although I have no personal experience with the mask in question, the Aero Neb Go mask, produced by Romsons International, utilizes an elbow adapter, allowing neb...
Dear Editor
I would be very grateful if the author of this clinical image could be given the opportunity to describe the clinical aspects of the case.
Pelvic splints are applied in the pre-hospital environment for suspected pelvic fractures and should be removed by the emergency department when imaging has excluded an unstable fracture pattern and when the patient is haemodynamically stable.
...
Although the gold standard of immobilisation is in a prone position, with a C collar and a vaccum matress the use of a device such as the kendrick extraction device (KED) is one to be considered in patients such as this. It provides almoast complete immobilisation from the neck to the torso. (1) This allows the patient to be sat up at a 30-40 degree angle to allow for best ventilation.(2) This same method can be used with...
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