Blood pressure target in septic shock

April 1, 2014 by  
Filed under Acute Med, All Updates, ICU, Resus

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ABP-iconA study comparing mean arterial pressure (MAP) targets of 80 to 85 mm Hg (high-target group) with 65 to 70 mm Hg (low-target group) n 776 septic shock patients – the SEPSISPAM study – did not show a difference in the primary endpoint of 28 day mortality. Among patients with chronic hypertension, those in the high-target group required less renal-replacement therapy than did those in the low-target group. In my view this supports an approach that targets MAP based on the individual patient’s history rather than a blanket one-number-fits-all approach. The MAPs actually achieved in the low-target group were between 70-75 mm of Hg.

For a more thorough review check out the great PulmCCM blog.

High versus Low Blood-Pressure Target in Patients with Septic Shock.
N Engl J Med. 2014 Mar 18. [Epub ahead of print] Free Full Text


Background: The Surviving Sepsis Campaign recommends targeting a mean arterial pressure of at least 65 mm Hg during initial resuscitation of patients with septic shock. However, whether this blood-pressure target is more or less effective than a higher target is unknown.

Methods: In 31 emergency departments in the United States, we randomly assigned patients with septic shock to one of three groups for 6 hours of resuscitation: protocol-based EGDT; protocol-based standard therapy that did not require the placement of a central venous catheter, administration of inotropes, or blood transfusions; or usual care. The primary end point was 60-day in-hospital mortality. We tested sequentially whether protocol-based care (EGDT and standard-therapy groups combined) was superior to usual care and whether protocol-based EGDT was superior to protocol-based standard therapy. Secondary outcomes included longer-term mortality and the need for organ support.

Results: At 28 days, there was no significant between-group difference in mortality, with deaths reported in 142 of 388 patients in the high-target group (36.6%) and 132 of 388 patients in the low-target group (34.0%) (hazard ratio in the high-target group, 1.07; 95% confidence interval [CI], 0.84 to 1.38; P=0.57). There was also no significant difference in mortality at 90 days, with 170 deaths (43.8%) and 164 deaths (42.3%), respectively (hazard ratio, 1.04; 95% CI, 0.83 to 1.30; P=0.74). The occurrence of serious adverse events did not differ significantly between the two groups (74 events [19.1%] and 69 events [17.8%], respectively; P=0.64). However, the incidence of newly diagnosed atrial fibrillation was higher in the high-target group than in the low-target group. Among patients with chronic hypertension, those in the high-target group required less renal-replacement therapy than did those in the low-target group, but such therapy was not associated with a difference in mortality.

Conclusions: Targeting a mean arterial pressure of 80 to 85 mm Hg, as compared with 65 to 70 mm Hg, in patients with septic shock undergoing resuscitation did not result in significant differences in mortality at either 28 or 90 days.

No Benefit From Early Goal Directed Therapy

March 19, 2014 by  
Filed under Acute Med, All Updates, Guidelines, ICU, Resus

The first of three major trials assessing early goal directed therapy (EGDT) in sepsis – the American ProCESS Trial – has been published.

It showed what many of us thought – that the specific monitoring via a central line of central venous oxygen saturation – was not necessary for improved survival.

However the trial randomised 1341 patients to one of three arms:
(1) protocolised EGDT
(2) protocol-based standard therapy that did not require the placement of a central venous catheter, administration of inotropes, or blood transfusions
(3) ‘usual care’ which was not standardised.

There were no differences in any of the primary or secondary outcomes between the groups.

Interestingly, in the six hours of early care that the trial dictated, the volume of intravenous fluids administered differed significantly among the groups (2.8 litres in the protocol-based EGDT group, 3.3 litres in the protocol-based standard-therapy group, and 2.3 litres in the usual-care group).

There was also a difference in the amount of vasopressor given, with more patients in the two protocol-based groups receiving vasopressors (54.9% in the protocol-based EGDT group, 52.2% in the protocol-based standard-therapy group, 44.1% in the usual-care group).

The use of intravenous fluids, vasopressors, dobutamine, and blood transfusions between 6 and 72 hours did not differ significantly among the groups.

Overall 60 day mortality was in the region of 20% for all groups.

What are the take home points here? Firstly, overall sepsis outcomes have improved over recent years, and early recognition and antibiotic administration may be the most important components of care. In the early emergency department phase of care, protocolised fluid and vasopressor therapy may not be as important as we thought. Good clinical assessment and regular review seem to be as effective and perhaps more important than any specific monitoring modality or oxygen delivery-targeted drug and blood therapy.

We all await the ARISE and ProMISE studies which may shed more light on the most important components of early sepsis care.

A Randomized Trial of Protocol-Based Care for Early Septic Shock
NEJM Mar 18 2014 (Full Text Link)


Background: In a single-center study published more than a decade ago involving patients presenting to the emergency department with severe sepsis and septic shock, mortality was markedly lower among those who were treated according to a 6-hour protocol of early goal-directed therapy (EGDT), in which intravenous fluids, vasopressors, inotropes, and blood transfusions were adjusted to reach central hemodynamic targets, than among those receiving usual care. We conducted a trial to determine whether these findings were generalizable and whether all aspects of the protocol were necessary.

Methods: In 31 emergency departments in the United States, we randomly assigned patients with septic shock to one of three groups for 6 hours of resuscitation: protocol-based EGDT; protocol-based standard therapy that did not require the placement of a central venous catheter, administration of inotropes, or blood transfusions; or usual care. The primary end point was 60-day in-hospital mortality. We tested sequentially whether protocol-based care (EGDT and standard-therapy groups combined) was superior to usual care and whether protocol-based EGDT was superior to protocol-based standard therapy. Secondary outcomes included longer-term mortality and the need for organ support.

Results: We enrolled 1341 patients, of whom 439 were randomly assigned to protocol-based EGDT, 446 to protocol-based standard therapy, and 456 to usual care. Resuscitation strategies differed significantly with respect to the monitoring of central venous pressure and oxygen and the use of intravenous fluids, vasopressors, inotropes, and blood transfusions. By 60 days, there were 92 deaths in the protocol-based EGDT group (21.0%), 81 in the protocol-based standard-therapy group (18.2%), and 86 in the usual-care group (18.9%) (relative risk with protocol-based therapy vs. usual care, 1.04; 95% confidence interval [CI], 0.82 to 1.31; P=0.83; relative risk with protocol-based EGDT vs. protocol-based standard therapy, 1.15; 95% CI, 0.88 to 1.51; P=0.31). There were no significant differences in 90-day mortality, 1-year mortality, or the need for organ support.

Conclusions: In a multicenter trial conducted in the tertiary care setting, protocol-based resuscitation of patients in whom septic shock was diagnosed in the emergency department did not improve outcomes

Use a table for selecting PEEP in ARDS

March 13, 2014 by  
Filed under Acute Med, All Updates, ICU, Resus

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PEEPtable.001Selecting the right amount of PEEP to recruit collapsed alveoli in patients with ARDS is important but the best method isn’t proven. Using a table to select PEEP based on FiO2 was significantly but weakly associated with improved lung recruitability (on CT scan) when compare with other methods of selecting PEEP, and was the best method for avoiding higher PEEP in patients with lower recruitability.

This is a small study and the results do not necessarily translate to improved clinical outcomes, but they may be of interest to emergency and retrieval medicine physicians who require a simple and safe strategy when managing ARDS patients without the luxury of time or of access to highly sophisticated ICU ventilators.

Bedside selection of positive end-expiratory pressure in mild, moderate, and severe acute respiratory distress syndrome
Crit Care Med. 2014 Feb;42(2):252-64


OBJECTIVE: Positive end-expiratory pressure exerts its effects keeping open at end-expiration previously collapsed areas of the lung; consequently, higher positive end-expiratory pressure should be limited to patients with high recruitability. We aimed to determine which bedside method would provide positive end-expiratory pressure better related to lung recruitability.

DESIGN: Prospective study performed between 2008 and 2011.
SETTING: Two university hospitals (Italy and Germany).

PATIENTS: Fifty-one patients with acute respiratory distress syndrome.

INTERVENTIONS: Whole lung CT scans were taken in static conditions at 5 and 45 cm H2O during an end-expiratory/end-inspiratory pause to measure lung recruitability. To select individual positive end-expiratory pressure, we applied bedside methods based on lung mechanics (ExPress, stress index), esophageal pressure, and oxygenation (higher positive end-expiratory pressure table of lung open ventilation study).

MEASUREMENTS AND MAIN RESULTS: Patients were classified in mild, moderate and severe acute respiratory distress syndrome. Positive end-expiratory pressure levels selected by the ExPress, stress index, and absolute esophageal pressures methods were unrelated with lung recruitability, whereas positive end-expiratory pressure levels selected by the lung open ventilation method showed a weak relationship with lung recruitability (r = 0.29; p < 0.0001). When patients were classified according to the acute respiratory distress syndrome Berlin definition, the lung open ventilation method was the only one which gave lower positive end-expiratory pressure levels in mild and moderate acute respiratory distress syndrome compared with severe acute respiratory distress syndrome (8 ± 2 and 11 ± 3 cm H2O vs 15 ± 3 cm H2O; p < 0.05), whereas ExPress, stress index, and esophageal pressure methods gave similar positive end-expiratory pressure values in mild, moderate, and severe acute respiratory distress syndrome. The positive end-expiratory pressure selected by the different methods were unrelated to each other with the exception of the two methods based on lung mechanics (ExPress and stress index).

CONCLUSIONS: Bedside positive end-expiratory pressure selection methods based on lung mechanics or absolute esophageal pressures provide positive end-expiratory pressure levels unrelated to lung recruitability and similar in mild, moderate, and severe acute respiratory distress syndrome, whereas the oxygenation-based method provided positive end-expiratory pressure levels related with lung recruitability progressively increasing from mild to moderate and severe acute respiratory distress syndrome.

The ‘Magic Eye®’ method of rhythm assessment

February 9, 2014 by  
Filed under Acute Med, All Updates, EMS, ICU, Resus

Are you someone who tries to determine whether an ECG trace is ‘irregularly irregular’ by drawing little dots on a piece of paper level with the R waves to see if they are evenly spaced? I’d done that for years until I read this fantastic suggestion, which I’ve been following for over a year now.

In the 1990s there was a popular series of posters and books called ‘Magic Eye‘. These contained a ‘random dot autostereogram‘ which appeared as a mish-mash of coloured dots, but when you stared at it for a while the illusion of a 3D image would emerge. They looked a bit like this (although this one won’t work at such reduced resolution):

Image Credit: Wikimedia Commons

Image Credit: Wikimedia Commons

Dr Broughton and colleagues from Cambridge, UK, discovered that this technique, which involves forcing a divergent gaze to get repeating patterns to appear to overlap, can be applied to an ECG trace.

Stereoviewing an ECG trace causes successive QRS complexes to visually overlap and produce a new image. As Broughton and colleagues point out:

When achieved, this will lead to one of three outcomes. Entirely regular rhythms will ‘click’ into place as a new image at fixed depth. Rhythms with only mild irregularity may be stereoviewable, and if so, will appear to show successive QRS complexes at subtly varying depths. Rhythms with marked irregularity will not be stereoviewable, instead (in our experience) merely giving the viewer sore eyes after several failed viewing attempts.”

The authors assert that this can be applied to continuous ECG monitors, although unless you are really good at stereoviewing while moving your head/eyes horizontally, you should really freeze the trace on the screen first.

The ‘Magic Eye®’ method of rhythm assessment
Anaesthesia. 2012 Oct;67(10):1170-1

Not finding a difference doesn’t prove equivalence

January 28, 2014 by  
Filed under Acute Med, All Updates, EMS, Resus

Image from http://www.physio-control.com/

The recent LINC trial was a randomised controlled trial comparing a mechanical chest compression device (LUCAS) with manual CPR(1). “No significant difference” was found for any of the main outcome measures considered.

So do you think the LINC trial demonstrated that mechanical CPR using the LUCAS device is equivalent, or at least not inferior, to manual CPR?

This was an interesting and important trial for those of us who manage prehospital cardiac arrest patients. In some social media discussions, it appears to have been interpreted by some as evidence that they are equivalent resuscitative techniques or that LUCAS is not inferior to manual CPR.

LINCdata

However, unless you see a p-value less than 0.05 in the table above, (issues of multiple hypotheses testing aside) no evidence of anything was demonstrated; not of difference and certainly not of equivalence. When faced with 2-sided p values >5%, investigators often conclude that there is “no difference” between the treatments, leading to an assumption among readers that the treatments are equivalent. A better conclusion is that there is “no evidence” of a difference between treatments (see opinion piece by Sackett, 2004(2)). In order to determine if treatments are equivalent, equivalence must be tested directly.

How can we test for equivalence?
First, we must define equivalence. It is crucial that this definition is provided a priori i.e. defined before the data are examined. As the focus of the LINC study was on superiority the investigators did not offer an a priori definition of equivalence. However, the CIRC study(3), conducted some time earlier and similar in design, did. (This study examined an alternative mechanical CPR device, the Zoll AutoPulse).

When establishing equivalence between treatments, instead of the more customary null hypothesis of no difference between treatments, the hypothesis that the true difference is equal to a specified ‘delta’ (δ) is tested (4).

To analyse the LINC results to look for equivalence, we can derive our delta values from the CIRC study, which as we’ve said did offer an a priori definition of equivalence. For the purpose of illustration, we will use the risk-difference stopping boundaries calculated for the CIRC study, rather than the odds ratio based equivalence margins, on the grounds of greater simplicity and clinical appropriateness. Therefore, we set our equivalence margins at -δ=-1.4% and δ=1.6%, meaning, where LUCAS fared no worse than manual CPR by 1.4% and no better by 1.6%, we will consider the two techniques equally efficacious. Thus, we will declare equivalence between LUCAS and manual CPR if the 2-sided 95% CI for the treatment difference lies entirely within -1.4% and 1.6%, and noninferiority if the one-sided 97.5% CI for the treatment difference (equivalent to the lower limit of the two-sided 95% CI) lies above -1.4%. (5).

These concepts and how they differ from a traditional comparison are more readily appreciated graphically (Fig. 1).

Figure 1. Two one-sided test procedure and the equivalence margin in equivalence/noninferiority testing between LUCAS and manual CPR

1a Traditional comparative study, such as the LINC trial, shows results with confidence intervals that show no evidence of a difference as they encompass 0.

LINCtradcomp

1b. Using equivalence margins (-δ and δ) derived from a similar study (CIRC), we show that the LINC trial does not demonstrate that LUCAS and manual CPR are equally efficacious, since the 95% CI do not lie completely within the equivalence margins.

LINCequiv
1c. The one sided CI lies above -δ for some outcomes, allowing us to declare non-inferiority on those measures.
LINCnoninf

Conclusion
The presentation of the LINC trial’s results shows no evidence of a difference in outcomes between mechanical and manual CPR, which is not the same as showing they are equivalent or that mechanical CPR is non-inferior. However if we re-examine their data using equivalence margins (-δ, δ) derived from a similar study (CIRC), there is some evidence that the LUCAS device is not inferior to manual CPR (but not necessarily equivalent) with respect to longer term good neurological outcome.

References

1. Rubertsson S, Lindgren E, Smekal D, er al. Mechanical Chest Compressions and Simultaneous Defibrillation vs Conventional Cardiopulmonary Resuscitation in Out-of-Hospital Cardiac Arrest
JAMA. 2014 Jan 1;311(1):53-61

2. Sackett D. Superiority trials, non-inferiority trials, and prisoners of the 2-sided null hypothesis
Evid Based Med 2004;9:38-39 [Open Access]

3. Lerner EB, Persse D, Souders CM, et al. Design of the Circulation Improving Resuscitation Care (CIRC) Trial: a new state of the art design for out-of-hospital cardiac arrest research
Resuscitation. 2011 Mar;82(3):294-9

4. Dunnett CW, Gent M. Significance testing to establish equivalence between treatments, with special reference to data in the form of 2X2 tables. Biometrics. 1977 Dec;33(4):593-602

5. Piaggio G, Elbourne DR, Pocock SJ, et al. Reporting of noninferiority and equivalence randomized trials: extension of the CONSORT 2010 statement. JAMA. 2012;308(24):2594-604. [Open Access]

Does RV enlargement on echo predict PE?

January 20, 2014 by  
Filed under Acute Med, All Updates, ICU, Resus, Ultrasound

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A nice paper from Annals of Emergency Medicine showing the test characteristcs of some of the common signs we look for on basic 2D echo that suggest the presence of (sub)massive pulmonary embolism:

Right Ventricular Dilatation on Bedside Echocardiography Performed by Emergency Physicians Aids in the Diagnosis of Pulmonary Embolism
Ann Emerg Med. 2014 Jan;63(1):16-24


STUDY OBJECTIVE: The objective of this study was to determine the diagnostic performance of right ventricular dilatation identified by emergency physicians on bedside echocardiography in patients with a suspected or confirmed pulmonary embolism. The secondary objective included an exploratory analysis of the predictive value of a subgroup of findings associated with advanced right ventricular dysfunction (right ventricular hypokinesis, paradoxical septal motion, McConnell’s sign).

METHODS: This was a prospective observational study using a convenience sample of patients with suspected (moderate to high pretest probability) or confirmed pulmonary embolism. Participants had bedside echocardiography evaluating for right ventricular dilatation (defined as right ventricular to left ventricular ratio greater than 1:1) and right ventricular dysfunction (right ventricular hypokinesis, paradoxical septal motion, or McConnell’s sign). The patient’s medical records were reviewed for the final reading on all imaging, disposition, hospital length of stay, 30-day inhospital mortality, and discharge diagnosis.

RESULTS: Thirty of 146 patients had a pulmonary embolism. Right ventricular dilatation on echocardiography had a sensitivity of 50% (95% confidence interval [CI] 32% to 68%), a specificity of 98% (95% CI 95% to 100%), a positive predictive value of 88% (95% CI 66% to 100%), and a negative predictive value of 88% (95% CI 83% to 94%). Positive and negative likelihood ratios were determined to be 29 (95% CI 6.1% to 64%) and 0.51 (95% CI 0.4% to 0.7%), respectively. Ten of 11 patients with right ventricular hypokinesis had a pulmonary embolism. All 6 patients with McConnell’s sign and all 8 patients with paradoxical septal motion had a diagnosis of pulmonary embolism. There was a 96% observed agreement between coinvestigators and principal investigator interpretation of images obtained and recorded.

CONCLUSION: Right ventricular dilatation and right ventricular dysfunction identified on emergency physician performed echocardiography were found to be highly specific for pulmonary embolism but had poor sensitivity. Bedside echocardiography is a useful tool that can be incorporated into the algorithm of patients with a moderate to high pretest probability of pulmonary embolism.

Sepsis research – let’s get some answers

December 17, 2013 by  
Filed under Acute Med, All Updates, ICU, Resus

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There’s so much debate on which components of Early Goal Directed Therapy in sepsis really make a difference. The good news is that three randomised controlled trials in the UK, Australasia, and North America, aim to answer the question, and the study design from the outset has been a collaboration that will allow the results to be pooled.

ProMISe is taking place in the UK, ProCESS in the US, and ARISE in Australasia.

sepsistrialssm

The Australasian study (ARISE) and is nearing completion. If you can recruit patients then please do. Listen to a podcast on this fantastic study with lead investigator Dr Anthony Delaney.

London Trauma Conference Day 3

December 13, 2013 by  
Filed under Acute Med, All Updates, EMS, ICU, Resus, Trauma


Dr Louisa Chan reports on Day 3 of the London Trauma Conference

There was a jam-packed line up for the Pre-hospital and Air Ambulance Day which was Co-hosted by the Norwegian Air Ambulance Foundation.
 

My highlights were:

HEMS

Dr Rasmus Hesselfeldt works in Denmark where they have a pretty good EMS system with ambulances, RRV’s and PHC doctors. Road conditions are good with the longest travel distance of 114 miles. So would the introduction of a HEMS service improve outcomes? He did an observational study looking at year of data post-trial and compared this with 5 months pre-trial. Trauma patients with ISS > 15 and medical emergencies greater than 30 min by road to the Trauma Centre (TC). Primary endpoint was time to TC, secondary outcomes were number of secondary transfers and 30 day mortality.

Results: Increase in on scene time 20 min vs 28 min, time to hospital increased but time to TC was less – 218 min vs 90 min, reduced mortality, increased direct transfer to TC and fewer secondary transfers.

Full article here: A helicopter emergency medical service may allow faster access to highly specialised care. Dan Med J. 2013 Jul;60(7):A4647

 

Airway

Prof Dan Davis ran through pre-hospital intubation. It seems that this man has spent his life trying to perfect airway management. Peter Rosen was his mentor and imprinted on him that RSI is the cornerstone of airway management.

So surely pre-hospital intubation saves lives. The evidence however begs to differ, or does it? As with all evidence we need to consider the validity of the results and luckily Prof Davis has spent a lot of time thinking through the reasons why there no evidence.

During his research he opened a huge can of worms:
1. Hyperventilation was common – any EtCO2 <30mmHg lead to a doubling in mortality.
2. First pass intubation is great, but not if you let your patient become hypoxic or hypotension or worse still both!
3. Hospital practice had similar issues.

So really the RSI processes he was looking at weren’t great.

The good news is that things have improved and he can now boast higher first pass rates and lower complication rates for his EMS system. His puts this success down to training.

 

 

AIRPORT-LTCThe AIRPORT study was discussed at last years LTC. This year we have the results. 21 HEMS services in 6 countries were involved in the data collection including GSA HEMS. The headline findings are that intubation success rates are high (98%) with a complication rate of 10-12%. The more difficult airways were seen in the non-trauma group. 28.2% patients died (mainly cardiac arrest).

 

 

Matt Thomas reported on REVIVE – a pre-hospital feasibility study looking at airway management in OHCA (I-Gel vs LMA Supreme vs standard care). It was never powered to show a difference in these groups, the main aim was to see if research in this very challenging area was possible. And the answer is YES. The paramedics involved recruited more patients than expected and stuck to the protocol (prob better that docs would have!). A randomised controlled trial to look at the I-Gel vs ETT is planned.

 

(P)REBOA

ReboaLTCFinally, Pre-hospital Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) seems eminently possible – Dr Nils Petter Oveland showed us the training manikin they developed for training. Through training on this manikin they achieved an average skin to balloon time of 3.3mins. Animal data supports this procedure as a bridge to definitive care in non compressible haemorrhage.

London HEMS will be starting (P)REBOA in the New Year.

So now it’s stand up science, I’m off for my glass of wine…………….

Check out what they’re saying about the London Trauma Conference on Twitter

London Trauma Conference Day 2

December 12, 2013 by  
Filed under Acute Med, All Updates, EMS, ICU, Resus, Trauma

London Trauma Conference 2013 – Day 2  by Dr Louisa Chan

So I find myself torn today: do I join the the main track with a Major incident theme or the Cardiac Masterclass? I never liked the thought of missing out on anything so I went to a bit of both.

 
Cardiac Masterclass

A lot of people probably think that managing cardiac arrest isn’t challenging and a bit dull because the patient is dead. But the Cardiac Masterclass would inspire you to think of a bright future for cardiac arrest management.

Mark Whitbread reminded us of how important dispatch is in the chain of survival. How much focus do we put on improving bystander CPR rates? Dispatcher assisted CPR has been shown to improve outcomes and needs to be skilfully done.

Ajay Jain pushes for all OHCA patients to be taken to a Cardiac Arrest centre for PCI. Why? Because the results he has from his centre for PCI in OHCA patients results in 77% (101/132) patients surviving to hosp discharge, 65% neurologically intact.

He also tells us that the ECG post arrest is a very poor predictor of PCI findings (although STEMI predicts a positive result) so they all should have PCI.
Lyon-survivors

 

More data from TOPCAT shows us that non survivors of OHCA are easy to cool.

 

LTC-mice

 

 

And maybe we should be cooling DURING cardiac arrest to minimise the reperfusion injury.

 

 

For persistent VF Prof Redwood says revascularisation is the key; when that doesn’t work then reducing LV volume may help so aspiration or an Impella may work. Failing that – ECMO.

 
Major Incidents

Major Incidents by their nature do not happen every day, so experience in these incidents is limited. The challenge then is how can we learn from incidents?

A standardised reporting system for a major incident database would be a good idea – www.majorincidentreporting.org – is where you will find the standard report form and open access database.

And then all I can suggest is that you need to come to the LTC and listen to the accounts of those who have been there. We heard about the Tokyo Sarin attack, Mumbai, and a very compelling story of multiple drownings from Steen Barnung.

Lessons from Tokyo – Sarin attack:

It will happen again
It will be chaos
Crowds cannot be controlled
Comms will fail
Clinical diagnosis – need a senior clinician
Treatment must be immediately available – 3min to absorb sarin
Decontamination – get naked, 90% decon with clothes removal.
Stream casualties
Empower the man on the ground.

 

Gadgets

LTC-MSUThe great thing about the London Trauma Conference is that it’s not just about the content of the tracks, there’s the networking and the opportunity to see new pieces of equipment.

The Norwegians won on the equipment front with their Mobile Stroke Unit. It’s due to go on line in 2014.

So TTFN and more from me on Day 3 of #LTC2013

London Trauma Conference 2013

December 11, 2013 by  
Filed under Acute Med, All Updates, EMS, ICU, Resus, Trauma

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FDIA_ImageOur inside reporter Dr Louisa Chan provides an update from Day One of the London Trauma Conference:

At risk of sounding like a resuscisaurus, last year was my first foray into the world of blogging. I’m proud to say that the genetic make up of most emergency physicians allows us to adapt so that others do not die! And so here I am again, making my way into the big smoke to report on the great developments of 2013.

I’ve struggled in the past to prise myself away from the main trauma track, it is after all the London Trauma Conference, which has left me curious as to the content of the Cardiac arrest symposium, this year it has been integrated, so I finally get to scratch that itch.

 

Prehospital Cardiac Arrest Management in Scotland

The conference was kicked off by Richard Lyon‘s inspirational description of his TOPCAT study.

In Scotland, of 50 cardiac arrests, 6 will survive to hospital and only 1 will survive to hospital discharge. The survival to hospital discharge in the UK is getting worse (4.8% 1995- 0.7% 2007)

Spurred on by these dreadful figures and a personal quest to improve cardiac arrest care (his father succumbed to a cardiac arrest in his forties)

All in all he has studied 400 cardiac arrest patients pre hospital. So what has he learnt?

  • Precise application of the chain of survival to your own system is vital in the delivery of Quality CPR.
  • He started in the ambulance control room analysing calls (CPR starts at step 11 so more experienced dispatchers skip thee quicker) and worked his way through the chain of survival.
  • The TOPCAT study revealed a 3 min delay to compressions where early intubation and cannulation were performed. Through an education program delivering knowledge and skills with individualised feedback they were able to increase on-chest time.
  • LEADERSHIP was a big factor. Having a clinician dedicated to managing the team improved on chest time and is now delivered by paramedics manning a car response in Edinburgh.
  • Breaks in CPR during movement are overcome by a mechanical chest compression device on carry sheet.
  • Non technical skills are monitored by camera feed
  • These changes have led to a survival to hospital discharge rate of 38% for patients in VF
  • This could translate into an extra 300 lives saved in Scotland when these changes are rolled out nationally.
  • And now there is a move to transport patients who are in VF after the third shock then straight to cath lab.

 

Echocardiography in cardiac arrest

Prof Tim Harris spoke about his passion – echocardiography in resuscitation. If you were in any doubt before then you would leave convinced.

Of course echo should not interfere with CPR so it should be done during the rhythm check with a 10 sec count down.

He covered the usual uses; PEA vs EMD in prognostication (92% sensitivity and 82% specificity to ROSC), Circulation assessment and an estimation of EF (Normal function – anterior mitral valve leaflet hits the septum or is within 5mm , EF 30-45% between 5mm- 18mm and >18mm ant mitral valve leaflets – 30% EF)

 

Cardiogenic shock after cardiac arrest

Professor Deakin: optimising cardiac function after ROSC revolves around the three elements of preload, SVR and myocardial contractility. For those who can still remember how, he recommends preload should be optimised to a LA pressure 15-20mmHg (2-12 normal) with a Swan Ganz catheter.
SVR and contractility can be manipulated thereafter using traditional vasopressors and inotropes or more novel agents like Levosimendan.
Mechanical devices such as IABP, Impella, TandemSupport are useful if available.
Where does the future lie? Perhaps synchronised pacing, hypothermia, extrathoracic ventilation and gene therapy.

LTC-BrohiOpen chest cardiac massage

Prof Karim Brohi: external chest compressions have been around since the 1960′s. Without a doubt external compressions generate a cardiac output, but is this the best way?
Over the last 10 years the priorities in traumatic cardiac arrest have changed – chest compressions are not instituted until after reversible causes have been addressed.
In non traumatic arrest how could we improve?
In canine models coronary perfusion pressure is five times better with internal cardiac massage, providing better survival rates with intact neurology.
There are a few human studies showing marked differences in cardiac index: 1.31 in the open group vs 0.61 in the closed group. In a Japanese study (1993), ROSC was achieved in 58% in open vs 1% closed.
The technique is two handed and the same as that taught in thoracotomy training. The difference is that in medical cardiac arrest you can use a smaller incision ( left lateral).
Who should we use open cardiac massage on? Perhaps in tamponade and pulmonary embolism?

How about when? When 10-15min with “standard care” has failed?

Perhaps it is time for a trial?

Post cardiac arrest syndrome and neuro protective measures
Prof Simon Redwood and Matt Thomas had overlapping talks on this . The bottom line is don’t have too much or too little CO2 or O2. The therapeutic hypothermia debate continues, what is evident is that there should be temperature control to avoid hyperthermia but what temperature? And there may be other benefits to hypothermia eg. limitation of infarct size.

What has been evident from all the speakers today is that it is an integrated system that saves lives and in order to guide the development of your system you need data and the belief that you can improve cardiac arrest outcomes.

More from me tomorrow!

Louisa Chan

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