Extracorporeal cardiopulmonary resuscitation (E-CPR) using extracorporeal membrane oxygenation (ECMO) support during inhospital cardiac arrest has been attempted to improve the outcome of cardiopulmonary resuscitation (CPR). A retrospective, single-center, observational study from Korea analysed a total of 406 adult patients with witnessed inhospital cardiac arrest receiving cardiopulmonary resuscitation for >10 mins.
How their system works: An ECMO cart was transported to the CPR site within 5–10 mins during the day and within 10–20 mins during the night shift. The decision to use E-CPR was dependent on the CPR team leader. Application of ECMO was usually considered under conditions of prolonged arrest (when there was no ROSC after 10–20 mins of CPR), recurrent arrest (when ROSC could not be maintained), or when the patient could not be expected to recover as a result of underlying severe left ventricular dysfunction or coronary artery disease despite a short CPR duration (end-stage heart failure requiring transplantation, left main coronary artery occlusion, etc)
The primary end point was a survival discharge with minimal neurologic impairment.
85 patients underwent E-CPR and 321 underwent C- CPR. ECMO implantation was successful in 94.1% (80 of 85) in the E-CPR group, except for three cannulation failures and two ECMO flow failures. There was a signficantly greater proportion of patients with primary cardiac disease in the E-CPR group. Propensity score matching was used to balance the baseline characteristics and cardiopulmonary resuscitation variables that could potentially affect prognosis. In the matched population (n = 120), the survival discharge rate with minimal neurologic impairment in the extracorporeal cardiopulmonary resuscitation group was significantly higher than that in the conventional cardiopulmonary resuscitation group (odds ratio of mortality or significant neurologic deficit, 0.17; 95% confidence interval, 0.04-0.68; p = .012). In addition, there was a significant difference in the 6-month survival rates with minimal neurologic impairment (hazard ratio, 0.48; 95% confidence interval, 0.29-0.77; p = .003; p <.001 by stratified log-rank test). In the subgroup based on cardiac origin, extracorporeal cardiopulmonary resuscitation also showed benefits for survival discharge (odds ratio, 0.19; 95% confidence interval, 0.04-0.82; p = .026) and 6-month survival with minimal neurologic impairment (hazard ratio, 0.56; 95% confidence interval, 0.33-0.97; p = .038; p = .013 by stratified log-rank test).
The authors conclude that extracorporeal cardiopulmonary resuscitation showed a survival benefit over conventional cardiopulmonary resuscitation in patients who received cardiopulmonary resuscitation for >10 mins after witnessed inhospital arrest, especially in cases of cardiac origin. These results contrast with these recently published French findings in patients receiving ECMO after out-of-hospital cardiac arrest.
Extracorporeal cardiopulmonary resuscitation in patients with inhospital cardiac arrest: A comparison with conventional cardiopulmonary resuscitation
Crit Care Med. 2011 Jan;39(1):1-7
Category Archives: All Updates
Better outcomes with conventional CPR
A very large nationwide Japanese observational study examined outcomes in out-of-hospital cardiac arrest patients who received CPR from lay rescuers. They compared conventional CPR (with mouth-to-mouth and chest compressions) with compression-only CPR. Over 40 000 patients were included.
Conventional CPR was associated with better outcomes than chest compression only CPR, for both one month survival (adjusted odds ratio 1.17, 95% confidence interval 1.06 to 1.29) and neurologically favourable one month survival (1.17, 1.01 to 1.35). Neurologically favourable one month survival decreased with increasing age and with delays of up to 10 minutes in starting CPR for both conventional and chest compression only CPR. The benefit of conventional CPR over chest compression only CPR was significantly greater in younger people in non-cardiac cases (P=0.025) and with a delay in start of CPR after the event was witnessed in non-cardiac cases (P=0.015) and all cases combined (P=0.037).
The authors conclude that conventional CPR is associated with better outcomes than chest compression only CPR for selected patients with out of hospital cardiopulmonary arrest, such as those with arrests of non-cardiac origin and younger people, and people in whom there was delay in the start of CPR.
Outcomes of chest compression only CPR versus conventional CPR conducted by lay people in patients with out of hospital cardiopulmonary arrest witnessed by bystanders: nationwide population based observational study
BMJ 2011; 2011; 342:c7106 Full Text
Cervical spine guideline
The UK College of Emergency Medicine has produced guidelines on the management of cervical spine injury in the ED
Since I have a bit of a ‘thing’ about the obsession with cervical immobilisation, I’m reproducing here an excerpt from the guideline regarding this topic:
In 1998, Hauswald published retrospective data that compared the neurological outcomes of 334 patients with blunt traumatic cervical spinal injury who all had spinal immobilisation performed (New Mexico) with 120 patients with blunt traumatic cervical spinal injury that had no spinal immobilisation performed (Malaya). There was a non-significant increase in neurological disability in the immobilised group. Though this comparison is flawed, the author’s argument that any cord injury from blunt trauma occurs at the time of the impact, that subsequent movement is very unlikely to cause further damage, and that alert patient will develop a position of comfort with muscle spasm protecting the spine appears credible. It is widely accepted that it may be harmful for patients with pre-existing vertebral anatomical abnormalities eg ankylosing spondylitis to have their neck forced into an unnatural position and such patients usually have their neck supported in a position of comfort with or without a collar.
A Cochrane review updated in 2009 by Kwan et al concluded that in the absence of any randomised controlled trials the low incidence of unstable injuries of the cervical spine amongst those immobilised raised the possibility that immobilisation may be associated with a higher morbidity and mortality than non-immobilisation. In a recent literature review, Benger and Blackman concluded that alert, co-operative trauma patients do not require cervical spine immobilisation unless their conscious level deteriorates or they find short-term support of a collar helpful.
The evidence both for and against cervical spine immobilisation is weak. Although Hauswald’s study is intriguing, if we accept a 1-2% prevalence of unstable cervical spine injury following blunt trauma and hypothesise that 1 in 10 patients with unstable cervical spinal injuries would suffer a spinal cord injury as a consequence of non-immobilisation of their neck then only 1 in 500 -1,000 patients would be harmed as a result, which exceeds Hauswald’s study population. There is a need for large randomised multi-centre trials to determine the risk:benefit ratio of neck immobilisation. However, the current practice of cervical spine immobilisation has been so widely adopted and the consequence of causing or exacerbating a spinal injury so catastrophic that such trials may not be supported by ethical committees….Though evidence that the use of cervical collars prevents secondary injury is lacking, no evidence could be found to contradict this statement and it is, therefore, supported.
The guideline does not specify what exactly they mean by cervical spine immobilisation. Clinical practice ranges from one-piece hard or semi-rigid collars (eg. Stifneck) to more comfortable two-piece collars (eg. Philadelphia), tape and sandbags alone, or ‘triple immobilisation’ (collar, sandbags and tape). It is perhaps the obsessive adherence to the latter in the absence of a single piece of supportive evidence that I find bewildering.
Fortunately most Australian practice I’ve witnessed settles on a collar or manual immobilisation, with early application of a two-piece collar in those patients who require prolonged immobilisation.
The College guideline provides a helpful and pragmatic summary of the evidence to date and a digestible list of recommendations that could guide both departmental practice and postgraduat exam revision.
Guideline on the management of alert, adult patients with potential cervical spine injury in the Emergency Department
College of Emergency Medicine 2010 (PDF)
Helicopters and trauma: systematic review
In the midst of reconfiguring its trauma systems, the United Kingdom’s National Health Service needed to evaluate the cost effectiveness of helicopter emergency medical services (HEMS). A systematic literature review was undertaken of all population-based studies evaluating the impact on mortality of helicopter transfer of trauma patients from the scene of injury. The authors also attempted to analyse whether it is the helicopter as a transport platform or the standard of the emergency medical service that accounts for any differences seen.
A search of the literature revealed 23 eligible studies. 14 of these studies demonstrated a significant improvement in trauma patient mortality when transported by helicopter from the scene. 5 of the 23 studies were of level II evidence with the remainder being of level III evidence.
Only one eligible study assessed HEMS in the UK. The other papers reported data from the USA, Italy, Australia, the Netherlands, Germany and South Africa.
The majority of studies show a mortality benefit with HEMS: fourteen studies reported results that demonstrated a significant mortality rate improvement with HEMS, four reported data that did not reach significance and five did not report whether results reached significance.
The authors suggest this variation may be a result of any of the following factors, and provide a thorough discussion of the literature pertaining to each of them:
- Transport of a physician to the scene
- Transport of advanced airway skills to the scene
- Transporting a team experienced in managing trauma patients
- Triage to the definitive treatment facility
The full text of the review is available at the link below.
Is it the H or the EMS in HEMS that has an impact on trauma patient mortality? A systematic review of the evidence
EMJ 2010;27(9):692-701 (Free Full Text)
Paediatric airway gems
Dr Rich Levitan has made an enormous contribution to the science and practice of emergency airway management, as his bibliography demonstrates. In a new article in Emergency Physicians Monthly entitled ‘Demystifying Pediatric Laryngoscopy’, Rich covers some great tips for optimising laryngoscopic view in kids.
Check this excerpt out for an example:
“During laryngoscopy in infants the epiglottis and uvula are often touching; the epiglottis may be located within an inch of the mouth. Often the epiglottis lies against the posterior pharynx, and it is critical to have a Yankauer to dab the posterior pharynx as the laryngoscope is advanced. Hyperextension of the head pushes the base of tongue and epiglottis backwards against the posterior pharyngeal wall, and makes epiglottis identification more difficult”
Gems like this come thick and fast when you hear or read what Rich has to say. Seven years ago I was left reeling after finishing his ‘Airway Cam Guide to Intubation and Practical Emergency Airway Management‘ which profoundly influenced the way I practice and teach emergency airway skills, including on the Critical Care for Emergency Physicians course.
I’ve finally gotten round to booking a place on one of his courses in March in Baltimore. I’ll let you know how it goes. In the mean time, I’d like to point you toward his training videos as a great educational resource, like this one that demonstrates for novice laryngoscopists the difference between the appearances of trachea and oesophagus, the former having recognisable, defined posterior cartilagenous structures:
Demystifying Pediatric Laryngoscopy
Emergency Physicians Monthly January 19, 2011
A French FIRST in pre-hospital medicine
A contribution has been made to the literature supporting physician intervention in some pre-hospital trauma patients, in the form of the FIRST study: French Intensive care Recorded in Severe Trauma. 
Not exactly the class 1 evidence we’d (well, I’d) like to see, but a prospective study from France comparing outcomes in patients treated by routine pre-hospital providers with those managed in the field by emergency physicians working for SMUR (Service Mobile d’Urgences et de Réanimation). Primary outcome was 30-day mortality. Only patients admitted to an ICU were included, and researchers were not blinded to which group (SMUR vs nonSMUR) patients belonged. A large group of SMUR patients (2513) was compared with a much smaller (190) nonSMUR group.
Patients were sicker in the SMUR group (lower GCS and SpO2, higher Injury Severity Score, higher frequency of abnormal pupils). Unadjusted mortality was not significantly different but when adjustment for ISS and physiological status was made (I don’t really understand how this was done), SMUR care was significantly associated with a reduced risk of 30-day mortality (OR: 0.55, 95% CI: 0.32-0.94, p = 0.03).
Lots of interesting points in this study, most of which ask more questions that they answer. The French pre-hospital physicians have an aggressive approach to trauma resuscitation, doing rapid sequence intubation in more than a half of their patients and even starting catecholamine infusions as a fluid-sparing strategy in shocked patients. The full text link is worth a read for those interested in this area of medicine.
Medical pre-hospital management reduces mortality in severe blunt trauma: a prospective epidemiological study
Critical Care 2011, 15:R34
Full text as provisional PDF
RV involved in AMI more often than you think
We know that inferior STEMI may be complicated by right ventricular involvement, which is why I whack a V4R lead on all my inferior AMI patients. A recent study using cardiac magnetic resonance imaging showed that RV oedema and regional or global RV dysfunction were common in anterior infarcts too, although the proportion significantly decreased at four month follow up.
RV abnormalities are contiguous to the jeopardized LV myocardium and do not occur exclusively in inferior LV infarcts, but are found in up to 33% of anterior LV infarcts as well. The presence of RV ischemic injury is associated with early RV dysfunction as well as with RV functional recovery at follow-up.
Right Ventricular Ischemic Injury in Patients With Acute ST-Segment Elevation Myocardial Infarction: Characterization With Cardiovascular Magnetic Resonance.
Circulation. 2010 Oct 5;122(14):1405-12
Improved survival with modified CPR
A large randomised controlled trial1 on out-of-hospital cardiac arrest patients compared standard CPR with CPR augmented by two modifications:
- active compression-decompression using a hand-held suction device to compress the chest. The device is attached to the chest of the patient during CPR and the rescuer actively lifts the chest upwards after each compression, which are done at a rate of 80/min
- augmented negative intrathoracic pressure using an impedance threshold device, which is a valve that limits passive air entry into the lungs during chest compressions, thereby reducing intrathoracic pressure and increasing blood flow to vital organs
The primary study endpoint was survival to hospital discharge with favourable neurological function.
Funding issues resulted in premature cessation of the study. 47 (6%) of 813 controls survived to hospital discharge with favourable neurological function compared with 75 (9%) of 840 patients in the intervention group (odds ratio 1·58, 95% CI 1·07–2·36; p=0·019]. 74 (9%) of 840 patients survived to 1 year in the intervention group compared with 48 (6%) of 813 controls (p=0·03), with equivalent cognitive skills, disability ratings, and emotional-psychological statuses in both groups. The overall major adverse event rate did not differ between groups, but more patients had pulmonary oedema in the intervention group (94 [11%] of 840) than did controls (62 [7%] of 813; p=0·015).
An accompanying editorial2 points out that previous studies in animal models of cardiac arrest gave reassuring results for both devices individually and when used together, but results from clinical trials in patients have been mixed for each device when used individually:
- For compression-decompression CPR, a systematic review pooled the existing data for such CPR versus standard CPR in 4162 patients and found no difference in short-term mortality (relative risk 0·98, 95% CI 0·94–1·03) or survival to hospital discharge (0·99, 0·98–1·01). The 2010 CPR guidelines for the USA and Europe do not recommend the use of compression–decompression CPR alone.
- The most current systematic review for the impedance-threshold device showed a significantly improved early survival (relative risk 1·45, 1·16–1·80), and a short-term improved neurological outcome (2·35, 1·30–4·24); however, improved long- term survival did not reach conventional statistical significance (1·48, 0·91–2·41).
The Resuscitation Outcomes Consortium (ROC) PRIMED study3 showed no survival benefit in 8718 patients randomised to standard CPR with an active or sham impedance-threshold device (the Consortium includes the same investigators as the Lancet paper). This was published as an abstract in Circulation recently.
The editorialist has reservations regarding a change in clinical practice resulting from this new study, partly because the trial was stopped prematurely and enrolment of a larger cohort could have changed the findings, and partly because the open use of both devices might have unintentionally introduced bias into the study. Further validation is recommended.
1. Standard cardiopulmonary resuscitation versus active compression-decompression cardiopulmonary resuscitation with augmentation of negative intrathoracic pressure for out-of-hospital cardiac arrest: a randomised trial
Lancet 2011;377:301-11
2. Augmented CPR: rescue after the ResQ trial
Lancet. 2011 Jan 22;377:276-7
3. The Resuscitation Outcomes Consortium ROC) PRIMED Impedance Threshold Device (ITD) Cardiac Arrest Trial: A Prospective, Randomized, Double-Blind, Controlled Clinical Trial
Circulation 2010; 122: 2215–26 (abstr)
Open thoracostomy
Not a new paper to cite here, just a collection of resources that refer to open thoracostomy in trauma.
A longstanding practice by some European and Australasian HEMS physicians, open thoracostomy is essentially a chest tube procedure without the actual intercostal catheter: the surgical incision is made, blunt dissection is performed, and the pleura penetrated. The wound is then left open.
This is a rapid way of decompressing a tension pneumothorax in a critically injured trauma patient who is intubated. The positive pressure ventilation prevents the thoracostomy wound from acting as an open, ‘sucking’, chest wound.
In many pre-hospital services this is the preferred approach to pleural decompression in an intubated patient, and also forms part of the approach to resuscitation in traumatic cardiac arrest.
Some principles to consider are:
- A tube and drainage system are not necessary for the drainage of air, but should be used if there is signficant haemothorax
- The tissues may re-appose during transport so physiological deterioration should prompt a re-fingering of the thoracostomy to re-establish the drainage tract and allow air to escape
- Standard intravenous cannula devices may be shorter than the distance from chest wall to pleural space in many adults, adding to the inadequacy of needle decompression
- Signs of tension pneumothorax are rarely if ever as obvious as the textbooks suggest – unexplained shock or hypoxaemia in a patient with actual or probably thoracic trauma should prompt consideration of pleural decompression even in the absence of obvious clinical signs of pneumothorax – subtle evidence only may exist, such as palpable subcutaneous emphysema
- This should only be done in intubated patients undergoing positive pressure ventilation!
This video shows the procedure, done by a relative beginner; a slightly larger incision with more assertive dissection would make it faster and more effective
Not yet heard Scott Weingart’s excellent podcast on traumatic arrest, which includes open, or ‘finger’, thoracostomy? You can find it here
Thoracostomy references
Simple Thoracostomy Avoids Chest Drain Insertion in Prehospital Trauma
J Trauma 1996 39(2):373-374
Simple thoracostomy in prehospital trauma management is safe and effective: a 2-year experience by helicopter emergency medical crews
European Journal of Emergency Medicine 2006, 13:276–280
Prehospital thoracostomy
European Journal of Emergency Medicine 2008, 15:283–285
Chest decompression during the resuscitation of patients in prehospital traumatic cardiac arrest
Emerg. Med. J. 2009;26;738-740
Life-saving or life-threatening? Prehospital thoracostomy for thoracic trauma
Emerg Med J 2007;24:305–306
Pre-Hospital and In-Hospital Thoracostomy: Indications and Complications
Ann R Coll Surg Engl. 2008 January; 90(1): 54–57
Needle decompression is inadequate:
Needle Thoracostomy in the Treatment of a Tension Pneumothorax in Trauma Patients: What Size Needle?
J Trauma. 2008;64:111–114
Pre-hospital management of patients with severe thoracic injury
Injury 1995 26(9):581-5
Sux vs Roc in ED RSI
Suxamethonium and rocuronium were compared in a database of prospectively recorded cases of RSI in the emergency department.
A total of 327 RSI were included in the final analyses. All patients received etomidate as the induction sedative and were successfully intubated. Of these, 113 and 214 intubations were performed using succinylcholine and rocuronium, respectively.
- The rate of first-attempt intubation success was similar between the succinylcholine and rocuronium groups (72.6% vs. 72.9%, p = 0.95).
- Median doses used for succinylcholine and rocuronium were 1.65 mg/kg (interquartile range [IQR] = 1.26–1.95 mg/kg) and 1.19 mg/kg (IQR = 1–1.45 mg/kg), respectively.
- The median dose of etomidate was 0.25 mg/kg in both groups.
In this study succinylcholine and rocuronium were equivalent with regard to first-attempt intubation success in the ED. This finding is consistent with previous investigations that used doses between 0.9 and 1.2 mg/kg and found similar intubating conditions to succinylcholine at these higher doses; subgroup analyses of studies using a lower rocuronium dose of 0.6 to 0.7 mg/kg had a relative risk favoring succinylcholine for excellent intubating conditions.
The low (in my view) rate of first-attempt intubation success in both groups was (72.6% vs. 72.9%), does make one wonder whether the intubating clinicians optimised their strategy for first-pass success.
Comparison of Succinylcholine and Rocuronium for First-attempt Intubation Success in the Emergency Department
Acad Emerg Med. 2011;18:11-14