Helicopters and trauma: systematic review

January 30, 2011 by  
Filed under All Updates, EMS, Resus, Trauma

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:

  1. Transport of a physician to the scene
  2. Transport of advanced airway skills to the scene
  3. Transporting a team experienced in managing trauma patients
  4. 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

January 28, 2011 by  
Filed under All Updates, EMS, ICU, Kids, Resus

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

Oldest observed galaxy

January 26, 2011 by  
Filed under Fascinomata

Comments Off

From World News Australia

Astronomers said they had snared an image of what may be the oldest galaxy ever seen, a starry cluster that came into being when the universe was still a baby.

The tiny smudge of light captured by the orbiting Hubble telescope took 13.2 thousand million years to reach Earth, which means the galaxy was born some 480 million years after the Big Bang that created the cosmos.

Read more

A French FIRST in pre-hospital medicine

January 25, 2011 by  
Filed under All Updates, EMS, Trauma

Comments Off

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

January 24, 2011 by  
Filed under Acute Med, All Updates, Resus

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.

T2w image of patient with LAD occlusion. Hyperintense appearance of jeopardised anteroseptal and anterior LV myocardium (arrowheads), extending to adjacent RV lateral free wall (arrows)

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

January 23, 2011 by  
Filed under Acute Med, All Updates, EMS, Resus

Comments Off

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

January 22, 2011 by  
Filed under All Updates, EMS, Resus, Trauma

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

January 18, 2011 by  
Filed under All Updates, ICU, Resus

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

Algorithm for Body Packers

January 15, 2011 by  
Filed under Acute Med, All Updates, Guidelines, Resus

‘Mules’ or body packers are people who transport illegal drugs by packet ingestion into the gastrointestinal tract. A large study of body packers apprehended by United State Customs officials at JFK International Airport, New York describes experience with body packers and an algorithm for conservative and surgical management.

Of 56 patients requiring admission out of a total of 1250 subjects confirmed to be body packers, 25 patients (45%) required surgical intervention, whereas 31 patients (55%) were successfully managed conservatively.

Diagnosis:

  • Plain abdominal x-ray was diagnostic in 49 patients (88% of all hospitalised patients).
  • Non-contrast CT of the abdomen and pelvis is required if AXR is negative
  • Forty-eight per cent of body packers had positive urine toxicology for illicit substances.

Management:

  • Indications for intervention included:
  • bowel obstruction
  • packet rupture/toxicity
  • delayed progression of packet transit on conservative management.
  • Patients with packets found predominantly in the proximal gastrointestinal tract failed conservative management more frequently than those with packets found in the distal gastrointestinal tract.

Multiple intraoperative manoeuvres were used to remove the foreign bodies:

  • gastrotomy
  • enterotomy
  • colotomy.

Wound infection was the most common complication and is associated with distal enterotomy and colotomy.

The authors recommend a confirmatory radiological study to demonstrate complete clearance of packets

Establishment of a definitive protocol for the diagnosis and management of body packers (drug mules).
Emerg Med J 2011;28:98-10

Hole in the head? Don’t waste the window!

January 11, 2011 by  
Filed under All Updates, ICU, Ultrasound

Zampieri and colleagues from Brazil report the use of brain ultrasound in two ICU patients who had had hemicraniectomies.

One of the patients had a subarachnoid haemorrhage with hydrocephalus and an infarct due to vasospasm requiring hemicraniectomy, who subsequently deteriorated with decreasing ventricular catheter drainage, raising suspicion of acute hydrocephalus. Brain ultrasonography confirmed moderate hydrocephalus which was seen to improve after catheter desobstruction.

a Ultrasonography showing moderate hydrocephalus with the catheter tip inside lateral ventricle (white arrow). b Image after catheter cleaning showing the decompressed lateral ventricle

The authors note: ‘standard ultrasonography can be performed through a hemicraniectomy field and may be helpful in a small group of patients. Since decompressive hemicraniectomy is increasingly being used in critical care medicine, bedside evaluation of the brain using the hemicraniectomy as an insonation window could be useful as a noninvasive triage tool and reduce the need for patient transport to the imaging center.’

Use of ultrasonography in hemicraniectomized patients: a report of two cases
Intensive Care Med. 2010 Dec;36(12):2161-2

Not got a hole in the skull? Could try a bony ultrasound window – compare the clear scans above with this scan of an extradural haematoma

Next Page »