Tag Archives: Trauma

Risk factors for cervical spine injury

Data from the Crash Injury Research Engineering Network (CIREN) database were analysed to identify epidemiologic and biomechanical risk factors for  cervical spinal cord and spinal column injuries. They showed:

  • Older case occupants are at an increased risk of cervical spine injury (CSI)
  • Rollover crashes and severe crashes led to a much higher risk of CSI than other types and severity of MVCs
  • Seat belt use is very effective in preventing CSI
  • Airbag deployment may increase the risk of occupants sustaining a CSI


BACKGROUND: : Motor vehicle collisions (MVCs) are the leading cause of spine and spinal cord injuries in the United States. Traumatic cervical spine injuries (CSIs) result in significant morbidity and mortality. This study was designed to evaluate both the epidemiologic and biomechanical risk factors associated with CSI in MVCs by using a population-based database and to describe occupant and crashes characteristics for a subset of severe crashes in which a CSI was sustained as represented by the Crash Injury Research Engineering Network (CIREN) database.
METHODS: : Prospectively collected CIREN data from the eight centers were used to identify all case occupants between 1996 and November 2009. Case occupants older than 14 years and case vehicles of the four most common vehicle types were included. The National Automotive Sampling System’s Crashworthiness Data System, a probability sample of all police-reported MVCs in the United States, was queried using the same inclusion criteria between 1997 and 2008. Cervical spinal cord and spinal column injuries were identified using Abbreviated Injury Scale (AIS) score codes. Data were abstracted on all case occupants, biomechanical crash characteristics, and injuries sustained. Univariate analysis was performed using a χ analysis. Logistic regression was used to identify significant risk factors in a multivariate analysis to control for confounding associations.
RESULTS: : CSIs were identified in 11.5% of CIREN case occupants. Case occupants aged 65 years or older and those occupants involved in rollover crashes were more likely to sustain a CSI. In univariate analysis of the subset of severe crashes represented by CIREN, the use of airbag and seat belt together (reference) were more protective than seat belt alone (odds ratio [OR] = 1.73, 95% confidence interval [CI] = 1.32-2.27) or the use of neither restraint system (OR = 1.45, 95% CI = 1.02-2.07). The most frequent injury sources in CIREN crashes were roof and its components (24.8%) and noncontact sources (15.5%). In multivariate analysis, age, rollover impact, and airbag-only restraint systems were associated with an increased odds of CSI. Using the population-based National Automotive Sampling System’s Crashworthiness Data System data, 0.35% of occupants sustained a CSI. In univariate analysis, older age was noted to be a significant risk factor for CSI. Airbag-only restraint systems and both rollover and lateral crashes were also identified as risk factors for CSI. In addition, increasing delta v was highly associated with CSIs. In multivariate analysis, similar risk factors were noted. Of all the restraint systems, seat belt use without airbag deployment was found to be the most protective restraint system (OR = 0.29, 95% CI = 0.16-0.50), whereas airbag-only restraint was associated with the highest risk of CSI (OR = 3.54, 95% CI = 2.29-5.46).
CONCLUSIONS: : Despite advances in automotive safety, CSIs sustained in MVC continue to occur too often. Older case occupants are at an increased risk of CSI. Rollover crashes and severe crashes led to a much higher risk of CSI than other types and severity of MVCs. Seat belt use is very effective in preventing CSI, whereas airbag deployment may increase the risk of occupants sustaining a CSI. More protection for older occupants is needed and protection in both rollover and lateral crashes should remain a focus of the automotive industry. The design of airbag restraint systems should be evaluated so that they are not causative of serious injury. In addition, engineers should continue to focus on improving automotive design to minimize the risk of spinal injury to occupants in high severity crashes
Occupant and Crash Characteristics for Case Occupants With Cervical Spine Injuries Sustained in Motor Vehicle Collisions
J Trauma. 2011 Feb;70(2):299-309

Balloon catheters for haemorrhage control

Something I keep up my sleeve (not literally) for managing some life-threatening vascular wounds prior to surgery is the use of a balloon catheter like a foley to tamponade haemorrhage. This paper looks at series of such attempts although they state: “Except for the base of the skull (naso/oropharynx), all catheters were de- ployed in the operating room.“, so not exactly emergency medicine / pre-hospital practice, but a useful reminder that this is an option when going immediately to the operating room isn’t:

BACKGROUND: : Balloon catheter tamponade is a valuable technique for arresting exsanguinating hemorrhage. Indications include (1) inaccessible major vascular injuries, (2) large cardiac injuries, and (3) deep solid organ parenchymal bleeding. Published literature is limited to small case series. The primary goal was to review a recent experience with balloon catheter use for emergency tamponade in a civilian trauma population.
METHODS: : All patients requiring emergency use of a balloon catheter to tamponade exsanguinating hemorrhage (1998-2009) were included. Patient demographics, injury characteristics, technique, and outcomes were analyzed.
RESULTS: : Of the 44 severely injured patients (82% presented with hemodynamic instability; mean base deficit = -20.4) who required balloon catheter tamponade, 23 of the balloons (52%) remained indwelling for more than 6 hours. Overall mortality depended on the site of injury/catheter placement and indwelling time (81% if <6 hours; 52% if ≥6 hours; p < 0.05). Physiologic exhaustion was responsible for 76% of deaths in patients with short-term balloons. Mortality among patients with prolonged balloon catheter placement was 11%, 50%, and 88% for liver, abdominal vascular, and facial/pharyngeal injuries, respectively. Mean indwelling times for iliac, liver, and carotid injuries were 31 hours, 53 hours, and 78 hours, respectively. Overall survival rates were 67% (liver), 67% (extremity vascular), 50% (abdominal vascular), 38% (cardiac), and 8% (face). Techniques included Foley, Fogarty, Blakemore, and/or Penrose drains with concurrent red rubber Robinson catheters. Initial tamponade of bleeding structures was successful in 93% of patients.
CONCLUSIONS: : Balloon catheter tamponade can be used in multiple anatomic regions and for variable patterns of injury to arrest ongoing hemorrhage. Placement for central hepatic gunshot wounds is particularly useful. This technique remains a valuable tool in a surgeon’s armamentarium.
A Decade’s Experience With Balloon Catheter Tamponade for the Emergency Control of Hemorrhage
J Trauma. 2011 Feb;70(2):330-3

Plasma:red cell ratios

In some circles, ‘wuntwuntwun’ is in danger of becoming the new dogma of trauma fluid replacement (ie. 1 unit of plasma and 1 unit of platelets for every unit of red cells). Since it takes longer to thaw some plasma than it does to throw in some O negative packed red cells, some really sick patients may be dead before they get the plasma, biasing comparisons that show a reduced mortality in patients who were still alive to receive plasma. This ‘survivor bias’ has been suggested as a reason that high plasma:red cell ratios are associated with mortality reduction, although this has been challenged.
The survivor bias explanation receives some new support by the following (small) study from Journal of Trauma:
BACKGROUND: In light of recent data, controversy surrounds the apparent 30-day survival benefit of patients achieving a fresh frozen plasma (FFP) to packed red blood cell (PRBC) ratio of at least 1:2 in the face of massive transfusions (MT) (≥10 units of PRBC within 24 hours of admission). We hypothesized that initial studies suffer from survival bias because they do not consider early deaths secondary to uncontrolled exsanguinating hemorrhage. To help resolve this controversy, we evaluated the temporal relationship between blood product administration and mortality in civilian trauma patients receiving MT.

METHODS: Patients requiring MT over a 22-month period were identified from the resuscitation registry of a Level I trauma center. Shock severity at admission and timing of shock-trauma admission, blood product administration, and death were determined. Patients were divided into high- and low-ratio groups (≥1:2 and<1:2 FFP:PRBC, respectively) and compared. Kaplan-Meier analysis and log-rank test was used to examine 24-hour survival.
RESULTS: One hundred three patients (63% blunt) were identified (66 high-ratio and 37 low-ratio). Those patients who achieved a high-ratio in 24 hours had improved survival. However, severity of shock was less in the high-group (base excess: -8.0 vs. -11.2, p=0.028; lactate: 6.3 vs. 8.4, p=0.03). Seventy-five patients received MT within 6 hours. Of these, 29 received a high-ratio in 6 hours. Again, severity of shock was less in the high-ratio group (base excess: -7.6 vs. -12.7, p=0.008; lactate: 6.7 vs. 9.4, p=0.02). For these patients, 6-hour mortality was less in the high-group (10% vs. 48%, p<0.002). After accounting for early deaths, groups were similar from 6 hours to 24 hours.
CONCLUSIONS: Improved survival was observed in patients receiving a higher plasma ratio over the first 24 hours. However, temporal analysis of mortality using shorter time periods revealed those who achieve early high-ratio are in less shock and less likely to die early from uncontrolled hemorrhage compared with those who never achieve a high-ratio. Thus, the proposed survival advantage of a high-ratio may be because of selection of those not likely to die in the first place; that is, patients die with a low-ratio not because of a low-ratio.
The authors state “The current study underscores the need for well-designed prospective studies to address the important question of which ratio results in improved survival and stresses the importance of timing of blood product administration as this may impact survival.
Improved survival after hemostatic resuscitation: does the emperor have no clothes?
J Trauma. 2011 Jan;70(1):97-102

Helicopters between hospitals

More National Trauma Databank analysis coming out in favour of helicopter transport: this time looking at interhospital transfer:

Background: Helicopter transport (HT) is frequently used for interfacility transfer of injured patients to a trauma center. The benefits of HT over ground transport (GT) in this setting are unclear. By using a national sample, the objective of this study was to assess whether HT impacted outcomes following interfacility transfer of trauma patients.

Methods: Patients transferred by HT or GT in 2007 were identified using the National Trauma Databank (version 8). Injury severity, resource utilization, and survival to discharge were compared. Stepwise logistic regression was used to determine whether transport modality was a predictor of survival after adjusting for covariates. Regression analysis was repeated in subgroups with Injury Severity Score (ISS) ≤15 and ISS >15.
Results: There were 74,779 patients transported by helicopter (20%) or ground (80%). Mean ISS was higher in patients transported by helicopter (17 ± 11 vs. 12 ± 9; p < 0.01) as was the proportion with ISS >15 (49% vs. 28%; odds ratio [OR], 2.53; 95% confidence interval [CI], 2.43-2.63). Patients transported by helicopter had higher rates of intensive care unit admission (54% vs. 29%; OR, 2.86; 95% CI, 2.75-2.96), had shorter transport time (61 ± 55 minutes vs. 98 ± 71 minutes; p < 0.01), and had shorter overall prehospital time (135 ± 86 minutes vs. 202 ± 132 minutes; p < 0.01). HT was not a predictor of survival overall or in patients with ISS ≤15. In patients with ISS >15, HT was a predictor of survival (OR, 1.09; 95% CI, 1.02-1.17; p = 0.01).
Conclusions: Patients transported by helicopter were more severely injured and required more hospital resources than patients transported by ground. HT offered shorter transport and overall prehospital times. For patients with ISS >15, HT was a predictor of survival. These findings should be considered when developing interfacility transfer policies for patients with severe injuries.
Helicopters Improve Survival in Seriously Injured Patients Requiring Interfacility Transfer for Definitive Care
J Trauma. 2011 Feb;70(2):310-4.

Neck movement in spite of collar

A cadaveric study using an artificially created unstable cervical spine injury has shown marked displacement of the vertebrae when cervical collars were applied, and when the bodies were moved in a way that simulated normal transfer and log-rolling. There was no comparison with a no-collar situation, so we can’t say from this that collars are necessarily bad, just that they’re no good in this cadaveric model. I like this statement by the authors:
A variety of collars, backboards, and other equipment and techniques are being used in an attempt to achieve spine stabilization, largely without any validation of efficacy when used in the presence of a severe cervical injury. Randomized, prospective clinical trial designs are challenging in this domain theless, basic cadaver studies can provide valuable insight into potential clinical efficacy.

"Severe unstable injuries were created in seven fresh whole human cadavers"

Even more musical to my ears is the editorial commentary by neurosurgery professor Richard L. Saunders, MD:
…the more compelling question is whether there is a place for collars in emergent protection of the injured cervical spine or are they simply a gimcrack***?
The incidence of second injuries to the spinal cord in the extraction of accident victims under the best of EMT performance is not known and would be difficult to determine. However, in an effort to minimize that incidence, paramedical gospel is the application of a cervical collar, maintaining the neck in in-line and in a neutral position. By definition, this gospel implies the deliberate movement of the neck to apply an orthotic known to be nonprotective. Furthermore, the neutral and in-line admonition implies that the patient’s neck position can be safely adjusted to “look better” without a shred of evidence that this might be a safer strategy than avoiding any unnecessary neck movement whatsoever….
…In a conclusion common to many small study reports, the authors recommend that more work should be done in this area. In my opinion that might be best in refinements of extraction methods with an eye to only that neck movement necessary to resuscitation, collar be damned.

Motion Within the Unstable Cervical Spine During Patient Maneuvering: The Neck Pivot-Shift Phenomenon
J Trauma. 2011 Jan;70(1):247-50
*** I confess never to have encountered this word before. According to the freedictionary.com, a gimcrack is ‘A cheap and showy object of little or no use; a gewgaw‘. Now, WTF is a gewgaw?!?!

Inadequate pre-hospital needle thoracostomy

The purpose of this study was to evaluate the frequency of inadequate needle chest thoracostomy in the prehospital setting in trauma patients suspected of having a pneumothorax (PTX) on the basis of physical examination.
This study took place at a level I trauma center. All trauma patients arriving via emergency medical services with a suspected PTX and a needle thoracostomy were evaluated for a PTX with bedside ultrasound. Patients too unstable for ultrasound evaluation before tube thoracostomy were excluded, and convenience sampling was used. All patients were scanned while supine. Examinations began at the midclavicular line and included the second through fifth ribs. If no sliding lung sign (SLS) was noted, a PTX was suspected, and the lung point was sought for definitive confirmation. When an SLS was noted throughout and a PTX was ruled out on ultrasound imaging, the thoracostomy catheter was removed. Descriptive statistics were calculated.

Image used with kind permission of Bret Nelson, MD, RDMS (click image for more great ultrasound images)

A total of 57 patients were evaluated over a 3-year period. All had at least 1 needle thoracostomy attempted; 1 patient underwent 3 attempts. Fifteen patients (26%) had a normal SLS on ultrasound examination and no PTX after the thoracostomy catheter was removed. None of the 15 patients were later discovered to have a PTX on subsequent computed tomography.
In this study, 26% of patients who received needle thoracostomy in the prehospital setting for a suspected PTX appeared not to have had a PTX originally, nor had 1 induced by the needle thoracostomy. It may be prudent to evaluate such patients with bedside ultrasound instead of automatically converting all needle thoracostomies to tube thoracostomies.
Inadequate needle thoracostomy rate in the prehospital setting for presumed pneumothorax: an ultrasound study
J Ultrasound Med. 2010 Sep;29(9):1285-9

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:

  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)

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

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