As we mentioned in the podcast that accompanied our most recent post, an injury that is critical to identify in blunt trauma yet easy to miss or forget is pelvic fractures and pelvic trauma. Significant injuries occurring to the pelvic ring usually involved high mechanisms of injury such as high speed MVCs, motorcycle crashes, pedestrian struck, and falls from significant height. Pelvic fractures can be associated with a significant amount of bleeding, hypotension, and increased mortality. Mortality for all trauma patients with pelvic trauma ranges from 5-30%. If there is associated hypotension, mortality rises to 10-42%.
Pelvic fractures can be classified based on the mechanism of injury:
- Lateral compression (60-70%)
- Anterior-posterior compression (15-20%) aka “open book”
- Vertical shear injury (5-15%)
Bleeding in these injuries is thought to arise from injuries to the sacral venous plexus, from the bone fragments themselves, or from injuries to the iliac vessels (arterial or venous). It is thought that application of external, circumferential compression can stabilize pelvic fractures, reduce pelvic volume, reduce hemorrhage, and thereby improve patient outcomes and mortality. BestBets.org took a look at the topic of pelvic binding devices in 2013. Regarding stabilization of pelvic fractures, they reviewed studies that looked primarily at symphyseal diastasis and reduction of horizontal displacement. They found overall that the evidence was generally poor in quality, but found that cadaveric models did demonstrate the ability of devices like the T-Pod carried on AirCare to reduce symphyseal diastasis. BestBets.org also reviewed articles that sought to demonstrate the effect of pelvic binders on hemorrhage, hemodynamics, and mortality. They found no high quality studies that addressed these outcomes (studies were limited by lack of comparison groups, heterogenous treatment strategies, and small numbers). Case series have reported significantly improved hemodyanmics with the application of pelvic binders but no studies have demonstrated improved mortality or decreased rates of blood transfusion.
Where does that leave us?
Well, when evidence is lacking, prior experience usually guides our actions. Few studies have looked at harms associated with the application of a T-Pod like device, but it would be anticipated that the harms would be few. In general, a fair approach to these patients is that anyone with pelvic pain or instability and a good mechanism of injury should be a candidate for a pelvic binder. Patients with signs of shock with a blunt mechanism of injury should probably have a pelvic binder placed prior to transporting them. Many flight nurses and physicians can relay experiences where removing a pelvic binder was followed immediately by significant drops in BP, increases in HR.
What is the proper way to place the T-Pod?
Several articles have looked at how placement of the T-Pod affects its ability to reduce pelvic volume and pubic symphyseal diastasis. Bonner, et al (2011) found in a retrospective study of patients at a military hospital over the course of 30 months that when the T-Pod is placed higher than the level of the greater trochanters, there is significantly increased widening at the pubic symphysis (22 mm difference from correct placement). Ideally the T-pod should be placed so that it circumferentially compresses the pelvis at the level of the greater trochanter. Take a look at the videos below for instruction on how to properly place the T-Pod
Procedural Slide Set
First Person Video
- ATLS Student Course Manual, 9th Edition. American College of Surgeons, 2012.
- Stewart, M. Pelvic compression devices: Panacea or myth? (2013) http://bestbets.org/bets/bet.php?id=2516
- Clarke, D. Stabilization of Pelvic Fractures (2013) http://bestbets.org/bets/bet.php?id=2424
- Bonner, T., Eardley, W., Newell, N., Masouros, S., Gibb, I., Clasper, J. (2011) Accurate placement of a pelvic binder improves reduction of unstable fractures of the pelvic ring. Journal of Bone and Joint Surgery of Britian. 93 (11): 1524-8. doi: 10.1302/0301-620X.93B11.27023.