Tag Archives: hemorrhage

Bleeding and Pelvic Fractures

Arterial bleeding from a pelvic fracture is more common than previously thought. The doctor books used to say that 10% of bleeding was arterial and 90% was venous, so angiographic techniques were seldom used unless there was clinical evidence of blood loss. 

It looks like arterial bleeding occurs more frequently than we think. Here are tips that help you identify patients at risk:

  • What type of mechanism caused the fracture? Anterior-posterior compression and vertical shear are the most common.
  • Are the vital signs stable? If not, rule out the other four likely sources first (chest, abdomen, multiple extremity fractures, external). Then blame the pelvis.
  • Is the fracture open? Arterial bleeding is very likely.
  • How old is the patient? Elderly patients are more likely to have arterial bleeding, especially from gluteal artery branches.
  • What part of the pelvis is broken? If major sacral fractures, SI joint disruption or separation of the symphysis is present, think arterial bleeding.
  • Are there CT abnormalities? A vascular blush or large hematoma indicates significant bleeding.

The most common bleeding sites are the gluteal and pudendal arteries. The gluteal is in proximity to the SI joint, so this can be torn if the SI joint is damaged or the sacrum is fractured. The pudendal can be injured with ramus fractures, especially when the symphysis is widened.

If the patient can be reasonably stabilized, then a trip to interventional radiology is mandatory. Operative management is not very successful, so patients with blood pressure lability or controllable hypotension should go to IR. All active bleeding and arterial cutoffs should be embolized thoroughly.

Images: On the left is the portable plain image of a vertical shear pelvic fracture. The arrows on the right point to two areas of vascular blush.

Pelvic arterial bleeding

How Accurate is EMS at Estimating Blood Loss in the Field?

EMS providers are the trauma professional’s eyes and ears when providing transportation from the scene of an accident. We rely on their assessment of the mechanism of injury and the amount of blood lost. We tend to believe in the accuracy of those assessments.

A study was carried out that tested EMS personnel on their ability to accurately estimate specific amounts of blood that were left at a simulated accident scene. The blood volumes tested were 500cc, 1000cc, 1500cc and 2100cc. A total of 92 professionals participated, and there was an even split into basic EMTs (34%), intermediate/critical care EMTs (33%) and paramedics (31%). Experience levels were as follows: 0-5 years 43%, 6-10 years 30%, >10 years 31%.

The results were as follows:

  • 87% underestimated the quantity of blood
  • 9% overestimated
  • 4% guessed the exact amount
  • Experience or credentialing level did not matter

Only 8% of the subjects were within 20% of the actual volume, and an additional 19% were within 50%. In general, most medics underestimated the amount of blood lost, and their guesses were worse with higher volumes. The median guess for the 2100cc loss group was only 700cc!

EMS Blood Loss Estimates

The bottom line: Visual estimates of blood loss are extremely inaccurate, and are most likely  underestimates. Physicians in the ED should rely on exam and physiology to help determine the amount of blood loss. For safe measure, multiply the reported blood loss of the EMT or paramedic by 2 or 3 to get a realistic number.

Reference: Patton et al. Accuracy of Estimation of External Blood Loss by EMS Personnel. J Trauma 50(5), 914, 2001.