Ottawa Ankle Rules

This is part of a recurring series examining landmark articles in Emergency Medicine, in the style of ALiEM’s 52 Articles.

Discussing:  Stiell IG, et al. Decision Rules for the Use of Radiography in Acute Ankle Injuries. JAMA 1993; 269 (9): 1127 – 1132.

 X-Rays for ankle fractures? Is trouble a foot?

With a such a refined Canadian tool you can’t act like a fool.

 The Rules:

Ottawa Ankle

Main Points:

  1. The Ottawa ankle rule is an excellent screening tool for patients with ankle and foot injuries. In this study, it was found to have a sensitivity of 100 percent and is therefore unlikely to miss clinically significant ankle and midfoot injuries.
  2. These simple rules allowed physicians to safely reduce the number of radiographs ordered in patients with ankle and foot injuries by nearly a third.
  3. Based on the combined 1485 patients seen in the two stages the negative likelihood ratio for a fracture is estimated to be 0 for both the ankle and foot series rules!

Background:

Acute ankle injuries are one of the most common presenting complaints seen in the Emergency Department. Ankle radiographs are typically the second most commonly performed musculoskeletal examination, after the cervical spine. It was estimated that more than 5 million ankle radiographs are ordered annually in Canada and the USA with a cost of $500 creating a massive burden on the healthcare systems. Out of all of these images, treatable fractures are present in less than 15 percent of cases.

In 1992, Ian Stiell and his colleagues derived a clinical decision tool for the use of radiography in acute ankle and foot injuries. In the original study, thirty-two clinical variables were assessed for association with fractures seen on x-ray. Using these results, a set of rules were derived to determine if imaging was necessary for patients with ankle and foot injuries who met certain criteria. The goal of the study being reviewed here was to prospectively validate and potentially refine the decision rules to have the highest sensitivity possible, 100 percent, for identifying malleoli and midfoot fractures.

Methods:

The study was set up as a convenience survey and was prospectively administered in two stages: validation and refinement of the original rules, followed by validation of the refined rules in a new group of patients. For the study, injuries were subdivided into malleolar and midfoot zones. Patients who presented to the emergency department with pain or tenderness secondary to blunt ankle trauma due to any mechanism of injury were included. Patients were excluded if they were less than 18 years old, pregnant, has isolated skin injuries, were referred from outside facility with X-rays already completed, if injuries occurred more than 10 days ago, or if the patient had returned for reassessment of the injury.

Participants were evaluated by emergency medicine physicians who recorded their findings and interpretation of the decision rules on a standardized data collection sheet. All patients were then referred for radiography. Images were interpreted by radiologists who were blinded to the findings of the physician in the ED. Clinically significant fractures were defined as bone fragments greater than 3 mm in breadth, as avulsion fractures of 3 mm or less are not treated with plaster immobilization in the institutions involved in the study.

Data collected from the first stage was analyzed in order to refine the decision rules towards the objective of a sensitivity of 1.0. Each of the clinical variables were assessed for association with significant fractures in the ankle and foot radiographs. In the second stage, the sensitivity and specificity of the refined decision rules (see image above) was calculated and the accuracy and reliability of the physicians’ interpretation of the rules was determined. Continue reading

A True Orthopedic and Vascular Emergency

Case: A 76-year-old male presents after falling down a long flight of stairs. On exam the patient has multiple obvious external injuries, including a grossly deformed right shoulder with a large overlying hematoma. His chest x-ray and shoulder x-ray demonstrate a superiorly and laterally displaced right scapula, as well as a comminuted right scapular fracture and clavicle fracture. On further CT imaging, the patient has subtle widening of the scapulothoracic articulation.

OneQuestion: What potentially devastating injury should be considered in this patient?

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US articles: PTX in trauma, FAST for Thoracotomy, Pedi Hip Effusions

brownsound 2

Brown Ultrasound Tape Review:  10/15/15

Article 1: FAST Exam to Predict Survivors of ED Thoracotomy

Inabi, et al. FAST Ultrasound Examination as a Predictor of Outcomes After Resuscitative Thoracotomy. Annals of Surgery 262(3):512-518, 2015.

Fresh off the trauma surgical press last month, this study examined the utility of FAST exam (specifically parasternal and subxiphoid cardiac views) to predict positive outcomes (survival to discharge or organ donation) of ED resuscitative thoracotomy (RT).

This was a prospective cohort study at LA County/USC Medical Center. In 3.5 years, 187 patients arrived in traumatic arrest and underwent FAST and RT (that’s 4-5 thoracotomies a month – WOW!). They documented +/- pericardial fluid and +/-  cardiac motion. PGY2-4 EM residents performed the FAST exams after some formal training, and they were supervised by “faculty” – not clear if those were surgeons or EM attendings.

About ½ patients lost vitals at the scene and another ¼ both en route and in the ED. Overall survival – 6 patients (3.2%). Overall organ donation – 3 patients (1.6%). Cardiac motion on FAST was 100% sensitive for the identification of survivors and organ donors (and 73.7% specific).  While the tables and discussion include a lot on the presence or absence of pericardial fluid, this did not impact the sensitivity or specificity of FAST. If cardiac motion was absent, the likelihood of survival was 0.

Bottom line: Given that RT is such a high risk, low survival procedure, cardiac FAST can be used (with excellent sensitivity) to identify traumatic arrest patients with better odds of survival or organ donation from ED thoracotomy. No cardiac motion means pretty much no chance of survival or organ donation.


 

Article 2: Handheld E-FAST for Pneumothorax

Kirkpatrick, et al. Hand-Held Thoracic Sonography for Detecting Post-Traumatic Pneumothoraces: The Extended Focused Assessment With Sonography for Trauma (EFAST). Journal of Trauma 57:288-295, 2004.

This was another trauma surgery study out of Vancouver Hospital and Health Sciences Centre interested in the test characteristics of hand-held US to look for PTX in trauma patients. They compared EFAST examinations for PTX to:

(1) CXR results

(2) a “composite standard” of clinical information, which included some combination of CXR, CT if it happened, clinical course, and need for chest tubes/needle decompression

(3) CT alone (the gold standard for patients who had a CT).

This was a retrospective chart review on trauma patients (note – those who were in “physiologic extremis” with suspected PTX were excluded). All EFASTs were done by the attending trauma surgeon using a linear transducer. They looked for lung sliding or comet tail artifacts or color power Doppler evidence of pleural sliding in at least 3 rib spaces. PTX was diagnosed if neither sliding nor comet tail artifacts were seen.

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Orthopedic Review: Distal Radius Fracture Reduction

Case: 64 yo F presents to the Emergency Department after tripping over a curb and suffering a FOOSH (fall on outstretched hand) injury. There is obvious deformity about the wrist with associated swelling and tenderness. X-ray imaging reveals the following:

Her exam and imaging are consistent with a distal radius fracture. How do you treat this?

Page ortho?

Providing adequate analgesia, reduction of fracture, and proper splinting is well within the scope of EM practice, especially in the community setting. This post will review the technique of hematoma block for analgesia as well as the different techniques for reduction of distal radius fractures and application of splint.

Hematoma Block

  • Can be used alone or in combination with other analgesic modalities such as IV narcotics or benzodiazepines
  • Simple technique
  • Very few complications

 

But is hematoma block effective?

  • In 2011, prospective randomized controlled trial comparing hematoma block to conscious sedation with IV Propofol
  • 96 patients underwent randomization and researchers compared patients’ pain using VAS (visual analog scale) during the procedure and after the procedure
  • Patients who received Propofol had pain scores of 0 during the procedure compared to 0.97+/-0.7 in patients who received hematoma block
  • After the procedure, patients who received Propofol had pain scores of 2.72+/-0.7 compared to 2.25+/-0.2 in patients who received hematoma block
  • Patients who received hematoma block had significantly shorter ED stay times (0.9hrs vs 2.6 hrs)

Hematoma blocks result in similar analgesia as conscious sedation with IV Propofol AND leads to shorter ED stay times

Setting up for the procedure:

  • 10cc 1% Lidocaine
  • 10cc syringe with 2 large needles (one for drawing up Lidocaine, one for injecting)
  • Skin cleanser (betadine, Chloraprep, or alcohol wipe)

Procedure Technique:

  1. Identify the fracture site by palpating along the dorsal aspect of the forearm to feel for bony step-off. Cleanse this entire area thoroughly with skin cleanser.
  2. Insert needle attached to syringe filled with 10cc 1% Lidocaine at that site and advance needle along periosteum until needle falls into fracture site.
  3. Draw back on plunger to aspirate blood confirming the needle is in the fracture site.
  4. Inject 10cc Lidocaine into fracture site and remove needle.
  5. Allow 10-15min to pass to ensure full analgesic effect.

Continue reading