This is part of a recurring series examining landmark articles in Emergency Medicine, in the style of ALiEM’s 52 Articles.
Discussing: “Prospective Multicenter Evaluation of the Pulmonary Embolism Rule-out Criteria.” (J Thromb Haemost 2008; Kline JA et al.)
- Pulmonary Embolism Rule-out Criteria (PERC):
- age < 50,
- heart rate < 100 bpm
- SaO2 < 95%
- no hemoptysis
- no estrogen use
- no surgery/trauma requiring hospitalization within 4 weeks
- no unilateral leg swelling
- no prior venous thromboembolism
2) PERC in combination with clinical gestalt for low suspicion of pulmonary embolism (PE) reduces the probability of venous thromboembolism (VTE) to below 2%.
Chest pain is the most common emergency department chief complaint. The differential diagnosis is vast, and includes high acuity conditions (such as myocardial infarction, aortic aneurysm, and pulmonary embolism) down to low acuity conditions (such as reflux, muscle strain and anxiety.) Pulmonary embolism is one of the high risk clinical conditions that should not be missed. However, determining which patient should or should not be worked up for pulmonary embolism can be difficult. Continue reading
Two cases this week! Thank you to Dr. David Kaplan for submitting the first case, while the second case was one seen by myself and Dr. Paul Cheung.
58 y/o male sustained blunt force trauma to the lateral aspect of his right knee. On exam, there is a mild right knee effusion, but no obvious deformities. Pain with ROM. Neurovascularly intact. No ligamentous laxity appreciated. X-rays of the right knee are obtained:
22 y/o male sustained a gunshot wound to the right knee. On exam, there is an entrance wound on the posterior-lateral aspect of the knee, but no exit wound. There is pain with ROM of the knee and a mild effusion is appreciated. No obvious deformities. Neurovasculary intact. No ligamentous laxity appreciated. Initial plain films demonstrate the bullet lodged in the mid-thigh. Physical exam findings and x-rays of the right knee:
Given concern for an open joint, an aspiration is performed prior to irrigation, and the following aspirate is obtained:
What’s the diagnosis?
1. The final Canadian C-spine Rule comprises three questions:
A.) Is there a high-risk factor that mandates radiography such as: age≥65, dangerous mechanism, or paresthesias in extremities?
B.) Is there any low-risk factor that allows safe assessment of range of motion such as: simple rear end MVC, sitting position in ED, ambulatory at any time since injury, delayed onset of neck pain, or absence of midline C-spine tenderness?
C.) Is the patient able to actively rotate neck 45° to the left and right?
- The Canadian C-Spine Rule was tested on a convenience sample of 8,924 alert and stable trauma patients in 10 Canadian emergency departments with 151 cases of clinically significant C-spine injury and proved to have a sensitivity of 100% (95% CI: 98-100%) and a specificity of 42.5% (95% CI: 40-44%).
Less than three percent of trauma series yield a positive result.
According to the data compiled by the researchers in the Canadian CT Head and C-Spine Study the use of C-spine radiography is quite variable among emergency physician providers based on local culture and the overall cost of C-spine radiography is in the multi-millions. Their research demonstrated that less than three percent of trauma series yield a positive result. Continue reading
This is the first in a blog series that will explore landmark articles in Emergency Medicine.
- Patients meeting the following five simple clinical criteria are safe to clear without cervical spine imaging following blunt trauma:
- No focal neurologic deficit
- Normal alertness
- No intoxication
- No midline posterior bony cervical spine tenderness, and
- No painful distracting injury
- The sensitivity and specificity of the NEXUS criteria for detecting low probability injury and avoiding unnecessary imaging was 99 and 12.9 percent respectively, with a negative predictive value of 99.8 percent for the detection of clinically significant injuries.
Level of evidence: 1 (Prospective cohort trial)
Based on the ACEP grading scheme for diagnostic questions the NEXUS trial receives a class of evidence rating of 1.
Blunt trauma is a frequent cause of emergency department visits. However, the overall prevalence of cervical spine injury is generally only between 2-4% (2.4% in the NEXUS cohort). The goal of the NEXUS group was to create a simple clinical tool with which to risk stratify patients following blunt trauma, thereby reducing unnecessary cervical spine imaging and subsequently improving patient care through cost-reduction and a decrement in the downstream oncogenic risk secondary to radiation exposure. Continue reading