About Michelle Lin, MD

ALiEM Founder and CEO
Professor and Digital Innovation Lab Director
Department of Emergency Medicine
University of California, San Francisco

Paucis Verbis card: Suture Materials

SutureSuturing is a common procedure performed in the ED, but we too often forget about the nuances of different suture materials. We get set in our practice patterns. This changed when our ED got the fast-absorbing gut suture for surface wounds, especially for pediatric patients. This makes a return visit for suture removal unnecessary because they quickly become absorbed over time. Increasingly, I have observed plastics surgeons using these for surface wound closure of the face and hands.

Has anyone else used absorbable sutures on the skin for wound closure?

With this new suture material in my armamentarium, I thought it’d be helpful to review suture types and suture removal times for non-absorbable sutures.

PV Card: Suture Materials


Go to ALiEM (PV) Cards for more resources.

By |2021-10-17T09:12:20-07:00Jan 7, 2011|ALiEM Cards|

Tricks of the Trade: Finding the wandering contact lens

ContactLensContact lens wearers are familiar with the phenomenon of the wandering lens. What should you do if you can’t visualize the contact lens of a patient, who presents with a “lost contact lens” in the eye? You have the patient look in all directions and you evert the eyelid, but still no contact lens can be found. The patient swears that it’s there because of the painful foreign-body sensation.

(more…)

By |2021-06-01T09:35:32-07:00Jan 5, 2011|Ophthalmology, Tricks of the Trade|

Paucis Verbis card: Subarachnoid hemorrhage high-risk characteristics

SAHIn Wednesday’s post about the Colorado Compendium, Graham mentioned a new 2010 BMJ article on the high-risk signs suggestive of subarachnoid hemorrhage by the gurus in clinical prediction rules in Canada.

We excessively work-up patients for a subarachnoid hemorrhage with a nonspecific headache and no neurologic deficitis. This is because it’s difficult to predict who is high, medium, and low risk for such a bleed. So we throw a wider net so that we don’t miss such a devastating diagnosis. This usually means a CT and LP for many patients with a headache.

In this 5-year multicenter study, the investigators identified clinical decision rules to help identify the higher-risk groups for a subarachnoid hemorrhage. They derived 3 models, based on recursive partitioning. Each has a negative predictive value of 100%.

Before thinking about seeing if your headache patient has any of these high-risk features, pay special attention to see if s/he would have met the inclusion and exclusion criteria of this study.

Inclusion criteria:

  • Neurologically intact adults (age ≥ 16 years) with a non-traumatic headache peaking within an hour.

Exclusion criteria:

  • History of ≥3 recurrent HA’s of same character/intensity
  • Referred from another hospital with confirmed SAH
  • Returned for reassessment of same HA which was already evaluated for SAH
  • Papilledema
  • New focal neurologic deficits
  • Previous dx of cerebral aneurysm or SAH
  • Previous dx of brain neoplasm
  • Known hydrocephalus

Although none of the models are validated as of yet, the cumulative list of clinical characteristics from these 3 models may be able to help you understand who may be at higher risk:

  • Age ≥ 40 years
  • Witnessed loss of consciousness
  • Neck pain or stiffness
  • Onset of HA with exertion
  • Arrival by ambulance
  • Vomiting
  • DBP ≥ 100 mmHg or SBP ≥ 160 mmHg

PV Card: Subarachnoid Hemorrhage – High Risk Characteristics

By |2021-10-17T09:15:59-07:00Dec 17, 2010|ALiEM Cards, Neurology|

Paucis Verbis card: Cervical spine imaging rules

CervicalCollarThere is constant debate on whether to image the cervical spine of blunt trauma patients. Fortunately, there are two clinical decision tools available to help you with your evidence-based practice.

The NEXUS and Canadian C-spine Rules (CCR) are both validated studies which both quote a high sensitivity (over 99%) in detecting clinically significant cervical spine fractures. Both studies primarily used plain films in evaluating their patients.

Sensitivity (%)Specificity (%)
NEXUS99.612.6
CCR99.445.1

 

NEXUS

National Emergency X-radiography Utilization Study

A patient’s neck can be clinically cleared safely without radiographic imaging if all five low-risk conditions are met:

  1. No posterior midline neck pain or tenderness
  2. No focal neurological deficit
  3. Normal level of alertness
  4. No evidence of intoxication
  5. No clinically apparent, painful distracting injury*

* Defined as “a condition thought by the clinician to be producing pain sufficient to distract the patients from a second (neck) injury. Examples may include, but are not limited to the following:

  1. Long bone fracture,
  2. A visceral injury requiring surgical consultation,
  3. A large laceration, degloving injury, or crush injury,
  4. Large burns, or
  5. Any other injury producing acute functional impairment

Physicians may also classify any injury as distracting if it is thought to have the potential to impair the patient’s ability to appreciate other injuries.”

Canadian C-spine Rules (CCR)

The basic approach in this flow-chart is to (1) make sure that the patient meets the same inclusion criteria as in the CCR study. Then (2) determine if there are high-risk findings. If so, go directly to imaging. (3) If there are no high-risk findings, check to see if the patient qualifies as a low-risk candidate where you might be able to clinically clear the c-spine without imaging. (4) If the patient is neither high or low risk, then the patient is moderate risk and requires imaging. Here’s a flow chart that I made to help you remember:


Go to ALiEM (PV) Cards for more resources.

Note: Many emergency physicians go straight to CT imaging for patients with neck tenderness and moderate/high risk findings. I personally rarely use the CCR algorithm because I can rarely remember all of the criteria. NEXUS is nice because of its simplicity. Where the CCR algorithm IS helpful is in clinical clearance of the low-risk patient with neck pain. I’ve cleared many patients who self-present with a whiplash mechanism (simple rear-end motor vehicle crash) and diffuse neck pain. By NEXUS criteria, you’d have to image them because they have neck tenderness. By CCR criteria, if they can actively rotate their neck 45 degrees left and right, they don’t have a clinically significant c-spine injury. No imaging needed.

By |2021-10-17T09:17:48-07:00Dec 10, 2010|ALiEM Cards, Orthopedic, Trauma|

Article review: Consensus methodologies in qualitative research

Strength in Numbers

What types of methodologies are used to develop a consensus statement? I’m in the midst of helping to write a consensus statement manuscript in education and ran into this great review article. It’s from the British Medical Journal in 1995. 

Basically, there are 2 general types of methodologies:

  • Delphi Process
  • Nominal Group Technique 

(more…)

By |2016-11-11T19:00:18-08:00Dec 6, 2010|Education Articles, Medical Education|

Paucis Verbis card: Dysphagia

DysphagiaDyphagia is a disorder of swallowing. It actually occurs in up to 10% of adults older than 50 years old. How can you determine the most likely causes for dysphagia? The secret is to obtain a thorough history and using the algorithm below, which I find really helpful from a review article in American Family Physician.

How do you read the figure?

  • Determine first if patient has oropharyngeal vs esophageal dysphagia.
  • Determine if mechanical (problem is solid foods only) vs neuromuscular (problem with liquids and solids)is more likely.

Tip:

  • Medications can cause dysphagia from esophageal mucosal injury or reduced lower esophageal sphincter tone.
  • CVA is most common cause of oropharyngeal dysphagia

Workup:

  • Endoscopy
  • Barium swallow
  • Consider esophageal pH probe, manometry

PV Card: Dysphagia


Adapted from [1]
Go to ALiEM (PV) Cards for more resources.

Reference

  1. Spieker M. Evaluating dysphagia. Am Fam Physician. 2000;61(12):3639-3648. [PubMed]
By |2021-10-17T09:20:02-07:00Dec 3, 2010|ALiEM Cards, Gastrointestinal|
Go to Top