Ultrasound Improves Cricothyrotomy Success in Cadavers with Poorly Defined Neck Anatomy: A Randomized Control Trial

Anesthesiology. 2015 Nov;123(5):1033-41. doi: 10.1097/ALN.0000000000000848.

Abstract

Background: Misidentification of the cricothyroid membrane in a "cannot intubate-cannot oxygenate" situation can lead to failures and serious complications. The authors hypothesized that preprocedure ultrasound-guided identification of the cricothyroid membrane would reduce complications associated with cricothyrotomy.

Methods: A group of 47 trainees were randomized to digital palpation (n = 23) and ultrasound (n = 24) groups. Cricothyrotomy was performed on human cadavers by using the Portex device (Smiths Medical, USA). Anatomical landmarks of cadavers were graded as follows: grade 1-easy = visual landmarks; 2-moderate = requires light palpation of landmarks; 3-difficult = requires deep palpation of landmarks; and 4-impossible = landmarks not palpable. Primary outcome was the complication rate as measured by the severity of injuries. Secondary outcomes were correct device placement, failure to cannulate, and insertion time.

Results: Ultrasound guidance significantly decreased the incidence of injuries to the larynx and trachea (digital palpation: 17 of 23 = 74% vs. ultrasound: 6 of 24 = 25%; relative risk, 2.88; 95% CI, 1.39 to 5.94; P = 0.001) and increased the probability of correct insertion by 5.6 times (P = 0.043) in cadavers with difficult and impossible landmark palpation (digital palpation 8.3% vs. ultrasound 46.7%). Injuries were found in 100% of the grades 3 to 4 (difficult-impossible landmark palpation) cadavers by digital palpation compared with only 33% by ultrasound (P < 0.001). The mean (SD) insertion time was significantly longer with ultrasound than with digital palpation (196.1 s [60.6 s] vs. 110.5 s [46.9 s]; P < 0.001).

Conclusion: Preprocedure ultrasound guidance in cadavers with poorly defined neck anatomy significantly reduces complications and improves correct insertion of the airway device in the cricothyroid membrane.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Anesthesia / methods
  • Anesthesia / standards*
  • Cadaver
  • Cricoid Cartilage / diagnostic imaging*
  • Cricoid Cartilage / surgery
  • Female
  • Humans
  • Internship and Residency / methods
  • Internship and Residency / standards
  • Intubation / methods
  • Intubation / standards*
  • Male
  • Neck / anatomy & histology
  • Neck / diagnostic imaging*
  • Palpation / methods
  • Palpation / standards
  • Thyroid Cartilage / diagnostic imaging*
  • Thyroid Cartilage / surgery
  • Ultrasonography, Interventional / methods
  • Ultrasonography, Interventional / standards*