Ultrasound Guided Versus Palpation Guided Cricothyrotomy With Poorly Defined Anatomical Landmarks

A Comparison of Ultrasound Versus Digital Palpation Guided Cricothyrotomy in Subjects With Poorly Defined Anatomical Landmarks

Inability to provide oxygen to the patient remains the most fearful anesthesia-related mishap. Cricothyrotomy (CT) is an infrequently performed but life saving procedure for an anesthesiologist, who is encountered with this situation. The current method of cricothyrotomy relies on digital palpation (DP). Several patient populations, including morbidly obese, short neck, radiation to and previous neck surgeries, have difficult landmarks for this procedure. Ultrasound (US) technology has been used in the past to visualize landmarks for cricothyrotomy, but there is no study which has examined the role of ultrasound in patients who have obscure landmarks. There is no data related to the performance of ultrasound guided cricothyrotomy in these patients. In this study, we aimed to determine the outcomes of CT performed on human cadavers using US-guidance, compared to conventional DP, of anatomical landmarks. In particularly, complication rates, failure to cannulate, correct placement of the device and insertion time of CT were assessed.

For each cadaver - epidemiological data (age, sex) and morphometric data (Body Mass Index, neck circumference, thyromental distance)

The primary outcome measure was the complication rate as assessed by the severity of injuries; defined as the incidence and severity of posterior laryngeal and tracheal wall injuries, as graded by two anesthesiologists using the grading system described by Murphy et al,( none (no injury); mild (< 5 mm laceration); moderate (> 5mm laceration or partial puncture); severe (> 10 mm laceration or full puncture)). For clinical relevance and analysis of data we dichotomized the scale to none-mild and moderate - severe injuries.

The secondary outcomes include: 1) insertion time, measured in seconds (s) from the time of palpation of the skin to insertion of the Portex device in the trachea; 2) failure, with a 'failure' defined as any attempt in which the trachea was not cannulated, or which required > 300 s to perform; and 3) correct land-marking, defined as having the Portex device inserted via the CM.

Inclusion Criteria:

• Residents who are novice to the application of ultrasound in difficult airway scenarios
• Cadavers with difficult and imposible landmarks identification

Exclusion Criteria:

• Anethesiologist with previous experience in CT, manual or ultrasound assisted
• Patients with easily identifiable landmarks