Sidesaddle Digital Intubation Technique

Improving on the traditional digital intubation technique with the “sidesaddle” technique

• Rarely taught, because rarely used now that laryngoscopy is the gold standard…BUT…
• Still useful technique and important skill to know as EM physician or any kind of emergency first responder
• Requires minimal equipment or training³
• Laryngoscopy requires adequate visualization of the vocal cords or there is a high probability of passing the ETT into the esophagus.
• Therefore, digital intubation is useful in situations with poor visualization of airway (blood, secretions, C-spine, trapped trauma where proper positioning for laryngoscopy is impossible, equipment malfunction, etc)^{1, 2}
• May also be useful in disaster response or mass casualty situations where responders may not have sufficient number of laryngoscopy supplies readily available.

Traditional technique uses an ETT with stylet, syringe, and gloves. Procedure is as follows (Cashwell et al.):

1. Prepare ETT with 6.5-7.5 mm inner diameter
2. With stylet inserted, curve the ETT tube into a “(“ shape
3. Administer RSI or insert a bite block to prevent bite injury
4. Kneel/stand on patient’s left side (if provider is right-hand dominant)
5. Grasp tongue with right hand and gauze. Apply anterior traction to extend tongue from patient’s mouth
6. With volar surface of left hand toward roof of patient’s mouth, insert index and middle fingers of left hand into the back of patient’s pharynx and lift the epiglottis anteriorly to expose glottic opening (Figure 2; from Cashwell et al.)
7. Splay the two fingers on the epiglottis to provide a channel for the ETT
8. Advance the ETT between volar surface of index and middle fingers and the roof of patient’s mouth into the channel between the fingers and advance into the trachea (Fig. 3)
9. Inflate balloon and confirm placement with bilateral auscultation
10. Secure the airway

Sidesaddle Technique

1. Prepare ETT with 6.5-7.5 mm inner diameter
2. Remove stylet if present
3. Administer RSI or insert a bite block to prevent bite injury
4. Kneel/stand at patient’s right side (if operator is right hand dominant)
5. Grasp tongue with left hand and gauze. Apply anterior traction to extend tongue from patient’s mouth
6. With volar surface toward roof of patient’s mouth, insert index and middle fingers of right hand into the back of patient’s pharynx and place middle finger in the center of the epiglottis to lift the epiglottis anteriorly, exposing glottic opening
7. Feed the ETT into the right side of the patient’s mouth above operator’s right thumb and alongside lateral aspect of operator’s right index finger. Use right thumb to stabilize or direct ETT tube as needed to ensure tip of the ETT tube reaches the pad of operator’s right index finger
8. Use the tip of right index finger to gently bend the tip of ETT toward the fingernail of right middle finger (which is still lifting the patient’s epiglottis anteriorly)
9. Feed the ETT into the trachea, allowing it slide in the “V” created by the pad of the right index finger and the fingernail of the right middle finger
10. Inflate balloon and confirm placement with bilateral auscultation
11. Secure the airway

Advantages of the sidesaddle technique invented by Erica Warkus:

• Majority of ETT manipulation is done using the pad of thumb and index finger of the dominant hand, which allow greater tactile sensitivity and maneuverability than using the volar surfaces of the middle and index fingers
• “V” created between the pad of the right index finger and the fingernail of the right middle finger should be centered directly over the glottic opening, which stabilizes the ETT and ensures correct placement
• Once the ETT tube is seated in the “V” of the index and middle fingers, the distal tip of the right index finger can be rested gently against the interaryetenoid notch to ensure that the ETT does not divert into the esophagus
• The right index finger should always be posterior to the ETT tube, further safeguarding against an intraesophageal intubation and soft tissue trauma from ETT tube
• Stylet is not required, therefore reducing the necessary equipment and minimizing the amount of mechanical force applied intraorally, which may be useful in patients with midface trauma or basilar skull fracture
• The epiglottis is lifted using the longest digit, making this technique easier for those with smaller hand sizes
• The sidesaddle technique uses similar biomechanical & ergonomic forces to those that are engaged when holding a ballpoint pen, so the technique may feel more natural than the traditional approach when attempted by first-time operators

Disadvantages

• Manipulation of ETT tube occurs to the left of midline and may slightly increase the risk of bite injury to the hallux if proper bite guard precautions are neglected
• Tonsillar enlargement may interfere with the success rate of the sidesaddle technique, in which case the operator should revert to the traditional digital intubation method

• Because the vocal cords are not physically splayed by the operator’s fingers, there may be an increased risk of vocal cord injury when using the sidesaddle technique in the setting of concurrent laryngeal spasm

References:

1. Cashwell, MJ. Wilcoxen, AC, and Meghoo, CA. 2013. Digital Intubation: the Two-fingered Solution to Securing and Airway. Journal of Special Operations Medicine. 13(3); pp 42-44.
2. Holley J, Jorden R: Airway management in patients with unstable cervical spine fractures. Ann Emerg Med November 1989;18:1237-1239.
3. Stewart RD: Tactile orotracheal intubation. Ann Emerg Med March 1984;13:175-178.

Figure 4. The Sidesaddle Technique

• Figure 4 showing the Sidesaddle Technique created and taught by Erica Warkus, September 2019.

Comparison trial of traditional vs sidesaddle technique (Thursday Conference between lectures and lunch)

1. Give 2 min presentation on the techniques to EM attendings, residents and students. (N ~40)
2. Form two teams with two mannequins per team, one mannequin will have instructions for traditional digital intubation, other will have instructions for sidesaddle digital intubation
3. Run the comparison as a “race” between the two teams to eliminate participant bias between the two techniques
4. Record time to successful intubation (defined as length of time that operator has fingers in mannequin’s mouth on video recording) and # of attempts required for each technique & participant with backup video recording of the tables
5. Also record whether participant has been taught digital intubation, performed digital intubation and years of experience in EM

Estimated length of time (30 min)