Deflated and Inflated Cuff Endotracheal Extubations

The current standard anesthetic practice for extubation is to deflate the endotracheal tube cuff using a syringe prior to extubation. While commonplace and nearly universally accepted, this practice is not based on evidence from randomized controlled trials but is instead due to concern for laryngeal or vocal cord injury and arytenoid cartilage dislocation. However, no publications exist in the medical literature that attribute laryngeal trauma directly to inflated cuff endotracheal tube extubation, as opposed to the process of extubation in general. To the contrary, case reports that describe peri operative extubation with unintentionally inflated cuffs all note the absence of negative outcome.

Alternatively, extubation with an inflated endotracheal tube cuff has been advocated as a technique to reduce airway complications in human and veterinary medicine. Tracheal aspiration, even micro-aspiration by oropharyngeal secretions, may increase the risk of pneumonia and other pulmonary complications. Based on an animal model, inflated cuff extubation may reduce airway contamination by oropharyngeal fluid. Additionally, leaving the endotracheal tube cuff inflated may effectively generate a vital capacity breath during extubation, maximizing oxygen reserves and facilitating a secretion-clearing cough. These theorized advantages may prolong the time to which supplemental oxygen is required as well as decrease airway/respiratory complications in the immediate post-extubation period. Within the intensive care setting, unplanned extubation (including accidental extubation and self-extubation) occurs at a rate of 3% to 16% of intubated patients or 0.1 to 3.6 per 100 days of mechanical ventilation. Estimates of national hospitalizations requiring mechanical ventilation approach 800,000, thereby placing the estimated number of unplanned extubations between 24,000 and 128,000. Presumably, the majority of these unplanned extubations are with inflated cuffs, and yet still no epidemic of laryngeal trauma from inflated cuff extubation exists. Furthermore, there have been no significant differences in laryngeal complications reported between planned and unplanned extubation in the intensive care population, suggesting that it is the endotracheal tube itself (and the process of placing it) that confers the risk of laryngeal complications, rather than the circumstances of its removal.

Though several providers have published their success with inflated cuff extubation, to date no prospective, randomized controlled trial has been performed directly comparing these two techniques. This study proposes to evaluate the effect of inflated cuff extubation on airway contamination by oropharyngeal material, extubation quality, post-extubation oxygenation, and laryngeal symptoms compared to the standard technique of deflated cuff extubation.

To assess the difference in aspiration rates between deflated and inflated cuff extubation, radio-opaque contrast material will be introduced into the oropharynx of intubated patients while under general anesthesia. The presence of this radio-opaque contrast at or below the level of the carina will be assessed with a chest radiograph taken postoperatively.

Inclusion criteria

• Adults aged 18 to 50 years old
• Scheduled for surgery, not of the airway, head, or neck, with anticipated case duration of less than 3 hours
• American Society of Anesthesiologists (ASA) Physical Status Classification of 1 to 3

Exclusion criteria

• Emergent surgery, or surgery requiring prone, sitting or lateral positioning
• Pre-existing laryngeal pathology, obstructive pulmonary disease, pulmonary hypertension, interstitial lung disease, active respiratory infection, recent pneumonia, uncontrolled asthma, or uncontrolled gastroesophageal reflux disease
• Known difficulties with general anesthesia, such as prior anaphylactic reaction, difficult intubation or mask ventilation
• Known allergy to iohexol or a previous severe reaction to any contrast agents
• Unfavorable airway examination, such as Mallampati 4, limited mouth opening, and/or inability to extend neck
• Non-compliance with ASA Practice Guidelines for Preoperative Fasting
• Pregnancy
• Enrollment in another anesthesiology or surgery related interventional research study
• Surgeries scheduled on Friday or a day immediately prior to a holiday