Deflated and Inflated Cuff Endotracheal Extubations

Overview

General anesthesia is a treatment with medicine to make a patient unconscious for surgery. This is sometimes called "being put to sleep" or "being put under." Most of the time, a breathing tube is used to help a machine breathe for patients. The breathing tube has a cuff, which is like a small balloon. After the breathing tube is placed, the cuff is inflated. This keeps the breathing tube in place and keeps fluids like saliva and stomach juices from getting into the windpipe and lungs. When a breathing tube is removed, that is called extubation. Normally, doctors deflate the cuff before removing the breathing tube. This is called deflated cuff extubation. Some doctors worry that keeping the cuff inflated while it is removed can damage the throat or vocal cords. However, some doctors keep the cuff inflated when removing the breathing tube. This is called inflated cuff extubation. These doctors think that keeping the cuff inflated can help keep fluids from entering the airway. Doctors have not studied if deflated cuff extubation is better or worse than inflated cuff extubation. The goal of this study is to see which type of extubation is better at keeping fluids from getting in the airway. Participants who are part of this study will get general anesthesia and have surgery as planned. Near the end of surgery, a small amount of liquid is placed at the back of a participant's mouth. This liquid is called contrast material, and it is like a dye. The contrast material will help determine if any liquid enters the windpipe or lungs. Then, contrast material is removed, along with any other fluids, using normal methods. When it is safe to take the breathing tube out, a deflated cuff extubation or an inflated cuff extubation will be performed. This decision will be made at random, like by the flip of a coin. Information will be collected about participants, the surgery, and how well a participant is breathing. After surgery, a chest x-ray will be taken to see if any of the contrast material is in the windpipe or lungs. Otherwise, everything else after surgery would be normal. 24 to 48 hours after surgery, a member of the research team will ask about any symptoms a participant may have, like sore throat or a hoarse voice. Research would conclude at that time.

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.