P066: SUPRAGLOTTIC AIRWAY PILOT BALLOON AS A CAUSE OF AIRWAY OBSTRUCTION LEADING TO HYPOXEMIA AND HYPERCARBIA
Joel P Goodman, DO, Steven Freeland, MD, Ana Oviedo, MD, M. Anthony Cometa, MD; University of Florida
Background: Supraglottic airways are helpful & important airway devices within anesthesiology. Advantages of their growing use include reduced airway trauma, ease of use and reduced risk of laryngospasm. Here we describe a complication with the use of a supraglottic airway (SGA) in which the pilot balloon was inadvertently lodged during its placement, leading to an obstruction between the SGA’s aperture and the patient’s glottic opening, resulting in hypoxemia and hypercarbia.
Case: A 50-year-old male presented for repair of a left wrist tendon at our ambulatory surgical center. Baseline vital signs were stable and after an uneventful induction with propofol, bag mask ventilation was easily achieved, followed by atraumatic intubation with an Ambu AuraOnce SGA. Satisfactory placement was confirmed via bilateral breath sounds, equal chest rise and consistent return of end tidal carbon dioxide. Spontaneous ventilation recovered, with tidal volumes in the 300-350 cc range. During the case, he maintained oxygen saturations above 90% with end tidal carbon dioxide levels of 50-55 mmHg. During emergence, the patient had an abrupt decrease in oxygen saturation to 80% with an increase of end tidal carbon dioxide to 61 mmHg, with tidal volumes decreased to 100-200 cc. 100% oxygen was administered and the patient’s breathing was assisted. Despite these efforts, pulse oximetry showed 78%-85%. The head of bed was raised to optimize FRC. On auscultation, wheezing was noted and albuterol was administered. Additional propofol was administered in an attempt to attenuate potential bronchospasm or laryngospasm that may be contributing to the patient’s hypoxemia. No change was seen in oxygenation or ventilation. Jaw thrust maneuver proved ineffective. While searching for other causes of airway obstruction, it was discovered that the pilot balloon was not visible. After careful digital manipulation, it was removed from the intraoral cavity, leading to immediate and marked improvements of oxygenation and ventilation. The patient was extubated and taken to the postanesthesia care unit where he had an uneventful recovery.
Discussion: The paucity of pilot balloon obstruction as a complication to SGA use makes this case a significant one. There is a variety of airway-related complications associated with the use of SGAs including regurgitation & aspiration1 and MRI artifact2, though complication rates are lower compared to endotracheal intubations during general anesthesia3. In our online search, we were unable to find any similarly documented cases of airway obstruction caused by the SGA pilot balloon. Some SGAs come in its manufacture packaging with the pilot balloon stored within the airway aperture, which may be hazardous if not removed. As shown, pilot balloon obstruction may not cause immediate or obvious obstruction during the surgery, but care must be taken to visualize that the pilot balloon is external to the oral cavity after placement of SGA and after patient positioning to avoid migration of the pilot balloon into a potentially obstructing position.
1. BioMed Research International. Volume 2015, Article ID 746560
2. Anaesthesia, Peri-operative medicine, critical care and pain. 2010; 65(6): 569-72.
3. J Oral and Maxillofac Surg. 2010; 68(10): 2359-76