Don’t Forget the Routine Endotracheal Tube Cuff Check!

Christina Brown, MD; Laura Cavallone, MD

Letter to the Editor:

To the Editor:

We are writing to call attention to the often under-appreciated importance of checking the endotracheal tube (ETT) prior to the start of the procedure. Routine checks of the ETT integrity and functionality before insertion used to be the standard of care, but the practice is becoming less common, although it is still recommended in current ASA guidelines.1

After induction of anesthesia, a 71-year-old female patient undergoing a parotidectomy was nasally intubated with a TaperGuard 6.5 Nasal RAE tube using a C-MAC® KARL STORZ GmbH & Co. KG Mittelstraße 8, 78532 Tuttlingen, Germany, video-laryngoscope. Intubation was atraumatic and the cuff was inflated with 10 ml of air. After cuff inflation, a persistent significant air leak was noted (> 1 L/min in volume controlled ventilation modality). The integrity of the entire breathing circuit and correct positioning of the ETT between the vocal cords with direct laryngoscopy were confirmed. Although the ETT pilot balloon was noted to be appropriately tense to the touch, a small amount of air was added to the cuff. However, a major air leak persisted. At this point the anesthesiology team decided to proceed with exchanging the ETT, which was successful. The air leak resolved with the new ETT in place and the cuff inflated. Upon closer inspection of the ETT that had been removed from the airway, there appeared to be a defect in which the air injected into the pilot balloon did not reach the cuff (see Figures 1 and 2).

Figure 1

Figure 1. Comparison of normal and defective endotracheal tubes. A) Normal endotracheal tube with 10 ml of air instilled into cuff. B) Defective cuff with 10 ml air instilled into cuff. C) Pressure gauge attached to pilot balloon of normal cuff reading 30 mmHg with cuff inflated. D) Pressure gauge attached to pilot balloon of defective cuff with reading of 30 mmHg with cuff not appropriately inflated.


Figure 2

Figure 2. Comparison of distance traveled by dye instilled into cuff. A) Dye instilled into the normal endotracheal tube travels all the way to the cuff. B) Dye instilled into the defective endotracheal tube stops at the entrance of the pilot balloon tubing into the main tubing (arrow in Figure 2A and 2B).

Air leaks are a common yet critical problem that require quick diagnosis. A systematic approach to evaluation of air leaks is recommended to ensure rapid evaluation and identification of underlying issues. One such approach entails beginning at the patient and following the circuit to the machine. In this case, an air leak was audible from the patient’s oropharynx, which led the team to identify the problem quickly. However, the presence of contradictory findings (tense cuff bulb, holding appropriate inflating pressure in the presence of a major air leak) confounded the diagnostic process, while a preoperative check of the ETT would have unequivocally detected the defect in the cuff tube.

As newer manufacturing techniques have decreased the occurrence of ETT defects, routine assessments of the ETT cuff integrity prior to use have become increasingly less common among providers. The ASA recommends checking all ETT cuffs prior to their use.1 While rare, endotracheal tube cuff defects are a known cause of endotracheal tube leaks which often necessitate endotracheal tube exchange. ETT exchange could pose significant risk to patients especially in the case of the patient with a difficult airway. In our case, had the endotracheal tube been checked prior to the start of the case, the defect could have been easily identified which would have obviated the need for tube exchange.


Christina M. Brown, MD, Resident, Department of Anesthesiology, Washington University in St. Louis, MO.

Laura F. Cavallone, MD, Associate Professor, Department of Anesthesiology, Washington University in St. Louis, MO.

None of the authors have conflicts of interest relating to the publication of this paper.


Reference

  1. Statement on the Standard Practice for Infection Prevention and Control Instruments for Tracheal Intubation. American Society of Anesthesiology, Committee of Origin: Committee on Quality Management and Departmental Administration (QMDA). Approved by the ASA House of Delegates on October 20, 2010, and last amended on October 28, 2015. Retrieved from:
    http://www.asahq.org/~/media/sites/asahq/files/public/resources/standards-guidelines/statement-on-standard-practice-for-infection-prevention-for-tracheal-intubation.pdf.