Novel Use of Lidocaine/NaHCO3 Mixture within Endotracheal Tube Cuff

In outpatient clinic or operating room settings, anesthesia is an important part of modern oral and maxillofacial surgery.  Measures to decrease bucking, coughing, and hypertension during general endotracheal anesthesia (GETA) emergence attempt to make emergence “smoother.” A smooth emergence and a decreased incidence of postoperative sore throat are very desirable after orbital fracture, complex facial trauma repair and orthognathic surgery.  Bucking and hypertension during emergence from GETA after fracture repair with orbital content manipulation may cause increased hemorrhage and increased intraocular pressure that could negatively affect the patient’s post-operative course.  A smoother emergence can be quite beneficial for patients who are in maxillomandibular fixation (MMF) after mandibular fracture repair or orthognathic surgery.  Managing a troublesome or compromised airway after MMF is more challenging if the patient is coughing from airway irritation.  Sub-optimal conditions may require a release from MMF.

While the endotracheal tube(ETT) cuff can be filled with air, anesthetic vapor, or saline; coated with lubricants, and even sprayed to decrease airway irritation, no method produces this result consistently.   Anesthesiology literature contains a number of studies investigating techniques to decrease airway and hemodynamic disturbances during emergence of an intubated patient.  A mixture of lidocaine and bicarbonate placed inside the ETT cuff has been shown to be more effective in many cases.  Lidocaine is commonly used for its analgesic and anti-arrhythmic properties, and more recently, it’s anti–inflammatory properties.  When combined with bicarbonate, diffusion of the mixture through the ETT cuff to the tracheal tissues, and also systemically, contributes to a smoother emergence, decreased bucking, decreased hypertension, and a lower incidence of postoperative sore throat. This technique has not been reported in the oral and maxillofacial surgery literature to date and its potential merits are worthy of discussion.

In the operative suite, a 1:1 mixture of 2% lidocaine with 8.4% sodium bicarbonate was used to expand the cuff after which the ET position was verified and secured.  The volume delivered for an adequate seal was accomplished by administering 8-10 ml of the mixture through the ETT pilot balloon.  The syringe remained connected to the pilot balloon until the plunger retreated and was found to be at rest.  An additional 1 ml was placed into the cuff at this point, and the syringe was detached from the pilot balloon.

Upon surgical case completion during emergence, patient stimulation was evaluated through visual observation with vital signs also being qualitatively evaluated. Objective analysis was then performed on the data to determine effectiveness of the proposed lidocaine/ bicarbonate mixture.

Retrospective review of patients undergoing Surgery at Vanderbilt University Medical Center concludes that lidocaine and bicarbonate in the endotracheal tube cuff contributes significantly to a smoother emergence, which is consistent with the findings in the anesthesiology literature. Minimal bucking and coughing and decreased blood pressure variability were observed during emergence.   Postoperative complaints of sore throat were also reduced. Using a lidocaine/bicarbonate mixture in the ETT cuff delivers a consistent benefit to patients receiving oral and maxillofacial surgery, especially in instances where maxillomandibular fixation is necessary.

References:

Cassuto J, Sinclair R, Bonderovic M. Anti-inflammatory properties of local anesthetics and their present and potential clinical implications. Acta Anaesthesiologica Scandinavica. 2006;50(3):265-282.

Estebe JP, Dollo G, Le Corre P, Le Naoures A, Chevanne F, Le Verge R, et al. Alkalinization of intracuff lidocaine improves endotracheal tube-induced emergence phenomena. Anesthesia & Analgesia. 2002;94(1):227.