Nebulization Versus Spray-as-You-Go Airway Topical Anesthesia Using Dexmedetomidine and Lidocaine Mixture During Awake Flexible Fiberoptic Intubation in Temporomandibular Ankylosis

Nebulization Versus Spray-as-You-Go Airway Topical Anesthesia Using Dexmedetomidine and Lidocaine Mixture During Awake Flexible Fiberoptic Intubation in Temporomandibular Ankylosis: A Randomized Double-Blind Trial

The aim of this study is to compare the efficacy of airway topical anesthesia with nebulization to the spray-as-you-go technique using dexmedetomidine and lidocaine mixture to achieve upper airway anesthesia in TMJ ankylosis patients.

Awake fiber-optic intubation (AFOI) has become the accepted gold standard technique for management of recognized difficult airway as the larynx remains in a posterior position and the patient is able to protect the airway from soiling and can maintain the airway patency as well as spontaneous breathing efforts. Awake intubation requires that the patient remains calm and cooperative and is provided with sufficient anxiolysis, analgesia, and topical anesthesia without compromising the airway.

Gag reflex, cough, and laryngospasm can be upsetting during the process. Awake patients never permit airway instrumentation without airway anesthesia. Therefore, effective airway anesthesia is required for airway instrumentation and patient comfort.

For awake intubation, topical airway anesthesia can be provided either by using fiberoptic bronchoscope (FOB) to apply local anaesethic to the airway by a "spray-as-you-go" technique or nebulizing the patient for about 10-15 min.

Inclusion Criteria:

• Age from 21to 65 years.
• Both sexes.
• American Society of Anesthesiologists (ASA) physical status I or II and scheduled for elective surgery requiring general anesthesia , and known to have Temporomandibular joint ankylosis and expected to be difficult intubation patient due to restriction of jaw mobility and limited mouth opening less than 2 fingers.

Exclusion Criteria:

• History of allergy to dexmedetomidine or lidocaine.
• History of drug abuse.
• Concomitant use of medications which may exaggerate the heart rate (HR) response of -dexmedetomidine (e.g. digoxin or β-adrenergic antagonists), HR <50 beats/min, systolic blood pressure (SBP) <90 mmHg.
• Pregnancy.
• Morbid obesity( BMI more than 35).
• Patients on anticoagulants, nasal trauma, deformity or polyp, CSF rhinorrhea, fracture base skull.
• Cardiac and/or respiratory disease, reactive airway disease, hepatic or renal disorders.