This prospective, randomized, double-blind, two-arm clinical trial will evaluate whether applying 5% lidocaine ointment to endotracheal tubes before intubation reduces airway irritation compared with standard water-based lubricant in adult patients undergoing general anesthesia. The primary objective is to determine whether lidocaine ointment decreases the incidence of coughing or bucking during emergence and extubation. Secondary objectives include evaluating the incidence and severity of postoperative sore throat and hoarseness, as well as intraoperative opioid requirements. Additional demographic and procedural data will be collected to characterize the study population and adjust for potential confounders. The study hypothesis is that 5% lidocaine ointment will reduce emergence coughing and improve postoperative airway comfort without increasing adverse outcomes.

Emergence coughing or bucking is a common complication of general anesthesia with endotracheal intubation and may result in clinically significant increases in hemodynamic stress, airway irritation, postoperative discomfort, and potential complications. Although multiple pharmacologic strategies have been evaluated to reduce emergence coughing, the effectiveness of topical lidocaine preparations applied to the endotracheal tube remains uncertain.

This prospective, randomized, double-blind, two-arm clinical trial will evaluate whether applying 5% lidocaine ointment to the external surface of the endotracheal tube before intubation reduces coughing or bucking during emergence from general anesthesia compared with standard water-based endotracheal tube lubricant.

Adult patients undergoing elective surgical procedures requiring general anesthesia with oral endotracheal intubation will be randomized to receive either 5% lidocaine ointment or standard water-based lubricant applied to the external surface of the endotracheal tube immediately prior to intubation. The study will use standardized anesthetic management, double-blinding procedures, and consistent outcome assessment methods.

The primary outcome is the incidence of coughing or bucking during emergence from anesthesia, assessed from the time anesthetic agents are reduced for extubation until removal of the endotracheal tube. Secondary outcomes include the incidence and severity of postoperative sore throat and hoarseness at defined postoperative time points, as well as total intraoperative opioid administration converted to morphine milligram equivalents.

Additional demographic and procedural information, including age, sex, body mass index, American Society of Anesthesiologists physical status, airway assessment characteristics, duration of intubation, and surgical procedure type, will be collected to describe the study population and evaluate potential factors associated with outcomes.

The study aims to determine whether 5% lidocaine ointment provides a clinically useful strategy for reducing emergence-related airway irritation and improving postoperative airway comfort compared with standard endotracheal tube lubrication.

Inclusion Criteria:

Adults aged 18 years and older, with an upper age limit of 90 years, scheduled for surgery requiring general anesthesia with an oral endotracheal tube.

Patients undergoing general surgical procedures, including but not limited to abdominal surgeries (e.g., hernia repairs, cholecystectomy, appendectomy, bowel surgery), non-cervical spinal surgeries, craniotomies, orthopedic procedures, urologic procedures, and other procedures meeting the inclusion criteria.

American Society of Anesthesiologists (ASA) Physical Status I, II, III, or IV. Patients able to provide informed consent.

Exclusion Criteria:

Age younger than 18 years or older than 90 years. Patients undergoing procedures requiring a specialized airway device instead of a standard oral endotracheal tube (e.g., laryngeal mask airway, double-lumen endobronchial tube).

Patients with known hypersensitivity or allergy to amide local anesthetics. Patients with pre-existing sore throat, upper respiratory infection, or active cough at baseline.

Patients requiring postoperative mechanical ventilation or critically ill patients requiring intensive care.

Patients unable to adequately report outcomes or participate in follow-up assessments.

Current smokers. Pregnant women. Prisoners.

Participants, anesthesia providers, investigators, and outcome assessors will be blinded to treatment assignment. Study ointments will be prepared and dispensed in an identical manner to maintain allocation concealment throughout the study. (If the anesthesia provider applying the lubricant cannot be blinded because of differences in appearance or packaging, then do not check Care Provider.)