Evaluating the Effectiveness of Intracuff Dexmedetomidine Versus Alkalinized Lidocaine in Preventing Postoperative Sore Throat Following Prolonged Prone Surgery
Phase: PHASE2
Conditions: Sore Throat
Sponsor: Prince Sultan Military Medical City

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Evaluating the Effectiveness of Intracuff Dexmedetomidine versus alkalinized lidocaine in 
Preventing Postoperative Sore Throat Following Prolonged Prone Surgery. 
 
 
 
 
IRB: HP-01-R079 
 
 
 
 
Date: 15/04/2025 
 
 
 
 
 
 
 
 
 
 
 

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Introduction: 
Tracheal intubation is performed under general anesthesia to secure the airway and is often 
associated with varying degrees of trauma. One of the most common consequences of intubation 
is postoperative sore throat (POST), which affects approximately 30% to 65% of patients. 
Additionally, hoarseness of voice occurs in about 16% to 55% of cases (1,2). POST is considered 
one of the most undesirable outcomes of the postoperative period, as it significantly negatively 
impacts the overall surgical experience and the hospital stay. It can adversely affect patient 
satisfaction and daily activities even after discharge from the hospital (2).  
POST is caused by various factors, including vocal cord damage, nerve compression, congestive 
blood loss, and injury to the epithelium and mucosal cells resulting from airway secretions and 
prolonged anesthesia (3). 
Recently, studies have indicated that several factors contribute to POST, including the shape of 
tracheal tubes, cuff size, cuff pressure, duration of tube placement, number of suctioning 
attempts, the time and manipulations required for tube insertion, and the use of inhalation 
anesthesia (3). 
The position change from supine to prone can make a change in endotracheal tube (ETT) cuff 
pressure and endotracheal tube displacement. The change in cuff pressure and tube displacement 
can affect the incidence of POST, hoarseness, and cough (4,5). The improper placement of a 
patient in prone position caused the neck muscles to cramp, put pressure on the vocal cords 
causing hoarseness (6). 
To decrease the incidence of POST, various interventions can be implemented. Among non-
pharmacological approaches, choosing the appropriate tracheal tube size is critical for 
minimizing POST and ensuring effective airway management during intubation. The 

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recommended sizes are 6.0 to 7.5 mm for females and 7.0 to 8.0 mm for males. Excessive cuff 
pressure can cause mucosal trauma and pressure-related injuries, thereby raising the likelihood of 
developing POST. To reduce these effects, a prospective randomized controlled trial found that 
maintaining cuff pressure at 20-25 mmHg was linked to a lower incidence of POST. Additional 
strategies included using video laryngoscopy during intubation, topically applying non-steroidal 
anti-inflammatory drugs (NSAIDs), administering steroids during surgery, and utilizing various 
gargles (such as magnesium and ketamine) during the procedure (7,8). 
Use of various pharmacological agents have been advocated in the literature to reduce the 
incidence of POST, hoarseness and dysphagia such as the topical administration of nonsteroidal 
anti-inflammatory drugs, lidocaine, steroids and ketamine in various modalities like inhalation, 
nebulization, gargling and Intravenous routes through various mechanisms of action, according 
to systematic reviews (9).  
Intracuff use of saline and lignocaine is recently being reviewed for the effectiveness in 
preventing coughing, POST, and postoperative hoarseness (10). Increasing the alkalinity of the 
local anaesthetic using sodium bicarbonate (NaHCO3) increases the pH of the solution and can 
predictably increase the percentage of the non-ionized fraction of the drug, thus dramatically 
increasing its diffusion through the ETT cuff (11). 
Dexmedetomidine, a selective alpha-2 receptor agonist, is administered for short-term sedation 
with a specificity and an affinity are up to eight times higher than clonidine (12). Recent reports 
revealed that a single dose of gargled Dexmedetomidine (0.5 µg/kg) has the same effect as the 
intravenous administration, on reducing cough rate and postoperative pain score with no 
complications or significant side effects (13). Intratracheal dexmedetomidine given 15 minutes 
prior to end of surgery was more effective at reducing cough reflex, facilitating a smooth 

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extubation, and encouraging a balanced anesthetic recovery more than intratracheal lidocaine 
(14). 
Aim of the work: 
The purpose of the present study will be to evaluate the effectiveness of intracuff dexmedetomidine 
versus alkalinized lidocaine in preventing postoperative sore throat following prolonged prone 
surgery.  
Patients and methods: 
One hundred patients aged between 18 to 75 years, American Society of Anesthesiologists 
(ASA) physical status I and II patients of either sex, undergoing lumbar spine surgery in prone 
position under general anesthesia with endotracheal intubation will be prospectively investigated. 
Patients with a history of recent respiratory tract infection, prior medication with analgesics or 
corticosteroids will be excluded. Other Exclusion criteria will include patients who have 
preoperative sore throat, hoarseness and cough, have a nasogastric tube, patients with 
Mallampati class > 2 and who required more than one attempt for tracheal intubation or patients 
had a duration of tracheal intubation of < 60 min or > 300 min and patients not willing to provide 
their voluntary written informed consent. 
Using a computer-generated random number table, the patients will be randomly allocated into 
Group A, ETT cuff will be filled with dexmedetomidine (n = 50) or Group B, ETT cuff will be 
filled with alkalinized lidocaine (n = 50). An anesthetic nurse, who will not be taking part in 
postoperative patient interview and assessment, will prepare the study solution and ETT. 
In group A, ETT cuff will be filled with 4 ml of dexmedetomidine 4 mcg/ml. While in group B, 
lidocaine 2%, 2 ml will be initially injected into the cuff, and then a supplementary volume of 2 
ml of sodium bicarbonate (NaHCO3) 8.4% will be added to obtain the minimal occlusive 

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volume. Patients will be premeditated with IV glycopyrrolate 0.2 mg and IV midazolam 0.03 
mg/kg. Non-invasive blood pressure, electrocardiography, pulse oximetry, and patient state index 
(PSI) using a sedation monitor (SedLine, Masimo Corp, Irvine, CA 92618) will be applied when 
the patients arrived in the operating room. Anesthesia will be induced with fentanyl 2 μg /kg, 
propofol 2 mg/kg and cisatracurium 0.2 mg/kg. We will ventilate all patients with 100% oxygen 
via a facial mask. We will perform tracheal intubation after confirming adequate muscle 
relaxation (the absence of movement and jaw relaxation). Endotracheal intubation will be 
performed with tubes having an internal diameter of 8.0 Or 7.5 mm for male patients, and 7.5 or 
7.0 mm for female patients.  
One experienced anesthesiologist, blinded of experimental protocol, will perform endotracheal 
intubation and anaesthesia in all patients during the study. Another anesthesiologist, who was not 
blinded to study protocol, though excluded from the data collection, carefully will inflate cuffs in 
all patients. The cuff pressure will be inflated at the minimal occlusive volume i.e., no air leak 
around the tube cuff when positive pressure was administered at 20 cm. of water.  
Patient’s position will be changed from supine to prone for surgery, and patient’s head will be 
positioned on the sponge face pillow without head rotation. After position change from supine to 
prone, we will re-adjust the cuff pressure. Anesthesia will be maintained with 1.5−2.5 vol% 
sevoflurane and 50% in air. The end-tidal CO2 will be kept between 35 and 40 mmHg. The 
depth of anesthesia will be monitored and kept between 25 to 50 (PSI Index). unit. Oral airway 
devices will not be used intraoperatively. Once the surgery is completed and the patient is fully 
awake (with TOF greater than 0.7 and PSI greater than 80), they will be extubated followed by 
gentle oropharyngeal suction. 

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The primary outcome will be the incidence and severity of POST, hoarseness, cough will be 
assessed for 1st, 6th, 12th and 24th hour after extubation. The assessment will be done by the on-
call anesthesiology resident who was blinded of the study group. The severity of POST, 
hoarseness, and cough will be graded using a 4-point scale (0: no, 1: minimal, 2: moderate, 3: 
severe) (Table 1) (15). Any patient will develop post-operative sore throat will be given 
dexamethasone 8 mg IV stat and advised warm normal saline gargles. 
Postoperative visual analog scale scores (0 = no pain to 10 = the most severe pain). Fentanyl will 
be used to alleviate pain of a severity ≥5 on VAS through a bolus of 0.5 µg/kg. Episodes of 
nausea will be also assessed at each time point. Cricoid compression, duration of tracheal 
intubation, duration of prone position, duration of anesthetic time, and incidence of cough during 
extubation will be recorded. 
The secondary objective will focus on monitoring hemodynamic parameters such as blood 
pressure, heart rate, and oxygen saturation. Measurements will be taken at multiple time points, 
including 5 minutes before anesthesia, baseline reading before tracheal intubation, 5 minutes 
post-intubation, every 15 minutes during surgery, and at 2, 12, and 24 hours following the 
procedure. 

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Results and statistics 
The sample size was estimated from preliminary data obtained from 40 patients, And the 
assumption that a 20% reduction in the incidence of POST Would be clinically relevant. 
The Power analysis suggested that a minimum of 44 patients in each group would be needed for 
a β = 0.2, α = 0.05, (adjusted Bonferroni’s p-value). To Compensate for potential dropouts (drop 
Rate = 10%), 50 patients will be enrolled in each group. 
Data were analyzed using SPSS version 16.0 (SPSS Inc, USA) and will be presented as mean 
and standard deviation (SD) or frequencies (%). A parametric test (independent sample t-test) 
will be used for determining any difference between the means of two groups for a particular 

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variable. Repeated measures analysis of variance (ANOVA) will be used to determine any 
difference in the basic monitoring profile and amount of drug required at different time intervals 
of individuals in both groups. A p-value <0.05 will be considered as statistically significant, and 
a p-value <0.001 as highly significant.  
Discussion  
The data obtained will be compared with similar study. 
  
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