Comparison of Three Different Methods of Attenuating Postoperative Sore Throat, Cough, and Hoarseness of Voice in Patients Undergoing Tracheal Intubation.

CONTEXT: Postoperative sore throat (POST) is a frequent and undesirable complication after general anesthesia with endotracheal intubation. Various pharmacological and non-pharmacological methods with variable success rate are used for attenuating POST. However, no single drug has been universally accepted. AIMS: To compare the effect of betamethasone gel, ketamine gargles and intravenous dexamethasone on the incidence and severity of POST. SETTINGS AND
DESIGN: Prospective randomized controlled single-blinded trial conducted at a tertiary care centre.
MATERIALS AND METHODS: A total of 100 patients of age 18 to 70 yr, ASA class I and II, scheduled for elective surgeries under general anaesthesia were included and divided randomly in betamethasone, dexamethasone, ketamine and control groups. Endotracheal tubes were lubricated with 0.05% betamethasone gel in betamethasone group, 0.2 mg/kg of dexamethasone was administered intravenously before induction of anaesthesia in dexamethasone group, 40 mg of ketamine gargles mixed with 30 ml of saline was given 5 minutes prior to induction in ketamine group. In the control group, none of the above agents were used. During the 24 hr after the operation, we noted the occurrence and severity of POST, cough and hoarseness. STATISTICAL ANALYSIS USED: The demographic data, surgical time and intubation among the groups were analyzed using one-way analysis of variance. Incidence and severity of POST, cough and hoarseness of voice among the groups were analyzed utilizing Chi-square test.
RESULTS: Incidence of POST at one hour was found to be significantly less in betamethasone group (16%) and dexamethasone group (20%) in comparison to the control group (48%). The incidence of POST at 4 hours and 24 hours were found to be comparable. The frequency of hoarseness and cough at 1 hour, 4 hour and 24 hours were similar in all the groups.
CONCLUSIONS: Prophylactic betamethasone gel application and intravenous dexamethasone administration before induction of anaesthesia resulted in clinically important and statistically significant decreases in the incidence of POST only in early postoperative period. Copyright:

INTRODUCTION

Postoperative sore throat (POST) is a minor complication, but it can pose an immense deal of uneasiness in patients.[1] The incidence of POST ranges from 21% to 100% after tracheal intubation,[12] and it is the eighth most common side effect in the postoperative period.[3] Various pharmacological and nonpharmacological methods with variable success rate are used for attenuating POST. Nonpharmacological methods tried were the use of a smaller sized tube, lubrication with water-soluble jelly, and minimizing intracuff pressure.[345] Pharmacological methods used include the application of steroids over the tracheal tube, lozenges, lignocaine, and ketamine gargles.[6789] However, there are only few randomized controlled trials done to compare these pharmacological methods to establish their efficacy and utility.

In this study, we hypothesized that betamethasone lubrication of the tube will be more effective in reducing the incidence of POST than that of other pharmacological methods. To evaluate this, we analyzed the effects of betamethasone gel application on tracheal tube, ketamine gargles, and intravenous dexamethasone on the incidence and severity of POST, cough, and hoarseness of voice after tracheal intubation in patients undergoing general anesthesia.

MATERIALS AND METHODS

This double-blinded, randomized, controlled, clinical trial was approved by the institutional ethical board of our tertiary care hospital. All patients provided written informed consent prior to participation. One hundred patients undergoing tracheal intubation under general anesthesia with the American Society of Anesthesiologists (ASA) I–II status, aged 18–65 years, with a duration of surgery <4 h and scheduled from 2010 to 2011 for elective surgery were included in the study. Patients with oral, neck, and thyroid surgeries, anticipated difficult airway, more than 1 attempt at intubation, preoperative steroid use, and lateral or prone position of surgery were excluded.

Patients were divided into four groups of 25 each by simple randomization using computer-generated random number table: Group B – betamethasone group, Group C – control group, Group D – dexamethasone group, and Group K – ketamine group [Figure 1]. All patients were premedicated with tablet alprazolam 0.25 mg the night before and 2 h prior to surgery. Intraoperatively, monitoring was done with electrocardiogram, pulse oximetry, noninvasive blood pressure, and end-tidal carbon dioxide. Anesthesia was induced with morphine 0.1 mg/kg and propofol 2 mg/kg, and muscle relaxation was achieved with vecuronium 0.1 mg/kg. After 4 min of administration of muscle relaxant, tracheal intubation was done with polyvinyl chloride high–volume, low-pressure cuffed endotracheal tube of size 7.5 mm internal diameter in female patients and 8.5 mm internal diameter in male patients. The tracheal cuff is inflated with room air till no air leak is heard over the trachea with a peak inspiratory pressure of 20 cm water. Cuff pressure was monitored every hour and maintained between 18 and 22 cm water using hand-held pressure gauge. Propofol and nitrous oxide were used for maintenance of anesthesia. In the betamethasone group, 2.5 ml of 0.05% gel was generously applied on the external surface of tracheal tube up to a distance of 15 cm from the tip to cover the entire portion of the tube which comes in contact with the posterior pharyngeal wall, vocal cords, and trachea. In the dexamethasone group, 0.2 mg/kg of dexamethasone was administered intravenously before the induction of anesthesia. In the ketamine group, patients were asked to gargle with 40 mg of ketamine added to 30 ml of saline, over a period of 30 s 5 min prior to induction of anaesthesia. In the control group, none of the above agents were used. Neuromuscular blockade was reversed by neostigmine 0.05 mg/kg and glycopyrrolate 0.01 mg/kg. After ensuring adequate reversal, the patients were extubated and shifted to the postanesthesia care unit. The patients were interviewed for POST, cough, and hoarseness of voice postoperatively at 1, 4, and 24 h after extubation using subjective grading by an anesthesiologist (blinded investigator) who is unaware of the group allocation. The grading was based on 4-point scale (0–3), where Grade 0 = no sore throat; Grade 1 = mild sore throat (complaints of sore throat only on asking); Grade 2 = moderate sore throat (complaints of sore throat on his/her own); and Grade 3 = severe sore throat (change of voice or hoarseness, associated with throat pain). [10]

Figure 1

Consort flow diagram

Statistical analysis

The statistical analysis was done with the help of Statistical Package for Social Sciences (SPSS Inc., Version 15.0 for windows, Chicago, IL, USA). The demographic data, surgical time, and intubation among the groups were analyzed using one-way analysis of variance. The incidence and severity of POST, cough, and hoarseness of voice among the groups were analyzed utilizing Chi-square test. P < 0.05 was considered statistically significant. On the basis of a previous study that showed an incidence of 55.8% for POST, we calculated that 25 patient would be required in each group to detect a difference of 25 % in the incidence with power of 80% and significance level 0.05.[11]

RESULTS

We recruited 25 subjects in each group as per our calculated sample size. The demographic data including age, sex, body weight and ASA status were found to be comparable [Table 1]. Duration of surgery and intubation duration in all the groups were found to be comparable (P = 0.226 and 0.143). The overall incidence as well as the incidence of POST at first hour was found to be significantly less in betamethasone, dexamethasone groups and ketamine than control group (P = 0.015 and P = 0.037). POST at 4 hours and 24 hours were found to be comparable in all groups [Table 2]. The overall incidence as well as the incidence at first hour, fourth hour and twenty-four hours of hoarseness and cough was found to be comparable in all the four groups [Table 3]. The severity of POST, hoarseness, and cough was not significantly different in all the groups [Table 4].

Table 1

Demographic and intraoperative data

Parameters	Control group (n=25)	Betamethasone group (n=25)	Dexamethasone group (n=25)	Ketamine group (n=25)	P
Age (years)	38±4.9	39.6±16	36.9±15	39.7±15.5	0.908
Weight (kg)	60.1±10.3	58.28±9.7	56.60±12.4	57.28±9.5	0.673
Gender (male/female)	12/13	14/11	9/16	10/15	0.497
ASA (I/II)	21/4	22/3	23/2	21/4	0.808
Duration of surgery (min)	120.1±52.2	102.4±45.6	124.2±42.9	131.4±60.7	0.226
Duration of intubation (min)	144.8±53.2	119.1±46.3	145.7±45.6	150.7±62.3	0.143

ASA=American Society of Anesthesiologists

Table 2

Incidence of postoperative sore throat, hoarseness, and cough, n (%)

Symptom	Control group, n (%)	Betamethasone group, n (%)	Dexamethasone group, n (%)	Ketamine group, n (%)	P
POST	12 (48)	4 (16)	5 (20)	6 (24)	0.049
Hoarseness	11 (44)	6 (24)	7 (28)	8 (32)	0.46
Cough	8 (32)	5 (20)	2 (8)	3 (12)	0.128

χ2 test; POST, Betamethasone vs. Control: P=0.015, χ2 test; POST, Dexamethasone vs. Control: P=0.037. POST=Postoperative sore throat

Table 3

Incidence of postoperative sore throat at different times

Evaluation time after extubation (h)	Control group, n (%)	Betamethasone group, n (%)	Dexamethasone group, n (%)	Ketamine group	P
1	12 (48)	4 (16)	5 (20)	6 (24)	0.049
4	9 (36)	2 (8)	3 (12)	6 (24)	0.058
24	4 (16)	1 (4)	0 (0)	3 (12)	0.143

χ2 test; POST at 1 hr, Betamethasone vs. Control: P=0.015, χ2 test; POST at 1 hr, Dexamethasone vs. Control: P=0.037. POST=Postoperative sore throat

Table 4

Severity of POST, hoarseness, cough (n)

Severity	Control	Betamethasone	Dexamethasone	Ketamine	Total	P
POST
Mild	7	3	5	4	19	0.553
Moderate	3	1	0	2	6
Severe	2	0	0	0	2
Hoarseness
Mild	1	3	1	1	6	P=0.072
Moderate	4	3	2	6	15
Severe	6	0	4	1	11
Cough
Mild	5	5	2	1	13	P=0.323
Moderate	2	0	0	2	4
Severe	1	0	0	0	1

DISCUSSION

The study was a prospective randomized double blind study done in hundred patients undergoing tracheal intubation to compare the incidence of POST, hoarseness and cough among groups divided into betamethasone gel application on tracheal tube, ketamine gargles and intravenous dexamethasone. The frequency of POST was observed to be 48% in the control group, which was in equality with the reported incidences in the previous studies.[12] In a study done by CJ Harding, 242 routine surgical patients who had experienced general anesthesia were interrogated regarding POST by either direct or indirect questioning.[12] From 113 patients, 28 patients reported POST on direct questioning, while only 2 out of 129 patients complained POST on indirect questioning (P < 0.001).

The tracheal cuff pressure was monitored every hour and maintained between 18 and 22 cm water in our study. Because cuff pressure increases from 20 cm H2O to 30 cm H2O within minutes, cuff pressure monitoring must be started shortly after tracheal intubation when nitrous oxide is used.[13] The incidence of POST and hoarseness of voice was found to be maximum in the 1st h after extubation. They diminished in the 4th h and were found to further reduced at 24 h after extubation in all the groups. In the control group, the rate of POST was 48%, 36%, and 16% at 1, 4, and 24 h, respectively, on postextubation. The occurrence of hoarseness was 44%, 36%, and 28% at 1, 4, and 24 h separately. The incidence of postoperative cough remained almost the same in the 20-h follow-up period. It was 28% at 1st h, 24% in the 4th h, and 28% again at 24 h. This demonstrated that POST, hoarseness, and cough stayed uncertain in few patients even 24 h later.

The incidence of POST was significantly less in betamethasone group in our study. This study confirms the findings of Sumathi et al.[2] They compared betamethasone gel (0.05%) and lignocaine jelly with the control group. The rate of POST, cough, and hoarseness of voice was essentially lower in the betamethasone group compared to other two groups postoperatively. Our study affirms the findings by Ayoub et al.[11] and Selvaraj et al.[14] demonstrating that the use of betamethasone gel significantly reduces the incidence of POST, cough, and hoarseness of voice. Although Stride[15] inferred that 1% hydrocortisone water-soluble cream was ineffectual in lessoning the incidence of POST, it was later on analyzed that they had applied topical hydrocortisone only from the distal tip to 5 cm above the cuff. The advantageous impact of steroid gel application was seen in consequent studies because of the widespread application of steroid gel from the tip of the tube to 15 cm above the cuff.

Another finding was that dexamethasone likewise diminished the occurrence of POST significantly. The observations are similar to the study done by Thomas et al.[16] and Park et al.[7] Thomas et al. observed that 20% of patients in the dexamethasone (2 mg/kg IV) group had postoperative sore throat, contrast to 56.3% patients in the control group. In addition, the severity of sore throat at 1, 3, 6, 12, and 24 h was reduced in the dexamethasone group compared to the control group. Zhao et al.[17] performed meta-analysis that recommended intravenous dexamethasone could decrease the incidence of POST both at 1 and at 24 h postextubation. Moreover, the study demonstrated that prophylactic dexamethasone reduced the frequency of POST at 1 h but not at 24 h postextubation.

The incidence of POST in the ketamine group was similar to that of control group. Canbay et al.[18] detailed a reduction in POST from 78% to 40% after ketamine gargles in patients undergoing septorhinoplasty operation under general anesthesia. Chan et al.[19] also demonstrated that gargling with ketamine effectively decreased POST, with no adverse reactions, but the effect was not found at 24 h after extubation. The limitations of the use of gargles are that they could not be performed in a double-blinded manner. At times, patients might find discomfort in performing gargles in the operation room. Ketamine gargle is also difficult to perform in uncooperative patients and children. The taste of ketamine gargle was also not tolerated by patients well. The incidence of hoarseness of voice and cough was found to be comparable in all the four groups at different times. Few studies done previously showed that hoarseness and cough were also significantly reduced by betamethasone and dexamethasone. The incidence of hoarseness of voice and cough in the postoperative period in the control group was 44% and 32%, respectively.

Of 100 patients, 2 patients had severe POST, 11 patients had severe hoarseness, and 1 patient had severe cough. The severity of POST, cough, and hoarseness was similar among all the groups.

Taking everything into account, POST, hoarseness of voice, and cough are basic problems in intubated patients. Prophylactic betamethasone gel application over the tracheal tube and intravenous dexamethasone are both effective techniques for ameliorating POST following tracheal intubation but having no impact on cough and hoarseness.

CONCLUSIONS

Prophylactic betamethasone gel application and intravenous dexamethasone administration before induction of anesthesia resulted in clinically important and statistically significant decreases in the incidence of POST in the immediate postoperative period, but no long-term beneficial effects were found in our study.

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Nil.

Conflicts of interest

There are no conflicts of interest.