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From the Department of Anaesthesiology, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India.
Address correspondence and reprint requests to Anil Agarwal, MD, Type IV/48, SGPGIMS, Lucknow 226 014, India. Address e-mail to aagarwal{at}sgpgi.ac.in.
Abstract
Postoperative sore throat (POST), although a minor complication, remains a source of postoperative morbidity. We compared the efficacy of dispersible aspirin gargle to benzydamine hydrochloride (a topical nonsteroidal anti inflammatory drug) gargles for prevention of POST. We enrolled 60 consecutive female patients, 16–60 yr of age, ASA physical status I or II, undergoing elective modified radical mastectomy under general anesthesia in this prospective, randomized, placebo-controlled, single-blind study. Patients were randomly divided into 3 groups of 20 subjects each: Group 1 (C) mineral water; Group 2 (AS) tab aspirin 350 mg; and Group 3 (BH) 15 mL of benzydamine hydrochloride (0.15%). All the medications were made into 30 mL of solution. Patients were asked to gargle this mixture for 30 s, 5 min before induction of anesthesia. Grading of POST was done at 0, 2, 4, and 24 h postoperatively on a 4-point scale (0–3). Aspirin gargles reduced the incidence of POST for 4 h whereas benzydamine hydrochloride gargles reduced POST for 24 h. POST was more severe in the control group at 0 and 2 h (P < 0.05). Aspirin and benzydamine hydrochloride gargles significantly reduced the incidence and severity of POST (P < 0.05).
Although a minor complication, postoperative sore throat (POST) contributes to postoperative morbidity and patient dissatisfaction. The incidence of POST varies from 40%–100% in intubated patients (1–3). POST had been rated by patients as the 8th most undesirable outcome in the postoperative period (4). Numerous nonpharmacological and pharmacological measures have been used for attenuating POST with variable success. Among the nonpharmacological methods, smaller sized endotracheal tubes, lubricating the endotracheal tube with water soluble jelly, careful airway instrumentation, intubation after full relaxation, gentle oropharyngeal suctioning, minimizing intracuff pressure, and extubation when the tracheal tube cuff is fully deflated have been reported to decrease the incidence of POST (2). Pharmacological measures, including beclomethasone inhalation and gargling with azulene sulfonate, have been reported to decrease the incidence of POST (5,6). Tenoxicam (hydrophilic nonsteroidal antiinflammatory drug [NSAID]) from an impregnated gauze pack has been shown to be effective in reducing moderate or severe POST (7). Aspirin gargles are reportedly effective in relieving pain of oral lesions (8), but the efficacy of aspirin for preventing POST has not been evaluated. Preemptive topical benzydamine hydrochloride (BH) has been reported to decrease the incidence of sore throat resulting from laryngeal mask airway use (9). The present study was therefore planned to compare the efficacy of aspirin and BH (another topical NSAID) gargles, for prevention of POST after oral endotracheal intubation.
METHODS
After obtaining ethical clearance from our institute's ethical committee and informed written patient consent, 60 consecutive adults (16–60 yr), females, ASA physical status I–II, undergoing elective modified radical mastectomy under general anesthesia were enrolled in this prospective, randomized, placebo-controlled, single-blind study. Patients with a history of preoperative sore throat, more than one attempt at intubation, Mallampati grade >2, known allergies to aspirin or BH and patients with recent NSAID medication were excluded from the study.
Presuming that therapy would reduce the incidence of POST by 50%; power analysis, with 
= 0.05, ß = 0.90, showed that we would need to enroll 19 patients in each group. On this basis we chose to enroll 20 patients in each group.
Patients were randomized into 3 groups of 20 subjects each with the help of a computer-generated table of random numbers: Group 1 (C): mineral water; Group 2 (AS): tab aspirin 350 mg; Group 3 (BH): 15 mL of benzydamine hydrochloride (0.15%). Depending upon the results of the randomization, all the medications were made into 30 mL with distilled water, which was placed into an opaque container by a staff nurse who also asked patients to gargle this mixture for 30 s after their arrival in the operation room. This nurse was not involved in the subsequent management of these patients. Induction of anesthesia was commenced 5 min later. Patients could not be blinded because of the different tastes of the mixtures.
The patients were premedicated with oral lorazepam 0.04 mg/kg the night before and 2 h before the induction of anesthesia, administered with sips of water. Anesthesia was induced with fentanyl 3 µg/kg and propofol 2 mg/kg. Tracheal intubation was facilitated by vecuronium bromide 0.1 mg/kg, and the trachea was intubated with a soft seal cuffed sterile polyvinyl chloride endotracheal tube (Portex Limited, CT 21, 6JL, UK) 7 mm inner diameter. The endotracheal tubes were lubricated with sterile water-soluble jelly (Lubic®; Neon laboratories Limited, Mumbai, India). The cuff was inflated with air and cuff pressure was maintained between 18–22 cm of water with the use of a pressure monitoring transducer (Edward Life Sciences LIC, Irvine, CA). This pressure transducer was connected to the pilot balloon of the endotracheal tube, which then provided a continuous digital display of the intracuff pressure on the screen of the monitor. Heat and moisture exchangers were used in the gas delivery circuit in all cases. Laryngoscopy and endotracheal intubation were performed by an anesthesia registrar (SSN) who was blinded as to the group allocation. Anesthesia was maintained using 70% nitrous oxide in oxygen and a propofol infusion 50–150 µg kg–1min–1 and intermittent fentanyl and vecuronium as required. Monitoring consisted of 5-lead electrocardiography, noninvasive arterial blood pressure, pulse oximetry, nasopharyngeal temperature, and ETco2, which was kept between 30 and 35 mm Hg. At the end of surgery, the muscle relaxation was reversed by a combination of neostigmine 0.05 mg/kg and glycopyrrolate 0.01 mg/kg. After gentle suctioning of oral secretions by a 12F suction catheter, patients were tracheally extubated and transferred to the postanesthesia care unit. Patients received fentanyl for their postoperative pain via IV patient-controlled analgesia. At arrival of patients in the postanesthesia care unit (0 h) and thereafter at 2, 4, and 24 h, POST was assessed by another anesthesiologist (SD) who was unaware of the group allocation. POST was graded on a 4-point scale (0–3): 0 = no sore throat, 1 = mild sore throat (complains of sore throat only on asking), 2 = moderate sore throat (complains of sore throat on his/her own), and 3 = severe sore throat (change of voice or hoarseness, associated with throat pain). Side effects, if any, were also noted.
Differences in the age and weight among the groups were compared by one-way analysis of variance. Differences in the incidence of POST among the groups were compared with the help of test of proportions for large sample (Z test). Severity of POST was analyzed by Fisher's exact test. SPSS 9.0 (SPSS Inc, Chicago, IL) was used for statistical analysis. P < 0.05 was considered as significant.
RESULTS
Fifty-eight patients completed the study. Two patients (1 each from the groups AS and BH) could not gargle properly and were therefore excluded. There was no difference among the groups in age, height, weight, and duration of surgery (Table 1) (P > 0.05).
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The incidence of POST was more frequent in group C compared with group BH at all time points (P < 0.05) (Fig. 1). A significantly more frequent incidence of POST was observed in group C only at 0 and 2 h when compared with group AS (P < 0.05) (Fig. 1). No difference in the incidence of POST was observed between the AS and BH groups at any time (P > 0.05).
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Significantly more patients suffered severe POST in group C at 0 and 2 h when compared with the other 2 groups (P < 0.05) (Table 2). The severity of POST was similar between groups AS and BH at all times (P > 0.05). Aspirin and BH gargles were well tolerated by most patients, except 2 patients in the BH group who complained of numbing of the mouth and dysgeusia (distorted sense of taste).
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Absolute and relative risk reduction in group AS were 0.59 and 74% and the number-needed-to-treat was 2. Absolute and relative risk reduction in group BH was 0.54 and 68% and the number-needed-to-treat was 2.
DISCUSSION
The result of this study demonstrated that preoperative gargling with aspirin reduced the incidence of POST for up to 2 hours, whereas BH gargles reduced the incidence of POST up to 24 hours. More patients reported severe POST in the control group when compared with the other 2 groups.
POST may be caused by pharyngeal, laryngeal, or tracheal irritation and may occur even in the absence of endotracheal intubation (10). It is difficult to differentiate whether POST is secondary to laryngoscopy alone, is caused by insertion of an endotracheal tube, or is a combined effect of the two (1).
BH is a topical NSAID that has analgesic, local anesthetic, antiinflammatory and antimicrobial properties with a terminal half-life of approximately 8 hours (11). These actions of BH may be mediated by the prostaglandin system (12). BH has been used for prevention of radiation-induced mucositis in the oral cavity, as well as for treatment of several oral disorders. Although local drug concentrations are relatively large, the systemic absorption of mouthwash-gargle, vaginal and rectal doses of benzydamine is relatively low compared to oral doses: this lower absorption should greatly diminish the potential for any systemic drug side effects when BH is administered by these routes (13).
Aspirin is a NSAID analgesic that is rapidly converted in the body to salicylic acid with a t
of the antiinflammatory dose being 8–12 hours (14). Aspirin gargle has been reported to be effective for relieving pain of oral lesions (8).
In conclusion, we observed that gargling with aspirin and BH preoperatively reduced the incidence and severity of POST. Aspirin gargle was effective for reducing POST for 2 hours whereas BH gargle was effective for 24 hours. Both aspirin and BH gargles are safe, simple and effective means of reducing the incidence and severity of POST.
Footnotes
Accepted for publication May 26, 2006.
REFERENCES
This article has been cited by other articles:
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  Minerva BMJ, October 7, 2006; 333(7571): 762 - 762. [Full Text] [PDF]
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