J. Brimacombe, 1 L. Holyoake, 2 C. Keller, 3 J. Barry, 4 D. Mecklem, 4 A. Blinco 5 and K. Weidmann 5

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1 Emergence characteristics and postoperative laryngopharyngeal morbidity with the laryngeal mask airway: a comparison of high versus low initial cuff volume J. Brimacombe, 1 L. Holyoake, 2 C. Keller, 3 J. Barry, 4 D. Mecklem, 4 A. Blinco 5 and K. Weidmann 5 1 Clinical Professor, 2 Research Assistant, 4 Consultant, 5 Resident, Department of Anaesthesia and Intensive Care, Cairns Base Hospital, Australia 3 Consultant Anaesthetist, Department of Anaesthesia and Intensive Care Medicine, Leopold-Franzens University, 6020, Innsbruck, Austria Summary In this study we tested the hypothesis that the initial cuff volume of the laryngeal mask airway in uences emergence characteristics and postoperative laryngopharyngeal morbidity. One hundred and sixty adult patients undergoing minor surgery were randomly assigned for airway management with the laryngeal mask airway with either a fully in ated cuff (LMA-High) or a semi-in ated cuff (LMA-Low). Anaesthesia was with propofol, nitrous oxide, oxygen and iso urane. Following insertion, the cuff was in ated with either 15 or 30 ml for the size 4 (females) and 20 or 40 ml for the size 5 (males). At the end of surgery, a blinded observer documented the presence or absence of adverse airway events (hypoxia, hypercapnea, coughing, retching, regurgitation/vomiting, airway obstruction, hypoventilation, hiccupping, biting, body movement or shivering) during every 1 min epoch and cardiorespiratory variables (heart rate, mean blood pressure, arterial oxygen saturation, end-tidal carbon dioxide and respiratory rate) every 5 min until the patient was awake and the laryngeal mask airway removed. Patients were interviewed about pharyngolaryngeal morbidity (sore throat, dysphonia and dysphagia) immediately before leaving the postanaesthesia care unit and 18±24 h following surgery. Analysis by epoch showed more partial airway obstruction in the LMA-High group, but analysis by patient numbers revealed no difference. Heart rate was slightly higher in the LMA-High group upon arrival in the postanaesthesia care unit, but otherwise there were no differences in cardiorespiratory responses. Sore throat and dysphagia were more common in the LMA-High group. We conclude that, in general, emergence characteristics with the laryngeal mask airway are not in uenced by the volume of air used to in ate the cuff, but that postoperative sore throat and dysphagia are more likely at high initial cuff volumes. Keywords Complications: hypoxia, airway obstruction, coughing, sore throat, dysphagia. Laryngeal mask airway: cuff pressure.... Correspondence to: Dr J. Brimacombe Accepted: 3 November 1999 Routine in ation of the laryngeal mask airway (LMA) cuff to the maximum suggested volume is not recommended by the manufacturer [1] but is common practice, as illustrated in several trials [2±5]. It has been shown that the optimal functional seal is usually obtained at submaximal cuff volumes [6, 7], but there are no data comparing complications during emergence at high and low cuff volumes and there are con icting data about the in uence of cuff pressure and volume on pharyngolaryngeal morbidity [8, 9]. In this study, we tested the hypothesis that initial LMA cuff volume in uences airway complications and cardiorespiratory responses during emergence and postoperative pharyngolaryngeal morbidity. 338 Q 2000 Blackwell Science Ltd

2 J. Brimacombe et al. Emergence with the laryngeal mask airway Methods One hundred and sixty patients (ASA physical status I±III, aged 18±80 years), scheduled to undergo general anaesthesia with the LMA, were randomly assigned by sealed envelope to have the cuff either fully (LMA-High) or semi-in ated (LMA-Low) following insertion. Patients were not studied if they required surgery to the head and neck or in the prone position, or had jaw, neck, mouth or upper respiratory tract symptoms in the previous 10 days. Ethics Committee approval and written informed consent were obtained. A standard anaesthetic protocol was followed and routine monitoring applied. Midazolam 0.02±0.03 mg.kg 1 and fentanyl 0.5±1.0 mg.kg 1 were administered. Anaesthesia was induced with propofol 2± 3 mg.kg 1 and maintained with oxygen 33% in nitrous oxide and 0.5±2% iso urane. After loss of eyelash re ex, patients' lungs were manually ventilated via a facemask without the use of an oral airway. Approximately 1 min later, the LMA was inserted and xed according to the manufacturer's instructions [1] by anaesthetists with at least 6 months' clinical experience and more than 100 LMA insertions. A clear, water-based lubricant (K-Y Lubricating Jelly, Johnson and Johnson, Maidenhead, UK) was applied to the dorsal surface of the LMA before insertion. A size 4 LMA was used for females and a size 5 LMA for males [10]. The cuff was in ated with the randomised volume of air (size 4, 30 or 15 ml; size 5, 40 or 20 ml) and connected to a circle anaesthesia breathing system. The pilot balloon was concealed within a gauze swab for the purposes of blinding. A 5-cm long translucent polyvinylchloride bite block [11] was used with the LMA. Ease of airway management was graded by the anaesthetist as easy (one attempt, no tactile resistance), some dif culty (one attempt, some tactile resistance) and dif cult (two attempts). A failed attempt with the LMA was de ned as removal of the device from the mouth. If LMA insertion was unsuccessful after two attempts, the patient was withdrawn from the study and the case repeated. A heat and moisture exchanger was attached to the proximal end of the LMA. Patients underwent manually assisted breathing until spontaneous breathing resumed. Intraoperative analgesia was with morphine (1±2 mg increments, as needed); intravenous uids (Hartmann's solution) were given intra-operatively as required. At the end of surgery, anaesthesia was maintained at $ 1 minimum alveolar concentration (MAC) iso urane with 100% oxygen and the patient was moved onto a bed. The following data were collected immediately before transfer to the postanaesthesia care unit (PACU): MAC, arterial oxygen saturation (S p O 2 ) end-tidal carbon dioxide (ETCO 2 ), respiratory rate, heart rate and mean arterial pressure. Anaesthesia was discontinued and the patient transferred to the PACU (a distance of 10 m with a transfer time of less than 30 s). Nurses who had undergone standard training in LMA removal [12] and had experience of at least 100 LMA removals managed patients in the PACU. In the PACU, supplementary oxygen at 4 l.min 1 was given via a T-bag [13] that was attached to the proximal end of the heat and moisture exchanger. During emergence, a single trained observer (L.H.), who was blinded to the volume of air in the cuff, documented adverse airway events and collected cardiorespiratory data. Data collection commenced less than 30 s after anaesthesia was discontinued and immediately upon arrival in the PACU. If any adverse events occurred, they were timed, an explanation was given and any interventions noted. Adverse airway events were de ned as: hypoxia (S p O 2 < 90%), hypercapnea (F E 0CO 2 $ 70 mmhg), coughing, retching, regurgitation/vomiting, complete airway obstruction (good respiratory effort but no air movement), partial airway obstruction (good respiratory effort with noisy breathing), hypoventilation (poor respiratory effort with respiratory rate < 6 breath.min 1 ) hiccupping, biting, body movement and shivering. The number of 1-min epochs in which the adverse event occurred was recorded. Heart rate, S p O 2, mean arterial pressure, respiratory rate and F E 0CO 2 were documented every 5 min for 20 min. The LMA was removed when the patient was able to open their mouth to command. The cuff was not de ated for removal. Any coughing at removal and any blood on the LMA were documented. Before discharge to the ward, the oral cavity of all patients was assessed for trauma to the lips, teeth and tongue. Pharyngeal suction was not performed. Postoperative analgesia in the PACU unit was with morphine given intravenously in 1±2 mg increments. Postoperative analgesia on the ward was with intramuscular morphine and/or oral paracetamol. The following additional intra-operative data were collected by the anaesthetist: dose of anaesthesia drugs, dose of morphine, anaesthesia time (injection of propofol until volatile agent switched off) and use of local anaesthesia. The following additional data were collected in the PACU: emergence time (volatile agent switched off to LMA removal) and dose of morphine and use of iv uids. Patients underwent two unblinded structured interviews (by LH) postoperatively: (i) before leaving the PACU (early) and (ii) 18±24 h (late) following surgery. Patients were unaware of the airway device used. At interview, patients were asked whether they had any of the following symptoms: sore throat (constant pain, independent of swallowing), sore neck, sore jaw, dysphonia (dif culty speaking and pain on speaking) and dysphagia (dif culty or pain provoked by swallowing), any symptoms were graded by the patient as mild, moderate or severe. Q 2000 Blackwell Science Ltd 339

3 J. Brimacombe et al. Emergence with the laryngeal mask airway The sample size (n ˆ 80) was selected to detect a projected difference of 5% between the groups for a type I error of 0.05 and a power of 0.9 with respect to coughing during emergence [4]. The distribution of data was determined using Kolmogorov±Smirnov analysis. Statistical analysis between the groups was with paired t-test with Bonferroni adjusted probability. Intragroup comparisons were made with a one-way analysis of variance. Adverse events were analysed by the number of 1-min epochs and by the number of patients in whom they occurred. Signi cance was taken as p < Results There were no differences between groups for patient characteristics or surgical or anaesthetic details (Table 1). Analysis by epoch showed more partial airway obstruction in the LMA-High group, but the incidences of other adverse events were similar (Table 2). Analysis by patient numbers revealed no difference between groups. Two patients in each group required a brief increase in oxygen ow. There were no differences in cardiorespiratory responses or adverse events between the groups (Tables 3 and 4). Early and late sore throat and dysphagia were more common in the LMA-High group (Table 5). Discussion Our data show that emergence characteristics are generally unin uenced by initial cuff volume. Partial airway obstruction occurred more frequently in the LMA-High group, but only in terms of epochs and not patients. The heart rate was slightly higher in the LMA-High group on arrival in the PACU, but the differences were small and of doubtful clinical signi cance. The frequency of problems during emergence with the LMA has been reported by two groups [4, 14]. Gataure et al. [4] reported a 54% incidence of complications, but this included excess salivation, which we did not consider to be a complication. Nunez et al. [14] reported a 3% incidence of complications during emergence and a 21% incidence of coughing during LMA removal. It is interesting that Gataure et al. LMA-High LMA-Low (n ˆ 80) (n ˆ 80) p* Age; years [range] 41 [18±79] 43 [18±78] NS Height; cm [range] 173 [155±196] 172 [150±196] NS Weight; kg [range] 74 [46±120] 73 [50±104] NS Male: Female 49 : : 31 NS Smokers 31 [39%] 36 [45%] NS Procedures: General 12 [15%] 14 [17%] NS Gynaecological 14 [17%] 14 [17%] NS Urological 9 [11%] 8 [10%] NS Plastic 2 [2%] 5 [6%] NS Orthopaedic 43 [54%] 39 [49%] NS Anaesthesia drugs: Propofol; mg 206 (65) 201 (73) NS Fentanyl; mg 99 (26) 93 (29) NS Midazolam; mg 2.6 (1.3) 2.0 (0.8) NS Morphine; mg 3 [0±15] 3 [0±20] NS Local In ltration 28 [35%] 33 [41%] NS Intravenous uids 40 [50%] 49 [61%] NS Anaesthesia time; min 45 (34) 52 (40) NS Emergence time; min 15 (9) 16 (9) NS Airway management grade:² Easy 62 [78%] 61 [76%] Some dif culty 13 [16%] 12 [15%] Dif cult 5 [6%] 7 [9%] Variables at end of anaesthesia: Heart rate; min (14) 68 (13) NS Mean arterial pressure; mmhg 79 (16) 80 (14) NS End-tidal concentration of iso urane; % 1.3 (0.3) 1.2 (0.4) NS Arterial oxygen saturation; % 96.8 (2.4) 97.1 (1.8) NS Respiratory rate; min (5) 17 (6) NS End-tidal tension of carbon dioxide; mmhg 52 (10) 53 (10) NS Table 1 Patient, surgical and anaesthetic characteristics for the high (LMA-High) and low (LMA-Low) cuff volume groups. Values are mean (SD), mean [range] or number [proportion] * NS, not signi cant; ²airway management grades: easy [one attempt, no tactile resistance]; some dif culty [LMA, one attempt, some tactile resistance]; and dif cult [two attempts]. 340 Q 2000 Blackwell Science Ltd

4 J. Brimacombe et al. Emergence with the laryngeal mask airway Table 2 Incidence of adverse events during emergence for the high (LMA-High) and low (LMA-Low) cuff volume groups by number of 1-min epochs and by patients. Values are numbers [proportion] Epochs Patients LMA-High LMA-Low LMA-High² LMA-Low³ (n ˆ 1157) (n ˆ 1214) p* (n ˆ 80) (n ˆ 80) p Hypoxia [SpO 2 < 90%] 9 [0.8%] 4 [0.3%] NS 7 [9%] 4 [5%] NS Hypercapnea [F E 0CO 2 > 70 mmhg] 10 [0.8%] 4 [0.3%] NS 3 [4%] 1 [1%] NS Coughing 10 [0.8%] 5 [0.4%] NS 3 [4%] 3 [4%] NS Retching 0 [0%] 1 [0.1%] NS 0 [0%] 1 [1%] NS Regurgitation / vomiting 0 [0%] 0 [0%] NS 0 [0%] 0 [0%] NS Complete airway obstruction 0 [0%] 0 [0%] NS 0 [0%] 0 [0%] NS Partial airway obstruction 28 [2.4%] 8 [0.7%] < [10%] 6 [8%] NS Hiccup 1 [0.1%] 3 [0.3%] NS 1 [1%] 2 [2%] NS Hypoventilation 3 [0.3%] 8 [10%] NS 1 [1%] 3 [4%] NS Biting 12 [1.1%] 13 [1.0%] NS 5 [6%] 5 [6%] NS Body movement 7 [0.6%] 4 [0.3%] NS 6 [7%] 4 [5%] NS Shivering 1 [0.1%] 4 [0.3%] NS 1 [1%] 4 [5%] NS * NS, not signi cant; ²15 patients had one complication, seven patients had two complications and two patients had three complications; ³ 13 patients had one complication, six patients had two complications, one patient had three complications and one patient had ve complications. S p O 2ˆarterial oxygen saturation; F E 0CO 2, end-tidal carbon dioxide concentration. Table 3 Cardiorespiratory data during emergence for the high (LMA-High) and low (LMA-Low) cuff volume groups. Values are mean (SD) Emergence time; min Group S p O 2 ;%* LMA-High 96.6 (2.4) 97.7 (1.9) 98.3 (1.0) 98.4 (1.0) 98.5 (1.0) LMA-Low 96.5 (2.7) 97.9 (2.1) 98.2 (1.6) 98.5 (1.5) 97.9 (1.8) Respiratory rate; min 1 LMA-High 15 (5) 14 (4) 14 (4) 13 (3) 12 (3) LMA-Low 14 (4) 14 (4) 13 (4) 13 (3) 12 (4) F E 0CO 2 ; mmhg² LMA-High 51 (10) 49 (7) 50 (6) 49 (7) 49 (6) LMA-Low 50 (10) 50 (6) 49 (7) 51 (5) 51 (6) Heart rate; min -1 LMA-High 75 (14) 74 (14) 72 (14) 73 (13) 71 (13) LMA-Low 71 (12) 71 (14) 70 (12) 69 (13) 72 (14) Mean arterial pressure; mmhg LMA-High 83 (16) 88 (16) 94 (18) 93 (16) 95 (13) LMA-Low 83 (17) 88 (16) 93 (17) 95 (16) 95 (16) * S p O 2, arterial oxygen saturation; ² F E 0CO 2, end-tidal carbon dioxide concentration. Table 4 Incidence of adverse events during and after removal of the laryngeal mask airway (LMA) for the high (LMA-High) and low (LMA-Low) cuff volume groups. Values are numbers [proportion] LMA-High LMA-Low (n ˆ 80) (n ˆ 80) p* Coughing at removal 2 [2%] 2 [2%] NS Blood detected on LMA 11 [14%] 5 [6%] NS Tongue trauma 0 [0%] 0 [%] NS Lip trauma 0 [0%] 0 [0%] NS Dental trauma 0 [0%] 0 [0%] NS * NS, not signi cant. [4] used the maximum recommended cuff volume and Nunez et al. [14] the minimal volume for an effective seal. However, the mask size used, the timing of removal and the body position during removal were also different between these studies. Our data show that high cuff volume is associated with more laryngopharyngeal morbidity after use of the LMA. This contrasts with the ndings of Rieger et al. [9] who found no differences between an in vivo intracuff pressure of 30 and 180 mmhg, but supports the ndings of Burgard et al. [8] who found that in vivo intracuff pressure limitation to the minimal required for an effective seal reduced the incidence of sore throat. In vivo intracuff pressure increases exponentially with cuff volume. A cuff volume of 15 and Q 2000 Blackwell Science Ltd 341

5 J. Brimacombe et al. Emergence with the laryngeal mask airway Table 5 Incidence of early and late postoperative morbidity for the laryngeal mask airway high (LMA-High) and low (LMA-Low) cuff volume groups. Values are numbers [proportion] LMA-High (n ˆ 80) LMA-Low (n ˆ 80) Severity score² Total Total p* Early: Sore throat 28 [35%] 6 [7%] 0 [0%] 34 [42%] 19 [25%] 2 [3%] 1 [1%] 22 [29%] 0.02 Sore neck 3 [37%] 0 [%] 0 [0%] 3 [4%] 0 [0%] 0 [0%] 0 [0%] 0 [0%] NS Sore jaw 0 [0%] 0 [%] 0 [0%] 0 [0%] 0 [0%] 0 [0%] 0 [0%] 0 [0%] NS Dysphonia 4 [5%] 1 [1%] 0 [0%] 5 [6%] 4 [5%] 0 [0%] 1 [1%] 5 [7%] NS Dysphagia 17 [21%] 3 [4%] 0 [0%] 20 [25%] 8 [14%] 0 [0%] 0 [0%] 8 [11%] 0.01 Late:³ Sore throat 30 [38%] 8 [10%] 3 [4%] 41 [53%] 12 [16%] 2 [3%] 0 [0%] 14 [19%] < Sore neck 3 [4%] 0 [0%] 0 [0%] 3 [4%] 1 [1%] 0 [0%] 0 [0%] 1 [1%] NS Sore jaw 0 [0%] 0 [0%] 0 [0%] 0 [0%] 1 [1%] 0 [0%] 0 [0%] 1 [1%] NS Dysphonia 1 [1%] 2 [2%] 0 [0%] 3 [4%] 1 [1%] 0 [0%] 0 [0%] 1 [1%] NS Dysphagia 11 [14%] 3 [4%] 0 [0%] 14 [18%] 3 [4%] 0 [0%] 0 [0%] 3 [4%] * NS, not signi cant. ² Severity score: 1, mild; 2, moderate; 3, severe. ³ Data incomplete for two patients in the LMA-High group and six patients in the LMA-Low group. 20 ml for females with the size 4 corresponds to a mean in vivo intracuff pressure of 58 and 183 cmh 2 O, respectively [6]. A cuff volume of 20 and 40 ml for males with the size 5 corresponds to a mean in vivo intracuff pressure of 63 and 194 cmh 2 O, respectively [15]. The higher incidence of sore throat at high cuff volumes suggests that the pressure exerted by the LMA cuff against the oropharyngeal mucosa impedes perfusion. In a recent study, our group showed that pharyngeal mucosal perfusion is progressively reduced in the posterior pharynx when mucosal pressure is increased from 34 to 80 cmh 2 O [16]. Although mucosal pressures with the LMA are generally lower than 34 cmh 2 O, they can exceed this value in some locations at higher cuff volumes [7, 17, 18]. The higher incidence of dysphagia at high cuff volumes may be related to mucosal ischaemia or trauma to pharyngeal muscles through stretching. A limitation of our study was that cuff volumes were unknown during emergence. Although initial cuff volumes were known, nitrous oxide diffuses rapidly into the cuff and increases cuff pressure and volume during surgery [19]. However, the impact of nitrous oxide diffusion would have been similar between groups since the duration of anaesthesia was similar. It is possible that the study outcome might have been different if the cuff volumes had been similar during anaesthesia and then adjusted to high and low volume for emergence, but such a pattern of adjustment would not mimic common clinical practice. Similarly, we chose different initial cuff volumes rather than selecting and maintaining different intracuff pressures because intracuff pressures are rarely measured and maintained in clinical practice (J.B., clinical observation). A further limitation of our study was that postoperative data were collected unblinded. This was caused by the availability of only one data collector who could not be blinded to both the emergence and the interview phases. However, the interviews were structured and the patients blinded to the volume of air in the cuff. The incidences of sore throat, dysphonia and dysphagia in the LMA-Low group were similar to those in a previous double-blind study by our group with a similar mean cuff volume [20]. We conclude that, in general, emergence characteristics not affected by initial cuff volume, but that pharyngolaryngeal morbidity is more likely at high cuff volumes. Acknowledgments We wish to thank J. Hussain, L. Martin, M. Scully, F. Merritt, S. Hall, J. Sartain, P. McMahon, P. Talbutt, G. Clarke, S. Donald, J. Archdeacon and the operating theatre nursing staff at Cairns Base Hospital for their assistance. References 1 Brain AIJ, Denman WT, Goudsouzian NG. LMA Instruction Manual. San Diego, CA: Gensia Inc., Devitt JH, Wenstone R, Noel AG, O'Donnell RRT. The laryngeal mask airway and positive-pressure ventilation. Anesthesiology 1994; 80: 550±5. 3 Wakeling HG, Butler PJ, Baxter PJC. The laryngeal mask airway: a comparison between two insertion techniques. Anesthesia and Analgesia 1997; 85: 687±90. 4 Gataure PS, Latto IP, Rust S. Complications associated with removal of the laryngeal mask airway: a comparison 342 Q 2000 Blackwell Science Ltd

6 J. Brimacombe et al. Emergence with the laryngeal mask airway of removal in deeply anaesthetised versus awake patients. Canadian Journal of Anaesthesia 1995; 42: 1113±16. 5 Nandwani N, Fair eld MC, Krarup K, Thompson J. The effect of laryngeal mask airway insertion on the position of the internal jugular vein. Anaesthesia 1997; 52: 77±83. 6 Keller C, Puehringer F, Brimacombe J. The in uence of cuff volume on oropharyngeal leak pressure and breoptic position with the laryngeal mask airway. British Journal of Anaesthesia 1998; 81: 186±7. 7 Brimacombe J, Keller C. Laryngeal mask airway size selection in males and female: ease of insertion, oropharyngeal leak pressure, pharyngeal mucosal pressures and anatomical position. British Journal of Anaesthesia 1999; 82: 703±7. 8 Burgard G, Mollhoff T, Prien T. The effect of laryngeal mask cuff pressure on postoperative sore throat incidence. Journal of Clinical Anesthesia 1996; 8: 198± Rieger A, Brunne B, Striebel HW. Intracuff pressures do not predict laryngopharyngeal discomfort after use of the laryngeal mask airway. Anesthesiology 1997; 87: 63±7. 10 Asai T, Howell TK, Koga K, Morris S. Appropriate size and in ation of the laryngeal mask airway. British Journal of Anaesthesia 1998; 80: 470±4. 11 Brimacombe J, Berry A. Translucent vinyl tubing ± an alternative bite guard for the LMA. Anaesthesia and Intensive Care 1993; 21: 893±4. 12 Brimacombe J, Berry A, Fletcher D. A training program for laryngeal mask airway removal in the PACU. Journal of Post Anaesthesia Nursing 1993; 8: 236±7. 13 Poh J, Brimacombe J. A comparison of the T-piece, Venturi T-piece and T-bag for emergence with the laryngeal mask. Anaesthesia and Intensive Care 1998; 26: 526±8. 14 Nunez J, Hughes J, Wareham K, Asai T. Timing of removal of the laryngeal mask airway. Anaesthesia 1998; 53: 126± Brimacombe J, Keller C. The laryngeal mask airway in fresh cadavers versus paralysed anaesthetised patients: ease of insertion, airway sealing pressure, intracuff pressures and anatomic position. European Journal of Anaesthesiology 1999; 16: 699± Brimacombe J, Keller C, Puehringer F. Pharyngeal mucosal pressure and perfusion. A beroptic evaluation of the posterior pharynx in anesthetized adult patients with a modi ed cuffed oropharyngeal airway. Anesthesiology 1999; 91: 1661±5. 17 Keller C, Brimacombe J. Pharyngeal mucosal pressures, airway sealing pressures and beroptic position with the intubating versus the standard laryngeal mask airway. Anesthesiology 1999; 90: 1001±6. 18 Brimacombe J, Keller C. A comparison of pharyngeal mucosal pressure and airway sealing pressure with the laryngeal mask airway in anesthetized adult patients. Anesthesia and Analgesia 1998; 87: 1379± Lumb AB, Wrigley MW. The effect of nitrous oxide on laryngeal mask cuff pressure. In vitro and in vivo studies. Anaesthesia 1992; 47: 320±3. 20 Brimacombe JR, Brimacombe JC, Berry A, et al. A comparison of the laryngeal mask airway and cuffed oropharyngeal airway in adult patients. Anesthesia and Analgesia 1998; 87: 147±52. Q 2000 Blackwell Science Ltd 343

International Journal of Health Sciences and Research ISSN:

International Journal of Health Sciences and Research www.ijhsr.org ISSN: 2249-9571 Original Research Article Evaluation of Postoperative Sore Throat and Hoarseness of Voice with Three Variants of Laryngeal