Supraglottic Airway Devices and Effect on Voice—Comparison of LMA Proseal and i-gel: Double-Blind Randomized Clinical Trial *Shriram Vaidya, *Pankaj Kundra, †Surianarayanan Gopalakrishnan, †Pradiptakumar Parida, *Kotteeswaran Yuvaraj, and ‡Manju Mohan P., *yPondicherry and z Kerala, India Summary: Objectives. Laryngeal mask airway (LMA) is an important alternative to endotracheal intubation for all professional voice users undergoing surgery. However, dysphonia is a known complication of LMA Proseal (PLMA) use. The i-gel airway (IGA) provides adequate airway seal without the need for an inflatable cuff. Hence, it helps to minimize the risk of tissue compression. This study compares effect of PLMA and IGA on voice at 24th hour after anesthesia. Design. This is a double-blind randomized clinical trial. Methods. Ninety anesthesiologists class 1 adults scheduled for surgeries lasting up to 60–120 minutes were included in the study. Participants were randomly allocated to group PLMA (n ¼ 43) and group IGA (n ¼ 43). Cuff pressure was monitored and maintained at just seal pressure in group PLMA. Voice was evaluated using perceptive and acoustic analysis (jitter, shimmer, and harmonics-to-noise ratio [HNR]) preoperatively and at 24th hour after anesthesia. Voice of patients with pharyngolaryngeal complaints was categorized into rough, breathy, asthenic, strain, or normal pattern. Results. Acoustic parameters jitter, shimmer, and HNR deteriorated significantly in both group PLMA and IGA albeit the change being comparable. Incidence of pharyngolaryngeal complaints was similar in both the groups. A total of 10% patients in group PLMA and 12.5% in group IGA developed breathy voice significant deterioration in all acoustic variables at 24th postoperative hour, but differences were not significant between group PLMA and group IGA. Conclusions. PLMA and IGA both produce comparable and significant deterioration in acoustic variables at 24th hour after short duration general anesthesia. Key Words: Dysphonia–Hoarseness of voice–Laryngeal masks–Postoperative complications–Acoustics. INTRODUCTION Supraglottic airway devices (SADs) are extensively used to manage airway in current anesthesia practice. Endotracheal intubation is known to produce more postoperative pharyngolaryngeal morbidity including change in voice compared to laryngeal mask.1–3 Hence, laryngeal mask airway (LMA) is proposed as an important alternative to endotracheal intubation for professional voice users undergoing surgery.2,4 However, dysphonia is a known complication of LMA use.5 There is an increasing tendency among anesthesiologists (ASAs) to prefer second generation SADs6 such as LMA Proseal (PLMA) over first generation SADs represented by LMA Classic, as the former provide superior airway sealing pressures and allow insertion of drain tube to vent the stomach.7 A newer SAD i-gel airway (IGA) provides adequate airway seal without the need for an inflatable cuff. Hence, it helps to minimize the risk of tissue compression8 with resultant reduction in incidence of postoperative pharyngolaryngeal morbidity.9 However, to date, no randomized clinical trial has been conducted with the aim of comparing second generation

Accepted for publication June 15, 2015. From the *Department of Anaesthesiology & Critical Care, Jawaharlal Institute of Postgraduate Medical Education and Research, Pondicherry, India; yDepartment of Otorhinolaryngology, Jawaharlal Institute of Postgraduate Medical Education and Research, Pondicherry, India; and the ySree Chitra Tirunal Institute for Medical Sciences & Technology, Trivandrum, Kerala, India. Address correspondence and reprint requests to Pankaj Kundra, Department of Anaesthesiology & Critical Care, Jawaharlal Institute of Postgraduate Medical Education and Research, Pondicherry 605006, India. E-mail: [email protected] Journal of Voice, Vol. -, No. -, pp. 1-7 0892-1997/$36.00 Ó 2015 The Voice Foundation http://dx.doi.org/10.1016/j.jvoice.2015.06.006

SADs PLMA and IGA with inflatable and noninflatable cuffs, respectively, in terms of their effect on pharyngolaryngeal morbidity in the postoperative period. This study was designed with the aim to compare the effect of PLMA and IGA on voice. MATERIALS AND METHODS This study was conducted between March 2011 and July 2012, after obtaining approval from Institute Ethics Committee (Human Studies) at Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry (Ref: SEC/ 2011/1/1) and is registered with Australian New Zealand Clinical Trials Registry. Ninety American Society of Anesthesiologists class 1 adults scheduled for elective surgeries, with expected duration up to 120 minutes, were included in the study after obtaining written informed consent (Table 1). Patients with expected difficult airway, head and neck surgery, abdominal surgery, thoracotomy, risk of aspiration, or preexisting lung disease were excluded. Voice of participants was evaluated 24 hours before surgery by acoustic analysis and perceptively by an experienced speech pathologist by assessing the voice for presence of roughness, breathiness, asthenia, or strain.10 All the patients were also subjected to videostrobolaryngoscopy for the video documentation of laryngeal anatomy along with its mechanical function. Patients who had preexisting abnormality on perceptive analysis and videostrobolaryngoscopy were excluded from the study. The voice samples for acoustic analysis11 were obtained under guidance of a speech pathologist through a microphone placed 15 cm away from patient’s left angle of mouth at 45 angle. Sound card used for recording voice samples was compatible with

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TABLE 1. Type of Surgeries Type of Surgeries Mesh repair Mastectomy Fibroadenoma excision SSG left leg raw area Stump revision post right leg amputation Orchidectomy SSG left hand Melanoma excision foot

n ¼ 80 37 14 22 1 1 2 1 2

Windows Operating System, and had 16-bit resolution and 44.1kHz sampling frequency. Recordings were obtained in noiseisolated room with ambient noise intensity less than 50 dB. Sustained phonation by patient of vowels /a/, /i/, and /u/ at a comfortable pitch and loudness resulted in recordings of 3-second samples of oscillographically steady portion of each vowel (excluding the onset and offset). Oscillographic steadiness of the sample was decided on the basis of the presence or absence of unvoiced segments and voice breaks. Trials were repeated till acceptable samples were generated. Voice samples were saved in wave format on the hard disc of laptop Compaq Presario CQ62 (Palo Alto, CA). The phonetic analysis was performed using software Praat12 (Paul Boersma and David Weenink; Phonetic Sciences University of Amsterdam, Spuistraat, Amsterdam, The Netherlands). Acoustic variables jitter, shimmer, and harmonics-to-noise ratio (HNR) for each recorded vowel were evaluated as indicators of voice perturbations.13 Average jitter, shimmer, and HNR of three vowels were calculated. After complete evaluation of voice, patients were randomized into group PLMA (n ¼ 43) and group IGA (n ¼ 43) for airway management with PLMA and IGA, respectively. On the day of surgery, patients recruited for the study were premedicated with oral diazepam 10 mg, metoclopramide 10 mg, and famotidine 20 mg, 90 minutes before surgery. Baseline and continuous recording of ECG, hemodynamic parameters (heart rate and noninvasive blood pressure), and hemoglobin saturation was performed using a multiparameter monitor. Anesthesia was induced with sleep dose of thiopentone following administration of 2 mcg/kg of fentanyl. Neuromuscular blockade was established with atracurium 0.5 mg/kg, and anesthesia was maintained with 1 MAC of isoflurane and 66% nitrous oxide in 33% oxygen using anesthetic agent and gas monitoring. Appropriate sizing of PLMA and IGA was based on body weight as recommended by the manufacturer. Insertions of SADs were performed after 3 minutes of neuromuscular blockade by digital method by anesthetists who had performed more than 100 insertions of both the devices. Neuromuscular blockade was maintained with 0.15 mg/kg boluses of atracurium. Uniformity in lubrication and method of insertion of SAD was ensured by following the instructions in manufacturer’s manual. Patients requiring more than one attempt were excluded from the study. Proper positioning of the device was confirmed by square-wave capnogram, normal thoracoabdominal movements, and lack of audible leak. Cuff pressure of

PLMA was reduced to the minimum required to maintain ‘‘just seal’’14 using a syringe. Gastric tube was inserted to avoid any possible increase in intra-abdominal pressure. Postoperative pain relief was provided with multimodal analgesic technique comprising of peripheral nerve blocks whenever possible, intravenous paracetamol 1 g intravenously every 6 hours, and ketorolac 30 mg intramuscular on demand or when VAS was more than 5. No narcotic analgesics were used as they would interfere with voice analysis. Patient’s lungs were ventilated with 8 mL/kg of tidal volume at 12 breaths/min through anesthesia ventilator. Fresh gas flow of 6 L/min was used through circle system and then reduced to 1 L/min after 20 min. Heat and moisture exchanging (HME) filter (Intersurgical Ltd; Crane House, Molly Millars Lane Wokingham, Berkshire, United Kingdom) was always used in the expiratory limb. Cuff pressure was monitored using a handheld airway pressure manometer (pressure easy cuff pressure monitor; Portex, Germany) and never allowed to cross the recommended maximum of 60 cm H2O. The SAD was removed with the cuff fully deflated in case of PLMA once the subject was awake and able to open mouth on command. The need for pharyngeal suctioning and blood streaking of SAD were noted. Participants were questioned directly15 by the otorhinolaryngologist blinded to the study groups regarding presence or absence of laryngopharyngeal complaints16 at 24th hour after anesthesia. Acoustic analysis and videostrobolaryngoscopy were repeated at 24th postoperative hour. The voice of patients with pharyngolaryngeal complaints was further analyzed under the guidance of a speech pathologist and categorized into rough, breathy, asthenic, strained, and normal pattern.10 Statistical analysis Postpriori power analysis with change in HNR from preoperative value (group PLMA 0.71 ± 0.59, group IGA 1.08 ± 0.61) as primary parameter with alpha error of 0.05 resulted in power of 89.3% for a sample size of 40 in each group. HNR was considered as primary parameter for acoustic analysis and power analysis as it represents both frequency and amplitude perturbation in the voice17 as compared to jitter and shimmer which represent either frequency or amplitude perturbation, respectively. Demographic data were analyzed by chi-square test and Fisher exact test. Phonetic parameters—jitter, shimmer, and HNR—were analyzed using paired and unpaired t tests. SPSS Version 16 (SPSS Inc, Chicago, IL) was used to carry out all the statistical analysis. RESULTS Out of 90 patients enrolled for the study, four were found to have abnormal voice on preoperative perceptive analysis and hence were excluded from the study. Eighty-six patients were randomized into two groups—group PLMA (n ¼ 43) and group IGA (n ¼ 43). One patient in each group was excluded as more than one attempt was made to insert SAD. One patient from PLMA and two from IGA group were excluded as the duration of surgery exceeded 120 minutes, and one patient had to be excluded as he was lost to follow-up and discharged within 24 hours (Figure 1).

Shriram Vaidya, et al

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LMA Proseal and i-gel: Effect on Voice

Enrollment Assessed for eligibility (n=90)

Excluded (n= 4) Not meeting inclusion criteria (n=0) Declined to participate (n=0) Other reasons (n=4)

Randomized (n=86)

Allocation Allocated to intervention Group PLMA (n=43) Received allocated intervention (n=40) Did not receive allocated intervention (more than 1 attempt/Surgery>120 min) (n=3)

Allocated to intervention Group IGA (n=43) Received allocated intervention (n=41) Did not receive allocated intervention (more than 1 attempt/ Surgery>120 min) (n=2)

Follow-Up Lost to follow-up (n=0)

Lost to follow-up (early discharge) (n=1)

Discontinued intervention (n=0)

Discontinued intervention (n=0)

Analysis Analyzed (n=40)

Analyzed (n=40)

Excluded from analysis (n=0)

Excluded from analysis (n=0)

FIGURE 1. Flowchart of patients during study and analysis. The physical, demographic characteristics, duration of surgery, and preoperative phonetic parameters were comparable in both the groups (Table 2). Postoperative acoustic analysis of voice demonstrated deterioration in jitter, shimmer, and HNR when compared to preoperative values in both the groups. Jitter increased by 30.3 ± 44% and

45.54 ± 34% from the baseline in group PLMA and IGA, respectively, P < 0.002. Similarly, shimmer also increased significantly in both the groups (group PLMA 31.35 ± 41.6%; group IGA 25.16 ± 18.2%), P < 0.000. Significant decrease in HNR was observed in group IGA (8.58 ± 11.9%, P value < 0.000) but not in group PLMA when compared to the baseline value (Figure 2).

TABLE 2. Physical Characteristics and Preoperative Acoustic Variables Patient Characteristics Physical characteristics Age (y) Weight (kg) Duration of surgery (min) Sex (male: female) Preoperative acoustic variables Jitter (%) Shimmer (%) HNR (dB) Notes: Data expressed as mean ± standard deviation. Notes: P value < 0.05 is significant.

Group PLMA (n ¼ 40)

Group IGA (n ¼ 40)

P Value

36.8 ± 13.6 55.5 ± 9.8 86.8 ± 23.3 16:24

38.8 ± 12.8 56.4 ± 9.2 84.5 ± 19.4 19:21

0.51 0.67 0.62 0.65

0.524 ± 0.62 5.392 ± 4.57 12.013 ± 3.38

0.365 ± 0.20 4.505 ± 2.09 12.53 ± 2.46

0.126 0.269 0.331

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FIGURE 2. Preoperative versus postoperative percentage change in acoustic variables. *Indicates P value < 0.002. **Indicates P value < 0.001. S.D., standard deviation.

Postoperatively, laryngopharyngeal complaints were recorded in eight patients belonging to group PLMA and nine in group IGA. Acoustic analysis of voice did not show any significant difference in these 17 patients (Table 3). Mean jitter, shimmer, and HNR of the patients, who had laryngopharyngeal complaints (n ¼ 17), were similar to those without complaints (n ¼ 63; Table 4). Perceptive evaluation of voice in 17 patients with laryngopharyngeal complaints by a speech pathologist revealed nine patients with breathy voice, and these patients demonstrated significant deterioration in all three acoustic variables (Table 5). Patients with rough (n ¼ 4), normal (n ¼ 3), and asthenic voice (n ¼ 1) did not show any significant postoperative change in acoustic variables when compared to their baseline values. Mean postoperative percent deterioration in jitter and HNR of the patients who had breathy voice (n ¼ 9) was significantly more than the others who did not have breathy voice (n ¼ 71; Figure 3). Postoperative strobolaryngoscopy revealed mild to moderate asymmetry in extent of glottic wave excursion and vocal fold lateral displacement with unilateral drooping of arytenoid in one patient in PLMA and two in IGA group. In addition, one patient in PLMA group had mild incomplete glottic closure with posterior phonatory gap. However, repeat strobolaryngoscopy at 48 postoperative hours failed to notice any abnormality among these participants, reaffirming the transient nature of neuropraxia due to placement of SADs. Postoperative jitter, shimmer, and HNR between group PLMA and group IGA did not reveal a significant difference. None of the patients reported laryngopharyngeal complaints when enquired 48 hours after anesthesia.

DISCUSSION In our study, we have demonstrated that after elective surgeries of duration less than 120 minutes, both PLMA and IGA produce significant deterioration in acoustic variables at 24th hour.

However, both the devices produced similar change in acoustic variables (jitter, shimmer, and HNR). Endotracheal tube is known to produce more postoperative change in voice compared to laryngeal mask.1–3 IGA, a relatively new cuffless pharyngeal sealer, is claimed to produce lesser tissue compression compared to cuffed SADs, as it is designed to fit the perilaryngeal and hypopharyngeal structures anatomically without the use of an inflatable cuff.9 However, in our study, the incidence of laryngopharyngeal complaints was not different between PLMA and IGA (20% vs 22.5%, respectively). Laryngopharyngeal discomfort is a subjective perception that depends on the patient’s ability to report symptoms as well as interview method.15 The authors noticed that patients were unable to accurately categorize their complaints into dysphagia, dysphonia, or hoarseness. In addition, patients with vocal fold palsy after LMA use were found to complain of more than one symptom in previously published case reports.5 Hence, patients’ symptoms were broadly identified as laryngopharyngeal complaints rather than dysphonia, dysphagia, or hoarseness and then subjected to acoustic analysis to minimize the possibility of failing to identify any case of vocal fold palsy. A more objective tool like acoustic analysis can delineate the change in voice secondary to vocal fold dysfunction from other nonspecific complaints.

TABLE 3. Acoustic Variables of Patients With Laryngopharyngeal Complaints—Group PLMA Versus Group IGA Patient Characteristics

Group PLMA (n ¼ 8)

Group IGA (n ¼ 9)

P Value

Jitter (%) Shimmer (%) HNR (in dB)

0.876 ± 0.45 9.097 ± 2.63 8.647 ± 2.98

0.762 ± 0.56 6.853 ± 3.10 10.28 ± 3.06

0.654 0.132 0.282

Notes: Data expressed as mean ± standard deviation. Notes: P value < 0.05 is significant.

Shriram Vaidya, et al

TABLE 4. Comparison of Acoustic Variables of Patients With and Without Laryngopharyngeal Complaints Percentage Postoperative Change in Acoustic Variables Patient With Complaints No Complaints Characteristics (n ¼ 17) (n ¼ 63) P Value Jitter Shimmer HNR

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LMA Proseal and i-gel: Effect on Voice

53.92 ± 57.9 37.73 ± 32.54 8.68 ± 23.4

33.67 ± 32.6 25.69 ± 31.7 5.47 ± 18.3

0.066 0.171 0.548

Notes: Data expressed as mean ± standard deviation. Notes: P value < 0.05 is significant.

Phonetic analysis of voice Increase in jitter and shimmer represents increase in cycle-tocycle microperturbations in frequency and amplitude of voice indicating impaired vocal fold function. Decrease in HNR is suggestive of increase in fraction of noise in voice. These changes are consistent with the acoustic changes in vocal fold palsy.13 Apart from neuropraxia, postoperative change in voice after use of SADs depends on various other factors comprising of high intracuff pressures,18 drying of the airway,19 and difficulty in patient cooperation during tests due to significant postoperative pain and central causes. Cuff pressure of PLMA was maintained at ‘‘just seal’’ pressure. We did not encounter any excessive secretion or pooling of oropharynx which would theoretically breach the ‘‘just seal’’ pressure and result in airway soiling and postoperative laryngopharyngeal complaints.20 HME filters were used to

prevent drying of vocal folds. PLMA cuff was deflated before removal to prevent injury to cricoarytenoid joint.5 Postoperative analgesia was ensured with local anesthetic blocks that were continued in the postoperative period and by timely administration of Non Steroidal Anti Inflammatory Drugs and opioids. To ensure complete patient cooperation and exclude influence of central causes, voice was assessed 24 hours after surgery. Recurrent laryngeal neuropraxia can produce breathy voice and deterioration in jitter, shimmer, and HNR because of incomplete approximation of vocal folds during phonation. Despite significant deterioration in phonetic variables with both PLMA and IGA suggesting neuropraxia, the clinically discernible breathy voice was identified by the speech pathologist in only 9 of 80 patients studied. Significant increase in HNR in voice of patients with breathy voice (n ¼ 9) as compared to those without breathy voice (n ¼ 71) (Figure 3) is consistent with clinically manifest neuropraxia.

Perceptive analysis of voice Perceptive analysis of voice by the speech pathologist in the postoperative period differentiated patients with breathy voice suggestive of impaired closure of glottis (n ¼ 9) from others with rough, asthenic, and normal voice (total n ¼ 8). Incidence of breathy voice was found to be similar between group PLMA and IGA (10% and 12.5%, respectively) indicating the similar propensity of both the SADs to cause vocal fold dysfunction secondary to neuropraxia despite ruling out incorrect placement, incorrect size and maintaining ‘‘just seal’’ pressures with PLMA. The risk of neuropraxia still remains as the recurrent laryngeal nerve is extremely vulnerable to compression by

TABLE 5. Changes in Acoustic Variables and Clinical Categorization of Voice Quality in 17 Patients With Postoperative Laryngopharyngeal Complaints Patient Characteristics Breathy voice (n ¼ 9) Jitter (%) Shimmer (%) HNR (dB) Rough voice (n ¼ 4) Jitter (%) Shimmer (%) HNR (dB) Normal voice (n ¼ 3) Jitter (%) Shimmer (%) HNR (dB) Asthenic voice (n ¼ 1) Jitter (%) Shimmer (%) HNR (dB)

Preoperative

Postoperative

Percent Change

P Value

0.523 ± 0.30 4.922 ± 1.95 10.832 ± 3.43

0.946 ± 0.57 6.983 ± 1.82 8.045 ± 1.91

83.338 ± 52.98 43.94 ± 29.11 23.01 ± 14.62

0.006* 0.001* 0.016*

0.573 ± 0.34 5.824 ± 2.35 9.396 ± 3.46

0.849 ± 0.51 7.559 ± 3.79 9.327 ± 3.56

45.873 ± 36.13 25.546 ± 14.78 0.902 ± 15.19

0.110 0.130 0.935

0.533 ± 0.41 8.095 ± 3.70 12.262 ± 3.59

0.443 ± 0.12 9.330 ± 4.08 12.960 ± 2.54

5.436 ± 43.67 16.082 ± 14.56 8.902 ± 25.2

0.651 0.295 0.688

1.032 10.790 9.649

0.643 13.385 13.262

37.75 24.05 36.41

0.152 0.128 0.232

Notes: Data expressed as mean ± standard deviation. Notes: *P value < 0.05 is significant.

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Journal of Voice, Vol. -, No. -, 2015

trials evaluate the effect on acoustic changes in voice after prolonged anesthesia. Acknowledgments Authors would like to thank and acknowledge the Department of Speech Pathology, JIPMER for their valuable advice. There are no conflicts of interests and funding to disclose. REFERENCES

FIGURE 3. Percentage change in acoustic variables—Patients with breathy voice (n ¼ 9) versus patients without breathy voice (n ¼ 71). Breathy (n ¼ 9). Others (n ¼ 71). *Indicates P value < 0.05. Ratio of harmonic and noise components in a voice spectrum. HNR, harmonics-to-noise ratio; S.D., standard deviation.

the tip of SADs as it crosses the lower border of the inferior constrictor of pharynx.21 The scarcity of reports describing nerve injury after use of IGA could be due to the recent introduction of the device compared to PLMA. In a few reports of lingual and inferior alveolar nerve injury produced by IGA, the heavy and bulky design of the device is postulated as the cause.22,23 Insertion-related pharyngolaryngeal complications can also occur with IGA because of the inherent semi-rigid nature of the device. Absence of cuff makes it impossible to achieve ‘‘just seal’’ pressure with IGA, which is achievable with PLMA as it provides for cuff pressure titration. Recent studies have demonstrated reduced pharyngolaryngeal morbidity if the cuff pressure is maintained at < 44 cm H2O.18 It could be understood that PLMA provides a safe air cushion around the surrounding structures in the laryngopharynx if ‘‘just seal’’20 pressures are used. CONCLUSIONS PLMA and IGA produce significant deterioration in acoustic variables at 24th hour after elective surgeries of duration less than 120 minutes. However, both the devices produced similar changes in acoustic variables (jitter, shimmer, and HNR). These changes are consistent with the acoustic changes in vocal fold palsy. PLMA and IGA produce significant change in voice at 24 hours after surgeries lasting between 60 and 120 minutes as suggested by the acoustic analysis of voice. However, there is no significant difference between PLMA and IGA with respect to effect on voice in postoperative period. Authors suggest caution for usage of these second generation SADs during surgeries lasting more than 120 minutes till further controlled

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Supraglottic Airway Devices and Effect on Voice-Comparison of LMA Proseal and i-gel: Double-Blind Randomized Clinical Trial.

Laryngeal mask airway (LMA) is an important alternative to endotracheal intubation for all professional voice users undergoing surgery. However, dysph...
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