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

Effect of superior laryngeal nerve block in alleviating sore throat after application of i-gel supraglottic airway: a randomized controlled trial

BACKGROUND

Postoperative sore throat (POST) is a common complaint after supraglottic airway device (SAD) application. Internal branch of the superior laryngeal nerve (iSLN) block has the potential to alleviate POST. The aim of this trial was to explore the effect of iSLN block in alleviating sore throat, as well as to identify the potential risk factors for POST after SAD insertion.

METHODS

One hundred thirty-four patients scheduled for elective gynecological surgery were randomized to either group T: tetracaine syrup (1%) for local lubrication on i-gel supraglottic device (n = 67) or group B: i-gel insertion with water based lubricant on it and followed by bilateral iSLN block (ropivacaine, 0.375%, 2 ml for each side) (n = 67). Under ultrasound guidance, iSLN was exposed below thyrohyoid membrane. The primary outcome was the intensity of sore throat at 6 h after surgery. In addition, POST score at 0.5 h and 24 h, the severity of postoperative swallowing discomfort, acoustic analysis and complications were measured.

RESULTS

Compared with tetracaine syrup for local lubrication, iSLN block resulted in a reduced intensity of POST at 0.5 h (P = 0.044, OR = 1.99, 95%CI 1.02 to 3.88) and 6 h (P < 0.001, OR = 5.07, 95%CI 2.53 to 10.14) after surgery, as well as less severity of swallowing discomfort (P < 0.001, OR = 2.21, 95%CI 1.63 to 2.99) and cough (P = 0.039, OR = 1.97, 95%CI 1.04 to 3.73). The patients after iSLN block presented lower jitter and shimmer value in acoustic analysis at 6 h after surgery (P < 0.001).

CONCLUSIONS

iSLN block was effective in alleviating POST, improving voice function, as well as reducing postoperative swallowing discomfort and coughing.

TRIAL REGISTRATION

Chinese Clinical Trial Registry (ChiCTR2000037974) on 8th Sept 2020.

The Comparison Between Inhalation and Total Intravenous Anesthesia Effect on Voice With Supraglottic Airway Devices for Short-term Anesthesia

OBJECTIVE

Supraglottic airway devices (SADs) are a good alternative to endotracheal intubation (ETI) in short-term anesthesia applications since they have advantages including easy application, lower cost, enabling spontaneous ventilation. Total intravenous anesthesia (TIVA) and desflurane anesthesia allowing rapid recovery are anesthesia methods to be selected. Inhalation anesthesia by desflurane may cause adverse effects on airway mucosa and vocal cord functions. The aim of the present study was to compare the effect of the chosen anesthesia method on voice in gynecological patients who underwent short-term anesthesia with SADs.

MATERIAL AND METHOD

Seventy four patients whom short-term surgical procedure was planned in the Gynecology and Obstetrics Clinic were randomized into two groups for desflurane anesthesia (group D) and TIVA (group T). Voice recording was performed through larynx examination before anesthesia. Perioperative hemodynamic parameters, airway complications and postoperative airway complications were recorded. Laryngeal examination and voice recording were performed for the second time after 24 hours following the anesthesia procedure. Acoustic voice analysis of the patients was evaluated through the Praat program. The conditions including sore throat, dysphagia, and hoarseness were investigated after the anesthesia. Acoustic and aerodynamic properties of the voice, airway complications and pharyngolaryngeal complaints related to the use of SADs were compared in the patients.

RESULT

There was not any significant difference between the groups for demographic data. The SADs type and size have similar characteristics. No significant difference was detected between Group T and Group D for anesthesia duration (P = 0.964). Both anesthesia methods cause similar effects on pharyngolaryngeal functions and voice. No significant difference was found between Group T and Group D in parameters other than the shimmer value of acoustic analysis. A statistically significant increase was observed in the Shimmer variable of group D (P < 0.05). When group T and group D were compared, there was not any significant difference in terms of airway complications, sore throat, dysphagia, and hoarseness.

CONCLUSION

The TIVA and desflurane anesthesia presented similar clinical effects on voice and pharyngolaryngeal morbidity in the short-term gynecological operations through SADs. The increased shimmer value of acoustic voice analysis in Group D suggests that desflurane anesthesia may cause clinically insignificant deterioration on the voice. Further comprehensive studies are needed in order to demonstrate the effect of anesthetic agents on larynx functions in patients whom SADs is used.

Internal branch of superior laryngeal nerve block by dexamethasone alleviates sore throat after thyroidectomy: a randomized controlled trial

PURPOSE

Postoperative sore throat (POST) is a common complaint following thyroidectomy. Dexamethasone was reported to alleviate POST when administered via different routes. This study aimed to compare the effects of local spray and perineural injection surrounding the internal branch of superior laryngeal nerve (iSLN) in preventing POST and alleviating postoperative impaired voice function.

METHODS

A randomized, double-blinded, controlled trial was performed to test the efficacy of the iSLN block in inhibiting of POST. A total of 161 patients who underwent elective thyroidectomy were randomly allocated to two groups. Group Spray: 4 mg dexamethasone was sprayed on to the vocal cord; Group iSLN: bilateral perineural injection with 4 mg dexamethasone around the iSLN. The incidence and severity of POST, swallowing pain, and its side effects were evaluated. Postoperative acoustic analysis, including jitter and shimmer, was also performed.

RESULTS

Group iSLN exhibited a significantly less incidence and intensity of POST at 6 h and 24 h (P < 0.001). The patients experienced less swallowing pain at 6 h (P < 0.001) after the surgery, compared with Group Spray. When compared with Group Spray, Group iSLN improved postoperative voice function, which was characterized by lower jitter and lower shimmer value at 6 h and 24 h (P < 0.001) after the surgery. The severity of postoperative cough is higher in Group Spray (P < 0.001).

CONCLUSIONS

Among patients undergoing elective thyroidectomy, those who received perineural injection surrounding iSLN with dexamethasone had improved voice function and presented with more excellence in the inhibition of POST and cough, in comparison with the local spray.

REGISTER INFORMATION

This trial was registered in the Chinese Clinical Trial Registry on 4th Jan, 2021 (ChiCTR2100042145). The trial is registered at http://www.chictr.org.cn/showproj.aspx?proj=120142 .

The Effect of Different Types of Laryngeal Mask Airways on Sound Quality: A Prospective Randomized Study

Background

Although the deterioration in sound quality is not as much as endotracheal intubation, it can also be seen after the use of laryngeal mask airway (LMA). The aim of this study is to investigate the effects of different LMA types on voice performance.

Methods

This study included 88 patients aged 18-80 years, whose surgical procedure was not planned to take longer than 120 minutes. In the acoustic voice analysis, F0, jitter%, and shimmer% were examined. In addition, the Voice Handicap Index (VHI)-30 questionnaire has completed an evaluation of voice quality. The patients were randomly divided into two groups (I-gel LMA [n=44]; Classic LMA [n=44]) according to the closed envelope method.

Results

A total of 88 patients were included in the study. Demographic data of the patients were statistically similar between the groups (p > 0.05). The changes in the preoperative and postoperative F0, jitter, and VHI-30 values in the I-gel group were statistically significant (p: 0.002, p: 0.001, p < 0.001). Shimmer values were not significantly different (p: 0.762). In the classical LMA group, preoperative and postoperative F0, jitter, shimmer, and VHI-30 values were statistically significantly different (p: 0.001, p: 0.012, p: 0.036, p < 0.001).

Conclusion

I-gel LMA and classic LMA negatively affect voice performance in the preoperative and postoperative periods. This situation was also observed in the VHI-30 index test. However, when this situation was evaluated in terms of shimmer analysis, the decrease in voice quality in the early postoperative period was more limited in the I-gel group.

Comparison of laryngeal morbidities with modified reinforced silicone tube intubation guided over a bougie vs. a guidewire: novel assessment with voice analysis

Semi-rigid flexible introducer-guided tracheal intubation is associated with pharyngolaryngeal morbidities. We compared the practice of railroading a newly described modified reinforced silicone tracheal tube with a built-in guide channel in its wall over a non-kinking guidewire with railroading the same tube over a disposable bougie, with respect to pharyngolaryngeal morbidities. One hundred and twenty-four ASA 1 and 2 adults were randomly assigned to undergo bougie-guided (n = 62) or wire-guided (n = 62) intubation under general anaesthesia. All patients were assessed for postoperative pharyngolaryngeal complaints. In addition, voice parameters (fundamental frequency, shimmer, jitter and harmonic noise ratio) with vowels 'a' and 'i' were analysed pre-operatively and 24 h postoperatively. The success of first-attempt intubation and the associated haemodynamic response were also recorded. A higher incidence of pharyngolaryngeal complaints was seen in the bougie group, 48.3%, 95%CI (35.9-60.9%) when compared with wire-guided group 28.3%, 95%CI (18.0-40.6%), p = 0.01. Postoperatively, all the voice parameters were significantly more affected when compared with their pre-operative value in the bougie-guided group (p < 0.05) but not in the wire-guided group. The success of first-attempt intubation was similar in both groups. Wire-guided orotracheal intubation was associated with a lower incidence of pharyngolaryngeal complaints and effect on voice when compared with bougie-guided intubation.