Use of the laryngeal mask airway in oral and maxillofacial surgery

Laryngeal Mask Airway as an Appropriate Option in Pediatric Laparoscopic Inguinal Hernia Repair: A Systematic Review and Meta-Analysis

OBJECTIVE

To elucidate the safety and effectiveness of laryngeal mask airway (LMA) use in pediatric patients undergoing laparoscopic inguinal hernia repair.

METHODS

Studies were searched on the PubMed, EMBASE, and Cochrane Library databases. Only randomized controlled trials (RCTs) were included. Primary outcomes were major perioperative respiratory adverse events (PRAEs), namely laryngospasm, bronchospasm, desaturation, and aspiration. Secondary outcomes were minor PRAEs, anesthesia time, and recovery time. A meta-analysis was performed to calculate risk ratios (RR), weighted mean difference (WMD), and 95 % confidence intervals (CI) by using random effects models.

RESULTS

In total, 5 RCTs comprising 402 patients were included. Regarding major PRAEs, laryngospasm (RR: 0.43, 95 % CI: 0.12 to 1.47; p = 0.18), bronchospasm, and aspiration all demonstrated no difference between the laryngeal and endotracheal groups. Desaturation exhibited a trend, but this trend was not sufficiently supported with statistical evidence (p = 0.09). For minor PRAEs, fewer patients experienced incidence of cough after laryngeal mask use (RR: 0.27, 95 % CI: 0.11 to 0.67; p = 0.005). Other PRAE, namely hoarseness (p = 0.06), sore throat (RR: 1.88, 95 % CI: 0.76 to 4.66; p = 0.18), and stridor, did not differ between the 2 groups. Additionally, both anesthesia time (WMD: -6.88 min, 95 % CI: -11.88 to -1.89; p < 0.00001) and recovery time (WMD: -4.85 min, 95 % CI: -6.51 to -3.19; p < 0.00001) were shortened in the LMA group.

CONCLUSION

LMA used in pediatric laparoscopic inguinal hernia repair demonstrated no greater safety risks than endotracheal tube intubation did. Thus, anesthesiologists may shift from conventional endotracheal tube use to LMA use. Moreover, anesthesia and recovery times were shortened in the LMA group, which resulted in more efficient use of the operating room. Because of these benefits, LMA could be an appropriate option for pediatric patients undergoing laparoscopic inguinal hernia repair.

LEVEL OF EVIDENCE

Treatment Study, LEVEL III.

Efficacy of laryngeal mask airway against postoperative pharyngolaryngeal complications following thyroid surgery: a systematic review and meta-analysis of randomized controlled studies

This meta-analysis aimed at investigating the effectiveness of laryngeal mask airway (LMA) against postoperative pharyngolaryngeal complications after thyroidectomy. MEDLINE, Cochrane Library, google scholar, and EMBASE databases were searched from inception through February, 2021, for randomized controlled trials (RCTs) comparing the incidence of pharyngolaryngeal complications following the use of LMA or endotracheal tube (ETT). Pooled results from seven RCTs involving 600 patients showed an association of LMA with a reduced risk of postoperative sore throat (POST) at 24 h [risk ratio (RR) 0.75, p = 0.006, four trials], but not at 1 h and 48 h after thyroidectomy. POST severity and hoarseness risk were lower in the LMA group than the ETT group at 1 h, 24 h, and 48 h (all p < 0.05). Nevertheless, hoarseness severity was lower in the LMA group only at postsurgical 48 h [standardized mean difference = - 0.35, p = 0.008, three trials]. Moreover, the risk of emergence cough was lower in patients using LMA than those receiving ETT (RR = 0.14, p = 0.002, two trials). The two groups did not differ in the severity of dysphagia at postoperative 1 h, 24 h, and 48 h. This meta-analysis showed that LMA may be associated with fewer pharyngolaryngeal complications compared to ETT without airway impacts. The limited number of included studies warrants further research to support our findings.

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.

Advantages, Disadvantages, Indications, Contraindications and Surgical Technique of Laryngeal Airway Mask

The beauty of the laryngeal mask is that it forms an air tight seal enclosing the larynx rather than plugging the pharynx, and avoid airway obstruction in the oropharynx. The goal of its development was to create an intermediate form of airway management face mask and endotracheal tube. Indication for its use includes any procedure that would normally involve the use of a face mask. The laryngeal mask airway was designed as a new concept in airway management and has been gaining a firm position in anesthetic practice. Despite wide spread use the definitive role of the laryngeal mask airway is yet to be established. In some situations, such as after failed tracheal intubation or in oral surgery its use is controversial. There are several unresolved issues, for example the effect of the laryngeal mask on regurgitation and whether or not cricoids pressure prevents placement of mask. We review the techniques of insertion, details of misplacement, and complications associated with use of the laryngeal mask. We then attempt to clarify the role of laryngeal mask in air way management during anesthesia, discussing the advantages and disadvantages as well as indications and contraindications of its use in oral and maxillofacial surgery.

Flexible laryngeal mask airway management for dental treatment cases associated with difficult intubation

Nasotracheal intubation is generally a useful maxillofacial surgery that provides good surgical access for intraoral procedures. When nasotracheal intubation is difficult, laryngeal mask airway (LMA) insertion can be performed, and the flexible LMA™ (FLMA) is also useful for anesthetic management. However, the FLMA provides limited access to the mouth, which restricts the insertion of instrumentation and confines the surgical field available. Here, we present our experience using the FLMA airway management for dental treatment cases involving difficulty with intubation.

The use of laryngeal mask airway in dental treatment during sevoflurane deep sedation

Background

General anesthesia is frequently considered for pediatric patients, as they often find it difficult to cooperate and stay calm during administration of potentially painful treatments. Sedation can overcome these adversities; however, this is challenging while maintaining unobstructed airways.

Methods

The study involved 11 pediatric dental patients treated with LMA under deep sedation with sevoflurane, from 2011 through 2015. LMA size, sevoflurane concentration, and the vital signs of patients were assessed through a chart review.

Results

The age distribution of the patients ranged from 6 to 10 years old. A total of 3 patients underwent mesiodens extraction, while the remaining 8 underwent an surgically assisted orthodontic forced tooth eruption The average sedation period was approximately 45 minutes and the LMA size was 2½. The sevoflurane concentration was maintained at 2% on average, and overall, the measurements of vital signs were within the normal range; the patients had an average blood pressure of 98/49 mmHg, breathing rate of 26 times/min, pulse frequency of 95 times/min, SpO₂s level of 99 mmHg, and ETCO₂ level of 41.2 mmHg.

Conclusions

Deep sedation with sevoflurane coupled with LMA may be applied successfully in pediatric patients who undergo mesiodens extraction or a surgically assisted orthodontic forced tooth eruption.

Oropharyngeal oxygen and volatile anesthetic agent concentration during the use of laryngeal mask airway in children

BACKGROUND

The laryngeal mask airway is increasingly used as an airway adjunct during general anesthesia. Although placement is generally simpler than an endotracheal tube, complete sealing of the airway may not occur, resulting in contamination of the oropharynx with anesthetic gases. Oropharyngeal oxygen enrichment may be one of the contributing factors predisposing to an airway fire during adenotonsillectomy. The current study prospectively assesses the oropharyngeal oxygen and volatile anesthetic agent concentration during laryngeal mask airway use in infants and children.

METHODS

Following the induction of general anesthesia and placement of a laryngeal mask airway, the oropharyngeal gas sample was obtained by placing a 14-gauge catheter attached to the gas sampling tube into the oropharynx above the laryngeal mask airway. The oropharyngeal concentration of the oxygen and the anesthetic agent were recorded for five breaths during both spontaneous ventilation (SV) and positive pressure ventilation (PPV).

RESULTS

The study included 238 patients. The oropharyngeal concentration of sevoflurane was >50% of the inspired sevoflurane concentration during SV in 10 of 238 (4.2%) patients and during PPV in 135 of 238 (56.7%) patients. Similarly, during SV and PPV, the oropharyngeal oxygen concentration was >21% in 30 of 238 (12.6%) patients and in 188 of 238 (79%) patients, respectively. Significantly, we also noticed that the oropharyngeal oxygen concentration exceeded 50% in 5 of 238 (2.1%) patients during SV and in 139 of 238 patients (58.4%) patients during PPV.

CONCLUSIONS

With the use of a laryngeal mask airway and the administration of 100% oxygen, there was significant contamination of the oropharynx during both PPV and SV. The oropharyngeal concentration of oxygen was high enough to support combustion in a significant number of patients. The use of a laryngeal mask airway does not ensure sealing of the airway and may be one risk factor for an airway fire during adenotonsillectomy.

Effect of reinforced laryngeal mask airway or endotracheal intubation anesthesia on adverse events: quality of life issues for dental patients requiring general sedation

This study tested whether the use of a reinforced laryngeal mask airway (LMA) compared to endotracheal intubation (El) anesthesia diminished adverse events and improved the post-operative quality of life for 146 dental patients who required general anesthesia due to developmental disabilities. In this randomized, crossover trial, patients received either reinforced LMA or El anesthesia during an initial dental treatment visit; the other anesthetic method was used during a second visit scheduled after six months or more. Data were assessed with Student's t-test, chi-square test and McNemar's test to evaluate the affect on quality of life by analyzing disturbances in daily activity, such as eating patterns and sleeping behaviors after the procedure. Although the reinforced LMA anesthesia was associated with a significantly lowered incidence of adverse events (p = .04), neither method significantly disturbed quality of life activities.

A comparison of endotracheal intubation and use of the laryngeal mask airway for ambulatory oral surgery patients

PURPOSE

This study compared current experience with the laryngeal mask airway (LMA) to previous experience with endotracheal intubation for ambulatory patients receiving general anesthesia.

PATIENTS AND METHODS

A retrospective comparison of 157 patients (50 endotracheal intubation [ET] and 107 LMA cases) was conducted. The subjects were American Association of Anesthesiologist (ASA) Class I and II patients who underwent outpatient general anesthesia for dentoalveolar surgery. Procedure time, recovery time, and cost of techniques were compared.

RESULTS

The patients undergoing a variety of outpatient dentoalveolar surgical procedures under general anesthesia in the LMA group had a shorter procedure time than the ET group (40 vs 44 minutes) and had a significantly shorter recovery time (54 vs 67 minutes). In addition, compared with the cost of delivering care with ET, the LMA provided slightly lower cost per case ($20 to $30 per case compared with $35 to $80 per case), depending on the anesthetic technique used. Comparing the 2 techniques for removal of 4 impacted third molars (25 patients ET and 68 patients LMA) revealed a similar procedure time of 39 minutes for both groups, but a shorter recovery time for the LMA group (54 vs 68 minutes).

CONCLUSIONS

Use of the LMA has advantages over endotracheal intubation for outpatients receiving general anesthesia for dentoalveolar surgery.

The submental route revisited using the laryngeal mask airway: a technical note

The submental route for endotracheal intubation is well known and this paper reports the use of the same route for the laryngeal mask airway. This technique can be used whenever it is considered too awkward to perform submental, transoral or transnasal endotracheal intubations. When the surgery has been completed, the mouth is left open to allow the laryngeal mask to be removed; it cannot be left in place in cases of intermaxillary fixation. It is necessary to detach the laryngeal mask orally, never submentally, as it is impossible to remove the mask via the submental route.