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

The effects of laryngeal mask versus endotracheal tube on atelectasis after general anesthesia induction assessed by lung ultrasound: A randomized controlled trial

STUDY OBJECTIVE

This study aims to evaluate the impact of Supreme™ laryngeal masks versus endotracheal tubes on atelectasis during general anesthesia using lung ultrasound (LUS), and provide evidence for respiratory management.

DESIGN

A single-center, double-blind, randomized controlled trial was conducted.

SETTING

The study was conducted in both the operating room and the post-anesthesia care unit, with follow-up assessments performed in the ward.

PATIENTS

Enrollment included 180 cases undergoing non-laparoscopic surgeries in gynecology, urology, and orthopedic limb surgeries.

INTERVENTIONS

Patients were randomly assigned 1:1 to the endotracheal intubation or laryngeal mask group.

MEASUREMENTS

LUS scores were recorded across 12 lung regions at baseline, 15 min after airway establishment, at the end of surgery, and 30 min following airway removal. Outcome measures encompassed the oxygenation index, dynamic lung compliance, incidence of postoperative pulmonary complications, throat pain, and other postoperative complications assessed at 24 and 48 h postoperatively. The primary outcome focused on the LUS score in all 12 lung regions at 15 min after airway establishment.

MAIN RESULTS

Intention-to-treat analysis of 177 subjects revealed endotracheal intubation led to significantly higher LUS scores at 15 min {P < 0.001, mean difference 4.15 ± 0.60, 95% CI [2.97, 5.33]}, end of surgery (P < 0.001, mean difference 3.37 ± 0.68, 95% CI [2.02, 4.72]), and 30 min post-removal (P < 0.001, mean difference 2.63 ± 0.48, 95% CI [1.68, 3.58]). No major complications occurred in the two groups.

CONCLUSIONS

Compared to endotracheal intubation, laryngeal masks effectively reduce atelectasis formation and progression in gynecological, urological non-laparoscopic, and orthopedic limb surgeries. However, caution is warranted when generalizing these findings to surgeries with a higher risk of laryngeal mask leakage or obese patients. Additionally, the efficacy of laryngeal masks in reducing postoperative atelectasis remains uncertain when comprehensive monitoring of muscle relaxation and reversal therapy is employed.

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.

Comparison of lidocaine viscous gargle and topical application on laryngeal mask airway in general anesthesia: A randomized clinical trial

OBJECTIVES

To investigate the effects and safety of lidocaine viscous gargle on postoperative sore throat (POST) in patients receiving a laryngeal mask airway (LMA) in general anesthesia.

METHODS

In this randomized controlled trial, 90 patients undergoing urological surgery were allocated into 2 treatment arms (n=45): lidocaine viscous gargle before LMA insertion (Group G) and topical application of lidocaine viscous on the LMA (Group T). Outcome data were collected before placement of LMA (T0), after insertion of LMA (T1), immediately (T2), one hour (T3), and 24 hours after removal of LMA (T4). We analyzed the incidence of POST, pharynx dryness, and adverse events.

RESULTS

The incidence of POST was lower in Group G than Group T at T2 (11.1% vs. 28.9%; p=0.063), T3 (11.1% vs. 24.4%; p=0.167), and T4 (2.2% vs. 4.4%; p=0.566), but there was no significant difference between groups. No patient in either group experienced severe pain or treatment-related adverse events. There was a significantly lower incidence of pharynx dryness in Group G than Group T (p<0.05) at T2, T3, and T4.

CONCLUSION

Lidocaine viscous gargle showed no statistically significant difference in incidence of POST and incidence of pharynx dryness compared with topical application of lidocaine on the LMA. Both approaches were safe for patients receiving LMA.Chinese Clinical Trial Register No.: ChiCTR2200059720.

Evaluation of Four Techniques to Administer Laryngeal Mask Airway

Background

Laryngeal mask airway (LMA) plays a crucial role in the field of modern anesthesia. There are different techniques to administer LMA. Here we aimed to compare the four methods of standard, 90° rotation, 180° rotation, and thumb placement in LMA mast placement.

Materials and Methods

This is a clinical trial that was performed on 257 candidates of elective surgical operations requiring general anesthesia. All patients were categorized into four groups of LMA placement with index finger (standard method), mask placement with 90° rotation, 180° rotation method, and thumb finger group. We collected data regarding the success rates of LMA placement, the need for any manipulation when placing the mask, LMA placement time, failure of mask placement, presence of blood on the LMA, and laryngospasm and sore throats 1 hour after surgery in patients.

Results

The 90° rotation method had a significantly higher first attempt success rate than that in the other three methods (98.4%, P = 0.02). Total success rate in 90° rotation method was also significantly higher than the other techniques (100%, P < 0.001). The need for any manipulation when placing the mask (1.6%, P = 0.01), presence of blood on the LMA mask (1.6%, P = 0.33), and frequency of sore throats 1 hour after surgery (21.9%, P = 0.14) were also lower in 90° rotation method than that in the other methods.

Conclusion

The 90° rotation method had significantly higher success rate and lower failure rate regarding the mask placement compared to other three methods.

Wooden Disposable Tongue Depressor: Can Facilitate Appropriate Reinforced Laryngeal Mask Insertion? A Randomized Controlled Trial

Background: The reinforced laryngeal mask airway (RLMA) is difficult to insert due to the flexibility of its inner armored shaft. Many authors agreed that the available techniques have some disadvantages. They use materials that are reusable and require resterilization but may not guarantee infection control particularly during pandemics. The standard method can cause contamination and prone the operator to unanticipated trauma to their finger during placement. So this study aimed to evaluate the usefulness of disposable tongue depressors to aid insertion of the reinforced laryngeal mask airway. Methods: A randomized controlled trial included one hundred ninety-four adult patients of either gender American Society of Anesthesiologists (ASA) I and II attended for elective day case surgery under general anesthesia. Patients were randomly categorized into two groups; each group consisted of ninety-seven. In the first group, insertion of the reinforced laryngeal mask airway was done using the standard technique of digital manipulation whereas the second one is the study group where disposable wooden tongue depressor guided insertion was used. The data were analyzed using SPSS version 23. Data were presented as frequencies or means and standard deviations. Chi-Square, Fisher Exact, and t-test were used. P value < 0.05 was considered significant. Results: No significant difference in basic patients' demographic, anthropometric, and clinical characteristics were noticed between the two groups. The insertion time as well as the total time for RLMA placement, was significantly shorter in the new method group. Trauma was significantly less than 2.1% in the new method group compared to the standard group 10.3%, p=0.003). Conclusion: The disposable wood tongue depressor insertion technique helps facilitate the correct placement of the reinforced laryngeal mask airway.

Efficacy and Safety of Flexible Laryngeal Mask Ventilation in Otologic Surgery: A Retrospective Analysis

Background

Flexible laryngeal mask airways (FLMAs) ventilation have been widely used as airway devices during general anesthesia, especially in otologic surgery. However, the current literature reports that the clinical success and failure rates for FLMA usage are quite different, and there remains a paucity of data regarding factors associated with FLMA failure and complications related to FLMA usage.

Purpose

To evaluate the success and failure rates of FLMA usage in otologic surgery, the factors associated with FLMA failure and complications related to FLMA usage.

Patients and Methods

All patients who underwent otologic surgery, including middle ear and mastoid procedures, under general anesthesia at a large tertiary general hospital from 2015 to 2019 were reviewed. The primary outcome was the FLMA failure rate, defined as any airway event requiring device removal and tracheal intubation, including primary and secondary failure. The secondary outcomes were specific clinical factors, including patient sex, age, weight, American Society of Anesthesiologists (ASA) classification, body mass index (BMI) and duration of surgery, which were analyzed as related risk factors.

Results

Among 5557 patients with planned FLMA use, the final success rate was 98.5%. Sixty-seven percent of the failures occurred during initial introduction of the FLMA, 8% occurred after head and neck rotation, and 25% occurred during the procedures. Two independent clinical factors associated with FLMA failure were male sex and age. Respiratory complications were observed in 0.61% of patients, and the rate of severe nerve and tissue damage associated with FLMA use was 0.05.

Conclusion

This study demonstrates a high success rate of 98.5% for FLMA use in adults undergoing otologic surgery with rare adverse airway events and injuries complications. Two independent risk factors require attention and thorough and accurate management is necessary for every clinician.

Airway management in general anesthesia for endovascular treatment of cerebral arteriovenous malformation: a retrospective observational study

Background and objective

This retrospective and observational study aimed to retrospectively evaluate the use of the endotracheal tube (ETT) and the Laryngeal Mask Airway (LMA) for the airway management with respect to airway safety, hemodynamic stability, adverse respiratory events, and recovery characteristics in patients who underwent endovascular treatment (EVT) for cerebrovascular arteriovenous malformation under general anesthesia between 2011 and 2018.

Methods

The study included data from the patient's electronic medical records and anesthesia files. The primary outcome measure was the incidence of hemodynamic disturbances and respiratory adverse events during airway management. The secondary outcome measure was the comparison of recovery characteristics.

Results

The airway was secured using ETT in 41 patients and LMA in 39 patients. Airway safety was established in all patients without a complication throughout the procedure. Mean arterial blood pressure and heart rate were increased to > 20% of baseline levels at intubation and extubation periods in more patients in the ETT group than the LMA group (27 vs. 3; p = 0.07, and 11 vs. 2; p = 0.021). Respiratory adverse events including straining and coughing were observed in ten patients in the ETT group but only in one patient in the LMA group (p = 0.013). Time to extubation, to neurological assessment, and to discharge from the angiography unit were similar (p > 0.05).

Conclusion

It was concluded that LMA provided sufficient airway safety as with ETT and may be used as an alternative to ETT for EVTs under general anesthesia.

Various Uses of Laryngeal Mask Airway during Tracheal Surgery

BACKGROUND

 The use of laryngeal mask airway (LMA) ventilation in surgeries to be performed in upper tracheal stenosis has been reported in the case series. However, there is no generally accepted standardized approach for the use of LMA. In this study, LMA usage areas and advantages of trachea surgery were examined.

METHODS

 The records of 21 patients who underwent tracheal surgery using LMA ventilation between March 2016 and May 2020 were evaluated retrospectively. The patient data were analyzed according to age, gender, mean follow-up time, surgical indication, mean tracheal resection length, anastomosis duration, mean oxygen saturation, mean end-tidal CO₂ levels, and postoperative complications.

RESULTS

 Four patients were female and 17 were male, their median age was 43 (11-72 range) and the mean follow-up time was 17.6 months. The most common surgical indication was postintubation tracheal stenosis. The mean tracheal resection length was 26.6 mm and the mean anastomosis duration was 11.3 minutes. The mean pulse oximetry and mean end-tidal CO₂ during laryngeal mask ventilation was 97.6% ± 2.1 and 38.1 ± 2.8 mm Hg, respectively. Postoperative complications were higher in patients with comorbidities.

CONCLUSION

 LMA-assisted tracheal surgery is a method that can be used safely as a standard technique in the surgery of benign and malignant diseases of both the upper and lower airway performed on pediatric patients, patients with tracheostomy, and suitable patients with tracheoesophageal fistula.

The impact of topical lidocaine and timing of LMA removal on the incidence of airway events during the recovery period in children: a randomized controlled trial

Background

The timing of laryngeal mask airway (LMA) removal remains undefined. This study aimed to assess the optimal timing for LMA removal and whether topical anesthesia with lidocaine could reduce airway adverse events.

Methods

This randomized controlled trial assessed one-to-six-year-old children with ASA I-II scheduled for squint correction surgery under general anesthesia. The children were randomized into the LA (lidocaine cream smeared to the cuff of the LMA before insertion, with mask removal in the awake state), LD (lidocaine application and LMA removal under deep anesthesia), NLA (hydrosoluble lubricant application and LMA removal in the awake state) and NLD (hydrosoluble lubricant application and LMA removal in deep anesthesia) groups. The primary endpoint was a composite of irritating cough, laryngeal spasm, SpO₂ < 96%, and glossocoma in the recovery period in the PACU. The secondary endpoints included the incidence of pharyngalgia and hoarseness within 24 h after the operation, duration of PACU stay, and incidence of agitation in the recovery period. The assessor was unblinded.

Results

Each group included 98 children. The overall incidence of adverse airway events was significantly lower in the LA group (9.4%) compared with the LD (23.7%), NLA (32.6%), and NLD (28.7%) groups (P=0.001). Cough and laryngeal spasm rates were significantly higher in the NLA group (20.0 and 9.5%, respectively) than the LA (5.2 and 0%, respectively), LD (4.1 and 1.0%, respectively), and NLD (9.6 and 2.1%, respectively) groups (P=0.001). Glossocoma incidence was significantly lower in the LA and NLA groups (0%) than in the LD (19.6%) and NLD (20.2%) groups (P< 0.001). At 24 h post-operation, pharyngalgia incidence was significantly higher in the NLA group (15.8%) than the LA (3.1%), LD (1.0%), and NLD (3.2%) groups (P< 0.001).

Conclusions

LMA removal in the awake state after topical lidocaine anesthesia reduces the incidence of postoperative airway events.

Trial registration

ChiCTR, ChiCTR-IPR-17012347. Registered August 12, 2017.

Effects of Peak Inspiratory Pressure-Guided Setting of Intracuff Pressure for Laryngeal Mask Airway Supreme™ Use during Laparoscopic Cholecystectomy: A Randomized Controlled Trial

PURPOSE

To determine the effects of peak inspiratory pressure (PIP)-guided intracuff pressure (ICP) modulation of laryngeal mask airway (LMA) Supreme™ during laparoscopic cholecystectomy.

METHODS

Totally 120 patients were randomly divided using computer-generated numbers into a control group (n = 60; ICP, 60 cmH₂O) and a PIP group (n = 60), in which ICP was increased with 5 cmH₂O each time from PIP level until no air leaks from the oropharynx. PIP, ICP, cuff volume (CV), oropharyngeal leak pressure (OLP) and leak fraction (LF) were recorded before and after pneumoperitoneum establishment. Postoperative pharyngolaryngeal complications (sore throat, dysphagia, pharyngeal hematoma, and dysphonia) were also recorded.

RESULTS

Demographic data were similar in the two groups. The CV and ICP before and after pneumoperitoneum were significantly lower in the PIP group (CV: 15.6 ± 2.3 mL and 21.0 ± 2.6 mL; ICP: 14.3 ± 2.9 cmH₂O and 20.5 ± 3.4 cmH₂O) than in the control group (CV: 33.0 ± 2.8 mL and 32.8 ± 1.9 mL; ICP: 60.0 ± 0.1 cmH₂O and 60.0 ± 0.1 cmH₂O) (P < 0.05). Although OLP was lower in the PIP group (P < 0.05), the LF was similar in the two groups (P > 0.05). There were fewer postoperative pharyngolaryngeal complications in the PIP group (P < 0.05).

CONCLUSIONS

Compared with a fixed ICP of 60 cmH₂O, PIP-guided ICP modulation during LMA Supreme™ use provided effective airway sealing at a lower CV and ICP, and produced fewer postoperative pharyngolaryngeal complications in patients undergoing laparoscopic cholecystectomy.

Comparison of the Baska and I-gel supraglottic airway devices: a randomized controlled study

BACKGROUND

Laryngeal masks are increasingly used in place of endotracheal intubation or face masks for maintaining the airway during surgery.

OBJECTIVES

Compare the insertion time and other features of the Baska and I-gel masks in patients undergoing general anesthesia for urological surgery.

DESIGN

Randomized-controlled, single-blind study.

SETTINGS

Urology surgical operating rooms of a tertiary care hospital.

SUBJECTS AND METHODS

We enrolled concomitant patients whose surgery was expected to last less than two hours. Following premedication and adequate relaxation, subjects were randomly allocated to the I-gel mask or the Baska mask. Computer-generated random numbers were used for randomization with sealed opaque envelopes for allocation concealment.

MAIN OUTCOME MEASURES

The primary outcome measure of the study was the time required for laryngeal mask airway (LMA) insertion. Also, the number of device placement attempts, the number of postoperative signs and symptoms (cough, breath holding, laryngeal spasm, lip trauma, blood on the mask), and laryngopharyngeal morbidity scores at 1 and 24 hours postoperatively.

SAMPLE SIZE

211 met inclusion criteria, 200 participants completed the study.

RESULTS

Compared to I-gel, the Baska mask required a longer time for insertion, and its airway pressure was higher. The median (minimum-maximum) duration of LMA insertion in the Baska and I-gel groups was 14 (6-25) and 7 (5-12) seconds, respectively (z=-10.934; P<.001). The mean (SD) airway pressures were significantly different between the two groups (15.8 [1.9] and 14.9 [1.7] cm/H2O for Baska and I-gel, respectively; t=3.668; P<.001). Seal pressure was not significantly different between the groups (0.08 [0.2] vs. 0.07 [0.2] cm/H2O in the Baska and I-gel groups, respectively, (t=1.35; P=.194).

CONCLUSIONS

The Baska and I-gel masks are similar in most respects. Both have reasonably acceptable insertion times and can be used for selected surgical procedures.

LIMITATIONS

The requirement for more vigorous training is a limitation of the Baska mask. Results could differ with patients younger than 18 years of age or obese patients.

CONFLICT OF INTEREST

None.

CLINICAL TRIAL REGISTRY

Not registered.

Comparing the insertion and ventilation of laryngeal mask airway according to the patient's head position and muscle relaxation use. A prospective clinical trial

OBJECTIVES

To assess the insertion and ventilation of the laryngeal mask airway (LMA) classic while using different head positions with or without muscle relaxant.

METHODS

This is a double-blind randomized clinical trial. Patients scheduled for ureteral calculus surgery at Shanghai General Hospital, Shanghai, China were recruited between November 2017 and November 2018. A total of 132 adults were consecutively selected. Patients were randomly divided into 4 groups according to head positioning and muscle relaxant use. An 8-cm-high pillow was used to achieve the sniffing position. The insertion time, initial peak pressure (Ppeak), mean pressure (Pmean) of the airway during intermittent positive pressure ventilation (primary endpoint) and fiberoptic score of the LMA position (secondary endpoint) were evaluated via electronic bronchoscopy through the mask bar. All adverse events were recorded. Results: Data were analyzed by ANOVA, 2-way ANOVA, Chi-squared, Cochran-Mantel-Haenszel, and Kruskal-Wallis tests. The insertion time required for the first attempt, fiberoptic score, Ppeak and Pmean did not differ among the groups. However, the incidence of adverse events in groups not using muscle relaxant was higher than in those using muscle relaxant. Conclusion: Use of a sniffing position and muscle relaxant slightly eased the insertion of the LMA but did not affect the fiberoptic score or ventilation parameters. Using a muscle relaxant, but not the sniffing position, reduced the incidence of adverse effects.

Anesthetic Management of a Down Syndrome Patient with Subocclusive Syndrome

The present study aims to describe the anesthetic management of a patient with Down syndrome in connection to the degree of difficulty in orotracheal intubation and the associated risks of general anesthesia. The established diagnosis was subocclusive syndrome, requiring an emergent surgical intervention. Preoperatively, the patient was stabilized, and secondly, a series of clinical and paraclinical investigations were carried out in order to assess the best management of the anesthetic procedure. Risk factors were identified, including ischemic heart disease, grade II obesity, hyperglycemia, patient's old age and marked mental retardation. The results of examinations that were carried out showed that the degree of difficulty of orotracheal intubation was low. Finally, the preoperative assessment indicated that the most appropriate approach for this patient was to perform a general anesthesia with endotracheal intubation. However, special care was given to the anesthetic and postoperative condition of the patient in order to lower the possible complications of the surgical intervention.