LMA® protector™ in patients undergoing laparoscopic surgeries: a multicenter prospective observational study

Background Laryngeal masks airway (LMA) has been increasingly used in surgical patients. However, the use of LMA in laparoscopic surgeries remains controversial. The major concerns include the potential risk of esophageal regurgitation, aspiration, and difficulties to achieve effective ventilation. The aim of this study was to evaluate the safety and effectiveness of the LMA® Protector™ in patients undergoing laparoscopic surgery. Methods Patients aged 18 to 70 years, scheduled for laparoscopic surgeries were included. The insertion time, successful insertion rate, and oropharyngeal leak pressure were measured. Airway complications and airway manipulations during the procedure were documented. Effective ventilation rate was calculated. Visible bloodstains and reflux content in the drainage channel were documented after the removal of LMA® Protector™. Results Three hundred patients were enrolled. The insertion of LMA® Protector™ failed in seven patients resulting with a successful insertion rate of 97.7%. During the maintenance of anesthesia, airway manipulation was required in 19 patients (19/293, 6.48%), in three of whom the LMA was replaced with endotracheal intubation resulting with an effective ventilation rate of 96.7% (290/300). The oropharyngeal leak pressure was 30.18 ± 5.88 cmH2O. Seventy-five patients (25.86%) reported mild sore throat on the first day after surgery. Bloodstains on study devices were noticed in 58 patients (20%). Seventy-five patients (25.86%) reported mild sore throat on the first day after surgery. Gastric reflux was noticed in the drainage tube in 5 patients (1.72%) with no signs of aspiration in any of those patients. Conclusions The LMA® Protector™ was shown to be safe and effective in patients undergoing laparoscopic surgeries. Although minor complications that require no further treatment, no clinically diagnosed aspiration was noticed in our study. Gastric reflux was noticed in the drainage tube in five patients undergoing laparoscopic gynecology surgery. Further research is needed to verify whether LMA® Protector™ is suitable for procedures in Trendelenburg position or other situations that a high risk of gastroesophageal reflux exists. Trial registration The trial was registered at the Chinese Clinical Trial Registry (ChiCTR1800018300, date of registration: September 2018).

Success of placement and complications during v-gel placement and maintenance of anaesthesia

Objectives Airway management during anaesthesia in cats is always a demanding task and is associated with several complications. The aim of this study was to evaluate the practicability and complications during feline-specific laryngeal mask placement in anaesthetised cats as an alternative to endotracheal intubation. Methods In this prospective clinical study, laryngeal masks were placed in 148 anaesthetised cats. Success of placement was evaluated by capnography. Results Placement was possible at the first attempt in 136 cats, at the second attempt in eight cats and at the third attempt in one cat. In one cat, placement was not possible. Two cats were excluded. Failure to position the laryngeal mask at the first attempt was not different between laryngeal mask sizes ( P = 0.313) or positioning during placement ( P = 0.406). In nine cats, the laryngeal mask dislocated during the procedure. Dislocation occurred more often in the dorsal position than in the sternal ( P = 0.018) and right lateral positions ( P = 0.046). Mucous obstruction of the laryngeal mask occurred in one of these cats and regurgitation in another. Material-related issues, such as disconnection of the parts of the laryngeal mask and leakage of the balloon, were observed in 2/8 laryngeal masks. Conclusions and relevance The placement of a feline-specific laryngeal mask was easy to perform. In about 7% of the cases, replacement of the device was required due to mispositioning or dislocation. Full monitoring, including capnography, should be provided to uncover dislocation and airway obstruction immediately.

LMA ® Protector™ In Patients Undergoing Laparoscopic Surgeries: A Multicenter Prospective Observational Study

Backgroundː Laryngeal masks airway (LMA) has been increasingly used in surgical patients. However, the use of LMA in laparoscopic surgeries remains controversial. The major concerns include the potential risk of esophageal regurgitation, aspiration, and difficulties to achieve effective ventilation. The aim of this study was to evaluate the safety and effectiveness of the LMA® Protector™ in patients undergoing laparoscopic surgery. Methodsː Patients aged 18 to 70 years, scheduled for laparoscopic surgeries were included. The insertion time, successful insertion rate, and oropharyngeal leak pressure were measured. Airway complications and airway manipulations during the procedure were documented. Effective ventilation rate was calculated. Visible bloodstains and reflux content in the drainage channel were documented after the removal of LMA® Protector™. Resultsː A total of 300 patients were enrolled. The insertion of LMA® Protector™ failed in seven patients resulting with a successful insertion rate of 97.7%. During the maintenance of anesthesia, airway manipulation was required in 19 patients (19/293, 6.48%), in three of whom the LMA was replaced with endotracheal intubation resulting with an effective ventilation rate of 96.7% (290/300). The oropharyngeal leak pressure was 30.18±5.88 cmH2O. 75 patients (25.86%) reported mild sore throat on the first day after surgery. No signs of aspiration were noticed in any of those patients. Conclusionsː The LMA® Protector™ was shown to be safe and effective in patients undergoing laparoscopic surgeries. Although minor complications that requiring no further treatment, no clinically diagnosed aspiration was noticed in our study. Trial registration: The trail was registered at the Chinese Clinical Trial Registry (ChiCTR1800018300, data of registration, September 2018).

Safety and Efficacy of a Novel Intubating Laryngeal Mask during the recovery period following Supratentorial Tumour Surgery

Objective To assess safety and efficacy of a novel intubation laryngeal mask airway (ILMA) during the recovery period following supratentorial tumour surgery. Methods Patients who underwent supratentorial tumour surgery at our centre from January 2012 to December 2016 were eligible for this prospective randomised, parallel group study. We developed a novel ILMA using closely fitting laryngeal masks (No. 4/5) with 7.0/7.5 mm endotracheal tubes (ETT) plus screw fixators and anti-pollution sleeves. Results In total, 100 patients were intubated with the novel ILMA and 100 the ETT. There were no differences between groups in haemodynamic variables, oxygen saturation, exhaled CO2, or bispectral index all recorded during the 72-hour recovery period. However, there were significantly fewer incidences of coughing, less fluid drainage and lower haemoglobin levels in surgical fluid in the ILMA group compared with the ETT group. Conclusion Our novel ILMA device was associated with reduced coughing, fluid drainage and blood in surgical drain during the recovery period following supratentorial tumour surgery.

Recovery room procedures

Airway protection, laryngeal masks, and intubation are described as well as gas delivery circuits. Emergency equipment required for reintubation, and the technique for this procedure, are outlined. Instructions for intravenous and intramuscular injections are clearly explained.

Correlation and variation of cuff inflating volumes and pressures in different adult models of laryngeal mask: a prospective randomized trial

Background: Hyperinflation of laryngeal mask cuffs may carry the risk of airway complications. The manufacturer recommends inflating cuff until the intracuff pressure reaches 60 cmH2O, or inflate with the volume of air to not exceed the maximum recommended volume. We prospectively assessed the correlation of cuff inflating volumes and pressures, and the appropriated the cuff inflating volumes to generate an intracuff pressure of 60 cmH2O in the adult laryngeal masks from different manufacturers. Methods: Two groups of eighty patients requiring laryngeal mask size 3 and 4 during general anesthesia were randomized into 4 subgroups for each size of the laryngeal mask: Soft Seal® (Portex®), AuraOnceTM (Ambu®), LMA-ClassicTM (Teleflex®) and LMA-ProSealTM (Teleflex®). After insertion, the cuff was inflated with 5-ml increments of air up to the maximum recommended volume. After each 5-ml intracuff pressure was measured, the volume of air that generated the intracuff pressure of 60 cmH2O was recorded. Results: Mean(SD) volume of air required to achieve the intracuff pressure of 60 cmH2O in Soft Seal®, AuraOnceTM, LMA-ClassicTM, LMA-ProSealTM laryngeal mask size 3 were 11.80(1.88), 9.20(1.88), 8.95(1.50) and 13.50(2.48) ml, respectively, and these volumes in laryngeal mask size 4 were 14.45(4.12), 12.55(1.85), 11.30(1.95) and 18.20(3.47) ml, respectively. The maximum recommended volume resulted in high intracuff pressures (>60 cmH2O) in all laryngeal mask types and sizes studied. Conclusion: Pressure-volume curves of adult laryngeal masks are all in sigmoidal shape. Cuff designs and materials can effect pressure and volume correlation. Approximately half of the maximum recommended volume is required to achieve the intracuff pressure of 60 cmH2O except LMA-ProSealTM which required two-thirds of the maximum recommended volume. Trial registration: Thai Clinical Trials Registry, TCTR20150602001, May 28, 2015

Systematic review and meta-analysis comparing ventilatory support in chemical, biological and radiological emergencies

Objective: to compare the mean development time of the techniques of direct laryngoscopy and insertion of supraglottic devices; and to evaluate the success rate in the first attempt of these techniques, considering health professionals wearing specific personal protective equipment (waterproof overalls; gloves; boots; eye protection; mask). Method: meta-analysis with studies from LILACS, MEDLINE, CINAHL, Cochrane, Scopus and Web of Science. The keywords were the following: personal protective equipment; airway management; intubation; laryngeal masks. Results: in the “reduction of the time of the procedures” outcome, the general analysis of the supraglottic devices in comparison with the orotracheal tube initially presented high heterogeneity of the data (I2= 97%). Subgroup analysis had an impact on reducing heterogeneity among the data. The “laryngeal mask as a guide for orotracheal intubation” subgroup showed moderate heterogeneity (I2= 74%). The “2ndgeneration supraglottic devices” subgroup showed homogeneity (I2= 0%). All the meta-analyses favored supraglottic devices. In the “success in the first attempt” outcome, moderate homogeneity was found (I2= 52%), showing a higher proportion of correct answers for supraglottic devices. Conclusion: in the context of chemical, biological or radiological disaster, the insertion of the supraglottic device proved to be faster and more likely to be successful by health professionals. PROSPERO record (CRD42019136139).

Laryngeal mask versus endotracheal intubation for pre-hospital emergency airway management: a meta-analysis of randomized control studies

Background : Pre-hospital emergency airway management plays an important role in pre-hospital care. Laryngeal masks are increasingly employed for the airway management of pre-hospital critical patients and have achieved promising results. Although several randomized controlled trials have reported benefits, the efficacy of laryngeal masks in pre-hospital emergency airway management compared to endotracheal intubation have not been systematically reviewed. Methods: Electronic databases (PubMed, Cochrane Library, Embase, Scopus and CNKI) were searched up to April 2019 for related randomized studies. Outcome indicators included overall intubation success rates, the success rates of the first intubation, insertion time, resuscitation efficiency rates, SpO2 rise time, the blood gas index and adverse events. Two investigators selected the trials, extracted the data according to inclusion and exclusion criteria, and assessed the quality of the literature according to the Jada score. The meta-analysis was performed using stata14.0 software. Results: We included 31 human studies. Compared to endotracheal intubation, the application of laryngeal mask for pre-hospital emergencies enhanced the resuscitation efficiency rates [RR=1.20, 95% CI (1.06, 1.35), P<0.001], improved the success of first intubation [RR=1.29, 95% CI (1.18, 1.40), P<0.001] and the patients’ blood gas index, shortened the insertion and SpO2 rise times [SMD=-3.48, 95% CI (-4.17, -2.80), P < 0.001; -2.19, 95% CI (-3.06, -1.32), P < 0.001] and reduced the incidence of adverse events [RR=0.41, 95% CI (0.30, 0.57, P<0.001]. All results were stable and statistically significant. Conclusions: Laryngeal masks could quickly and effectively improve patient ventilation in pre-hospital emergencies, highlighting its utility for clinical application.