PURPOSE: The laryngeal mask airway (LMA) is a supraglottic airway device designed to seal around the laryngeal inlet. A controlled study was designed to compare the effectiveness and complications in inserting the LMA when the cuff is fully deflated and partially inflated. MATERIALS AND METHODS: American Society of Anesthesiologists physical status I or II 172 female patients scheduled for gynecologic procedures were included in this study. Patients were randomly allocated into one of the two groups; fully deflated (n=86) and partially inflated group (n=86). A size #4 LMA was inserted. The number of attempts, time taken for successful insertion, grade of leak, grade of fiberoptic view, and complications were evaluated. RESULTS: All 172 patients completed the study protocol. The number of attempts, time taken for successful insertion, and grade of leak were not significantly different between the two groups. The grade of fiberoptic view and complications were lower in the fully deflated group. CONCLUSION: The fully deflated method is more accurate and safe because of better fiberoptic view and lesser complications than the partially inflated group.
Adult ; Airway Management/adverse effects/instrumentation/*methods ; Female ; Humans ; Laryngeal Masks/*adverse effects ; Middle Aged

INTRODUCTION: Laryngeal mask airway (LMA), which is used in difficult airway maintenance conditions during emergencies, is rarely used in prolonged surgery despite its advantages over endotracheal tube (ETT). In this study, we conducted a comparative analysis of intraoperative gas exchanges between second-generation LMA and ETT during prolonged laparoscopic abdominal surgery. METHODS: Prolonged surgery was defined as a surgery lasting more than 2 h. In total, 394 patients who underwent laparoscopic liver resection via either second-generation LMA or ETT were retrospectively analysed. The following parameters were compared between the two groups of patients: end-tidal pressure of carbon dioxide (ETCO₂), tidal volume (TV), respiratory rate (RR), peak inspiratory pressure (PIP), arterial partial pressure of carbon dioxide (PaCO₂), pH and ratio of arterial partial pressure of oxygen to fractional inspired oxygen (PFR) during surgery. In addition, the incidence of postoperative pulmonary complications (PPCs), including pulmonary aspiration, was compared. RESULTS: The values of ETCO₂, TV, RR and PIP during pneumoperitoneum were comparable between the two groups. Although PaCO₂ at 2 h after induction was higher in patients in the LMA group (40.5 vs. 38.5 mmHg, P < 0.001), the pH and PFR values of the two groups were comparable. The incidence of PPC was similar. CONCLUSION During prolonged laparoscopic abdominal surgery, second-generation LMA facilitates adequate intraoperative gas exchange and may serve as an alternative to ETT.
Humans ; Laryngeal Masks ; Carbon Dioxide ; Retrospective Studies ; Intubation, Intratracheal ; Laparoscopy/adverse effects* ; Postoperative Complications/etiology* ; Oxygen

BACKGROUNDHigh intracuff pressure can cause severe pharyngeal complications including sore throat or hoarseness after laryngeal mask airway (LMA) removal postoperatively. Though the application of minimum effective cuff inflating volume is suggested to maintain airway sealing and adequacy of ventilation for patients receiving general anesthesia with LMA at lower level of the intracuff pressure, it is currently not a standard care in most of the anesthetic departments. In this study, the minimum effective cuff inflating volume was determined for classic LMA Well Lead™ (Well Lead Medical Co., Ltd., China) and its impact on postoperative pharyngeal complications was also explored.

METHODSPatients with American Society of Anesthesiologists physical status (I-III) undergoing the short-duration urological surgery were recruited in this trial. First, the minimum effective cuff inflating volume was determined for size 4 or 5 LMA Well Lead in the study 1. Immediately following placement and confirmation of ideal LMA position, the cuff was inflated with 5, 7, 10 ml of air and up to 30 ml at 5 ml increment. The intracuff pressure, oropharyngeal leak pressure (OLP), and inspiratory peak airway pressure under positive pressure ventilation at the corresponding cuff volume as indicated above were recorded. Second, the enrolled patients were randomly allocated into minimum effective cuff inflating volume group (MC) and routine care (RC) group in the study 2. The minimum effective cuff inflating volume was applied and maintained in MC group, whereas the cuff volume was inflated with half of the maximum cuff inflating volume recommended by manufacturer in RC group throughout the surgical procedure and stay in postanesthesia care unit prior to LMA removal. The incidence of pharyngeal complications at 0, 2, 24, and 48 h after removal of LMA and other intra-operative adverse events were also documented.

RESULTSThe intracuff pressure varied with the cuff inflating volume in a positive linear correlation manner (Y = 11.68X - 42.1, r(2) = 0.9191) under the range of 5-30 ml for size 4 LMA. In similar with size 4 LMA, the data were also showed the linear relationship between the intracuff pressure and the cuff inflating volume (Y = 7.39X - 10.9, r(2) = 0.8855) for size 5 LMA. The minimal effective cuff inflating volume for size 4 or 5 LMA was 7-9 ml in combination of considering OLP needed to maintain airway sealing during intermittently positive pressure ventilation. The intracuff pressure in MC group was lower compared with RC group (63.0 ± 3.7 vs. 126.4 ± 24.0 cmH2O for size 4 LMA; 55.6 ± 2.4 vs. 138.5± 26.8 cmH2O for size 5 LMA; P < 0.0001). The incidence of pharyngeal adverse events was lower in MC group versus the RC group at 2, 24 h after LMA removal.

CONCLUSIONSThe relationship between the cuff inflating volume and the intracuff pressure for size 4 or 5 LMA Well Lead(TM) is in a linear correlation manner at the range of 5-30 ml. The minimal cuff inflating volume is adequate for satisfactory airway sealing and consequently associated with lower incidence of postoperative pharyngeal complications for LMA Well Lead.™.

Aged ; Female ; Hoarseness ; etiology ; Humans ; Laryngeal Masks ; adverse effects ; Male ; Middle Aged ; Pharyngitis ; etiology ; Pharynx ; surgery ; Postoperative Complications ; etiology

We describe a rare complication of acute unilateral submandibular gland swelling following the use of laryngeal mask airway (LMA) in two patients with otherwise uneventful perioperative airway management. This is likely to be a consequence of the pressure exerted by the airway cuff on the tissues within the submandibular triangle. As this complication is rarely reported, its true incidence may in fact be higher, suggesting a need for greater attention on LMA cuff pressures and degree of cuff inflation. We discuss the presenting clinical features, pathophysiology and utilisation of ultrasonographic confirmation of sialadenopathy, and review the current anaesthetic literature to raise awareness of this unusual and under-reported complication of LMA. This complication can be mitigated by incorporating routine manometric checks and limiting intracuff pressures to < 60 cmH2O, potentially avoiding LMA insertions in patients with sialolithiasis and avoiding the use of nitrous oxide.
Adult ; Anesthetics ; therapeutic use ; Female ; Humans ; Laryngeal Masks ; adverse effects ; Male ; Pressure ; Submandibular Gland ; diagnostic imaging ; pathology ; Ultrasonography

OBJECTIVE: To evaluate the effect of different anesthesia management on clinical outcomes in former prematurely born infants undergoing surgeries for retinopathy of prematurity (ROP). METHODS: In this retrospective study, electronic medical record database was searched for all former prematurely born infants (gestational age < 37 weeks and post conceptual age < 60 weeks) who received ROP surgery under inhalational general anesthesia between November 2016 and October 2018. The patients were divided into two groups based on anesthesia management: laryngeal mask airway (LMA) insertion without intravenous muscle relaxant injection and with pressure support ventilation (LMA group) or airway secured with endotracheal tube (ETT) with intravenous muscle relaxant injection and pressure controlled ventilation (ETT group). Primary outcomes included perioperative adverse events and complications. Extubation time and length of stay after surgery were also recorded. RESULTS: Sixty eight preterm infants in the LMA group and 100 preterm infants in the ETT group were included. The incidence of adverse events during surgery (including airway management change and desaturation) was similar in LMA group and ETT group (4.4% vs. 1.0%, P =0.364). During the early recovery period after surgery, the incidence of difficult extubation (extubation time >30 min) was significantly lower in LMA group compared with ETT group (4.4% vs.15.0%, RR=0.262, 95%CI:0.073－0.942, P=0.029). The incidence of respiratory events was similar between the two groups (20.6% vs. 27.0%, P =0.342). However, the incidence of apnea was significantly lower in the LMA group than in the ETT group (5.9% vs.19.0%, RR=0.266, 95%CI: 0.086－0.822, P =0.015). No significant difference was observed between the LMA group and ETT group in incidences of cardiovascular events (0% vs. 1.0%, P =1.000) and unplanned admission to neonatal intensive care unit (5.9% vs. 7.0%, P=0.774). No airway spasm, re-intubation, aspiration or regurgitation was observed during early recovery. During late recovery after returning to ward, the incidence of adverse events was also similar between the two groups (0% vs. 2.0%, P =0.241). The median (IQR) extubation time was 6 (5, 10) min in LMA group and 10 (6, 19) min in ETT group (P < 0.001). The median length of stay after surgery was significantly shortened in LMA group compared with ETT group [20 (17, 22) hours vs. 22 (17, 68) hours, P =0.002]. CONCLUSION Compared with endotracheal intubation with intravenous muscle relaxant injection, laryngeal mask airway insertion without muscle relaxant could achieve an early extubation, and reduce the incidence of apnea during early recovery period in former prematurely born infants undergoing ROP surgery.
Anesthesia, General/adverse effects* ; Child, Preschool ; Humans ; Infant ; Infant, Newborn ; Infant, Premature ; Intubation, Intratracheal/adverse effects* ; Laryngeal Masks ; Retinopathy of Prematurity/surgery* ; Retrospective Studies

PURPOSE: This randomized, controlled, double-blind study was designed to determine the optimal dose of remifentanil for preventing complications associated with the removal of a laryngeal mask airway (LMA) without delaying emergence. MATERIALS AND METHODS: This study randomly assigned 128 patients to remifentanil effect-site concentrations (Ce) of 0 ng/mL (group R0), 0.5 ng/mL (group R0.5), 1.0 ng/mL (group R1.0), and 1.5 ng/mL (group R1.5) during emergence. The emergence and recovery profiles were recorded. Adverse events such as coughing, airway obstruction, breath-holding, agitation, desaturation, nausea, and vomiting were also evaluated. RESULTS: The number of patients with respiratory complications such as coughing and breath-holding was significantly lower in the R1.0 and R1.5 groups than in the R0 group (p<0.05). Emergence agitation also decreased in the R1.0 and R1.5 groups (p<0.0083). The time to LMA removal was significantly longer in the R1.5 group than in the other groups (p<0.05). CONCLUSION: Maintaining a remifentanil Ce of 1.0 ng/mL during emergence may suppress adverse events such as coughing, breath-holding, and agitation following the removal of LMA without delayed awakening.
Adult ; Airway Management/*methods ; Anesthesia Recovery Period ; Anesthetics, Intravenous/*administration & dosage ; Cough/prevention & control ; Device Removal ; Dose-Response Relationship, Drug ; Double-Blind Method ; Female ; Humans ; Infusions, Intravenous ; Laryngeal Masks/*adverse effects ; Male ; Middle Aged ; Piperidines/*administration & dosage ; Postoperative Complications/prevention & control ; Psychomotor Agitation ; Vomiting/prevention & control

PURPOSE: This randomized, controlled, double-blind study was designed to determine the optimal dose of remifentanil for preventing complications associated with the removal of a laryngeal mask airway (LMA) without delaying emergence. MATERIALS AND METHODS: This study randomly assigned 128 patients to remifentanil effect-site concentrations (Ce) of 0 ng/mL (group R0), 0.5 ng/mL (group R0.5), 1.0 ng/mL (group R1.0), and 1.5 ng/mL (group R1.5) during emergence. The emergence and recovery profiles were recorded. Adverse events such as coughing, airway obstruction, breath-holding, agitation, desaturation, nausea, and vomiting were also evaluated. RESULTS: The number of patients with respiratory complications such as coughing and breath-holding was significantly lower in the R1.0 and R1.5 groups than in the R0 group (p<0.05). Emergence agitation also decreased in the R1.0 and R1.5 groups (p<0.0083). The time to LMA removal was significantly longer in the R1.5 group than in the other groups (p<0.05). CONCLUSION: Maintaining a remifentanil Ce of 1.0 ng/mL during emergence may suppress adverse events such as coughing, breath-holding, and agitation following the removal of LMA without delayed awakening.
Adult ; Airway Management/*methods ; Anesthesia Recovery Period ; Anesthetics, Intravenous/*administration & dosage ; Cough/prevention & control ; Device Removal ; Dose-Response Relationship, Drug ; Double-Blind Method ; Female ; Humans ; Infusions, Intravenous ; Laryngeal Masks/*adverse effects ; Male ; Middle Aged ; Piperidines/*administration & dosage ; Postoperative Complications/prevention & control ; Psychomotor Agitation ; Vomiting/prevention & control