The ProSeal™ Laryngeal Mask Airway is an Effective Alternative to Laryngoscope-Guided Tracheal Intubation for Gynaecological Laparoscopy

Proseal laryngeal mask airway and endotracheal intubation in lower abdominal gynecological surgeries for perioperative gastric volume assessment and assessing postoperative recovery of gastrointestinal functions: A randomized controlled trial

Background

In the context of perioperative care, the concern of gastric content aspiration during surgical procedures is crucial, though relatively rare. Supraglottic devices after the creation of pneumoperitoneum and positive pressure ventilation may cause gastric insufflation. This study explores the unique aspects of antral cross-sectional area (CSA) measurement as a novel indicator in comparing the use of ProSeal laryngeal mask airway (LMA) and endotracheal intubation in airway management during lower abdominal surgeries and assessing postoperative recovery in both the groups.

Methods

The study commenced after obtaining approval from Institutional Ethical Committee (IEC number-AIIMS/IEC/22/251 Date: 27/05/2022) and after registration in Clinical Trials Registry - India (CTRI) (CTRI/2022/07/044102 Registered on: 18/07/2022) and was conducted from August 2022 to August 2023. A total of 72 ASA I and II participants were included in two groups: endotracheal tube (ETT) (Group E) and PLMA (Group P). The primary outcome was the antral CSA, and secondary outcomes included hemodynamic and respiratory parameters, time to start clear fluid, light diet, and length of stay.

Results

Our results showed that there was no statistically significant difference between the two groups in antral CSA at various time intervals. The hemodynamic variables were significantly higher in the endotracheal tube group (P < 0.0001). The absence of significant differences in time to start clear liquids, time to start a light diet, and time to achieve bowel movements between the ETT and PLMA groups suggested that both airway management techniques are equally safe in facilitating postoperative recovery concerning gastrointestinal functions.

Conclusions

Patients who underwent minimally invasive lower abdominal surgeries, choice of airway management technique, whether ETT or PLMA, did not substantially impact antral CSA, vital parameters, respiratory parameters, or postoperative recovery.

Supraglottic Airway Devices with Vision Guided Systems: Third Generation of Supraglottic Airway Devices

Supraglottic airway devices are currently widely used for airway management both for anaesthesia and emergency medicine. First-generation SADs only had a ventilation channel and did not provide protection from possible aspiration of gastric content if regurgitation occurred. Second-generation SADs are equipped with a gastric channel to allow the insertion of a gastric catheter and suctioning of gastric content. Additionally, the seal was improved by a change in the shape of the cuff. Some second-generation SADs were also designed to allow for intubation through the lumen using fiberscopes. Although the safety and efficacy of use of SADs are very high, there are still some issues in terms of providing an adequate seal and protection from possible complications related to misplacement of SAD. New SADs which allow users to choose the insertion scope and control the position of SAD can overcome those problems. Additionally, the Video Laryngeal Mask Airway may serve as an endotracheal intubation device, offering a good alternative to fibre-optic intubation through second-generation SADs. In this narrative review, we provide knowledge of the use of video laryngeal mask airways and the possible advantages of introducing them into daily clinical practice.

New techniques of regional anaesthesia for renal laparoscopic surgeries

Renal procedures are performed within the realm of urology, general and transplant surgery. The implementation of new operating techniques imposes on anaesthetists the need to adapt their methods, aiming to improve the patient's perioperative comfort and safety. Laparoscopy is gaining increasing interest as a less invasive procedure; however clinical research shows that pain after the procedure is underestimated and therefore poorly controlled. Multimodal analgesia is very promising, though, as it allows better pain control, expedites discharge and enhances recovery. This is achieved through a combination of general and regional anaesthesia with administration of adjuvant drugs intraoperatively, resulting in reduced opioid requirements in the recovery room with diminished side effects of pain treatment. Good communication between the surgeon and the anaesthetist is the key to effective anaesthesia and analgesia.

Comparison of airway management without neuromuscular blockers in laparoscopic gynecological surgery

New generation supraglottic airway devices are suitable for airway management in many laparoscopic surgeries. In this study, we evaluated and compared the ventilation parameters of the laryngeal mask airway-supreme (LM-S) and endotracheal tube (ETT) when a neuromuscular blocker (NMB) agent was not used during laparoscopic gynecological surgery. The second outcome was based on the evaluation of the surgical view because it may affect the surgical procedure.This was a randomized study that enrolled 100 patients between 18 and 65 years old with an ASA I-II classification. Patients were divided into 2 groups: Group ETT and Group LM-S. Standard anesthesia and ventilation protocols were administered to patients in each group. Ventilation parameters [airway peak pressure (Ppeak), mean airway pressure (Pmean), total volume, and oropharyngeal leak pressure] were recorded before, after, and during peritoneal insufflation and before desufflation, as well as after the removal of the airway device. Perioperative surgical view quality and the adequacy of the pneumoperitoneum were also recorded.The data of 100 patients were included in the statistical analysis. The Ppeak values in Group ETT were significantly higher in the second minute after airway device insertion. The Ppeak and Pmean values in Group ETT were significantly higher before desufflation and after removal of the airway device. No significant differences were found between the groups in terms of adequacy of the pneumoperitoneum or quality of the surgical view.The results of this study showed that gynecological laparoscopies can be performed without using a NMB. Satisfactory conditions for ventilation and surgery can be achieved while sparing the use of muscle relaxants in both groups despite the Trendelenburg position and the pneumoperitoneum of the patients, which are typical for laparoscopic gynecological surgery. The results are of clinical significance because they show that the use of a muscle relaxant is unnecessary when supraglottic airways are used for these surgical procedures.

Second generation laryngeal mask airway during laparoscopic living liver donor hepatectomy: a randomized controlled trial

The second-generation laryngeal mask airway (LMA) provides a higher sealing pressure than classical LMA and can insert the gastric drainage tube. We investigated the difference in respiratory variables according to the use of second-generation LMA and endotracheal tube (ETT) in laparoscopic living liver donor hepatectomy (LLDH). In this single-blind randomized controlled trial, intraoperative arterial carbon dioxide partial pressure at 2 h after the airway devices insertion (P_aCO_{2_}2h) was compared as a primary outcome. Participants were randomly assigned to the following groups: Group LMA (n = 45, used Protector LMA), or Group ETT (n = 43, used cuffed ETT). Intraoperative hemodynamic and respiratory variables including mean blood pressure (MBP), heart rate (HR), and peak inspiratory pressure (PIP) were compared. Postoperative sore throat, hoarseness, postoperative nausea and vomiting (PONV), and pulmonary aspiration were recorded. The P_aCO_{2_}2h were equally effective between two groups (mean difference: 0.99 mmHg, P = 0.003; 90% confidence limits: − 0.22, 2.19). The intraoperative change in MBP, HR, and PIP were differed over time between two groups (P < 0.001, P = 0.015, and P = 0.039, respectively). There were no differences of the incidence of postoperative complications at 24 h following LLDH (sore throat and hoarseness: P > 0.99, PONV: P > 0.99, and P = 0.65, respectively). No case showed pulmonary aspiration in both groups. Compared with endotracheal tube, second-generation LMA is equally efficient during LLDH. The second-generation LMA can be considered as the effective airway devices for securing airway in patients undergoing prolonged laparoscopic surgery.

Trial Registration This study was registered at the Clinical Trial Registry of Korea (https://cris.nih.go.kr. CRiS No. KCT0003711).

Baska mask versus endotracheal tube in laparoscopic cholecystectomy surgery: a prospective randomized trial

Background: Supraglottic airway devices have increasingly been used as the airway technique of choice in laparoscopic surgeries. This study compared the efficacy and safety of the Baska Mask with endotracheal tube (ETT) in patients undergoing elective laparoscopic cholecystectomy.Research design and methods: This single-center, prospective, randomized controlled trial recruited 60 patients aged 18-75 years with American Society of Anesthesiologists' classifications I to III. The time taken to achieve effective airway, number of attempts, ease of insertion, ventilation parameters, hemodynamics data, and pharyngolaryngeal complications were recorded.Results: The time taken to achieve effective airway was shorter for the Baska group (26.6 ± 4.7 vs. 47.2 ± 11.8 s; p < 0.001), although the first-time insertion success rate was ≥90% for both groups. The ETT group experienced more pharyngolaryngeal complications, including cough, trauma, spasm, dysphonia, and sore throat, during device insertion and removal and had higher systolic and diastolic blood pressures during intubation (p = 0.001). The Baska Mask achieved significantly lower peak airway pressure (p = 0.024) with stable oropharyngeal leak pressure ≥33 cmH₂O throughout the surgery.Conclusions: The Baska Mask is a suitable alternative to endotracheal intubation in selected patients undergoing laparoscopic cholecystectomy, with shorter insertion times, fewer perioperative complications, and improved ventilatory performance and hemodynamic response.Trial registration: The trial is registered at ClinicalTrials.gov (NCT03045835), 8 February 2017.

Effect of removal of AuraOnce™ laryngeal mask in awake or deep anaesthesia: a randomized controlled trial

Background

The manufacturer Ambu® recommends that the AuraOnce™ laryngeal mask be removed once the patient is fully awake. Studies have shown benefit in removal of the laryngeal mask airway while a patient is deeply anaesthetized. Current evidence is inconclusive, as to which approach is preferable and safer in adults.

Methods

one hundred and sixteen adult patients were randomly assigned to two groups of 58. For the deep arm; The AuraOnce™ laryngeal mask was removed after attaining an end tidal minimum alveolar concentration of Isoflurane of 1.15%. Occurrence of airway complication(s) (One or more of the following; Airway obstruction requiring airway manipulation; Laryngospasm; Desaturation to 90% or less on pulse oximetry) was noted until the subject was fully awake (appropriate response to command) in the post-anaesthesia care unit. For the awake arm; The AuraOnce™ laryngeal mask was removed on attaining an end tidal minimum alveolar concentration of Isoflurane of <0.5% and an appropriate response to command or obtaining appropriate response to command irrespective of end tidal concentration. Occurrence of airway complication(s) in theatre and post anaesthesia care unit was recorded. Time to theatre exit was recorded for both groups.

Results

Baseline demographic characteristics were similar between the groups. More airway complications were encountered in the Deep arm - 13 (22.4%) relative to the Awake arm -5 (8.6%), this was found to be statistically and clinically significant, P value P=0.040, odds ratio 3.0622; 95% CI, 1.0139 to 9.2483.

Conclusion

The removal of the AuraOnce™ laryngeal mask while the patient is still deeply anaesthetised is not as safe as or safer than awake removal.

Association of Mallampati scoring on airway outcomes in women undergoing general anesthesia with Supreme™ laryngeal mask airway in cesarean section

Background

Obstetric dfficult airway is a leading cause of maternal morbidity and mortality. The laryngeal mask airway (LMA) is often used as a rescue airway device after failed intubation, however, little is known about predictors of difficult LMA insertion, particularly in obstetrics. Since Mallampati scores of III/IV has been associated with difficult tracheal intubation, our present study aims to investigate if Mallampati score (MP) could predict airway outcomes for LMA use in obstetrics.

Methods

This prospective cohort study was performed at a single-center: Quanzhou Women’s and Children’s Hospital, Fujian Province, China. Five hundred and eighty-four parturients undergoing elective cesarean section under general anesthesia were recruited. The primary outcome was time to effective ventilation, and secondary outcomes included first attempt insertion success, seal pressure, ventilation and hemodynamic parameters, occurrence of clinical aspiration, and maternal and fetal outcomes.

Results

The parturients were classified into two groups based on MP of III/IV (High MP: 61) versus I/II (Low MP: 523). BMI was higher in the High MP group than in the Low MP group (mean (SD) 29.3 (7.0) vs 26.8 (3.1), p <  0.0001). There was no difference in maternal age, ASA status and gestational age. There was similar time to effective ventilation (mean (SD) High MP: 14.9 (4.5) vs Low MP: 15.7 (4.4) seconds, p = 0.2172), and first attempt success rate, seal pressure, and peak airway pressure. No clinical aspiration was noted. The incidence of blood on SLMA was higher in the High MP group than in Low MP (4 (6.6%) vs 4 (0.8%), p = 0.001). There was no difference in sore throat, voice hoarseness, maternal satisfaction and fetal outcomes.

Conclusion

High MP was not associated with reduced SLMA airway outcomes in cesarean section under general anesthesia, but may increase the risk of blood found on SLMA upon removal.

Trial registration

This study was registered at http://www.clinicaltrials.gov, identifier: NCT02026882, retrospectively registered. Date of registration: December 31, 2013.

Comparison of Supreme laryngeal mask airway versus endotracheal intubation for airway management during general anesthesia for cesarean section: a randomized controlled trial

Background

The obstetric airway is a significant cause of maternal morbidity and mortality. Endotracheal intubation is considered the standard of care but the laryngeal mask airway (LMA) has gained acceptance as a rescue airway and has been incorporated into the obstetric airway management guidelines. In this randomized controlled equivalence trial, we compared the Supreme LMA (SLMA) with endotracheal intubation (ETT) in managing the obstetric airway during cesarean section.

Methods

Parturients who underwent elective cesarean section under general anesthesia were randomized to receive either an SLMA or ETT as their airway device. Our primary outcome was first-attempt insertion success. Successful insertion was defined as adequate bilateral air entry with auscultation and the presence of end-tidal carbon dioxide on the capnogram. The first-attempt insertion success rate was compared using the Chi-Square test. Secondary outcomes included time-to-ventilation, seal pressure, ventilation/hemodynamic parameters, occurrence of clinical aspiration, fetal outcomes, and maternal side effects associated with the airway device.

Results

We recruited 920 parturients (460 SLMA, 460 ETT) who underwent elective cesarean section under general anesthesia. Patient characteristics were similar between the groups. First attempt success was similar (Odds Ratio--OR_SLMA/ETT: 1.00 (95%CI: 0.25, 4.02), p = 1.0000). SLMA was associated with reduced time to effective ventilation (Mean Difference--MD -22.96; 95%CI: − 23.71, − 22.21 s) compared to ETT group (p <  0.0001). Ventilation parameters, maternal and fetal outcomes were similar between the groups, and there was no aspiration.

Conclusions

SLMA could be an alternative airway management technique for a carefully selected low-risk obstetric population, with similar insertion success rates, reduced time to ventilation and less hemodynamic changes compared with ETT. Our findings are consistent with the airway guidelines in recommending the second-line use of LMA in the management of the obstetric airway.

Trial registration

The study was registered at http://www.clinicaltrials.gov, identifier: NCT01858467, retrospectively registered. Date of registration: May 21, 2013.

Supreme™ laryngeal mask airway use in general Anesthesia for category 2 and 3 Cesarean delivery: a prospective cohort study

Background

The Supreme™ laryngeal mask airway (SLMA) is a single-use LMA with double lumen design that allows separation of the respiratory and the alimentary tract, hence potentially reducing the gastric volume and risk of aspiration. The purpose of this prospective cohort study is to evaluate the the role of the SLMA as an airway technique for women undergoing category 2 and 3 Cesarean delivery under general anesthesia.

Methods

We recruited 584 parturients who underwent category 2 or 3 Cesarean delivery under general anesthesia, in which 193 parturients underwent category 2 and 391 parturients underwent category 3 Cesarean delivery. The primary outcome was insertion success rate at 1st attempt in SLMA insertion. The secondary outcomes included anaesthetic, obstetric outcomes and maternal side effects associated with airway device.

Results

The 1st attempt insertion success rate was 98.3%, while the overall insertion success rate was 100%. The mean (Standard deviation) time to effective ventilation was 15.6 (4.4) seconds. Orogastric tube insertion was successful at the 1st attempt in all parturients. There was no clinical evidence of aspiration or regurgitation. No episodes of hypoxemia, laryngospasm or bronchospasm were observed intra-operatively. The incidence of complications was low and with good maternal satisfaction reported.

Conclusions

The SLMA could be an alternative effective airway in category 2 and 3 parturients emergency Cesarean Delivery under general anesthesia in a carefully-selected obstetric population.

Trial registration

Clinical Trials Registration: Clinicaltrials.gov Registration NCT02026882. Registered on December 31, 2013.

ProSeal Laryngeal Mask Airway versus Cuffed Endotracheal Tube for Laparoscopic Surgical Procedures under General Anesthesia: A Random Comparative Study

Context

The Proseal LMA(PLMA), which has been designed especially for positive pressure ventilation and protection against aspiration can act as an alternative to Endotracheal Tube (ETT) as an effective airway device for patients undergoing elective Laparoscopic surgeries.

Aims

To compare the efficacy and safety of PLMA with ETT in patients undergoing Laparoscopic surgeries under general anaesthesia.

Settings and Design

A prospective, randomized study was conducted in a tertiary care teaching hospital with 60 patients of ASA grade I/II undergoing elective Laparoscopic surgery under general anaesthesia. Ethical committee clearance and written consent taken. The patients were randomly divided into two equal groups to the PLMA group (Group S) and to the ETT group (Group C) Heart rate (HR), mean blood pressure (MAP), ETCO₂ values, intraoperative complications such as regurgitation- aspiration, and Postoperative complications such as nausea or vomiting, throat soreness and oral injuries were monitored.

Results

There was no difference demographically. Insertion success rate was 100% for both the groups. The mean increase in HR was seen all throughout the duration of the surgery to 8 % above the baseline in Group C and to 3% above the baseline in Group S. On comparing the MAP in Group C, there was a increased by 2.5% to 78.300 ± 14.2615 mmHg as compared to an increase by 5% to 76.233 ± 6.2072 mmHg in Group S. EtCO2 showed a rise in both groups after pneumoperitoneum, which returned to baseline values after completion of surgery. Gastric aspirate values showed no difference in each group. Post op complications were seen mainly in Group C with statistical significance.

Conclusions

A properly positioned PLMA is a suitable and safe alternative to ETT for airway management in adequately fasted, adult patients undergoing elective Laparoscopic surgeries.

Comparison of laryngeal mask airway vs tracheal intubation: a systematic review on airway complications

To determine whether the laryngeal mask airway (LMA) has advantages over the tracheal tube (TT) in terms of incidence of cough, sore throat, laryngospasm, dysphagia, dysphonia, and blood staining. This is a systematic literature review performed at the Universtity Medical Center of Utrecht. The online databases PubMed, Embase, and the Cochrane Library were searched for relevant randomized controlled trials. Two independent reviewers selected relevant articles after title, abstract, and full text screening. Articles were assessed on risk of bias in accordance with the Cochrane risk of bias tool. Study results of the LMA and the TT were related to the method of selection of the device size and the method for cuff inflation. Of the 1718 unique articles, we included 19 studies which used the LMA Classic, the LMA Proseal, the Flexible Reinforced LMA, and the LMA Supreme compared with TT. After methodological inspection, data could not be pooled due to heterogeneity among the selected studies. Overall, no clear advantage of the LMA over the TT was found but the LMA Supreme was related to the lowest incidence of airway complications. In this review, no clear difference in incidence of postoperative airway complications could be demonstrated between LMA and TT. The LMA Supreme may reduce the incidence of airway complication in comparison to the TT but high quality randomized trials are recommended to further objectify if use of the LMA decreases the risk on postoperative airway complications.

Laryngeal tube suction II or endotracheal intubation for laparoscopic radical prostatectomy in a head down position: A randomised controlled trial

BACKGROUND

The laryngeal tube suction II (LTS II) is a supraglottic airway device (SAD) with a gastric drainage tube and enhanced seal properties as compared with other SADs. Therefore, its use has been proposed in situations with an elevated risk of aspiration.

OBJECTIVES

To compare the safety and efficacy of airway management and controlled mechanical ventilation when using either an LTS II or an endotracheal tube for laparoscopic radical prostatectomy.

DESIGN

Randomised, controlled, blinded and single-centre study.

SETTING

Academic tertiary care centre in Leipzig from April 2014 to May 2015.

PATIENTS

It was planned to include 100 patients but the study was stopped after 50 patients following an interim analysis. These 50 patients were randomised to either the LTS II group or the endotracheal tube group. All male patients aged more than 18 years for elective laparoscopic radical prostatectomy were eligible. Exclusion criteria included a BMI more than 30, American Society of Anesthesiologists class III or greater, a history of gastroesophageal reflux or other factors known to increase the risk of aspiration and a known difficult airway.

INTERVENTIONS

All patients received general anaesthesia. Airway management was with either a LTS II or an endotracheal tube, according to the randomisation.

MAIN OUTCOME MEASURES

The primary endpoint was successful insertion of the particular airway device during anaesthesia for laparoscopic radical prostatectomy.

RESULTS

In 15 of the 28 patients randomised to LTS II, the device had to be removed and an endotracheal tube inserted, mainly because of an airway leak (n = 10) or swelling of the tongue (n = 3). Ventilation was successful in all patients (n = 22) randomised to endotracheal tube. Quality of ventilation was rated better in the endotracheal tube group.

CONCLUSION

Our data suggest that LTS II should not be the preferred method of airway management in patients undergoing laparoscopic radical prostatectomy.

TRIAL REGISTRATION

DRKS00008985 (German Clinical Trials Register).

Comparison between supraglottic airway devices and endotracheal tubes in patients undergoing laparoscopic surgery: A systematic review and meta-analysis

BACKGROUND

Comparisons between the efficacies of supraglottic airway devices (SGAs) and endotracheal tubes (ETTs) in patients undergoing laparoscopic surgeries have yielded conflicting results. Therefore, in this meta-analysis, we compared the clinical performance and incidence of complications between SGAs and ETT intubation in laparoscopic surgery.

METHODS

A comprehensive search was conducted using MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, and Google Scholar to identify randomized controlled trials that compared SGAs with ETTs in laparoscopic surgery.

RESULTS

In total, 1433 patients from 17 studies were included in the final analysis. SGAs and ETTs showed no difference in insertion success rate on the first attempt (relative risk [RR] 1.01, 95% confidence interval [CI] 0.99-1.03), insertion time (standardized mean difference 1.57, 95% CI -3.74 to 0.61), and oropharyngeal leak pressure (OLP) (mean difference -2.54, 95% CI -7.59 to 2.50). The incidence of desaturation (RR 3.65, 95% CI 1.39-9.62), gastric insufflations (RR 0.90, 95% CI 0.48-1.71), regurgitation (RR 0.98, 95% CI 0.02-49.13), and aspiration (RR 0.99, 95% CI 0.01-78.4) also showed no intergroup differences. However, the incidence of laryngospasm (RR 3.12, 95% CI 1.29-7.52), cough at removal (RR 6.68, 95% CI 4.70-9.48), dysphagia (RR 1.47, 95% CI 1.12-1.95) or dysphonia (RR 4.41, 95% CI 1.25-15.55), sore throat (RR 1.60, 95% CI 1.33-1.93), and hoarseness (RR 1.53, 95% CI 1.29-1.81) was higher in the ETT group than in the SGA group.

CONCLUSIONS

The incidence of laryngospasm, cough at removal, dysphagia or dysphonia, sore throat, and hoarseness were higher in the ETT group than in the SGA group. However, the groups showed no differences in the rate of insertion success on the first attempt, insertion time, OLP, and other complications. Therefore, SGAs might be clinically more useful as effective airways in laparoscopic surgery.

Anaesthesia for minimally invasive surgery

Minimally invasive surgery (MIS) is rising in popularity. It offers well-known benefits to the patient. However, restricted access to the surgical site and gas insufflation into the body cavities may result in severe complications. From the anaesthetic point of view MIS poses unique challenges associated with creation of pneumoperitoneum, carbon dioxide absorption, specific positioning and monitoring a patient to whom the anaesthetist has often restricted access, in a poorly lit environment. Moreover, with refinement of surgical procedures and growing experience the anaesthetist is presented with patients from high-risk groups (obese, elderly, with advanced cardiac and respiratory disease) who once were deemed unsuitable for the laparoscopic technique. Anaesthetic management is aimed at getting the patient safely through the procedure, minimizing the specific risks arising from laparoscopy and the patient's coexisting medical problems, ensuring quick recovery and a relatively pain-free postoperative course with early return to normal function.

Effect of pneumoperitoneum and Trendelenberg position on oropharyngeal sealing pressure of I-gel™ and ProSeal LMA™ in laparoscopic gynecological surgery: A randomized controlled trial

Background:

A sustained and effective oropharyngeal sealing with supraglottic airway (SGA) is required to maintain the ventilation during laparoscopic gynecological surgery in the Trendelenburg position. This study was conducted with I-gel™ and ProSeal LMA™, two prototype SGA devices with a gastric access.

Materials and Methods:

We enrolled 60 American Society of Anesthesiologists physical status I and II patients and randomized to either I-gel or ProSeal LMA (PLMA) group. After induction of anesthesia using a standardized protocol, one of the SGA devices was inserted. The primary objective of this study was to compare the oropharyngeal leak (sealing) pressure of I-gel™ and ProSeal LMA™ after pneumoperitoneum and Trendelenberg position. The secondary objectives were to compare ease of insertion, cuff position as assessed by the fiberoptic view of the glottis, adequacy of ventilation and incidence of complication.

Results:

The baseline (before pneumoperitoneum) oropharyngeal leak pressure of I-gel was less than the PLMA (mean (standard deviation [SD]) 24 (4) vs. 29 (4) cmH₂O, respectively; P < 0.001). After pneumoperitoneum, the leak airway pressure in I-gel group was significantly less than that of PLMA group (mean [SD] 27 (3) vs. 34.0 (4) cmH₂O, respectively; P < 0.001). Peak airway pressure was increased after pneumoperitoneum compared to baseline in both the groups. However, end-tidal carbon dioxide was maintained within normal limits. The insertion parameters, fiberoptic view of the glottis, fiberoptic view of the drain tube, and complications were comparable between the groups.

Conclusion:

Both I-gel and PLMA are effective for ventilation in gynecological laparoscopic surgeries. However, PLMA provides better sealing as compared to I-gel.

Comparison of the proseal, supreme, and i-gel SAD in gynecological laparoscopic surgeries

We compared proseal, supreme, and i-gel supraglottic airway devices in terms of oropharyngeal leak pressures and airway morbidities in gynecological laparoscopic surgeries. One hundred and five patients undergoing elective surgery were subjected to general anesthesia after which they were randomly distributed into three groups. Although the oropharyngeal leak pressure was lower in the i-gel group initially (mean ± standard deviation; 23.9 ± 2.4, 24.9 ± 2.9, and 20.9 ± 3.5, resp.), it was higher than the proseal group and supreme group at 30 min of surgery after the trendelenburg position (25.0 ± 2.3, 25.0 ± 1.9, and 28.3 ± 2.3, resp.) and at the 60 min of surgery (24.2 ± 2.1, 24.8 ± 2.2, and 29.5 ± 1.1, resp.). The time to apply the supraglottic airway devices was shorter in the i-gel group (12.2 (1.2), 12.9 (1.0), and 6.7 (1.2), resp., P = 0.001). There was no difference between the groups in terms of their fiber optic imaging levels. pH was measured at the anterior and posterior surfaces of the pharyngeal region after the supraglottic airway devices were removed; the lowest pH values were 5 in all groups. We concluded that initial oropharyngeal leak pressures obtained by i-gel were lower than proseal and supreme, but increased oropharyngeal leak pressures over time, ease of placement, and lower airway morbidity are favorable for i-gel.

Use of extraglottic airways in patients undergoing ambulatory laparoscopic surgery without the need for tracheal intubation

Background:

Second generation extraglottic airway devices with gastric access and separate breathing channels have ushered in a new era where their use is increasingly prevalent in surgical patients who would have been traditionally intubated for general anesthesia. New innovations like the i-gel, which is constructed of a thermoplastic elastomer, provide an airtight seal around patient's perilaryngeal anatomy without the inflatable cuff mechanism found in the laryngeal mask airway supreme (LMAS).

Methods:

We conducted a randomized controlled trial comparing the LMAS with the i-gel in 70 anesthetized paralyzed patients undergoing laparoscopic female sterilization. Our primary outcome measure was the oropharyngeal leak pressure (OLP). We studied secondary outcomes of successful first attempt insertion rates, time and ease of the airway and gastric tube insertion, leak fractions and pharyngeal morbidity.

Results:

We found no difference in the OLP between LMAS and i-gel, 25.9 (4.2) versus 24.4 (4.3) s, P=0.153. Both devices had similar first attempt insertion rates (LMAS 94% vs. i-gel 91%) with similar ease and comparable times to achieve an effective airway, LMAS 14.7 (2.7) versus i-gel 16.5 (9.6) s, P=0.306, although gastric tube insertion was easier and faster for the LMAS, 7.9 (1.9) versus i-gel 14.8 (7.7) s, P<0.005. Intraoperatively, there was a significantly greater leak fraction with the i-gel of 0.06 (0.03) versus 0.04 (0.02) with the LMAS, P=0.013. Three patients (8.6%) with LMAS had mild sore throat; one patient (2.9%) had mucosal injury. No complications were documented in the i-gel group.

Conclusions:

Both these extraglottic airway devices offer similar OLPs, high insertion success rates at the first attempt with similar ease and insertion times (albeit longer gastric tube insertion with i-gel). Both provided effective ventilation despite a higher leak fraction with i-gel that was clinically inconsequential.

Prospective, randomized clinical trial of laryngeal mask airway Supreme(®) used in patients undergoing general anesthesia

BACKGROUND AND OBJECTIVES

Supraglottic airway devices are increasingly used as an option to tracheal intubation for elective procedures of varying complexity. The aim of this study was to prospectively evaluate the clinical use of the laryngeal mask airway Supreme(®) (LMAS) in patients undergoing elective breast surgery and compare it with endotracheal tube (ETT).

METHODS

Sixty patients undergoing breast procedures under general anesthesia were randomly divided into two groups according to the device used (LMAS or ETT). Time of insertion, number of insertion attempts, hemodynamic response to insertion, presence of blood on the device used; and incidence of sore throat, dysphagia, nausea and vomiting were assessed postoperatively.

RESULTS

There was no difference between groups regarding time of insertion, number of attempts for successful insertion, and presence of blood on the device. Heart rate and blood pressure after insertion were higher in ETT group. Incidence of sore throat and dysphagia was also higher in ETT group after two hours in the postoperative period. There was no difference regarding incidence and severity of complications evaluated after six hours postoperatively.

CONCLUSIONS

The use of the LMAS technique to access airway during general anesthesia for elective breast surgery is as safe and effective as tracheal intubation, with the advantage of promoting smaller hemodynamic response during its management and lower incidence of sore throat and dysphagia in the first hours after surgery.

Supraglottic airway devices versus tracheal intubation for airway management during general anaesthesia in obese patients

BACKGROUND

The number of obese patients requiring general anaesthesia is likely to increase in coming years, and obese patients pose considerable challenges to the anaesthetic team. Tracheal intubation may be more difficult and risk of aspiration of gastric contents into the lungs is increased in obese patients. Supraglottic airway devices (SADs) offer an alternative airway to traditional tracheal intubation with potential benefits, including ease of fit and less airway disturbance. Although SADs are now widely used, clinical concerns remain that their use for airway management in obese patients may increase the risk of serious complications.

OBJECTIVES

We wished to examine whether supraglottic airway devices can be used as a safe and effective alternative to tracheal intubation in securing the airway during general anaesthesia in obese patients (with a body mass index (BMI) > 30 kg/m(2)).

SEARCH METHODS

We searched for eligible trials in the following databases: Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 8, 2012), MEDLINE via Ovid (from 1985 to 9 September 2012) and EMBASE via Ovid (from 1985 to 9 September 2012). The Cochrane highly sensitive filter for randomized controlled trials was applied in MEDLINE and EMBASE. We also searched trial registers such as www.clinicaltrials.gov and the Current Controlled Clinical Trials Website (http://www.controlled-trials.com/) for ongoing trials. The start date of these searches was limited to 1985, shortly before the first SAD was introduced, in 1988. We undertook forward and backward citation tracing for key review articles and eligible articles identified through the electronic resources.

SELECTION CRITERIA

We considered all randomized controlled trials of participants aged 16 years and older with a BMI > 30 kg/m(2) undergoing general anaesthesia. We compared the use of any model of SAD with the use of tracheal tubes (TTs) of any design.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by The Cochrane Collaboration. Two review authors independently assessed trial quality and extracted data, including information on adverse events. We contacted study authors for additional information. If sufficient data were available, results were presented as pooled risk ratios (RRs) with 95% confidence intervals (CIs) based on random-effects models (inverse variance method). We employed the Chi(2) test and calculated the I(2) statistic to investigate study heterogeneity.

MAIN RESULTS

We identified two eligible studies, both comparing the use of one model of SAD, the ProSeal laryngeal mask airway (PLMA) with a TT, with a total study population of 232. One study population underwent laparoscopic surgery. The included studies were generally of high quality, but there was an unavoidable high risk of bias in the main airway variables, such as change of device or laryngospasm, as the intubator could not be blinded. Many outcomes included data from one study only.A total of 5/118 (4.2%) participants randomly assigned to PLMA across both studies were changed to TT insertion because of failed or unsatisfactory placement of the device. Postoperative episodes of hypoxaemia (oxygen saturation < 92% whilst breathing air) were less common in the PLMA groups (RR 0.27, 95% CI 0.10 to 0.72). We found a significant postoperative difference in mean oxygen saturation, with saturation 2.54% higher in the PLMA group (95% CI 1.09% to 4.00%). This analysis showed high levels of heterogeneity between results (I(2) = 71%). The leak fraction was significantly higher in the PLMA group, with the largest difference seen during abdominal insufflation－a 6.4% increase in the PLMA group (95% CI 3.07% to 9.73%).No cases of pulmonary aspiration of gastric contents, mortality or serious respiratory complications were reported in either study. We are therefore unable to present effect estimates for these outcomes.In all, 2/118 participants with a PLMA suffered laryngospam or bronchospasm compared with 4/114 participants with a TT. The pooled estimate shows a non-significant reduction in laryngospasm in the PLMA group (RR 0.48, 95% CI 0.09 to 2.59).Postoperative coughing was less common in the PLMA group (RR 0.10, 95% CI 0.03 to 0.31), and there was no significant difference in the risk of sore throat or dysphonia (RR 0.25, 95% CI 0.03 to 2.13). On average, PLMA placement took 5.9 seconds longer than TT placement (95% CI 3 seconds to 8.8 seconds). There was no significant difference in the proportion of successful first placements of a device, with 33/35 (94.2%) first-time successes in the PLMA group and 32/35 (91.4%) in the TT group.

AUTHORS' CONCLUSIONS

We have inadequate information to draw conclusions about safety, and we can only comment on one design of SAD (the PLMA) in obese patients. We conclude that during routine and laparoscopic surgery, PLMAs may take a few seconds longer to insert, but this is unlikely to be a matter of clinical importance. A failure rate of 3% to 5% can be anticipated in obese patients. However, once fitted, PLMAs provide at least as good oxygenation, with the caveat that the leak fraction may increase, although in the included studies, this did not affect ventilation. We found significant improvement in oxygenation during and after surgery, indicating better pulmonary performance of the PLMA, and reduced postoperative coughing, suggesting better recovery for patients.

Comparison of ProSeal LMA with Supreme LMA in paediatric patients

BACKGROUND AND OBJECTIVE

Supreme laryngeal mask airway (S-LMA) has been improved in recent years, but comparative studies with a sizeable number of paediatric patients are limited in number. In this study, oropharyngeal leak pressures (OLPs) were compared between S-LMA and ProSeal laryngeal mask airway (P-LMA) in paediatric patients.

METHODS

After obtaining approval from the ethics committee and written informed consent from the relatives of the patients, 60 patients, from 9 months to 5 years of age and 10-20 kg in weight, who were recommended for elective surgery were included in this prospective and randomised study. The patients were assigned to the S-LMA and P-LMA groups. OLP, insertion times, success rates, ease of airway device placement, fibre optical assessment, success rates and insertion times of an orogastric tube (OGT) were compared.

RESULTS

P-LMA was placed successfully in all the patients. One patient was intubated in the S-LMA group. The outcomes of a total of 59 patients were analysed. The insertion times of the airway devices were shorter in the S-LMA group than in the P-LMA group (S-LMA; 12.2 ± 2.9, P-LMA; 15.4 ± 3.7 s) (P = 0.001). The first insertion attempts of airway device placement were similar. The OLPs were similar (P-LMA; 17.2 ± 2.3, S-LMA; 16.4 ± 1.7 cm H2 O). The fibre-optically determined anatomic position was better in the P-LMA group (P = 0.02). The insertion time of the OGT was shorter with S-LMA than with P-LMA (P = 0.01).

CONCLUSION

Our findings suggest that S-LMA has OLPs similar to those of P-LMA in paediatric patients and that S-LMA provides successful positive pressure ventilation.

Is muscle relaxant necessary in patients undergoing laparoscopic gynecological surgery with a ProSeal LMA™?

STUDY OBJECTIVE

To test the hypothesis that muscle relaxant is not necessary in patients who are undergoing laparoscopic gynecological surgery with a ProSeal Laryngeal Mask Airway (ProSeal LMA™).

DESIGN

Prospective, randomized study.

SETTING

Operating room of Sichuan Provincial Hospital for Women and Children.

PATIENTS

120 adult, ASA physical status 1 and 2 women, aged 18 to 55 years.

INTERVENTIONS AND MEASUREMENTS

Patients were randomly assigned to two groups (n=60) to receive a muscle relaxant (Group MR) or not (Group NMR). General anesthesia was used in patients of both groups for airway management with the ProSeal LMA. Peak airway inflation pressures, airway sealing pressure, minimum flow rate, and recovery time were assessed. Surgical conditions were assessed by the operating gynecologist. The frequency of sore throats was recorded.

MAIN RESULTS

ProSeal LMA insertion was 100% successful. Patients' lungs were ventilated with a maximum sealing pressure of 32 ± 5.1 cm H(2)O (Group MR) or 31 ± 4.9 cm H(2)O (Group NMR) (P = 0.341). The seal quality in both groups permitted the use of low flows: 485 ± 291 mL/min in Group MR and 539 ± 344 mL/min in Group NMR (P = 0.2). Surgical conditions were comparable between the two groups. There was no difference in the frequency of sore throats (20% vs 21.7%; P = 0.28). In Group NMR, there was a statistically significant reduction in recovery time versus Group MR (4.5 ± 2.6 min vs 10.3 ± 4.2 min; P < 0.01).

CONCLUSION

Muscle relaxant is not necessary in general anesthesia with a ProSeal LMA.

The LMA Supreme™ in 700 parturients undergoing Cesarean delivery: an observational study

BACKGROUND

The LMA Supreme™ (SLMA) is a single-use supraglottic device that provides a good seal for positive pressure ventilation. It has a double aperture design that facilitates the introduction of an orogastric tube to aspirate gastric contents. This observational study evaluated the role of the SLMA in parturients undergoing Cesarean delivery under general anesthesia.

METHODS

Non-obese parturients with at least four hours of fasting and antacid prophylaxis scheduled for uncomplicated Cesarean delivery were recruited from June 2009 through May 2010 at the Quanzhou Women's and Children's Hospital, China. We recorded the number of SLMA insertion attempts, the time to effective ventilation, the incidence of aspiration, and other anesthetic and obstetric outcomes. Postoperatively, we noted the presence of blood on the SLMA, postoperative sore throat, and patient satisfaction. Analysis included comparison of results between parturients having elective and urgent Cesarean delivery.

RESULTS

We recruited 700 parturients (576 elective, 124 urgent). Mean (standard deviation) body mass index was 25.6 (2.5) kg·m(-2). All SLMA insertions were successful, with 686 (98%) inserted on first attempt and a time to effective airway of 19.5 (3.9) sec. We maintained ventilation and oxygenation in all parturients with a good seal and there was no evidence of aspiration. Eighteen parturients (2.6%) had blood on the SLMA upon removal, 24 (3.4%) had sore throat, and patient satisfaction was 85 (7)%. These results were similar in elective and urgent cases.

CONCLUSIONS

In a carefully selected group of parturients, the SLMA is a useful alternative to tracheal intubation for Cesarean delivery, providing effective ventilation and a low incidence of side effects or complications.

ProSeal laryngeal mask airway: An alternative to endotracheal intubation in paediatric patients for short duration surgical procedures

The laryngeal mask airway (LMA) is a supraglottic airway management device. The LMA is preferred for airway management in paediatric patients for short duration surgical procedures. The recently introduced ProSeal (PLMA), a modification of Classic LMA, has a gastric drainage tube placed lateral to main airway tube which allows the regurgitated gastric contents to bypass the glottis and prevents the pulmonary aspiration. This study was done to compare the efficacy of ProSeal LMA with an endotracheal tube in paediatric patients with respect to number of attempts for placement of devices, haemodynamic responses and perioperative respiratory complications. Sixty children, ASA I and II, weighing 10-20 kg between 2 and 8 years of age group of either sex undergoing elective ophthalmological and lower abdominal surgeries of 30-60 min duration, randomly divided into two groups of 30 patients each were studied. The number of attempts for endotracheal intubation was less than the placement of PLMA. Haemodynamic responses were significantly higher (P<0.05) after endotracheal intubation as compared to the placement of PLMA. There were no significant differences in mean SpO(2) (%) and EtCO(2) levels recorded at different time intervals between the two groups. The incidence of post-operative respiratory complications cough and bronchospasm was higher after extubation than after removal of PLMA. The incidence of soft tissue trauma was noted to be higher for PLMA after its removal. There were no incidences of aspiration and hoarseness/sore throat in either group. It is concluded that ProSeal LMA can be safely considered as a suitable and effective alternative to endotracheal intubation in paediatric patients for short duration surgical procedures.

Laryngeal mask airways have a lower risk of airway complications compared with endotracheal intubation: a systematic review

PURPOSE

The purpose of the present study was to determine whether, in patients undergoing general anesthesia, those provided with a laryngeal mask airway (LMA) have a lower risk of airway-related complications than those undergoing endotracheal intubation.

MATERIALS AND METHODS

A systematic review of randomized prospective controlled trials was done to compare the risk of airway complications with an LMA versus an endotracheal tube (ETT) in patients receiving general anesthesia. Two independent reviewers identified 29 randomized prospective controlled trials that met the predetermined inclusion and exclusion criteria. The data for each individual outcome measure were combined to analyze the relative risk ratios (RRs). The Cochrane RevMan software was used for statistical analysis.

RESULTS

When an ETT was used to protect the airway, a statistically significant greater incidence of hoarse voice (RR 2.59, 95% confidence interval [CI] 1.55 to 4.34), a greater incidence of laryngospasm during emergence (RR 3.16, 95% CI 1.38 to 7.21), a greater incidence of coughing (RR 7.12, 95% CI 4.28 to 11.84), and a greater incidence of sore throat (RR 1.67, 95% CI 1.33 to 2.11) was found compared with when an LMA was used to protect the airway. The differences in the risk of regurgitation (RR 0.84, 95% CI 0.27 to 2.59), vomiting (RR 1.56, 95% CI 0.74 to 3.26), nausea (RR 1.59, 95% CI 0.91 to 2.78), and the success of insertion on the first attempt (RR 1.08, 95% CI 0.99 to 1.18) were not statistically significant between the 2 groups.

CONCLUSIONS

For the patients receiving general anesthesia, the use of the LMA resulted in a statistically and clinically significant lower incidence of laryngospasm during emergence, postoperative hoarse voice, and coughing than when using an ETT. The risk of aspiration could not be determined because only 1 study reported a single case of aspiration, which was in the group using the ETT.

Disposable versus reusable laryngeal tube suction for ventilation in patients undergoing laparoscopic cholecystectomy

BACKGROUND AND OBJECTIVE

The laryngeal tube suction II (LTS-II) is a recent version of reusable supraglottic airway devices allowing gastric drainage. In this prospective, randomized study we compared insertion and ventilation of disposable LTS-II (LTS-D) with reusable type (LTS-II) for airway management under conditions with elevated intra abdominal pressure induced by capnoperitoneum.

METHODS

60 ASA I and II patients undergoing elective laparoscopic cholecystectomy were randomized to receive either a LTS-D (n=30) or LTS-II (n=30) for airway management. After induction of general anaesthesia the devices were inserted, their correct placement was verified and airway leak pressure was measured. Ease of insertion, quality of airway seal, fiberoptic view, risk of gastric insufflation, insertion of nasogastric tube and postoperative pharyngeal morbidity were examined.

RESULTS

First time and second time success rates were comparable for both groups (86% vs. 93% and 96% vs. 96% in LTS-D and LTS-II groups, respectively). One patient in each group could not be intubated after three attempts. After gas insufflation, ventilation of one patient in LTS-D and 2 patients in LTS-II groups was faulty and the patients were intubated with endotracheal tube. Time until delivery of first tidal volume for LTS-D and LTS-II was 20.8 +/- 11.6 s, and 18.2 +/- 4.8 seconds respectively (p = 0.27), fixation and manipulation time was 73.3 +/- 18.5 and 65.5 +/- 16.2 seconds, respectively (p = 0.096). Nasogastric tube insertion was successful in all patients. There were no significant differences in postoperative complaints.

CONCLUSIONS

Both devices provide a secure airway under conditions of elevated intra abdominal pressure.

Comparison of the Single-use LMA Supreme with the Reusable ProSeal LMA for Anaesthesia in Gynaecological Laparoscopic Surgery

The Laryngeal Mask Airway Supreme (LMAS) is a new, single-use laryngeal mask airway with gastric access. We conducted a randomised controlled study comparing the LMAS with the reusable ProSeal Laryngeal Mask Airway (PLMA) in 70 patients undergoing general anaesthesia with paralysis for gynaecological laparoscopic surgery. Our primary outcome measure was the oropharynegal leak pressure. We also compared the two devices for ease of insertion, adequacy of ventilation and incidence of complications. Both devices had similar rates of successful insertion at the first attempt (LMAS 94% vs PLMA 91%). There was no difference in the time to establish an effective airway (LMAS 25±22 vs PLMA 24±9 seconds), although gastric tube insertion was faster for the LMAS (5±1 vs 7±3 seconds, P <0.001). The mean oropharyngeal leak pressure in the LMAS was significantly lower than in the PLMA (27.9±4.7 vs 31.7±6.3 cmH2O, P=0.007). This was consistent with a lower maximum tidal volume achieved with the LMAS (481±76 vs 515±63 ml, P=0.044). We found that after 60 minutes the cuff pressure was significantly higher in the PLMA (110±21 vs 57±8 cmH2O, P <0.001). There was no difference in the ability to provide adequate ventilation and oxygenation during anaesthesia. Complication rates were similar. We conclude that the oropharyngeal leak pressure and the maximum achievable tidal volume are lower with the LMAS than with the PLMA.

Larynxmaske

Introduction of the laryngeal mask airway (LMA) has been a revolutionary development in airway management over the last decades. It was first used clinically in 1981 by A. Brain and has been widely used in Germany since 1990. Originally intended as a substitute for conventional mask respiration for short periods of general anaesthesia, the laryngeal mask is in the meantime used in many areas as an alternative to elective endotracheal intubation as well as an option for controlling difficult airways. This contribution provides an overview of the basics as well as practical aspects of LMA use, and discusses the possibilities and limitations of the laryngeal mask in daily practice.