Advantages of ProSeal and SLIPA airways over tracheal tubes for gynecological laparoscopies

Comparison of the Laryngeal Mask Airway ProSeal and the Streamlined Liner of the Pharynx Airway During General Anesthesia: A Systematic Review and Meta-analysis

PURPOSE

The purpose of this article is to compare the safety of the laryngeal mask airway ProSeal (PLMA) and the streamlined liner of the pharynx airway (SLIPA) during general anesthesia.

DESIGN

This study is a systematic review and meta-analysis.

METHODS

Two authors performed searches of Embase, Web of Science, and PubMed to identify clinical trials that compared PLMA and SLIPA in patients receiving general anesthesia. Relative risk (RR) with corresponding 95% confidence intervals (CI) were used to pool the dichotomous data. The mean difference (MD) and the associated 95% CI were applied to pool continuous data. RevMan 5.0 software was used for data analysis.

FINDINGS

A total of 15 studies with 1263 patients were included. There was no significant difference between PLMA and SLIPA in the rate of insertion success on the first attempt (RR = 1.02, 95% CI [0.95, 1.09], P = .59), airway sealing pressure (MD = 0.75, 95% CI [-0.09, 1.58], P = .08) and the incidence of a sore throat (RR = 0.85, 95% CI [0.7, 1.04], P = .12). The insertion time of PLMA was shorter than SLIPA (MD = 5.24, 95% CI [0.51, 9.98], P = .03), and the incidence of bloodstaining on the device was lower (RR = 0.72, 95% CI [0.55, 0.94], P = .02).

CONCLUSIONS

Both devices have a high rate of insertion success on the first attempt and airway sealing pressure. But PLMA has a shorter insertion time and less incidence of blood staining, which is more advantageous than SLIPA.

Prewarming non-inflatable cuff laryngeal mask for mechanical ventilation: A systematic review and meta-analysis with trial sequential analysis

BACKGROUND

Non-inflatable cuff laryngeal masks are generally composed of thermoplastic material. The thermoplastic nature of the non-inflatable cuff will become soft and match the laryngeal anatomy better as it reaches body temperature after intubation. This meta-analysis aims to evaluate the clinical validity of prewarming non-inflatable cuff laryngeal mask before insertion.

METHODS

We searched PubMed, Cochrane Library, Embase, Web of Science, Ovid Medline, CNKI, Wan Fang Database and VIP Database to find randomized controlled trials (RCTs) researching the clinical validity of prewarming non-inflatable cuff laryngeal mask. The retrieval time is up to June 2022. Articles published in the English and Chinese languages were considered. Quality assessment was conducted with the Cochrane Collaboration's tool and GRADE (Grading of Recommendations Assessment, Development and Evaluation) method. Subgroup analyses and trial sequential analysis (TSA) were performed to control the risk of random errors. Publication bias was assessed by funnel plots and Egger's regression test. The outcomes included sealing pressure immediately after successful ventilation, the first-attempt intubation success rate and the incidence of postoperative pharyngeal pain.

RESULTS

Eight RCTs evaluating 683 patients were identified. Pooled results showed that compared to the control group, prewarming non-inflatable cuff laryngeal mask provided a higher sealing pressure immediately after successful ventilation (mean difference: 1.73 cm H2O; 95% confidence interval [CI]: 0.95-2.52; P < .0001; I2 = 16; high quality), higher first-attempt intubation success rate (risk ratio [RR]: 1.05; 95% CI: 1.01-1.09; P = .01; I2 = 26%; high quality, number needed to treat [NNT] = 22 [95% CI 12.5-100]) and lower incidence of postoperative pharyngeal pain (RR: 0.59, 95% CI: 0.46-0.75; P < .0001; I2 = 0; high quality, NNT = 6 [95% CI 4.17-9.09]). The results were confirmed by TSA.

CONCLUSION

Prewarming non-inflatable cuff laryngeal mask could provide better mechanical ventilation efficiency with higher sealing pressure, a higher first-attempt intubation success rate and a lower incidence of postoperative pharyngeal pain.

TRIAL REGISTRATION NUMBER

PROSPERO CRD42021245350.

Traditional Chinese Medicine Compounds Containing Lonicera japonica, Chrysanthemum morifolium, and Siraitia grosvenorii Inhibits the Growth of Streptococcus mutans

Postoperative sore throat (POST) is one of the common complications after endotracheal intubation under general anesthesia. This work attempted to design and screen out the traditional Chinese medicine (TCM) compounds containing Lonicera japonica Thunb., Chrysanthemum morifolium Ramat., and Siraitia grosvenorii (Swingle) C. Jeffrey ex A. M. Lu et Z. Y. Zhang, and further explored its antibacterial effect on POST. The antibacterial activities of Lonicera japonica, Chrysanthemum morifolium, and Siraitia grosvenorii on Streptococcus mutans (S. mutans) UA159 was measured. Lonicera japonica (40 mg/mL), Chrysanthemum morifolium (10 mg/mL), and Siraitia grosvenorii (10 mg/mL) effectively inhibited the growth of S. mutans. Then, 5 different TCM compounds were designed using the U5 (5³) uniform design experimentation method. TCM compound C3 (50 mg/mL Lonicera japonica, 10 mg/mL Chrysanthemum morifolium, and 15 mg/mL Siraitia grosvenorii) significantly promoted the inhibition zone and inhibited the biofilm formation of S. mutans. In addition, TCM compound C3 exerted great antibacterial effects on S. mutans and had the least effect on cell viability of primary human pharyngeal epithelial cells. In conclusion, this work demonstrated that TCM compound containing Lonicera japonica, Chrysanthemum morifolium, and Siraitia grosvenorii inhibited the growth of S. mutans. Thus, this study provides a theoretical basis for screening out the optimal compatibility of effective components in TCM mouthwash for relieving POST.

Comparison of the third-generation streamlined liner of the pharynx airway (SLIPA-3G) with the laryngeal mask airway supreme for laparoscopic cholecystectomy: a randomized prospective study

Background

The third-generation streamlined liner of the pharynx airway (SLIPA-3G) is a new-generation supraglottic airway device (SAD) that is non-cuffed and disposable, with a sealing pressure that varies dynamically with the airway pressure. This study compared the SLIPA-3G with the laryngeal mask airway supreme (LMAS) in patients undergoing laparoscopic cholecystectomy.

Methods

Two hundred and twenty patients scheduled for laparoscopic cholecystectomy were randomly allocated to either the SLIPA-3G group or the LMAS group. Data were collected on the patients’ hemodynamic parameters at different time points, ease of insertion, fiberoptic view, oropharyngeal leak pressure (OLP) at different time points and SAD-related complications.

Results

The mean OLP immediately after device placement in the LMAS group was significantly higher than that of the SLIPA-3G group (31.34 ± 6.99 cmH₂O vs.28.94 ± 6.01 cmH₂O, P = 0.008, 95% CI 0.62–4.17). The OLPs of the two groups were not significantly different after the induction of a pneumoperitoneum until the end of surgery. The OLP increased gradually through the course of the operation in the SLIPA-3G group (P value = 0.035) but not in the LMAS group (P value = 0.945). There was no significant difference between the two groups in hemodynamic parameters, insertion time and success rate, fiberoptic view and complication rate.

Conclusions

The SLIPA-3G and LMAS were associated with comparable OLPs, hemodynamic parameters, ease of insertion, fiberoptic views and complication rates when used during laparoscopic cholecystectomy. The SLIPA-3G can be used as an effective alternative to the LMAS in patients undergoing laparoscopic surgeries.

AutoFlow® versus volume-controlled ventilation for laparoscopic gynecological surgery using LMA® ProSeal™: a randomized controlled trial

Background

During laparoscopic gynecological surgery, increased peak airway pressure (PAWP) can cause airway leak upon ventilation with the LMA® ProSeal™. We hypothesized that compared with the use of volume-controlled ventilation (VCV), the use of the AutoFlow® mode would decrease PAWP and airway leak during laparoscopic gynecological surgery with LMA ProSeal.

Methods

This single-center, randomized, controlled trial allocated 80 adult women undergoing elective laparoscopic gynecological surgery to one of two groups, namely, the AutoFlow group or the VCV group. Ventilation settings for both groups were 8 ml/kg of tidal volume and 5 cmH₂O of positive end-expiratory pressure, and respiratory rate was adjusted to maintain end-tidal carbon dioxide at 35–40 mmHg. Airway leak, PAWP, and other ventilatory parameters and vital signs were recorded at four timepoints (1, 1 min after insertion of the gastric tube; 2, 2 min after intravenous administration of rocuronium 0.6–0.8 mg/kg; 3, 1 min after initiation of pneumoperitoneum; and 4, 1 min after changing to the Trendelenburg position). The primary outcome was PAWP during pneumoperitoneum and in the Trendelenburg position, whereas the secondary outcomes included PAWP at other timepoints and airway leak development. We used the Mann–Whitney U test for PAWP and Fisher’s exact test for comparing airway leak among the groups.

Results

Data from 40 patients in the AutoFlow group and 39 in the VCV group were used for analysis. PAWP at pneumoperitoneum pressure and in the Trendelenburg position was significantly lower in the AutoFlow group than in the VCV group [median (interquartile range), 16 (15–18) cmH₂O vs. 18 (17–19) cmH₂O; P < 0.001]. Similarly, patients in the AutoFlow group showed lower PAWP at the other three timepoints measured. Airway leak occurred in four patients in the AutoFlow group and in two patients in the VCV group; however, this incidence was not significantly different (P = 0.68).

Conclusions

Even though AutoFlow ventilation decreased PAWP, it did not reduce the incidence of airway leak compared with VCV during laparoscopic gynecological surgery with the LMA ProSeal.

Trial registration

UMIN Clinical Trials Registry, identifier UMIN000023173.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-021-01406-6.

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.

Comparison of LM-Supreme™ and endotracheal tube in patients undergoing gynecological laparoscopic surgery

While laryngeal mask is widely used for laparoscopic interventions in some countries, concerns exist regarding pulmonary aspiration and inadequate ventilation. We compared the LM-Supreme™ (LM-S) with the endotracheal tube (ETT) for laparoscopic gynecological interventions in terms of ventilation parameters and gastric distention. This prospective randomized and double-blind study. The patients were divided into two groups: ETT (n = 50) and LM-S group (n = 50). All patients in the LM-S and ETT groups recieved total intravenous general anaesthesia and standard ventilation protocols. Ventilation parameters (airway peak pressure, mean airway pressure, end-tidal carbon dioxide, total volume, oropharyngeal leak pressure) and perioperative laryngopharyngeal morbidity were recorded before peritoneal insufflation, during and after the peroperative period. The mean airway pressure values in the ETT group 2 min after airway device insertion were significantly higher. The gastric distension after the laparoscope entered the abdomen in the LM-S group was found to be significantly lower. In the first hour postoperative sore throat, disphonia and dysphagia were statistically significantly higher in the ETT group. In our study we concluded that LM-S provides reliable endotracheal intubation in ASA I & II patients undergoing laparoscopic gynecological surgery under positive pressure ventilation.ClinicalTrials.gov ID NCT02127632.

Evaluation of performance of Streamlined Liner of the Pharynx Airway™, Laryngeal Mask Airway-ProSeal and endotracheal tube in prone position: A prospective, randomised study

Background and Aims:

Airway used in prone position should be efficacious and safe. The Streamlined Liner of the Pharynx Airway (SLIPA™) and Laryngeal Mask Airway-ProSeal (PLMA) provide better airway seal and protection against aspiration. We planned to evaluate the performance of SLIPA™, PLMA and endotracheal tube (ETT) in prone position.

Methods:

114 adult patients undergoing elective surgery in prone position under general anaesthesia were randomised into Group-T (ETT), Group-S (SLIPA™) and Group-P (PLMA). Airways were inserted in supine position and patients turned prone subsequently. Airway characteristics, ventilatory parameters and complications were noted. One-way analysis of variance, Mann–Whitney U-test and Chi-square or Fisher's exact test were used.

Results:

Tidal volumes, peak airway pressure and compliance were comparable at all times. Leak pressure was significantly higher (P < 0.001) in Group-T (mean leak pressure = 40 cmH₂O) when compared to Group-S and Group-P at all the times of recording, and there was no significant difference between Group-S and Group-P. The number of patients requiring airway/neck manipulation in prone position was significantly higher (P < 0.001) in Group-S (19 [55.9%]) when the three groups were compared (none in Group-T) and in comparison with Group-P (5 [14.7%], P < 0.001). On airway removal, the incidence of complications and airway reaction was significantly higher in Group-T. Group-S had a significantly higher incidence of dysphagia at 2 h postoperatively.

Conclusion:

ETT was most efficacious. SLIPA™ and PLMA were efficacious, safe and less stimulating to the airway during removal. More patients required SLIPA™ airway/neck manipulation.

Insertion methods comparison for The Streamlined Liner of the Pharynx Airway in children by novice

BACKGROUND

The Streamlined Liner of the Pharynx Airway (SLIPA™) is a popular supraglottic airway device used for pediatric anesthesia. However, based on the anatomical features of pediatric patients, novice residents are expected to have difficulties inserting the device. The objective of this work was to improve the SLIPA insertion by modifying the device.

METHODS

A total of 134 children were randomized into two groups. Anesthesia was standardized among all patients except for the way in which the SLIPA was inserted. One group underwent the conventional method of insertion (Group C), while the modified group received a SLIPA that was bent120° at the 'bridge' point with an intubating stylet (Group M). The primary outcome was insertion success rate, and the secondary outcomes included insertion time, incidence of complications and hemodynamic responses to insertion.

RESULTS

The insertion success rate was significantly higher in Group M than Group C (94% vs. 73%, Χ² = 10.659, P = 0.001). The insertion time for Group M [29.31 (25.91-35.60) seconds] was shorter than for Group C [34.72 (26.81-42.58) seconds] (Z = -2.381, P = 0.017). Trends in heart rate (F = 0.260, P = 0.794), mean blood pressure (F = 0.167, P = 0.683) did not significantly differ between the two groups over time. In terms of complications, we found no significant differences between groups (P > 0.05).

CONCLUSION

The 120° bend improved SLIPA insertion when performed by novice, as reflected by higher insertion success rates and shorter insertion times, with no statistical differences in hemodynamic response to insertion or the incidence rates of complications between the two groups.

Streamlined Liner of the Pharynx Airway: Randomised Comparison of Size Selection Strategies with Regard to Patient Height versus Thyroid Cartilage Width

Introduction

Streamlined Liner of the Pharynx Airway (SLIPA) is a disposable supraglottic airway. There are two strategies to select the size of SLIPA: by height and width of thyroid cartilage. This study compared the utility of the two strategies in selecting the optimal size.

Methods

One hundred forty-two patients were randomly divided into two groups with size selection by height (H) and the maximal width of the thyroid cartilage (T). The SLIPA size was selected by height in group H, and by the width of thyroid cartilage in group T. After inserting SLIPA, the investigator made note of the oropharyngeal leakage pressure (OLP) and the degree of insertion difficulty. We set the OLP as a primary outcome. In cases of an OLP <15 cmH2O, the investigator manipulated the apparatus to try to reposition it. If air still leaked, another attempt was made using a SLIPA one size larger until an OLP >15 cmH2O was achieved in up to three attempts. After insertion, the investigator measured the inspiratory and expiratory tidal volume. Post-operatively, the presence of blood or regurgitated fluid on the device was evaluated.

Results

OLP for group T was higher than that of group H (p=0.009). The need for manipulation and the leak fraction was higher in group H than in group T (p=0.008 and 0.034, respectively). The degree of insertion difficulty, number of trials and incidence of blood and regurgitated fluid on the device were similar between the two groups.

Conclusions

Both the width and height of thyroid cartilage can be used for selecting the optimal SLIPA size. (Hong Kong j.emerg.med. 2015;22:303-311)

A comparison of the effectiveness of the streamlined liner of pharyngeal airway in paralyzed and nonparalyzed patients undergoing gynecological surgery: a randomized trial

STUDY OBJECTIVE

To compare the effectiveness of streamlined liner of pharyngeal airway (SLIPA) in paralyzed and nonparalyzed, anesthetized patients undergoing gynecological surgery.

DESIGN

Prospective randomized double-blind clinical trial.

SETTING

Intraoperative.

PATIENTS

A total of 80 female patients with American Society of Anesthesiologists class I or II and who were undergoing gynecological surgery.

INTERVENTIONS

The patients were randomly allocated to either the nonparalyzed group (group NR, n=40) or the paralyzed group (group R, n=40).

MEASUREMENTS

Oropharyngeal leakage pressure was the primary outcome. Insertion time; number of insertion attempts; success rate at first insertion; involuntary movement; peak inspiratory pressure (PIP); leakage fraction; hemodynamic changes; complications, such as blood tinging, regurgitation, and sore throat; and recovery time were also evaluated for secondary outcomes.

MAIN RESULTS

Oropharyngeal leakage pressure, which is primary outcome, was no difference among the groups. Insertion time, number of insertion attempts, success rate at first insertion, involuntary movement, leakage fraction, hemodynamic changes, and complications were not statistically different among the groups. The PIP in group NR was significantly increased compared to that of group R (P=.002). Recovery time was significantly longer in group R than in group NR (P<.001).

CONCLUSIONS

SLIPA had good performance in both paralyzed and nonparalyzed patients. There was no difference in SLIPA performance or complications irrespective of muscle relaxant use, except decrease in PIP and prolong recovery time in paralyzed patients.

Preheating of streamlined liner of pharyngeal airway (SLIPA) reduced the related complications: a randomized control study

This study was designed to verify whether preheating could decrease the complications that may be associated with the use of streamlined liner of pharyngeal airway (SLIPA). We evaluated the incidence of sore throat, maximum sealing pressure, hoarseness and blood stains after preheating of SLIPA. Eighty patients scheduled for hysteroscopic surgery to whom the SLIPA was considered suitable were randomly allocated to preheating group or control group. The SLIPA in preheating group was placed in the incubator at 42 °C. The control group temperature was 24 °C. The mean maximum sealing pressure and duration of insertion were compared. Patients were interviewed at recovery room about sore throat and other complications. There were statistical differences in incidence of sore throat, severity of sore throat and blood stains between groups. However there was no statistical difference in the maximum sealing pressure. Our results suggest preheating of the SLIPA decreased the complications related with the insertion of SLIPA. Clinical Trials.gov Identifier NCT02539485.

Comparison of the Disposable Streamlined Liner of the Pharynx Airway and the Disposable I-gel in Anaesthetized, Paralyzed Adults: A Randomized Prospective Study

Introduction. This study compared streamlined liner of the pharynx airway (SLIPA) and I-gel noninflatable, single-use, supraglottic airway device (SAD) performance in anesthetized, paralyzed adults. Methods. Eighty adults (ASA physical statuses I–III) who were undergoing elective procedures under general anesthesia with an SAD were enrolled in this prospective, randomized, single-blind study. Subjects were randomly and evenly assigned to the SLIPA or I-gel group for intraoperative airway management. Ease and number of insertions, insertion time, oropharyngeal sealing pressure, hemodynamic response, oxygen saturation (SpO₂), end-tidal CO₂ (EtCO₂), and peri- and postoperative complications were examined. Results. The SLIPA and I-gel devices were successfully inserted in 100% and 95% of subjects, respectively. In two I-gel subjects (5%), ventilation was not possible after two attempts, but a size 55 SLIPA was successfully inserted in both cases. Forty-two and 38 patients were ultimately included in the SLIPA and I-gel groups, respectively. Insertion time was significantly shorter with the SLIPA (11.19 ± 3.03 s) than with the I-gel (15.05 ± 6.37 s, P = 0.003). Oropharyngeal sealing pressure was significantly higher in SLIPA (28.76 ± 3.11 cmH₂O) than in I-gel (25.9 ± 3.65 cmH₂O) subjects (P = 0.001). Blood staining occurred more frequently in SLIPA (n = 8, 19.0%) than in I-gel (n = 5, 13.2%) patients (P < 0.01). Heart rate, mean arterial blood pressure, SpO₂, and EtCO₂ were not significantly different between groups. Conclusion. Although blood staining incidence was higher, SLIPA insertion was easier and faster than I-gel insertion. The SLIPA provided better airway sealing pressure. Both devices had similar mechanical ventilation and oxygenation characteristics and comparable hemodynamic stability. Both noninflatable SADs are useful, but SLIPA rapid insertion and good airway sealing make it an effective alternative to the I-gel.

Role of laryngeal mask airway in laparoscopic cholecystectomy

Laparoscopic cholecystectomy is one of the most commonly performed surgical procedures and the laryngeal mask airway (LMA) is the most common supraglottic airway device used by the anesthesiologists to manage airway during general anesthesia. Use of LMA has some advantages when compared to endotracheal intubation, such as quick and ease of placement, a lesser requirement for neuromuscular blockade and a lower incidence of postoperative morbididy. However, the use of the LMA in laparoscopy is controversial, based on a concern about increased risk of regurgitation and pulmonary aspiration. The ability of these devices to provide optimal ventilation during laparoscopic procedures has been also questioned. The most important parameter to secure an adequate ventilation and oxygenation for the LMA under pneumoperitoneum condition is its seal pressure of airway. A good sealing pressure, not only state correct patient ventilation, but it reduces the potential risk of aspiration due to the better seal of airway. In addition, the LMAs incorporating a gastric access, permitting a safe anesthesia based on these commented points. We did a literature search to clarify if the use of LMA in preference to intubation provides inadequate ventilation or increase the risk of aspiration in patients undergoing laparoscopic cholecystectomy. We found evidence stating that LMA with drain channel achieves adequate ventilation for these procedures. Limited evidence was found to consider these devices completely safe against aspiration. However, we observed that the incidence of regurgitation and aspiration associated with the use of the LMA in laparoscopic surgery is very low.

Laryngeal mask airway without muscle relaxant in femoral head replacement in elderly patients

The number of elderly patients undergoing femoral head replacement surgeries is on the increase. These patients often suffer from comorbidity such as cardiovascular and cerebrovascular complications, which limits the ability of medical teams to employ anesthesia. Thus, alternative methods are required. The aim of this study was to examine the advantage of laryngeal mask airway (LMA) in the absence of muscle relaxant in elderly patients undergoing femoral head replacement operations. Fifty patients (27 males and 23 females) undergoing femoral head replacements were selected for the study between March 2013 and May 2014. The mean value for the age in this group was 74.6±12.5 years. The patients were randomly distributed into two groups of 25. One group was designated as the treatment group and the second group as the control group. For the treatment group, LMA without muscle relaxant was used, and the control group received routine anesthesia. Variations in heart rate (HR), mean arterial pressure (MAP) and oxygen saturation (SPO₂) in the two groups were monitored at different times. Clinical efficacy and muscle relaxation effects were also analyzed. For the treatment group, the HR, MAP and SPO₂ measurements did not reveal any significant variation while these values in the control group demonstrated important dissimilarities. Time to recovery, time to extubation and incidence of throat pain in the treatment group were all markedly decreased as compared to those in control group. The operation time in the treatment group was not significantly different to that of control group. The satisfaction of the muscle relaxation effect in the treatment group was significantly higher than that in the control group while the incidence of adverse reactions was not considerably different. In conclusion, the use of LMA without using muscle relaxant in femoral head replacement surgeries performed on elderly patients showed to be effective and safe.

Airway management evolution - in a search for an ideal extraglottic airway device

Extraglottic airway devices (EADs) are commonly used equipment for airway maintenance during elective procedures under general anaesthesia. They may be used also in other indications such as conduit for tracheal intubation or rescue airway device in prehospital medicine. Current classifications of the EADs lack systematic approach and therefore classification according to the sealing sites and sealing mechanisms is suggested in this review article. Modern EADs are disposable, latex-free devices made of plastic materials most commonly from polyvinylchloride (PVC). The bowl of uncuffed sealers is manufactured from different materials such as thermoplastic elastomers or ethylene-vinyl-acetate co-polymer. EADs create various physical forces exerted on the adjacent tissues which may contribute to different sealing characteristic of particular device or to variable incidence of postoperative complications. Desired features of an ideal EAD involve easy insertion, high insertion success rate even by inexperienced users, protection against aspiration of gastric contents and low incidence of postoperative complications such as sore throat, hoarseness, cough or swallowing difficulties.

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.

Comparison of streamlined liner of the pharynx airway (SLIPA ™) and laryngeal mask airway: a systematic review and meta-analysis

We performed a systematic review to compare the efficacy and safety of the streamlined liner of the pharynx airway and laryngeal mask airway used in adults during general anaesthesia. We included 14 studies with studies with 1273 patients in total. There was no evidence of a difference between the two devices in insertion success rate on the first attempt (13 studies, 1143 patients), insertion time (seven studies, 576 patients), ease of insertion (five studies, 466 patients), oropharyngeal leak pressure (eight studies, 771 patients) and the quality of the fibreoptic view of the larynx through the device (three studies, 281 patients). The relative risk (95% CI) of bloodstaining of the device (nine studies, 859 patients) was 2.09 (1.46-3.00) for the streamlined liner of the pharynx airway compared with the laryngeal mask airway. Other adverse events were comparable. Subgroup analysis suggested that the insertion by novice users might be faster and more successful with the streamlined liner of the pharynx airway than the laryngeal mask airway; however, this was from only two studies and 186 patients. The method of size selection of the streamlined liner of the pharynx airway device might also affect the speed of insertion: choosing according to the width of the patient's thyroid cartilage, rather than height, may produce better results.

Gastric distension with SLIPA versus LMA ProSeal during laparoscopic cholecystectomy: a randomized trial

BACKGROUND

We compared the quantitative clinical performances of the streamlined liner of the pharynx airway (SLIPA) and the ProSeal laryngeal mask airway (LMA ProSeal) regarding intensity of gastric distension in patients undergoing laparoscopic cholecystectomy.

METHODS

A total of 124 anesthetized, paralyzed patients (ASA 1 to 2; aged, 18 to 80 y) were randomly allocated for airway management with the SLIPA or LMA ProSeal. After induction of general anesthesia using total intravenous anesthesia and rocuronium, the intensity of gastric distension was accessed twice by 2 raters, respectively. We also compared the fiberoptic bronchoscopic view of the glottis, the severity of blood stain, and postoperative sore throat.

RESULTS

There were no statistically significant differences between groups for each gastric size. The change of gastric size within the SLIPA group was not statistically significant for both raters. Change within the LMA ProSeal group was significant in rater 2 (P=0.045) and marginally significant for rater 1 (P=0.056). Anatomic fit, complications during emergence, and the severity of blood stain and postoperative sore throat were similar in both groups.

CONCLUSIONS

SLIPA is as efficacious as LMA ProSeal for use in patients without severe complications who are undergoing laparoscopic cholecystectomy.

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.

A novel method for SLIPA™ size selection, for adult patients, on the basis of chamber length

PURPOSE

Nowadays the size of the streamlined liner of the pharynx airway (SLIPA™) is selected by matching the width of the thyroid cartilage of the patient to the widest dimension of the SLIPA™. The objective of this work was to improve the method of selection by matching the distance between the otobasion inferius and the most inferior margin of the cricoid cartilage (O-C) to the length of the SLIPA™ chamber.

METHODS

100 patients (ASAI-II) scheduled to undergo operations under general anesthesia were randomly divided into two groups, group A (size selected by matching O-C with SLIPA™ chamber length, n = 50) and group B (size selected by matching the width of the thyroid cartilage with the widest dimension of the SLIPA™, n = 50). We measured the distance between the nasopharynx and the interarytenoid fold (N-I) and investigated the correlation between O-C and N-I at the neutral head position. Number of attempts, insertion time, blood on the device, leakage, and the need to change sizes were assessed.

RESULTS

A positive correlation (r = 0.68, p < 0.05) was detected between N-I and O-C. Leakage was observed in 6 % (n = 3) of group A patients and in 20 % (n = 10) of group B patients (p < 0.05).

CONCLUSION

Compared with the classic size-selection method, matching the width of the thyroid cartilage with that of the SLIPA™, the size-selection method of matching SLIPA™ chamber length to O-C for adult patients is more accurate.

Comparison of the clinical effectiveness between the streamlined liner of pharyngeal airway (SLIPA) and the laryngeal mask airway by novice personnel

BACKGROUND

The aim of this study was to compare the streamlined liner of the pharynx airway (SLIPA) with the classic laryngeal mask airway when used by novice personnel.

METHODS

There were 114 patients enrolled into this study who underwent general anesthesia were randomly allocated into one of 2 groups; LMA group (n = 57) or SLIPA group (n = 57). After insertion, insertion success rate, insertion time, and hemodynamic responses to insertion were accessed. After surgery, postoperative airway morbidity (sore throat, dysphonia, dysphagia) were evaluated.

RESULTS

The SLIPA was successfully inserted in 96% of patients (55/57) and the LMA in 93% (53/57) (P = 0.408). First attempt success rates were 88% (44/57) and 77% (50/57) in the SLIPA and the LMA (P = 0.142). The successful insertion time in SLIPA group (33.4 ± 11.0 sec) was significantly shorter than that of LMA group (38.8 ± 16.6 sec) (P = 0.048) and the insertion time at the first attempt was also shorter in SLIPA group (31.0 ± 6.3 sec) than LMA group (34.7 ± 8.6 sec) (P = 0.013). There was no statistically significant difference between the two groups in hemodynamic responses and postoperative airway morbidity.

CONCLUSIONS

The SLIPA was similar to the LMA in insertion success rate, hemodynamic response, and postoperative airway morbidity by novice personnel. The insertion time at the first attempt and successful insertion time of the SLIPA were significantly shorter than those of the LMA. Therefore, the SLIPA could be a useful alternative to the LMA as primary SGA for novice personnel.

Comparison of streamlined liner of the pharynx airway (SLIPA™) with the laryngeal mask airway Proseal™ for lower abdominal laparoscopic surgeries in paralyzed, anesthetized patients

Context:

Supraglottic airway devices have been used as an alternative to tracheal intubation during laparoscopic surgery.

Aims:

The study was designed to compare the efficacy of Streamlined Liner of the Pharynx Airway (SLIPA) for positive pressure ventilation and postoperative complications with the Laryngeal Mask Airway ProSeal (PLMA) for patients undergoing lower abdominal laparoscopies under general anesthesia with controlled ventilation.

Settings and Design:

Prospective, crossover randomized controlled trial performed on patients undergoing lower abdominal laparoscopic surgeries.

Methods:

A total of 120 patients undergoing lower abdominal laparoscopic surgeries were randomly allocated into two equal groups; PLMA and SLIPA groups. Number of intubation attempts, insertion time, ease of insertion, and fiberoptic bronchoscopic view were recorded. Lung mechanics data were collected 5 minutes after securing the airway, then after abdominal insufflation. Blood traces and regurgitation were checked for; postoperative sore throat and other complications were recorded.

Statistical Analysis:

Arithmetic mean and standard deviation values were calculated and statistical analyses were performed for each group. Independent sample t-test was used to compare continuous variables exhibiting normal distribution, and Chi-squared test for noncontinuous variables. P value <0.05 was considered significant.

Results:

Insertion time, first insertion success rate, and ease of insertion were comparable in both groups. Fiberoptic bronchoscopic view was significantly better and epiglottic downfolding was significantly lower in SLIPA group. Sealing pressure and lung mechanics were similar. Gastric distension was not observed in both groups. Postoperative sore throat was significantly higher in PACU in PLMA group. Blood traces on the device were significantly more in SLIPA group.

Conclusions:

SLIPA can be used as a useful alternative to PLMA in patients undergoing lower abdominal laparoscopic surgery with muscle relaxant and controlled ventilation.

Effectiveness of the Streamlined Liner of the Pharynx Airway (SLIPA™) in Allowing Positive Pressure Ventilation during Gynaecological Laparoscopic Surgery

The aim of this study was to assess whether the Streamlined Liner of the Pharynx Airway (SLIPA™) performed as well as an endotracheal tube for positive pressure ventilation in gynaecological laparoscopic surgery in the Trendelenburg position. Forty patients (American Society of Anesthesiologists physical status I to III) were randomly divided into two groups: SLIPA (n=20) or endotracheal tube group (n=20). Lung mechanics and severity of postoperative sore throat were assessed in both groups. In the SLIPA group, the oropharyngeal leak pressure was also measured.

There were no significant differences between groups in the lung mechanics. In the SLIPA group, oropharyngeal leak pressure and peak inspiratory pressure increased significantly after gas insufflation compared to 10 minutes after patient positioning in the lithotomy position (P <0.05). The difference between oropharyngeal leak pressure and peak inspiratory pressure (approximately 10 cmH2O throughout the procedure) remained suitable for airway maintenance. The incidence of sore throat was similar in both groups but the severity was less in the SLIPA group 24 hours after surgery (P <0.05). There were no other complications such as regurgitation noted in either group. In the study population, the SLIPA performed as well as an endotracheal tube in allowing positive pressure ventilation without gas leak during gynaecological laparoscopy. The way in which the SLIPA increases its resistance to gas leak as the inspiratory pressure rises may account for this.

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.

The clinical effectiveness of the streamlined liner of pharyngeal airway (SLIPA) compared with the laryngeal mask airway ProSeal during general anesthesia

Background

The aim of this study was to compare the streamlined liner of the pharynx airway (SLIPA), a new supraglottic airway device (SGA), with the laryngeal mask airway ProSeal™ (PLMA) during general anesthesia.

Methods

Sixty patients were randomly allocated to two groups; a PLMA group (n = 30) or a SLIPA group (n = 30). Ease of use, first insertion success rate, hemodynamic responses to insertion, ventilatory efficiency and positioning confirmed by fiberoptic bronchoscopy were assessed. Lung mechanics data were collected with side stream spirometry at 10 minutes after insertion. We also compared the incidence of blood stain, incidence and severity of postoperative sore throat and other complications.

Results

First attempt success rates were 93.3% and 73.3%, and mean insertion time was 7.3 sec and 10.5 sec in PLMA and SLIPA. There was a significant rise in all of hemodynamic response from the pre-insertion value at one minute following insertion of SLIPA. But, insertion of PLMA was no significant rise in hemodynamic response. There was no statistically significant difference in the mean maximum sealing pressure, gas leakage, lung mechanics data, gastric distension, postoperative sore throat and other complication between the two groups. Blood stain were noted on the surface of the device in 40% (n = 12) in the SLIPA vs. 6.7% (n = 2) in the PLMA.

Conclusions

The SLIPA is a useful alternative to the PLMA and have comparable efficacy and complication rates. If we acquire the skill to use, SLIPA may be considered as primary SGA devices during surgery under general anesthesia.

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.

A critique of elective pediatric supraglottic airway devices

In 1988, when the Laryngeal Mask Airway-Classic (Intavent Orthofix, Maidenhead, UK), was introduced there were only two choices of airway management: tracheal tube or facemask. The supraglottic airway, as we now understand the term, did not exist. Yet, 20 years later, we are faced with an ever increasing choice of supraglottic airway devices (SAD). For many SADs, with the exception of the LMA-Classic and LMA-Proseal (Intavent Orthofix, Maidenhead, UK), there is a lack of high quality data of efficacy. The best evidence requires a randomized controlled trial comparing a new device against an established alternative, properly powered to detect clinically relevant differences in clinically important outcomes. Such studies in children are very rare. Safety data is even harder to establish particularly for rare events such as aspiration. Therefore, most safety data comes from extended use rather than high quality evidence which inevitably biases against newer devices. For reason of these factors, claims of efficacy and particularly safety must be interpreted cautiously. This narrative review aims to present the evidence surrounding the use of currently available pediatric SADs in routine anesthetic practice.

Brief review: the Cobra Perilaryngeal Airway (CobraPLA and the Streamlined Liner of Pharyngeal Airway (SLIPA) supraglottic airways

PURPOSE

To summarize the published literature related to two, new supraglottic airways (SGAs): the Cobra Perilaryngeal Airway (CobraPLA) and the Streamlined Liner of Pharyngeal Airway (SLIPA).

SOURCE

We identified original articles, through searches on Medline and PubMed, using the keywords 'Cobra', 'CobraPLA', 'Cobra-PLA', 'PLA', and 'SLIPA'.

PRINCIPAL FINDINGS

Searches identified 28 publications evaluating the CobraPLA, six of which were randomized, controlled trials. Five publications evaluated the SLIPA, two of which were randomized, controlled trials. Studies compared the CobraPLA with a number of SGAs, in regards to both efficacy and safety. While the CobraPLA is comparable to the laryngeal mask airway (LMA) Classic, with respect to insertion times and the incidence and severity of sore throat, the CobraPLA is superior, with respect to airway sealing pressure, and has been used successfully in patients with limited mouth opening and limited head extension. Insertion times, first insertion success rates, recovery times, and hemodynamic responses, associated with insertion of the SLIPA, are similar to those of the LMA Proseal. Although the SLIPA has a unique reservoir chamber to contain regurgitated fluid, the extent of its protection against pulmonary aspiration has not been established in the clinical setting.

CONCLUSION

Both the CobraPLA and the SLIPA are intended for use during short procedures under general anesthesia, and have comparable efficacy and complication rates in comparison to the LMA Classic. Both airways may be considered as primary SGA devices, and the CobraPLA may be also be used as a rescue airway device.

Haemodynamic and Bispectral Index Response to Insertion of the Streamlined Liner of the Pharynx Airway (SLIPA™): Comparison with the Laryngeal Mask Airway

The newly developed supralaryngeal airway Streamlined Liner of the Pharynx Airway (SLIPA™) has been compared successfully to the LMA™, but the haemodynamic response to its insertion has not been evaluated in a randomised study. We compared haemodynamic and Bispectral index(BIS) responses to insertion of the SLIPA™ with classic LMA™ after standardising the anaesthetic technique using BIS to monitor and control the anaesthetic depth. One hundred patients were randomised to receive either a classic LMA™ or SLIPA™ following induction with fentanyl and propofol titrated to a target BIS of 40 and compared heart rate, mean arterial pressure and BIS responses to insertion. There was a significant rise in mean arterial pressure from the pre-stimulus value (73.8 [10.6] mmHg, mean ± SD) at two and three minutes (P <0.05) following insertion of the LMA™ with maximum rise (80.8 [11.5] mmHg) seen at two minutes. There was a significant rise in mean arterial pressure from the pre-stimulus value (73.2 [12.6] mmHg) atone, two, three, four and five minutes (P <0.05) following insertion of the SLIPA™ with maximum rise (86.9 [15.1] mmHg) observed at three minutes. Mean arterial pressure was significantly higher (P <0.05) with SLIPA™ at two, three, four and five minutes. BIS increased significantly (P <0.05) at one, two, three, four and five minutes following insertion of both the devices, but there was no significant difference between the groups. There was a significantly higher (P=0.001) incidence of blood on the device with the SLIPA™ (20/50 vs. 6/50 with LMA™). Thus, insertion of SLIPA™ causes significantly higher blood-pressure response but similar BIS response compared to the LMA™.

Anesthesia for outpatient gynecologic surgery

PURPOSE OF REVIEW

Anesthesia care for patients undergoing ambulatory gynecologic surgery has improved incrementally over the past few years. Emphasis has evolved beyond the safe provision of care, because this has largely been achieved. Comfort, speed, and efficiency have taken on new importance.

RECENT FINDINGS

Many changes relate to improvements in non-narcotic analgesic techniques and use of various supralaryngeal airways, such as the ProSeal LMA. Also, use of depth of anesthesia monitors and administration of potent short-acting beta-blockers and narcotics to control hemodynamic variables are examples of new anesthesia developments well applied to ambulatory gynecologic cases. Finally, anesthesia care is changing in some instances because surgical techniques are advancing, such as hysteroscopy, and can now be done in an office with little or no anesthesia.

SUMMARY

Local anesthetic use in gynecologic laparoscopy appears to improve postoperative pain control modestly, especially when given into the peritoneal cavity. Supralaryngeal airways, such as ProSeal LMA, appear to provide effective ventilation in laparoscopy, although their ability to protect against aspiration is unclear. The speed and comfort of emergence, recovery, and discharge may be improved by consciousness monitoring during general anesthesia and by drugs intended to modulate hemodynamics.

The effectiveness and patient comfort of the novel streamlined pharynx airway liner (SLIPA) compared with the conventional laryngeal mask airway in ophthalmic surgery

BACKGROUND

The novel, disposable streamlined pharynx airway liner (SLIPA) has recently been introduced into clinical practice. It has no inflatable cuff, because the shape of the SLIPA closely resembles the anatomy of the pharynx.

METHODS

We compared the SLIPA with the conventional laryngeal mask airway (LMA) regarding handling, safety, sealing of the pharynx, and patient comfort in 124 adult patients (ASA I-III) undergoing ophthalmic surgery under general anesthesia.

RESULTS

Insertion of the SLIPA was straightforward in 88%, slightly difficult in 10%, and obviously difficult in 0% of cases. The SLIPA could not be inserted in 2% of patients. In the LMA group, insertion was straightforward in 90%, slightly difficult in 8%, obviously difficult in 2%, and a failure in 0% of patients. Maximum seal pressure was 24 +/- 6 mm H2O with the SLIPA and 24 +/- 4 mm H2O with the LMA. Gastric air insufflation was noticed in 19% of patients in the SLIPA group and 3% in the LMA group (P < 0.05). No regurgitation of gastric contents was observed. Removal of the airway was uneventful in all cases. Blood traces were noted on the surface of the device in 20% in the SLIPA versus 11% (n.s.) in the LMA group. Complaints of a sore throat were recorded in 2% vs. 14% in the SLIPA and the LMA group, respectively.

CONCLUSION

The SLIPA is a useful alternative to the conventional LMA in patients undergoing minor surgery. However, it is associated with a higher incidence of gastric air insufflation, which may increase the risk of aspiration.