Streamlined Liner Of The Pharynx Airway Research Articles

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

PurposeThe 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. DesignThis study is a systematic review and meta-analysis. MethodsTwo 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. FindingsA 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). ConclusionsBoth 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.

Logistic regression analysis of relationship among multiple factors and oropharynx injury in anesthetized patients without using muscle relaxants

Objective To evaluate relationship among oropharynx injury and a number of factors during general anesthesia by a binary Logistic regression, we aim to clinically instruct selecting appropriate sizes of laryngeal mask and improve streamlined liner of the pharynx air-way (SLIPA) laryngeal mask insertion technology. Methods Two hundred and eighty eight patients between July 2014 to May 2015 who were undergoing distal extremities open reduction and internal fixation were enrolled in this study. An identical laryngeal mask general anesthesia combined with nerve block was used in all patients, spontaneous respiration was maintained during surgery. The dependent variable is oropharynx injury while 6 independent variables including climax of resistance, shaping of SLIPA, help from assistants, body weight, selected SLIPA sizes according to the width of oropharynx, body weight, whether small sizes were used, etc. All the factors entered into the final model of the stepwise logistic regression analysis were included in a separate Logistic regression model. Logistic regression was performed by PASW Statistics 18.0 statistical software to investigate possible associations between oropharynx injury as dependent factor and multiple independent factors. Also, the weight of each independent variable is estimated. Results Univariate analyses were performed and showed three factors leading to oropharynx injury during SLIPA laryngeal mask general anesthesia, including climax of resistance, shaping of SLIPA, whether SLIPA sizes were selected according to the width of oropharynx or not (P<0.01). Binary Logistic regression analyses results showed a significant positive correlation between oropharynx injury and climax of resistance, shaping of SLIPA, whether SLIPA size were selected according to the width of oropharynx, whether laryngeal small sizes were used. Peak resistance above 32 N during SLIPA insertion could cause 56 times higher risk of oropharynx injury than the risk when the resistance below 32 N. Inserting SLIPA without shaping could cause 22 times higher risk of oropharynx injury than risk of the opposite. Choosing SLIPA size without pre-measuring the width of the oropharynx caused 7.6 times higher risk than the risk of the opposite. Choosing relatively bigger SLIPA size could cause 4.3 times higher risk than the risk of smaller size. Conclusions Oropharyngeal hemorrhage caused by insertion of SLIPA is notably related to the high resistance during the insertiong process. Shaping SLIPA, selecting SLIPA size according to the width of oropharynx, and choosing smaller size can reduce the risk of oropharyngeal bleeding and injury in anesthetized patients without muscle relaxants. Key words: Logistic regression; Streamlined liner of pharyngeal airway; Anesthesia, general; Oropharynx; Injury

Half-effective target effect-site concentration of sufentanil inhibiting responses to insertion of SLIPA when combined with propofol given by target-controlled infusion

Objective To determine the half-effective target effect-site concentration(EC50)of sufentanil inhibiting responses to insertion of Streamlined Liner of the Pharynx Airway(SLIPA)when combined with propofol given by target-controlled infusion(TCI). Methods Twenty-eight patients, aged 35-55 yr, with body mass index<30 kg/m2, of American Society of Anesthesiologists physical status Ⅰ or Ⅱ, scheduled for elective hysteroscopic surgery, were selected.Sufentanil was administered by TCI at a concentration for 4 min, and then propofol was given by TCI at a target effect-site concentration of 4 μg/ml.When the patients lost consciousness(bispectral index value<60)and the corresponding target effect-site concentrations of two drugs were achieved, SLIPA was inserted.Using the up-and-down sequential trial, the target effect-site concentration of sufentanil was determined according to patient′s responses to SLIPA insertion.The initial target effect-site concentration of sufentanil was 0.3 ng/ml, and the ratio between the two successive concentrations was 1.1.The EC50 and 95% confidence interval of sufentanil inhibiting responses to SLIPA insertion were calculated by using Dixon-Mood formula. Results The EC50 of sufentanil inhibiting responses to SLIPA insertion was 0.17 ng/ml, and the 95% confidence interval was 0.15-0.19 ng/ml. Conclusion When combined with propofol(target effect-site concentration 4 μg/ml)given by TCI, the EC50 of sufentanil inhibiting responses to SLIPA insertion is 0.17 ng/ml. Key words: Sufentanil; Propofol; Laryngeal masks; Dose-response relationship, drug; Drug delivery systems

Pre-warming the Streamlined Liner of the Pharynx Airway (SLIPA) improves fitting to the laryngeal structure: a randomized, double-blind study.

BackgroundThe Streamlined Liner of the Pharynx Airway (SLIPA), a type of supraglottic airway, has a non-inflatable cuff that softens at body temperature to fit the laryngeal structure. We investigated whether pre-warming of SLIPA to body temperature may improve insertion parameters.MethodsNinety adult patients were assigned equally randomized to either Group W or Group R. Anesthesia was induced using propofol, fentanyl, and rocuronium. In Group W, the SLIPA was warmed to 37 ° C before insertion, whereas in Group R, it was inserted at room temperature. The insertion time, oropharyngeal leak pressure, postoperative throat pain, blood staining, regurgitation, number of attempts at insertion, and difficulty of insertion were compared between the two groups.ResultsThe insertion time was shorter in Group W than in Group R (3.60 [3.15–4.06] s vs. 6.00 [4.45–7.50] s; P < 0.001). Oropharyngeal leak pressure from the time of insertion until 3 min after insertion was significantly higher in Group W than in Group R (P < 0.05). Postoperative throat pain, measured using the visual analog scale, was lower in Group W than in Group R (0.00 [0.00–2.50] vs. 2.00 [0.00–4.50]; P = 0.006). The difficulty of insertion was lower in Group W than in Group R (P < 0.004). There were no significant differences in terms of blood staining, regurgitation, and number of attempts.ConclusionsPre-warming the SLIPA to body temperature has significant benefits compared to maintaining the device at room temperature. Specifically, insertion was easier, both insertion and fitting to the laryngeal structure could be performed more quickly, and the incidence of sore throat was reduced.Trial registrationClinical Research Information Identifier NCT01209000

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 &lt;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 &gt;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)

Application of the streamlined liner of the pharynx airway and the proseal laryngeal mask airway in elderly patients undergoing laparoscopic cholecystectomy

Objective To compare the efficacy of the streamlined liner of the pharynx airway (SLIPA) and the proseal laryngeal mask airway (PLMA) in airway management in elderly patients undergoing laparoscopic cholecystectomy. Methods One hundred and twenty patients aged 60-75 years with American Society of Anesthesiologists (ASA) grade Ⅰ or Ⅱ undergoing laparoscopic cholecystectomy were randomly divided into three groups: the endotracheal intubation group (Group T, n=40), the SLIPA group (Group S, n=40) and the PLMA group (Group P, n=40). Endotracheal intubation and laryngeal mask airway insertion were conducted after induction of anesthesia. All the patients were ventilated with intermittent positive pressure ventilation. Mean arterial pressure and heart rate were recorded at before induction (T0), successful insertion (T1), ten minutes after pneumoperitoneum (T2), successful extubation (T3), and ten minutes after extubation (T4). The rate of successful placement at first attempt, time taken for placement, airway sealing pressure, and side effects were recorded. The incidences of post-extubation cough, backflow, aspiration, larynogospasm, bleeding, gastric distension and sore throat within 2 days after intubation were also recorded. Results The successful rates of insertion were 92.5%, 92.5%, 95.0%, respectively, at first attempt and 100.0% at second attempt in the three groups (χ2=0.268, P 0.05). There was no significant difference in post-extubation complications, including backflow, aspiration, laryngospasm and gastric distension (t=0.321, P>0.05), among the three groups, but incidences of post-extubation cough and pharyngalgia were higher in Group T than in Group S and Group P (χ2=26.674, 10.568, P<0.05). Conclusions SLIPA and PLMA can both provide adequate ventilation during operation, with few complications. SLIPA placement is the easiest, while PLMA has good airway sealing and thus is more suitable for elderly patients undergoing laparoscopic cholecystectomy. Key words: Laryngeal masks; Respiration, artificial; Cholecystectomy, laparoscopy

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.

Evaluation of mivacurium-induced release of histamine in patients undergoing general anesthesia

Objective To evaluate mivacurium-induced release of histamine in the patients undergoing general anesthesia.Methods Eighty patients of both sexes,aged 19-58 yr,weighing 42-75 kg,of ASA physical status Ⅰ or Ⅱ,undergoing ureteroscopy under general anesthesia,were randomly divided into 2 groups (n =40 each) using a random number table:rocuronium group (group R) and mivacurium group (group M).Anesthesia was induced with iv midazolam 0.04 mg/kg,fentanyl 3 μg/kg,etomidate 0.3 mg/kg,and mivacurium 0.20 mg/kg (group M) or rocuronium 0.75 mg/kg (group R).Streamlined liner of the pharynx airway (SLIPA) was inserted for mechanical ventilation.PET CO2 was maintained at 35-40 mmHg.Anesthesia was maintained with fentanyl and propofol.Before muscle relaxant administration,at 3 min after muscle relaxant administration and at 5 min after insertion of SLIPA,venous blood samples were collected for determination of plasma histamine concentrations (by HPLC) and the histamine release was classified.Results Compared with group R,the plasma histamine concentration and histamine release were increased at 3 min after muscle relaxant administration in group M.No fatal responses caused by histamine release were found in the two groups.Conclusion Although mivacurium induces release of histamine,it can still be safely used for the patients undergoing ureteroscopy under general anesthesia. Key words: Androstanols ; Histamine ; Anesthesia, general

Gastric Distension With SLIPA Versus LMA ProSeal During Laparoscopic Cholecystectomy

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

Comparative assessment of the easiness and speed of insertion of three supraglottic airway devices - A manikin study -

Purpose : This study was designed to compare the easiness and speed of insertion of three supraglottic airway devices(SADs) in a manikin setting. Methods : Three different SADs - Laryngeal Mask Classic(cLMA), I-gel and Streamlined Liner of the Pharynx Airway(SLIPA) were applied. One hundred and nineteen paramedical students with(group H) or without (group L) previous airway experience were taught brief manikin training about the use of the cLMA, I-gel and SLIPA. The students inserted each device in a randomized order. Time to effective ventilation was recorded in seconds from holding the device to the first chest inflation. Success was determined as adequate chest wall movement. Results : The insertion attempts were lesser in I-gel() and SLIPA() than cLMA(, p), followed by the SLIPA() and cLMA(, p

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.

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.

Efficacy of laryngeal mask airway Supreme and Streamlined Liner of the Pharynx Airway in patients undergoing general anesthesia

Objective To compare the efficacy of laryngeal mask airway Supreme （LMAS） and Streamlined Liner of the pharynx Airway （SLIPA） in patients undergoing general anesthesia. Methods Eighty ASA I or II patients aged 18-70 yr weighing 45-80 kg undergoing general anesthesia were randomly divided into 2 groups （n = 40 each）： group LMAS and group SLIPA. Pharyngeal airway was inserted after induction of anesthesia with fentanyl 3 ug/kg and propofol 2.0-2.5 mg/kg. MAP, HR, number of insertion, rate of successful placement at first attempt, placement time, airway sealing pressure, peak and mean airway pressure and side effects were recorded. Results There were no significant differences in MAP, HR and rate of successful placement at first attempt between the two groups. The placement time was significantly longer, the airway sealing pressure lower and the incidence of side effects higher in SLIPA group than in LMAS group. There was no significant difference in the peak and mean airway pressure between the 2 groups. Conclusion Both LMAS and SLIPA can assure good airway sealing and adequate ventilation. The complication is rare. The efficacy of LMAS is better. Key words: Laryngeal mask ; Respiration, artificial

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

BackgroundThe 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.MethodsSixty 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.ResultsFirst 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.ConclusionsThe 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.

Supraglottic airways and pulmonary aspiration: the role of the drain tube

Several methods have already been proposed for the insertion of supraglottic devices. A study in this issue of the Journal describes a technique involving the prior insertion of a bougie into the upper esophagus over which the drain tube of the ProSeal laryngeal mask airway (PLMA) can be guided. Compared with the use of the metal introducer provided by the manufacturer, this method—with the drain tube—provides better positioning of the PLMA. It is worth noting that the authors concluded that the bougie technique is better because it allows alignment of the tip of the drain tube and the esophageal opening in a more predictable manner, not because the insertion time is shorter or the performance as a ventilatory device is improved. In fact, the bougie technique requires more time, more steps, and the use of a laryngoscope. Many clinicians will argue that the insertion strategy suggested by the authors of this study and others before them unnecessarily complicates a technique considered both simple and effective; therefore, they will likely be reluctant to adopt the technique on a routine basis. This is a paradoxical situation since many anesthesiologists view the incorporation of technical changes designed to prevent pulmonary aspiration to supraglottic devices as a significant improvement. It is worth mentioning that developers of supraglottic airways have long been concerned about pulmonary aspiration and remain attentive to its prevention. The original laryngeal mask, now called Classic, is equipped with an inflatable cuff that is designed not only to provide an adequate airway seal, but also to obstruct the esophagus in order to reduce the risk of gastric contents reaching the laryngeal opening. Other devices also include an inflatable cuff (King-LT laryngeal tube) or feature components of various shapes and sizes (PAXpress, CobraPLA), all designed to occlude the upper esophagus. Another device, the SLIPA (Streamlined Liner of the Pharynx Airway), includes a reservoir designed to collect regurgitated gastric contents. In recent years, however, the most commonly observed tendency in the design of supraglottic airways is the incorporation of a lumen designed to drain secretions from the digestive tract. Some manufacturers achieved this by modifying the design of existing devices, thus resulting in the development of the PLMA, the Supreme laryngeal mask, or the King laryngeal tube (King LTS-D). Others developed new devices, for instance, the I-Gel or the EasyTube. This strong interest in supraglottic devices offering a separate lumen to the digestive tract even led some authors to assess the use of the venerable Combitube for routine airway management during anesthesia. What evidence or arguments led manufacturers to opt for the integration or addition of a drain tube on their devices? We note that the approach is largely theoretical. Indeed, it is difficult to demonstrate that supraglottic airways without access to the digestive tract are responsible for a significant increase in pulmonary aspiration episodes during general anesthesia. Studies involving large patient populations, including some performed in populations traditionally considered at risk, such as Cesarean delivery patients, do not suggest that these devices are associated with a high incidence of clinically significant episodes of aspiration. Other studies involving indirect measures, such as pharyngeal pH or the use of dye (methylene blue), show that the separation provided by supraglottic devices between the digestive tract and the airway is not perfect. On the other hand, we have known for a long time that P. Drolet, MD (&) Departement d’anesthesiologie, Hopital MaisonneuveRosemont, Universite de Montreal, 5415, boul. l’Assomption, Montreal, QC H1T 2M4, Canada e-mail: pdrolet@aei.ca

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) at one, 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.

Randomized comparison of the SLIPA (Streamlined Liner of the Pharynx Airway) and the SS‐LM (Soft Seal Laryngeal Mask) by medical students

The aim of the study was to compare the Streamlined Liner of the Pharynx Airway (SLIPA; Hudson RCI), a new supraglottic airway device, with the Soft Seal Laryngeal Mask (SS-LM; Portex) when used by novices. Thirty-six medical students with no previous airway experience, received manikin training in the use of the SLIPA and the SS-LM. Once proficient, the students inserted each device in randomized sequence, in two separate patients in the operating theatre. Only two insertion attempts per patient were allowed. Students were assessed in terms of: device preference; success or failure; success at first attempt and time to ventilation. Sixty-seven per cent of the students preferred to use the SLIPA (95% confidence interval 49-81%). The SLIPA was successfully inserted (one or two attempts) in 94% of patients (34/36) and the SS-LM in 89% (32/36) (P = 0.39). First attempt success rates were 83% (30/36) and 67% (24/36) in the SLIPA and SS-LM, respectively (P = 0.10). Median time to ventilation was shorter with the SLIPA (40.6 s) than with the SS-LM (66.9 s) when it was the first device used (P = 0.004), but times were similar when inserting the second device (43.8 s vs 42.9 s) (P = 0.75). In the present study novice users demonstrated high success rates with both devices. The SLIPA group achieved shorter times to ventilation when it was the first device they inserted, which might prove to be of clinical significance, particularly in resuscitation attempts. Although the Laryngeal Mask has gained wide recognition for use by both novice users and as a rescue airway in failed intubation, the data presented here suggest that the SLIPA might also prove useful in these areas.