Comparison of the laryngeal mask (LMA™) and laryngeal tube (LT®) with the new perilaryngeal airway (CobraPLA®) in short surgical procedures

Cobra-PLA provides higher oropharyngeal leak pressure than LMA-Classic and LMA-Unique: A meta-analysis with 22 studies

Cobra Perilaryngeal Airway (Cobra-PLA) is a relatively new single-use supraglottic device employed during general anesthesia. This meta-analysis includes randomized controlled trials (RCTs) yielding extensive comparison results among Cobra-PLA, Laryngeal Mask Airway (LMA)-Classic, and LMA-Unique.Two authors performed searches in EMBASE, CENTRAL, PubMed, and ScienceDirect to identify RCTs that compared Cobra-PLA with LMA-Classic and with LMA-Unique in patients undergoing general anesthesia. Both random- and fixed-effects models were used. Begg's funnel plot was used to evaluate publication bias.Twenty-two RCTs with a total of 1845 patients were included. Cobra-PLA offered significantly higher oropharyngeal leak pressure than LMA-Classic [mean difference (MD) = 3.56 (1.56, 5.55), P = .0005] and LMA-Unique [MD = 4.44 (2.12, 6.76), P = .0002]. First-insertion success rate, ease of insertion, insertion time, and reported complications among Cobra-PLA, LMA-Classic, and LMA-Unique were similar.Compared with the commonly used LMA-Classic and LMA-Unique, Cobra-PLA provides superior airway sealing.

Comparison Between the Cobra Perilaryngeal Airway and Laryngeal Mask Airways Under General Anesthesia: A Systematic Review and Meta-analysis

The complication rate and efficacy of the Cobra Perilaryngeal Airway (CobraPLA) and laryngeal mask airways (LMAs®) have been evaluated in the published literature, but the conclusions have been inconsistent. The aim of this systematic review and meta-analysis was thus to assess the performance of the CobraPLA and LMAs under general anesthesia. We searched PubMed, Embase, and the Cochrane Library for randomized controlled trials comparing the CobraPLA with LMAs under general anesthesia. The LMAs used for comparison were the classic LMA (CLMA) and the unique LMA (ULMA). The random effect model was used if heterogeneity was observed, otherwise the fixed effect model was used. Seventeen randomized controlled trials were included; number of studies analyzed for each result are different and were up to 10. The current result suggests that no significant difference between the devices in the insertion success rate at the first attempt. The success rate of first insertion of the CobraPLA was not different from the rates for the CLMA and the ULMA (relative risk: 0.95, 95% confidence interval [CI], 0.91-1.00). CobraPLA insertion was not different from CLMA and ULMA insertion. The CobraPLA provided an oropharyngeal leak pressure higher than that provided by the CLMA (weight mean difference: 3.90, 95% CI, [1.59-6.21] cmH2O) and ULMA (weight mean difference: 6.57, 95% CI, [4.30-8.84] cmH2O). We also found a higher likelihood of blood staining in the airway with the CobraPLA than with the CLMA. In our research, the principal finding of our meta-analysis is that the success rate of first insertion of the CobraPLA was not different from the rate for each of the CLMA and the ULMA, which featured a short learning curve implying its ease of insertion. There was also no significant difference in the incidence of the best view (with a score of 4) obtained with the CobraPLA compared with the other 2 devices. The CobraPLA does seem to be superior to the CLMA and ULMA in providing a higher oropharyngeal leak pressure. The data were insufficient to establish differences in airway adverse events between the groups except for blood staining in the devices, although mucosal trauma occurred more frequently with the Cobra PLA device than with the CLMA and the ULMA.

Blind Intubation through Self-pressurized, Disposable Supraglottic Airway Laryngeal Intubation Masks

Background

Supraglottic airway devices commonly are used for securing the airway during general anesthesia. Occasionally, intubation with an endotracheal tube through a supraglottic airway is indicated. Reported success rates for blind intubation range from 15 to 97%. The authors thus investigated as their primary outcome the fraction of patients who could be intubated blindly with an Air-Qsp supraglottic airway device (Mercury Medical, USA). Second, the authors investigated the influence of muscle relaxation on air leakage pressure, predictors for failed blind intubation, and associated complications of using the supraglottic airway device.

Methods

The authors enrolled 1,000 adults having elective surgery with endotracheal intubation. After routine induction of general anesthesia, a supraglottic airway device was inserted and patients were ventilated intermittently. Air leak pressure was measured before and after full muscle relaxation. Up to two blind intubation attempts were performed.

Results

The supraglottic airway provided adequate ventilation and oxygenation in 99% of cases. Blind intubation succeeded in 78% of all patients (95% CI, 75 to 81%). However, the success rate was inconsistent among the three centers (P < 0.001): 80% (95% CI, 75 to 85%) at the Institute of Anesthesia and Pain Therapy, Kantonsspital Winterthur, Winterthur, Switzerland; 41% (95% CI, 29 to 53%) at the Department of Anesthesiology and Intensive Therapy, Medical University of Lodz, Lodz, Poland; and 84% (95% CI, 80 to 88%) at the Institute of Anesthesiology, University Hospital Zurich, Zurich, Switzerland. Leak pressure before relaxation correlated reasonably well with air leak pressure after relaxation.

Conclusions

The supraglottic airway device reliably provided a good airway and allowed blind intubation in nearly 80% of patients. It is thus a reasonable initial approach to airway control. Muscle relaxation can be used safely when unparalyzed leak pressure is adequate.

Insertion Success of the Laryngeal Tube in Emergency Airway Management

Background. Emergency airway management (AM) is a priority when resuscitating critically ill or severely injured patients. The goal of this study was to determine the success rates of LT insertion during AM. Methods. Studies that included LT first-pass insertion (FPI) and overall-pass insertion (OPI) success by emergency medical services and in-hospital providers performing AM for emergency situations as well as for scheduled surgery published until July 2014 were searched systematically in Medline. Results. Data of 36 studies (n = 1,897) reported a LT FPI success by physicians of 82.5% with an OPI success of 93.6% (p < 0.001). A cumulative analysis of all 53 studies (n = 3,600) led to FPI and OPI success of 80.1% and 92.6% (p < 0.001), respectively. The results of 26 studies (n = 2,159) comparing the LT with the laryngeal mask airway (LMA) demonstrated a FPI success of 77.0 versus 78.7% (p = 0.36) and an OPI success of 92.2 versus 97.7% (p < 0.001). Conclusion. LT insertion failed in the first attempt in one out of five patients, with an overall failure rate in one out of 14 patients. When compared with the LT, the LMA had a cumulative 5.5% better OPI success rate.

Comparing the Laryngeal Mask Airway, Cobra Perilaryngeal Airway and Face Mask in Children Airway Management

OBJECTIVE

We compared the effects of the laryngeal mask airway (LMA), face mask and Cobra perilaryngeal airway (PLA) in the airway management of spontaneously breathing paediatric patients undergoing elective inguinal surgery.

METHODS

In this study, 90 cases of 1-14-year-old children undergoing elective inguinal surgery were scheduled. The patients were randomly divided into three groups. Anaesthesia was provided with sevoflurane and 50%-50% nitrous oxide and oxygen. After providing an adequate depth of anaesthesia, supraglottic airway devices were inserted in the group I and II patients. The duration and number of insertion, haemodynamic parameters, plateau and peak inspiratory pressure and positive end-expiratory pressure of the patients were recorded preoperatively, after induction and at 5, 10, 15 and 30 min peroperatively.

RESULTS

There were no statistical differences between the groups in terms of haemodynamic parameters (p>0.05). In group II, instrumentation success was higher and instrumentation time was shorter than group II. The positive end-expiratory pressure and plateau and peak inspiratory pressure values were statistically lower in group II (p<0.05).

CONCLUSION

We concluded that for airway safety and to avoid possible complications, LMA and Cobra PLA could be alternatives to face mask and that the Cobra PLA provided lower airway pressure and had a faster and more easy placement than LMA.

Complications Associated with the Use of Supraglottic Airway Devices in Perioperative Medicine

Supraglottic airway devices are routinely used for airway maintenance in elective surgical procedures where aspiration is not a significant risk and also as rescue devices in difficult airway management. Some devices now have features mitigating risk of aspiration, such as drain tubes or compartments to manage regurgitated content. Despite this, the use of these device may be associated with various complications including aspiration. This review highlights the types and incidence of these complications. They include regurgitation and aspiration of gastric contents, compression of vascular structures, trauma, and nerve injury. The incidence of such complications is quite low, but as some carry with them a significant degree of morbidity the need to follow manufacturers' advice is underlined. The incidence of gastric content aspiration associated with the devices is estimated to be as low as 0.02% with perioperative regurgitation being significantly higher but underreported. Other serious, but extremely rare, complications include pharyngeal rupture, pneumomediastinum, mediastinitis, or arytenoid dislocation. Mild short-lasting adverse effects of the devices have significantly higher incidence than serious complications and involve postoperative sore throat, dysphagia, pain on swallowing, or hoarseness. Devices may have deleterious effect on cervical mucosa or vasculature depending on their cuff volume and pressure.

Comparison of the Supraglottic Airway Devices Classic, Fastrach and Supreme Laryngeal Mask Airway: A Prospective Randomised Clinical Trial of Efficacy, Safety and Complications

OBJECTIVE

This prospective randomised study was designed to compare the Laryngeal Mask Airway (LMA) Classic, LMA Fastrach and LMA Supreme regarding ease of insertion and insertion time as primary outcomes and reposition, success rate of trials, effects on haemodynamic parameters, provision of an adequate and safe airway, amount of leakage and oropharyngeal and systemic complications as secondary outcomes.

METHODS

In this clinical trial, 90 patients aged 18-70 years of American Society of Anesthesiologists (ASA) group I-II were randomised into three groups as providing airway via LMA Classic, LMA Fastrach or LMA Supreme instead of tracheal intubation. No muscle relaxant was used. The allocated LMA was inserted by the same anaesthetist; bispectral index (BIS) was between 40% and 60%.

RESULTS

There was no statistical difference among the groups regarding the ease of insertion and insertion time as primary outcomes; the incidence of repositioning during placement was significantly higher in the LMA Classic group than that in other groups (p<0.05) and the rates of bloodstain on the device as well as oropharyngeal mucosal oedema were higher in the LMA Fastrach group than those in other groups (p<0.05) as secondary outcomes.

CONCLUSION

We suggest that LMA Classic, LMA Supreme and LMA Fastrach had similar effectiveness regarding efficiency and airway safety. However, LMA Supreme seems to be more advantageous as it is more appropriate for fewer oropharyngeal complications and there was no repositioning.

Comparison of Four Different Supraglottic Airway Devices in Terms of Efficacy, Intra-ocular Pressure and Haemodynamic Parameters in Children Undergoing Ophthalmic Surgery

OBJECTIVE

The aim of this study was to compare insertion parameters of four different types of supraglottic airway devices (SGAD) (Classic LMA, I-gel LMA, Proseal LMA, Cobra PLA) in children undergoing ophthalmic surgery and to determine the effect on intra-ocular pressure (IOP) and haemodynamic responses during insertion.

METHODS

Sixty American society of Anesthesiologists (ASA) I-II children aged 1-10 years undergoing extra-ocular ophthalmic surgery were randomly divided into four groups (Group LMA, Group I-gel LMA, Group PLMA and Group CPLA) in this prospective, randomised study. Anaesthesia was induced with decreasing sevoflurane concentrations (8%-2%) in a mixture of 50% N2O-O2. All SGADs were inserted under deep anaesthesia. The characteristics of insertion (number of attempts, ease and time), oropharyngeal leak pressure (OLP) and complications were recorded. IOP in both eyes, heart rate (HR), mean arterial pressure (MAP) and EtCO2 were measured before and 2 and 5 min after insertion of the SGADs.

RESULTS

There was no difference between the groups in terms of the characteristics of insertion. The mean IOP did not increase significantly in all groups. MAP and HR changes were similar among the groups during follow-up. In all groups, HR increased 2 min after insertion (statistically insignificant) and returned to the baseline value 5 min after insertion. A statistically significant correlation was seen between HR increase and IOP values before and after insertion of the SGADs (p=0.006, correlation coefficient=0.352). Desaturation was seen in one patient in Groups LMA, PLMA and CPLA, and laryngospasm was seen in two patients in Group CPLA and in one patient in Group LMA.

CONCLUSION

It was seen that during insertion of Classic LMA, I-gel LMA, Proseal LMA and Cobra PLA, IOP did not increase and haemodynamic stability was maintained in children undergoing extra-ocular ophthalmic surgery.

Success rate of airway devices insertion: laryngeal mask airway versus supraglottic gel device

Background

The main important method for airway management during anesthesia is endotracheal intubation. Laryngeal mask airway (LMA) and supraglottic gel device (I-Gel) are considered alternatives to endotracheal tube.

Objectives

This study sought to assess the success rate of airway management using LMA and I-Gel in elective orthopedic surgery.

Patients and Methods

This single-blinded randomized clinical trial was performed on 61 ASA Class 1 and 2 patients requiring minor orthopedic surgeries. Patients were randomly allocated to two groups of LMA and I-Gel. Supraglottic airway placement was categorized into three groups regarding the number of placement attempts, i.e. on the first, second, and third attempts. Unsuccessful placement on the third attempt was considered failure and endotracheal tube was used in such cases. The success rate, insertion time, and postoperative complications such as bleeding, sore throat, and hoarseness were recorded.

Results

In the I-Gel group, the success rate was 66.7% for placement on the first attempt, 16.7% for the second, and 3.33% for the third attempt. In the LMA group, the success rates were 80.6% and 12.9% for the first and second attempts, respectively. Failure in placement occurred in four cases in the I-Gel and two cases in LMA groups. The mean insertion time was not significantly different between two groups (21.35 seconds in LMA versus 27.96 seconds in I-Gel, P = 0.2). The incidence of postoperative complications was not significantly different between study groups.

Conclusions

I-Gel can be inserted as fast as LMA with adequate ventilation in patients and has no major airway complications. Therefore, it could be a good alternative to LMA in emergency airway management or general anesthesia.

Comparison of the air-Q intubating laryngeal airway and the cobra perilaryngeal airway as conduits for fiber optic-guided intubation in pediatric patients

BACKGROUND

One of the methods proposed in cases of difficult airway management in children is using a supraglottic airway device as a conduit for tracheal intubation. The aim of this study was to compare the efficacy of the Air-Q Intubating Laryngeal Airway (Air-Q) and the Cobra Perilaryngeal Airway (CobraPLA) to function as a conduit for fiber optic-guided tracheal intubation in pediatric patients.

MATERIALS AND METHODS

A total of 60 children with ages ranging from 1 to 6 years, undergoing elective surgery, were randomized to have their airway managed with either an Air-Q or CobraPLA. Outcomes recorded were the success rate, time and number of attempts required for fiber optic-guided intubation and the time required for device removal after intubation. We also recorded airway leak pressure (ALP), fiber optic grade of glottic view and occurrence of complications.

RESULTS

Both devices were successfully inserted in all patients. The intubation success rate was comparable with the Air-Q and the CobraPLA (96.7% vs. 90%), as was the first attempt success rate (90% vs. 80%). The intubation time was significantly longer with the CobraPLA (29.5 ± 10.9 s vs. 23.2 ± 9.8 s; P < 0.05), but the device removal time was comparable in the two groups. The CobraPLA showed a significantly higher ALP (20.8 ± 5.2 cmH2O vs. 16.3 ± 4.5 cmH2O; P < 0.001), but the fiber optic grade of glottic view was comparable with the two devices. The CobraPLA was associated with a significantly higher incidence of blood staining of the device on removal and post-operative sore throat.

CONCLUSION

Both the Air-Q and CobraPLA can be used effectively as a conduit for fiber optic-guided tracheal intubation in children. However, the Air-Q proved to be superior due to a shorter intubation time and less airway morbidity compared with the CobraPLA.

The effect of cuff pressure on postoperative sore throat after Cobra perilaryngeal airway

PURPOSE

The cuff volume of the Cobra perilaryngeal airway (CobraPLA) is larger than that of other alternative airway devices and makes it difficult to predict the effect of cuff pressure on the perilaryngeal mucosa. We tested the hypothesis that adjustment of the cuff pressure of the CobraPLA could reduce the incidence of postoperative sore throat (POST).

METHODS

After induction of general anesthesia and insertion of the CobraPLA by standardized method, the cuff pressure was set to 60 cmH(2)O (group C, n = 87) or adjusted to minimal seal-up pressure +5 cmH(2)O (group A, n = 87). The frequency and severity (0, none; 1, mild; 2, moderate; 3, severe) of throat soreness, pain, discomfort, and adverse effects were evaluated 1 and 24 h after removal of the CobraPLA.

RESULTS

Incidence of moderate POST in group C was higher than that in group A (11% vs. 2%, P = 0.021) whereas the overall POST incidence was not different between the two groups (31% vs. 20%, P = 0.092). The inflated air volume of group A was different from that of group C (41 vs. 50 ml, P = 0.009).

CONCLUSIONS

Adjustment of cuff pressure reduces the incidence of moderate POST after use of the CobraPLA.

CobraPLUS and Cookgas air-Q versus Fastrach for blind endotracheal intubation: a randomised controlled trial

BACKGROUND AND OBJECTIVE

CobraPLUS and Cookgas air-Q are supraglottic airways expected to allow safe ventilation as well as reliable blind intubation. In a prospective, controlled trial, we hypothesised that quality of ventilation and success rate of blind endotracheal intubation of these new devices would be superior to the Fastrach intubating laryngeal mask airway (ILMA). When blind intubation failed the quality of fibrescope-guided intubation was investigated. To allow identification of those patients in whom blind intubation would be difficult, we investigated the predictive value of currently used predictors for ease of endotracheal intubation.

METHODS

One hundred and eighty adult patients with documented BMI, Mallampati score, Cormack-Lehane classification, interincisor gap and thyromental distance were randomised into three groups according to the device used. Ventilation conditions were rated as excellent, good or difficult. When blind intubation failed, fibrescope-guided intubation conditions were rated as well. Statistical analysis was performed by a χ-test.

RESULTS

The quality of ventilation was excellent for all devices. Three patients in the CobraPLUS group and two patients in the ILMA and the Cookgas groups needed a slight reposition. Blind intubation through the CPLA was successful in 47%, through the Cookgas in 57%, whereas the Fastrach group had a success rate of 95%. Fibreoptic intubation was possible in all but one patient. None of the registered scores and measures allowed prediction of difficult blind intubation.

CONCLUSION

All devices appeared to be safe airways. The Fastrach ILMA proved to be a reliable facilitator for blind intubation. CobraPLUS and Cookgas air-Q allowed an easy fibrescopic intubation. Failed blind intubations could not be predicted by the used parameters.

Randomised comparison of the Classic Laryngeal Mask Airway with the Cobra Perilaryngeal Airway during anaesthesia in spontaneously breathing adult patients

We tested the hypothesis that the Cobra Perilaryngeal Airway (PLA) with its high volume low-pressure cuff would provide superior airway leakage pressure compared with the Classic Laryngeal Mask Airway (LMA) in spontaneously breathing adult patients. Ninety consecutive adult patients were randomly allocated to receive one of these two supralaryngeal devices. The airway leakage pressure was higher for the PLA compared with the LMA (22 +/- 9 cmH2O vs. 18 +/- 6 cmH2O; P < 0.05). The mean airway device intracuff pressure was lower for the PLA compared to the LMA (36.1 +/- 15.2 mmHg vs. 86.3 +/- 25.3 mmHg P < 0.0001). The time required to achieve successful insertion was greater for the PLA compared with the LMA (39 +/- 21 seconds vs. 27 +/- 10 seconds; P < 0.005). The number of attempts required to achieve successful insertion and the incidence of postoperative complications were similar in both groups. The findings suggest that the PLA provides a superior airway seal at a lower intracuff pressure compared to the LMA. However the time for successful insertion may be increased.

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.

Comparison of the Laryngeal Mask (LMA™) and Laryngeal Tube (LT®) with the Perilaryngeal Airway (CobraPLA®) in Brief Paediatric Surgical Procedures

We compared the laryngeal mask airway (LMA™) and the laryngeal tube (LT®) with the perilaryngeal airway (CobraPLA®, PLA) in anaesthetised, paralysed children having brief surgical procedures.

After obtaining informed consent, 90 paediatric ASA Status 1 and 2 patients awaiting short surgical procedures were randomised to have their airways managed with an LMA, LT or PLA. Anaesthesia was induced with sevoflurane (2.5 to 4%) and muscle paralysis with mivacurium (0.2 mg/kg intravenously). The number of insertion attempts, time taken to insert the device, haemodynamic responses to insertion (mean arterial blood pressure, heart rate, pulse oximetry and end-tidal CO 2 ), clinical performance and occurrence of postoperative sore throat were recorded.

When the airway device was removed, it was examined for visible blood. Patients and parents were asked about the occurrence of sore throat, dysphonia and dysphagia 24 hours postoperatively.

Heart rate, mean arterial blood pressure, pulse oximetry and end tidal CO 2 did not differ among the groups. Insertion times for the devices were similar (LMA: 19 ± 11 seconds, LT: 21 ± 12 seconds, PLA: 18 ± 12 seconds), as were the rates of successful insertion at first attempt (LMA 66.7%; LT 70.0%; PLA 73.3%). The number and type of airway interventions to achieve an effective airway were comparable. When the airways were removed, positive blood traces were noted on 20% of the LMAs, 20% of the PLAs and 10% of the LTs.

Haemodynamic, ventilation and oxygenation variables throughout the surgery were similar with LMA, LT and PLA and there were no significant differences in insertion time or signs or symptoms of mucosal trauma when these devices were used in paralysed children.

Comparison of the CobraPLA (Cobra Perilaryngeal Airway) and the Laryngeal Mask Airway Unique in children under pressure controlled ventilation

BACKGROUND

The Laryngeal Mask Airway-Unique (LMAU) and CobraPLA (Cobra Perilaryngeal Airway) are supraglottic airway devices. There are no published studies comparing these devices in children breathing with pressure controlled ventilation (PCV).

METHODS

Eighty pediatric patients, scheduled for elective general surgery of short duration, were randomly assigned to have either a CobraPLA or a LMAU used for airway management using PCV. We compared the devices with respect to (i) ability to form an effective cuff seal, (ii) oxygenation, (iii) endtidal carbon dioxide level, (iv) time to achieve an effective airway, (v) airway interventions required for insertion, (vi) fiberoptic score, (vii) respiratory variables and (vii) adverse events.

RESULTS

Cuff seal pressure was significantly higher for CobraPLA (27.08 +/- 4.15 cmH(2)O) than for LMAU (20.91 +/- 2.47 cmH(2)O). Oxygenation was similar in both groups while the mean endtidal CO(2) in the CobraPLA group was significantly higher than in the LMAU group (36.47 +/- 1.93 mmHg vs 34.71 +/- 3.05 mmHg, P = 0.021). Time and ease of insertion were similar, with CobraPLA requiring more frequent jaw lift and LMAU requiring more frequent adjustment of the head and neck to achieve a proper position. Fiberoptic scores were excellent with both devices. Respiratory variables were similar with the exception that the plateau pressure and mean peak pressures were significantly lower with CobraPLA. There was a low rate of blood mucosal staining of the devices. No patient in either group reported a sore throat.

CONCLUSIONS

Both devices appear to be safe and effective in establishing an adequate airway in healthy children undergoing surgery of short duration with PCV.

Insertion characteristics, sealing pressure and fiberoptic positioning of CobraPLA in children

BACKGROUND

The CobraPLA(TM) is a new supraglottic airway device designed for the use in spontaneously breathing and mechanically ventilated patients. In adults it has been found as effective as the LMA, but with better sealing qualities. The aim of the present study was to evaluate fit and sealing characteristics of CobraPLA size 1.5 and 2 in mechanically ventilated children.

METHODS

Forty children, ASA I/II, aged 1-10 years, weighing 10-35 kg were scheduled for minor surgical procedures. The number of attempts for insertion and fiberoptic positioning of the CobraPLA was assessed. After muscle relaxation had been achieved, airway sealing pressure was measured by gradually increasing maximum inspiratory pressure to a maximum of 30 cm H(2)O.

RESULTS

Insertion of CobraPLA was successful at the first attempt in 90% of patients. The vocal cords were visualized in 90% of patients (grade 0: 2.5%, grade 1: 7.5%, grade 2: 30%, grade 3: 15%, grade 4: 45%). Median sealing pressure was 20.0 +/- 6.0 cm H(2)O. In 21% of patients gastric insufflation was observed at a peak inspiratory pressure of 20 cm H(2)O or below.

CONCLUSIONS

The CobraPLA was found to have easy insertion characteristics and good anatomical fitting in children between 10 and 35 kg. If positive pressure ventilation with CobraPLA size 1.5 and 2.0 is required, peak inspiratory pressure should be kept below the leak pressure and the abdomen closely monitored for signs of gastric insufflation.

A comparison of the laryngeal tube-S and Proseal laryngeal mask during outpatient surgical procedures

BACKGROUND AND OBJECTIVE

The Laryngeal Tube Sonda (LTS) and the ProSeal Laryngeal Mask Airway (PLMA) are two new devices introduced for maintaining the airway during controlled ventilation under general anaesthesia. The present investigation compared their performance in a randomized controlled study.

METHODS

One hundred ASA I-II patients, aged 18-60 yr undergoing elective minor surgery, were randomized to receive either an LTS (n = 50) or PLMA (n = 50) for airway management. After induction of general anaesthesia, the devices were inserted, its correct placement was verified and airway leak pressure was measured. Ease of insertion, quality of airway seal, fibre-optic view and postoperative pharyngeal morbidity were examined.

RESULTS

There were no differences in patient characteristics for both groups. First-time and second-time success rates were comparable for both groups (86 vs. 88% and 96 vs. 98% in LTS and PLMA groups, respectively). The airway of one patient in each group could not be managed with these devices after three attempts. Time until delivery of first tidal volume for LTS and PLMA was 24.5 +/- 6.9 and 28.8 +/- 10.3 s. Fixation and manipulation time was 54.9 +/- 15.2 and 73.2 +/- 25 s, respectively (P < 0.05). Airway seal pressure (cm H(2)O) for LTS and PLMA was 20 +/- 8.6 and 24.1 +/- 10.8, respectively (P = 0.04). Patients were questioned on a variety of postoperative pharyngeal morbidities. Only hoarseness was more frequent in the LTS group.

CONCLUSIONS

Both devices provide a secure airway, are similar in clinical utility and are easy to insert. Better airway seal was detected in the PLMA group.

Evaluation of the Cobra perilaryngeal airway (CPLA) as an airway conduit

BACKGROUND AND OBJECTIVE

The effectiveness of the Cobra perilaryngeal airway as a routine airway device and as a conduit for tracheal intubation has not been prospectively studied to date. This study aimed to evaluate the Cobra perilaryngeal airway for its potential role in an emergency airway rescue, by analysing its use as a bridge to blind or fibre-optic-guided intubation.

METHODS

In 49 patients, the procedure was carried out as follows: fibre-optic view through the Cobra perilaryngeal airway was assessed after the insertion of the Cobra perilaryngeal airway, then blind intubation through the Cobra perilaryngeal airway was attempted. After evaluating the success of blind intubation, fibre-optic-guided intubation was performed through the Cobra perilaryngeal airway. The endotracheal tube was removed after evaluating the success of fibre-optic-guided intubation, and then conventional laryngoscopy was carried out to evaluate the Cormack & Lehane grade and airway trauma.

RESULTS

In all, 95.9% (47/49) of patients had adequate ventilation using the Cobra perilaryngeal airway; the success rates for the blind and fibre-optic-guided intubation were 36.2% and 83.0%, respectively. The patients were divided into two groups according to the fibre-optic view. Group 1 included patients with an obstructed view by an anterior grill of the Cobra perilaryngeal airway head, and a view of the anterior epiglottis (downfolded epiglottis) with or without a visible larynx (16/47, 34.0%). Group 2 included the remaining patients (31/47, 66.0%). The success rates of the blind and fibre-optic intubations were different between the two groups (blind intubation: 12.5% vs. 48.4%, fibre-optic intubation: 62.5% vs. 93.6%, P 0.05). 42.6% of patients had blood staining after removing the device and complications such as trauma and oedema were confirmed under direct laryngoscopy.

CONCLUSION

This study suggests that the Cobra perilaryngeal airway could be a useful airway device as a vehicle for fibre-optic-guided intubation; however, it needs caution against airway trauma.

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.

A randomized prospective study comparing the Cobra Perilaryngeal Airway and Laryngeal Mask Airway-Classic during controlled ventilation for gynecological laparoscopy

BACKGROUND

An increasing number of noninvasive, supraglottic airway devices are currently available. In this randomized single-blind study, we compared the Cobra Perilaryngeal Airway (CobraPLA) to the [Laryngeal Mask Airway (LMA)-Classic] during gynecological laparoscopy.

METHODS

Forty patients received either an LMA-Classic or a CobraPLA. Insertion, ventilation and removal characteristics were noted, as well as any throat morbidity.

RESULTS

Devices were similar for insertion characteristics, adverse events, and throat morbidity. Before pneumoperitoneum, peak airway pressures were 20.3 +/- 4.9 cm H2O in the LMA-Classic group versus 25.5 +/- 7.9 cm H2O in the CobraPLA group, P = 0.01. This difference was maintained during pneumoperitoneum; LMA-Classic (22.8 +/- 6.1 cm H2O) and CobraPLA (28.1 +/- 8.5 cm H2O), P = 0.04. Macroscopic blood occurred only on the CobraPLA, seen on 40% of the devices after removal, P = 0.001.

CONCLUSION

During gynecological laparoscopy, the CobraPLA provides similar insertion characteristics, but higher airway sealing pressures than the LMA-Classic. The usefulness of this finding requires further investigation.