The New Perilaryngeal Airway (CobraPLA™) Is as Efficient as the Laryngeal Mask Airway (LMA™) but Provides Better Airway Sealing Pressures

Supraglottic airway devices: a powerful strategy in airway management

The escalating airway management demands of cancer patients have prompted us to continually curate airway devices, with supraglottic airway devices (SADs) playing a significant role in this regard. SADs serve as instrumental tools for maintaining an open upper airway. Since the inception of the earliest SADs in the early 1980s, an array of advanced and enhanced second-generation devices have been employed in clinical settings. These upgraded SADs integrate specific features designed to enhance positive-pressure ventilation and mitigate the risk of aspiration. Nowadays, they are extensively used in general anesthesia procedures and play a critical role in difficult airway management, pre-hospital care, and emergency medicine. In certain situations, SADs may be deemed a superior alternative to endotracheal tube (ETT) and can be employed in a broader spectrum of surgical and non-surgical cases. This review provides an overview of the current evidence, a summary of classifications, relevant application scenarios, and areas for improvement in the development or clinical application of future SADs.

Review of Commercially Available Supraglottic Airway Devices for Prehospital Combat Casualty Care

Background

Airway obstruction is the second leading cause of potentially survivable death on the battlefield. The Committee on Tactical Combat Casualty Care lists airway optimization among the top 5 battlefield research and development priorities; however, studies show that combat medics lack access to the recommended supraglottic airway (SGA) devices. SGA devices are an alternative airway management technique to endotracheal tube intubation. Reports have shown SGA devices are easier to use and take fewer attempts to provide patent airflow to the patient when compared to endotracheal tube intubation. Military settings require a higher degree of skill to perform airway management on patients due to the environment, limited availability of equipment, and potential chaos of the battlefield. Finding the optimal SGA device for the military setting is an unmet need. The International Organization for Standardization describes basic functional requirements for SGA devices, as well as patient configurations and size limitations. Beyond that, no SGA device manufacturer states that their devices are intended for military settings.

Materials and Methods

We conducted a market review of 25 SGA devices that may meet inclusion into the medics’ aid bag. The company’s official “Instructions for Use” document, Google Scholar, and FDA reports were reviewed to obtain information for each SGA device.

Results

Twenty-five commercially available SGA devices are explored from manufacturer online sources. A commercially available device list is shown later in this paper, which provides the device’s features, indications, and contraindications based on the manufacturer’s product information documentation.

Conclusions

There are a variety of devices that require further testing to determine whether they should be included in sets, kits, and outfits.

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.

Extraglottic airway devices: technology update

Extraglottic airway devices (EADs) have revolutionized the field of airway management. The invention of the laryngeal mask airway was a game changer, and since then, there have been several innovations to improve the EADs in design, functionality, safety and construction material. These have ranged from changes in the shape of the mask, number of cuffs and material used, like rubber, polyvinylchloride and latex. Phthalates, which were added to the construction material in order to increase device flexibility, were later omitted when this chemical was found to have serious adverse reproductive outcomes. The various designs brought out by numerous companies manufacturing EADs resulted in the addition of several devices to the airway market. These airway devices were put to use, many of them with inadequate or no evidence base regarding their efficacy and safety. To reduce the possibility of compromising the safety of the patient, the Difficult Airway Society (DAS) formed the Airway Device Evaluation Project Team (ADEPT) to strengthen the evidence base for airway equipment and vet the new extraglottic devices. A preuse careful analysis of the design and structure may help in better understanding of the functionality of a particular device. In the meantime, the search for the ideal EAD continues.

Comparison of the effects of various airway devices on hemodynamic response and QTc interval in rabbits under general anesthesia

In this study, we aimed to compare the effects of various airway devices on QTc interval in rabbits under general anesthesia. The subjects were randomly separated into four groups: Group ETT, Group LMA, Group PLA, Group V-gel. Baseline values and hearth rate, mean arterial pressure and ECG was obtained at the 1st, 5th and 30th minutes after administration of anesthesia and placement of airway device and, QTc interval was evaluated. Difference was observed between ET group and V-gel group in the 5th minute mean arterial pressure values (p < 0.05). It was observed that QTc intervals at the 1st and 5th minute in the ET group significantly increased when compared with the other groups (p < 0.05). Again, it was observed that QTc interval of ET group at the 15th and 30th minute was longer when compared with PLA and V-gel groups (p < 0.05). It was also observed that QTc interval of LMA Group at the 5th minute after intubation significantly increased when compared with V-gel group (p < 0.05). It was observed that HR values of ETT group at the 1st, 5th and 15th minutes after intubation increased with regards to PLA and V-gel groups (p < 0.05). It was determined that the 30th minute hearth rate of ETT group was higher when compared to V-gel group (p < 0.05).

CONCLUSION

In our study we observed that V-gel Rabbit affected both hemodynamic response and QT interval less than other airway devices.

Efficacy of the New Perilaryngeal Airway (CobraPLA™) Versus the Laryngeal Mask Airway (LMA™) to Improve Oropharyngeal Leak Pressure in Obese and Overweight Patients

BACKGROUND

This study aimed to evaluate the applicability of Cobra perilaryngeal airway (Cobra PLA™) for obese patients under general anesthesia and also to compare the results with those of classic laryngeal mask airway (LMA™).

MATERIALS AND METHODS

Seventy-three overweight and obese patients were included in this study. The patients were randomly assigned to LMA™ or Cobra PLA™ groups. Time required for intubation, successful intubation attempt, airway sealing pressure and incidence of complications including blood staining, sore throat and dysphagia were assessed and noted.

RESULTS

Thirty-six and 37 patients were randomly allocated to LMA™ and Cobra PLA™ groups, respectively. Most patients were males and had Mallampati Class II airway in both groups. The first attempt and overall insertion success for Cobra PLA™ was significantly higher compared to LMA (P<0.05). Airway insertion was more successful (P = 0.027; 94% vs. 77%) with Cobra PLA™. Insertion times were similar with Cobra PLA™ and LMA™ (Cobra PLA™, 29.94±16.35s; LMA™, 27.00±7.88s). The oropharyngeal leak pressure in the Cobra PLA™ group (24.80±0.90 H2O) was significantly higher than that in LMA™ group (19±1 H2O, p<0.001). Sore throat was more frequent in the LMA™ group although it did not reach statistical significance (Fisher's exact test, P = 0.33). Blood staining on airway tube was seen in both groups with a higher incidence in the Cobra PLA™ group (Fisher's Exact test, P = 0.02). Incidence of dysphagia was not different between the two groups.

CONCLUSION

CobraPLA™ was found to be safe with low complications. It provided better airway sealing with high rate of the first insertion success for use in obese and overweight patients. This study recommends the use of CobraPLA™ as a rescue device in emergency situations for obese and overweight patients.

Laypersons can successfully place supraglottic airways with 3 minutes of training. A comparison of four different devices in the manikin

INTRODUCTION

Supraglottic airway devices have frequently been shown to facilitate airway management and are implemented in the ILCOR resuscitation algorithm. Limited data exists concerning laypersons without any medical or paramedical background. We hypothesized that even laymen would be able to operate supraglottic airway devices after a brief training session.

METHODS

Four different supraglottic airway devices: Laryngeal Mask Classic (LMA), Laryngeal Tube (LT), Intubating Laryngeal Mask (FT) and CobraPLA (Cobra) were tested in 141 volunteers recruited in a technical university cafeteria and in a shopping mall. All volunteers received a brief standardized training session. Primary endpoint was the time required to definitive insertion. In a short questionnaire applicants were asked to assess the devices and to answer some general questions about BLS.

RESULTS

The longest time to insertion was observed for Cobra (31.9 ± 27.9 s, range: 9-120, p < 0.0001; all means ± standard deviation). There was no significant difference between the insertion times of the other three devices. Fewest insertion attempts were needed for the FT (1.07 ± 0.26), followed by the LMA (1.23 ± 0.52, p > 0.05), the LT (1.36 ± 0.61, p < 0.05) and the Cobra (1.45 ± 0.7, p < 0.0001). Ventilation was achieved on the first attempt significantly more often with the FT (p < 0.001) compared to the other devices. Nearly 90% of the participants were in favor of implementing supraglottic airway devices in first aid algorithms and classes.

CONCLUSION

Laypersons are able to operate supraglottic airway devices in manikin with minimal instruction. Ventilation was achieved with all devices tested after a reasonable time and with a high success rate of > 95%. The use of supraglottic airway devices in first aid and BLS algorithms should be considered.

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.

Exposure to anaesthetic trace gases during general anaesthesia: CobraPLA vs. LMA classic

BACKGROUND

To prospectively investigate the performance, sealing capacity and operating room (OR) staff exposure to waste anaesthetic gases during the use of the Cobra perilaryngeal airway (CobraPLA) compared with the laryngeal mask airway classic (LMA).

METHODS

Sixty patients were randomly assigned to the CobraPLA or the LMA group. Insertion time, number of insertion attempts and airway leak pressures were assessed after induction of anaesthesia. Occupational exposure to nitrous oxide (N(2)O) and Sevoflurane (SEV) was measured at the anaesthetists' breathing zone and the patients' mouth using a photoacoustic infrared spectrometer.

RESULTS

N(2)O waste gas concentrations differed significantly in the anaesthetist's breathing zone (11.7+/-7.2 p.p.m. in CobraPLA vs. 4.1+/-4.3 p.p.m. in LMA, P=0.03), whereas no difference could be shown in SEV concentrations. Correct CobraPLA positioning was possible in 28 out of 30 patients (more than one attempt necessary in five patients). Correct positioning of the LMA classic was possible in all 30 patients (more than one attempt in three patients). Peak airway pressure was higher in the CobraPLA group (16+/-3 vs. 14+/-2 cmH(2)O, P=0.01). The average leak pressure of the CobraPLA was 24+/-4 cmH(2)O, compared with 20+/-4 cmH(2)O of the LMA classic (P<0.001; all values means+/-SD).

CONCLUSION

Despite higher airway seal pressures, the CobraPLA caused higher intraoperative N(2)O trace concentrations in the anaesthetists' breathing zone.

Comparison of the Intersurgical Solus laryngeal mask airway and the i-gel supralaryngeal device

Summary We compared the performance of the Intersurgical Solus laryngeal mask airway (LMA) with that of the i-gel in 120 patients of ASA physical status during general anaesthesia with respect to oropharyngeal leak pressure, peak airway pressure, airway manipulation, insertion time, fibreoptic view, ventilatory parameters, and peri-operative complications. After receiving a standardised induction of anaesthesia, either a Solus LMA (60 patients) or an i-gel (60 patients) was inserted. One hundred and fifteen patients completed the study. The leak pressure was significantly higher in the LMA group than the i-gel group (mean (SD) 22.7 (7.7) cmH(2)O vs 19.3 (7.1) cmH(2)O; p = 0.02). A better fibreoptic view of the larynx was obtained in patients in the LMA group (p = 0.02) compared to those in the i-gel group and less airway manipulation was required in the LMA group (p < 0.01). Both devices have good performance with very low peri-operative complications. However, the Solus LMA provides a better oropharyngeal seal, provides a better fibreoptic view, and requires less manipulation to secure the airway than the i-gel.

A Randomised, Single-blind, Controlled Trial of Silicone Disposable Laryngeal Masks during Anaesthesia in Spontaneously Breathing Adult Patients

We hypothesised that two new silicone disposable laryngeal mask airways, Meditech Systems Limited (MSL) and ProAct (PA), would perform similarly to the Classic™ Laryngeal Mask Airway (cLMA) in spontaneously breathing adult patients. One hundred and twenty consecutive adult patients were prospectively enrolled and randomly allocated to one of three groups (PA, MSL, cLMA). All patients received a standardised anaesthetic and insertion technique. The overall success rates were 97.5% for all three masks, with one failure of laryngeal mask airway insertion in each group. There was no statistical difference in airway sealing pressures between the PA laryngeal mask airway (17.9±5.9 cmH2O), MSL laryngeal mask airway (18.5±6.9 cmH2O) and cLMA (17.6±5.6 cmH2O) (P=0.816). There was no statistical difference in insertion times, ease of insertion, cuff pressure and cuff volumes. The MSL and PA disposable laryngeal mask airways provided comparable airway sealing pressures to the reusable cLMA.

The management of difficult intubation in children

This article looks at the current techniques and equipment recommended for the management of the difficult intubation scenario in pediatric practice. We discuss the general considerations including preoperative preparation, the preferred anesthetic technique and the use of both rigid laryngoscopic and fiberoptic techniques for intubation. The unanticipated scenario is also discussed.

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.

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.

Cholecystectomy of a patient with Churg-Strauss syndrome: A case report

Churg-Strauss syndrome is an allergic granulomatous angitis and the organ most commonly involved in this condition is the lung. However, this syndrome also affects the skin, cardiovascular system, kidney, peripheral nervous system and gastrointestinal system. Cardiac involvement is a rare complication but can lead to rapid-onset heart failure as the result of specific cardiomyopathy. Pericardial effusion may also occur. Acalculous cholecystitis is also a rare complication of Churg-Strauss syndrome. Here, we present a case of a patient with Churg-Strauss syndrome and severe heart failure scheduled for cholecystectomy due to acalculous cholecystitis. The patient had mild asthma symptoms, peripheral neuritis in both legs, and severe heart failure. During the preoperative period, steroids, beta2 agonists, diuretics, and antihypertensive drugs were administered. During anesthesia we attempted to prevent compromising the patient's cardiac and pulmonary functions. The surgery was completed successfully, and the patient was discharged without any complications.

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.

The Williams Airway Intubator, the Ovassapian Airway and the Berman Airway as upper airway conduits for fibreoptic bronchoscopy in patients with difficult airways

PURPOSE OF REVIEW

In this article we will summarize the available information on airways that have been suggested to provide a conduit for the bronchoscope in its passage through the upper airway during fibreoptic intubation.

RECENT FINDINGS

The Williams Airway Intubator and the Berman Oropharyngeal Airway appear to be more likely to provide a conduit for the bronchoscope than the Ovassapian Fibreoptic Intubating Airway.

SUMMARY

Though the Williams Airway Intubator and the Berman Oropharyngeal Airway are superior in this role, all the airways discussed here have major deficiencies in their function. Further research is needed in this field to meet the requirements of endoscopists in situations when it is crucial that equipment reliably fulfils its function.

Unanticipated difficult intubation

PURPOSE OF REVIEW

While there are many predictors of difficult laryngoscopic intubation, they all have a low positive predictive value. Therefore, unanticipated difficult laryngoscopic intubation will likely occur in our day-to-day practice. This review discusses recent developments in alternative airway devices and techniques in addressing these difficulties.

RECENT FINDINGS

There is emerging evidence to suggest that new supraglottic devices are useful rescue appliances, particularly for unanticipated difficulties in laryngoscopic intubation. Other new intubating devices, including the Glidescope, may also play an important role in the management of patients with unanticipated difficult or failed laryngoscopic intubation.

SUMMARY

The evidence to date does not always arm us with the ability to predict a difficult laryngoscopic intubation. Therefore, it is imperative that we equip ourselves with devices and techniques that will help us to maintain effective oxygenation and ventilation in a safe manner in the face of such failure.

Alternative airway devices for use in children requiring prehospital airway management: update and case discussion

This manuscript reviews the latest literature on alternative airways for use in children requiring prehospital airway management. Case discussions serve as a springboard for discussion of alternatives to bag-mask ventilation and endotracheal intubation for management of ventilation in infants and children in the prehospital setting. Few airway procedures have been studied with any rigor in this setting, and most of the data that are available are extrapolated from adults. Laryngeal mask airway may be the best alternative airway with the most promise to add to the armamentarium of the prehospital provider, but no controlled trial to date has been conducted.

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.

The CobraPLA during anesthesia with controlled ventilation: a clinical trial of efficacy

The CobraPLA (CPLA) is a relatively new supraglottic airway device that has not been sufficiently investigated. Here, we performed a prospective observational study to evaluate the efficacy of the CPLA during controlled ventilation. In 50 anesthetized and paralyzed patients undergoing elective surgery a CPLA was inserted and inflated to an intracuff pressure of 60 cm H2O. The success rate of insertion upon the first attempt was 82% (41/50), with a mean insertion time of 16.3 +/- 4.5 seconds. The adequacy of ventilation was assessed by observing the end tidal CO2 waveform, movement of the chest wall, peak airway pressure (13.5 cm H2O), and leak fraction (4%). We documented the airway sealing pressure (22.5 cm H2O) and noted that the the site of gas leaks at that pressure were either at the neck (52%), the abdomen (46%), or both (2%). In 44 (88%) patients, the vocal cords were visible in the fiberoptic view through the CPLA. There was no gastric insufflation during the anesthesia. Respiratory and hemodynamic parameters remained stable during CPLA insertion. Postoperative blood staining of CPLA was minimal, occurring in 22% (11/50) of patients. Mild and moderate throat soreness was reported in 44% (22/50) and 4% (2/50) of patients, respectively. Lastly, mild dysphonia was observed in 6% (3/50) of patients and mild dysphagia in 10% (5/50) of patients. Our results indicated that the CPLA is both easy to place and allows adequate ventilation during controlled ventilation.

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

BACKGROUND AND OBJECTIVE

We compared the laryngeal mask airway (LMA) and the laryngeal tube (LT) with the newly introduced perilaryngeal airway (CobraPLA, PLA) with regard to haemodynamic responses induced by airway insertion, clinical performance and occurrence of postoperative sore throat after short surgical procedures.

METHODS

After premedication, 90 ASA I-II patients awaiting short surgical procedures were randomized to receive, LMA, LT or PLA. Anaesthesia was induced with intravenous propofol (2.5 mg kg(-1)) and mivacurium (0.2 mg kg(-1)). Number of attempts, time of insertion of the device, any other unwanted effect, mean aterial pressure, heart rate, oxygen saturation and end-tidal carbon dioxide were recorded. At the end of surgery, the cuff of the device was immediately deflated and the airway device was removed. The device was examined and noted for the presence of visible blood. Patients were asked to rate their throat soreness, dysphonia and dysphagia 1 and 24 h postoperatively.

RESULTS

There were no differences in haemodynamic variables. Insertion times for the devices were similar (LMA: 20 +/- 11 s, LT: 19 +/- 14 s and PLA: 21 +/- 12 s.) The success rates at first insertion were lower in the (LMA group (57%) when compared with the PLA (97%, P < 0.05). The number and type of airway interventions for achieving an effective airway were similar. When the airways were removed 50% of the PLA devices had positive blood traces, while only 17% of the LMA and LT devices had positive blood traces (P < 0.01). Fifty percent of the patients suffered from a sore throat in the PLA group, which was significantly higher than in the LMA and LT groups (P < 0.05).

CONCLUSION

We conclude that haemodynamic, ventilation and oxygenation variables throughout the surgery were similar with, LMA, LT and PLA, but LT and PLA were easier to insert; LMA and LT caused less mucosal trauma.

A Comparison Between the PLA Cobra™ and the Laryngeal Mask Airway Unique™ During Spontaneous Ventilation: A Randomized Prospective Study

The Laryngeal Mask (LMA) Unique and the Cobra Perilaryngeal Airway (PLA) are single-use supraglottic devices. There are no published studies comparing these devices during spontaneous ventilation. We compared the LMA Unique and the Cobra PLA with respect to 1) ventilatory variables during spontaneous ventilation, 2) time to achieve an effective airway, 3) airway intervention requirements, 4) cuff seal pressures, 5) fiberoptic score, and 6) perioperative adverse events. Eighty adult ASA physical status I-II patients undergoing general anesthesia for minor routine surgery were randomly allocated to LMA Unique or PLA Cobra for airway management. No statistically significant differences were found between the devices with respect to inspiratory tidal volume, expiratory tidal volume, end-tidal CO2 concentration, respiratory rate, number and type of airway interventions required with placement, the fiberoptic score, and the incidence of perioperative adverse events. The oropharyngeal leak (seal) pressure was higher for the CobraPLA (27 +/- 7 versus 21 +/- 4 cm H2O; P < 0.001). The oxygen saturation was higher (98.1% +/- 1% versus 97.3% +/- 2%; P = 0.02) in the LMA group. Time of insertion was shorter for LMA (23.7 +/- 2 s versus 26.6 +/- 7 s; P = 0.02) and insertion difficulty was less for LMA (P = 0.03). As these differences were not judged to be clinically important, both devices appear to be effective in establishing an adequate airway in patients who are spontaneously breathing under general anesthesia.