Laryngeal Mask Company Research Articles

Unusual pericuff leak around proseal-laryngeal mask airway corrected by clamping gastric drain port: A case report

ProSealTM-Laryngeal Mask Airway (PLMA) (Laryngeal Mask Company, Henley-on Thames, UK) is commonly used for securing the airway with an added advantage over classic LMA as its gastric drain tube allows the insertion of Ryle’s tube and suctioning of gastric contents. The ProSeal LMA is designed in such a way that it allows controlled mechanical ventilation. During controlled mechanical ventilation, air leaks can occur because of positive airway pressures. Air leaks from the gastric drain port are almost always due to the malposition of PLMA. Here, we report a case of air leak from gastric drain port despite correctly placed PLMA and its successful management without removing the device.

Comparison of 2 cuff inflation methods of laryngeal mask airway Classic for safe use without cuff manometer in adults

PurposeThis single-center, prospective, randomized, double-blind, 2-arm, parallel group comparison trial was performed to establish whether the adult-sized laryngeal mask airway (LMA) Classic (The Laryngeal Mask Company Ltd, Henley-on-Thames, UK) could be used safely without any consideration of cuff hyperinflation when a cuff of the LMA Classic was inflated using half the maximum inflation volume or the resting volume before insertion of device. Basic proceduresEighty patients aged 20 to 70 years scheduled for general anesthesia using the LMA Classic were included. Before insertion, the cuff was partially filled with half the maximum inflation volume in the half volume group or the resting volume created by opening the pilot balloon valve to equalize with atmospheric pressure in the resting volume group. Several parameters regarding insertion, intracuff pressure, airway leak pressure, and leakage volume/fraction were collected after LMA insertion. Major findingsThe LMA Classic with a partially inflated cuff was successfully inserted in all enrolled patients. Both groups had the same success rate of 95% at the first insertion attempt. The half volume group had a lower mean intracuff pressure compared with the resting volume group (54.5 ± 16.1 cm H2O vs 61.8 ± 16.1 cm H2O; P = .047). There was no difference in airway leak pressure or leakage volume/fraction between the 2 groups under mechanical ventilation. ConclusionsThe partially inflated cuff method using half the maximum recommended inflation volume or the resting volume is feasible with the adult-sized LMA Classic, resulting in a high success rate of insertion and adequate range of intracuff pressures.

Prolonged use of the LMA Supreme™

To the Editor, The LMA Supreme (The Laryngeal Mask Company Limited, Le Rocher, Victoria, Mahe, Seychelles) is a disposable extraglottic laryngeal mask airway that features high airway sealing pressures and a channel for gastric decompression. We report the use of an LMA Supreme in an unexpected prolonged surgery. The patient gave written consent for the publication of this case report. A 74-yr-old male (weight 68 kg, height 168 cm) with a history of allergic rhinitis was admitted for re-intervention of a mixed tumour of the parotid gland. The physical examination and laboratory tests were normal, and no criteria were found to predict difficult airway management. Expected duration of surgery was two hours. The neurophysiologist requested avoidance of neuromuscular blockade and halogenated anesthetics to allow monitoring of facial nerve branches. Standard hemodynamic variables, urine output, and bispectral index (BIS) were monitored. Anesthesia was induced with propofol 2 mg kg and maintained with a continuous infusion of propofol (4-6 mg kg hr) and remifentanil (0.2-0.4 lg kg min), adjusted for a BIS target value 60. Nitrous oxide was not used. A size-4 LMA Supreme was inserted and the cuff was inflated with 20 mL of air. Volume-controlled ventilation was initiated with the following parameters: tidal volume 6 mL kg; inspiratory:expiratory ratio 1:2; and respiratory frequency 12 breaths min. Peak inspiratory pressure was 16 cm H2O during the procedure and the capnographic wave was normal. Once the airway sealing was assessed, we placed a 16G orogastric drain tube, decompressed the patient’s stomach, and connected the drain tube to a drainage bag on the floor. Due to dissection difficulties, the surgery lasted for seven hours and 20 min, and we left the LMA Supreme in place during all this time. There was no air leakage throughout the surgery, and the drainage bag collected only a few millilitres of bilious fluid. We administered dexamethasone 4 mg, acetaminophen 1 g, and dexketoprofen 50 mg iv before the end of surgery. We removed the LMA Supreme with the patient awake and breathing spontaneously. History and physical examination of the patient in the recovery room immediately after surgery and before discharge ruled out any side effects relating to prolonged use of the LMA Supreme. Most reported problems associated with the laryngeal mask airway (LMA) are related to the misuse of the device. Complications, such as mucosal ischemic injury, gastric insufflation, regurgitation, and aspiration, appear to be time-dependent. As a result, LMAs have been used chiefly for short surgical procedures. The risk of mucosal injury increases with cuff volume due to increased mucosal pressure. A well-placed LMA Supreme provides adequate airway sealing with minimal intracuff volume, which is important for prolonged use. A 20-mL volume of air for a size-4 LMA Classic does not produce elevated pressure on the pharyngeal mucosa, but we have a lack of corresponding data for the LMA Supreme. As we had no possibility of measuring intracuff pressure, we used 20 mL of air with good sealing pressure ([ 25 cm H2O). Although data are lacking on mucosal pressure applied by the LMA Supreme, it appears that a 20-mL volume is safe for prolonged use without nitrous oxide. Incorporating a drain tube with the LMA Supreme minimizes the likelihood of gastric insufflation and allows a route to vent regurgitated gastric contents. Publications investigating a safe time limit M. Kammah, MD (&) C. Anez, MD, PhD Servicio de anestesiologia y reanimacion, Hospital Universitario Joan XXIII, Rambla President Lluis Company, Tarragona, Spain e-mail: maryemane@gmail.com

The effect of a cervical collar on the seal pressure of the LMA Supreme™: a prospective, crossover trial

For personnel inexperienced in airway management, supraglottic airway devices may be the first choice in an emergency. Changing head position is known to reduce the seal pressure of a laryngeal mask airway. The aim of this study was to investigate whether the use of a cervical collar improves the stability of airways secured with the LMA Supreme™ (The Laryngeal Mask Company Limited, Mahé, Seychelles). In this crossover trial, the primary endpoint was the difference in the seal pressure of the LMA Supreme in anaesthetised patients in maximum passive extension of the neck, with and without a cervical collar. The median (IQR [range]) seal pressure was 18 (13.8-22.1 [0-30]) cmH(2) O in maximum passive extension without a cervical collar. With a cervical collar in place, the seal pressure increased to 28 (22.8-30 [17-30]) cmH(2) O (p<0.001). In the neutral head position, the seal pressure was 22 (17.6-24.5 [12-30]) cmH(2) O without and 27 (22-30 [12-30]) cmH(2) O with a cervical collar in place (p<0.001). We found that a cervical collar stabilises the airway with an LMA Supreme in place and we recommend this combination for (pre-hospital) emergency cases.

Stylet-Assisted Tracheal Intubation Through an ILMA in a Patient with an Anterior Larynx

To the Editor Although the intubating laryngeal mask airway (ILMA) has been described for use in morbidly obese patients,1 despite its correct placement, tracheal intubation may be unsuccessful. An obese male patient (body mass index [BMI] = 34) in the intensive care unit with a right middle cerebral artery territory stroke required urgent tracheal intubation owing to poor Glasgow coma scale (E1V1M2). After sedation and paralysis, ventilation via a mask was adequate but intubation using a #4 Macintosh blade, external laryngeal manipulation, and a bougie was not possible. An ILMA (#4 LMA-Fastrach™, The Laryngeal Mask Company Limited, Le Rocher, Victoria, Mahé, Seychelles) was placed and ventilation resumed. Tracheal intubation using the flexometallic tube provided with the ILMA failed as the tube tip was repeatedly displaced into the esophagus. Repositioning of the ILMA and Chandy's maneuver part 22 were attempted but also unsuccessful. Intubation with a 7.0-mm internal diameter cuffed Portex polyvinyl chloride (PVC) endotracheal tube (ETT) (Smiths Medical, UK), together with a flexion maneuver, also did not help because of the anteriorly positioned larynx. Size 5 ILMA and Fiberoptic Bronchoscope were unavailable. Hence, using a stylet, the tip of the portex tube was bent as shown in Figure 1 and reintroduced through ILMA, and the ETT could be easily advanced off the stylet into the trachea.Figure 1: Angle of emergence formed by the tracheal tubes on emerging from the distal aperture of the intubating laryngeal mask airway (ILMA). A, LMA-Fastrach silicone wire-reinforced tube (7.5-mm internal diameter). B, Portex polyvinyl chloride tracheal tube (7.5-mm internal diameter). C, Portex polyvinyl chloride tracheal tube with stylet (PVCT; 7.5-mm internal diameter).In cases of extremely anterior larynx, accentuating the angle of emergence of the tracheal tube from the ILMA may facilitate intubation.3 This may be safely done by ensuring that the tip of the stylet remains within the ETT, about 1 to 2 cm proximal to the tip of ETT. We measured the angle of emergence (using a protractor) of Flexometallic and Portex PVC ETT through ILMA and found them to be 35° and 45°, respectively (Fig. 1A & 1B). Introducing a stylette as suggested increases the angle of emergence to 65° (Fig. 1C), which aids in placement of the tracheal tube tip through ILMA in patients with anterior larynx. Damage to the arytenoids and trachea is a potential complication of blind intubation. Difficulty in advancing the tube due to impingement upon the anterior surface of the larynx is another possibility. Using the Parker flexitip PVC tube is an option in this scenario. The centered, tapered, and flexible distal tip gently flexes when resistance is encountered, thus enabling successful introduction minimizing airway trauma.4 Patient consent statement Written permission from the patient's first degree relative was obtained because the patient passed away at home owing to unrelated causes, months after treatment, prior to this submission. The written consent statement is available from the archival author. Georgene Singh, MD Appavoo Arulvelan, MD Kadarapura N. Gopalakrishna, MD Sethuraman Manikandan, MD Vimala Smita, MD, DM Ramesh C. Rathod, MD Department of Anesthesiology Sree Chitra Tirunal Institute for Medical Sciences and Technology Thiruvananthapuram Kerala, South India [email protected]

Intubation of the morbidly obese patient: GlideScope® vs. Fastrach™

Several potential problems can arise from airway management in morbidly obese patients, including difficult mask ventilation and difficult intubation. We hypothesised that endotracheal intubation of morbidly obese patients would be more rapid using the GlideScope(®) (GS) (Verathon Inc Corporate Headquarters, Bothell, WA, USA) than with the Fastrach™ (FT) (The Laryngeal Mask Company Ltd, Le Rocher, Victoria, Mahe, Seychelles). One hundred patients who were scheduled for bariatric surgery were randomised to tracheal intubation using either a GS or an FT. The inclusion criteria were age 18-60 years and a body mass index of ≥ 35 kg/m(2) . The primary end point was intubation time, and if intubation was not achieved after two attempts, the other method was used for the third attempt. The mean intubation time was 49 s using the GS and 61 s using the FT (P = 0.86). A total of 92% and 84% of the patients were intubated on the first attempt using the GS and the FT, respectively. One tracheal intubation failed on the second attempt when the GS was used, and five failed on the second attempt when the FT was used. There were no incidents of desaturation and no differences between the groups in terms of mucosal damage or intubation difficulty. We experienced one oesophageal intubation using GS and six oesophageal intubations in five patients using FT. There was no difference between the pain scores or incidence of post-operative hoarseness associated with the two intubation techniques. No significant difference between the two methods was found. The GS and the FT may therefore be considered to be equally good when intubating morbidly obese patients.

Tongue numbness following laryngeal mask airway Supreme™ and i‐gel™ insertion: two case reports

We present two cases of transient lingual nerve injury that were associated with the use of a laryngeal mask airway Supreme™ (The Laryngeal Mask Company, Singapore) during lumbar discectomy in a 43-year-old female and i-gel™ (Intersurgical, Berkshire, UK) during ovum pick up in a 33-year-old female. They presented with numbness at the tip of their tongues and spontaneously and fully recovered 2 weeks after their operations.

Conductive warming and insulation reduces perioperative hypothermia

Abstract

Erratum to Inferior alveolar nerve injury with laryngeal mask airway: a case report

ABSTRACT: Following the publication of our article [Inferior alveolar nerve injury with laryngeal mask airway: a case report. Journal of Medical Case Reports 2011, 5:122] it was brought to our attention that we inadvertently used the registered trademark of the Laryngeal Mask Company Limited (LMA) as the abbreviation for laryngeal mask airway. A Portex(R) Soft Seal(R) Laryngeal Mask was used and not a device manufactured by the Laryngeal Mask Company.

Inexperienced nurses and doctors are equally efficient in managing the airway in a manikin model

ObjectiveThe aim of the present study was to investigate whether minimally trained medical and nursing school graduates would be equally efficient in placing a laryngeal mask airway (LMA) and in intubating the trachea with the Macintosh blade or a videolaryngoscope in a manikin model. Airway management is an essential skill for both physicians and nurses who may be confronted with a critically ill patient, because in the emergency department the airway is not exclusively managed by medical personnel. Several studies have shown that other healthcare professionals are not any less efficient in securing the airway. MethodsNinety-six graduates from medical and nursing faculties comprised our study population. After a brief educational session, participants were randomly allocated into 3 groups to secure the airway in manikins with 3 techniques: LMA (The Laryngeal Mask Company Limited, Buckinghamshire, UK) insertion and intubation with the Macintosh blade and with a videolaryngoscope (GlideScope, Verathon Inc, Bothell, WA). The number of attempts until the first successful intubation, time required for the first successful attempt, and severity of dental trauma were assessed. ResultsNo statistically significant difference was observed between physicians and nurses in the number of attempts and in the time required for the first successful attempt with any of the 3 techniques studied. From the 3 techniques studied, LMA placement was the fastest (P < .001). No significant difference was observed between physicians and nurses in the severity of dental trauma. ConclusionNurses are as efficient as physicians in managing the airway safely and adequately with the 3 different techniques in manikins.

Management of Unanticipated Difficult Airway in the Prehospital Emergency Setting

We were greatly interested in the recent article of Combes et al. 1that prospectively validated a prehospital difficult-intubation algorithm. In this clinical study, the tracheal intubation with direct laryngoscope proved impossible in 160 patients. However, of these 160 patients, 15 had a laryngeal view of the Cormack and Lehane (C&amp;L) class I or II, which is generally regarded as an easy laryngoscopy.2The ease of direct laryngoscopy is not synonymous with ease of tracheal intubation, but the laryngeal view obtained by direct laryngoscopy usually is an important determinant of successful intubation. We would like to know the detailed cause of failed intubation in these patients with an easy laryngoscopy. Moreover, the authors did not clearly describe whether their algorithm required for use of an endotracheal tube with a malleable stylet at the initial intubation attempt. In managing difficult intubation, mounting the endotracheal tube onto a stylet and angling the distal tip upward help to guide the tube tip toward the glottis and improve the success rate of tracheal intubation.3This measure is especially useful when a poor laryngeal view is obtained during direct laryngoscopy or when using a flexible endotracheal tube without a natural anterior curve. In general, when speed of tracheal intubation is important (as in a patient with a full stomach or chest compression), an endotracheal tube should always be equipped with a stylet.4In this difficult-intubation management algorithm, the authors recommended that if the tracheal intubation failed after either two attempts with a C&amp;L class less than IV or a single attempt with a C&amp;L class IV, along with optimal upper airway and head manipulations, the participants were requested to move to the next step of the algorithm, the gum elastic bougie (GEB). GEB-guided intubation was used as first choice and the intubating laryngeal mask airway (ILMA) as a backup. However, what usually determines the successful intubation with the GEB is part or complete visualization of the epiglottis with or without laryngeal structure. For an intubator who has no extensive experience in the GEB-guided intubation, if direct laryngoscopy can not expose any epiglottic structure as an objective mark (e.g. , C&amp;L class IV), blindly inserting the GEB into the trachea will be very difficult. In clinical practice, the GEB-guided intubation is really most suitable for patients with a C&amp;L class less than IV.5Thus, we consider that in their difficult-intubation management algorithm, the rescue step to use the GEB-guided intubation as first choice may be suitable only for the patients with a C&amp;L class less than IV. After a single intubation attempt failed in patients with a C&amp;L class IV, the rescue airway algorithm should move directly to the step that uses the ILMA to ventilate the patients and then to intubate the trachea, but not to the step that attempts reintubation with the GEB because it has high risks of failed intubation and increased airway trauma. For this situation, we completely agree with the editorial view of Drs. Isono and Ishikawa that maintenance of oxygenation is the final goal of airway management.6The authors did not clearly state the type of the ILMA used for this difficult-intubation management algorithm. When an ILMA is used as a rescue airway device in the prehospital setting, we recommend use of the ILMA CTrach™ (Laryngeal Mask Company Limited, San Diego, CA) with the integrated fiberoptic channels and a detachable liquid crystal display viewer, rather than the ILMA Fastrach™ (Laryngeal Mask Company Limited). It has been shown that compared with the ILMA Fastrach™, the ILMA CTrach™ can enable a higher first-attempt success rate of tracheal intubation because of the view of the glottis it provides, the way it optimizes placement of the device, and the ability to observe the process of tracheal intubation through the device.7In addition, data from the study of Nickel et al. 8suggest that the ILMA CTrach™ is a suitable device for emergency airway management in the prehospital setting because it provides ventilation and facilitates intubation with a very high success rate.*Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China. fruitxue@yahoo.com.cn

Patient with Posterior Mediastinal Mass Requiring Urgent Cardiopulmonary Bypass

T HE literature on anesthetic concerns and perioperative care of patients with mediastinal masses has focused almost exclusively on anterior mediastinal masses. Posterior mediastinal masses traditionally have been suggested to carry a low risk of anesthetic implications. We present the case of a patient with a posterior mediastinal mass who experienced hemodynamic and respiratory decompensation upon induction of general anesthesia and required urgent transition to cardiopulmonary bypass (CPB). Our case illustrates the importance of real-time imaging provided by transesophageal echocardiography (TEE) in explaining the etiology of intractable hemodynamic instability and a new finding of significant pericardial and left pleural effusion not seen on preoperative imaging. TEE made clear the urgent need to initiate CPB because it revealed a near total compression of the left atrium, which was obstructing delivery of volume to the left ventricle. In addition, this case demonstrates the inadequacy of “stand-by” CPB and the need for every institution to establish an interdisciplinary team to develop, before surgery, a formal plan for the perioperative care of patients with mediastinal masses.

Failure to Ventilate with the Dräger Apollo® Anesthesia Workstation

Failure to Ventilate with the Dräger Apollo® Anesthesia Workstation

Case Scenario: Perioperative Airway Management of a Patient with Tracheal Stenosis

TRACHEAL stenosis is a rare but a life-threatening condition and is caused by congenital problems, postintubation injury, trauma, tracheal tumor, and compression of the trachea by tumor. Although accurate prevalence of this condition is unknown, an incidence of 4.9 cases per million per year is estimated for postintubation tracheal stenosis. A stenosis commonly occurs at the cuff of the tube (intrathoracic trachea) or at the level of the tracheostomy stoma (extrathoracic trachea). Anesthesia of a patient with tracheal stenosis is challenging for anesthesiologists. Depending on the severity and location of the stenosis and the type of surgical procedure, there may be a variety of choices for perioperative airway management such as a facemask, laryngeal mask airway, an tracheal intubation tube, cardiopulmonary bypass, and extracorporeal membrane oxygenation. The American Society of Anesthesiologists practice guidelines for management of the difficult airway primarily focus airway problems caused at the extrathoracic airway and may not be helpful, particularly for managing patients with intrathoracic tracheal stenosis. In this case scenario, we present a patient with severe intrathoracic tracheal stenosis, who required surgery for a lumbar fracture in the prone position. Various airway management strategies and the actual management used are discussed.

Comparison of bougie-guided insertion of Prosealtmlaryngeal mask airway with digital technique in adults

The Proseal™ laryngeal mask airway (PLMA™, Laryngeal Mask Company, UK) was designed to improve ventilatory characteristics and offer protection against regurgitation and gastric insufflation. The PLMA is a modified laryngeal mask airway with large ventral cuff, dorsal cuff and a drain tube. These modifications improve seal around glottis and enable better ventilatory characteristics. The drain tube prevents gastric distension and offers protection against aspiration. There were occasional problems, like failed insertion and inadequate ventilation, in placing PLMA™ using the classical digital technique. To overcome these problems, newer placement techniques like thumb insertion technique, introducer tool placement and gum elastic bougie (GEB)-aided placement were devised. We compared classical digital placement of PLMA™ with gum elastic bougie-aided technique in 60 anaesthetised adult patients (with 30 patients in each group) with respect to number of attempts to successful placement, effective airway time, airway trauma during insertion, postoperative airway morbidity and haemodynamic response to insertion. The number of attempts to successful placement, airway trauma during insertion and haemodynamic response to insertion were comparable among the two groups, while effective airway time and oropharyngeal leak pressure were significantly higher in bougie- guided insertion of PLMA. Postoperatively, sore throat was more frequent with digital technique while dysphagia was more frequent with bougie guided technique. Hence gum elastic bougie guided, laryngoscope aided insertion of PLMA is an excellent alternate to classical digital technique.

Crossover Comparison of the Laryngeal Mask Supreme™ and the i-gel™ in Simulated Difficult Airway Scenario in Anesthetized Patients

The single-use supraglottic airway devices LMA-Supreme (LMA-S; Laryngeal Mask Company, Henley-on-Thames, United Kingdom) and i-gel (Intersurgical Ltd, Wokingham, Berkshire, United Kingdom) have a second tube for gastric tube insertion. Only the LMA-S has an inflatable cuff. They have the same clinical indications and might be useful for difficult airway management. This prospective, crossover, randomized controlled trial was performed in a simulated difficult airway scenario using an extrication collar limiting mouth opening and neck movement. Sixty patients were included. Both devices were placed in random order in each patient. Primary outcome was overall success rate. Other measurements were time to successful ventilation, airway leak pressure, fiberoptic glottic view, and adverse events. Success rate for the LMA-S was 95% versus 93% for the i-gel (P = 1.000). LMA-S needed shorter insertion time (34 +/- 12 s vs. 42 +/- 23 s, P = 0.024). Tidal volumes and airway leak pressure were similar (LMA-S 26 +/- 8 cm H20; i-gel 27 +/- 9 cm H20; P = 0.441). Fiberoptic view through the i-gel showed less epiglottic downfolding. Overall agreement in insertion outcome was 54 (successes) and 1 (failure) or 55 (92%) of 60 patients. The difference in success rate was 1.7% (95% CI -11.3% to 7.6%). Both airway devices had similar insertion success and clinical performance in the simulated difficult airway situation. The authors found less epiglottic downfolding and better fiberoptic view but longer insertion time with the i-gel. Our study shows that both devices are feasible for emergency airway management in patients with reduced neck movement and limited mouth opening.

LMA-ProSeal™ for Elective Postoperative Care on the Intensive Care Unit

Background Compared to an endotracheal tube, laryngeal mask airways are known to cause less hemodynamic alteration during the extubation phase of routine perioperative airway management. This study aims to examine the hypothesis that the LMA-ProSeal (PLMA, The Laryngeal Mask Company Limited, St. Helier, Jersey, Channel Islands) is an adequate tool for elective postoperative care in the intensive care unit (ICU) and potentially associated with less hemodynamic alteration during extubation in the ICU environment compared to an endotracheal tube. Methods Forty-eight patients were enrolled for this prospective randomized, controlled trial and were allocated to either control (ICU-T) or study group (ICU-P). In the ICU-P group, the endotracheal tube was replaced by a PLMA at the end of surgery. Results Forty-patients completed the study. Cardiovascular parameters increased significantly less in the ICU-P group: systolic blood pressure increased by 18.10 +/- 5.57 mmHg versus 34.65 +/- 5.63 mmHg (P &amp;lt; 0.05), mean arterial blood pressure increased by 11.23 +/- 3.25 mmHg versus 22.65 +/- 3.36 mmHg (P &amp;lt; 0.05), and heart rate increased by 9.3 +/- 2.9 versus 12.9 +/- 2.2 min (P &amp;lt; 0.05). Ventilation via the PLMA during transfer from the operation room to the ICU as well as during ICU stay was successful and without any adverse events. Conclusions Removal of the PLMA after recovery from anesthesia was associated with less cardiovascular change compared to the endotracheal tube. Ventilation was possible without reported adverse events during the entire trial. Elective endotracheal tube replacement by the PLMA may be a useful procedure in selected patients.

Use of a ProSeal™ laryngeal mask airway for eight hours of unplanned abdominal surgery

To the Editor, The ProSeal laryngeal mask airway (PLMA) is used commonly for relatively short procedures, but there is no recognized safe maximum time limit. We report a case in which a PLMA was left in place for more than 8 h. A 40-year-old otherwise healthy man with a body mass index of 29 kg m presented for elective laparoscopic cholecystectomy. He had no reflux symptoms and airway examination was normal. General anesthesia was induced with propofol and remifentanil infusions, and rocuronium was used for muscle relaxation. A size 5 PLMA (Laryngeal Mask Company, Henley-on-Thames, UK) was inserted uneventfully and correct positioning was confirmed. Cuff pressure was maintained at 60 cmH2O by continuous monitoring. Oropharyngeal leak pressure was 35 cmH2O. A gastric tube was passed via the PLMA drain tube. Controlled ventilation using oxygen and air was initiated (tidal volume, 8 mL kg; respiratory rate, 12 breaths min). After 65 min of difficult laparoscopic surgery, a subcostal laparotomy was performed for aberrant biliary tract dissection, reconstruction, and anastomosis. The open procedure lasted 6 h 40 min. Anesthesia and ventilation were uneventful throughout with stable oxygenation, square-wave capnography, and unchanging spirometry. The surgeons saw no gastric inflation. Peak airway pressures were 26 cmH2O during laparoscopy and 18 cmH2O during open surgery. Surgical conditions were described as ‘‘very good.’’ After leaving the PLMA in place for a total of 8 h 40 min, neuromuscular blockade was antagonized, spontaneous breathing was re-established, and emergence was smooth and uneventful. The patient recovered well with no oropharyngeal or other sequelae. Several studies suggest benefits of PLMA use for short laparoscopic procedures over the Classic laryngeal mask airway (LMA-C) and perhaps over the tracheal tube (TT). When laparoscopic surgery becomes complicated, issues of the PLMA’s suitability for prolonged surgery should be balanced against the risks of changing the airway during surgery. Brimacombe and Shorney used a LMA-C for 8 h of peripheral surgery with the patient breathing spontaneously. There is scant scientific evidence that prolonged LMA use is either harmful or safe. In this case, when laparotomy became necessary, we saw no indication that the PLMA should be changed to a TT, as the ventilatory measurements were all excellent. A study in pigs indicates that PLMA use beyond 3 h may be associated with laryngopharyngeal mucosal injury and suggests an association between the degree of mucosal injury and duration of use. The relationship between cuff pressure and severity of laryngopharyngeal mucosal injury is complex, but recommendations to limit cuff pressure to 60 cmH2O are evidence-based. 5 The large PLMA cuff is associated with the lowest mucosal pressure of the LMAs. It is extremely unlikely that our case represents the longest use of a PLMA. The second concern during prolonged LMA use is the risk of aspiration. It is unknown whether this risk increases during prolonged anesthesia or whether LMA use impacts on this risk, but it seems unlikely. Notably, PLMA design and function minimizes the likelihood of regurgitation and aspiration, and extensive evidence supports this. When the surgical plan changes during airway maintenance with a PLMA, we advocate assessing the device J. Fabregat-Lopez, MD (&) B. Garcia-Rojo, MD E. Sanchez-Ferragut, MD University Hospital Rosell, Cartagena, Murcia, Spain e-mail: kinoyo@hotmail.com

The LMA CTrach ™ in Patients with Difficult Airways

THE LMA CTrach™ system (The Laryngeal Mask Company, Singapore) was developed from the LMA Fastrach™ system (The Laryngeal Mask Company) and consists of an LMA CTrach™ airway with fiberoptic channels and a detachable liquid crystal display viewer cum light source. The LMA CTrach™ enables ventilation, glottis visualization, and tracheal intubation via a laryngeal mask conduit. 1 In this report, we describe our experience with the LMA CTrach™ in 48 patients with difficult airways.

Transesophageal Echocardiography Induced Airway Obstruction in a Patient in Whom the Trachea Had Been Intubated via a LMA CTrach™

To the Editor: Transesophageal echocardiography (TEE) may be used as a monitor for detection of venous air embolism in patients in the sitting position.1 Only two reports of airway compression in adults from TEE probe exist, none in neurosurgical patients.2,3 A 56-yr-old female was undergoing excision of a meningioma involving the sagittal sinus. The trachea was intubated via an LMA CTrach™ (The Laryngeal Mask Company Ltd., Le Rocher, Mahe, Seychelles) because of an anticipated difficult airway. A TEE probe (Vivid 7, GE Healthcare, Milwaukee, USA) was inserted to monitor venous air embolism. However, anteflexion of the probe was followed by a sudden increase in airway pressure from 22 to 34 cm H2O with reduced ventilation. After ruling out other causes, including light anesthesia when the probe was manipulated causing the patient to bear down and thereby cause an increase in airway pressure, the TEE probe was returned to a neutral position promptly restoring airway pressure to normal. Insertion and manipulation of a TEE probe may cause variety of complications.4 In this case, we speculate that acute anteflexion of the probe compressed the membranous part of trachea and the tip of endotracheal tube. This was worsened by fixed head flexion and the sitting position. The tip of the tube supplied with LMA CTrach is softer than the tip of a flexometallic tube, contributing to the TEE-induced airway obstruction. Sriganesh Kamath, MD, DNB, DM Nilay Chatterjee, MD, DM Suparna Acharya, MD, DNB, DM Subrata Kumar Singha, MD, PDCC Department of Anesthesia Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum Kerala, India [email protected]