Clinical evaluation of the use of laryngeal tube versus laryngeal mask airway for out-of-hospital cardiac arrest by paramedics in Singapore

INTRODUCTION@#It remains unclear which advanced airway device has better placement success and fewer adverse events in out-of-hospital cardiac arrests (OHCAs). This study aimed to evaluate the efficacy of the VBM laryngeal tube (LT) against the laryngeal mask airway (LMA) in OHCAs managed by emergency ambulances in Singapore.@*METHODS@#This was a real-world, prospective, cluster-randomised crossover study. All OHCA patients above 13 years of age who were suitable for resuscitation were randomised to receive either LT or LMA. The primary outcome was placement success. Per-protocol analysis was performed, and the association between outcomes and airway device group was compared using multivariate binomial logistic regression analysis.@*RESULTS@#Of 965 patients with OHCAs from March 2016 to January 2018, 905 met the inclusion criteria, of whom 502 (55.5%) were randomised to receive LT while 403 (44.5%) were randomised to receive LMA. Only 174 patients in the LT group actually received the device owing to noncompliance. Placement success rate for LT was lower than for LMA (adjusted odds ratio [OR] 0.52, 95% confidence interval [CI] 0.31-0.90). Complications were more likely when using LT (OR 2.82,0 95% CI 1.64-4.86). Adjusted OR for prehospital return of spontaneous circulation (ROSC) was similar in both groups. A modified intention-to-treat analysis showed similar outcomes to the per-protocol analysis between the groups.@*CONCLUSION@#LT was associated with poorer placement success and higher complication rates than LMA. The likelihood of prehospital ROSC was similar between the two groups. Familiarity bias and a low compliance rate to LT were the main limitations of this study.

Protocolo de colocación de tubo laríngeo / Procedure in the placement of the laryngeal tube

Mundialmente el reconocimiento de la importancia de contar con una vía aérea permeable en una situación de emergencia o urgencia ha llegado a su punto máximo. Es por esto mismo que la búsqueda de alternativas a los métodos tradicionales para la obtención de esta misma, es un desafío para los profesionales de la salud. Se han descripto múltiples dispositivos para lograr este objetivo, dentro de los cuales se encuentra el tubo laríngeo, presentando diversas ventajas y mínimas desventajas, respaldado por distintos y variados estudios que han probado su eficiencia frente a otros dispositivos que tienen el mismo fin. El objetivo del presente trabajo es lograr la unificación del procedimiento en la colocación del tubo laríngeo por parte del personal Profesional de Enfermería[AU]

Globally, the recognition of the importance of having a permeable airway in an emergency or urgent situation has reached its peak. It is for this reason that the search for alternatives to traditional methods for obtaining it is a challenge for health professionals. Multiple devices have been described to achieve this objective, among which is the laryngeal tube, presenting various advantages and minimal disadvantages, supported by different and varied studies that have proven their efficiency against other devices that have the same purpose. The aim of the present work is to achieve the unification of the procedure in the placement of the laryngeal tube by the Professional Nursing staff[AU]

Globalmente, o reconhecimento da importância de ter uma via aérea permeável em uma situação de emergência ou urgência atingiu seu auge. É por isso que a busca por alternativas aos métodos tradicionais de obtenção é um desafio para os profissionais de saúde. Vários dispositivos têm sido descritos para atingir esse objetivo, entre os quais está o tubo laríngeo, apresentando diversas vantagens e desvantagens mínimas, amparados por diversos e variados estudos que comprovaram sua eficácia contra outros dispositivos com a mesma finalidade. O objetivo do presente trabalho é alcançar a unificação do procedimento na colocação da sonda laríngea pela equipe de profissionais de enfermagem[AU]

Laryngeal tube suction for airway management during in-hospital emergencies

OBJECTIVE: The role of supraglottic airway devices in emergency airway management is highlighted in international airway management guidelines. We evaluated the application of the new generation laryngeal tube suction (LTS-II/LTS-D) in the management of in-hospital unexpected difficult airway and cardiopulmonary resuscitation. METHODS: During a seven-year period, patients treated with a laryngeal tube who received routine anesthesia and had an unexpected difficult airway (Cormack Lehane Grade 3-4), who underwent cardiopulmonary resuscitation, or who underwent cardiopulmonary resuscitation outside the operating room and had a difficult airway were evaluated. Successful placement of the LTS II/LTS-D, sufficient ventilation, time to placement, number of placement attempts, stomach content, peripheral oxygen saturation/end-tidal carbon dioxide development (SpO2/etCO2) over 5 minutes, subjective overall assessment and complications were recorded. RESULTS: In total, 106 adult patients were treated using an LTS-II/LTS-D. The main indication for placement was a difficult airway (75%, n=80), followed by cardiopulmonary resuscitation (25%, n=26) or an overlap between both (18%, n=19). In 94% of patients (n=100), users placed the laryngeal tube during the first attempt. In 93% of patients (n=98), the tube was placed within 30 seconds. A significant increase in SpO2 from 97% (0-100) to 99% (5-100) was observed in the whole population and in cardiopulmonary resuscitation patients. The average initial etCO2 of 39.5 mmHg (0-100 mmHg) decreased significantly to an average of 38.4 mmHg (10-62 mmHg) after 5 minutes. A comparison of cardiopulmonary resuscitation patients with non-cardiopulmonary resuscitation patients regarding gastric contents showed no significant difference. CONCLUSIONS: LTS-D/LTS-II use for in-hospital unexpected difficult airway management provides a secure method for primary airway management until other options such as video laryngoscopy or fiber optic intubation become available.

Experience of Laryngeal Tube Insertion in a Patient of Expected Difficult Intubation : A case report / 대한마취과학회지

Airway management is important during general anesthesia. Difficulty with a direct laryngoscopy can be routinely successfully managed using a laryngeal mask airway. However, a laryngeal mask airway may not be suitable for the patients having a small oral cavity volume or narrow interincisor distance. A 19-year-old man, scheduled for right clavicular fracture had no specific underlying medical problems. However, he had difficultly opening his mouth, and was Mallampati class IV. Also, he had difficultly in extending his neck. Airway management was successfully performed using a laryngeal tube instead of a laryngeal mask airway. The patient was successfully managed, without complications, until the end of the surgery.

The Effect of Cuff Pressure of Laryngeal Tube on Postoperative Sore Throat after General Anesthesia Using N2O / 대한마취과학회지

BACKGROUND: The cuff pressure (CP) of the laryngeal tube airway (LTA) increases during general anesthesia using nitrous oxide. However, there have been few studies on the relationship between CP and postoperative sore throat (POST). This study evaluated the efficacy of the CP on a POST on the recovery time and postoperative day. METHODS: Forty patients were divided into two groups, group M (n = 20) and group I (n = 20). In all patients, the CP was set to 65 cmH2O at the induction of anesthesia. In group M, the CP was maintained at 60-70 cmH2O during general anesthesia using N2O. However, in group I, the CP was allowed to increase. The CP was measured every 10 minutes during surgery in the two groups. The frequency and intensity (numerical rating scale of 0-100, NRS-101) of the sore throat was measured at recovery room (RR) and on postoperative day 1 (POD1). RESULTS: There was a significant increase in the CP in group I during general anesthesia and the CP was higher in group I than in group M (P < 0.05). The frequency of POST was higher in group I at RR (10% vs 70%) and POD1 (0% vs 35%) than in group M. In addition, the NRS-101 was higher in group I at RR and POD1 than in group M (P < 0.05). CONCLUSIONS: The CP of the LTA needs to be monitored and controlled during surgery in order to reduce POST.

Comparison of Laryngeal Tube Insertion Condition according to Effect-Site Concentration during Target-Controlled Infusion (TCI) of Propofol / 대한마취과학회지

BACKGROUND: The aim of the study was to compare the laryngeal tube (LT) insertion conditions at 3.0 and 3.5microgram/ml effect site concentrations (ECs) during anesthesia induction using the target-controlled infusion (TCI) of propofol. METHODS: The forty patients were randomly divided into two groups. The patients received TCI of propofol with a 6.0 microgram/ml target plasma concentration (Cpt) and then an LT was inserted without the aid of a muscle relaxant when the predicted EC reached 3.0microgram/ml (group 1) or 3.5microgram/ml (group 2). The conditions of LT insertion, i.e., mouth opening, gagging, coughing, head or limb movement, laryngospasm, and overall ease, and hemodynamic responses were evaluated 3 min after midazolam injection, at loss of consciousness and eyelash reflex, and immediately before, immediately after, 1 min after, and 3 min after LT insertion. We also compared times required to insert LTs, cuff volumes, and incidences of blood staining and of postoperative sore throat. RESULTS: The conditions of LT insertion, except laryngospasm and overall ease, were not significantly different in the two groups. The incidence of laryngospasm in group 1 (25%) was significantly higher than in group 2 (0%) and group 2 was better than group 1 in terms of overall ease of insertion (P<0.05). No significant differences were observed between the two groups in terms of hemodynamic responses. Minimum cuff volume to 60 cmH2O was 64.0 +/- 8.3 ml in Group 1 and 63.9 +/- 6.5 ml in Group 2, and time required for LT insertion was 21.0 +/- 11.0 sec in Group 1 and 24.7 +/- 16.6 sec in Group 2. Postoperative sore throat and blood stain incidences were not significantly different in the two groups. CONCLUSIONS: After induction with 6microgram/ml of Cpt using propofol TCI for LT insertion, LT insertion at 3.5microgram/ml of EC provided a lower incidence of laryngospasm and better overall ease than insertion at 3.0microgram/ml of EC.

Clinical Effectiveness of Laryngeal Mask Airway ProSeal(TM), Laryngeal Tube and PAxpressTM as a Supraglottic Airway / 대한마취과학회지

BACKGROUND: Supraglottic airway devices can be used to maintain stable hemodynamics during intubation, to secure a difficult airway and to administer muscle relaxants at reduced levels for brief operation. We investigated the insertion success rates, hemodynamic stabilities after insertion, intraoperative ventilatory parameters, and postoperative laryngopharyngeal discomforts of three supraglottic airway devices: the ProSealTM laryngeal mask airway (PLMA), the laryngeal tube (LT), and the PAxpressTM (PAX). METHODS: After induction with thiopental 5 mg/kg with fentanyl 1microgram/kg and rocuronuim 0.6 mg/kg as muscle relaxants, manual control ventilation was done with N2O : O2 (1 : 1) and sevoflurane 5-6 vol% for 2 minutes. The supraglottic airway devices were inserted into 94 adult ASA physical status I and II patients. Unblinded observers collected the intraoperative data, and blinded observers collected the postoperative data. RESULTS: The success rates of first-attempts were similar (PLMA: 96.9%, LT: 93.1%, PAX: 96.8%). The time to achieve effective ventilation was shorten for PLMA. Peak inspiratory pressure (PIP) was significant higher for PAX than PLMA. Cuff pressure significantly increased in LT at 60 and 90 minutes after insertion. LT provided the tightest seal for positive ventilation. The incidence of blood-tinged and sore throat was highest for PAX. CONCLUSIONS: These three supraglottic airway devices can be used successfully and effectively without gastric insufflation. We suspected that the incidences of airway complications were proportional to PIP and cuff pressure and that they are dependent upon insertion skill.

The Comparison of Laryngeal Mask Airway and Laryngeal Tube in Spontaneous Breathing Anesthetized Pediatric Patients / 대한마취과학회지

BACKGROUND: During general anesthesia, the most commonly used way of keeping airway patency is endotracheal intubation. However, for relatively short and simple surgery, less invasive method using laryngeal tube (LT) or laryngeal mask airway (LMA) is generally accepted and the comparative study between the two apparatus is now being actively done. In this study, we evaluated the usefulness of two apparatus from pediatric patients. METHODS: We select 58 children from one to ten years old who are to be given short operation and then anesthetize 30 children by using LT and 28 children by LMA. The size of LT and LMA is chosen by body weight according to the manufacturer's recommendation. We evaluated the seal pressure of LT and LMA, ventilatory efficiency, attempt number, facility of insertion, proper positioning confirmed by fiberoptic bronchoscopy, and complications. RESULTS: There was no statistically significant difference in the attempt number and facility of insertion between the two groups. LT and LMA were both properly positioned and the ventilation efficiency was not different from the two groups. The LT group shows higher seal pressure than the LMA group and there is no correlation between sealing pressure and ventilation efficiency. There is close correlation between bronchoscopic grade and ventilatory efficiency. complications are not different between two groups. CONCLUSIONS: Both LT and LMA are useful for simple surgery of children and LT has higher sealing pressure.

A Comparison of the Laryngeal Tube, Laryngeal Mask Airway ClassicTM and Laryngeal Mask Airway ProsealTM during General Anesthesia / 대한마취과학회지

BACKGROUND: The laryngeal tube is a variant of the esophageal obturator airway. We compared laryngeal tube (LT), laryngeal mask airway classicTM (LMA) and laryngeal mask airway ProsealTM (PLMA) as a airway management device during general anesthesia. METHODS: Forty-five fasted healthy adult patients were enrolled in this study into one of three groups in a randomized, single-blinded protocol. Group 1 was to receive LT for airway management, LMA for Group 2, and PLMA for Group 3. General anesthesia was induced identically in three groups with thiopental sodium 5 mg/kg followed rocuronium 0.6 mg/kg. 90 seconds later, LT, LMA or PLMA was placed for airway management. Blood pressure and heart rate were measured immediately pre-induction control value, post-insertion of device 0 min, 1 min, 3 min and 5 min. We also compared times of insertion, the amounts of secretion, blood stain, and postoperative sore throat. RESULTS: There was no significant change of SBP, DBP and HR within three groups. All the groups showed stable hemodynamic results. The success rate on the first attempt was 93.6% (14/15, Group 1), 93.6% (14/15, Group 2) and 86.6% (13/15, Group 3). Minimum cuff volume to prevent gas leakage was 69.9+/-0.5 ml (Group 1), 11.1+/-4.3 ml (Group 2) and 11.9+/-3.2 ml (Group 3). The corresponding cuff pressure was 61.6+/-22.0 cmH2O (Group 1), 4.8+/-0.9 cmH2O (Group 2) and 4.6+/-1.5 cmH2O (Group 3). Moderate, severe sore throat was 20% (3/15, Group 1), 6.6% (1/15, Group 2) and 6.6% (1/15, Group 3). Moderate, profuse secretion was 40% (6/15, Group 1), 20% (3/15, Group 2) and 13.3% (2/15, Group 3). There was a 20% (3/15, Group 1) and 13.3% (2/15, Group 3) blood stain. But there was no blood stain for the Group 2. There was a 20% (3/15) gas leakage in Group 1, so we had to insert gas intermittently, but there were no gastric distension, regurgitation, aspiration, hypoxia, airway obstruction and laryngospasm in all three groups. CONCLUSIONS: All the groups revealed stable hemodynamics, no serious complications such as regurgitation, aspiration, hypoxia and airway obstruction during general anesthesia. But we did not find any evidence that LMA and PLMA have the remarkable advantages than laryngeal tube. So we suggested that laryngeal tube could be an alternative airway management device, even though further study will be needed.

Efficacy of the Laryngeal Tube in General Anesthesia / 대한마취과학회지

BACKGROUND: A prototype airway management device, a laryngeal tube, has been recently introduced in Korea. This study was designed to assess the efficacy of the laryngeal tube for airway management under general anesthesia. METHODS: We studied thirty-six ASA physical status I and II patients undergoing general anesthesia. Anesthesia was induced with sleep dose propofol 2.0 mg/kg i.v., supplemented with fentanyl 1 microgram/kg, and maintained with 50% nitrous oxide and propofol. After inserting the laryngeal tube, its cuff was inflated using a balloon cuff gauge until the intracuff pressure reached approximately 65 cmH2O. Adequacy of ventilation was assessed by observing the end tidal carbon dioxide wave form, chest wall movement and by stethoscope auscultation. Oropharyngeal leak pressure was also measured. Changes in heart rate, blood pressure, end-tidal carbon dioxide, airway pressure and oxygen saturation before induction, before insertion, 2, 5 and 10 minutes after insertion and 5 minutes after incision were recorded. RESULTS: The first time success rate at achieving an effective airway was 30 in 36 (83%). The mean leak pressure was 22.9+/-4.6 mmHg. Heart rate, blood pressure, oxygen saturation, end-tidal carbon dioxide and airway pressure values remained stable during laryngeal tube insertion and during the surgical procedure. CONCLUSIONS: We conclude that the laryngeal tube is easy to place, allows adequate ventilation and has a lower incidence of complications. It may offer an alternative device for the oxygenation of non-intubated patients undergoing general anesthesia.