Insertion Of ProSealTM Laryngeal Mask Airway Research Articles

Intravenous fentanyl vs. topical lignocaine for ProSeal™ laryngeal mask airway insertion with propofol induction.

Insertion of the laryngeal mask airway (LMA) without muscle relaxant requires adequate obtundation of airway reflexes, which may otherwise lead to incorrect or failed LMA placement. This study compared topical lignocaine spray vs. intravenous (IV) fentanyl, during propofol induction for insertion of the ProSeal™ LMA (PLMA). This was a prospective, randomized, double blind study, in ASA I or II patients, for elective or emergency surgery. Seventy patients (n = 70) who fulfilled the inclusion criteria were randomly assigned to receive IV fentanyl 2 mcg/kg or topical lignocaine spray 40 mg, prior to anesthesia induction with IV propofol (2–2.5 mg/kg). ProSeal™ LMA insertion condition was regarded optimal in the absence of adverse responses (gag, cough, laryngospasm and body movements), and successful LMA placement at the first attempt. Hemodynamic parameters were recorded and patients were assessed for sore throat and hoarseness post operatively. Seventy patients were analyzed. The number of patients with optimal PLMA insertion conditions were comparable between the groups (60% vs. 57%, P = 0.808). All hemodynamic parameters were comparable between groups with the exception of heart rate. Sympathetic obtundation of heart rate was greater with IV fentanyl than topical lignocaine (P < 0.05). The proportion of patients with postoperative sore throat significantly increased with the number of insertion attempts (P < 0.05). Topical lignocaine spray to the pharynx is as effective, and may be an alternative to IV fentanyl, during propofol induction for PLMA insertion. Success rate and optimal insertion condition at the first attempt, propofol requirement, blood pressure, adverse events and airway complications were comparable. Heart rate obtundation was less with topical lignocaine spray but remained within clinically acceptable values.

A novel technique for insertion of ProSeal™ laryngeal mask airway: Comparison of the stylet tool with the introducer tool in a prospective, randomised study.

Background and Aims:The ProSeal™ laryngeal mask airway (PLMA) has a soft cuff which tends to fold on itself during insertion, resulting in reduced first-attempt success rate. We compared the standard introducer technique of PLMA insertion with a novel method to prevent folding of the cuff using a Rüsch™ StyletMethods:This randomised superiority trial included 120 American Society of Anesthesiologists I–II patients between 18 and 80 years, undergoing elective surgeries under general anaesthesia using a PLMA for airway management. The PLMA was inserted using the standard introducer tool in sixty patients (Group IT), while in sixty other patients, a Rüsch™ Stylet was inserted through the drain tube up to its tip. (Group ST). The primary outcome was first-attempt success rate. Secondary outcomes included overall insertion success, number of attempts, total time to successful insertion, presence of air leaks, haemodynamic response to insertion and quality of fit assessed using Brimacombe's fibre-optic scoring. Continuous variables were compared using independent t-test or Mann–Whitney U-test and categorical variables were analysed using Chi-square test or Fisher's exact test.Results:First-attempt success rate of insertion was higher in Group ST compared to Group IT (95% vs. 82%, P = 0.04). Favourable grade of placement was better in Group ST (86.7% vs. 52.5%, P < 0.001). Overall insertion success rates and haemodynamic responses were comparable between the groups.Conclusions:PLMA insertion using the stylet tool has a higher first-attempt insertion success and superior placement compared to insertion using the conventional introducer tool.

Comparison between effects of ketamine and midazolam as co-induction agents with propofol for prosealTM laryngeal mask insertion

Introduction: Optimal conditions during supraglottic airway placement are important to prevent adverse events associated with inadequate depth of anaesthesia. This study compared propofol co-induction with ketamine or midazolam during ProSeal TM Laryngeal Mask Airway (PLMA) insertion. Materials and Methods: A total of 118 ASA I or II patients aged between 18 to 60 years requiring PLMA insertion for surgery were recruited into this prospective, randomised and double blind study. Patients were grouped into propofol (2mg/kg) co-induction with either ketamine (0.5mg/kg) or midazolam (0.03mg/kg). During PLMA insertion, the degree of mouth opening, ease of insertion, swallowing, coughing or gagging, movement and laryngospasm were scored and haemodynamic changes were recorded. Overall insertion conditions were further graded into excellent, good, poor or unacceptable. Results: The ketamine-propofol group had significantly better mouth opening ( p= 0.01) and shorter duration of apnoea ( p p Conclusion: Propofol co-induction with either ketamine or midazolam conferred comparable PLMA placement conditions.

Oral gastric tube-guided insertion of the ProSeal™ laryngeal mask is an easy and noninvasive method for less experienced users

The ProSeal™ laryngeal mask airway (PLMA) can be more difficult to insert than the classic laryngeal mask, especially in patients who have a thin palate with a steep oropharyngeal curve. Here, an oral gastric (OG) tube-guided technique is considered as a method that makes it easier to successfully insert a PLMA. Sixty patients who were scheduled to undergo general anesthesia without neuromuscular blocking were randomly allocated into two groups: 30 patients with PLMA inserted by the standard digital technique, and 30 with the PLMA inserted by an OG tube-guided technique. Most PLMA insertions were performed by less experienced users. The success rate at the first attempt, the time taken to insert the PLMA, the difficulty of the procedure, and the incidence of oropharyngeal trauma and postoperative sore throat were compared between the two groups. PLMA insertion was successfully achieved at the first attempt using the OG tube-guided technique in all 30 patients. The OG tube-guided insertion required fewer attempts (P=0.04) and led to a less difficult insertion procedure (P=0.02) than the standard digital insertion. Effective ventilation during anesthesia was achieved in all patients, with a lower mean cuff pressure in the OG tube-guided technique group (P=0.02). The frequency of blood sticking to the PLMA tube (P<0.001) and the incidence of postoperative sore throat (P=0.003) were lower in the OG tube-guided group than the standard digital technique group. OG tube-guided PLMA insertion is easier for less experienced users, trainees, and experts as well as less invasive for patients than the standard digital insertion.

Size 2.5 ProSeal(™) LMA: Is it associated with increased attempts at insertion?

Background:This randomized controlled study evaluated the success rate of insertion and the associated oropharyngeal morbidity for sizes 1.5,2 and 2.5 of ProSeal™ laryngeal mask airway (PLMA) using an alternative digital technique (D) with conventional technique using the introducer tool (IT) technique.Methods:After approval from the hospital ethics committee, 250 healthy children, 6-months to 10 years of age, undergoing elective sub-umbilical surgeries, were included and randomly allocated to D and IT groups for PLMA insertion. The standard anaesthesia protocol was followed. The primary outcomes were success rate of insertion at first attempt and blood on device on removal and the secondary outcomes were oropharyngeal leak pressure and gastric tube placement.Results:The success rate of PLMA insertion at first attempt for sizes 1.5 and 2 did not differ between the two groups. However, for size 2.5, it was significantly lower than that for the other two sizes in both groups. The incidence of blood on device was higher with the 2.5 airway in both groups, reaching statistical significance only in group D. Other parameters did not differ between the two groups.Conclusion:We conclude that size 2.5 PLMA is associated with a lower success rate of insertion and a higher incidence of blood on device using both techniques. Insertion of PLMA sizes 1.5 and 2 by an alternative digital technique is comparable to the IT technique.

Use of the Rusch Flexi-Slip Stylet for Patients With Difficult Insertion of the ProSeal™ Laryngeal Mask Airway

The ProSeal laryngeal mask airway (PLMA) offers a more effective seal and is easier for gastric tube placement to prevent aspiration than the classical laryngeal mask airway. However, it is more difficult to insert with the digital and introducer tooling techniques. The Rusch Flexi-Slip stylet (RFSS) is an accessory intubation tool that consists of a malleable coated wire and a soft atraumatic tip. It has been reported that it can facilitate easier insertion of the PLMA. Here, we report two cases in which the PLMA could not be inserted correctly on the initial attempts, and with successful placement of the PLMA after using an RFSS. In the first case, three attempts to insert the PLMA with the digital and introducer tooling techniques were unsuccessful. The second case was known to be difficult for PLMA placement because, in a previous operation, PLMA insertion for general anesthesia was unsuccessful, and in that instance required endotracheal intubation for general anesthesia. In both cases, the PLMA was successfully inserted using the RFSS technique, without difficulty. The RFSS technique offers several advantages for PLMA insertion, including the provision of effective support and a soft tip for the PLMA insertion. Other techniques to facilitate the insertion of the PLMA, including priming the drain tube with a guide are discussed. We recommend that the RFSS technique offers an effective method for cases with difficult insertion of the PLMA.

Prospective randomized comparative study of use of PLMA and ET tube for airway management in children under general anaesthesia

ProSealTM Laryngeal Mask Airway (PLMA) for children had been introduced in 2004, by Dr. Archie Brain. It has, in addition to Classic Laryngeal Mask Airway (CLMA), a drainage tube for providing a bypass channel for gastric contents to prevent regurgitation and pulmonary aspiration. A randomized prospective study was performed comprising of 60 ASA – I/II patients, between the age groups of 3 and 10 years, of either sex. All the patients were premedicated with oral Midazolam and Glycopyrollate. General anaesthesia with caudal epidural analgesia was given in all the cases. Inhalation with 8% Sevoflurane was used as a sole induction agent in all the patients. They were randomly divided into two groups. PLMA was inserted in patients of Group P and Endotracheal Tube (ETT) in patients of Group I. In all cases, after PLMA / ETT insertion; caudal epidural analgesia was given and general anaesthesia (GA) using Sevoflurane was provided for maintenance of anaesthesia. Muscle relaxant was not used in our study. We studied parameters such as number of attempts, ease of insertion and conditions during insertion, haemodynamic parameters, changes in SpO2, EtCO2, gastric insufflation, regurgitation, pulmonary aspiration, postoperative airway complications and so on. We found that insertion of PLMA as well as ETT was performed in the first attempt in all the patients. Ease of insertion and conditions during insertion were comparable in both the groups. Changes in SpO2 and EtCO2 were comparable. However, highly significant changes in haemodynamic parameters were observed in the ETT group. Complications such as sore throat (13.33% cases), coughing (40% cases), vomiting (3.33% cases) and hypoxia (3.33% cases) were observed in the ETT group. No gastric insufflation or regurgitation was noted in our study. Thus, we concluded that PLMA could be used as an effective and safe airway device in children compared to ETT undergoing general anaesthesia.

The Influence of Head Rotation on Proseal™ Laryngeal Mask Airway Sealing during Paediatric Myringotomy

Myringotomy with ventilation tube insertion in children involves turning the head from neutral to allow surgical access to the ear. In adults, rotation of the head from the mid-line generally increases the oropharyngeal leak pressure when a ProSeal laryngeal mask airway (PLMA) is used to manage the airway. There are concerns that these manoeuvres may distort or obstruct the paediatric airway. Paediatric sizes (1.5, 2.0 and 2.5) of the PLMA differ from the adult versions in that they do not have a dorsal cuff. This study examines the effect of these head position changes on the seal of the PLMA in children. Twenty-nine children (ASA 1-2, aged 0.9 to 7.5 years) scheduled for myringotomy were recruited. After PLMA insertion, oropharyngeal leak pressure and fibreoptic determined PLMA position scores were measured in the neutral position and with head rotation of 45 degrees to the left or right. Fibreoptic positioning scores were similar in all positions. Head rotation was associated with a statistically significant but modest increase in oropharyngeal leak pressure versus the neutral position (P < 0.05). After rotating the head from neutral, 38% (11 of 29) of subjects had an increase of oropharyngeal leak pressure of at least 2 cmH2O. Only 7% (2 of 29) of subjects had a decrease in oropharyngeal leak pressure with head rotation, the maximum decrease being 2 cmH2O. Airway obstruction did not occur in any of the positions. We conclude that the efficacy of the seal for the pediatric sizes PLMA is improved by head rotation for myringotomy.

Frenular Injury During Insertion of the ProSeal Laryngeal Mask Airway Using the Introducer Tool Technique

To the Editor: Microscopic mucosal injuries are common during laryngeal mask airway (LMA) insertion but macroscopic injuries are rare and few have been reported with the ProSeal™ LMA (1). We report a torn frenulum associated with ProSeal™ LMA insertion using the introducer tool technique. A 50-yr-old, 60-kg ASA physical status I male with no significant medical history was scheduled for a corneal transplant. Preoperative airway examination was normal. After induction of anesthesia, a size 5 ProSeal™ LMA was successfully inserted using the introducer tool technique. Some resistance was encountered at the back of the mouth, which was overcome by a slight increase in the force applied. The introducer blade was easily removed and the cuff was inflated with air 20 mL. The LMA was judged to be in its correct position as ventilation was easy, the bite block was between the teeth, and a 12F gastric tube was inserted at the first attempt. At the end of the procedure, the LMA was removed in the lateral position with the patient spontaneously breathing. There was a substantial amount of blood on the LMA. A torn frenulum was seen on examination (Fig. 1). The patient was re-anesthetized, tracheally intubated conventionally using a laryngoscope, and the laceration repaired by an oral surgeon (Fig. 2). Subsequent tracheal extubation and emergence were uneventful. There were no other sequelae.Figure 1.: Torn frenulum (tongue is retraced upwards, lower teeth are visible).Figure 2.: Repaired frenulum (lower teeth are visible).The injury was probably caused by accidental placement of the ProSeal™ LMA cuff between the tongue and base of the mouth, rather than the tongue and the roof of the mouth. Presumably the tongue was pushed back during insertion before slipping forward, allowing correct positioning. We strongly recommend that the LMA be placed between the tongue and the roof of the mouth under direct vision and that force is never applied during insertion. Such injuries may be less likely using the digital technique (as resistance is more easily detected) or the guided technique with a laryngoscope and gum elastic bougie (2) (as misplacement is rare). Zulkifli Mohamed Haris Wee Tze Loo Department of Anesthesia & Intensive Care Hospital Kuala Lumpur Kuala Lumpur, Malaysia Joseph Brimacombe Department of Anaesthesia and Intensive Care James Cook University Cairns Base Hospital Cairns, Australia [email protected]

A Proposed Algorithm for the Management of Airway Obstruction with the Proseal??? Laryngeal Mask Airway

To the Editor: Airway obstruction is a common problem after ProSeal™ laryngeal mask airway insertion, with a frequency of between 2% (1) and 10% (2). The management depends on the etiology, which includes reflex glottic closure (deepen anesthesia or administer a muscle relaxant), epiglottic downfolding (reinsertion with maintained laryngoscopy (3) or jaw thrust (4)), glottic/supraglottic compression (5) (jaw thrust, cuff deflation or reinsertion using a smaller size), infolding of the ventral cuff (6) (cuff deflation or reinsertion using a smaller size), and malposition (reinsertion using a guided technique) (7). Distinguishing among these etiologies are the tests for malposition and mechanical obstruction. The malposition tests are only required after nonguided insertion and comprise: (i) checking for air leaks up the drain tube during positive pressure ventilation, (ii) assessing the position of the bite block in relation to the incisors (8), and (iii) the suprasternal notch tap test (9). The mechanical obstruction tests comprise: (i) jaw thrust, which decompresses the pharynx and elevates the epiglottis, and (ii) deflating the cuff, which decompresses the glottis and reduces cuff infolding (10). The algorithm synthesizes these tests to facilitate the diagnosis and management of airway obstruction with the ProSeal™ laryngeal mask airway (Fig. 1).Figure 1.: Algorithm synthesizing tests to facilitate the diagnosis and management of airway obstruction with ProSeal™ laryngeal mask airway.J. Brimacombe, MD Department of Anaesthesia and Intensive Care James Cook University Cairns Base Hospital Cairns, Australia [email protected] C. Keller, MD Department of Anaesthesia and Intensive Care Medicine Leopold-Franzens University Innsbruck, Austria