A comparison of the ProSeal and classic laryngeal mask airways for airway management by inexperienced personnel after manikin-only training

Evaluation of the SLIPA™ (Streamlined Liner of the Pharynx Airway), a Single Use Supraglottic Airway Device, in 60 Anaesthetized Patients Undergoing Minor Surgical Procedures

The Streamlined Liner of the Pharyngeal Airway, SLIPA™ (Hudson RCI) is a new disposable supraglottic airway device that has no inflatable cuff and has features designed to reduce aspiration risk. This study aimed to assess the insertion success and effectiveness of the SLIPA™ in 60 patients who presented for elective surgery. Ethics committee approval was obtained. Patients were excluded if they were less than 18 years, had not provided written consent or were at risk of pulmonary aspiration. The first 20 SLIPA™ were inserted by the principal investigator (Group A) followed by another 40 inserted by medical officers and anaesthetists of varying experience (Group B). Twenty-one males and 39 females were recruited into the study. Median time to ventilation was 20.4 seconds in Group A (range 12.9-109) and 24.8 seconds in Group B (range 8.2-82.5). Overall success rate was 100% in Group A and 92.5% in Group B. The lowest recorded SpO2 was 91% in Group B. The incidence of blood and sore throat score >3 (0-10 scale) was 23% and 7% respectively (Groups A and B). Group B reported that use of the device was very easy in 16%, easy in 76%, difficult in 5%, and very difficult in 3%. The SLIPA™ proved to be a reliable airway providing adequate ventilation in both spontaneous breathing and assisted respiration. Most users found the SLIPA™ to be easy or very easy to use.

Competence in the use of supraglottic airways by Australian surf lifesavers for cardiac arrest ventilation in a manikin

OBJECTIVES

Lifesavers in Australia are taught to use pocket mask (PM) rescue breathing and bag valve mask (BVM) ventilation, despite evidence that first responders might struggle with these devices. Novices have successfully used the Laryngeal Mask Airway (LMA) Supreme and iGel devices previously, but there has been no previous comparison of the ability to train lifesavers to use the supraglottic airways compared to standard techniques for cardiac arrest ventilation.

METHODS

The study is a prospective educational intervention whereby 113 lifesavers were trained to use the LMA and iGel supraglottic airways. Comparisons were made to standard devices on plastic manikins. Successful ventilation was defined as achieving visible chest rise.

RESULTS

The median time to first effective ventilation was similar between the PM (16 s, 95% confidence interval 16-17 s), BVM (17 s, 16-17 s) and iGel devices (18 s, 16-20 s), but longer for the LMA (36 s, 33-38 s). The iGel frequently failed to achieve ventilation (10%) compared with the PM (1%, P < 0.01) and LMA (3%, P < 0.01) but was not worse than the BVM (3%, P < 0.57). Hands-off time was similar between the BVM, LMA and iGel (10 s for each device), but worse for the PM (13 s, P = 0.001).

CONCLUSION

Lifesavers using the PM and BVM perform ventilation for cardiopulmonary resuscitation well. There appears to be a limited role for supraglottic airway devices because of limitations in terms of time to first effective ventilation and reliability. Clinical validation of manikin data with live resuscitation performance is required.

Defining the learning curve for endotracheal intubation using direct laryngoscopy: A systematic review

More than two failed intubation attempts and failed endotracheal intubations (ETIs) are associated with severe complications and death. The aim of this review was to determine the number of ETIs a health care provider in training needs to perform to achieve proficiency within two attempts. A systematic search of the literature was conducted covering the time frame of January 1990 through July 2014. We identified 13 studies with a total of 1462 students who had attempted to intubate 19,108 patients. This review shows that in mostly elective circumstances, at least 50 ETIs with no more than two intubation attempts need to be performed to reach a success rate of at least 90%. However, the evidence is heterogeneous, and the incidence of difficult airways in non-elective settings is up to 20 times higher compared to elective settings. Taking this factor into account, training should include a variety of exposures and should probably exceed 50 ETIs to successfully serve the most vulnerable patients.

Comparison of five 2nd-generation supraglottic airway devices for airway management performed by novice military operators

OBJECTIVES

Five different second-generation supraglottic airway devices, ProSeal LMA, Supreme LMA, i-gel, SLIPA, and Laryngeal Tube Suction-D, were studied. Operators were inexperienced users with a military background, combat lifesavers, nurses, and physicians.

METHODS

This was a prospective, randomized, single-blinded study. Devices were inserted in the operating room in low light conditions after induction of general anesthesia. Primary outcome was successful insertion on the first attempt while secondary aims were insertion time, number of attempts, oropharyngeal seal pressure, ease of insertion, fibre optic position of device, efficacy of ventilation, and intraoperative trauma or regurgitation of gastric contents.

RESULTS

In total, 505 patients were studied. First-attempt insertion success rate was higher in the Supreme LMA (96%), i-gel (87.9%), and ProSeal LMA (85.9%) groups than in the Laryngeal Tube Suction-D (80.6%) and SLIPA (69.4%) groups. Insertion time was shortest in the Supreme LMA (70.4 ± 32.5 s) and i-gel (74.4 ± 41.1 s) groups (p < 0.001). Oropharyngeal seal pressures were higher in the Laryngeal Tube Suction-D and ProSeal LMA groups than in other three devices.

CONCLUSIONS

Most study parameters for the Supreme LMA and i-gel were found to be superior to the other three tested supraglottic airway devices when inserted by novice military operators.

Feasibility of LMA Supreme for airway management in unconscious patients by ALS paramedics

Background

Airway management to ensure sufficient gas exchange is of major importance in emergency care. The accepted basic technique is to maintain an open airway and perform artificial ventilation in emergency situations is bag-valve mask (BVM) ventilation with manual airway management without airway adjuncts or with an oropharyngeal tube (OPA) only. Endotracheal intubation (ETI) is often referred to as the golden standard of airway management, but is associated with low success rates and significant insertion-related complications when performed by non-anaesthetists. Supraglottic devices (SADs) are one alternative to ETI in these situations, but there is limited evidence regarding the use of SAD in non-cardiac arrest situations. LMA Supreme (LMA-S) is a new SAD which theoretically has an advantage concerning the risk of aspiration due to an oesophageal inlet gastric tube port.

Methods

Forty paramedics were recruited to participate in the study. Adult (>18 years) patients, unconscious due to medical or traumatic cause with a GCS score corresponding to 3–5 and needed airway management were included in the study. Our aim was to study the feasibility of LMA-S as a primary airway method in unconscious patients by advanced life support (ALS) trained paramedics in prehospital care.

Results

Three regional Emergency Medical Service (EMS) services participated and 21 patients were treated during the survey. The LMA-S was placed correctly on the first attempt in all instances 21/21 (100%), with a median time to first ventilation of 9.8 s. Paramedics evaluated the insertion to be easy in every case 21/21 (100%). Because of air leak later in the patient care, the LMA-S was exchanged to an LT-D in two cases and to ETI in three cases (23.81%) by the paramedics. Regurgitation occurred after insertion two times out of 21 (9.52%) and in one of these cases (4.76%), paramedics reported regurgitation inside the LMA-S.

Conclusion

We conclude that the LMA-S seems to be relatively easy and quick to insert in unconscious patients by paramedics. However, we found out that there were ventilation related problems with the LMA-S. Further studies are warranted.

Does a 4 diagram manual enable laypersons to operate the Laryngeal Mask Supreme®? A pilot study in the manikin

Background

Bystander resuscitation plays an important role in lifesaving cardiopulmonary resuscitation (CPR). A significant reduction in the "no-flow-time", quantitatively better chest compressions and an improved quality of ventilation can be demonstrated during CPR using supraglottic airway devices (SADs). Previous studies have demonstrated the ability of inexperienced persons to operate SADs after brief instruction. The aim of this pilot study was to determine whether an instruction manual consisting of four diagrams enables laypersons to operate a Laryngeal Mask Supreme^® (LMAS) in the manikin.

Methods

An instruction manual of four illustrations with speech bubbles displaying the correct use of the LMAS was designed. Laypersons were handed a bag containing a LMAS, a bag mask valve device (BMV), a syringe prefilled with air and the instruction sheet, and were asked to perform and ventilate the manikin as displayed. Time to ventilation was recorded and degree of success evaluated.

Results

A total of 150 laypersons took part. Overall 145 participants (96.7%) inserted the LMAS in the manikin in the right direction. The device was inserted inverted or twisted in 13 (8.7%) attempts. Eight (5.3%) individuals recognized this and corrected the position. Within the first 2 minutes 119 (79.3%) applicants were able to insert the LMAS and provide tidal volumes greater than 150 ml (estimated dead space). Time to insertion and first ventilation was 83.2 ± 29 s. No significant difference related to previous BLS training (P = 0.85), technical education (P = 0.07) or gender could be demonstrated (P = 0.25).

Conclusion

In manikin laypersons could insert LMAS in the correct direction after onsite instruction by a simple manual with a high success rate. This indicates some basic procedural understanding and intellectual transfer in principle. Operating errors (n = 91) were frequently not recognized and corrected (n = 77). Improvements in labeling and the quality of instructional photographs may reduce individual error and may optimize understanding.

The McIvor blade improves insertion of the LMA ProSeal™ in children

BACKGROUND

The McIvor blade, a tongue retractor with a thin curved blade, is used to improve the operating field during a tonsillectomy. We compared the success rate and incidence of complications between digital insertion and McIvor blade-guided insertion of the laryngeal mask airway (LMA™) ProSeal™ when performed by anesthesia residents in children.

METHODS

A total of 134 anesthetized non-paralyzed pediatric patients were included in the study. Patients were allocated randomly to one of two groups, i.e., Digital group (LMA ProSeal insertion using the digital insertion technique) or McIvor group (LMA ProSeal insertion using the Mclvor blade-guided technique). All patients were managed by anesthesia residents who were unskilled in using each technique. We assessed success rates of insertion at the first attempt, insertion time for an effective airway, and postoperative blood staining.

RESULTS

The success rate of insertion at the first attempt was higher in the McIvor group than in the Digital group (97% vs 78%, respectively; P = 0.003), and insertion time with a successful first attempt was shorter in the McIvor group than in the Digital group (20.5 [4.5] sec vs 22.8 [6.7] sec, respectively; P = 0.021). The overall insertion time for an effective airway was also shorter in the McIvor group than in the Digital group (20.9 [5.7] sec vs 26.0 [9.8] sec, respectively; P < 0.001). Blood staining was more frequent in the Digital group than in the McIvor group (23% vs 6%, respectively; P = 0.035).

CONCLUSION

When inserting the LMA ProSeal in children, anesthesia residents were more successful using the McIvor blade-guided insertion technique than using the digital insertion technique. (ClinicalTrials.gov number, NCT01191619).

Comparison of Supreme(®) and Soft Seal(®) laryngeal masks for airway management during cardiopulmonary resuscitation in novice doctors: a manikin study

PURPOSE

In the 2005 American Heart Association (AHA) guidelines, the laryngeal mask (LMA) was proposed as an alternative to tracheal intubation for cardiopulmonary resuscitation (CPR). We compared the utility of a newly developed LMA, the Supreme(®) (Supreme), with a conventional LMA, the Soft Seal(®) (Soft Seal).

METHODS

A total of 19 novice doctors in our anesthesia department performed insertion of the Supreme or Soft Seal on a manikin with or without chest compression. Insertion time and number of attempts for successful ventilation were measured. After successful ventilation, the amount of air entering the stomach and maximum ventilation pressure were measured. The subjective difficulty of using the devices was also measured.

RESULTS

The ventilation success rate of first insertion did not differ between the Supreme and Soft Seal without chest compression. However, the success rate was significantly lower with the Soft Seal than the Supreme during chest compression. Insertion time was lengthened by chest compression with the Soft Seal, but not with the Supreme. Maximum ventilation pressure was higher with the Supreme than the Soft Seal. The amount of air entering the stomach was significantly lower with the Supreme than the Soft Seal. The Supreme also scored better than the Soft Seal on a visual analog scale of subjective difficulty in insertion.

CONCLUSIONS

The Supreme is an effective device for airway management during chest compression.

A comparison of the laryngeal mask airway with facemask and oropharyngeal airway for manual ventilation by critical care nurses in children

The laryngeal mask airway is included as a first line airway device during adult resuscitation by first responders. However, there is little evidence for its role in paediatric resuscitation. Using anaesthetised children as a model for paediatric cardiopulmonary arrest, we compared the ability of critical care nurses to manually ventilate the anaesthetised child via the laryngeal mask airway compared with the facemask and oropharyngeal airway. The airway devices were inserted in random order and chest expansion was measured using an ultrasound distance transducer. The critical care nurses were able to place the laryngeal mask airway and achieve successful ventilation in 82% of children compared to 70% using the facemask and oropharyngeal airway, although the difference was not statistically significant (p = 0.136). The median time to first successful breath using the laryngeal mask airway was 39 s compared to 25 s using the facemask (p < 0.001). In this group of nurses, we did not show a difference in ventilation via a laryngeal mask airway or facemask, although facemask ventilation was achieved more quickly.

Randomized comparison of the SLIPA (Streamlined Liner of the Pharynx Airway) and the SS-LM (Soft Seal Laryngeal Mask) by medical students

OBJECTIVE

The aim of the study was to compare the Streamlined Liner of the Pharynx Airway (SLIPA; Hudson RCI), a new supraglottic airway device, with the Soft Seal Laryngeal Mask (SS-LM; Portex) when used by novices.

METHODS

Thirty-six medical students with no previous airway experience, received manikin training in the use of the SLIPA and the SS-LM. Once proficient, the students inserted each device in randomized sequence, in two separate patients in the operating theatre. Only two insertion attempts per patient were allowed. Students were assessed in terms of: device preference; success or failure; success at first attempt and time to ventilation.

RESULTS

Sixty-seven per cent of the students preferred to use the SLIPA (95% confidence interval 49-81%). The SLIPA was successfully inserted (one or two attempts) in 94% of patients (34/36) and the SS-LM in 89% (32/36) (P = 0.39). First attempt success rates were 83% (30/36) and 67% (24/36) in the SLIPA and SS-LM, respectively (P = 0.10). Median time to ventilation was shorter with the SLIPA (40.6 s) than with the SS-LM (66.9 s) when it was the first device used (P = 0.004), but times were similar when inserting the second device (43.8 s vs 42.9 s) (P = 0.75).

CONCLUSIONS

In the present study novice users demonstrated high success rates with both devices. The SLIPA group achieved shorter times to ventilation when it was the first device they inserted, which might prove to be of clinical significance, particularly in resuscitation attempts. Although the Laryngeal Mask has gained wide recognition for use by both novice users and as a rescue airway in failed intubation, the data presented here suggest that the SLIPA might also prove useful in these areas.

Guided Insertion of the ProSeal Laryngeal Mask Airway Is Superior to Conventional Tracheal Intubation by First-Month Anesthesia Residents After Brief Manikin-Only Training

In the following pilot study, we compared conventional laryngoscope-guided tracheal intubation (tracheal intubation) and laryngoscope-guided, gum elastic bougie-guided ProSeal laryngeal mask airway insertion (guided ProSeal) for airway management by first-month anesthesia residents after brief manikin-only training. Five first-month residents with no practical experience of airway management were observed performing these techniques in 200 ASA I-II anesthetized, paralyzed adults. Each resident managed 40 patients, 20 in each group, in random order. The number of insertion attempts, effective airway time, ventilatory capability during pressure-controlled ventilation set at 15 cm H2O, airway trauma, and skill acquisition were studied. Data were collected by unblinded observers. Insertion was more frequently successful (100% versus 65%) and effective airway time was shorter (41 +/- 24 s versus 89 +/- 62 s) in the guided ProSeal group (both P < 0.0001). Expired tidal volume was larger (730 +/- 170 mL versus 560 +/- 140 mL) and end-tidal CO(2) lower (33 +/- 4 mm Hg versus 37 +/- 5 mm Hg) in the guided ProSeal group during pressure controlled ventilation (both P < 0.0001). Blood staining was more frequent on the laryngoscope (24% versus 2%; P < 0.0001) in the tracheal intubation group. There was evidence for skill acquisition in both groups. We conclude that laryngoscope-guided, gum elastic bougie-guided insertion of the ProSeal laryngeal mask airway is superior to conventional laryngoscope-guided tracheal intubation for airway management in terms of insertion success, expired tidal volume, and airway trauma by first-month anesthesia residents after brief manikin-only training. The guided ProSeal technique has potential for cardiopulmonary resuscitation by novices when conventional intubation fails.

New airways for resuscitation?

Over the last 15 years supraglottic airway devices (SADs), most notably the classic laryngeal mask airway (LMA) have revolutionised airway management in anaesthesia. In contrast for resuscitation, both in and outside hospital, facemask ventilation and tracheal intubation remain the mainstays of airway management. However there is evidence that both these techniques have complications and are often poorly performed by inexperienced personnel. Tracheal intubation also has the potential to cause serious harm or death through unrecognised oesophageal intubation. SADs may have a role in airway management for resuscitation as first responder devices, rescue devices or for use during patient extraction. In particular they may be beneficial as the level of skill required to use the device safely may be less than for the tracheal tube. Concerns have been expressed over the ability to ventilate the lungs successfully and also the risk of aspiration with SADs. The only SADs recommended by ILCOR in its current guidance are the classic LMA and combitube. Several SADs have recently been introduced with claims that ventilation and airway protection is improved. This pragmatic review examines recent developments in SAD technology and the relevance of this to the potential for using SADs during resuscitation. In addition to examining research directly related to resuscitation both on bench models and in patients the review also examines evidence from anaesthetic practice. SADS discussed include the classic, intubating and Proseal LMAs, the combitube, the laryngeal tube, laryngeal tube sonda mark I and II and single use laryngeal masks.

Comparison of airway management with the intubating laryngeal mask, laryngeal tube and CobraPLA by paramedical students in anaesthetized patients

BACKGROUND

Because of the importance of airway management in emergency care, alternative methods with shorter learning curves for inexperienced personnel have been looked for as a substitute for endotracheal intubation (ETI).

METHODS

We compared the success of insertion, oxygenation and ventilation of the intubating laryngeal mask (ILMA), laryngeal tube (LT) and CobraPLA (COB) in anaesthetized patients when used by paramedical students. After informed consent, 96 patients were monitored and anaesthetized for general surgery without the use of a muscle relaxant. After the induction of anaesthesia, 32 paramedical students inserted the ILMA, LT or COB in a random order and ventilated the patient for a 60-s period. The number of insertion attempts, the time needed for insertion, and oxygenation and ventilation parameters were recorded. The students gave a subjective evaluation of the airway devices after the test.

RESULTS

Twenty-four of the 32 students (75%) successfully inserted ILMA at the first attempt, compared with 14 of 32 (44%) for LT and seven of 32 (22%) for COB (P<0.001, ILMA vs. COB). One student failed to insert ILMA after all three attempts, compared with seven of 32 (21%) using LT and seven of 32 (21%) using COB (P=not significant). Oxygenation and ventilation parameters did not differ between the groups after successful insertion.

CONCLUSION

Clinically inexperienced paramedical students can successfully use ILMA in anaesthetized patients. Further investigations are warranted to study whether ILMA or LT can replace ETI in emergency airway management when used by inexperienced medical or paramedical staff.

A Comparison of the Laryngeal Tube and Bag-Valve Mask Ventilation by Emergency Medical Technicians: A Feasibility Study in Anesthetized Patients

Airway management is of major importance in emergency care. The basic technique for all health care providers is bag-valve mask (BVM) ventilation, which requires skill and may be difficult to perform. Endotracheal intubation, which is the advanced method for securing the airway, is a demanding technique that has been shown to be associated with infrequent success, even when used by experienced paramedical personnel. Therefore, alternative airway devices have been sought. The use of the laryngeal tube (LT) by experienced anesthesia personnel had been studied in anesthetized patients and manikins in emergency medical training. We decided to evaluate the ability of inexperienced firefighter-emergency medical technician students (fire-EMT) to insert the LT or perform BVM in anesthetized patients. Thirty fire-EMTs randomly inserted the LT (n = 15) and performed 1 min of ventilation or used the BVM (n = 15). We found that all students successfully (100%) inserted the LT. Those who inserted the LT on the first attempt (73%) required 48.2 +/- 14.7 s for the insertion. Both the LT and BVM provided adequate oxygenation and ventilation. In this study, we found that inexperienced fire-EMT students inserted LT and performed 1-min ventilation with a reasonable success rate and insertion time in anesthetized patients.

The proseal™laryngeal mask airway: a review of the literature

PURPOSE

To analyze and summarize the published literature relating to the ProSeal LMA (PLMA): a modification of the "classic LMA" (cLMA) with an esophageal drain tube (DT), designed to improve controlled ventilation, airway protection and diagnosis of misplacement.

SOURCE

Articles identified through Medline and EMBASE searches using keywords "Proseal", "ProSeal" and "PLMA". Hand searches of these articles and major anesthetic journals from January 1998 to March 2005.

PRINCIPAL FINDINGS

Searches identified 59 randomized controlled trials or clinical studies and 79 other publications. Compared to the cLMA, PLMA insertion takes a few seconds longer. First attempt insertion success for the PLMA is lower, but overall success is equivalent. Airway seal is improved by 50%. The DT enables early diagnosis of mask misplacement, allows gastric drainage, reduces gastric inflation and may vent regurgitated stomach contents. Evidence suggests, but does not prove, that the correctly placed PLMA reduces aspiration risk compared with the cLMA. PLMA use is associated with less coughing and less hemodynamic disturbance than use of a tracheal tube (TT). Comparative trials of the PLMA with other supraglottic airways favour the PLMA. Clinicians have extended the use of the PLMA inside and outside the operating theatre including use for difficult airway management and airway rescue.

CONCLUSIONS

The PLMA has similar insertion characteristics and complications to other laryngeal masks. The DT enables rapid diagnosis of misplacement. The PLMA offers significant benefits over both the cLMA and TT in some clinical circumstances. These and clinical experience with the PLMA are discussed.

The Proseal™ LMA is a useful rescue device during failed rapid sequence intubation: two additional cases

PURPOSE

We report two cases where the ProSeal laryngeal mask airway (PLMA) was successfully used as a rescue device, after failed tracheal intubation, during rapid sequence induction.

CLINICAL FINDINGS

The first case involved a 31-yr-old primigravida presenting for emergency Cesarean section for severe fetal distress. She had a grade 3 larynx and airway edema was observed during laryngoscopy. Attempts with a McCoy blade and gum elastic bougie failed to secure the airway. A size 4 PLMA was inserted with good airway control and surgery proceeded uneventfully. The second case involved a 51-yr-old man presenting for appendectomy. Following failed attempts at intubation, a size 5 PLMA was successful in securing his airway and surgery proceeded uneventfully.

CONCLUSIONS

The correctly placed PLMA has potential advantages over the cLMA for airway rescue in the circumstance of failed emergency intubation in a patient with a potentially full stomach. In the two cases reported, the PLMA provided effective rescue of the airway.