Clinical performance of the LMA Protector™ airway in moderately obese patients

Influence of patient body weight on the probability of return of spontaneous circulation following out-of-hospital cardiac arrest: an exploratory analysis

Introduction

In addition to key interventions, including bystander CPR and defibrillation, successful resuscitation of out-of-hospital cardiac arrest (OHCA) is also associated with several patient-level factors, including a shockable presenting rhythm, younger age, Caucasian race and female sex. An additional patient-level factor that may influence outcomes is patient weight, yet this attribute has not been extensively studied within the context of OHCA, despite globally increasing obesity rates.

Objective

To assess the relationship between patient weight and return of spontaneous circulation (ROSC) during OHCA.

Methods

This retrospective study included adult patients from a national emergency medical services (EMS) patient record, with witnessed, non-traumatic OHCA prior to EMS arrival from January to December 2020. Logistic regression was used to evaluate the relationship between patient weight and ROSC.

Results

Complete records were available for 9096 patients, of which 64.3% were males and 25.3% were ethnic minorities. The mean age of the participants was 65.01 years (SD = 15.8), with a mean weight of 93.52 kg (SD = 31.5). Altogether, 81.8% of arrests were of presumed cardiac aetiology and 30.3% presented with a shockable rhythm. Bystander CPR and automated external defibrillator (AED) shock were performed in 30.6% and 7.3% of cases, respectively, and 44.0% experienced ROSC. ROSC was less likely with patient weight >100 kg (OR = 0.709, p <0.001), male sex (OR = 0.782, p <0.001), and increasing age and EMS response time (OR = 0.994 per year, p <0.001 and OR = 0.970 per minute, p <0.001, respectively). Patients with shockable rhythms were more likely to achieve ROSC (OR = 1.790, p <0.001), as were patients receiving bystander CPR (OR = 1.170, p <0.001) and defibrillation prior to EMS arrival (OR = 1.658, p <0.001). Although the mean first adrenaline dose (mg/kg) followed a downward trend due to its non-weight-based dosing scheme, the mean total adrenaline dose administered to achieve ROSC demonstrated an upward linear trend of 0.05 mg for every 5 kg of body weight.

Conclusions

Patient weight was negatively associated with ROSC and positively associated with the total adrenaline dose required to attain ROSC.

Comparison of oropharyngeal leak pressure of LMA Protector and LMA ProSeal in anaesthetised paralysed patients - A randomised controlled trial

Background and Aims

In the present study, we hypothesised that the laryngeal mask airway (LMA) Protector would provide higher oropharyngeal leak pressure (OLP) than LMA ProSeal. Thus, we planned this study to compare the clinical performance of LMA Protector and LMA ProSeal in terms of OLP as a primary objective and insertion characteristics as secondary objectives.

Methods

Ninety patients of either gender, aged 18-70 years, were randomised into groups PS (LMA ProSeal) and P (LMA Protector). Following anaesthetic induction, the device was inserted as per group allocation. OLP of both devices was taken as a primary objective. Secondary objectives such as insertion time, ease of insertion, number of attempts required, fibre-optic view grading, amount of air (mL) required to get a cuff pressure (CP) of 60 cm H2O, and CP adjustment required and complications, if any, were also noted. Data were analysed using coGuide statistics software, Version 1 (BDSS Corp. Bangalore, Karnataka, India).

Results

The median (interquartile range) OLP was significantly higher with LMA protector than with LMA ProSeal [33.00 (27.0, 36.0) versus [29.50 (26.0, 32.0) (P = 0.009)]. First-attempt success rate was 95.4% (42/44) in group PS and 93% (40/43) in group P. Insertion time, ease of insertion, and fibre-optic view grading were not different between the groups. Gastric tube placement failed in one patient in group PS and in three patients in group P (P = 0.606). The median amount of air (mL) required to get a CP of 60 cm H2O was 26.5 (20, 28) in group PS and 12 (8,13) in group P (95% confidence interval [CI] =10.808-14.575) (P < 0.001). At all time points, CP was significantly higher, and more CP adjustments were needed in group PS than in group P (P < 0.001). Incidence of blood staining and post-operative sore throat at 1 and 24 h were not different between the groups.

Conclusion

LMA Protector provided a significantly higher OLP and less requirement of CP adjustments but comparable first-attempt success rate, mean insertion time, fibre-optic view, and gastric tube insertion as compared to LMA ProSeal.

Assessing a novel second generation laryngeal mask airway using the 'ADEPT' approach: results from the LMA® Protector™ observational study

To address the problem of lack of clinical evidence for airway devices introduced to the market, the Difficult Airway Society (UK) developed an approach (termed ADEPT; Airway Device Evaluation Project Team) to standardise the model for device evaluation. Under this framework we assessed the LMA Protector, a second generation laryngeal mask airway. A total of 111 sequential adult patients were recruited and the LMA Protector inserted after induction of general anaesthesia. Effective insertion was confirmed by resistance to further distal movement, manual ventilation, and listening for gas leakage at the mouth. The breathing circuit was connected to the airway channel and airway patency confirmed with manual test ventilation at 20 cm H20 (water) pressure for 3 s. Data was collected in relation to the time for placement, intraoperative performance and postoperative performance of the airway device. Additionally, investigators rated the ease of insertion and adequacy of lung ventilation on a 5-point scale. The median (interquartile range [range]) time taken to insertion of the device was 31 (26-40[14-780]) s with the ability to ventilate after device insertion 100 (95% CI 96.7- 100)%. Secondary endpoints included one or more manoeuvres 60.3 (95% CI 50.6-69.5)% cases requiring to assist insertion; a median ease of insertion score of 4 (2-5[3-5]), and a median adequacy of ventilation score of 5 (5-5[4-5]). However, the first time insertion rate failure was 9.9% (95% CI 5.1-17.0%). There were no episodes of patient harm recorded, particularly desaturation. The LMA Protector appears suitable for clinical use, but an accompanying article discusses our reflections on the ADEPT approach to studying airway devices from a strategic perspective.

Comparison of the efficacy of supraglottic airway devices in low-risk adult patients: a network meta-analysis and systematic review

Numerous supraglottic airway device (SADs) have been designed for adults; however, their relative efficacy, indicated by parameters such as adequacy of sealing, ease of application, and postinsertion complications, remains unclear. We conducted a systematic review and network meta-analysis to evaluate the efficacy of various SADs. We searched electronic databases for randomized controlled trials comparing at least two types of SADs published before December 2019. The primary outcomes were oropharyngeal leak pressure (OLP), risk of first-attempt insertion failure, and postoperative sore throat rate (POST). We included 108 studies (n = 10,645) comparing 17 types of SAD. The Proseal laryngeal mask airway (LMA), the I-gel supraglottic airway, the Supreme LMA, the Streamlined Liner of the Pharynx Airway, the SoftSeal, the Cobra Perilaryngeal Airway, the Air-Q, the Laryngeal Tube, the Laryngeal Tube Suction II, the Laryngeal Tube Suction Disposable, AuraGain, and Protector had significantly higher OLP (mean difference ranging from 3.98 to 9.18 cmH₂O) compared with that of a classic LMA (C-LMA). The Protector exhibited the highest OLP and was ranked first. All SADs had a similar likelihood of first-attempt insertion failure and POST compared with the C-LMA. Our findings indicate that the Protector may be the best SAD because it has the highest OLP.Systematic review registration PROSPERO: CRD42017065273.