Brief review: the Cobra Perilaryngeal Airway (CobraPLA and the Streamlined Liner of Pharyngeal Airway (SLIPA) supraglottic airways

Comparison of the Laryngeal Mask Airway ProSeal and the Streamlined Liner of the Pharynx Airway During General Anesthesia: A Systematic Review and Meta-analysis

PURPOSE

The purpose of this article is to compare the safety of the laryngeal mask airway ProSeal (PLMA) and the streamlined liner of the pharynx airway (SLIPA) during general anesthesia.

DESIGN

This study is a systematic review and meta-analysis.

METHODS

Two authors performed searches of Embase, Web of Science, and PubMed to identify clinical trials that compared PLMA and SLIPA in patients receiving general anesthesia. Relative risk (RR) with corresponding 95% confidence intervals (CI) were used to pool the dichotomous data. The mean difference (MD) and the associated 95% CI were applied to pool continuous data. RevMan 5.0 software was used for data analysis.

FINDINGS

A total of 15 studies with 1263 patients were included. There was no significant difference between PLMA and SLIPA in the rate of insertion success on the first attempt (RR = 1.02, 95% CI [0.95, 1.09], P = .59), airway sealing pressure (MD = 0.75, 95% CI [-0.09, 1.58], P = .08) and the incidence of a sore throat (RR = 0.85, 95% CI [0.7, 1.04], P = .12). The insertion time of PLMA was shorter than SLIPA (MD = 5.24, 95% CI [0.51, 9.98], P = .03), and the incidence of bloodstaining on the device was lower (RR = 0.72, 95% CI [0.55, 0.94], P = .02).

CONCLUSIONS

Both devices have a high rate of insertion success on the first attempt and airway sealing pressure. But PLMA has a shorter insertion time and less incidence of blood staining, which is more advantageous than SLIPA.

Extraglottic airway devices: technology update

Extraglottic airway devices (EADs) have revolutionized the field of airway management. The invention of the laryngeal mask airway was a game changer, and since then, there have been several innovations to improve the EADs in design, functionality, safety and construction material. These have ranged from changes in the shape of the mask, number of cuffs and material used, like rubber, polyvinylchloride and latex. Phthalates, which were added to the construction material in order to increase device flexibility, were later omitted when this chemical was found to have serious adverse reproductive outcomes. The various designs brought out by numerous companies manufacturing EADs resulted in the addition of several devices to the airway market. These airway devices were put to use, many of them with inadequate or no evidence base regarding their efficacy and safety. To reduce the possibility of compromising the safety of the patient, the Difficult Airway Society (DAS) formed the Airway Device Evaluation Project Team (ADEPT) to strengthen the evidence base for airway equipment and vet the new extraglottic devices. A preuse careful analysis of the design and structure may help in better understanding of the functionality of a particular device. In the meantime, the search for the ideal EAD continues.

Laryngeal mask airway without muscle relaxant in femoral head replacement in elderly patients

The number of elderly patients undergoing femoral head replacement surgeries is on the increase. These patients often suffer from comorbidity such as cardiovascular and cerebrovascular complications, which limits the ability of medical teams to employ anesthesia. Thus, alternative methods are required. The aim of this study was to examine the advantage of laryngeal mask airway (LMA) in the absence of muscle relaxant in elderly patients undergoing femoral head replacement operations. Fifty patients (27 males and 23 females) undergoing femoral head replacements were selected for the study between March 2013 and May 2014. The mean value for the age in this group was 74.6±12.5 years. The patients were randomly distributed into two groups of 25. One group was designated as the treatment group and the second group as the control group. For the treatment group, LMA without muscle relaxant was used, and the control group received routine anesthesia. Variations in heart rate (HR), mean arterial pressure (MAP) and oxygen saturation (SPO₂) in the two groups were monitored at different times. Clinical efficacy and muscle relaxation effects were also analyzed. For the treatment group, the HR, MAP and SPO₂ measurements did not reveal any significant variation while these values in the control group demonstrated important dissimilarities. Time to recovery, time to extubation and incidence of throat pain in the treatment group were all markedly decreased as compared to those in control group. The operation time in the treatment group was not significantly different to that of control group. The satisfaction of the muscle relaxation effect in the treatment group was significantly higher than that in the control group while the incidence of adverse reactions was not considerably different. In conclusion, the use of LMA without using muscle relaxant in femoral head replacement surgeries performed on elderly patients showed to be effective and safe.

Airway management evolution - in a search for an ideal extraglottic airway device

Extraglottic airway devices (EADs) are commonly used equipment for airway maintenance during elective procedures under general anaesthesia. They may be used also in other indications such as conduit for tracheal intubation or rescue airway device in prehospital medicine. Current classifications of the EADs lack systematic approach and therefore classification according to the sealing sites and sealing mechanisms is suggested in this review article. Modern EADs are disposable, latex-free devices made of plastic materials most commonly from polyvinylchloride (PVC). The bowl of uncuffed sealers is manufactured from different materials such as thermoplastic elastomers or ethylene-vinyl-acetate co-polymer. EADs create various physical forces exerted on the adjacent tissues which may contribute to different sealing characteristic of particular device or to variable incidence of postoperative complications. Desired features of an ideal EAD involve easy insertion, high insertion success rate even by inexperienced users, protection against aspiration of gastric contents and low incidence of postoperative complications such as sore throat, hoarseness, cough or swallowing difficulties.

Severe hoarseness associated with the streamlined liner of the pharyngeal airway (SLIPATM)

Hoarseness is a common post-operative complication in patients who receive general anesthesia. In most cases, the symptoms are temporary and improve within several days. This report describes two patients with prolonged hoarseness following use of the streamlined liner of the pharyngeal airway (SLIPATM). We present the first case of a 56-year-old female patient who developed arytenoid cartilage dislocation resulting in prolonged hoarseness and dysphagia after using a SLIPA™ during a laparoscopic myomectomy. In the second case, we report on a 65-year-old male patient who was scheduled for a laparoscopic cholecystectomy. Left vocal fold paralysis or paresis resulting from recurrent laryngeal nerve injury associated with use of a SLIPA™ caused persistent hoarseness. It should be noted that recurrent laryngeal nerve injury or arytenoid cartilage dislocation are possible complications associated with use of the SLIPATM in case of persistent hoarseness.

Comparison of streamlined liner of the pharynx airway (SLIPA ™) and laryngeal mask airway: a systematic review and meta-analysis

We performed a systematic review to compare the efficacy and safety of the streamlined liner of the pharynx airway and laryngeal mask airway used in adults during general anaesthesia. We included 14 studies with studies with 1273 patients in total. There was no evidence of a difference between the two devices in insertion success rate on the first attempt (13 studies, 1143 patients), insertion time (seven studies, 576 patients), ease of insertion (five studies, 466 patients), oropharyngeal leak pressure (eight studies, 771 patients) and the quality of the fibreoptic view of the larynx through the device (three studies, 281 patients). The relative risk (95% CI) of bloodstaining of the device (nine studies, 859 patients) was 2.09 (1.46-3.00) for the streamlined liner of the pharynx airway compared with the laryngeal mask airway. Other adverse events were comparable. Subgroup analysis suggested that the insertion by novice users might be faster and more successful with the streamlined liner of the pharynx airway than the laryngeal mask airway; however, this was from only two studies and 186 patients. The method of size selection of the streamlined liner of the pharynx airway device might also affect the speed of insertion: choosing according to the width of the patient's thyroid cartilage, rather than height, may produce better results.

Extraglottic airway devices: A review

Extraglottic airway devices (EAD) have become an integral part of anesthetic care since their introduction into clinical practice 25 years ago and have been used safely hundreds of millions of times, worldwide. They are an important first option for difficult ventilation during both in-hospital and out-of-hospital difficult airway management and can be utilized as a conduit for tracheal intubation either blindly or assisted by another technology (fiberoptic endoscopy, lightwand). Thus, the EAD may be the most versatile single airway technique in the airway management toolbox. However, despite their utility, knowledge regarding specific devices and the supporting data for their use is of paramount importance to patient's safety. In this review, number of commercially available EADs are discussed and the reported benefits and potential pitfalls are highlighted.

Laryngeal view and temperature measurements while using the perilaryngeal airway (Cobra-PLUS™) in children

INTRODUCTION

The Cobra-PLUS™ perilaryngeal airway (CP) is a modification of the Cobra perilaryngeal airway. It has a distal curve for easier placement and a thermistor on the pharyngeal cuff. We assessed the orientation of the larynx to the CP and compared temperatures measured using CP to temporal arterial (TA) and infrared tympanic (T) thermometers.

METHODOLOGY

American Society of Anesthesiologists (ASA) physical status 1 and 2 children 0-18 years old undergoing general anesthesia using CP were grouped into different weight cohorts. A fiberoptic scope was inserted through the CP, and laryngeal views were recorded and graded off line. Temperatures were measured from the CP, TA, and T at 15-min intervals for four readings or until the end of surgery. The CP was removed, while the patient was deeply anesthetized.

RESULTS

Eighty subjects were analyzed. 87.5% (cohort range 75-95%) had an unobstructed view of the larynx. No serious adverse effects noted. Three hundred and sixteen temperature data points were recorded for each measured site. CP temperatures were consistently lower than TA and T with a bias of 0.9 and 0.6°C, respectively. Using temperatures measured at time 0 and 15 min, CP was associated with a larger intraclass correlation coefficient and smaller repeatability coefficient when compared to TA or T (ICC 0.65, 0.46. 0.44 and RC 0.78, 1, 1.36, respectively), indicating it had a better measure and remeasure reliability.

CONCLUSION

The CP has a better orientation to the larynx compared with its previous version. It may be used to reliably trend intraoperative temperatures.

Successful anesthetic management of a child with blepharophimosis syndrome and atrial septal defect for reconstructive ocular surgery

Blepharophimosis syndrome is an autosomal dominant disorder characterized by eyelid malformation, involvement of reproductive system and abnormal facial morphology leading to difficult airway. We report a rare association of blepharophimosis syndrome and atrial septal defect in a 10-year-old girl who came for reconstruction surgery of eyelid. The child had dyspnea on exertion. Atrial septal defect was identified preoperatively by clinical examination and echocardiography. Anesthesia management was complicated by failure in laryngeal mask airway placement and Cobra perilaryngeal airway was subsequently used.

Supraglottic airway devices in the ambulatory setting

Supraglottic airway devices (SGAs) offer certain advantages over endotracheal intubation, making them particularly well suited for the specific demands of outpatient anesthesia. Patients may tolerate the placement and maintenance of an SGA at a lower dose of anesthetic than that needed for an endotracheal tube; neuromuscular blocking agents are rarely necessary for airway management with an SGA; the incidence of airway morbidity is lower with SGAs than with endotracheal tubes; and SGAs may facilitate faster recovery and earlier discharge of patients. Two limitations of SGAs are incomplete protection against aspiration of gastric contents and inadequate delivery of positive pressure ventilation. Newer variants of the original laryngeal mask airway, the LMA Classic (LMA North America, Inc), as well as an array of other recently developed SGAs, aim to address these limitations. Their utility and safety in specific patient populations (eg, the morbidly obese) and during certain procedures (eg, laparoscopic surgery) remain to be determined.