A Randomized Trial of Laryngeal Mask Airway in Neonatal Resuscitation

The endotracheal tube (ETT) and the laryngeal mask airway (LMA) are possible strategies for airway management during tracheal resection and reconstruction for tracheal and laryngotracheal stenosis. The goal of the study was to analyse and compare outcomes in the LMA and ETT groups. Between 2003 and 2020, a total of 184 patients affected by postintubation, post-tracheostomy and idiopathic stenosis who had tracheal or laryngotracheal resections and reconstructions via a cervicotomy were retrospectively enrolled in this single-centre study. In 29 patients, airway management was achieved through LMA during tracheal surgery, whereas in 155 patients, it was achieved through ETT. A case-control matching analysis was performed with a 1:1 ratio, according to age, gender, body mass index, aetiology and length of stenosis (1-4 cm), resulting in 22 patients managed through LMA (LMA group) matched with 22 patients managed through ETT (ETT group). No significant differences were found in the reintubation rate, 30-day mortality and postoperative length of stay. Operative time was shorter in patients with LMA (96.23 ± 34.72 min in the ETT group vs 76.14 ± 26.94 min in the LMA group; P = 0.043). Intensive care unit (ICU) admission rate and stay were lower in the LMA group [18 in the ETT group vs 8 in the LMA group, odds ratio = 10.17, confidence interval (CI) 95% 1.79-57.79; P = 0. 009; 22.77 ± 16.68 h in ETT group vs 9.23 ± 13.51 h in LMA group; P = 0.005]. Dysphonia was more frequent in the ETT group than in the LMA group (20 in the ETT group vs 11 in the LMA group, odds ratio = 13.79, CI 95% 1.86-102; P = 0.010). LMA is a feasible option for airway management in tracheal surgery, with lower operative time, ICU admission rate, ICU length of stay and postoperative dysphonia occurrence.

We compared exposure to sevoflurane (SEV) and nitrous oxide (N(2)O) during ventilation using the cuffed oropharyngeal airway (COPA) with waste gas exposure using a conventional face mask (FM) without any additional airways or face straps and with the laryngeal mask airway (LMA). Trace concentrations of SEV and N(2)O were assessed by using a direct reading spectrometer during 33 surgical procedures under general anesthesia. Measurements were made at the patients' mouths and in the anesthesiologists' breathing zones. Mean +/- SD concentrations of SEV and N(2)O measured at the patients' mouths were comparable in the COPA (SEV, 8.1 +/- 12.2 ppm; N(2)O, 213.3 +/- 289.2 ppm) and LMA (SEV, 18.5 +/- 25.8 ppm; N(2)O, 283.4 +/- 361.0 ppm) groups but differed significantly from the FM group (SEV, 46.5 +/- 19.6 ppm; N(2)O, 750.7 +/- 308.3 ppm). These values resulted in a comparable contamination of the anesthesiologists' breathing zones (SEV, 0.5 +/- 0.2 ppm; N(2)O, 5.7 +/- 4.8 ppm) for the COPA group, compared with the LMA group (SEV, 1.0 +/- 0.9 ppm; N(2)O, 12.2 +/- 14.3 ppm). This differed significantly from the FM group (SEV, 2.2 +/- 0.9 ppm; N(2)O, 37.5 +/- 14.3 ppm). We conclude that the use of the COPA during short surgical interventions has an occupational safety comparable to that of the LMA and that both resulted in less contamination through waste anesthetic gases. Therefore, the COPA may be a valuable alternative to the conventional FM. In this study, we have shown that the occupational exposure to waste anesthetic gases is comparable when using the cuffed oropharyngeal airway (COPA) and the laryngeal mask airway and is increased when using the face mask. Therefore, the COPA may be a valuable alternative to the conventional face mask during short surgical procedures.

Reply to Letter: “Laryngeal Mask Airway and newborn resuscitation” [Vincenzo Zanardo

Laryngeal mask airway and the ASA difficult airway algorithm.

Background:Laryngeal mask airway (LMA) insertion provokes fewer stress responses than endotracheal intubation. This study aimed to evaluate the LMA Protector for assessing improvements in intraoperative hemodynamic stability and to reduce postoperative discomfort compared with endotracheal intubation in laparoscopic cholecystectomy.Methods:Fifty-six patients who underwent laparoscopic cholecystectomy while under sevoflurane-based general anesthesia were randomly allocated to airway management using LMA (LMA group) or endotracheal tube (ETT group). Heart rate, blood pressure, and peak airway pressure were recorded before and after carboperitoneum. Postoperative pain and analgesic requirements were assessed, in addition to nausea, hoarseness, dysphonia, and sore throat during the first 1 hour postoperatively and until postoperative day 1.Results:All patients underwent successful LMA or ETT placement within 2 attempts. There was no difference in highest mean (SD) peak airway pressure during carboperitoneum between the LMA and ETT groups (17.7 [2.8] mm Hg vs 19.1 [3.8] mm Hg, P = .159, respectively). The incidence of high systolic blood pressure and bradycardia was higher in the LMA group. The highest pain scores 1 hour postoperatively and on postoperative day 1 were lower in the LMA group than in the ETT group (3.9 [2.0] vs 5.4 [2.3], P = .017 and 5.6 [1.9] vs 6.7 [1.7], P = .042, respectively); requirements for analgesics were similar in the 2 groups. The incidence of nausea was lower in the LMA group than in the ETT group until postoperative day 1 (4/28 [14%] vs 12/28 [43%], P = .031, respectively).Conclusion:The LMA Protector was an effective ventilator device associated with fewer intraoperative hemodynamic stress responses and improved the quality of early recovery after laparoscopic cholecystectomy.

Aim: Chronic otitis media is a common disease characterized by a tympanic membrane perforation and conductive hearing loss. Tympanoplasty is performed to provide a healthy middle ear and to create an intact eardrum. In recent years, endoscopic tympanoplasty has become more popular for the repair of the tympanic membrane. This method saves time for the surgeon and provides a comfortable opportunity for the patient.Endotracheal intubation (ET) and laryngeal mask airway (LMA) are two different airway systems used in general anesthesia. It is known that LMA provides shorter operating times for surgeries requiring general anesthesia.The aim of this study was to evaluate the outcomes of endoscopic tympanoplasty in patients who underwent endoscopic tympanoplasty with LMA or ET anesthesia, and to compare this method that regards to graft success rates. We also investigated the duration of surgery and operation time, and pain scores in both groups.Materials and Methods: In this retrospective study, we included the patients who were performed endoscopic type 1 tympanoplasty with tragal cartilage graft. Visual evaluation of eardrums and audiologic datas of the patients were performed. The cases with cholesteatoma and/or ossicular chain problem were not included to study. Patients were evaluated in two different groups as LMA and endotracheal tube (ET) group. Preoperatively perforation types and audiological data; intraoperatively operation and surgical times; postoperatively 3th month surgical success, pain scores and audiological results were recorded in each group. And these results were evaluated statistically to compare the differences between LMA and ET group.Results: Ninety-three patients were included in the study and 36 of them underwent endoscopic tympanoplasty with LMA and 57 patients with ET. The surgery time was similar in both groups (p> 0.05), but the operation time was statistically significantly shorter in the LMA group (p 0.05). Graft success rates and hearing gain were higher in the LMA group but not statistically significant.Conclusions: We observed that endoscopic tympanoplasty with LMA or ET had similar surgery time, graft success rate, and pain scores, but total operation time was significantly shorter in the LMA group. As a result, LMA can be considered as a suitable method for endoscopic tympanoplasty.

There is controversy over (1) the relative incidence of sore throat between the face mask (FM) and laryngeal mask airway (LMA), (2) the efficacy of LMA intracuff pressure reduction as a mechanism for minimizing sore throat, and (3) the relative incidence of sore throat with the LMA between males and females. In a randomized double-blind study, the authors compared laryngopharyngeal, neck, and jaw discomfort with the FM and LMA at high and low cuff volumes in males and females. Three hundred adult patients were randomly assigned to three equal-sized groups for airway management: (1) the FM, (2) the LMA with a fully inflated cuff (LMA-High), or (3) the LMA with a semi-inflated cuff (LMA-Low). Anesthesia was administered with propofol, nitrous oxide, oxygen, and isoflurane. In the FM group, a Guedel-type oropharyngeal airway and jaw thrust were used only if necessary. In the LMA groups, cuff inflation was achieved with either 15 or 30 ml for the size 4 (females) and 20 or 40 ml for the size 5 (males). The LMA was removed when the patient was awake. Patients were questioned 18-24 h postoperatively about surgical pain, sore throat, sore neck, sore jaw, dysphonia, and dysphagia, and about whether they were satisfied with their anesthetic. The incidence of sore throat was lower in the FM (8%) than the LMA-High (42%) and LMA-Low (20%) groups (both: P < or = 0.02). The incidence of sore neck was higher for the FM (14%) than the LMA-High group (6%; P = 0.05) but similar to the LMA-Low group (8%). The incidence of sore jaw was higher in the FM (11%) than the LMA-High (3%) and LMA-Low (3%) groups (both: P = 0. 02). There were no differences among groups for surgical pain or dysphonia. The incidence of dysphagia was lower in the FM (1%) than the LMA-High group (11%; P = 0.003), but similar to the LMA-Low group (1%). The incidence of sore throat and dysphagia was lower in the LMA-Low group than the LMA-High group for both males and females (all: P < or = 0.04). There were no differences in discomfort levels between males and females in any group. Two patients from the FM group and one from the LMA-High group were not satisfied with their anesthetic. These complaints were unrelated to postoperative morbidity. The LMA causes more sore throat and dysphagia but less jaw pain than the FM. Sore throat and dysphagia are more common with the LMA if the initial cuff volume is high. There are no differences in discomfort levels between males and females. However, these discomforts do not influence patient satisfaction after LMA or FM anesthesia.

Neurocirculatory responses to intubation with either an endotracheal tube or a laryngeal mask airway in humans

Premature infants are subjected to adverse effects of intubation to benefit from surfactant. We hypothesized that administration of surfactant through a laryngeal mask airway (LMA) is as effective as administration through an endotracheal tube (ETT) and that time and physiologic changes during instrumentation will be less in the LMA group. This study is a randomized, controlled trial using newborn pigs. Lung injury was induced via surfactant washout. Animals were randomized into groups: 1) LMA placed, no surfactant administered (control; n = 8); 2) surfactant via an LMA (LMA group; n = 8); and 3) surfactant via an ETT (ETT group; n = 8). We demonstrated that partial pressure of oxygen in arterial blood (Pao2) levels of the LMA and ETT groups were not statistically different. Time for successful placement of LMA was 19 ± 1 s versus ETT 123 ± 35 s (mean ± SEM); number of attempts for successful LMA placement was 1.1 (1-2) versus ETT 1.9 (1-7) [mean (range)]. Administration of surfactant via an LMA compared with an ETT resulted in similar improvements in oxygenation. Placement of the device required less time and fewer attempts. These data suggest that further study in human neonates is justified. If proven effective, some infants with respiratory distress may be able to receive surfactant while avoiding intubation.

Comparison of the Effect of Laryngeal Mask Airway Versus Endotracheal Tube on Airway Management in Pediatric Patients with Tonsillar Hypertrophy

Providing effective positive pressure ventilation is considered to be the single most important component of successful neonatal resuscitation. Ventilation is frequently initiated manually with bag and face mask (BMV) followed by endotracheal intubation if respiratory depression continues. These techniques may be difficult to perform successfully resulting in prolonged resuscitation or neonatal asphyxia. The laryngeal mask airway (LMA) may achieve initial ventilation and successful resuscitation faster than a bag-mask device or endotracheal intubation. Among newborns requiring positive pressure ventilation for cardio-pulmonary resuscitation, is LMA more effective than BMV or endotracheal intubation for successful resuscitation? When BMV is either insufficient or ineffective, is effective positive pressure ventilation and successful resuscitation achieved faster with the LMA compared to endotracheal intubation? We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL 2017, Issue 1), MEDLINE via PubMed (1966 to 15 February 2017), Embase (1980 to 15 February 2017), and CINAHL (1982 to 15 February 2017). We also searched clinical trials registers, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials. We included randomised and quasi-randomised controlled trials that compared LMA for neonatal resuscitation with either BMV or endotracheal intubation and reported on any outcomes related to neonatal resuscitation specified in this review. Two review authors independently evaluated studies for risk of bias assessments, and extracted data using Cochrane Neonatal criteria. Categorical treatment effects were described as relative risks and continuous treatment effects were described as the mean difference, with 95% confidence intervals (95% CI) of estimates. We included seven trials that involved a total of 794 infants. Five studies compared LMA with BMV and three studies compared LMA with endotracheal intubation. We added six new studies for this update (754 infants).LMA was associated with less need for endotracheal intubation than BMV (typical risk ratio (RR) 0.24, 95% CI 0.12 to 0.47 and typical risk difference (RD) -0.14, 95% CI -0.14 to -0.06; 5 studies, 661 infants; moderate-quality evidence) and shorter ventilation time (mean difference (MD) -18.90 seconds, 95% CI -24.35 to -13.44; 4 studies, 610 infants). Babies resuscitated with LMA were less likely to require admission to neonatal intensive care unit (NICU) (typical RR 0.60, 95% CI 0.40 to 0.90 and typical RD -0.18, 95% CI -0.31 to -0.04; 2 studies,191 infants; moderate-quality evidence). There was no difference in deaths or hypoxic ischaemic encephalopathy (HIE) events.Compared to endotracheal intubation, there were no clinically significant differences in insertion time or failure to correctly insert the device (typical RR 0.95, 95% CI 0.17 to 5.42; 3 studies, 158 infants; very low-quality evidence). There was no difference in deaths or HIE events. LMA can achieve effective ventilation during neonatal resuscitation in a time frame consistent with current neonatal resuscitation guidelines. Compared to BMV, LMA is more effective in terms of shorter resuscitation and ventilation times, and less need for endotracheal intubation (low- to moderate-quality evidence). However, in trials comparing LMA with BMV, over 80% of infants in both trial arms responded to the allocated intervention. In studies that allowed LMA rescue of infants failing with BMV, it was possible to avoid intubation in the majority. It is important that the clinical community resorts to the use of LMA more proactively to provide effective ventilation when newborn is not responding to BMV before attempting intubation or initiating chest compressions.LMA was found to offer comparable efficacy to endotracheal intubation (very low- to low-quality evidence). It therefore offers an alternate airway device when attempts at inserting endotracheal intubation are unsuccessful during resuscitation.Most studies enrolled infants with birth weight over 1500 g or 34 or more weeks' gestation. As such, there is lack of evidence to support LMA use in more premature infants.

A prototype armoured laryngeal mask airway (LMA) was compared with tracheal intubation (ETT) for anaesthesia for adenotonsillectomy. Fifty-five children were randomised into the LMA group and 54 into the ETT group. During insertion of the LMA, peripheral oxyhaemoglobin desaturation (SpO2) < 94% occurred in ten patients (18.2%) and in seven patients (13%) during tracheal intubation (NS). After opening the Boyle-Davis gag, airway obstruction occurred in ten patients (18.2%) in the LMA group and in three patients (6%) in the ETT group (P = 0.07). In five patients (9%) the LMA was abandoned in favour of tracheal intubation. In all others (91%), when the need for adequate depth of anaesthesia was realized, a satisfactory airway was achieved more rapidly than with tracheal intubation (P < 0.001), and maintained throughout surgery. Manually assisted ventilation was required in all patients in the ETT group, mean duration 373 +/- 385 sec, and in 26 patients (52%) in the LMA group, mean duration 134 +/- 110 sec, P < 0.001. Mean end-tidal CO2 (PetCO2) was 45.5 +/- 6.21 mmHg in the ETT group and 46.6 +/- 6.09 in the LMA group (NS). The LMA did not limit surgical access. Heart rate, MAP and blood loss in the LMA group were 110 +/- 21, 74 +/- 9 mmHg and 1.92 +/- 1.22 ml.kg-1 respectively, compared with 143 +/- 13 (P < 0.001), 85 +/- 12 mmHg (P < 0.001) and 2.62 +/- 1.36 ml.kg-1 (P < 0.05) with tracheal intubation. Fibreoptic laryngoscopy at the end of surgery in 19 patients in the LMA group revealed no blood in the larynx.(ABSTRACT TRUNCATED AT 250 WORDS)

The cuffed oropharyngeal airway (COPA) is a modified Guedel airway with a cuff at its distal end and a standard 15 mm connector at its proximal end. This study was performed to determine if the COPA would offer any advantage over the laryngeal mask airway (LMA). Eighty ASA class I to II adult patients scheduled for short elective procedures (less than 1 h) were randomly allocated into two groups. All patients were given atropine 0.01 mg/kg, fentanyl 2 micrograms/kg and propofol 2 mg/kg intravenously for induction of anesthesia. The COPA or LMA was inserted following the loss of eyelash reflex. If the jaw was not relaxed enough for insertion of a COPA or LMA, succinylcholine 1 mg/kg was given to facilitate the insertion. When correctly positioned, the cuff was immediately inflated with an appropriate volume. Gentle positive pressure ventilation was applied before spontaneous breathing resumed. Capnography was used to assess the patency of the airway. Anesthesia was maintained with isoflurane-N2O-O2 until the end of surgery. The success rate, vital signs, and adverse events were evaluated and compared. The success rate in the LMA group (95%) was higher than the COPA group (85%). The increase in circulatory response after the LMA insertion was greater than that after the COPA insertion (P < 0.05). Nine patients (22.5%) in the LMA group needed succinylcholine to facilitate insertion compared with only two patients (5%) in the COPA group. Additional manipulation was frequently (57.5%) needed after inserting the COPA to maintain the patency of the airways, but none needed so in the LMA group. Two patients had laryngospasms upon removal of the LMA, but none had laryngospasm in the COPA group. The incidence of sore throat in the LMA group was higher than in the COPA group (18% vs. 10%). We demonstrated that the COPA could be easily inserted without the need of muscle relaxants in most patients. But the COPA needed airway intervention to provide an effective airway in most patients. Compared with the LMA, the COPA caused less stimulation than the LMA.

This Month in ANESTHESIOLOGY

Objective To compare the performance of the streamlined pharynx airway liner (SLIPA~(TM)) with the conventional laryngeal mask airway(LMA) for airway management in minor surgery under general anesthesia. Methods Sixty fasted adult patients with ASA status Ⅰ～Ⅱ were randomly designed to establish SLIPA~(TM) airway (SLIPA~(TM) group) or LMA airway(LMA group) for airway management during anesthesia. Article airway handling, pharynx sealing, ventilation maintenance and adverse reactions with SLIPA~(TM) group and LMA group were assessed. Results SLIPA~(TM) had comparable total rate of successful insertion and airway placement difficulty to LMA(P>0.05). Maximum seal pressure was (22±5) cm H_20 and (24±6) cm H_2O in SLIPA~(TM) group and LMA group (P>0.05), respectively. A leak was noticed in 20% and 16.7% of patiemts in LMA group when patients' lungs were ventilated using intermittent positive pressure ventilation mode after airway mask placment and during surgery, and 3.3% and 0 in SLIPA~(TM) group (P<0.05). The incidence of sore trauma was similar in both groups. Conclusion SLIPA~(TM) is an acceptable and alternative method for LMA, exerting similar clinical performance with easier placement, less sore trauma and more stable IPPV during minor surgery. Key words: SLIPA~(TM); LMA; Airway management