Laryngeal Mask Airway Ventilation Research Articles

Application of placing the anterior end of endotracheal tube at the glottis in laryngeal mask airway positive ventilation during general anesthesia: A prospective, randomized, controlled trial.

Glottic contraction and closure causes ventilation obstruction and laryngeal mask airway (LMA) leakage during positive pressure ventilation using LMA. This study aimed to assess the effect of placing the anterior end of the endotracheal tube (ET) at the glottis through the LMA ventilation conduit on treating LMA leakage following glottic contraction and closure. In this prospective, randomized, controlled trial, patients with non-minor surgery using LMA ventilation were randomly allocated to the i-gel group (group L) and the i-gel combined with ET group (group LE). The tip of ET was placed 2 cm under glottis guided by fiberoptic bronchoscope through i-gel ventilation conduit in group LE. The perioperative incidence of i-gel leakage, the changes of systolic blood pressure (SBP) and heart rate (HR) following artificial airway insertion, and adverse events were recorded. Perioperative i-gel leakage was observed in 7 of 48 patients (14.6%) in group L and 1 of 49 patients (2.0%) in group LE. There was significant difference in the incidence of leakage between the 2 groups (P = .031). SBP and HR after ET insertion in group LE increased significantly compared to those in group L (P < .05/5). The values of both SBP and HR after ET insertion did not exceed the basic values in group LE (P > .05/4). There were no significant differences in the incidence and severity of postoperative sore pain and hoarseness, cough during i-gel and ET removal between the 2 groups (P > .05). Placing the anterior end of ET at the glottis reduced LMA air leakage related to glottic contraction and closure in non-minor surgery. The ET placing had low stress response and did not significantly increase postoperative complications.

What we have learned from a patient with partial tracheal rupture caused by penetrating neck injuries: a case report

BackgroundAirway management of patients with direct airway trauma caused by penetrating neck injuries is always challenging. When a failed airway occurs and surgery access is difficult, it is crucial to find the optimal approach to save the life. We propose the concept “Cannot intubate, Cannot oxygenate, Difficult surgery access” to describe this emergency scenario.Case presentationWe report a case of a 24-year-old woman who presented with partial tracheal rupture and pneumothorax caused by a knife stab injury to the neck. A "double setup" strategy, simultaneous preparation for orotracheal intubation and tracheotomy, was carried out before rapid sequence induction. A tracheotomy under local anesthesia or an awake intubation was not preferred in consideration that the patient had a high risk of being uncooperative owing to existing mental disease and potential smothering sensation during operation. During rapid sequence intubation, distal part of the tube penetrates the tear and creates a false lumen outside the trachea then a failed airway subsequently occurred. Rescue tracheotomy was successfully performed by an otolaryngology surgeon, with the help of limited ventilation using sequential bag–mask and laryngeal mask airway ventilation provided by an anesthesiologist, without severe sequelae.ConclusionsThe endotracheal tube have a risk of penetrating the tear outside the trachea in patient with partial tracheal rupture during orotracheal intubation, and once it occurs, proceeding directly to an emergency invasive airway access with optimizing oxygenation throughout procedure might increase the chance of success in rescuing the airway.

Laryngeal mask ventilation with chest compression during neonatal resuscitation: randomized, non-inferiority trial in lambs.

Background:Effective positive pressure ventilation is a critical factor in newborn resuscitation. Neonatal endotracheal intubation (ETT) needs considerable training and experience, which poses a human factor challenge. Laryngeal mask airway (LMA) ventilation can be a secure and viable alternative during the initial stages of newborn resuscitation. However, there is limited evidence for its use during chest compression (CC).Methods:Seventeen lambs were randomized into LMA or ETT ventilation post cord occlusion induced cardiac arrest. After 5 minutes of cardiac arrest, resuscitation was initiated as per NRP recommendations. Ventilation, oxygenation, systemic and pulmonary hemodynamic parameters were recorded till return of spontaneous circulation (ROSC) or 20 minutes.Results:Baseline characteristics were similar between the groups. The incidence of ROSC was 75% (6/8) in the LMA group and 56% (5/9) in the ETT group (p = 0.74). The median (IQR) time to achieve ROSC was 6.85 min (6 min – 9.1 min) in the LMA group and 7.50 min (5.33 min – 18 min) in the ETT group (p = 0.65).Conclusion:LMA ventilation during CC is feasible and non-inferior to ETT in this model.

Efficacy of Low-Dose Suxamethonium in Reducing Induction Dose of Propofol for Laryngeal Mask Airway Insertion in Nigerian Adults

Background: Propofol is commonly used as a sole induction agent during laryngeal mask airway (LMA) insertion, and additional doses are often required with systemic consequences. Objective: Our study evaluated the effect of 0.1 mg/kg suxamethonium on the dose of induction of propofol when used during insertion of LMA. Methodology: Eighty patients aged between 18 and 60 years were included in this prospective study. Patients undergoing elective procedures under general anaesthesia with LMA and spontaneous ventilation were randomized into two groups. Patients in both groups were induced with an initial dose of 2.5 mg/kg of propofol; the control group (group P) and the second group (group S) received 5 ml of normal saline and 0.1 mg/kg of suxamethonium made up to 5 ml, respectively. The need for additional doses of propofol following insertion of LMA was then assessed based on insertion conditions (ease of insertion, severity of airway response in terms of coughing, gagging, laryngospasm, and patient movement). The total dose of propofol required before successful insertion was recorded, as well as the incidence and duration of apnea post-induction. The pulse rate (PR), systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) were assessed at 0, 1, 3 and 5 min after insertion of LMA for each group. Results: The total dose of propofol required for successful LMA insertion was significantly lower in group S (2.82 ± 0.39 mg/kg) compared to group P (3.13 ± 0.49 mg/kg), P = 0.002. Haemodynamic parameters (SBP, DBP, MAP, PR, and SpO2) were well-controlled post-LMA insertion and were comparable between the two groups. Furthermore, no incidence of hypotension or bradycardia requiring intervention was observed at different time intervals, throughout the study period, in both groups. Conclusion: The dose of propofol is lesser when low-dose suxamethonium (0.1 mg/kg) precedes its use for induction during LMA insertion, and there is a reduction in the duration of apnea; however, it causes a higher apnea incidence. Vital signs were similar in the two study groups.

Various Uses of Laryngeal Mask Airway during Tracheal Surgery.

The use of laryngeal mask airway (LMA) ventilation in surgeries to be performed in upper tracheal stenosis has been reported in the case series. However, there is no generally accepted standardized approach for the use of LMA. In this study, LMA usage areas and advantages of trachea surgery were examined. The records of 21 patients who underwent tracheal surgery using LMA ventilation between March 2016 and May 2020 were evaluated retrospectively. The patient data were analyzed according to age, gender, mean follow-up time, surgical indication, mean tracheal resection length, anastomosis duration, mean oxygen saturation, mean end-tidal CO2 levels, and postoperative complications. Four patients were female and 17 were male, their median age was 43 (11-72 range) and the mean follow-up time was 17.6 months. The most common surgical indication was postintubation tracheal stenosis. The mean tracheal resection length was 26.6 mm and the mean anastomosis duration was 11.3 minutes. The mean pulse oximetry and mean end-tidal CO2 during laryngeal mask ventilation was 97.6% ± 2.1 and 38.1 ± 2.8 mm Hg, respectively. Postoperative complications were higher in patients with comorbidities. LMA-assisted tracheal surgery is a method that can be used safely as a standard technique in the surgery of benign and malignant diseases of both the upper and lower airway performed on pediatric patients, patients with tracheostomy, and suitable patients with tracheoesophageal fistula.

Bag-Valve-Mask versus Laryngeal Mask Airway Ventilation in Cardiopulmonary Resuscitation with Continuous Compressions: A Simulation Study.

The 2017 International Liaison Committee on Resuscitation (ILCOR) guideline recommends that Emergency Medical Service (EMS) providers can perform cardiopulmonary resuscitation (CPR) with synchronous or asynchronous ventilation until an advanced airway has been placed. In the current literature, limited data on CPR performed with continuous compressions and asynchronous ventilation with bag-valve-mask (BVM) are available. In this study, researchers aimed to compare the effectiveness of asynchronous BVM and laryngeal mask airway (LMA) ventilation during CPR with continuous chest compressions. Emergency medicine residents and interns were included in the study. The participants were randomly assigned to resuscitation teams with two rescuers. The cross-over simulation study was conducted on two CPR scenarios: asynchronous ventilation via BVM during a continuous chest compression and asynchronous ventilation via LMA during a continuous chest compression in cardiac arrest patient with asystole. The primary endpoints were the ventilation-related measurements. A total of 92 volunteers were included in the study and 46 CPRs were performed in each group. The mean rate of ventilations of the LMA group was significantly higher than that of the BVM group (13.7 [11.7-15.7] versus 8.9 [7.5-10.3] breaths/minute; P <.001). The mean volume of ventilations of the LMA group was significantly higher than that of the BVM group (358.4 [342.3-374.4] ml versus 321.5 [303.9-339.0] ml; P = .002). The mean minute ventilation volume of the LMA group was significantly higher than that of the BVM group (4.88 [4.15-5.61] versus 2.99 [2.41-3.57] L/minute; P <.001). Ventilations exceeding the maximum volume limit occurred in two (4.3%) CPRs in the BVM group and in 11 (23.9%) CPRs in the LMA group (P = .008). The results of this study show that asynchronous BVM ventilation with continuous chest compressions is a reliable and effective strategy during CPR under simulation conditions. The clinical impact of these findings in actual cardiac arrest patients should be evaluated with further studies at real-life scenes.

Laryngeal Mask Ventilation during Tracheostomy Improves Intraoperative Hemodynamic Stability in Patients Undergoing Total Laryngectomy

Abstract Background and objectives: Laryngectomy with extensive extirpational neck dissection is still the treatment of choice for patients with advanced laryngeal cancer. During the initial part of laryngectomy – tracheostomy, there is a significant upper airway obstruction, caused by the cancer process itself and worsened by surgical pressure and manipulation during creation of tracheostomy. This study aims to make comparative assessment of the patient’s hemodynamic parameters, operated using three of the most popular approaches during tracheostomy: local anesthesia with preserved spontaneous ventilation; general anesthesia with ventilation by endotracheal intubation and general anesthesia with ventilation by laryngeal mask airway. Methods: A prospective cohort study was conducted in a tertiary referral center. Sixty patients with advanced laryngeal cancer appointed for total laryngectomy, were enrolled in the study. They were randomly assigned into three groups, according to the ventilation method used during the tracheostomy. Results: Patients who underwent tracheostomy under local anesthesia displayed statistically the highest levels of SAP, DAP, MAP and heart rate intraoperatively. The group of patients who underwent tracheostomy with endotracheal intubation, also displayed significantly higher levels of hemodynamic parameters during the procedure compared with the group with laryngeal mask airway ventilation, despite the fact that both groups were under general anesthesia. Conclusions: To our knowledge, this is the first study to demonstrate that laryngeal mask ventilation during tracheostomy improves intraoperative hemodynamic stability in patients undergoing total laryngectomy compared to endotracheal intubation.

Feasibility of supraglottic tracheal tube ventilation during painless fiberbronchoscopy

Objective: To evaluate the feasibility and safety of supraglottic tracheal tube ventilation by comparing with modified laryngeal mask airway ventilation during painless fiberbronchoscopy. Methods: This was a prospective study. Twenty-eight patients undergoing painless fiberbronchoscopy in Hangzhou First People's Hospital were randomly divided into 2 groups(n=14): supraglottic tracheal tube ventilation(group A) and modified laryngeal mask airway(group B). MAP, HR, SpO(2), P(ET)CO(2) and BIS were recorded after entering the operating room(T(0)), after anesthesia induction(T(1)), immediately after inserting laryngeal mask airway or tracheal tube(T(2)), fiberbronchoscopy inserting(T(3)), at the end of the operation(T(4)), and at the recovery of patients' consciousness(T(5)). The arterial carbon dioxide partial pressure(PaCO(2)), the time spent in successful positioning of the tube, the endoscope indwelling duration, operative time, tube drawing time, patients' awakening time, satisfaction of operators, adverse events during anesthesia, the numbers of bucking or body moving were also recorded.The dose of propofol and remifentanil were also statisticed. Results: P(ET)CO(2) in group A at T(0), T(1), T(2), T(3), T(4), T(5) were (36.9±4.1), (36.3±4.7), (38.1±5.6), (40.4±4.0), (48.8±7.7), (45.3±7.6) mmHg, P(ET)CO(2) in group B were (38.6±4.4), (37.8±5.6), (37.8±5.4), (37.4±6.7), (43.3±12.2), (43.5±8.0) mmHg, at the end of operation, the P(ET)CO(2) at T(4) and T(5) were significantly higher than at T(0) in group A and group B (F=14.582, 12.651, all P<0.05). The PaCO(2) in group A was (62.0±4.7) mmHg , which was significantly higher than group B at the end of operation[(51.9±4.2) mmHg, t=2.432, P<0.05]. The time spent successfully positioning the insertion in group A and group B were (17.6±7.5), (29.8±13.6)s, the endoscope indwelling duration were(0.8±0.1), (1.4±0.3)min, and the operation time were(32.3±4.3), (46.8±4.8)min, there were significantly difference between group A and group B(t=2.670, 2.214, 2.166, all P<0.05). There were no significantly difference of the numbers of bucking or body moving , the satisfaction of operators and patients, and adverse events (all P>0.05). Conclusion: Supraglottic tracheal tube ventilation for painless fiberbronchoscopy is a safe and effective procedure.

Safety and efficacy of laryngeal mask airway ventilation in obese patients with airway stenosis.

To assess the efficacy of laryngeal mask airway (LMA) ventilation in obese patients with airway stenosis. A retrospective chart review was conducted in an academic practice in a tertiary care center. We retrospectively reviewed our experience using LMA ventilation in obese patients with airway stenosis. Lowest intraoperative O2 saturation and maximum-end tidal carbon dioxide (CO2 ) levels were recorded. Complications including intubation, unplanned admission, re-admission, postoperative pain, dysphonia, oral trauma, pneumothorax, pneumomediastinum, and tracheostomy were recorded. Fourteen bronchoscopies with laser incisions and dilation were performed in patients with airway stenosis exclusively using LMA ventilation. Thirteen of 14 procedures were performed on patients who had body mass index (BMI) > 30 kg/m2 . Mean BMI was noted to be 38 kg/m2 (range 25-54). All patients underwent successful laser incisions and dilation via LMA anesthesia without major or minor adverse events. The mean lowest O2 saturation level was noted to be 92%; the mean highest CO2 level was noted to be 56 mm Hg; and no patients required endotracheal intubation. In this small series of obese patients with airway stenosis, LMA anesthesia was effectively used without major or minor complications. 4. Laryngoscope, 127:2582-2584, 2017.

A growing animal model for neonatal repair of large diaphragmatic defects to evaluate patch function and outcome.

ObjectivesWe aimed to develop a more representative model for neonatal congenital diaphragmatic hernia repair in a large animal model, by creating a large defect in a fast-growing pup, using functional pulmonary and diaphragmatic read outs.BackgroundGrafts are increasingly used to repair congenital diaphragmatic hernia with the risk of local complications. Growing animal models have been used to test novel materials.Methods6-week-old rabbits underwent fiberoptic intubation, left subcostal laparotomy and hemi-diaphragmatic excision (either nearly complete (n = 13) or 3*3cm (n = 9)) and primary closure (Gore-Tex patch). Survival was further increased by moving to laryngeal mask airway ventilation (n = 15). Sham operated animals were used as controls (n = 6). Survivors (90 days) underwent chest X-Ray (scoliosis), measurements of maximum transdiaphragmatic pressure and breathing pattern (tidal volume, Pdi). Rates of herniation, lung histology and right hemi-diaphragmatic fiber cross-sectional area was measured.ResultsRabbits surviving 90 days doubled their weight. Only one (8%) with a complete defect survived to 90 days. In the 3*3cm defect group all survived to 48 hours, however seven (78%) died later (16–49 days) from respiratory failure secondary to tracheal stricture formation. Use of a laryngeal mask airway doubled 90-day survival, one pup displaying herniation (17%). Cobb angel measurements, breathing pattern, and lung histology were comparable to sham. Under exertion, sham animals increased their maximum transdiaphragmatic pressure 134% compared to a 71% increase in patched animals (p<0.05). Patched animals had a compensatory increase in their right hemi-diaphragmatic fiber cross-sectional area (p<0.0001).ConclusionsA primarily patched 3*3cm defect in growing rabbits, under laryngeal mask airway ventilation, enables adequate survival with normal lung function and reduced maximum transdiaphragmatic pressure compared to controls.

Case Report: Post-Operative Airway Obstruction in A Patient with Reinke’s Edema

Here we present the case of a 64 year old female with a history of neck radiation and Reinke’s edema that experienced unexpected respiratory failure after a sedation anesthetic. After the case terminated, the patient was noted to be hypoventilating and stridorous. Mask ventilation, laryngeal mask airway ventilation, and direct laryngoscopy failed. The patient was intubated with video laryngoscopy. Reinke's edema, a benign lesion characterized by swelling of the vocal folds, was thought to contribute to the difficulty in ventilating and intubating this patient. We present a discussion of Reinke’s edema and its potential relevance to the practice of anesthesia.

Use of capnographs to assess quality of pediatric ventilation with 3 different airway modalities

ObjectivesPrehospital pediatric airway management is difficult and controversial. Options include bag-mask ventilation (BMV), endotracheal tube (ETT), and laryngeal mask airway (LMA). Emergency Medical Services personnel report difficulty assessing adequacy of BMV during transport. Capnography, and capnograph tracings in particular, provide a measure of real-time ventilation currently used in prehospital medicine but have not been well studied in pediatric patients or with BMV. Our objective was to compare pediatric capnographs created with 3 airway modalities. MethodsThis was a prospective study of pediatric patients requiring ETT or LMA ventilation during elective surgical procedures. Data were collected during BMV using 2 bag types (flow-inflating and self-inflating). The ETT or LMA was placed and ventilation with each bag type repeated. Ten- to 14-second capnographs were reviewed by 2 blinded anesthesiologists who were asked to assess ventilation and identify the airway and bag type used. Descriptive statistics, κ, and risk ratios were calculated. ResultsTwenty-nine patients were enrolled. Median age was 4.4 years (2 months to 16.8 years). One hundred sixteen capnographs were reviewed. Reviewers were unable to differentiate between airway modalities and agreed on adequacy of ventilation 77% of the time (κ = 0.6, P < .001). Bag-mask ventilation was rated inadequate more frequently than ETT or LMA ventilation. There were no difference between ETT and LMA ventilation and no difference between the 2 bag types. ConclusionCapnographs are generated during BMV and are virtually identical to those produced with ETT or LMA ventilation. Attention to capnographs could improve outcomes during emergency treatment and transport of critically ill pediatric patients requiring ventilation with any of these airway modalities.

The uses of laryngeal mask airway ProSeal™ and endobronchial blocker for one lung anesthesia.

The use of an endobronchial blocker in conjunction with a supraglottic device in elective thoracic cases has never been studied. The aim of this study was to report the success rate and time to placement of the endobronchial blocker in anaesthetized patients with a laryngeal mask airway (LMA)-ProSeal™ in place. This was a single-center, prospective, descriptive pilot study that enrolled 30 patients aged 18-75 years, with ASA I-III, who underwent elective thoracotomy or video-assisted thoracoscopy. We collected data on time to placement of the endobronchial blocker into the selected bronchus, time consumed for final blocker positioning and inflation, lung deflation score at chest opening, and postoperative airway complications. One patient was excluded because of high peak airway pressure during LMA ventilation. The time required for blocker placement in the right main bronchus was shorter [mean 160 (78-480) s] compared with that for the left main bronchus [225 (117-420) s]. The blocker was successfully placed on the first attempt in 25 patients. Lung deflation score graded by the surgeon was 8/10 (median). Minor postoperative airway complications, such as sore throat (28.6 %) and hoarseness of voice (17.9 %), were reported. The use of LMA-ProSeal™ in conjunction with the COOPDECH Endobronchial Blocker Tube may be considered an alternative one-lung ventilation technique in selected cases. However, success rates and time required for placement of the blocker seem dependent on the operator's skill. Although postoperative sore throat and hoarseness of voice were reported, these improved in 24 h.

Multicenter randomized controlled clinical trial of the efficacy of laryngeal mask airway during neonatal resuscitation

Objective To determine the feasibility,efficacy and safety of the laryngeal mask airway(LMA) ventilation in neonatal resuscitation.Methods Newborns weighing ≥ 2 000 g or delivered at ≥ 34 weeks gestation,who needed positive pressure ventilation,born between April 1,2012 and November 30,2013,in six tertiary hospitals of Guangdong Province,China,were enrolled.According to the parity of their birth date,neonates with a heart rate ≥ 60 beats per minute after initial resuscitation within 30 s,were randomly divided into laryngeal mask ventilation group 1 (LMA1 group,238 cases) and bag-mask ventilation group (BMV group,274 cases).Neonates with a heart rate ＜60 beats per minute were randomly divided into laryngeal mask ventilation group 2 (LMA2 group,85 cases) and endotracheal intubation ventilation group (ETT group,71 cases).The efficacy and adverse events among the groups were compared with t test,rank-sum test and x2 test.Results In the LMA 1 group,the successful insertion rate of the LMA at the first attempt was 95.3％ (227/238) and the insertion time was (7.0±0.7) s.Compared with the BMV group,the LMA1 group had a higher successful resuscitation rate [96.6％ (230/238) vs 79.6％ (218/274),x2=33.96,P=0.00] and shorter response time [(14.6±2.5) s vs (18.3±5.3) s,t=-9.79,P=0.00] and ventilation time [36.4 s (29.7-40.2 s) vs 50.2 s (40.3-63.3 s),Z=12.23,P=0.00].Compared with the ETT group,insertion time [(6.8±0.7) s vs (8.0±0.9) s,t=-9.45,P=0.00] and ventilation time [164.6 s (154.3-174.0 s) vs 173.4 s (162.3-185.2 s),Z=3.16,P=0.00] were shorter in the LMA2 group (all P＜0.05).There were no significant differences in heart rate before resuscitation and 1,2,3 and 5 min after fetal head delivery between the LMA1 and BMV groups (all P＞0.05),but transcutaneous oxygen saturation (SpO2) at 1,2,3 and 5 min after fetal head delivery was higher in the LMA1 group [(51.5±6.3) ％ vs (48.3±7.9) ％,t=2.45; (72.1 ±3.9) ％ vs (70.1 ±4.7) ％,t=2.62; (76.2±3.4) ％ vs (74.3±5.1) ％,t=3.04; (87.7±9.4) ％ vs (84.5±3.4) ％,t=5.31; all P＜0.05].There were no significant differences between the LMA2 and ETT groups in heart rate and SpO2 before and after resuscitation (all P＞0.05).Blood gas,lactic acid,and glucose levels before and after resuscitation showed no significant differences between the LMA1 and BMV groups,neither between the LMA2 and ETT groups (all P＞0.05).There were no significant differences in the incidence of adverse events between the LMA1 and BMV groups [3.4％ (8/238) vs 5.1％ (14/274),x2=1.02,P=0.31],and between the LMA2 and ETT groups [3.5％ (3/85) vs 2.8％ (2/71),x2=0.00,P=1.00].Conclusions LMA ventilation is safe,effective and easy to implement for the resuscitation of neonates with a gestational age ≥ 34 weeks or birth weight ≥ 2 000 g. Key words: Positive-pressure respiration; Laryngeal masks; Resuscitation; Infant, newborn; Randomized controlled trial

Case control study of laryngeal mask airway versus endotracheal intubation in neonatal resuscitation

Objective To study the feasibility,efficacy and safety of u tilizing the laryngeal mask airway (LMA) ventilation compared with the endotracheal intubation ( ET ) in neonatal resuscitation for moderate and severe asphyxiated neonates.Methods Neonates requiring positive pressure ventilation with heartrate ＜60 beats/min were collected and grouped quasi-randomizedly into LMA(36 cases) or ET(32 cases)ventilation.Differences of resuscitation effect,inserting time,successful once insertion rate and adverse reactions between the two groups were observed and compared.Results ( 1 ) No significant difference was observed in Apgar scores at 1 min and 5 min between the two groups ( P＞0.05 ).(2) Success rate of once insertion was 94.4％ with average inserting time ( 7.58±1.16 ) s for LMP group,while it was 90.6％ and ( 7.89 ± 1.52) s for ET group.( 3 ) Successful resuscitation rate of LMA group ( 86.11％ ) was slightly lower than ET group (96.88％ ),but there was no statistical difference (P＞0.05).(4) Mean response time of LMA group [ (34.06 ± 10.56) s] was slightly lower than that of ET group [ (41.38 ±27.19) s],also ventilation time of LMA group [( 137.19 ±80.14) s] was slightly lower than that of ET group [ ( 171.09±84.28 ) s ],but neither showed statistical difference ( P＞0.05 ).(5) Adverse reactions were found in LMA group including nausea( 2 cases )and abdominal distention (1 cases),while there were laryngeal edema( 1 cases),pneumothorax(2 cases),respiratory tract bleeding( 1 cases) in ET group.Conclusion The LMA ventilation is much easier to operate,with its effect no less than that of ET ventilation on resuscitation for moderate and severe asphyxiated cases,even it seems more safe.LMA ventilation can be a good substitute for ET ventilation,especially for those medical staffs who are unfamiliar with ET operation and primary hospital doctors in case of emergency. Key words: Asphyxia ; Neonate ; Resuscitation ; Positive pressure ventilation ; Laryngeal mask airway ; Endotracheal intubation ;

A prospective evaluation of the efficacy of the laryngeal mask airway during neonatal resuscitation

Objective To study the feasibility, efficacy and safety of using the laryngeal mask airway (LMA) in neonatal resuscitation. Methods In total, 369 neonates (gestational age ≥34 weeks, expected birth weight ≥2.0 kg) requiring positive pressure ventilation at birth were quasi-randomised to resuscitation by LMA (205 neonates) or bag-mask ventilation (164 neonates). Results (1) Successful resuscitation rate was higher with the LMA compared with bag-mask ventilation ( P < 0.001) and the total ventilation time was shorter with the LMA than with bag-mask ventilation ( P < 0.001). Seven of nine neonates with an Apgar score of 2 or 3 at 1 min after birth were successfully resuscitated in the LMA group, while in the BMV group all six neonates with an Apgar score of 2 or 3 at 1 min required tracheal intubation and ventilation. In neonates with an Apgar score of 4 or 5 at 1 min after birth, successful resuscitation rate with the LMA was higher than with bag-mask ventilation ( P < 0.01). (2) Successful insertion rate of the LMA at the first attempt was 98.5% and the insertion time was 7.8 s ± 2.2 s. There were few adverse events (vomiting and aspiration) in the LMA group. Conclusion The LMA is safe, effective and easy to implement for the resuscitation of neonates with a gestational age of 34 or, more weeks.

Target controlled infusion of Propofol with Remifentanil or Sufentanil for anesthesia with la-ryngeal mask airway ventilation

Objective To evaluate the influence of Remifentanil and Sufentanil on effect of Propofol anesthesia with laryngeal mask airway ventilation. Methods Sixty patients scheduled for elective surgery were randomly divided into propofol group ( group P, n=20 ), propofol with remifentanil group ( group PR, n=20 ) and propofol with sufentanil group ( group PS, n=20 ) .The patients were anesthetized with target controlled infusion of Propofol and RemifentaniK 4 ng/ml) or Sufentanil ( 0.5 ng/ml ).The initial target plasma concentration of Propofol was 2 μ g/ml, and increased step by step until loss of consciousness.The hemodynamic changes and the dosage of Propofol and recovery of anesthesia were observed in all patients.Results Blood pressure was significantly lower in all groups,and HR decreased in PR group after induction of anesthesia(P<0.05 ).Systolic and diastolic blood pressure increased significantly after laryngeal mask airway insertion in group P.The dosage of Propofol required for maintenance of anesthesia in group PR and group PS were reduced by 32.7% and 35.5% respectively.ET-CO2 by spontaneously breathing was higher in the PS group than in group P and group PR when the patients opened their eyes.The times from drug withdrawal to ET-C02 drop to 45mmHg by spontaneously breathing were longer in the PS group than in group P and group PR.Conclusions Remifentanil and sufentanil can reduce significantly the dosage of propofol for anesthesia with laryngeal mask airway ventilation, inhibit the hemodynamic responses to laryngeal mask airway insertion.But the times of laryngeal mask airway extubation could be prolonged by sufentanil during the revitalization of anesthesia. Key words: Propofol; Remifentanil; Sufentanil; Target controlled infusion; Laryngeal mask airway

The Use of a Laryngeal Mask Airway After a Prolonged Suspension Laryngoscopy to Preserve a Vocal Cord Fat Graft

A 62-yr-old man presented for a microdirect laryngoscopy and vocal cord fat grafting under jet ventilation. After a prolonged laryngoscopy, the patient developed hypercapnea and upper airway obstruction secondary to traumatic epiglottitis. The placement of a laryngeal mask airway provided ventilation and allowed for direct visualization of the patient's inflamed epiglottis without disruption of the patient's fat graft. Because of its placement above the cords and its effectiveness in providing adequate ventilation, we propose intermittent laryngeal mask airway ventilation as a bridge, in lieu of endotracheal intubation, in microdirect laryngoscopy cases in which ventilation during emergence may be difficult and the insertion of an endotracheal tube would disrupt the surgical procedure.

Impossible Mask Ventilation

Impossible Mask Ventilation

Feasibility of Laryngeal Mask Airway Use by Prehospital Personnel in Simulated Pediatric Respiratory Arrest

Introduction. Pediatric respiratory arrest is a technically challenging scenario infrequently faced by prehospital providers. Prehospital endotracheal intubation (ETI) is a complex procedure, andone study showed that it may result in worse neurological outcome in these patients. Alternatives to ETI include bag-valve-mask (BVM) ventilation andthe laryngeal mask airway (LMA). Although the LMA has been used successfully for pediatric resuscitation in the hospital setting, there is no data describing its use in the prehospital setting. Hypothesis. Prehospital providers can successfully place andventilate the pediatric LMA in a simulated pediatric respiratory arrest. Methods. Paramedic students received a 1-hour training session covering the use of the pediatric LMA. Subjects performed airway management of a simulator manikin using both the LMA andthe BVM. Rate of successful LMA placement, time to first ventilation, tidal volume by weight, andventilations per minute were recorded. A generalized estimating equation analysis was completed to determine the effects of time andventilation technique. Results. All 13 subjects (100%) successfully ventilated the mannequin with both techniques. The median number of attempts required to successfully place the LMA was one. Median time from the start of the scenario to BVM ventilation was 4 seconds (IQR 3, 5), andthe median for LMA ventilation was 30 seconds (IQR 25, 52). Tidal volumes were significantly greater with BVM ventilation (5.07 mL/kg [IQR 4.47, 5.43]) than with LMA ventilation (2.88 mL/kg [IQR 2.17, 4.04]). An obvious air leak was present in all LMA cases, potentially resulting in reduced tidal volume delivery. Excessive ventilatory rates were noted in both BVM (42 ventilations per minute [IQR 33, 46]) andLMA (37 ventilations per minute [IQR 31, 39]) groups. Conclusions. Prehospital providers were able to place andventilate a simulated pediatric respiratory arrest patient using the LMA after a brief educational intervention. Obvious air leakage was noted when ventilating with the LMA andlikely represents one technical limitation of using a simulator.