Predictors of Laryngospasm During 276,832 Episodes of Pediatric Procedural Sedation.

STUDY OBJECTIVE: Laryngospasm is a rare but potentially life-threatening complication of sedation. The objective of this study was to perform a predictor analysis of biologically plausible predictors and the interventions and outcomes associated with laryngospasm. METHODS: Secondary analysis of prospectively collected data from consecutively sedated patients, less than or equal to 22 years of age, at multiple locations at 64 member institutions of the Pediatric Sedation Research Consortium. The primary outcome was laryngospasm. The independent variables in the multivariable model included American Society of Anesthesiologists category, age, sex, concurrent upper respiratory infection, medication regimen, hospital sedation location, whether the procedure was painful, and whether the procedure involved the airway. The analysis included adjusted odds ratios (aORs) and predicted probabilities. RESULTS: We analyzed 276,832 sedations with 913 reported events of laryngospasm (overall unadjusted prevalence 3.3:1,000). A younger age, a higher American Society of Anesthesiologists category, a concurrent upper respiratory infection (aOR 3.94, 2.57 to 6.03; predicted probability 12.2/1,000, 6.3/1,000 to 18.0/1,000), and airway procedures (aOR 3.73, 2.33 to 5.98; predicted probability 9.6/1,000, 5.2/1,000 to 13.9/1,000) were associated with increased risk. Compared with propofol alone, propofol combination regimens had increased risk (propofol+ketamine: aOR 2.52, 1.41 to 4.50; predicted probability 7.6/1,000, 3.1/1,000 to 12/1,000; and propofol+dexmedetomidine: aOR 2.10, 1.25 to 3.52; predicted probability 6.3/1,000, 3.7,/1,000 to 8.9/1,000). Among patients with laryngospasm, the resulting outcomes included desaturation less than 70% for more than 30 seconds (19.7%), procedure not completed (10.6%), emergency airway intervention (10.0%), endotracheal intubation (5.3%), unplanned admission/increase in level of care (2.3%), aspiration (1.1%), and cardiac arrest (0.2%). CONCLUSION: We found increased associations of laryngospasm in pediatric procedural sedation with multiple biologic factors, procedure types, and medication regimens. However, effect estimates showed that the laryngospasm prevalence remained low, and this should be taken into consideration in sedation decisionmaking.

Safety of office-based flexible endoscopic procedures of the pharynx and larynx under topical anesthesia.

INTRODUCTION: Flexible endoscopic procedures (FEP) using a working channel allowed otolaryngologists to perform more procedures on the pharynx and the larynx under local anesthesia. The purpose of this work is to demonstrate the feasibility and safety of this technique by studying the adverse effects of this practice in an office-based setting. METHODS: This is a monocentric retrospective cohort study. We searched the database using the French procedural code for FEP performed in an outpatient setting between January 2005 and December 2020. Data regarding the patient's characteristics, indications, and periprocedural complications were extracted. RESULTS: In total, we included 231 patients with a total of 308 FEP: 36% biopsy, 20% hyaluronic acid injection (including 3.5% at the level of the cavum), 20% injection of other substances (in descending order: botulinum toxin, cidofovir, physiological serum, cortisone), 20% exploration for an occult tumor, 3% samples for microbiological analysis, 1% other procedures. Of the 308 FEP included in this study, 24 patients (10.3%) had complications corresponding to 7.8% of the procedures performed. During the procedures, reported complications include minor laryngeal bleeding (n = 5), vasovagal syncope (n = 5), laryngospasm (n = 1) or nausea (n = 3), dysphagia (n = 3), and voice disorders (n = 3). Post-procedural complications were hypertensive crisis (n = 1), asthma attack (n = 1), pneumonia (n = 1), laryngitis (n = 1). Using the Clavien-Dindo classification system, these complications could be defined as grade I (laryngeal bleeding, vasovagal syncope, laryngospasm, dysphagia, nausea, voice disorders, and laryngitis) and grade II (hypertensive crisis, asthma attack, pneumonia) in 9.1% and 1.2% of cases, respectively. Most of these complications were self-limiting, while asthma attacks, pneumonia, laryngitis, and voice disorders required a medical intervention. All complications were managed without sequelae. There was no serious complication grade (no grade III, IV or V). CONCLUSIONS: FEP, which is now well standardized in our institution, makes it possible to carry out a wide range of interventions with little morbidity. These results are in line with those of literature but this technique remains out of nomenclature in France. Our experience led to the development of an evidence-based standard of care that can serve as a framework for practitioners on a nationwide level, while the work to establish official guidelines by the French society of phoniatrics and laryngology is in progress.

Seizures induce obstructive apnea in DBA/2J audiogenic seizure-prone mice: Lifesaving impact of tracheal implants.

The mechanism(s) for sudden death in epilepsy (SUDEP) remain(s) unknown, but seizure spread to brainstem areas serving autonomic and respiratory function is critical. In a rat model, we established a mechanism for SUDEP that involves seizure-induced laryngospasm and obstructive apnea lasting until respiratory arrest. We hypothesized that DBA/2J mice, which display lethal audiogenic seizures, would be protected from death by implanting a tracheal T-tube as a surrogate airway. In a 2 × 2 design, mice were implanted with either open or closed tracheal T-tubes and treated with either low-dose ketamine/xylazine to moderate thoracic spasm during the tonic seizure phase or no drug. Animals receiving both treatments had the highest survival rate, followed by animals receiving the open tube without ketamine/xylazine. The odds ratio for survival was >20 higher with an open T-tube (odds ratio = 24.14). The impact of open tracheal tubes indicates that the mechanism of death in DBA/2J mice involves seizure-induced upper airway obstruction until respiratory arrest. These results, our rat work, and our demonstration of inspiratory effort-based electromyographic signals and electrocardiographic abnormalities in rats and humans suggest that seizure-induced laryngospasm and obstructive apnea directly link seizure activity to respiratory arrest in these sudden death examples.

Mechanisms and prevention of acid reflux induced laryngospasm in seizing rats.

OBJECTIVE: Recent animal work and limited clinical data have suggested that laryngospasm may be involved in the cardiorespiratory collapse seen in sudden unexpected death in epilepsy (SUDEP). In previous work, we demonstrated in an animal model of seizures that laryngospasm and sudden death were always preceded by acid reflux into the esophagus. Here, we expand on that work by testing several techniques to prevent the acid reflux or the subsequent laryngospasm. METHODS: In urethane anesthetized Long Evans rats, we used systemic kainic acid to acutely induce seizure activity. We recorded pH in the esophagus, respiration, electrocorticography activity, and measured the liquid volume in the stomach postmortem. We performed the following three interventions to attempt to prevent acid reflux or laryngospasm and gain insights into mechanisms: fasting animals for 12 h, severing the gastric nerve, and electrical stimulation of either the gastric nerve or the recurrent laryngeal nerve. RESULTS: Seizing animals had significantly more liquid in their stomach. Severing the gastric nerve and fasting animals significantly reduced stomach liquid volume, subsequent acid reflux, and sudden death. Laryngeal nerve stimulation can reverse laryngospasm on demand. Seizing animals are more susceptible to death from stomach acid-induced laryngospasm than nonseizing animals are to artificial acid-induced laryngospasm. SIGNIFICANCE: These results provide insight into the mechanism of acid production and sudden obstructive apnea in this model. These techniques may have clinical relevance if this model is shown to be similar to human SUDEP.

Acute Postobstructive Pulmonary Edema Following Laryngospasm in Elderly Patients: A Case Report.

Only a few cases regarding postobstructive pulmonary edema following laryngospasm in older patients aged more than 60 years have been reported; however, acute pulmonary edema or pulmonary hemorrhage would be more deadly to elderly patients who have cerebrovascular disease than young healthy adults. After review of the literature, we report an unusual case of a 67-year-old man with ischemic cerebrovascular disease, who underwent carotid angioplasty and stenting and experienced severe pulmonary edema and hemorrhage secondary to laryngospasm after general anesthesia with laryngeal mask airway. The patient required positive-pressure ventilation, supportive treatment, and active cerebroprotection in the intensive care setting for 3 days before the edema resolved, and subsequently made a complete recovery without new onset of neurologic sequelae. The possible pathophysiological mechanisms, precaution, and preventative strategy of postobstructive pulmonary edema in older patients are discussed.

Paroxysmal laryngospasm: Episodic closure of the upper airway.

Paroxysmal laryngospasm is an episodic event, resulting in complete closure of the larynx caused by hypersensitization of laryngeal tissue and protective laryngeal reflexes. This condition most often occurs secondary to laryngopharyngeal reflux. Prognosis generally is good after treatment is initiated; however, often because of a misunderstanding of the clinical course and potential causes, patients with paroxysmal laryngospasm can go untreated. This article describes paroxysmal laryngospasm, similarly presenting diseases, and treatment strategies.

Efficacy of a new dual channel laryngeal mask airway, the LMA®Gastro™ Airway, for upper gastrointestinal endoscopy: a prospective observational study.

BACKGROUND: Significant cardiorespiratory events are frequent in patients undergoing gastrointestinal endoscopy. Central to the occurrence of respiratory events is an unsecured airway. This study sought to determine the efficacy of a new laryngeal mask airway, the LMA®GastroTM Airway (Teleflex Medical, Athlone, Ireland), in patients undergoing upper gastrointestinal endoscopy. New design features include a dedicated channel for oesophageal intubation and separate channel with terminal cuff for lung ventilation. METHODS: In a prospective, open label, observational study, 292 ASA physical status classification 1 and 2 patients at low risk of pulmonary aspiration undergoing upper gastrointestinal endoscopy received i.v. propofol anaesthesia and standardized insertion of the LMA®GastroTM Airway. Endoscopy outcomes included insertion success, first attempt success, and ease of endoscope insertion. LMA®GastroTM Airway outcomes included insertion success, first attempt success, ease of insertion, lowest oxygen saturation, airway compromise, laryngospasm, bloodstained device, and sore throat. RESULTS: Per protocol analysis (n=290), the endoscopy success rate amongst the cohort with successful LMA®GastroTM Airway insertion was 99% [95% confidence interval (CI): 98, 100]. LMA®GastroTM Airway insertion success rate (n=292) was 99% (95% CI: 98, 100). For endoscopy and LMA®GastroTM Airway insertion success, the lower limit of the 95% CIs was at least 98%, indicating LMA®GastroTM Airway efficacy. Median (inter-quartile range) lowest intraoperative oxygen saturation was 98% (98, 99). Only one serious adverse event occurred (re-admission for sore throat and inability to tolerate fluids) and was reported to the Tasmanian Health and Medical Human Research Ethics Committee. CONCLUSIONS: The LMA®GastroTM Airway appears effective for clinical use in upper gastrointestinal endoscopy. CLINICAL TRIAL REGISTRATION: ACTRN12616001464459.

Laryngeal mask airway Unique™ position in paediatric patients undergoing magnetic resonance imaging (MRI): prospective observational study.

BACKGROUND: Laryngeal mask UNIQUE® (LMAU) is supraglottic airway device with good clinical performance and low failure rate. Little is known about the ideal position of the LMAU on the magnetic resonance imaging (MRI) and whether radiological malposition can be associated with clinical performance (audible leak) in children. The primary aim of the study was to evaluate incidence of the radiologic malposition of the LMAU according to size. The secondary outcome was the clinical performance and associated complications (1st attempt success rate, audible leak) in LMAUs in correct position vs. radiologically misplaced LMAUs. METHODS: In prospective observational study, all paediatric patients undergoing MRI of the brain under general anaesthesia with the LMAU were included (1.9.2016-16.5.2017). The radiologically correct position: LMAU in hypopharynx, proximal cuff opposite to the C1 or C2 and distance A (proximal cuff end and aditus laryngis) ≤ distance B (distal cuff end and aditus laryngis). Malposition A: LMAU outside the hypopharynx. Malposition B: proximal cuff outside C1-C2. Malposition C: distance A ≥ distance B. We measured distances on the MRI image. Malposition incidence between LMAU sizes and first attempt success rate in trainees and consultant groups was compared using Fisher exact test, difference in incidence of malpositions using McNemar test and difference in leakage according to radiological position using two-sample binomial test. RESULTS: Overall 202 paediatric patients were included. The incidence of radiologically defined malposition was 26.2% (n = 53). Laryngeal mask was successfully inserted on the 1st attempt in 91.1% (n = 184) cases. Audible leak was detected in 3.5% (n = 7) patients. The radiologically defined malposition was present in 42.9% (n = 3) cases with audible leak. The rate of associated complications was 1.5% (n = 3): laryngospasm, desaturation, cough. In 4.0% (n = 8) the LMAU was soiled from blood. Higher incidence of radiological malposition was in LMAU 1.0, 1.5 and LMAU 3, 4 compared to LMAU 2 or LMAU 2.5 (p < 0.001). CONCLUSION: Malposition was not associated with impaired clinical performance (audible leak, complications) of the LMAU or the need for alternative airway management. TRIAL REGISTRATION: Clinicaltrials.gov  (NCT02940652) Registered 18 October 18 2016.

[Laryngospasm in amyotrophic lateral sclerosis : A case report]. / Laryngospasmus bei Amyotropher Lateralsklerose : Ein Fallbericht.

Laryngospasm in amyotrophic lateral sclerosis is a symptom seldom described in neurological literature. Despite the self limiting character it means a life threatening condition for the patient himself. This case report and the following discussion tries to look upon underlying causes and options of therapy.

Validation of Adapted Dartmouth Operative Conditions Scale for sedation during pediatric esophagogastroduodenoscopy.

AIMS: Pediatric esophagogastroduodenoscopy requires deep sedation as it involves stimulation of the airway. Frequency of adverse events is higher with esophagogastroduodenoscopy. Hence, monitoring needs sedation scales like the Dartmouth Operative Condition Scale that identifies safe states of sedation. This study aims at validating the Adapted Dartmouth Operative Condition Scale for sedation rating by pediatricians during pediatric esophagogastroduodenoscopy. METHODS: Items in the Dartmouth Operating Conditions Scale were adapted for pediatric esophagogastroduodenoscopy. Videos of 35 procedures were recorded. The recording started 10 min before sedation and continued till recovery. The videos were split into preprocedure videos, intraprocedure videos, and recovery videos, and further split into 30-s clips. Twenty representative intraprocedure videos clips were selected. Ten raters scored the videos with the Adapted Dartmouth Operating Conditions Scale and modified-COMFORT score. The Adapted Dartmouth Operating Conditions Scale scoring was repeated after a month. The preprocedure videos, intraprocedure videos, and recovery videos of ten patients (six clips each) were scored by one rater to assess responsiveness. RESULTS: The Adapted Dartmouth Operating Conditions Scale detected nonoptimal sedation states including laryngospasm due to undersedated states. It showed fair interrater reliability at timeline-1 (intraclass correlation coefficient = 0.45) and timeline-2 (intraclass correlation coefficient = 0.65) but poor intrarater reliability (intraclass correlation coefficient = 0.32). There was significant positive correlation with modified-COMFORT (Spearman's rank order correlation, r = 0.150). Responsiveness was demonstrated by the difference in the preprocedure videos, intraprocedure videos, and recovery videos scores (F = 126.50). CONCLUSION: The Adapted Dartmouth Operating Conditions Scale detects nonoptimal sedation states during pediatric-esophagogastroduodenoscopy. It shows good criterion validity, interrater reliability, and responsiveness. Poor intrarater reliability seen in our study could be due to item ambiguity arising from the mode of training of the raters in the Dartmouth Operating Conditions Scale.

Office-Based Anesthesia: Safety and Outcomes in Pediatric Dental Patients.

The number of children with caries requiring general anesthesia to achieve comprehensive dental care and the demand for dentist anesthesiologists to provide ambulatory anesthesia for these patients is increasing. No current published studies examine the safety and outcomes of ambulatory anesthesia performed by dentist anesthesiologists for dental procedures in pediatric patients, and there is no national requirement for reporting outcomes of these procedures. In 2010, the Society for Ambulatory Anesthesia Clinical Outcomes Registry was developed. This Web-based database allows providers of ambulatory anesthesia to track patient demographics and various outcomes of procedures. Our study is a secondary analysis of data collected in the registry over a 4-year period, 2010-2014. Of the 7041 cases reviewed, no cases resulted in serious complications, including death, anaphylaxis, aspiration, cardiovascular adverse events, or neurologic adverse events. Of the 7041 cases reviewed, 196 (3.0%) resulted in a predischarge or postdischarge adverse event. The predischarge adverse event occurring with the highest frequency was laryngospasm, occurring in 35 cases (0.50%). The postdischarge adverse event occurring with the highest frequency was nausea, reported by 99 patients (5.0%). This study provides strong clinical outcomes data to support the safety of office-based anesthesia as performed by dentist anesthesiologists in the treatment of pediatric dental patients.

Asphyxia due to laryngeal spasm as a severe complication of awake deep brain stimulation for Parkinson's disease: a case report.

BACKGROUND: In accordance with German neurosurgical and neurological consensus recommendations, lead placements for deep brain stimulation (DBS) in patients with Parkinson's disease (PD) are usually performed with the patient awake and in "medication off" state. This allows for optimal lead position adjustment according to the clinical response to intraoperative test stimulation. However, exacerbation of Parkinsonian symptoms after withdrawal of dopaminergic medication may endanger the patient by inducing severe "off" state motor phenomena. In particular, this can be a problem in awake craniotomies utilizing intraoperative airway management and resuscitation. CASE PRESENTATION: We report the case of a PD patient with progressive orofacial and neck muscle dystonia resulting in laryngeal spasm during DBS lead placement. This led to upper airway compromise and asphyxia, requiring resuscitation. CONCLUSIONS: Laryngeal spasms may occur as a rare "off" state motor complication in patients with PD. Other potential causes of intraoperative difficulties breathing include bilateral vocal cord palsy, positional asphyxia, and silent aspiration. In our practice, we have adjusted our medication regimen and now allow patients to receive their standard dopaminergic medication until the morning of surgery. Neurologists and neurosurgeons performing lead placement procedures for PD should be aware of this rare but unsafe condition to most optimized treatment.

Complications of Moderate Sedation Versus Deep Sedation/General Anesthesia for Adolescent Patients Undergoing Third Molar Extraction.

PURPOSE: To examine the complications resulting from moderate sedation versus deep sedation/general anesthesia for adolescent patients undergoing third molar extraction and determine whether any differences in complication risks exist between the 2 levels of sedation. MATERIALS AND METHODS: We performed a prospective study of the Oral and Maxillofacial Surgery Outcomes System from January 2001 to December 2010. The primary predictor variable was the level of sedation, divided into 2 groups: moderate sedation versus deep sedation/general anesthesia. The primary outcome was the incidence of adverse complications resulting from the sedation level. Differences in the cohort characteristics were analyzed using the independent samples t test, χ(2) test, and analysis of variance, as appropriate. Multivariable logistic regression was used to measure the effect the level of sedation had on the adverse complication rate. RESULTS: Patients in the moderate sedation group had a complication rate of 0.5%, and patients in the deep sedation/general anesthesia group had a complication rate of 0.9%. Compared with moderate sedation, deep sedation/general anesthesia did not pose a significantly increased risk of adverse anesthesia complications (adjusted odds ratio 1.63, 95% confidence interval 0.95 to 2.81; P = .077). CONCLUSIONS: The results of our study have shown that the risk of adverse anesthesia complications is not increased when choosing between moderate and deep sedation/general anesthesia for adolescent patients undergoing third molar extraction.

Anesthetic care and perioperative complications in children with Sanfilipo Syndrome Type A.

BACKGROUND: Patients with mucopolysaccharidoses (MPS) are generally considered high risk for anesthesia care, owing to disease-related factors. Sanfilippo syndrome type A (MPS IIIA) is the most frequently occurring MPS. Anesthesia-specific information for MPS IIIA is not readily available in the literature. OBJECTIVES: To report post hoc analyses on anesthesia care and outcomes from a 2-year study of the natural history of patients with untreated MPS IIIA (NCT01047306). METHODS: Subjects were ≥1 year of age, developmental age ≥1 year, and without significant central nervous system impairment (other than that due to MPS IIIA) or issues that would preclude study procedures. Procedures requiring general anesthesia included brain/abdominal magnetic resonance imaging, lumbar puncture, and echocardiography. Sedation, intubation, and extubation procedures as well as postoperative airway problems were recorded at baseline and 6, 12, and 24 months of age. RESULTS: Twenty-five patients (baseline age, 13-220 months) received a total of 94 general anesthetics. Patients successfully received oral sedation prior to 76 of 94 anesthetics. No patients required airway intervention or oxygen supplementation during sedation. All anesthesia providers described facemask ventilation and endotracheal intubations as 'easy'. All subjects were successfully extubated after completion of the procedures. No patients required reintubation. Six (24%) patients had episodes of postoperative airway problems: wheezing (7/94, 7.4%), croup (6/94, 6.4%), and laryngospasm (2/94, 2.1%). CONCLUSION: We found no change in the modified Cormack-Lehane intubation grades in 25 Sanfilippo syndrome type A children over the 2-year study period.

Prevalence of exercise-induced bronchoconstriction and exercise-induced laryngeal obstruction in a general adolescent population.

BACKGROUND: Exercise-induced respiratory symptoms are common among adolescents. Exercise is a known stimulus for transient narrowing of the airways, such as exercise-induced bronchoconstriction (EIB) and exercise-induced laryngeal obstruction (EILO). Our aim was to investigate the prevalence of EIB and EILO in a general population of adolescents. METHODS: In this cross-sectional study, a questionnaire on exercise-induced dyspnoea was sent to all adolescents born in 1997 and 1998 in Uppsala, Sweden (n=3838). A random subsample of 146 adolescents (99 with self-reported exercise-induced dyspnoea and 47 without this condition) underwent standardised treadmill exercise tests for EIB and EILO. The exercise test for EIB was performed while breathing dry air; a positive test was defined as a decrease of ≥10% in FEV1 from baseline. EILO was investigated using continuous laryngoscopy during exercise. RESULTS: The estimated prevalence of EIB and EILO in the total population was 19.2% and 5.7%, respectively. No gender differences were found. In adolescents with exercise-induced dyspnoea, 39.8% had EIB, 6% had EILO and 4.8% had both conditions. In this group, significantly more boys than girls had neither EIB nor EILO (64.7% vs 38.8%; p=0.026). There were no significant differences in body mass index, lung function, diagnosed asthma or medication between the participants with exercise-induced dyspnoea who had or did not have a positive EIB or EILO test result. CONCLUSIONS: Both EIB and EILO are common causes of exercise-induced dyspnoea in adolescents. EILO is equally common among girls and boys and can coexist with EIB.

Laryngospasm With Apparent Aspiration During Sedation With Nitrous Oxide.

Nitrous oxide and oxygen mixture has become increasingly popular for the procedural sedation and analgesia of children in the emergency department. In general, nitrous oxide is regarded as a very safe agent according to large case series. We report a case of single-agent nitrous oxide sedation of a child, complicated by laryngospasm and radiographically confirmed bilateral upper lobe pulmonary opacities. Although rarely reported with parenteral sedative agents, laryngospasm and apparent aspiration has not been previously reported in isolated nitrous oxide sedation. This case highlights that, similar to other sedative agents, nitrous oxide administration also needs to be conducted by staff and in settings in which airway emergencies can be appropriately managed.

Early versus late removal of the laryngeal mask airway (LMA) for general anaesthesia.

BACKGROUND: The laryngeal mask airway (LMA) is a safe and effective modality to maintain the airway for general anaesthesia during surgical procedures. The LMA is removed at the end of surgery and anaesthesia, when the patient maintains an adequate respiratory rate and depth. This removal of the LMA can be done either when the patient is deep under anaesthesia (early removal) or only after the patient has regained consciousness (late removal). It is not clear which of these techniques is superior. OBJECTIVES: The objective of this review was to compare the safety of LMA removal in the deep plane of anaesthesia (early removal) versus removal in the awake state (late removal) for participants undergoing general anaesthesia. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2014, Issue 8); MEDLINE (1966 to August 2014); EMBASE (1980 to August 2014); LILACS (1982 to August 2014); CINAHL (WebSPIRS; 1984 to August 2014); and ISI Web of Science (1984 to August 2014). We searched for ongoing trials through various trial registration websites. In addition, we searched conference proceedings and reference lists of relevant articles. SELECTION CRITERIA: We included randomized controlled trials (RCTs) on adults and children undergoing elective general anaesthesia using the LMA, that compared early removal of the LMA (defined as removal of the LMA in the deep plane of anaesthesia) versus late removal of the LMA (defined as removal of the LMA after the patient is awake). DATA COLLECTION AND ANALYSIS: Two authors independently assessed trial quality and extracted data. We contacted study authors for additional information. We used a random-effects model to generate forest plots from the data. MAIN RESULTS: We identified a total of 9188 citations and included 15 RCTs conducted on 2242 participants in this review. All trials used the LMA Classic in American Society of Anesthesiologists (ASA) physical status I or II for patients undergoing elective general anaesthesia. Children were enrolled in 11 trials and adults in five trials. None of the trials were of high methodological quality. Eight of the 15 studies had adequate generation of random sequence, whereas only one trial had adequate concealment of random sequence. Three trials had blinded the outcome assessor. Thus, the majority of the studies appeared to have a high risk of bias in the study design.Using the GRADE approach, we found low quality evidence that the risk of laryngospasm was similar with early removal of the LMA (3.3%) versus late removal (2.7%): risk ratio (RR) 1.23, 95% confidence interval (CI) 0.74 to 2.03; 11 trials, 1615 participants. The quality of evidence was very low that the risk of coughing was less after early removal (13.9%) than late removal (19.4%): RR 0.52, 95% CI 0.29 to 0.94; 11 trials, 1430 participants. The quality of evidence for the risk of desaturation was also very low; there was no difference between early removal (7.9%) and late removal (10.1%): RR 0.68, 95% CI 0.4 to 1.16; 13 trials, 2037 participants. We found low quality evidence that the risk of airway obstruction was higher with early removal (15.6%) compared to late removal of the LMA (4.6%): RR 2.69, 95% CI 1.32 to 5.5; eight trials, 1313 participants. AUTHORS' CONCLUSIONS: This systematic review suggests that current best evidence comparing early versus late removal of the LMA in participants undergoing general anaesthesia does not demonstrate superiority of either intervention. However, the quality of evidence available is either low or very low. There is a paucity of well designed RCTs and a need for large scale RCTs to demonstrate whether early removal or late removal of the LMA is better after general anaesthesia.

Airway reactions and emergence times in general laryngeal mask airway anaesthesia: a meta-analysis.

BACKGROUND: Desflurane's short emergence time supports fast track anaesthesia. Data on the rate of upper airway complications and emergence time when desflurane is used with laryngeal mask airway (LMA) are controversial and limited. OBJECTIVES: To compare recovery time variables and the rates of upper airway adverse events in patients with an LMA undergoing general surgery with desflurane, sevoflurane, isoflurane or propofol anaesthesia. DESIGN: A systematic review and meta-analysis of randomised controlled trials (RCTs). DATA SOURCES: A systematic search for eligible RCTs in Embase (Elsevier) and in PubMed (National Library of Medicine) databases up to September 2013. ELIGIBILITY CRITERIA: RCTs investigating the rates of cough overall, cough at emergence, laryngospasm, time to eye opening, time to removal of the LMA, time to respond to command and time to state date of birth in patients with an LMA, during emergence from desflurane, sevoflurane, isoflurane or propofol anaesthesia. RESULTS: Thirteen RCTs were included and analysed. We found a strong interstudy variability. There was no difference in the rates of upper airway events between desflurane and sevoflurane or between desflurane and a control group consisting of all the other anaesthetics combined. Comparing desflurane (n = 284) with all other anaesthetic groups (n = 313), the risk ratio [95% confidence interval (95% CI)] was 1.12 (0.63 to 2.02, P = 0.70). Cough at emergence was only measured in patients receiving desflurane (n = 148) and sevoflurane (n = 146): the risk ratio (95% CI) was 1.49 (0.55 to 4.02, P = 0.43). Laryngospasm was rare and there was no significant difference in its incidence when desflurane (n = 262) was compared with all other anaesthetics combined (n = 289; risk ratio 1.03; 95% CI 0.33 to 3.20, P = 0.96). The times of all emergence variables were significantly faster in the desflurane group than in all other groups. CONCLUSION: When using an LMA, upper airway adverse reactions in association with desflurane anaesthesia were no different from those noted with sevoflurane, isoflurane or propofol anaesthesia. Emergence from general anaesthesia with desflurane is significantly faster than all the other anaesthetics. Due to interstudy variations and the small size of the trials, further large-scale, multicentre studies are required to confirm or refute the results of this meta-analysis.

Acute dyspnea caused by hypocalcemia-related laryngospasm.

BACKGROUND: Laryngospasm is a rare cause of stridor in adults, and laryngospasm due to hypocalcemia is an unusual finding. CASE REPORT: We present a case of an adult woman with acute dyspnea. A week prior to presentation, she experienced short episodes of a pinching feeling in her throat and difficulty breathing. On primary assessment, stridor and a positive Trousseau sign were noted. Laboratory examination showed hypocalcemia. We concluded that the dyspnea was caused by laryngospasm due to hypocalcemia. Hypocalcemia was treated promptly, and stridor and dyspnea resolved rapidly. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Laryngospasm is a rare, but serious and potentially lethal, complication of hypocalcemia in adults. In every adult presenting with acute dyspnea and stridor, the possibility of hypocalcemia should be considered. Hypocalcemia should be treated promptly.

Perioperative complications of cochlear implant surgery in children.

Cochlear implant is a commonly performed surgery for hearing loss in pre-school and school children. However, data on anesthesia management and anesthesia-related complications are sparse. We retrospectively reviewed the data of our institute from January, 2007 to December, 2012. Medical records and anesthesia charts of all the patients who had undergone cochlear implant under general anesthesia between this period were reviewed. Information related to the demographic profile, preoperative evaluation, anesthetic techniques, and perioperative complications were collected and analyzed. A total of 190 patients underwent cochlear implant surgery for pre-lingual (175) and post-lingual (15) deafness. General endotracheal anesthesia with inhalational agents was used in all the cases. Difficult intubation was encountered in three patients. Anesthesia-related complications were laryngospasm at extubation (4.73 %), emergence agitation (2.63 %), and postoperative nausea and vomiting (1.05 %). Major surgical complications were CSF leak without meningitis (3.15 %), device migration/failure (1.05 %), and flap infection (1.57 %). Cochlear implant under general anesthesia in small children is safe and anesthesia-related complications were minimal. Surgical complications, although more frequent, were predominantly minor and self-limiting.