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.

Negative-pressure pulmonary edema after laparoscopic appendectomy.

Negative-pressure pulmonary edema (NPPE) is acute-onset bilateral pulmonary interstitial edema. This condition can be caused by significant negative intrathoracic pressure generated by large inspiratory effort against acute upper airway obstruction. Postoperative NPPE is rare but potentially life-threatening if not recognized and treated promptly. This article describes a patient who developed postoperative NPPE following a laparoscopic appendectomy.

Laryngeal hypersensitivity in the World Trade Center-exposed population: the role for respiratory retraining.

Upper airway symptoms among responders to the terrorist attack on 9/11 are progressive and multifactorial. For those symptoms that are laryngeal in origin, we are using a multidisciplinary approach that includes respiratory retraining and laryngeal desensitization through a speech pathologist trained in airway disorders. Our treatment paradigm and laryngeal hypersensitivity are discussed in this essay.

"GIOSAT": a tool to assess CanMEDS competencies during simulated crises.

PURPOSE: Our objective was to develop and evaluate a Generic Integrated Objective Structured Assessment Tool (GIOSAT) to integrate Medical Expert and intrinsic (non-medical expert) CanMEDS competencies with non-technical skills for crisis simulation. METHODS: An assessment tool was designed and piloted using two pediatric anesthesia scenarios (laryngospasm and hyperkalemia). Following revision of the tool, we used previously recorded videos of anesthesia residents (n = 50) who managed one of two intraoperative advanced cardiac life support (ACLS) scenarios (ventricular tachycardia or ventricular fibrillation). Four independent trained raters, blinded to the residents' level of training, analyzed the video recordings using the GIOSAT scale. Inter-rater reliability was calculated using intraclass correlations (ICCs) for single raters (single measure) and the average of the four raters (average measure), and construct validity was investigated by correlating GIOSAT scores with postgraduate year of residency (PGY). RESULTS: Total GIOSAT scores for the ACLS scenarios had single measure ICCs of 0.62 and average measure ICCs of 0.85. Inter-rater reliability was substantial for both Medical Expert and intrinsic competencies (single measure ICCs 0.69 and 0.62, respectively; average measure ICCs 0.90 and 0.82, respectively). We found significant correlations between PGY level and total GIOSAT score (r = 0.36; P = 0.011) and between PGY level and Medical Expert competencies (r = 0.42; P = 0.003); however, correlations were not found between PGY level and intrinsic CanMEDS competencies (r = 0.24; P = 0.09). CONCLUSION: Inter-rater reliability of the total GIOSAT scores using four trained raters was substantial. Significant correlation between PGY and (i) total GIOSAT score and (ii) Medical Expert competencies supports construct validity. Evidence of validity was not obtained for intrinsic CanMEDS competencies.

Vagal nerve stimulator-associated sleep disordered breathing secondary to vagal-induced laryngospasm in pediatric populations: Case presentation and systematic review.

OBJECTIVES: Sleep disordered breathing (SDB) is a well-documented complication of vagus nerve stimulation (VNS) in the literature. Yet, a formal consensus on its management has not been established, particularly in the pediatric population. This study aims to evaluate the current literature on VNS-associated SDB in order to further characterize its presentation, pathogenesis, diagnosis, and treatment. METHODS: A literature review from 2001 to November 8, 2021 was conducted to search for studies on SDB during vagal nerve stimulation in pediatric populations. RESULTS: Of 277 studies screened, seven studies reported on pediatric patients with VNS-associated SDB. Several investigators found on polysomnogram that periods of apnea/hypopnea correlated with VNS activity. When VNS settings were lowered or turned off, symptoms would either improve or completely resolve. CONCLUSION: VNS-associated SDB is a well described complication of VNS implantation, occurring due to an obstructive process from vagal stimulation and laryngeal contraction. Diagnosis can be made via polysomnogram. Recommended treatment is through adjustment of VNS settings. However, those who are unable to tolerate this, or who have had pre-existing obstructive issues prior to VNS, should pursue other treatment options such as non-invasive positive pressure or surgery directed by DISE findings.

Postoperative adverse respiratory events in preschool patients with inhaled foreign bodies: an analysis of 505 cases.

OBJECTIVES: To identify the risk factors associated with postoperative adverse respiratory events in preschool-aged children with inhaled foreign bodies (FBs) undergoing rigid bronchoscopy. BACKGROUND: Foreign bodies aspiration is the most common cause of admission in pediatric emergency in otolaryngology service. Performance of rigid bronchoscopy is the standard treatment for removal of FBs in children. In some cases, severe respiratory events (complete laryngospasm and pneumothorax) may cause anesthesia-related morbidity and mortality. However, the association between patient-related factors and postoperative complications in preschool-aged children with inhaled FBs undergoing rigid bronchoscopy is unclear. METHODS: We carried out a large prospective, single-institution review of anesthesia for 505 American Society of Anesthesiologists I-III preschool children aged ≤7 with inhaled FBs undergoing rigid bronchoscopy. Patients with postoperative adverse respiratory events were classified into two groups: the minor events group [hemorrhage, minor desaturation, and partial laryngospasm (wheezing, stridor, and dyspnea)) and the major events group (complete laryngospasm, including major desaturation, and pneumothorax). RESULTS: The incidence of postoperative adverse respiratory events was 9.5% in preschool-aged children with inhaled FBs undergoing rigid bronchoscopy. Preoperative respiratory impairment was associated with an increased risk for the complicate (P < 0.01). Pneumothorax occurred in 4 (0.8%) patients. There was 1 (0.2%) death from severe respiratory-related complications. CONCLUSIONS: Preoperative respiratory impairment may develop the patients with FBs into postoperative adverse respiratory events.

[The use of "laryngospasm notch" in a patient who was unable to breathe during general anesthesia with a ProSeal laryngeal mask airway--the effect of Kino's approach].

We report a case where "laryngospasm notch" technique was used in a patient to initiate spontaneous respiration during general anesthesia. The patient was a 43-year-old woman who underwent conization. A Pro-Seal laryngeal mask airway was inserted after induction of general anesthesia. General anesthesia was maintained with sevoflurane (1.7-2%) and fentanyl. Surgical course was uneventful until the patient became unable to breathe towards the end of surgery. Positive-pressure ventilation was applied, but the patient could not be ventilated. "Laryngospasm notch" technique was performed by applying digital pressure in front of the tragus of the ears, and the patient began to breathe spontaneously. We describe our experience with the "laryngospasm notch" technique applied to the front of the tragus of the ears to treat laryngospasm.

Management of Refractory Laryngospasm.

Laryngospasm has been well described in patients emerging from general anesthesia (GA) and is routinely managed with intermittent positive-pressure mask ventilation, a temporary increase in the depth of anesthesia, or small, titrated amounts of succinylcholine. Patients with severe laryngospasm require reintubation to maintain adequate oxygenation and ventilation. However, reintubation may be only a temporary solution because laryngospasm may recur during re-emergence and re-extubation; thus, anesthesiologists need a comprehensive plan that addresses potential causes of laryngospasm and incorporates continuous positive airway pressure (CPAP) for patients with difficulty emerging from GA. Transnasal humidified rapid-insufflation ventilatory exchange (THRIVE) is a noninvasive ventilation and oxygenation technique used to provide apneic oxygenation, which also generates CPAP. THRIVE uses a high-flow nasal cannula and is more easily tolerated than CPAP with a tight-fitting mask. To our knowledge, we present the first case of refractory laryngospasm during emergence from GA that was successfully managed with THRIVE.

Negative Pressure Pulmonary Edema: A Case Report.

Negative pressure pulmonary edema is an uncommon complication of the extubation of the endotracheal tube. An increase in intrathoracic pressure and negative pressure of the lung caused by acute laryngeal spasm results from acute upper respiratory obstruction causing life-threatening pulmonary edema by alveolar-capillary damage is called negative pressure pulmonary edema. We here describe 28-years old female case the preoperative diagnosis of pelvic inflammatory disease undergoing exploratory laporoscopy caused negative pressure pulmonary edema while extubation. With the immediate treatment, the patient was discharged without any abnormalities.

Paroxysmal Laryngospasm: A Rare Condition That Respiratory Physicians Must Distinguish from Other Diseases with a Chief Complaint of Dyspnea.

Background: In recent years, we have observed respiratory difficulty manifested as paroxysmal laryngospasm in a few outpatients, most of whom were first encountered in a respiratory clinic. We therefore explored how to identify and address paroxysmal laryngospasm from the perspective of respiratory physicians. Methods: The symptoms, characteristics, auxiliary examination results, treatment, and prognosis of 12 patients with paroxysmal laryngospasm treated in our hospital from June 2017 to October 2019 were analyzed. Results: Five males (42%) and 7 females (58%) were among the 12 Han patients sampled. The average age of the patients was 49.25 ± 13.02 years. The disease course ranged from 14 days to 8 years and was characterized by sudden dyspnea, an inability to inhale and exhale, a sense of asphyxia, and voice loss during an attack. Eight patients with gastroesophageal reflux were cured after antacid treatment. One case of upper respiratory tract infection (URI) was completely relieved after symptomatic treatment. One patient with left vocal cord paralysis experienced complete relief after specialist treatment by an otorhinolaryngologist. Episodes in 1 patient were significantly reduced after lifestyle improvement. One patient experienced spontaneous relief after rejecting treatment. Conclusions: Paroxysmal laryngospasm is a rare laryngeal disease that generally occurs secondary to gastroesophageal reflux disease (GERD), and antireflux therapy is frequently effective for its treatment. A respiratory physician should master and identify the symptoms and differentiate this condition from hysterical stridor, reflux-related laryngospasm, and asthma. Timely referral to otolaryngologists, gastroenterologists, and other specialists for standardized examination and regular treatment should be provided when necessary.

Intranasal flumazenil and naloxone to reverse over-sedation in a child undergoing dental restorations.

We describe a 3-year-old child who became over-sedated after receiving intranasal (IN) midazolam (0.53 mg.kg(-1)) and IN sufentanil (1 mcg.kg(-1)) for dental restorations in the dental office. Desaturation was attributed to laryngospasm, which was managed with positive pressure ventilation and oxygen. The sedation was reversed with a combination of IN flumazenil and naloxone.

Pediatric laryngospasm: prevention and treatment.

PURPOSE OF REVIEW: The purpose of this review is to discuss the risk factors associated with laryngospasm and the techniques used for prevention and treatment. We also summarize the prevention and treatment modalities in organized algorithms. RECENT FINDINGS: According to recent endoscopic studies, laryngospasm is always complete, thus airway management and intravenous therapy are indicated. Parental history of children having upper respiratory infection is associated with increased risk of laryngospasm. Anesthesia administered by a pediatric anesthesiologist is associated with lower incidence of laryngospasm. Intravenous anesthesia is associated with lower incidence of laryngospasm than inhalational anesthesia. In tracheal intubation, the use of muscle relaxants decreases laryngospasm. Deep laryngeal mask airway removal is associated with lower incidence of laryngospasm in sevoflurane or isoflurane anesthesia. In no intravenous line situation, laryngospasm can be treated with succinylcholine administration by intramuscular, intraosseous and intralingual routes. SUMMARY: Identifying the risk factors and taking the necessary precautions are the key points in prevention of laryngospasm. An experienced anesthesiologist is associated with lower incidence of laryngospasm. Airway management is the most essential part of treatment of laryngospasm. Drugs can be used as an adjunct in treatment of laryngospasm, especially when anesthesia is administered by beginners.

[The use of "laryngospasm notch" in two patients whose oxygen saturations dropped after tracheal extubation].

In 1998, Dr. Larson described the technique of applying pressure to the "laryngospasm notch" as the best treatment for laryngospasm. Yet, there are no case reports of using this technique in the literature. We report 2 cases of using this technique in patients whose oxygen saturation levels dropped after tracheal extubation. The first patient was a 48-year-old man who underwent laparoscopic cholecystectomy and the second patient was a 67-year-old man who underwent lumbar laminectomy. In both cases, induction of general anesthesia and surgery were uneventful. After surgery, we confirmed spontaneous respiration and the patients were able to respond and shake hands. However, immediately after extubation, the patients could not breathe and their oxygen saturation levels decreased to 76% and 84%, respectively. In the first patient, mask ventilation was easy and we used the "laryngospasm notch" technique during ventilation. However, in the second patient, mask ventilation was difficult and we used this technique prepared for re-intubation. In both cases, the patients began to breathe spontaneously shortly after using this technique and oxygen saturation increased to 100%. The incidence of laryngospasm is higher after tracheal extubation. The "laryngospasm notch" method is a good technique to treat this condition.

Laryngospasm: review of different prevention and treatment modalities.

Laryngospasm is a common complication in pediatric anesthesia. In the majority of cases, laryngospasm is self-limiting. However, sometimes laryngospasm persists and if not appropriately treated, it may result in serious complications that may be life-threatening. The present review discusses laryngospasm with the emphasis on the different prevention and treatment modalities.

Pediatric laryngospasm.

Pediatric laryngospasm is an anesthetic emergency. It is a relatively common phenomenon that occurs with varying frequency dependent on multiple factors. In view of this and the clear risks to the patient when it occurs, a consensus committee has been established to determine the evidence based management of this condition. This article will cover the definition, causes and recognition of laryngospasm and the evidence behind a proposed algorithm for its' management.

Intervention steps for treating laryngospasm in pediatric patients.

BACKGROUND: Laryngospasm, a potentially life-threatening complication of anesthesia, is reported more commonly in children (17.4/1000) than in the general population (8.7/1000). However, there are no clinical data on the optimal type and sequence of therapeutic interventions. We therefore characterized the interventions used at St. Jude Children's Research Hospital. METHODS: The institutional quality improvement database was reviewed to identify cases of laryngospasm that occurred from July 1999 through December 2002. Patient records were examined to determine the timing of laryngospasm, the airway management technique in use and the type of intervention used to treat the episode. RESULTS: Twenty one cases of laryngospasm occurred (1/1000) during 21 452 anesthetics delivered in the operating room (19%) or for diagnostic and therapeutic procedures outside of the operating room (81%). Episodes occurred during emergence (47.6%), induction (28.6%) and maintenance (23.8%). Thirty-eight percent of patients responded to airway repositioning and continuous positive airway pressure. Ten patients (47.6%) were given muscle relaxants and five (23.8%) were intubated. CONCLUSIONS: In the largest single-institution study to date of laryngospasm in pediatric patients, we found a rate of 1/1000 cases. Treatment followed a basic algorithm comprising continuous positive airway pressure, deepening of anesthesia, muscle relaxation and tracheal intubation.

Vocal cord dysfunction/paradoxical vocal fold motion.

Vocal cord dysfunction, also called paradoxical vocal cord motion, is a common mimicker of asthma, allergies, and severe upper airways obstruction with consequent misdiagnosis and mismanagement, and is frequently overlooked. Unfortunately, there is no unified understanding of this disorder, nor is there any consensus on its evaluation, etiology, or treatment. This article reviews the literature regarding the pathophysiology, causes, diagnosis, and treatment for this common disorder.