The role of respiratory function tests in infants with stridor: diagnosis at glance and follow-up.

BACKGROUND: Recently, the development of advanced, noninvasive methods has allowed the study of respiratory function even in uncooperative infants. To date, there is still little data on the application of this technique in infants with suspected airway obstruction. THE AIMS OF OUR STUDY WERE: - To evaluate the role of respiratory function testing (PFR) in the diagnosis and follow-up of infants with stridor - To evaluate the differences between patients with inspiratory stridor and expiratory stridor. - To evaluate the concordance between PFR and endoscopy. METHODS: We enrolled infants aged < 1 year with a diagnosis of inspiratory and/or expiratory chronic stridor and a group of healthy controls. For each patient we performed PFR at diagnosis (T0) and for cases at follow-up, at 3 months (T1), 6 months (T2), 12 months (T3). At T0, all patients were classified according to a clinical score, and at follow-up, stature-ponderal growth was assessed. When clinically indicated, patients underwent bronchoscopy. RESULTS: We enrolled 48 cases (42 diagnosed with inspiratory stridor and 6 expiratory stridor) and 26 healthy controls. At T0, patients with stridor had increased inspiratory time (p < 0.0001) and expiratory time (p < 0.001) than healthy controls and abnormal curve morphology depending on the type of stridor. At T0, patients with expiratory stridor had a reduced Peak expiratory flow (p < 0.023) and a longer expiratory time (p < 0.004) than patients with inspiratory stridor. We showed an excellent concordance between PFR and endoscopic examination (k = 0.885, p < 0.0001). At follow-up, we showed a progressive increase of the respiratory parameters in line with the growth. CONCLUSIONS: PFR could help improve the management of these patients through rapid and noninvasive diagnosis, careful monitoring, and early detection of those most at risk.

Neural network analysis of pharyngeal sounds can detect obstructive upper respiratory disease in brachycephalic dogs.

Brachycephalic obstructive airway syndrome (BOAS) is a highly prevalent respiratory disease affecting popular short-faced dog breeds such as Pugs and French bulldogs. BOAS causes significant morbidity, leading to poor exercise tolerance, sleep disorders and a shortened lifespan. Despite its severity, the disease is commonly missed by owners or disregarded by veterinary practitioners. A key clinical sign of BOAS is stertor, a low-frequency snoring sound. In recent years, a functional grading scheme has been introduced to semi-objectively grade BOAS based on the presence of stertor and other abnormal signs. However, correctly grading stertor requires significant experience and adding an objective component would aid accuracy and repeatability. This study proposes a recurrent neural network model to automatically detect and grade stertor in laryngeal electronic stethoscope recordings. The model is developed using a novel dataset of 665 labelled recordings taken from 341 dogs with diverse BOAS clinical signs. Evaluated via nested cross validation, the neural network predicts the presence of clinically significant BOAS with an area under the receiving operating characteristic of 0.85, an operating sensitivity of 71% and a specificity of 86%. The algorithm could enable widespread screening for BOAS to be conducted by both owners and veterinarians, improving treatment and breeding decisions.

Bronquitis plástica. Caso clínico interesante / Plastic Bronchitis. Interesting Case Report

La bronquitis plástica es una enfermedad infrecuente y poco estudiada. Se caracteriza por la obstrucción parcial o total de la vía aérea inferior por moldes o yesos gomosos y firmes, compuestos por múltiples sustancias como fibrina, mucina y otros, que se acumulan en la luz bronquial. En la actualidad, no hay un consenso de la fisiopatología real. Puede presentarse con síntomas leves como tos, sibilancias y disnea, hasta eventos fatales de insuficiencia respiratoria. Se clasifican en tipo I (inflamatorios) y tipo II (acelulares). La presencia de la bronquitis plástica es una complicación de varias enfermedades y está relacionada con procedimientos correctivos de cardiopatías congénitas (procedimiento de Fontan). El diagnóstico se hace a través de la identificación de los yesos bronquiales, ya sea cuando el paciente los expectora o por broncoscopía. Se han utilizado múltiples terapias que solo tienen evidencias anecdóticas. En los últimos años se han observado buenos resultados con el uso de heparinas, así como el alteplasa nebulizado e instilado por broncoscopia.

Plastic bronchitis is a rare and little-studied disease. It is characterized by partial or total obstruction of the lower airway by rubbery and firm molds or plasters, made up of multiple substances that accumulate in the bronchial lumen. Currently, there is no consensus on real pathophysiology. It can present itself with mild symptoms such as cough, wheezing and dyspnea, to fatal events of respiratory failure. They are classified into type I (inflammatory) and type II (acellular). The presence of plastic bronchitis is a complication of several diseases and in corrective procedures for congenital heart disease (Fontan procedure). Diagnosis is made by identifying bronchial casts, either by the patient expectorating them or by bronchoscopy. Multiple therapies have been used that only have anecdotal evidence. In recent years, good results have been observed with the use of heparins and tPA nebulized and instilled by bronchoscop.

Fractured Metallic Tracheostomy Tube: A Rare Presentation of Bronchial Foreign Body.

BACKGROUND: Tracheostomy is an important life-saving surgical procedure that could be used to secure the lower airway. It can however serve as a source of airway compromise when fragments from it are deposited. This condition must be diagnosed early enough, and appropriate intervention should be done to forestall potential morbidity and mortality. CASE REPORT: A 56-year-old tracheostomized patient presented to the accident and emergency department with a 4-hour history of sudden onset choking cough and labored breathing. The shaft of his tracheostomy tube (TT) was fractured and subsequently aspirated while he was attempting to remove and clean the inner tube that morning. He has used the TT for about 6 years and lost to follow-up clinic visits. The chest radiograph showed the metallic foreign body lodged within the trachea. He had an emergency rigid bronchoscopy via the tracheostomy stoma, and the object was retrieved. All respiratory symptoms subsequently resolved, and a check radiograph showed normal findings. CONCLUSION: Tracheostomy tube fracture and aspiration should be ruled out in every tracheostomized patient with sudden onset acute respiratory symptoms. Otolaryngologists must always emphasize the need for proper handling of TT, regular follow-up, and tube replacement when due.

Imaging studies in evaluating children with stridor. / Los estudios por imágenes en la evaluación del niño con estridor.

Stridor is a symptom of upper airway obstruction and may result from congenital or acquired causes. The diagnosis is usually clinical. If further investigation is necessary for differential diagnosis, endoscopy is the method of choice in most cases. Imaging studies are complementary to endoscopy. They allow evaluation of laryngeal and tracheobronchial pathology and extrinsic airway compressions due to tumors or vascular malformations and define a lesion's location, extent, and characteristics. They are helpful in cases of diagnostic doubt and when endoscopy is unavailable. It is essential to understand the anatomy and pathophysiology of the respiratory tract and to be aware of the indications and limitations of complementary examinations for proper diagnosis. The different imaging modalities available to evaluate stridor in pediatrics are described, and their advantages are discussed.

El estridor es un síntoma de obstrucción de la vía aérea superior y puede ser resultado de causas congénitas o adquiridas. El diagnóstico suele ser clínico. Si es necesaria una investigación adicional para el diagnóstico diferencial, la endoscopia es el método de elección en la mayoría de los casos. Los estudios por imágenes son complementarios a la endoscopia. Permiten evaluar la patología laríngea y traqueobronquial, las compresiones extrínsecas de la vía aérea por tumores o malformaciones vasculares y definir la localización, extensión y características de una lesión. Son útiles en casos de duda diagnóstica y cuando la endoscopia no está disponible. Es fundamental comprender la anatomía y fisiopatología del tracto respiratorio, y ser conscientes de las indicaciones y limitaciones de los exámenes complementarios para el diagnóstico adecuado. Se describen las diferentes modalidades de imágenes disponibles para evaluar el estridor en pediatría y se discuten sus ventajas.

A Comparison of Drug-Induced Sleep Endoscopy Findings in Infants and Toddlers.

OBJECTIVE: To compare patterns of obstruction in infants and toddlers with obstructive sleep apnea (OSA) by analyzing drug-induced sleep endoscopy (DISE) examinations. STUDY DESIGN: Retrospective chart review. SETTING: An academic tertiary care pediatric hospital at a single institution. METHODS: Children aged ≤3 years who underwent DISE with propofol titration from 2020 to 2022 were included in the study. Data extracted included age, body mass index, comorbidities, and polysomnography parameters. The sites of anatomic obstruction during DISE were recorded using a validated 10-site scoring system. RESULTS: A total of 86 children underwent DISE, including 15 infants (<1 year) and 71 toddlers (>1≤3 years). Sixty-two percent were male and 37% were female. The mean age of the infant group was 9.6 months (95% confidence interval [CI]: 7.92, 11.28 months), and the mean age of the toddler group was 2.3 years (95% CI: 2.06, 2.50 years). The mean total number of sites of obstruction was not significantly different between infants (N = 2.5) and toddlers (N = 3.2, P = .086). The most common subsite of significant obstruction in both infants and toddlers was the aryepiglottic folds (46.7% and 36.8%, respectively; P = .578). The sites of obstruction and frequency of their occurrence were not significantly different between the 2 groups. CONCLUSION: Multisite airway obstruction is common among children with OSA, especially at the epiglottis, aryepiglottic folds, and tongue base. There is no difference in sites of obstruction and their frequency between toddlers and infants.

Effects of Exercise-Induced Laryngeal Obstruction in Adolescents: A Qualitative Study.

PURPOSE: The purpose of this study was to examine the influence of exercise-induced laryngeal obstruction (EILO) on adolescents. METHOD: Twenty patients (< 17 years) diagnosed with EILO participated in this study. Patients completed semistructured interviews examining their experience with the health care system, treatment, and the effects of EILO symptoms on quality of life. Interviews were analyzed using a combination of directed and conventional content analyses. Researchers identified seven overarching themes either prior to or during analysis, and 24 subthemes were inductively identified from patient interviews using open, axial, and selective coding. RESULTS: On average, patients went 1.9 years between symptom onset and EILO diagnosis. Patients described symptom onset as frightening and confusing. Even after initially reporting symptoms to a medical provider, patients went an average of 10.5 months before diagnosis. Patients perceived that delays in diagnosis prevented efficient management and allowed symptoms to escalate. Patients reported that EILO detrimentally influenced athletic performance, forcing them to pace themselves or cease participation altogether. Social and academic effects of EILO included missed classes, difficulty in physical education courses, and resentment from teammates if athletic performance declined. Both athletes and nonathletes indicated that EILO elicited feelings of fear, frustration, dread, guilt, and embarrassment. Patients reported that therapy with a speech-language pathologist (SLP) effectively addressed symptoms; however, employing rescue breathing techniques was often more difficult than anticipated. CONCLUSIONS: Physical and emotional sequelae associated with EILO may have widespread influence on patient quality of life. Therapy with an SLP reportedly ameliorated EILO symptoms; however, patients indicated that delayed diagnosis allowed negative effects to intensify prior to treatment.

Acute Airway Obstruction: An Unusual Presentation of Posttransplant Lymphoproliferative Disorder in a Renal Transplant Recipient.

Posttransplant lymphoproliferative disorder is a life-threatening complication after solid-organ transplants. In adults, recipients of heart transplants have the highest risk, whereas renal transplant recipients have the lowest risk among all solid-organ transplants. The most common site for posttransplant lymphoproliferative disorders are gastrointestinal tract followed by the graft itself. Airway involvement in posttransplant lymphoproliferative disorder is rarely encountered. We report a case of a 26-year-old renal allograft recipient who presented to the emergency room with airway obstruction necessitating an emergency tracheostomy. Imaging revealed a left tonsillar mass extending into the nasopharynx and retropharyngeal space causing complete oropharyngeal occlusion. Endoscopic biopsy from nasopharyngeal mass showed a diffuse large B-cell lymphoma and was Ebstein-Barr virus positive. Reduction in immunosuppression and treatment with posttransplant lymphoproliferative disorder-1 risk-stratified approach resulted in complete remission.

Prevalence, stability, and clinical significance of an isolated low FEV1 spirometry pattern in children.

OBJECTIVES: In adults, an isolated low FEV1 pattern (an FEV1 below the lower limit of normal with a preserved FVC and FEV1/FVC) has been associated with the risk of developing airway obstruction. Our objective was to examine the prevalence, stability, and clinical significance of an isolated low FEV1 pattern in the pediatric population. METHODS: We conducted a retrospective study of spirometries from children ages 6-21 years and categorized tests into spirometry patterns according to published guidelines and recent literature. In a subgroup of tests with an isolated low FEV1 pattern, we evaluated spirometry technique. We also examined the association of having a test with an isolated low FEV1 pattern with clinical markers of disease severity in a subgroup of children with cystic fibrosis (CF). RESULTS: The isolated low FEV1 pattern was uncommon across the 29,979 tests included (n = 645 [2%]). In the 263 children with an isolated low FEV1 pattern who had a follow-up test performed, the most frequent spirometry pattern at last test was normal (n = 123 [47%]). A primary diagnosis of CF was associated with increased odds of having at least one test with an isolated low FEV1 pattern (OR = 8.37, 95% CI = 4.70-15.96, p < .001). The spirometry quality in a subgroup of tests with an isolated low FEV1 pattern (n = 50) was satisfactory. In the subgroup of children with CF (n = 102), those who had a test with an isolated low FEV1 pattern had higher odds of using oral antibiotics in the last 12 months than those who had a normal pattern (OR = 3.50, 95% CI = 1.15-10.63, p = .03). CONCLUSIONS: The isolated low FEV1 pattern can occur repeatedly over time, usually transitions to a normal pattern, is not due to a poor spirometry technique, and could be clinically relevant in children with chronic lung diseases.

Diagnostic and Therapeutic Role of Electrocautery Snare Use in Endobronchial Polypoid Lesions.

INTRODUCTION: Electrocautery with a snare probe offers a tool for the treatment of endobronchial polyps. The aim of this study was to demonstrate the efficacy of the snare probe in patients undergoing rigid bronchoscopy due to central airway obstruction. METHODS: This retrospective descriptive study included patients who underwent rigid bronchoscopy with an electrocautery snare probe for the diagnosis and/or treatment of endobronchial polyps in an interventional pulmonology unit. RESULTS: The mean age of the 47 patients (38 men) with endobronchial polypoid lesions was 61.5 years. Six lesions (12.8%) were located in the trachea, 6 (12.8%) in the right main bronchus, 11 (23.4%) in the left main bronchus, and 24 (51.1%) in the lobar bronchi. Twenty-eight lesions (59.5%) were malignant. Prior to the procedure, 6 (12.8%) patients had grade 1 obstruction, 6 (12.8%) had grade 2 obstruction, 15 (31.9%) had grade 3 obstruction, and 20 (42.6%) had grade 4 obstruction. In terms of airway obstruction after the procedure, grade 1 was present in 46 (97.9%) patients and grade 2 was present in 1 (2.1%) patient. No major complication developed in 93.6% of the patients. During a mean follow-up period of 48 months, 85.1% of the patients did not experience recurrence. CONCLUSION: Our results demonstrate that the snare probe can be used to effectively and reliably establish airway patency in patients with central airway obstruction due to endobronchial polypoid lesions.

Diagnostic utility of spirometry for children with induced laryngeal obstruction or chronic non-specific cough.

PURPOSE: To determine the diagnostic utility of spirometry in distinguishing children with Induced Laryngeal Obstruction (ILO) or chronic non-specific cough (a.k.a. tic cough) from those with mild or moderate to severe asthma. METHODS: Retrospective cross sectional design. Children diagnosed with ILO (N = 70), chronic non-specific cough (N = 70), mild asthma (N = 60), or moderate to severe asthma (N = 60) were identified from the electronic medical record of a large children's hospital. Spirometry was completed before ILO, non-specific cough, or asthma diagnoses were made by pediatric laryngologists or pulmonologists. Spirometry was performed following American Thoracic Society guidelines and was interpreted by a pediatric pulmonologist. Forced Vital Capacity (FVC), Forced Expiratory Volume in 1 Second (FEV1), FEV1/FVC Ratio (FEV1/FVC), Forced Mid-Expiratory Flow 25--75 % (FEF25-75%), pulmonologist interpretation of flow volume loops, and overall exam findings were extracted from the medical record. RESULTS: Ninety seven percent of children with ILO or chronic non-specific cough presented with spirometry values within normative range. Patients with ILO, non-specific cough, and mild asthma presented with FVC, FEV1, FEV1/FVC, and FEF25-75% values in statistically similar range. Children with moderate to severe asthma presented with significantly reduced FVC (p < .001), FEV1 (p < .001), FEV1/FVC (p < .001), and FEF25-75% (p < .001) values when compared with patients in the other groups. Flow volume loops were predominantly normal for children with ILO and non-specific cough. CONCLUSIONS: Findings indicate that ILO and chronic non-specific cough can neither be diagnosed nor differentiated from mild asthma using spirometry alone. Spirometry should therefore be used judiciously with this population, bearing in mind the limitations of the procedure. Future research should determine the most effective and efficient ways of delineating ILO and non-specific cough from other respiratory conditions in children.

Therapeutic bronchoscopy for malignant central airway obstruction: Introduction to the EpiGETIF registry.

BACKGROUND AND OBJECTIVE: EpiGETIF is a web-based, multicentre clinical database created in 2019 aiming for prospective collection of data regarding therapeutic rigid bronchoscopy (TB) for malignant central airway obstruction (MCAO). METHODS: Patients were enrolled into the registry from January 2019 to November 2022. Data were prospectively entered through a web-interface, using standardized definitions for each item. The objective of this first extraction of data was to describe the population and the techniques used among the included centres to target, facilitate and encourage further studies in TB. RESULTS: Overall, 2118 patients from 36 centres were included. Patients were on average 63.7 years old, mostly male and smokers. Most patients had a WHO score ≤2 (70.2%) and 39.6% required preoperative oxygen support, including mechanical ventilation in 6.7%. 62.4% had an already known histologic diagnosis but only 46.3% had received any oncologic treatment. Most tumours were bronchogenic (60.6%), causing mainly intrinsic or mixed obstruction (43.3% and 41.5%, respectively). Mechanical debulking was the most frequent technique (67.3%), while laser (9.8%) and cryo-recanalization (2.7%) use depended on local expertise. Stenting was required in 54.7%, silicone being the main type of stent used (55.3%). 96.3% of procedure results were considered at least partially successful, resulting in a mean 4.1 points decrease on the Borg scale of dyspnoea. Complications were noted in 10.9%. CONCLUSION: This study exposes a high volume of TB that could represent a good source of future studies given the dismal amount of data about the effects of TB in certain populations and situations.

Feasibility of Constant Work Rate Testing to Detect Exercise-Induced Laryngeal Obstruction.

INTRODUCTION: Exercise-induced laryngeal obstruction (EILO) is a condition in which laryngeal structures inappropriately obstruct the upper airway during exercise. The standard diagnostic test for EILO is the continuous laryngoscopy during exercise (CLE) test, usually performed with an incremental work rate protocol regardless of the nature of the triggering event. Typically, laryngeal obstruction occurs only briefly at the end of an incremental test, near peak work capacity. We aimed to investigate constant work rate (CWR) protocols for CLE testing to expand diagnostic test modalities and improve the understanding of EILO. METHODS: In this prospective, self-controlled feasibility study, 10 patients with EILO performed both an incremental and a CWR CLE test at 70%, 80%, and 90% of maximal exercise capacity. Laryngoscopic video data were recorded and compared, and we evaluated the ability of CWR to reproduce the symptoms and laryngeal obstruction seen in incremental testing. RESULTS: In 70%-90% of cases, CWR testing induced at least the same severity of obstruction as incremental testing and CLE scores remained comparable across test modalities. CWR at 70% allowed observation of laryngeal obstruction for a significantly longer duration than in incremental testing (158 s; 95% confidence interval, 25-291 s; P = 0.027). Dyspnea intensity appeared higher during CWR testing compared with incremental testing. CONCLUSIONS: Submaximal CWR CLE testing is feasible and able to induce EILO equivalent to the standard incremental CLE test. This is the first step toward tailored CLE exercise protocols, and further studies are now needed to establish the utility of CWR in clinical and research settings.

Are Questionnaires Helpful To Predict Exercise-Induced Bronchoconstriction (EIB) And Exercise-Induced Laryngeal Obstruction (EILO)?

OBJECTIVE: Exercise induced laryngeal obstruction (EILO) is an important differential diagnosis to exercise induced bronchoconstriction (EIB) and diagnosed via continuous laryngoscopy while exercising (CLE). However, availability of CLE is limited to specialized centres. And without CLE EILO is often misdiagnosed as EIB. Therefore it is essential to carefully preselect potential EILO candidates. Aim of this study was to investigate whether two short questionnaires -Asthma Control Test (ACT) and Dyspnea Index (DI) evaluating upper airway-related dyspnea- can differentiate between EIB and EILO. METHODS: Patients with dyspnea while exercising were analysed with an exercise challenge in the cold chamber (ECC) to diagnose EIB in visit 1 (V1), as appropriate a CLE in visit 2 (V2, 4-6 weeks after V1) and ACT and DI in V1 and V2. EIB patients were treated with asthma medication after V1. RESULTS: Complete dataset of 36 subjects were gathered. The ACT showed lower values in V2 in EILO compared to EIB patients. A lack of improvement in ACT in V2 after asthma medication of EIB patients is suspicious for additional EILO diagnosis. The DI showed higher values in V1 in EILO compared to EIB patients. A score≥30 can predict a positive CLE reaction. CONCLUSION: ACT and DI are valuable tools in preselecting CLE candidates to assure timely diagnostic despite limited diagnostic capabilities.

An update on diagnosis and management of obstructive sleep apnoea in the first 2†years of life.

The aim of this review is to summarise evidence that became available after publication of the 2017 European Respiratory Society statement on the diagnosis and management of obstructive sleep apnoea syndrome (OSAS) in 1- to 23-month-old children. The definition of OSAS in the first 2 years of life should probably differ from that applied in children older than 2 years. An obstructive apnoea-hypopnoea index >5 events·h-1 may be normal in neonates, as obstructive and central sleep apnoeas decline in frequency during infancy in otherwise healthy children and those with symptoms of upper airway obstruction. A combination of dynamic and fixed upper airway obstruction is commonly observed in this age group, and drug-induced sleep endoscopy may be useful in selecting the most appropriate surgical intervention. Adenotonsillectomy can improve nocturnal breathing in infants and young toddlers with OSAS, and isolated adenoidectomy can be efficacious particularly in children under 12 months of age. Laryngomalacia is a common cause of OSAS in young children and supraglottoplasty can provide improvement in children with moderate-to-severe upper airway obstruction. Children who are not candidates for surgery or have persistent OSAS post-operatively can be treated with positive airway pressure (PAP). High-flow nasal cannula may be offered to young children with persistent OSAS following surgery, as a bridge until definitive therapy or if they are PAP intolerant. In conclusion, management of OSAS in the first 2 years of life is unique and requires consideration of comorbidities and clinical presentation along with PSG results for treatment decisions, and a multidisciplinary approach to treatment with medical and otolaryngology teams.

Transtracheal Pressure for Evaluation of Decannulation Readiness.

BACKGROUND: Pediatric tracheostomy decannulation protocols vary among institutions and may include toleration of Passy Muir Valve (PMV), microlaryngoscopy and bronchoscopy (MLB) findings, and polysomnography evaluation. Transtracheal pressure (TTP) is an objective measurement utilized to evaluate PMV toleration. We aimed to investigate the role of TTP in decannulation candidates and compare TTP measurements with polysomnography and MLB findings. METHODS: A retrospective cohort study of children who underwent TTP measurement during PMV trial between December 2012 and November 2022. RESULTS: A total of 79 patients underwent TTP measurement and MLB evaluation; of these, 16 (20.3%) patients had a capped polysomnography. Twenty-eight (35.4%) patients had TTPs ≤10 cm H2O, and 51 (64.6%) patients had TTPs >10 cm H2O. The most common indication for tracheostomy was upper airway obstruction (n = 41, 51.9%), followed by a need for mechanical ventilation (n = 24, 30.4%). Twenty-five (31.6%) patients were decannulated. Patients with TTPs ≤10 cm H2O had a mean Apnea-Hypopnea Index of 0.17 ± 0.26/h compared with 6.93 ± 7.67/h in those with TTPs >10 cm H2O, p = 0.0365. Patients with TTPs >10 cm H2O were found to have a significantly higher occurrence of airway obstruction (96.1% vs. 46.4%, p < 0.0001) and multilevel airway obstruction (70.6% vs. 21.4%, p < 0.0001) on MLB. Neither TTP measured at time of PMV assessment nor capped polysomnography was associated with successful decannulation. CONCLUSIONS: TTP measurements at time of PMV evaluation are associated with polysomnography and MLB findings. One-time PMV measurements were not indicative of decannulation success. LEVEL OF EVIDENCE: 4 Laryngoscope, 134:3377-3383, 2024.

Risk Factors for Desaturation in Anesthetic Management During Airway Stenting.

Airway stenting involves a stent being inserted into a stenotic site in the airway. In patients with airway stenosis, the airway is the surgical field; therefore, anesthetic management is challenging, and avoiding hypoxia is important. Limited information is available on the anesthetic management of airway stenting. Risk factors for oxygen desaturation during airway stenting remain unknown. The present study was conducted to retrospectively examine patients who underwent airway stenting during a specific period and identify risk factors associated with oxygen desaturation. We performed univariate and multivariate analyses. The main evaluation items in a multivariate analysis were risk factors for desaturation (SpO2 ≤ 90%). Body mass index, preoperative orthopnea, the stenotic site of the airway, and severity of stenosis were selected for clinical usefulness. We analyzed 302 patients who underwent airway stenting at our hospital between July 2011 and June 2014 under general anesthesia with controlled ventilation. Total intravenous anesthesia with propofol target-controlled infusion and remifentanil was performed. Clinical data were extracted from electronic anesthetic records. The incidence of desaturation (SpO2 ≤ 90%) was 18.5% (56 out of 302 cases). Preoperative orthopnea (OR, 3.06)and stenosis distal to the bronchus (OR, 3.31) were identified as risk factors for desaturation in a multivariate analysis. We herein identified risk factors for desaturation during airway stenting. Anesthetic plans need to be carefully considered for patients with these risk factors.