Gastrointestinal tissue as a "new" target of pollution exposure.

Airborne pollution has become a leading cause of global death in industrialized cities and the exposure to environmental pollutants has been demonstrated to have adverse effects on human health. Among the pollutants, particulate matter (PM) is one of the most toxic and although its exposure has been more commonly correlated with respiratory diseases, gastrointestinal (GI) complications have also been reported as a consequence to PM exposure. Due to its composition, PM is able to exert on intestinal mucosa both direct damaging effects, (by reaching it either via direct ingestion of contaminated food and water or indirect inhalation and consequent macrophagic mucociliary clearance) and indirect ones via generation of systemic inflammation. The relationship between respiratory and GI conditions is well described by the lung-gut axis and more recently, has become even clearer during coronavirus disease 2019 (COVID-19) pandemic, when respiratory symptoms were associated with gastrointestinal conditions. This review aims at pointing out the mechanisms and the models used to evaluate PM induced GI tract damage.

Cuffed versus uncuffed tracheal tubes in a rabbit training model for establishing an emergency front-of-neck airway in infants: a prospective trial.

BACKGROUND: There is a paucity of evidence regarding the optimal type of tracheal tube to be advanced over a Frova catheter when performing a 'bougie' emergency front-of-neck airway (eFONA) technique in infants during a 'cannot intubate, cannot oxygenate' situation. METHODS: A prospective non-inferiority trial in a rabbit cadaver surgical tracheotomy model to assess the performance of the eFONA technique with an uncuffed 3.5 mm ID tracheal tube vs a cuffed 3.0 mm ID tracheal tube. Queried outcomes include success rate, performance time, and severe secondary airway injuries among tracheal tube types. RESULTS: In 60 tracheostomies performed by 30 participants, the overall success rate was 98%. Performance time was independent from tracheal tube choice (uncuffed: 61 s [95% confidence interval (CI), 52-76], cuffed: 64 s [95% CI, 55-79]; P = 0.82). No tracheal tube type was preferred in terms of usability by participants. The cuffed tracheal tube required increased force to be advanced over the Frova catheter and was associated with a risk ratio of 2.5 (95% CI, 0.53-11.9; number needed to harm, 10) for severe secondary airway injuries when compared with the uncuffed tracheal tube. CONCLUSION: In performing eFONA in the rabbit cadaver model, an ID 3.5 uncuffed is non-inferior to an ID 3.0 cuffed tracheal tube regarding performance time and preference by the operator. Greater force application to advance the cuffed tube over the Frova catheter and more severe airway injuries may argue for the standardised performance of the eFONA technique with a uncuffed tracheal tube in infants.

Herb pair of Ephedrae Herba-Armeniacae Semen Amarum alleviates airway injury in asthmatic rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Ephedrae Herba (EH, Ephedra sinica Stapf.) and Armeniacae Semen Amarum (ASA, Prunus armeniaca L. var. ansu Maxim.) have been used to treat asthma, cold, fever, and cough in China for thousands of years. AIM OF THE STUDY: In this study, we aimed to investigate the optimal ratio of EH and ASA compatibility (EAC) to reduce airway injury in asthmatic rats and its possible mechanism. METHODS: Rats were sensitized with a mixture of acetylcholine chloride and histamine bisphosphate 1 h before sensitization by intragastric administration of EAC or dexamethasone or saline for 7 days. Subsequently, the ultrastructure of rat airway epithelial tissue changes, apoptosis of the airway epithelial cells, and the expression of mRNA and protein of EGRF and Bcl-2 were detected. RESULTS: Transmission electron microscope: EAC (groups C and E) had the most prominent effect on repairing airway epithelial cells' ultrastructural changes in asthmatic rats. TUNEL: dexamethasone and EAC (groups B、C、E and F) inhibited the apoptosis of airway epithelial cells in asthmatic rats (P < 0.05). In situ hybridization: EAC (group E) inhibited the overexpression of EGFR and Bcl-2 mRNA (P < 0.05).Western Blotting: EAC (groups A、B、C、E and F) inhibited the upregulation of airway epithelial EGFR and Bcl-2 protein expression (P < 0.01). CONCLUSIONS: Our findings indicate that EAC can inhibit abnormal changes in airway epithelial structure and apoptosis of airway epithelial cells, thereby alleviating airway injury. In this study, the best combination of EH and ASA to alleviate airway epithelial injury in asthmatic rats was group E (EH: ASA = 8: 4.5).

Airway Rupture Caused by Double-Lumen Tubes: A Review of 187 Cases.

The double-lumen tubes (DLTs) are the most widely used devices to provide perioperative lung isolation. Airway rupture is a rare but life-threatening complication of DLTs. The primary aim of this review was to collect all cases reported in the literature about airway rupture caused by DLTs and to describe the reported possible contributors, diagnosis, treatment, and outcomes of this complication. Another aim of this review was to assess the possible factors associated with mortality after airway rupture by DLTs. A comprehensive literature search for all cases of airway rupture caused by DLTs was performed in the PubMed, EMBASE, Ovid, Wanfang Database, and CNKI. The extracted data included age, sex, height, weight, type of operation, type and size of DLT, site of airway rupture, possible contributors, clinical presentation, diagnosis timing, treatment, and outcome. We included 105 single case reports and 22 case series with a total number of 187 patients. Most of the ruptures were in the trachea (n = 98, 52.4%) and left main bronchus (n = 70, 37.4%). The common possible contributors include use of a stylet, cuff overdistention, multiple attempts to adjust the position of a DLT, difficult intubation, and use of an oversized DLT. Most of the airway ruptures were diagnosed intraoperatively (n = 138, 82.7%). Pneumomediastinum, air leakage, hypoxemia, and subcutaneous emphysema were the common clinical manifestations. Most patients were treated with surgical repair (n = 147, 78.6%). The mortality of the patients with airway rupture by DLTs was 8.8%. Age, sex, site of rupture, diagnosis timing, and method of treatment were not found to be associated with mortality.

Increased Ratio of Dead Space to Tidal Volume in Subjects With Inhalation Injury.

BACKGROUND: Inhalation injury increases morbidity and mortality in burn patients. Patients with inhalation injury present with large differences between end-tidal CO2 pressure and [Formula: see text], an indirect measure of dead space. We aimed to investigate the relationships between increased dead space and inhalation injury outcomes. METHODS: This retrospective study included 51 adult subjects with burns and inhalation injuries. Demographics, size of burns, length of stay, ventilator days, blood gas results, end-tidal CO2 pressure, presence of ventilator-associated pneumonia, and mortality data were collected. Modified Baux scores and ratios of alveolar dead space to alveolar tidal volume ([Formula: see text]/[Formula: see text]) were calculated. Independent t tests were used to compare mean [Formula: see text]/[Formula: see text] of survivors to that of subjects who died and between subjects with and without pneumonia. The relationships between [Formula: see text]/[Formula: see text] and ventilator days or modified Baux score were assessed with bivariate correlation analysis. RESULTS: Our population had a mean age of 52 y and an average burn size of 17.5%. The average length of stay and ventilator days were 12 d and 3.8 d, respectively. The mean modified Baux score was 87. The mean [Formula: see text]/[Formula: see text] was 0.38. Ten subjects died, and 6 subjects had pneumonia. The [Formula: see text]/[Formula: see text] of survivors was significantly smaller for survivors than for subjects who died (0.34 vs 0.52, P = .03). No significant difference was observed between subjects with and without pneumonia (0.36 vs 0.47, P = .26). [Formula: see text]/[Formula: see text] correlated significantly with modified Baux score (r = .524, P < .001). CONCLUSIONS: Alveolar dead space ([Formula: see text]/[Formula: see text]) is easily calculated from [Formula: see text] and end-tidal CO2 pressure and may be useful in assessing severity of inhalation injury, the patient's prognosis, and the patient's response to treatment.

Traumatic Airway Injuries: Role of Imaging.

Airway Injuries are rare but often immediately life threatening. Incidence ranges from 0.5-2 % in blunt and 1-6 % in penetrating trauma. Upper airway injuries (UAI) are often clinically apparent and get shunted during the primary survey in the emergency department. Few UAI and majority of lower airway injuries (LAI) are occult on primary survey and need a high suspicion index. Clinically, the diagnosis of tracheobronchial injury is delayed in many patients because the airway column is maintained by the peribronchial tissue. Imaging in the form of MDCT, in conjunction with endoscopy, plays a role in delineating the exact site and extent of injury and ruling out associated vascular and esophageal injuries for definitive management of UAI. Chest radiographs and ultrasonography help raise suspicion of LAI by detection of pneumomediastinum, persistent pneumothorax and/or subcutaneous emphysema and should be followed up with multidetector computed tomography (MDCT) which is the mainstay of diagnosis. However, it requires careful evaluation of the airway tract and a thorough knowledge about the mechanism of trauma for detection of subtle injuries. Reconstructions in multiple planes and use of various post-processing techniques including minimum intensity projection (MinIP) images enhance the detection rate. The specific signs of LAI on CT include discontinuity in the tracheobronchial tree, focal intimal flap projecting in the lumen, focal soft tissue attached to the tracheal/bronchial wall, complete cut off of the bronchus/trachea and the fallen lung sign. We, hereby, illustrate the imaging spectrum of traumatic airway injuries in detail and discuss their management implications.

Safety and Costs of Endobronchial Ultrasound-Guided Nodal Aspiration and Mediastinoscopy.

BACKGROUND: There remains debate over the best invasive diagnostic modality for mediastinal nodal evaluation. Prior studies have limited generalizability and insufficient power to detect differences in rare adverse events. We compared the risks and costs of endobronchial ultrasound (EBUS)-guided nodal aspiration and mediastinoscopy performed for any indication in a large national cohort. METHODS: We conducted a retrospective study (2007-2015) with MarketScan, a claims database of individuals with employer-provided insurance in the United States. Patients who underwent multimodality mediastinal evaluation (n = 1,396) or same-day pulmonary resection (n = 2,130) were excluded. Regression models were used to evaluate associations between diagnostic modalities and risks and costs while adjusting for patient characteristics, year, concomitant bronchoscopic procedures, and lung cancer diagnosis. RESULTS: Among 30,570 patients, 49% underwent EBUS. Severe adverse events-pneumothorax, hemothorax, airway/vascular injuries, or death-were rare and invariant between EBUS and mediastinoscopy (0.3% vs 0.4%; P = .189). The rate of vocal cord paralysis was lower for EBUS (1.4% vs 2.2%; P < .001). EBUS was associated with a lower adjusted risk of severe adverse events (OR, 0.42; 95% CI, 0.32-0.55) and vocal cord paralysis (OR, 0.57; 95% CI, 0.54-0.60). The mean cost of EBUS was $2,211 less than mediastinoscopy ($6,816 vs $9,023; P < .001). After adjustment this difference decreased to $1,650 (95% CI, $1,525-$1,776). CONCLUSIONS: When performed as isolated procedures, EBUS is associated with lower risks and costs compared with mediastinoscopy. Future studies comparing the effectiveness of EBUS vs mediastinoscopy in the community at large will help determine which procedure is superior or if trade-offs exist.

Pneumomediastinum in blunt trauma: If aerodigestive injury is not seen on CT, invasive workup is not indicated.

BACKGROUND: Pneumomediastinum following blunt trauma is often observed on CT imaging, and concern for associated aerodigestive injury often prompts endoscopy and/or fluoroscopy. In recent years, adoption of multi-detector CT technology has resulted in high resolution images that may clearly identify aerodigestive injuries. The purpose of this study was to evaluate the utility of multi-detector CT in the identification of blunt aerodigestive injuries. METHODS: Over five years, patients with pneumomediastinum following blunt trauma were identified from the registry of a level 1 trauma center. All CT imaging of trauma patients during this time period was accomplished with 64-slice scanners. RESULTS: 127 patients with blunt traumatic pneumomediastinum were identified. Five airway injuries were identified, and all injuries were evident on CT imaging. No patient was found to have airway injury by endoscopy that was not evident on CT. No patient had an esophageal injury. CONCLUSION: Multi-detector CT imaging identifies aerodigestive injuries associated with pneumomediastinum following blunt trauma. The absence of a recognizable aerodigestive injury by CT effectively rules out the presence of such injury.

Oropharyngeal Injury From Spontaneous Combustion of a Lithium-ion Battery: A Case Report.

Lithium-ion batteries have been used for more than 20 years, most recently to power handheld devices including cellphones and electronic nicotine-delivery systems. They have garnered significant media attention due to thermal-related injuries occurring after spontaneous combustion. Spontaneous combustion of a lithium-ion battery occurs due to a process that is referred to as the thermal runaway effect. Here, we review the case of a 25-year-old female with severe oropharyngeal and upper aerodigestive thermal injuries after spontaneous combustion of a lithium-ion battery in a flashlight. We discuss the associated management and provide a review of the literature detailing similar injuries. Laryngoscope, 129:45-48, 2019.

National estimations of airway foreign bodies in children in the United States, 2000 to 2009.

OBJECTIVE: Identify risk factors associated with airway foreign bodies in children in the United States and report observed trends over time. DATA SOURCE: KID database (2000-2009). METHODS: ICD-9-CM codes for airway foreign bodies were used to identify patients. Risk factors were used for univariate analysis and a multivariate model to identify any increased risk of mortality. These factors were then also trended over time. RESULTS: Children with airway foreign bodies demonstrate similar risk factors as previously reported, such as male gender, age less than five years and lack of private insurance. The weighted mortality rate for paediatric inpatients with airway foreign bodies was about 2.75%. Fortunately, the rate remained relatively unchanged from 2000 to 2009. Geographically, urban hospital settings appeared to be more affected. Increased risks of mortality were noted for older age, urban hospital setting and teaching hospital status. CONCLUSIONS: Our findings confirm previous findings and identified that the diagnosis of airway foreign bodies in children were associated with male gender, age <5 years, lack of private insurance and geographic location in an urban setting. Further investigation may be warranted to provide clarity on other factors found to have increased association with mortality for quality improvement.

Lesões pulmonares em suínos abatidos no matadouro Público Municipal de Esperança, Paraíba / Pulmonary lesions of slaughtered pigs at the municipal public slaughterhouse of Esperança, Paraíba

O objetivo do presente estudo foi avaliar as lesões macroscópicas e histológicas em pulmões de suínos abatidos no abatedouro público de Esperança, Paraíba. Foram inspecionados pulmões de 180 suínos entre julho e dezembro de 2013. Destes, 34 (18,8%) apresentaram lesões. Na análise anatomopatológica dos fragmentos coletados, 82,3% (28/34) exibiram lesões sugestivas de Pneumonia Enzoótica Suína (PES). Seis (17,7%) amostras apresentaram alterações causadas pela distribuição irregular de sangue. Casos sugestivos de PES crônica foram observados em 57,1% (16/28) dos fragmentos coletados. Em 42,9% (12/28) das amostras foram definidos como sugestivos de PES subaguda. Nenhum pulmão apresentou lesões sugestivas de PES aguda. A pesquisa demonstrou que lesões pulmonares em suínos são frequentemente detectadas no abatedouro de Esperança, Paraíba, sendo a maioria destas lesões sugestivas de PES.

The objective of the present study was to evaluate the macroscopic and histological lesions in the lungs of slaughtered pigs at the public slaughterhouse of Esperança, Paraíba. Lungs from 180 pigs were inspected between July and December 2013. Lesions were observed in 34 (18.8%) lungs. In the anatomopathological analysis of the collected fragments, 82.3% (28/34) presented suggestive lesions of Swine Enzootic Pneumonia (SEP). Six (17.7%) samples presented alterations caused by irregular blood distribution. Suggestive cases of chronic SEP were observed in 57.1% (16/28) of the collected fragments. In 42.9% (12/28) of the samples were defined as suggestive of subacute SEP. No lungs presented lesions suggestive of acute PES. The research showed that lung lesions in pigs are frequently detected in the Esperança, Paraíba slaughterhouse, with the majority of these lesions suggestive for SEP.

Protocol incorporating airway CT decreases negative bronchoscopy rates for suspected foreign bodies in pediatric patients.

BACKGROUND: Foreign body aspiration (FBA) is the 4th leading cause of death in children between the ages 1-5. Although direct laryngoscopy and bronchoscopy (DL&B) is the reference standard for diagnosis of pediatric airway foreign bodies, there is a high negative bronchoscopy rate, exposing patients to unnecessary operative and anesthetic risks and costs. METHODS: A clinical care protocol entailing the selective use of low-dose non-contrast airway computed tomography (CT) for children with an intermediate risk for FBA on the basis of clinical exam and chest radiography was implemented to decrease the negative DL&B rate. A retrospective review was conducted to compare negative bronchoscopy rates before and after implementation of the new protocol and the diagnostic performance characteristics of airway CT for airway foreign bodies were analyzed. RESULTS: After implementation of the airway FB clinical care protocol entailing selective airway CT, the overall negative bronchoscopy rate decreased from an institutional historical rate of 37% (54/145) to 17% (10/56) (p = .06). The overall sensitivity, specificity, and positive and negative predictive value of airway CT for FB was 91%, 100%, 100%, and 97% respectively. CONCLUSIONS: Low-dose non-contrast airway CT is highly sensitive and specific for airway foreign bodies, and its selective use in a clinical care protocol for children with suspected foreign body aspiration could greatly reduce the negative bronchoscopy rate, thereby decreasing operative risks and costs.

Predictors of complicated airway foreign body extraction.

OBJECTIVES: To evaluate outcomes of foreign body aspiration (FBA) and to investigate surgeon and hospital volume as risk factors for a complicated course. STUDY DESIGN: Retrospective case series. METHODS: Children with FBA in a multihospital network were identified from January 2005 to September 2015. Demographic information, surgeon, and hospital location were reviewed. Mean operative time and hospital length of stay were recorded. Cases requiring intensive care unit admission, hospital stay greater than 24 hours, need for more than one bronchoscopy, operative time greater than 1 hour, or death were considered "complicated." RESULTS: A total of 450 cases of airway foreign body extraction were performed. Patient ages ranged from 0.6 to 18.8 years, with a median age of 1.9 years. Bronchoscopy with foreign body extraction was performed by 55 different surgeons at 11 different facilities. There were one to 24 surgeons for each facility, with an average number of 5.4 surgeons per facility. A total of 88 (19.6%) cases were considered complicated, including five (1.1%) deaths. Increased rates of complications were seen with unwitnessed aspiration (P = 0.008) and hyperlucency (P < 0.001) or infiltrates (P = 0.001) on chest radiographs. No significant association was found between surgeon type or facility as related to a complicated case. CONCLUSIONS: Unwitnessed aspiration events and abnormalities on chest radiograph may be associated with a more complicated course in children with FBA. This multihospital study identified a low number of procedures by many surgeons; however, surgeon and hospital volume did not significantly correlate with higher complication rates. LEVEL OF EVIDENCE: 4. Laryngoscope, 128:490-495, 2018.

Low rate of positive bronchoscopy for suspected foreign body aspiration in infants.

OBJECTIVES: To describe our institution's low rate of positive bronchoscopy in infants suspected of inhaling a foreign body. STUDY DESIGN: Retrospective chart review. METHODS: A retrospective review was performed of patients at a tertiary children's hospital with suspected inhalation of a foreign body. Charts were reviewed for demographic information, radiologic findings, operative reports, and respiratory viral panels were reviewed. RESULTS: Sixteen pediatric patients under 12 months of age were identified from 2008 to 2016 with a diagnosis of possible airway foreign body inhalation who underwent emergent bronchoscopy. Of these patients, only one was positive for a foreign body present in the airway. The remaining 15 children were found to have a negative direct laryngoscopy and bronchoscopy evaluation for a foreign body. Of these fifteen patients, 14 were found to have structural airway abnormalities and 7 tested positive for a respiratory viral infection. CONCLUSIONS: Our institution has a low rate of positive bronchoscopy for highly suspected foreign body inhalation in a group of patients less than 12 months of age. Patients presenting with respiratory distress, stridor, or other airway symptoms were often found to have an underlying airway abnormality or viral infection, which coupled with an unclear history, would increase the suspicion for an airway foreign body and subsequent decision to perform bronchoscopy. In stable patients, diagnostic evaluation for an underlying respiratory infection should be performed in these cases. LEVEL OF EVIDENCE: Case Series.

The multivariate analysis of indications of rigid bronchoscopy in suspected foreign body aspiration.

OBJECTIVE: Foreign body aspiration (FBA) could be a serious life-threatening condition in children. Patients usually underwent bronchoscopy with suspicious of FBA alone. In this study, we aimed to determine which patients need to go to bronchoscopy based on pre-operative findings. METHODS: Retrospective analysis of patients underwent bronchoscopy between 1999 and 2015 was performed. Clinical symptoms, witnessed aspiration event (WAE), physical examination findings (PEFs) and radiological findings (RFs) were analyzed by multivariate analysis to evaluate the indications of bronchoscopy. RESULTS: 431 patients (266M, 165F) underwent bronchoscopy with a median age of 2 years (7 months-16 years). A foreign body was detected in 68% of the patients. Univariate analysis demonstrated that wheeze was the sole distinctive clinical symptom for detection of FBA (p<0.001). The rates of positive WAE, PEFs and RFs were 83%, 71.7% and 36.9%, respectively. All of them were identified as independent predictive parameters in the detection of FBA by univariate analysis (p = 0.003&p<0.001&p = 0.015). Multivariate analysis was performed with considering the association between them. The rate of positive bronchoscopy was 91.3% in patients with positive WAE, PEFs and RFs together(84/92). In patients with a positive WAE alone who had not got PEFs and RFs, the rate of positive bronchoscopy was 34.2% (25/73). A foreign body was detected in 84% of the patients who had not got a WAE but positive PEFs and RFs together(21/25). Bronchial laceration was occurred in one patient during bronchoscopy. Pneumothorax was not seen in any of the other patients. The rate of mortality was 0.4% in the overall group (2 patients). CONCLUSION: The indications of bronchoscopy in suspected FBA are usually based on clinical suspicious. The definition of " suspicous" could be a WAE or positive PEFs and RFs. The association of these factors increase the rate of positive bronchoscopies. In the light of our study, the classical indication for suspected FBA is still valid as "suspicious requires bronchoscopy".

Retrieval of tracheobronchial foreign bodies by short flexible endoscopy in children.

OBJECTIVES: Flexible endoscopy (FE) is frequently used to diagnose tracheobronchial foreign bodies (TBFB). However, it is still controversial for retrieval of TBFB in pediatric field. This study aims at reporting and evaluating our experiences of using short-length FE with a non-invasive ventilation (NIV) technique and intensive care unit (ICU) support in retrieving pediatric TBFB. METHODS: A retrospective review of the hospital database and FE videos of pediatric patients aged less than 18 year-old who were diagnosed of TBFB and managed in our hospital over a 17-year period (1999-2015). The demographic data were collected and analyzed. A NIV technique of providing nasopharyngeal oxygen with intermittent nose closure and abdominal compression was routinely performed in procedural sedated patients throughout the whole FE procedures. RESULTS: Sixty-six consecutive patients with 76 TBFB were enrolled. Among them, 72 (94.7%) TBFB in 64 patients were successfully retrieved at the first attempt of FE immediately after the diagnosis was made. There were 13 iatrogenic TBFB in patients who already had coexisting airway problems. The median age was 16 months (range 1.5 months-17 years) and the median body weight was 10.5 kg (range 3.5-48.5 kg). Seventy (70/72, 97.2%) TBFB were retrieved by short-length FE and among them, 55 procedures (55/72, 76.4%) used FE with no working channel. No significant acute or late adverse effects were noted. The mean retrieval procedural time was 23.6 ± 15.1 min. CONCLUSION: Using short-length FE with this NIV technique, appropriate sedation and ICU support is a safe, simple and effective modality for the retrieval of TBFB immediately after confirming the diagnosis in pediatric patients.

[INJURY PREVENTION WHILE ENSURING THE AIRWAY DURING SURGERY IN THE NOSE AND SINUSES.]

THE AIM: A comparative analysis of the injuries of upper airways flexible reinforced laryngeal mask and endotracheal intubation by examining the stress response reaction of the cardiovascular system, as well as the frequency and variety of complications. Blood pressure, heart rate, glucose and cortisol, and complications of airway management in children were analyzed. METHODS: The influence of the method of airway management with surgery in nose and sinuses in children in the stress response, hemodynamics, injuries of the airway were studied. The study included 140 patients aged 3 to 17 years. RESULTS: LMA FlexibleTMhas a minimal negative impact on the hemodynamics. Stress response is less pronounced when installing laryngeal mask than with tracheal intubation, which manifests itself in less cortisol concentration of 3.7%, 11.4% glucose. After removing the flexible reinforced laryngeal mask less than after extubation occurs: cough by 21%, 10% hoarseness, and sore throat by 26%. CONCLUSION: The use of the laryngeal mask airway during surgery in the nose and paranasal sinuses safer and less trau- matic manipulation compared with tracheal intubation.