Airway Occlusion Research Articles

Effects of sedation on clinical, gasometric, and respiratory muscle parameters in critically ill chronic obstructive pulmonary disease patients

BackgroundSevere chronic obstructive pulmonary disease (COPD) exacerbation requiring mechanical ventilation is commonly encountered in the ICU. Sedation is necessary to facilitate mechanical ventilation. The effect of no-sedation strategy on different patient parameters on the ventilator has not yet been well studied. The aim of this study was to test the efficacy of no-sedation protocol in controlling COPD patient’s gasometric and clinical parameters during mechanical ventilation.Patients and methodsPatients with COPD who required mechanical ventilation were randomized to either: sedated with daily interruption (control group) (n=50) or nonsedated group (n=47). The change in the partial pressure of arterial CO2 (PaCO2) was the primary outcome measure. Secondary outcome measures included: changes in pH, heart rate (HR), mean arterial blood pressure (MAP), respiratory rate, airway occlusion pressure (P0.1), and negative inspiratory force (NIF). Recordings for arterial blood gases, HR, MAP, and respiratory rate were performed as baseline at intubation, 1, 2, 12, 24, and 48h after intubation. NIF and P0.1 were recorded 48 h after intubation.ResultsNo significant difference was found in baseline recordings of PaCO2, pH, HR, MAP, and respiratory rate between the sedated and nonsedated groups. Further recordings of PaCO2 (P_1, P_2, P_3, and P_4<0.001, P_5=0.005), HR (P<0.001), and respiratory rate (P<0.001) were significantly higher in the nonsedated group. The rate of correction of pH from acidosis was faster among the sedated patients. MAP was significantly higher in nonsedated patients in recordings 2, 12, and 48 h after intubation (P_1=0.9, P_2<0.001, P_3<0.001, P_4=0.87, P_5<0.001). No significant difference was found in NIF or P0.1 between the two groups (P=0.8 and 0.1, respectively).ConclusionCOPD patients managed by no-sedation strategy had higher PaCO2, HR, MAP, and respiratory rate. No-sedation had no significant effect on respiratory muscle function when compared with daily interruption of sedation.

Dysregulation of Respiratory Center Drive (P0.1) and Muscle Strength in Patients With Early Stage Idiopathic Parkinson's Disease.

Objective: The goal of this study is to evaluate pulmonary function and respiratory center drive in patients with early-stage idiopathic Parkinson's disease (IPD) to facilitate early diagnosis of Parkinson's Disease (PD).Methods: 43 IPD patients (Hoehn and Yahr scale of 1) and 41 matched healthy individuals (e.g., age, sex, height, weight, BMI) were enrolled in this study. Motor status was evaluated using the Movement Disorders Society-Unified PD Rating Scale (MDS-UPDRS). Pulmonary function and respiratory center drive were measured using pulmonary function tests (PFT). All IPD patients were also subjected to a series of neuropsychological tests, including Non-Motor Symptoms Questionnaire (NMSQ), REM Sleep Behavior Disorder Screening Questionnaire (RBDSQ), Beck Depression Inventory (BDI) and Mini Mental State Examination (MMSE).Results: IPD patients and healthy individuals have similar forced vital capacity (FVC), forced expiratory volume in 1s (FEV1), forced expiratory volume in 1s/forced vital capacity (FEV1/FVC), peak expiratory flow (PEF), and carbon monoxide diffusion capacity (DLCOcSB). Reduced respiratory muscle strength, maximal inspiratory pressure (PImax) and maximal expiratory pressure (PEmax) was seen in IPD patients (p = 0.000 and p = 0.002, respectively). Importantly, the airway occlusion pressure after 0.1 s (P0.1) and respiratory center output were notably higher in IPD patients (p = 0.000) with a remarkable separation of measured values compared to healthy controls.Conclusion: Our findings suggest that abnormal pulmonary function is present in early stage IPD patients as evidenced by significant changes in PImax, PEmax, and P0.1. Most importantly, P0.1 may have the potential to assist with the identification of IPD in the early stage.

Neural Responses of the Cervical Sympathetic Chain to Barorecepter Activation and to Hypoxic Challenge in Sprague‐Dawley Rats

The superior cervical ganglion (SCG) and cervical sympathetic chain (CSC) contain cell bodies that project to the cerebral arteries, and to peripheral structures such as the carotid bodies and upper airways. Despite the importance of these pathways, little is known about how the CSC responds to baroreceptor stimuli and to hypoxic challenges that mimic upper airway obstruction and central apneas. To characterize sensory control of CSC activity, we anesthetized male Sprague‐Dawley rats (275–300g) with isoflurane (2%) and placed bipolar recording electrodes under the CSC at approximately 3 mm caudal to the SCG, and a blood pressure catheter into the left femoral artery (Telemetry Research, model TR56SP). A catheter was placed in the left femoral vein for intravenous (IV) injections. Heart rate, blood pressure (BP), and multi‐fiber CSC neural activity were recorded during 10% oxygen challenge, tracheal occlusion, and during IV drug administration. At the end of the protocol, the rats were euthanized to determine background noise activity. In on‐going studies (n = 4), we found that CSC recordings yielded typical sympathetic responses to phenlyephrine (2.5 μg) and sodium nitroprusside (2.5 μg). For phenyephrine, BP increased by 24 ± 5 mmHg with CSC decreases of 100% baseline to 69 ± 11%. For sodium nitroprusside, BP decreased by 26 ± 3 mmHg with CSC increases of 100% to 111 ± 14%. Ganglionic blockade with hexamethonium (10 mg/kg) decreased BP by 49 ± 2 mmHg and lowered CSC activity by 69 ± 8%. Temporary occlusion of the tracheal airway decreased BP by 16 ± 4 mmHg and increased CSC activity from 100% to 120 ± 17%. Finally, a 1 min 10% oxygen challenge lowered BP by 33 ± 9 mmHg but did not alter CSC activity (100% to 103 ± 5%). These findings indicate that the CSC, just caudal to the SCG, contains approximately 69% post‐ganglionic sympathetic nerve fibers. These nerve fibers respond appropriately to baroreceptor loading and unloading, and show increased activity to temporary upper airway occlusion.Support or Funding InformationThis work was supported in part by NIH award 3OT2OD023680‐01S2 and Galvani BioelectronicsThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Impact of Dietary Folate on Respiratory Recovery after Cervical SCI

While much is known regarding folate's role in neural development, little is known concerning its effects in the adult central nervous system (CNS), particularly following injury or trauma. There is some evidence that folate enhances spinal sensory axon regrowth into a peripheral nerve graft after dorsal column injury. Further, 6 weeks after thoracic spinal contusion, folate supplementation elicits small but significant improvements in locomotor function in rats. Although surveys of individuals with chronic spinal cord injury (SCI) report reduced dietary folate intake, the impact folate intake on functional recovery after SCI is not known. Since respiratory dysfunction is the leading cause of death after cervical SCI, we investigated the effects of folate supplementation and deprivation on respiratory motor function after spinal hemisection at C2 (C2Hx). We hypothesized that folate supplementation would improve, while folate deprivation would hinder breathing recovery after C2Hx. In adult male Sprague Dawley rats with C2Hx, we compared the effects of a: 1) normal diet (4mg/kg folate in chow), 2) normal diet with supplemental folate injections (80ug/kg/day), and 3) folate deprivation (0 mg/kg folate in chow). Animals received their respective diets beginning 1 month prior to injury, and continued through the study duration. Intraperitoneal folate injections in the supplemented group were initiated 3 days prior to C2Hx and continued daily for 2 weeks post‐injury. Bilateral diaphragm electromyography (EMG) recordings were made in urethane anesthetized spontaneously breathing rats at 2 and 8 weeks post‐injury during normoxia (arterial PO2 ~90mmHg, PCO2 ~45mmHg), maximal chemoreceptor stimulation (10.5% O2/7% CO2), spontaneous augmented breaths (sighs), and sustained airway occlusion (40 sec). We did not see any consistent folate effects on ipsilateral or contralateral diaphragm EMG function at either 2 or 8 weeks post injury (P&gt;0.05 for all). Sprouting of serotonergic projections near retrogradely labeled phrenic motoneurons were assessed via immunofluorescence, and quantification is in progress. Although we found no evidence that folate supplementation or deprivation impacts diaphragm function following C2Hx, this does not discount folate's potential role in mediating spinal respiratory motor plasticity or functional recovery in other models of CNS injury. For example, C2Hx severs all ipsilateral axons, with a &gt;1mm gap. Since axonal growth and synapse formation is an innately slow process, the duration of this study may not have been sufficient to observe functional recovery mediated via axonal regrowth. Further studies are needed to rule out any role for folate in functional recovery following cervical SCI.Support or Funding InformationMcKnight Brain Institute, NIH SPARC OT 2OD023854, K12 HD055929, NIH T32 HD043730 and HL69064This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Congenital diaphragmatic hernia and complete tracheal rings: The value of peri-operative ECMO

Abstract A full-term male prenatally diagnosed with left congenital diaphragmatic hernia (CDH) was intubated at birth and scheduled for elective repair. The pre-operative chest radiograph incidentally demonstrated tracheal narrowing and an intraoperative flexible bronchoscopy was performed, suggestive of impending airway occlusion secondary to complete tracheal rings. Given these findings, he was electively cannulated post-operatively to venoarterial extracorporeal membrane oxygenation (ECMO) for stabilization and tracheal repair. Post-operative day one, he underwent further characterization by computed tomography and was taken for slide tracheoplasty on ECMO support. Immediately following tracheal repair, he was decannulated from ECMO and was extubated to nasal CPAP two days after the slide tracheoplasty. This case highlights the rare association of tracheal anomalies associated with CDH and options for perioperative management, including the role of ECMO.

Three-step management of a newborn with a giant, highly vascularized, cervical teratoma: a case report

BackgroundA giant congenital cervical teratoma is often highly vascularized; thus, in addition to a life-threatening airway occlusion at birth it comprises a high risk for significant and lethal blood loss during resection. In the case presented, an endovascular embolization of the carotid artery that supplied a giant congenital cervical teratoma was done as part of a three-stage treatment soon after birth and contributed to an overall good outcome. Embolization in cases of cervical teratomas was not described previously.Case presentationWe present a case of a preterm newborn from a Sephardic jewish origin with a giant, highly vascularized, congenital cervical teratoma that was managed successfully in three stages: (1) delivery by an ex utero intrapartum treatment procedure after extensive preoperative planning and followed by tracheostomy, (2) endovascular embolization of the carotid artery that supplied the tumor in order to decrease blood loss during resection, and (3) complete surgical resection. The parents were involved in all the ethical and medical decisions, starting just after the cervical mass was diagnosed prenatally.ConclusionThe management of giant congenital cervical teratoma is often challenging from both a medical and ethical prospective. Meticulous perinatal planning and parents’ involvement is crucial. Endovascular embolization of the tumor feeding vessels can significantly improve the resection outcome and overall prognosis.

Histological, Ultrastructural, and Physiological Evaluation of a Rat Model of Obstructive Sleep Apnea Syndrome.

BackgroundPatients with obstructive sleep apnea syndrome (OSAS) are at an increased risk of cardiovascular disease. The aims of this study were to develop a rat model of OSAS and to validate the use of the model by investigating respiratory and cardiovascular physiological parameters and morphological changes by light microscopy and electron microscopy.Material/MethodsSixty 3-month-old Sprague-Dawley rats were assigned to the model group (n=30) and the control group (n=30). The rats in the OSAS model group were injected with 0.1 ml sodium hyaluronate solution into the upper respiratory tract at the junction between the hard and soft palate. After one month, the model and normal rats were compared using tests of respiratory and cardiac function, and histology and electron microscopy of the lung and cardiac tissue.ResultsIn the rat model of OSAS, airway obstruction resulted in the collapse of the upper airway. Tests of respiratory function showed that the oxygen partial pressure, oxygen concentration, and oxygen saturation in the model group were significantly lower when compared with the control group. In the model group, histology of the heart showed cardiac myocyte disarray, and electron microscopy showed vacuolar degeneration and mitochondrial abnormalities. The rat model of upper airway occlusion showed pulmonary and cardiac changes that have been described in OSAS.ConclusionsA rat model of upper airway occlusion resulted in physiological and morphological changes in the lung and heart due to hypoxia, and may be used for future studies on OSAS.

Life-Threatening paediatric odontogenic cellulitis secondary to a partially erupted primary molar

Abstract: A 15-month-old male was admitted to hospital with a facial swelling of unknown origin which was of rapid onset over three hours, resulting in airway occlusion and septic shock. Ultimately, the swelling was found to be of odontogenic origin and was managed with high dose intra-venous antibiotics. Cellulitis of the face can be life-threatening and it is important to be aware of the clinical signs and ensure that the patient receives appropriate care to prevent deterioration. CPD/Clinical Relevance: It is essential for dentists in primary and secondary care to recognize and understand how to manage or refer a patient with facial cellulitis, and also for medical teams to seek prompt dental input in cases of facial swelling with a possible dental cause.

Advanced pulmonary MRI to quantify alveolar and acinar duct abnormalities: Current status and future clinical applications.

There are serious clinical gaps in our understanding of chronic lung disease that require novel, sensitive, and noninvasive in vivo measurements of the lung parenchyma to measure disease pathogenesis and progressive changes over time as well as response to treatment. Until recently, our knowledge and appreciation of the tissue changes that accompany lung disease has depended on ex vivo biopsy and concomitant histological and stereological measurements. These measurements have revealed the underlying pathologies that drive lung disease and have provided important observations about airway occlusion, obliteration of the terminal bronchioles and airspace enlargement, or fibrosis and their roles in disease initiation and progression. ex vivo tissue stereology and histology are the established gold standards and, more recently, micro-computed tomography (CT) measurements of ex vivo tissue samples has also been employed to reveal new mechanistic findings about the progression of obstructive lung disease in patients. While these approaches have provided important understandings using ex vivo analysis of excised samples, recently developed hyperpolarized noble gas MRI methods provide an opportunity to noninvasively measure acinar duct and terminal airway dimensions and geometry in vivo, and, without radiation burden. Therefore, in this review we summarize emerging pulmonary MRI morphometry methods that provide noninvasive in vivo measurements of the lung in patients with bronchopulmonary dysplasia and chronic obstructive pulmonary disease, among others. We discuss new findings, future research directions, as well as clinical opportunities to address current gaps in patient care and for testing of new therapies. Level of Evidence: 5 Technical Efficacy: Stage 5 J. Magn. Reson. Imaging 2019;50:28-40.

Inspiratory pressure-generating capacity is preserved during ventilatory and non-ventilatory behaviours in young dystrophic mdx mice despite profound diaphragm muscle weakness.

Respiratory muscle weakness is a major feature of Duchenne muscular dystrophy (DMD), yet little is known about the neural control of the respiratory muscles in DMD and animal models of dystrophic disease. Substantial diaphragm muscle weakness is apparent in young (8-week-old) mdx mice, although ventilatory capacity in response to maximum chemostimulation in conscious mice is preserved. Peak volume- and flow-related measures during chemoactivation are equivalent in anaesthetized, vagotomized wild-type and mdx mice. Diaphragm and T3 external intercostal electromyogram activities are lower during protracted sustained airway occlusion in mdx compared to wild-type mice. Yet, peak inspiratory pressure generation is remarkably well preserved. Despite profound diaphragm weakness and lower muscle activation during maximum non-ventilatory efforts, inspiratory pressure-generating capacity is preserved in young adult mdx mice, revealing compensation in support of respiratory system performance that is adequate, at least early in dystrophic disease. Diaphragm dysfunction is recognized in the mdx mouse model of muscular dystrophy; however, there is a paucity of information concerning the neural control of dystrophic respiratory muscles. In young adult (8weeks of age) male wild-type and mdx mice, we assessed ventilatory capacity, neural activation of the diaphragm and external intercostal (EIC) muscles and inspiratory pressure-generating capacity during ventilatory and non-ventilatory behaviours. We hypothesized that respiratory muscle weakness is associated with impaired peak inspiratory pressure-generating capacity in mdx mice. Ventilatory responsiveness to hypercapnic hypoxia was determined in conscious mice by whole-body plethysmography. Diaphragm isometric and isotonic contractile properties were determined ex vivo. In anaesthetized mice, thoracic oesophageal pressure, and diaphragm and EIC electromyogram (EMG) activities were recorded during baseline conditions and sustained tracheal occlusion for 30-40s. Despite substantial diaphragm weakness, mdx mice retain the capacity to enhance ventilation during hypercapnic hypoxia. Peak volume- and flow-related measures were also maintained in anaesthetized, vagotomized mdx mice. Peak inspiratory pressure was remarkably well preserved during chemoactivated breathing, augmented breaths and maximal sustained efforts during airway obstruction in mdx mice. Diaphragm and EIC EMG activities were lower during airway obstruction in mdx compared to wild-type mice. We conclude that ventilatory capacity is preserved in young mdx mice. Despite profound respiratory muscle weakness and lower diaphragm and EIC EMG activities during high demand in mdx mice, peak inspiratory pressure is preserved, revealing adequate compensation in support of respiratory system performance, at least early in dystrophic disease. We suggest that a progressive loss of compensation during advancing disease, combined with diaphragm dysfunction, underpins the development of respiratory system morbidity in dystrophic diseases.

Sensory consequences of critical inspiratory constraints during exercise in pulmonary arterial hypertension

We aimed to assess detailed ventilatory and sensory responses to exercise contrasting subjects with and without PAH.20 non-smoking patients with PAH (37.5 ± 12.1 ys; FEV1/FVC = 0.77 ± 0.04; mPAP by heart catheterization = 50.6 ± 18.1 mmHg) and 10 matched controls performed cycling cardiopulmonary exercise test with serial assessments of dyspnea, airway occlusion pressure during the first 0.1 s (P0.1) of tidal volume and inspiratory capacity (IC).Patients showed lower spirometric variables compared to controls. Dyspnea and ventilation (VE) were significantly higher in patients for a given work rate. Dyspnea persisted more intense in patients even when expressed as a function of VE. Lower IC at rest (in non-hyperinflators; n = 10) or exercise-induced reduction in IC (in hyperinflators) predisposed patients to achieve earlier and at lower workloads a critical inspiratory reserve volume (IRV). At this point, there was a sudden rise in P0.1 and dyspnea perception.Attainment of a critical IRV at premature workloads leads to neuromechanical dissociation with an abrupt increment in exertional dyspnea.

Computer simulated assessment of radio frequency electromagnetic waves for the detection of obstructive sleep apnea

Abstract Obstructive sleep apnea/hypopnea syndrome (OSAHS) is the most common form of sleep-disorder breathing (SDB). Recurring restriction or occlusion of the upper airway throughout the night concurrent with continued respiratory efforts lasting more than 10 s characterizes the disorder. Prevalence of OSAHS is increasing globally, with a high association with obesity, hypertension, and heart failure. Nocturnal polysomnography (NPSG), which is the gold standard for OSAHS diagnosis, is scarce, expensive, and cumbersome. Methods for home screening and diagnosis of the disorder, directly and indirectly, are highly sought after to amend or replace NPSG. Well-established norms and procedures for electromagnetic (EM) antenna design, radiation pattern and characterization, and signal reception and measurements can be employed for the direct detection of upper airway occlusion. The utilization of radio-frequency (RF) EM antennas is desirable, as it is inexpensive, and simple to design and implement. In this paper, a computerized simulation of a new EM sensing system for direct detection of the occlusion in the upper airway is presented. Electromagnetic, anatomical, and RF safety constraints are taken into consideration. The theoretical basis of EM, antenna design, and physiological interactions with EM waves are presented. The proposed methodology for creating an anatomically-correct neck and airway simulated phantoms to test the hypothesis and the results of the tests are presented. Hypothesis Radio-frequency electromagnetic waves transmitted through an open airway will have different energy levels at the distal side of the neck compared to those associated with a fully occluded airway. Methodology A system is designed comprising a simulated phantom model of the upper airway and neck with the approximate anatomical dimensions and dielectric properties of homogenous neck tissue. Additionally, an RF patch antenna is designed and matched to the phantom neck. An iterative process is developed and implemented for the patch antenna design and coupling with a tissue. Simulation of the EM wave propagation and dissipation throughout the neck in the open and closed airway cases is provided and calculated based on the specific absorption ratios (SAR). The results of several permutations of antenna orientation with respect to the neck and several gaps between the antenna and the neck are provided. Results the Computer simulations for all antenna orientation and location have shown that the EM energy levels recorded from open airway phantom models are statistically different and lower than those recorded from the occluded airway phantom models. Conclusions The results of this study support the hypothesis that it is theoretically feasible to use electromagnetic energy to distinguish between open and occluded upper airway.

Fatalna aspiracija kukuruznog zrna - prikaz slučaja

Introduction: Asphyxiation by aspirationinhalation of foreign bodies is a form of violent mechanical asphyxia and can occur at any age, most commonly in children and the elderly. In children up to third age choking is a significant cause of morbidity and mortality. Mortality due to aspiration of foreign bodies is higher in children because of the relatively narrow airways and less developed protective mechanisms. The size, type, shape and place of obstruction with foreign body leads to the diversity of clinical picture. Case report. We present the case of a 15 month-old girl, who was found by her mother in her house in a village, lying down, cyanotic, collapsed, without breathing. Autopsy showed that the cause of death was acute respiratory obstruction with impacted grains of corn in two places, on the larynx entrance and in the right bronchus. Conclusion. The diagnosis of death by asphyxiation due to aspiration of foreign bodies is set at autopsy, when the place of airway occlusion is found. If a foreign body was removed during providing assistance, the diagnosis would be made based on medical records or history data of persons who were provided assistance. In cases of sudden deaths of young children, in order to clarify pathophysiological mechanism and mode of death in each case, a pathologist should always keep in mind the possibility of aspiration of foreign bodies, and in accordance with this, carefully apply appropriate autopsy techniques to locate the place of obstruction, with special regard to local finding in airways.

Reflex response to airway occlusion in human inspiratory muscles when recruited for breathing and posture.

Briefly occluding the airway during inspiration produces a short-latency reflex inhibition in human inspiratory muscles. This occlusion reflex seems specific to respiratory muscles; however, it is not known whether the reflex inhibition has a uniform effect across a motoneuron pool when a muscle is recruited concurrently for breathing and posture. In this study, participants were seated and breathed through a mouthpiece that occluded inspiratory airflow for 250 ms at a volume threshold of 0.2 liters. The reflex response was measured in the scalene and sternocleidomastoid muscles during 1) a control condition with the head supported in space and the muscles recruited for breathing only, 2) a postural condition with the head unsupported and the neck flexors recruited for both breathing and to maintain head posture, and 3) a large-breath condition with the head supported and the volume threshold raised to between 0.8 and 1.0 liters to increase inspiratory muscle activity. When normalized to its preocclusion mean, the reflex response in the scalene muscles was not significantly different between the large-breath and control conditions, whereas concomitant recruitment of these muscles for posture control reduced the reflex response by half compared with the control condition. A reflex response occurred in sternocleidomastoid when it contracted phasically as an accessory muscle for inspiration during the large-breath condition. These results indicate that the occlusion reflex does not produce a uniform effect across the motoneuron pool and that afferent inputs for this reflex most likely act via intersegmental networks of premotoneurons rather than at a motoneuronal level. NEW & NOTEWORTHY In this study, we investigated the effect of nonrespiratory activity on the reflex response to brief sudden airway occlusions in human inspiratory muscles. We show that the reflex inhibition in the scalene muscles was not uniform across the motoneuron pool when the muscle was recruited concurrently for breathing and postural control. The reflex had a larger effect on respiratory-driven motoneurons than those recruited to maintain head posture.

Maxillomandibular Rotational Advancement: Airway, Aesthetics, and Angle's Considerations.

Obstructive sleep apnea is a medical syndrome with multifactorial pathophysiology. Surgery can be the primary treatment option when anatomic factors are identified with narrowing at specific or general levels of pharyngeal airway. The surgeries are directed to the etiologic anatomic structure to achieve greatest effectiveness. Body weight, Mallampati scale, and tonsil grade are key evaluations to select effective surgical procedures. Surgical weight reduction, maxillomandibular advancement, and pharyngeal soft tissue surgeries are considered for the patient with obesity, maxillomandibular retrognathism, and tonsillar hypertrophy, respectively. Tailored surgical planning can meet the patients needs for airway, esthetics, and normal Angle's occlusion.

Efficacy and safety of cryotherapy combined with balloon dilatation through electronic bronchoscope in the management of airway occlusion caused by scar stenosis type of tracheobronchial tuberculosis

Objective: To investigate the efficacy and safety of cryotherapy combined with balloon dilatation through electronic bronchoscope in the management of airway occlusion caused by scar stenosis type of tracheobronchial tuberculosis (TBTB). Methods: From December 2008 to May 2016, 98 cases of airway occlusion caused by scar stenosis of TBTB were diagnosed by microbiology, histopathology, CT (computer tomography), bronchial reconstructions and bronchoscopy. All patients underwent routine anti-tuberculosis chemotherapy and cryotherapy through bronchoscope. The patients whose airways were reopened successfully received balloon dilatation through bronchoscope subsequently. The treatment effects were estimated by indexes including clinical efficacy, modified medical research council (mMRC) dyspnea scale and complications. Results: Among the 98 patients, airway occlusion in 87 cases were reopened successfully by cryotherapy for (10±4) times, and then these patients received balloon dilatation through bronchoscope for (7±3) times subsequently. The total effective rates were 76.53% and 72.45% after 3 and 12 months after the treatments respectively. Analysis of the disease courses of patients with different therapeutic efficacy showed that the median disease course was 3 months in healed cases, 5 months in effective cases and 9 months in ineffective cases. There was a significant difference between the ineffective and the total effective cases in disease courses (t=-15.012, P<0.01). The average of mMRC score changed from (3.8±0.5) before the procedure, to (1.1±0.7), (1.2±0.7) and (1.2±0.7) immediately, 3 and 12 months after the treatments. The difference was significant between the scores before and after therapy (t=30.398-31.058, P<0.01), but not among the 3 scores after treatments. No serious complications were observed in all cases. Conclusions: Cryotherapy combined with balloon dilatation through electronic bronchoscope was a very safe and effective method in the management of airway occlusion caused by scar stenosis of tracheobronchial tuberculosis. A shorter course of disease indicated more benefits for patients.

Lethal manifestations of angioedema

An 86-year-old woman with a history of angioedema was found dead at her home address. She had recently complained of a swollen tongue. At autopsy the tongue was grossly edematous, protruding from the mouth. There was also marked edema of the tonsillar fossae, epiglottis and glottic inlet, causing critical obstruction. Histology of the tongue and upper airway demonstrated marked submucosal edema. Death was attributed to upper airway obstruction due to angioedema of the tongue, oropharynx and glottic inlet. Angioedema is characterized by localized non-pitting edema of the deep dermis and subcutaneous/submucosal tissues. It may be acute or chronic, acquired or inherited. Sudden death may result from critical airway occlusion, although both stroke and ischemic heart disease are known to occur. Post mortem genetic testing for hereditary variants can be conducted for SERPING1 gene and F12 gene/THR328 mutations.

DIFFICULT BRONCHOSCOPIC EXTRACTION OF MULTIPLE ASPIRATED TEETH AS A RESULT OF HEAD INJURY AFTER ACUTE MYOCARDIAL INFARCTION LEADING TO MOTOR VEHICLE ACCIDENT

SESSION TITLE: Allergy and Airway SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/09/2018 01:15 PM - 02:15 PM INTRODUCTION: Tracheobronchial foreign body aspiration(FBA) in adults is common requiring early recognition to prevent potential complications. Presentation may be subtle, particularly if there are other confounding clinical factors, and requires a high index of suspicion(1). Atelectasis, air trapping, pulmonary infiltrates, and mediastinal shift may be the initial signs of FBA. A common setting is loss of consciousness with trauma, intoxication or neuological disease(1). Delay in diagnosis can be life-threatening, with occlusion of the large airways, potential asphyxiation, pneumonia and abscess,and delayed sepsis(2). Over 90% of foreign bodies are radiolucent and teeth are fortunately radiodense. The right bronchus is the most common site of FBA vs. the distal airways, and are rarely bilateral as in this case. This case report reveal tricks via FB for retrieval of multiple, distally impacted teeth. CASE PRESENTATION: We report a case of FBA in a 64-year-old man who lost consciousness after an acute myocardial infarction, who hit his head on the steering wheel developed a a subarachnoid haemorrhage in a motor vehicle accident(MVA). He was hemodynamic stable with GCS 8/15. It was noted he had lost several teeth. CXR demonstrated bilateral lower lobe hyperlucencies(Figure 1A). CT chest confirmed one tooth in the right lower(Figure 1B) and two in the left lower lobe(Figure 1C, D).FB was performed through the ETT, retrieving three aspirated teeth(Figure 2A). The small, smooth hard nature of the teeth thwarted initial attempts for retrieval with alligator forceps. Multiple adjunctive techniques were employed, including enclosing the teeth with various retrieval devices using a Roth net(Figure 2B,C) and Dormia basket(Figure 2D)(1). The patient was subsequently extubated. DISCUSSION: Rigid bronchoscopy might be considered the preferred modality for foreign body removal, in the face of bleeding, with centrally-located foreign bodies, or massive haemoptysis. In this case, foreign bodies were distal, there was no active bleeding, and there was no other reason to proceed to the operating room, the necessity of C-spine precautions, making rigid bronchoscopy not optimal. Thus flexible bronchoscopy was deemed most suitable and could be performed at the bedside.Advancements in FB techniques have made it the initial preferred method for diagnosis and removal of foreign bodies in adults (1). FB also has advantages in its ease, less sedation requirement, less discomfort, ability to access more peripheral foreign bodies as well as being more feasible in patients with contraindications to rigid bronchoscopy(1). CONCLUSIONS: A multidisciplinary approach between cardiothoracic surgery and pulmonary medicine is recommended for successful complex removal of foreign bodies(6) with multiple adjuncts available in this highly critically ill patient. Reference #1: (1) Rafanan AL, Mehta AC. Adult airway foreign body removal: What's new? Clin Chest Med 2001;22(2):319-330. Reference #2: (2) Debeljak A, Kecelj P. Bronchoscopic removal of foreign bodies in adults: experience with 62 patients from 1974–1998. European Respiratory Journal 2008;14(4):792-795. Reference #3: (3) Weber SM, Chesnutt MS, Barton R, Cohen JI. Extraction of dental crowns from the airway: a multidisciplinary approach. Laryngoscope 2005 Apr;115(4):687-689. DISCLOSURES: no disclosure on file for Lawrence Chin; No relevant relationships by Christine Feliu, source=Web Response no disclosure on file for Amour Patel; No relevant relationships by Barbara Robinson, source=Web Response

Diaphragm muscle function following midcervical contusion injury in rats

Midcervical spinal cord contusion injury results in tissue damage, disruption of spinal pathways, and motor neuron loss. Unilateral C4 contusion results in loss of 40%-50% of phrenic motor neurons ipsilateral to the injury (~25% of the total phrenic motor neuron pool). Over time after unilateral C4 contusion injury, diaphragm muscle (DIAm) electromyogram activity increases both contralateral and ipsilateral to the side of injury in rats, suggesting compensation because of increased activation of the surviving motor neurons. However, the impact of contusion injury on DIAm force generation is less clear. Transdiaphragmatic pressure (Pdi) was measured across motor behaviors over time after unilateral C4 contusion injury in adult male Sprague-Dawley rats. Maximum Pdi (Pdimax) was elicited by bilateral phrenic nerve stimulation at 7 days postinjury. We hypothesized that Pdimax is reduced following unilateral C4 contusion injury, whereas ventilatory behaviors of the DIAm are unimpaired. In support of our hypothesis, Pdimax was reduced by ~25% after unilateral C4 contusion, consistent with the extent of phrenic motor neuron loss following contusion injury. One day after contusion injury, the Pdi amplitude during airway occlusion was reduced from ~30 to ~20 cmH2O, but this reduction was completely reversed by 7 days postinjury. Ventilatory behaviors (~10 cmH2O), DIAm-specific force, and muscle fiber cross-sectional area did not differ between the laminectomy and contusion groups. These results indicate that the large reserve capacity for DIAm force generation allows for higher-force motor behaviors to be accomplished despite motor neuron loss, likely reflecting changes in motor unit recruitment. NEW & NOTEWORTHY Respiratory muscles such as the diaphragm generate the pressures necessary to accomplish a variety of motor behaviors ranging from ventilation to near-maximal expulsive behaviors. However, the impact of contusion injury on diaphragm pressure generation across behaviors is not clear. The present study shows that contusion injury impairs maximal pressure generation while preserving the ability of the diaphragm to accomplish lower-force motor behaviors, likely reflecting changes in diaphragm motor unit recruitment.

A Resuscitation Option for Upper Airway Occlusion Based on Bolus Transtracheal Lung Inflation.

BackgroundAcute laryngospasm sufficient to cause obstructive apnea is a medical emergency that can be difficult to manage within the very short time available for establishing an airway. We have presented substantial evidence that laryngospasm‐based obstructive apnea is the cause of sudden death in epilepsy, and airway management is particularly challenging during seizure activity.ObjectiveWe sought to determine if the transtracheal delivery of a bolus of oxygen or room air below the level of an obstruction to inflate the lungs could be an effective method to prolong the time available for responders seeking to establish a stable airway, and, if so, what could be learned about optimization of delivery parameters from a rat model.MethodsRats were fitted with a t‐shaped tracheal tube for controlling access to air and for measuring airway pressures. After respiratory arrest from simulated laryngospasm, bolus transtracheal lung inflation with a volume of gas equivalent to half the vital capacity was delivered to the closed respiratory system as the only resuscitation step.ResultsBolus lung inflation was sufficient for resuscitation, improving cardiac function and re‐establishing adequate oxygen status to support life. Inflation steps could be repeated and survival times were approximately 3 times that of non‐inflated lungs.ConclusionThe properties and consequences of bolus lung inflation are described as a foundation for procedures or devices that can be useful in cases of severe laryngospasm and other cases of upper airway obstruction.Level of Evidence3