Airway Blockage Research Articles

Correcting a Bent Septum by a K-Wire Stabilization During an Extracorporeal Septal Reconstruction

Extracorporeal septoplasty has been successfully employed in difficult cases of septal deviation. A novel technique of wire fixation during extracorporeal septoplasty is presented. All patients had complete or near complete nasal airway blockage. The quadrangular cartilage was entirely removed through an open approach. The bent areas were scored, and K-wires were placed to fix the cartilage in the straightened position. The cartilage was replaced and fixated to the bony septum, upper lateral cartilages, and anterior maxillary crest. The K-wire was removed after 6weeks. Fifteen of 17 patients retained straightness of the septum, and 13 of 17 achieved subjective improvement in nasal breathing. There was one skin infection which was treated with oral antibiotics with complete resolution. Two wires required a percutaneous incision to remove. The presented technique of extracorporeal septoplasty with wire fixation can be successfully employed for extreme septal deviations. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Relation Between the Craniocervical Cephalometric Analysis and Class I, II and III Skeletic Patterns in Young Subjects

The skull posture on the spine is an important factor for the diagnosis of craniomandibulars functional disorders in children, as well as in adults. Alterations in biomechanics may be evidenced in common x-rays. The aim of this study was to relate findings of craniocervical analysis with skeletal pattern Class I, II, III in individuals from 7 to 12 years old. X-rays of 92 individuals were taken by NHP method and digitalized for computerized analysis of skeletic patterns and craniocervical analysis. Descriptive analysis was used to relate craniocervical analysis values with the type of skeletal pattern presented by individuals. For skeletal pattern Class I, II and III, nasopharyngeal soft tissue percentage and oropharyngeal soft tissue linear quantity were above normality value; nasopharyngeal cervical plot was normal and hyoid triangle was positive for the majority of the individuals. The angular relationship between skull and cervical spine show values lower than those considered normal for skeletal pattern class I and II. It was concluded that in the majority of the individuals with skeletal pattern Class I, II and III had high values of airway blockage, head posterior rotation, nasopharyngeal cervical plot with normal values and positive hyoid triangle.

Konditionierung der Atemluft in der Nase

We present a review of nasal-air conditioning, a process essential to undisturbed gas exchange and cleansing of the respiratory mucosa in the nose. A selective literature review was made on the basis of in vivo measurements and computer simulation of the upper airways as well as the authors' own clinical and experimental data. Healthy subjects normally breathe through the nose, although the nasal airways have significantly higher airway resistance compared to the oral cavity, which is opened for breathing during exercise, in the case of nasal airway blockage, or in allergic rhinitis. In addition to olfaction, the main tasks of nasal breathing include: cleansing, defense, and conditioning (i.e., humidification and heating). The current knowledge of nasal conditioning processes will be discussed. In addition, research activities of particular relevance for diagnosis and intervention in various pathologies of the upper airways will be presented.

Simulation of sprayed particle deposition in a human nasal cavity including a nasal spray device

Effective nasal drug delivery is highly dependent on the delivery of drug from the nasal spray device. Atomisation of liquid spray occurs through the internal atomizer that can produce many forms of spray patterns and two of these, hollow-cone and full-cone sprays, are evaluated in this study to determine which spray pattern produced greater deposition in the middle regions of the nasal cavity. Past studies of spray particle deposition have ignored the device within the nasal cavity. Using computational fluid dynamics (CFD), two computational models of human nasal cavity model were reconstructed from CT-scans, where the difference between the two models was the presence of the nasal spray device accounting for the airway blockage at one of the nostrils. Experimental measurements from Particle Droplet Image Analyser (PDIA) were taken in order to gain confidence in determining the initial particle conditions for the computational models. An airflow field is induced through a negative pressure flow condition applied at the pharynx instead of constant flow rates at the left and the right nasal cavities. Subsequent airflow patterns and its effects on particle deposition, with and without a spray device, are compared. Contours and streamlines of the flow field revealed that the presence of a spray device in the nasal vestibule produced higher levels of disturbed flow, which helped the dispersion of the sprayed particles. Particle deposition was found to be high in the anterior regions of the nasal cavity caused by its inertia. Evaluation of the two spray types found that hollow spray cones produced more deposition in the middle regions of the nasal cavity. This paper also demonstrates the CFD methodology used, which can help in better understanding the design of future atomizers for nasal spray use.

Heated Humidification Versus Heat and Moisture Exchangers for Ventilated Adults and Children

Humidification by artificial means must be provided when the upper airway is bypassed during mechanical ventilation. Heated humidification (HH) and heat and moisture exchangers (HMEs) are the most commonly used types of artificial humidification in this situation. To determine whether HHs or HMES are more effective in preventing mortality and other complications in people who are mechanically ventilated. We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library 2010, Issue 4) and MEDLINE, EMBASE and CINAHL (January, 2010) to identify relevant randomized controlled trials. We included randomized controlled trials comparing HMEs to HHs in mechanically ventilated adults and children. We included randomized crossover studies. We assessed the quality of each study and extracted the relevant data. Where appropriate, results from relevant studies were meta-analyzed for individual outcomes. We included 33 trials with 2833 participants; 25 studies were parallel group design (n = 2710) and 8 crossover design (n = 123). Only 3 included studies reported data for infants or children. There was no overall effect on artificial airway occlusion, mortality, pneumonia, or respiratory complications; however, the PaCO(2) and minute ventilation were increased when HMEs were compared to HHs and body temperature was lower. The cost of HMEs was lower in all studies that reported this outcome. There was some evidence that hydrophobic HMEs may reduce the risk of pneumonia and that blockages of artificial airways may be increased with the use of HMEs in certain subgroups of patients. There is little evidence of an overall difference between HMEs and HHs. However, hydrophobic HMEs may reduce the risk of pneumonia and the use of an HMEs may increase artificial airway occlusion in certain subgroups of patients. Therefore, HMEs may not be suitable for patients with limited respiratory reserve or prone to airway blockage. Further research is needed relating to hydrophobic versus hygroscopic HMEs and the use of HMEs in the pediatric and neonatal populations. As the design of HMEs evolves, evaluation of new generation HMEs will also need to be undertaken.

Preliminary Development and Engineering Evaluation of a Novel Cricothyrotomy Device.

Cricothyrotomy is one of the procedures used to ventilate patients with upper airway blockage. This paper examines the most regularly used and preferred cricothyrotomy devices on the market, suggests critical design specifications for improving cricothyrotomy devices, introduces a new cricothyrotomy device, and performs an engineering evaluation of the device’s critical components. Through a review of literature, manufacturer products, and patents, four principal cricothyrotomy devices currently in clinical use were identified. From the review, the Cook™ Melker device is the preferred method of clinicians but the device has acknowledged problems. A new emergency needle cricothyrotomy device (ENCD) was developed to address all design specifications identified in literature. Engineering, theoretical, and experimental assessments were performed. In situ evaluations of a prototype of the new device using porcine specimens to assess insertion, extraction, and cyclic force capabilities were performed. The device was very successful in its evaluation. Further discussion focuses on these aspects and a comparison of the new device with established devices. The proposed emergency needle cricothyrotomy device performed very well. Further work will be pursued in the future with in-vitro and in-vivo with canine models demonstrates the capabilities of the ENCD.

Roles of ROS/TACE in neutrophil elastase-induced mucus hypersecretion in NCI-H292 airway epithelial cells.

Complications arise in chronic obstructive pulmonary diseases (COPD) with excessive mucus production, especially during the exacerbation period, which contributes to airway blockage and bacterial infection. Neutrophil elastase (NE) is detected at high levels in airway secretions, and is the primary inducer of mucin production. Understanding the mechanism of NE-induced overproduction of mucin may lead to new therapies for COPD. It is known that activation of epidermal growth factor receptor (EGFR) and its downstream signaling cascade are involved in mucin production. However, the mechanism of NE-induced EGFR activation remains unclear. Tumor necrosis factor-α-converting enzyme (TACE) cleaves pro-transforming growth factor (TGF)-α in airway epithelial cells to release the mature, soluble TGF-α form, which subsequently binds to and activates EGFR. In this investigation, we demonstrate that NE-induced mucin production requires reactive oxygen species (ROS) production, which activates TACE, resulting in TGF-α shedding, and EGFR phosphorylation in NCI-H292 epithelial cells.

Preliminary Development and Engineering Evaluation of a Novel Cricothyrotomy Device

Cricothyrotomy is one of the procedures used to ventilate upper airway blockage patients. The objectives of this paper are to examine the most regularly used cricothyrotomy devices, to suggest critical design specifications for improving the devices, and to introduce a new cricothyrotomy device as well as perform an engineering evaluation of the devices’ critical components. A review of the literature, manufacturer products and patents was performed to determine current cricothyrotomy devices in use. Four principal cricothyrotomy devices are currently in clinical use. From our review the Cookâ„¢ Melker device is the preferred method of clinicians but has acknowledged problems. Our group has developed a novel cricothyrotomy device, which addresses all design specifications and was shown to be very promising through engineering and in situ evaluations.

Assessment of oropharynx using cone beam computed tomography—Change in volume during oropharynx growth—

Recently airway blockage accidents have increased in Japan, and airway blockage accidents involving children account for 12% of the total. However, the causes of airway blockage accidents are not clear. The oropharynx plays an important role in feeding and swallowing by helping to prevent aspiration and airway blockage accidents. Few studies, however, detail the changes in volume of the oropharynx during growth. The relationship, therefore, between the volume of the oropharynx and growth was investigated in this study. The subjects, 50 males and 50 females aged 7 to 15 years, were grouped according to a dental development age index (Hellman Dental Age), resulting in a dental development range from IIC to IVA. Cone beam computed tomography (CB Mercuray, Hitachi) was used to scan each subject's head, and a three-dimensional modeling system was used to measure the oropharynx volume, height and other. The mean and standard deviation of the height of males was 35.48 ± 6.85 mm and of females, 34.78 ± 7.42 mm. In male and female subjects, the height of the oropharynx airway increased from IIC to IVA. The mean and standard deviation of the oropharynx volume of males was 5,570.79 ± 3,790.30 mm 3 and of females, 4,942.80 ± 2,818.75 mm 3 . In male and female subjects, the volume of the oropharynx airway increased significantly from IIIC to IVA. Therefore, this study suggests that there is a strong relationship between the increase of the oropharynx airway and the time and condition of eruption of the second molar teeth from period of IIC to IVA of the Hellman Dental Age index.

Motions of a cantilevered flexible plate in viscous channel flow driven by a constant pressure drop

AbstractAn improved approach for studying the stability of a cantilevered flexible plate positioned within two‐dimensional viscous channel flow is presented in the context of human upper‐airway dynamics. Previous work has used constant inlet velocity conditions. Here we model a constant pressure drop that may better reflect inspiratory effort. Positioning of the flexible plate within the channel can also be varied. The constant pressure drop is imposed for each time step by computing appropriate inlet velocities. The Navier–Stokes equations are solved using an explicit finite‐element method written specifically for the channel geometry within which the fully coupled plate moves. The motion of the plate, driven by the pressure‐field, is modelled using classical thin‐plate mechanics with the addition of the fluid shear‐stress‐induced tension term. The investigation focuses on low‐amplitude motions of the flexible plate (soft‐palate) that, when unstable, may be the precursors to snoring and airway blockage during sleep. We show that imposing constant inlet velocity conditions generates over‐predictions of energy transfer between flow and flexible plate during inhalation. Finally, we show that offsetting the flexible plate within the channel leads to a reduction in oscillation frequency and a significant change to its energy interaction with the fluid flow. Copyright © 2009 John Wiley & Sons, Ltd.

Simulation of the effect of local obstructions and blockage on airflow and aerosol deposition in central human airways

Investigation of the effect of sidewall and carinal tumours, airway constrictions and airway blockage on the inspiratory airflow and particle deposition in the large central human airways was the primary objective of this study. A computational fluid and particle dynamics model was implemented, validated and applied in order to simulate the air and particle transport and to quantify the aerosol deposition in double airway bifurcation models. Our investigations revealed that surface abnormalities and tubular constrictions can significantly alter the airstreams and the related local aerosol deposition distributions. Sidewall tumours have lead to an enhanced deposition of large particles and caused lower deposition efficiency values of nano-particles compared to the deposition efficiency in healthy airways. Central tumours multiplied the deposition efficiency of large particles but hardly affected the deposition efficiency of nano-particles. Airway blockage caused a significant redistribution of particle deposition sites. The deposition efficiency of the inhaled aerosols in constricted airways was much higher than the same deposition efficiency in healthy airways. Current results might help in the understanding of the adverse health effects of the inhaled air-pollutants in patients with lung disease and might be integrated into future aerosol therapy protocols.

Rhinoplastic techniques for the nasal valve for the patient with sleep apnea

Treatment of nasal blockage is necessary to facilitate therapy of obstructive sleep apnea and improve continuous positive airway pressure tolerance. The importance of the nasal valve in controlling inspiratory airflow has been well documented. Defining the nasal valve region and correlating physiology with its anatomic and surgical findings can be confusing. Reliable interpretation of the different types of nasal valve dysfunction can be correlated with effective surgical repair to reduce nasal airway resistance. A simplified approach to standardizing surgical treatment of nasal valve problems is presented.

Instability of a cantilevered flexible plate in viscous channel flow

The stability of a flexible cantilevered plate in viscous channel flow is studied as a representation of the dynamics of the human upper airway. The focus is on instability mechanisms of the soft palate (flexible plate) that cause airway blockage during sleep. We solve the Navier–Stokes equations for flow with Reynolds numbers up to 1500 fully coupled with the dynamics of the plate motion solved using finite-differences. The study is 2-D and based upon linearized plate mechanics. When both upper and lower airways are open, the plate is found to lose its stability through a flutter mechanism and a critical Reynolds number exists. When one airway is closed, the plate principally loses its stability through a divergence mechanism and a critical flow speed exists. However, below the divergence-onset flow speed, flutter can exist for low levels of structural damping in the flexible plate. Our results serve to extend understanding of flow-induced instability of cantilevered flexible plates and will ultimately improve the diagnosis and treatment of upper-airway disorders.

Histamine receptors that influence blockage of the normal human nasal airway

1. The aim of this study was to investigate the mechanisms by which histamine causes nasal blockage. Histamine, 40-800 microg, intranasally into each nostril, induced significant blockage of the nasal airway in normal human subjects, as measured by acoustic rhinometry. 2. Oral pretreatment with cetirizine, 5-30 mg, the H1 antagonist, failed to reverse completely the nasal blockage induced by histamine, 400 microg. 3. Dimaprit, 50-200 microg, the H2 agonist, intranasally, caused nasal blockage, which was reversed by oral pretreatment with ranitidine, 75 mg, the H2 antagonist. 4. A combination of cetirizine, 20 mg, and ranitidine, 75 mg, caused greater inhibition of the nasal blockage caused by histamine, 400 microg, than cetirizine alone. In the presence of both antagonists, there was residual histamine-induced nasal blockage. 5. R-alpha-methylhistamine (R-alpha-MeH), 100-600 microg, the H3 agonist, intranasally, caused nasal blockage, which was not inhibited by either cetirizine or ranitidine. 6. Thioperamide, 700 microg, the H3 antagonist, intranasally, reversed the R-alpha-MeH-induced nasal blockage. Thioperamide alone had no significant action on the nasal blockage induced by histamine, 400 and 1000 microg, but, in the presence of cetirizine, 20 mg, thioperamide further reduced the histamine-induced nasal blockage. 7. Corynanthine, 2 mg, the alpha1-adrenoceptor antagonist, administered intranasally, caused nasal blockage. 8. Corynanthine produced a greater increase in nasal blockage when in combination with bradykinin compared to its combination with R-alpha-MeH. 9. There appears to be a contribution of H1, H2 and H3 receptors to histamine-induced nasal blockage in normal human subjects. The sympathetic nervous system actively maintains nasal patency and we suggest that activation of nasal H3 receptors may downregulate sympathetic activity.

Heritability of symptom domains in otitis media: a longitudinal study of 1,373 twin pairs.

Research on risk factors and pathogenesis of otitis media has emphasized the environment, but previous twin studies suggest a strong genetic component. In those studies, no attempt was made to differentiate the role of initial acute infection from the chronic airway blockage that frequently accompanies persistent effusion. The authors estimated genetic and environmental determination of both of these aspects of otitis media histories at three time points. A large and representative subset of a total population cohort of all twins born in England and Wales in 1994, was studied prospectively at ages 2, 3, and 4 years (monozygotic, n = 715; dizygotic, n = 658). For the total symptom score, the estimated heritabilities at ages 2, 3, and 4 years were 0.49, 0.66, and 0.71, respectively. All correlations for the total score found in monozygotic twins were about 0.9, but correlations were lower for dizygotic twins (p < 0.65). Shared environmental influences declined in importance over time (0.41, 0.22, and 0.16 at ages 2, 3, and 4 years, respectively). No gender differences were found in parameter estimates. Symptoms of acute infections showed lower heritability (0.57 on average) and higher shared environment (0.18) than did chronic airway blockage (0.72 heritability and 0.10 shared environment). The strong genetic component, which this study confirms, is not unitary but distributes differently across the phenotypic aspects of otitis media and probably across pathogenetic stage.

Epiglotitis aguda en adultos. Nuestra casuística en 11 años

We report a retrospective study of 20 cases of acute epiglottitis in adults admited at our hospital between 1991 and 2001. We gather a series of variables: Patient sex, age, year and month of admission, personal history, initial clinical symptoms, complementary tests asked, given treatment, evolution and hospital average stay. We found an obvious predominance in male (19:1 with respect to female), with an average age of 45 years. The main symtomps were dysphagia-odynophagia (85%), followed by fever (55%) and pharyngocervical pain. Dyspnea was confirmed in 9 of 20 patients (45%); 5 of them required airway control with the help of intubation in one case, urgent coniotomy in three cases and tracheotomy in another one. A patient suffered from an acute mediastinitis and required assistance and medical IV extended treatment in UCI. We show a case of another patient who suffered sudden cardiorespiratory arrest a followed by death. He did not present previus dyspnea. Acute epiglottitis in adults is a rare pathology with a good prognosis in general, but may lead to an unpredictable and serious complication even in the absence of airway blockage. We carry out a medical literature review in this respect.

Surgery in the treatment of snoring and sleep apnea

Simple snoring and obstructive sleep apnea are part of a complex disease process with a high prevalence. Surgical treatment options have been developed by otolaryngologists over the last decades. Knowledge of different surgical procedures is required to address the various findings during preoperative assessment. Patients with nasal airway blockage due to septal deviation, large turbinates or polyps may benefit from endonasal surgery. Obstructive tonsils, palatal webbing, and an enlarged uvula require surgical approaches including the soft palate and tonsils. The controversy on indications and contraindications for the standard uvulopalatopharyngoplasty, laser-assisted uvulopalatoplasty and the use of radiofrequency is still ongoing. Dysgnathia may require maxillofacial surgery and macroglossia may be treated with reductive surgery of the tongue. Narrowing of the posterior airway space at the level of the tongue base may be addressed by advancement of the bony insertion of the genioglossus muscle and suspension of the hyoid. A new procedure is the suspension of the tongue with a non-resorbable suture fixed to a mandible anchored screw. Our first promising results need to be re-evaluated over time.

HAEMORRHAGE INTO THE TRACHEA AND BRONCHI FOLLOWING INDUCTION OF ANAESTHESIA: A Case Report

SUMMARY A case is described of haemorrhage into the trachea and bronchi, following induction of anaesthesia, of sufficient severity to cause complete airway blockage. Removal of blood and blood clots by a suction catheter immediately cleared the airway and allowed the lungs to be re-inflated with oxygen. The patient gave a long history of bronchiectasis. It is suggested that the haemorrhage may either have been the result of a spontaneous haemoptysis or have resulted from trauma to a hyperaemic tracheal mucosa.