Airway Opening Research Articles

Operative team checklist for aerosol generating procedures to minimise exposure of healthcare workers to SARS-CoV-2

ObjectivesIn many countries around the world, the COVID-19 pandemic has resulted in health services being diverted to manage patients with the condition. There are situations however that still require the undertaking of aerosol generating procedures (AGP) with potentially high exposure of healthcare workers to SARS-CoV-2 transmission through droplet, contact and possibly airborne routes. The objective of this paper is to explore a structured way for the operative team to approach AGP to reduce aerosolisation of secretions, decrease open airway time and minimise staff exposure. MethodsThe authors (otolaryngologists, anaesthetists and nursing staff) created a unified operative team checklist based on collation of national and international specialty society statements, local state government recommendations, hospital policies and literature review. Simulation was undertaken and the checklist was refined after performing AGP on patients with unknown (presumed positive) COVID-19 status. ResultsAn 8 step operative team checklist is provided describing details for the immediate pre-operative, intra-operative and post-operative journey of the patient to encourage healthcare workers to reflect upon and modify usual practice during AGP to mitigate exposure to SARS-CoV-2. The example of paediatric laryngo-bronchoscopy for diagnostic purposes or retrieval of an inhaled airway foreign body is used to illustrate the steps however the checklist structure is modifiable for other AGP and adaptable for local needs. ConclusionsAt a time of overwhelming and changing information and recommendations, an operative team checklist may provide some structure to healthcare workers undertaking AGP to reduce anxiety, maintain focus, prompt consideration of alternatives and potentially reduce risk.

Tracheostomy Management during the COVID-19 Pandemic.

The ongoing coronavirus disease 2019 pandemic has led to unprecedented demands on the modern health care system, and the highly contagious nature of the virus has led to particular concerns of infection among health care workers and transmission within health care facilities. While strong data regarding the transmissibility of the infection are not yet widely available, preliminary information suggests risk of transmission among asymptomatic individuals, including those within health care facilities. We believe that the presence of a tracheostomy or laryngectomy stoma poses a unique risk of droplet and aerosol spread particularly among patients with unsuspected infection. At our institution, guidelines for the care of open airways were developed by a multidisciplinary open airway working group, and here we review those recommendations to provide practical guidance to other institutions.

Otolaryngology during COVID-19: Preventive care and precautionary measures.

Since the outbreak of novel coronavirus disease (COVID-19) in December 2019, it has spread to various regions and countries, forming a global pandemic. Reducing nosocomial infection is a new issue and challenge for all healthcare systems. Otolaryngology is a high-risk specialty as it close contact with upper respiratory tract mucous, secretions, droplets and aerosols during procedures and surgery. Therefore, infection prevention and control measures for this specialty are essential. Literatures on the epidemiology, clinical characteristics and infection control measures of COVID-19 were reviewed, practical knowledge from first-line otolaryngologists in China, the United States, and Brazil were reviewed and collated. It was recommended that otolaryngology professionals should improve screening in suspected patients with relevant nasal and pharyngeal symptoms and signs, suspend non-emergency consultations and examinations in clinics, and rearrange the working procedures in operating rooms. The guidelines of personal protective equipment for swab sampling, endoscopy and surgery were listed. Indications for tracheotomy during the pandemic should be carefully considered to avoid unnecessary airway opening and aerosol-generation; precautions during surgery to reduce the risk of exposure and infection were illustrated. This review aimed to provide recommendations for otolaryngologists to enhance personal protection against COVID-19 and reduce the risk of nosocomial infection.

Respiratory Dysfunction in a Mouse Model of Spinocerebellar Ataxia 7

Spinocerebellar ataxia type 7 (SCA‐7) is a neurodegenerative polyglutamine disease within the family of spinocerebellar ataxias. Classically SCA7 is a disease of ataxia and vision loss. However, patients with SCA also have difficulty breathing, swallowing, coughing and maintaining a stable open airway which often result in fatal respiratory failure. While respiratory measures have been reported in other SCA mouse models, ventilation in a SCA‐7 mouse has not yet been studied. Using the SCA‐7 mouse model (Atxn7266Q/+) we sought to characterize the respiratory pathology of SCA‐7.Whole body plethysmography (WBP) was used to assess respiratory dysfunction in the Atxn7266Q/+ mouse both at baseline breathing (FiO2: 0.21; nitrogen balance) and during a hypercapnic and hypoxic challenge (Fi:CO2: 0.07, FiO2: 0.10; nitrogen balance). Neurobehavioral testing and strength was assessed using the inverted screen test and the grip strength test. Post mortem histological analysis was performed on the phrenic and hypoglossal motor neurons and nerves.At 4 weeks of age, the SCA‐7 mice are indistinguishable from their unaffected littermates. However, by 8 weeks of age, SCA‐7 mice perform poorly on both neurobehavioral and strength tests as compared to their WT littermates. 50% of the SCA‐7 mice died by 9 weeks, while littermate controls thrived. SCA‐7 mice have elevated respiratory rate at baseline, as well as reduced tidal volume, minute ventilation, peak inspiratory flow, peak expiratory flow, and inspiratory time during the respiratory challenge. These results indicate that the SCA‐7 mice have respiratory dysfunction. To understand the respiratory deficits, ongoing studies are histologically analyzing the diaphragm neuromuscular junction, phrenic and hypoglossal nerves, as well as phrenic and hypoglossal motor nuclei. Preliminary nerve analysis of the hypoglossal and phrenic nerves reveals significant axonal pathology. In conclusion, WBP analysis and preliminary histological nerve data reveals respiratory dysfunction in the Atxn7266Q/+ mouse model.Support or Funding Information Funding: R01 HD099486‐01; 1R21NS098131‐01

Malignant Melanoma Metastasis to the Thyroid Gland Causing Severe Central Airway Obstruction.

Metastasis of malignant melanoma to the thyroid gland causing airway obstruction is an extremely rare condition. In an 80-year-old woman who presented with painless swelling of the neck, a diagnosis of malignant melanoma metastasis to the thyroid gland with an unknown source was established. She received multiple radiotherapy sessions that resulted in occasional regression but not complete resolution. She was then referred for tracheal stenting owing to progressed dysphagia and dyspnea. Rigid bronchoscopy was performed, and a fully covered metal stent was placed to secure the open airway. Dyspnea improved immediately after stent insertion. The patient died at her residence because of a cerebrovascular event 2 weeks after the procedure. To the best of our knowledge, central airway obstruction due to malignant melanoma metastasis to the thyroid gland has been not reported in the literature. The approach for palliation of obstruction is similar to that of other malignant central airway obstructions.

Quantifying Regional Lung Deformation Using Four-Dimensional Computed Tomography: A Comparison of Conventional and Oscillatory Ventilation.

Mechanical ventilation strategies that reduce the heterogeneity of regional lung stress and strain may reduce the risk of ventilator-induced lung injury (VILI). In this study, we used registration of four-dimensional computed tomographic (4DCT) images to assess regional lung aeration and deformation in 10 pigs under baseline conditions and following acute lung injury induced with oleic acid. CT images were obtained via dynamic axial imaging (Siemens SOMATOM Force) during conventional pressure-controlled mechanical ventilation (CMV), as well as high-frequency and multi-frequency oscillatory ventilation modalities (HFOV and MFOV, respectively). Our results demonstrate that oscillatory modalities reduce intratidal strain throughout the lung in comparison to conventional ventilation, as well as the spatial gradients of dynamic strain along the dorsal-ventral axis. Harmonic distortion of parenchymal deformation was observed during HFOV with a single discrete sinusoid delivered at the airway opening, suggesting inherent mechanical nonlinearity of the lung tissues. MFOV may therefore provide improved lung-protective ventilation by reducing strain magnitudes and spatial gradients of strain compared to either CMV or HFOV.

Issue Information

Cover image: Artwork commissioned for the study in Blake et al pp 281–288, which was facilitated by the Indigenous Respiratory Outreach Care (IROC) Program. Artist Susie Klein.The background of this painting is looking down an open airway. The metallic coloured marks represent the specialists who care for and manage disease. The painting displays airflow using Indigenous flag coloured lines which are either being breathed in or exhaled out of the airway. You will find a number of communities reflected in the rough patches on the painting to coincide with the rural and remote locations throughout Queensland where IROC outreach clinics are conducted and the damage each community sustains with this disease.Image courtesy: Tamara L. Blake image

Effect of oxygen fraction on airway rescue: a computational modelling study

BackgroundDuring induction of general anaesthesia, patients frequently experience apnoea, which can lead to dangerous hypoxaemia. An obstructed upper airway can impede attempts to provide ventilation. Although unrelieved apnoea is rare, it continues to cause deaths. Clinical investigation of management strategies for such scenarios is effectively impossible because of ethical and practical considerations. MethodsA population-representative cohort of 100 virtual (in silico) subjects was configured using a high-fidelity computational model of the pulmonary and cardiovascular systems. Each subject breathed 100% oxygen for 3 min and then became apnoeic, with an obstructed upper airway, during induction of general anaesthesia. Apnoea continued throughout the protocol. When arterial oxygen saturation (Sao2) reached 20%, 40%, or 60%, airway obstruction was relieved. We examined the effect of varying supraglottic oxygen fraction (Fo2) on the degree of passive re-oxygenation occurring without tidal ventilation. ResultsRelief of airway obstruction during apnoea produced a single, passive inhalation (caused by intrathoracic hypobaric pressure) in all cases. The degree of re-oxygenation after airway opening was markedly influenced by the supraglottic Fo2, with a supraglottic Fo2 of 100% providing significant and sustained re-oxygenation (post-rescue Pao2 42.3 [4.4] kPa, when the airway rescue occurred after desaturation to Sao2 60%). ConclusionsSupraglottic oxygen supplementation before relieving upper airway obstruction improves the effectiveness of simulated airway rescue. Management strategies should be implemented to assure a substantially increased pharyngeal Fo2 during difficult airway management.

Respiratory mechanics during initial lung aeration at birth in the preterm lamb.

Despite recent insights into the dynamic processes during lung aeration at birth, several aspects remain poorly understood. We aimed to characterize changes in lung mechanics during the first inflation at birth and their relationship to changes in lung volume. Intubated preterm lambs (gestational age, 124-127 days; n = 17) were studied at birth. Lung volume changes were measured by electrical impedance tomography (VLEIT). Respiratory system resistance (R5) and oscillatory compliance (Cx5) were monitored with the forced oscillation technique at 5 Hz. Lambs received 3-7 s of 8 cmH2O of continuous distending pressure (CDP) before delivery of a sustained inflation (SI) of 40 cmH2O. The SI was then applied until either Cx5 or the VLEIT or the airway opening volume was stable. CDP was resumed for 3-7 s before commencement of mechanical ventilation. The exponential increases with time of Cx5 and VLEIT from commencement of the SI were characterized by estimating their time constants (τCx5 and τVLEIT, respectively). During SI, a fast decrease in R5 and an exponential increase in Cx5 and VLEIT were observed. Cx5 and VLEIT provided comparable information on the dynamics of lung aeration in all lambs, with τCx5 and τVLEIT being highly linearly correlated (r2 = 0.87, P < 0.001). Cx5 and VLEIT decreased immediately after SI. Despite the standardization of the animal model, changes in Cx5 and R5 both during and after SI were highly variable. Lung aeration at birth is characterized by a fast reduction in resistance and a slower increase in oscillatory compliance, the latter being a direct reflection of the amount of lung aeration.

Grading of Bag-Mask Ventilation Difficulty and Association with Unanticipated Difficult Laryngoscopy/Intubation in Children at a Training Center University Hospital: A Prospective Cohort Study

Objective: In children, the grading of Bag-Mask Ventilation (BMV) difficulty and its association with difficult laryngoscopy/intubation has not been well established. This study aimed to evaluate the grading for BMV difficulty and determine its association with difficult laryngoscopy/intubation in a normal airway pediatric population. Methods: This prospective cohort study was conducted in children aged ≤9 years who underwent general anesthesia and oroendotracheal tube intubation between September 2008 and December 2012. Difficult laryngoscopy was defined as a Cormack–Lehane laryngoscopic view grade of 3 or 4. Difficult intubation was defined as the occurrence of at least two of the following: 1) at least three intubation attempts using direct laryngoscopy by experienced personnel (excluding first intubation attempts); 2) intubation time >300 s; and 3) occurrence of desaturation (SpO2<95%). The use of open airway maneuvers, including continuous positive airway pressure (CPAP), oropharyngeal airway (OPA), and two-person ventilation (TPV), or unsuccessful BMV were also considered. The association between BMV difficulty and difficult laryngoscopy/intubation was assessed using multivariate logistic regression with adjusted odds ratios (OR), 95% confidence intervals (CIs), and area under the receiver operating characteristic curve (AUC). Results: The incidence of difficult laryngoscopy/intubation was 6.4% (49/765). The categories of BMV difficulty were grade 0 (easy BMV without requiring an open airway maneuver, n=308), grade 1 (easy BMV after applying CPAP, n=368), grade 2 (successful BMV after inserting an OPA, n=16), grade 3 (successful BMV after applying TPV, n=71), and grade 4 (unsuccessful BMV after applying all airway maneuvers, n=2). Difficult BMV was defined as a BMV grade of 3 or 4 (v/s grades 0-2). After adjusting for age, body weight, history of snoring, type of operation, use of neuromuscular blocking agents, and first laryngoscopist, BMV difficulty was significantly associated with difficult laryngoscopy/intubation (adjusted OR [95% CI]=2.5 [1.1-5.5], sensitivity 0.59, specificity 0.74, AUC=0.70). Conclusion: A BMV grade of 3 (requiring TPV) or 4 (unsuccessful BMV) was associated with difficult laryngoscopy/ intubation in a pediatric population.

Concurrent Validity of the Static and Dynamic Measures of Inspiratory Muscle Strength: Comparison between Maximal Inspiratory Pressure and S-Index.

ObjectiveTo verify the concurrent validity between the inspiratory muscle strength (IMS) values obtained in static (maximal inspiratory pressure [MIP]) and dynamic (S-Index) assessments.MethodsHealthy individuals were submitted to two periods of evaluation: i) MIP, static maneuver to obtain IMS, determined by the Mueller’s maneuver from residual volume (RV) until total lung capacity (TLC); ii) and S-Index, inspiration against open airway starting from RV until TLC. Both measures were performed by the same evaluator and the subjects received the same instructions. Isolated maneuvers with differences < 10% were considered as reproducible measures.ResultsData from 45 subjects (21 males) were analyzed and that showed statistical difference between MIP and S-Index values (133.5 ± 33.3 and 125.6 ± 32.2 in cmH2O, respectively), with P=0.014. Linear regression showed r2=0.54 and S-Index prediction formula = 39.8+(0.75×MIP). Pearson’s correlation demonstrated a strong and significant association between the measures with r=0.74. The measurements showed good concordance evidenced by the Bland-Altman test.ConclusionS-Index and MIP do not present similar values since they are evaluations of different events of the muscular contraction. However, they have a strong correlation and good agreement, which indicate that both are able to evaluate the IMS of healthy individuals.

Virtues of Using a Double Lumen Tube for Anesthesia in Patients with Endobronchial Tumours Requiring Open Lung Resection or Bronchoplastic Procedures

Objective The benefits and risks of using double lumen tube (DLT) in open thoracotomy are not well studied and the relative contraindication for using it in cases of endobronchial tumours is not proven. In this study, we compared our experience with using DLT versus single lumen tube (SLT) for anesthesia in patients requiring an open thoracotomy for resection of endobronchial tumours. Methods A prospective observational study was performed in a single tertiary care university hospital in patients with endobronchial tumours anesthetized with single and double lumen tubes for open thoracotomy procedures over a period from 2010 till 2018. Results One hundred and six patients with endobronchial tumours were studied. There were 76 males. Median age was 32 years (14 - 62). In 96 cases, endobronchial pathology was a typical carcinoid. 58 patients were anesthetized using a DLT and 48 using a SLT. Four cases of near miss from potentially fatal intraoperative tumour migration occurred in the SLT group (p = 0.025). There was only one case of mild tumour bleeding from the DLT group and time of insertion was longer (16.2 vs. 4.5 min p Conclusions We conclude that it is safe to place a double lumen endo tracheal tube for patients with endobronchial tumours requiring open lobectomies or bronchoplastic procedures. An additional benefit of DLT use is increasing surgical satisfaction by reducing spillage and tidal volume loss during surgical anastomosis of the open airway.

Management of Palatal Fracture and Airway Challenge in A Child — A Red Flag

Airway managements in maxillofacial fracture patients are complex and crucial. Trauma to the maxillofacial region may cause hemorrhage, swelling which may lead to pulmonary aspiration and airway obstruction. Airway managements in maxillofacial fracture patients are complex and crucial. Besides being uncooperative, presence of fractures and soft tissue injuries posed challenges in managing pediatric patient who already have smaller airway opening. This condition is an important red flag which required extra caution from the treating clinicians. A 6-year-old boy was involved in a road traffic accident and presented with profuse bleeding from the oral cavity and nostrils. Physical examination showed oozing of blood with step deformity of the midpalate. Multiple attempts in intubation resulted in failure before succeeding with the aid of suction devices. After intubation was done, intraoral bleeding was successfully managed with transpalatal wiring and nasal packing. The patient was ventilated in the intensive care unit and was extubated two days later. He was discharged well from hospital after one week of admission. Airway management is a rush against time, particularly in a pediatric patient suffering from a palatal fracture. The need for helping hands for suction and child control must be emphasized to ensure the patient’s survival.

To enhance the quality of CPR performed by youth layman

BackgroundBy educating laymen, survival after cardiac arrest can increase in society. It is difficult to reach the entire population with cardiopulmonary resuscitation (CPR) training. However, if 15% of the population knows how to perform CPR, an increase in short- and long-term survival in patients suffering a cardiac arrest could be seen. To educate youth is a way to reach parts of the population. This study aimed to investigate the effect of a 2-h CPR intervention for youth.MethodsData were collected through an intervention utilizing simulation and consisted of a pre- and post-assessment of 50 participants’ CPR performance.ResultsThe participants’ compression depths are, after training, within guidelines. However, the compression rate increases from within limits (117) to become too fast (128). The range of the minimum compression rate rises from 70 to 92 which is an improvement. The ventilation volume increases from 112 ml in pre-test to 579 ml in post-test. In the pre-test, 88% of the participants did not succeed in securing an open airway; only six participants succeeded in securing an open airway. In the post-test, 49% of the participants underperform in the ventilation. However, only 12 participants failed in securing an open airway in the post-test. Compression recoil and hand position marginally improved from pre- to post-test.ConclusionEducating young people at school is one way to disseminate CPR knowledge in society. In this study, the ventilation of the patient arose as a major weakness. To be able to establish an open airway and ventilate the patient with the correct volume as well as to overcome the psychological barrier to initiate mouth-to-mouth ventilation seems to require more than 2 h training. The training may need to consist of repeated sessions over the year with feedback, to give young people the skills to perform CPR with good quality.

Muscarinic Inhibition of Hypoglossal Motoneurons: Possible Implications for Upper Airway Muscle Hypotonia during REM Sleep.

Proper function of pharyngeal dilator muscles, including the genioglossus muscle of the tongue, is required to maintain upper airway patency. During sleep, the activity of these muscles is suppressed, and as a result individuals with obstructive sleep apnea experience repeated episodes of upper airway closure when they are asleep, in particular during rapid-eye-movement (REM) sleep. Blocking cholinergic transmission in the hypoglossal motor nucleus (MoXII) restores REM sleep genioglossus activity, highlighting the importance of cholinergic transmission in the inhibition of hypoglossal motor neurons (HMNs) during REM sleep. Glutamatergic afferent input from neurons in the parahypoglossal (PH) region to the HMNs is critical for MoXII respiratory motor output. We hypothesized that state-dependent cholinergic regulation may be mediated by this pathway. Here we studied the effects of cholinergic transmission in HMNs in adult male and female mice using patch-clamp recordings in brain slices. Using channelrhodopsin-2-assisted circuit mapping, we first demonstrated that PH glutamatergic neurons directly and robustly activate HMNs (PHGlut → HMNs). We then show that carbachol consistently depresses this input and that this effect is presynaptic. Additionally, carbachol directly affects HMNs by a variable combination of muscarinic-mediated excitatory and inhibitory responses. Altogether, our results suggest that cholinergic signaling impairs upper airway dilator muscle activity by suppressing glutamatergic input from PH premotoneurons to HMNs and by directly inhibiting HMNs. Our findings highlight the complexity of cholinergic control of HMNs at both the presynaptic and postsynaptic levels and provide a possible mechanism for REM sleep suppression of upper airway muscle activity.SIGNIFICANCE STATEMENT Individuals with obstructive sleep apnea can breathe adequately when awake but experience repeated episodes of upper airway closure when asleep, in particular during REM sleep. Similar to skeletal postural muscles, pharyngeal dilator muscles responsible for maintaining an open upper airway become hypotonic during REM sleep. Unlike spinal motoneurons controlling postural muscles that are inhibited by glycinergic transmission during REM sleep, hypoglossal motoneurons that control the upper airway muscles are inhibited in REM sleep by the combination of monoaminergic disfacilitation and cholinergic inhibition. In this study, we demonstrated how cholinergic signaling inhibits hypoglossal motoneurons through presynaptic and postsynaptic muscarinic receptors. Our results provide a potential mechanism for upper airway hypotonia during REM sleep.

A novel, low fidelity simulator for laryngotracheal reconstruction

IntroductionOpen airway reconstruction is a highly specialized skill. Simulation affords the opportunity to practice surgical skills in a low stakes environment which is particularly important for a high acuity, low frequency operation. Although animal models have been described, these present ethical and financial barriers, and therefore are not ideal to expose residents to airway reconstruction techniques. To our knowledge there is not a commercially available simulator for laryngotracheal reconstruction. ObjectivesThis study describes a novel, low-fidelity simulation technique for laryngotracheal reconstruction using a cartilage graft. MethodsWe designed a low-fidelity simulator to represent the trachea, esophagus, and cartilage graft using tubing from a Luken's trap, vinyl backwash hose, and pig's ears from a non-specialty grocery store. The model was evaluated with a Likert scale (1 = strongly disagree to 5 = strongly agree). ResultsTwelve participants attended simulation sessions. Participants reported a mean score (+/-SD) 4.25 ± 0.75 that the tissue characteristics were adequate and 4.50 ± 0.79 that sutures could be placed. There was universal strong agreement that the tissue could be manipulated appropriately (5 ± 0). The cost per resident was less than 4 dollars. ConclusionWe present a readily available, easy to construct, and low cost simulation model for open airway reconstruction that can be used as a stand-alone simulator or in preparation for an animal dissection course. Our participants reported that the model had acceptable tissue characteristics to practice performing laryngotracheal reconstruction with a cartilage graft.

High oxygen fraction during airway opening is key to effective airway rescue in obese subjects.

Apnea is common after induction of anesthesia and may produce dangerous hypoxemia, particularly in obese subjects. Optimal management of airway emergencies in obese, apneic subjects is complex and controversial, and clinical studies of rescue strategies are inherently difficult and ethically-challenging to perform. We investigated rescue strategies in various degrees of obesity, using a highly-integrated, computational model of the pulmonary and cardiovascular systems, configured against data from 8 virtual subjects (body mass index [BMI] 24-57 kg m-2). Each subject received pre-oxygenation with 100% oxygen for 3 min, and then apnea with an obstructed airway was simulated until SaO2 reached 40%. At that time, airway rescue was simulated, opening of the airway with the provision of various patterns of tidal ventilation with 100% oxygen. Rescue using tidal ventilation with 100% oxygen provided rapid re-oxygenation in all subjects, even with small tidal volumes in subjects with large BMI. Overall, subjects with larger BMI pre-oxygenated faster and, after airway obstruction, developed hypoxemia more quickly. Our results indicate that attempts to achieve substantial tidal volumes during airway rescues are probably not worthwhile (and may be counter-productive); rather, it is the assurance of a high-inspired oxygen fraction that will prevent critical hypoxemia.

Airway Closure during Surgical Pneumoperitoneum in Obese Patients.

Airway closure causes lack of communication between proximal airways and alveoli, making tidal inflation start only after a critical airway opening pressure is overcome. The authors conducted a matched cohort study to report the existence of this phenomenon among obese patients undergoing general anesthesia. Within the procedures of a clinical trial during gynecological surgery, obese patients underwent respiratory/lung mechanics and lung volume assessment both before and after pneumoperitoneum, in the supine and Trendelenburg positions, respectively. Among patients included in this study, those exhibiting airway closure were compared to a control group of subjects enrolled in the same trial and matched in 1:1 ratio according to body mass index. Eleven of 50 patients (22%) showed airway closure after intubation, with a median (interquartile range) airway opening pressure of 9 cm H2O (6 to 12). With pneumoperitoneum, airway opening pressure increased up to 21 cm H2O (19 to 28) and end-expiratory lung volume remained unchanged (1,294 ml [1,154 to 1,363] vs. 1,160 ml [1,118 to 1,256], P = 0.155), because end-expiratory alveolar pressure increased consistently with airway opening pressure and counterbalanced pneumoperitoneum-induced increases in end-expiratory esophageal pressure (16 cm H2O [15 to 19] vs. 27 cm H2O [23 to 30], P = 0.005). Conversely, matched control subjects experienced a statistically significant greater reduction in end-expiratory lung volume due to pneumoperitoneum (1,113 ml [1,040 to 1,577] vs. 1,000 ml [821 to 1,061], P = 0.006). With airway closure, static/dynamic mechanics failed to measure actual lung/respiratory mechanics. When patients with airway closure underwent pressure-controlled ventilation, no tidal volume was inflated until inspiratory pressure overcame airway opening pressure. In obese patients, complete airway closure is frequent during anesthesia and is worsened by Trendelenburg pneumoperitoneum, which increases airway opening pressure and alveolar pressure: besides preventing alveolar derecruitment, this yields misinterpretation of respiratory mechanics and generates a pressure threshold to inflate the lung that can reach high values, spreading concerns on the safety of pressure-controlled modes in this setting.

Three Dimensional Rhinoplasty and Nasal Airway Improvement in Cleft-Nose Deformity.

Septorhinoplasty is particularly challenging among revision surgeries for cleft sequelae. The challenge of cleft septorhinoplasty is mainly due to the complex anatomy of nose, deformity of each of its components and the difficulty and lack of clarity in surgical management. From 2014 to 2017, 26 patients with cleft lip nose deformity were operated by the same cleft team. The study was conducted to assess the improvement in nasal airway and appearance following secondary rhinoplasty with extracorporeal septoplasty. Post operatively each patient was evaluated using the standard modified rhinoplasty outcome evaluation questionnaire, a validated instrument that aids in stratifying patients according to their subjective response. All patients reported great relief of nasal obstruction and improved breathing. More than 80% of our patients were satisfied with improved aesthetics and reported better self-confidence. Secondary cleft rhinoplasty with extracorporeal septoplasty surgery significantly improves the cosmesis and nasal airway opening, subsequently giving them improved self-confidence.

Solitary Fibrous Tumor of the Larynx and Anterior Neck

Whether benign or malignant, laryngeal and neck masses may involve the upper airway and obstruct breathing. While surgically-resectable malignancies are generally extirpated with adequate margins of normal tissue, benign lesions are usually excised conservatively. However, even benign masses may behave malignantly, necessitating more aggressive surgical resection. We present one such case.&#x0D; &#x0D; CASE REPORT&#x0D; &#x0D; A 35-year-old man from Cotabato City consulted due to difficulty of breathing. He had a six-year history of progressively enlarging anterior neck mass with intermittent dyspnea, foreign body sensation, progressive dysphagia and hoarseness over the last three months. Physical examination revealed a well-defined, 5 x 6 cm smooth, firm, non-tender anterior neck mass that moved with deglutition. Rigid endoscopy showed a right supraglottic mass with bulging of the right glottic and subglottic area, with a less than 10% airway opening. (Figure 1A) Both arytenoids were visibly mobile, but glottic closure was impaired. (Figure 1B) Tracheostomy and suspension laryngoscopy with biopsy yielded inconclusive results (fibromuscular tissue) and fine needle aspiration cytology (FNAC) of the anterior neck mass only revealed blood and colloid. Contrast computed tomography of the neck showed a well-marginated, hypodense, thick-walled, heterogeneously enhancing mass in the right laryngeal fossa measuring 2.86 x 1.78 cm with a larger extension anteriorly measuring 4.66 x 2.52 cm. Effacement of the epiglottis and aryepiglottic fold was noted. The hyoid and thyroid cartilage were intact, and the thyroid gland was normal. (Figure 2A, B)&#x0D; &#x0D; Because of inconclusive histopathological and cytological results, an incision biopsy of the anterior neck mass was performed. Histopathological evaluation revealed spindle cell mesenchymal proliferation, and immunohistochemical stains showed positive immunoreactivity for CD34, with a weakly positive S-100 and negative SMA, favoring a solitary fibrous tumor.&#x0D;