Comparison of micron- and nano-particle transport in the human nasal cavity with a focus on the olfactory region

Intranasal administration of drugs serves as a promising, noninvasive option for the treatment of various disorders of the central nervous system and upper respiratory tract. Predictive, ie, realistic and accurate, particle tracking in the human nasal cavities is an essential step to achieve these goals. The major factors affecting aerosol transport and deposition are the inhalation flowrate, the particle characteristics, and the nasal airway geometry. In vivo and in vitro studies using nasal cavity casts provide realistic images regarding particle-deposition pattern. Computational Fluid-Particle Dynamics (CF-PD) studies can offer a flexible, detailed and cost effective solution to the problem of direct drug delivery. The open-source software OpenFOAM was employed to conduct, after model validation, laminar and turbulent fluid-particle dynamics simulations for representative nasal cavities. Specifically, micron particles and nanoparticles were both individually tracked for different steady airflow rates to determine sectional deposition efficiencies. For micron particles, inertial forces were found to be the dominating factor, resulting in higher deposition for larger particles, mainly due to impaction. In contrast, diffusional effects are more important for nanoparticles. With a focus on the olfactory region, the detailed analysis of sectional deposition concentrations, considering a wide range of particle diameters, provide new physical insight to the particle dynamics inside human nasal cavities. The laminar/turbulent Euler-Lagrange modelling approach for simulating the fate of nanoparticles form a foundation for future studies focusing on targeted drug delivery. A major application would be direct nanodrug delivery to the olfactory region to achieve large local concentrations for possible migration across the blood-brain-barrier.

Rorqual whale nasal plugs: protecting the respiratory tract against water entry and barotrauma

The upper respiratory tract of rorquals, lunge-feeding baleen whales, must be protected against water incursion and the risk of barotrauma at depth, where air-filled spaces like the bony nasal cavities may experience high adverse pressure gradients. We hypothesize these two disparate tasks are accomplished by paired cylindrical nasal plugs that attach on the rostrum and deep inside the nasal cavity. Here, we present evidence that the large size and deep attachment of the plugs is a compromise, allowing them to block the nasal cavities to prevent water entry while also facilitating pressure equilibration between the nasal cavities and ambient hydrostatic pressure (Pamb) at depth. We investigated nasal plug behaviour using videos of rorquals surfacing, plug morphology from dissections, histology and MRI scans, and plug function by mathematically modelling nasal pressures at depth. We found each nasal plug has three structurally distinct regions: a muscular rostral region, a predominantly fatty mid-section and an elastic tendon that attaches the plug caudally. We propose muscle contraction while surfacing pulls the fatty sections rostrally, opening the nasal cavities to air, while the elastic tendons snap the plugs back into place, sealing the cavities after breathing. At depth, we propose Pamb pushes the fatty region deeper into the nasal cavities, decreasing air volume by about half and equilibrating nasal cavity to Pamb, preventing barotrauma. The nasal plugs are a unique innovation in rorquals, which demonstrate their importance and novelty during diving, where pressure becomes as important an issue as the danger of water entry.

Characteristics and outcome of impacted button batteries among young children less than 7 years of age in China: a retrospective analysis of 116 cases

BACKGROUND

Ingestion of button batteries occurs in about ten persons per one million persons each year, with most of them children, and one in every 1000 battery ingestions leads to serious injuries. This study aimed to describe the clinical features and outcome of ingestion or inhalation of button batteries in children spanning a decade from January, 2006 to December, 2016 at a tertiary care hospital.

METHODS

We reviewed the clinical records of children who sought treatment for inhaled or ingested button batteries at our hospital during the study period. Data on gender, age, time from ingestion to treatment, site of impaction, imaging findings, and outcomes were retrieved and analyzed.

RESULTS

We identified 116 pediatric cases of ingestion or inhalation of button batteries. Their mean age was 26 months. The time from ingestion or inhalation of button batteries to treatment was 0.5 hours to 2 weeks. Ninety-seven (83.6%) button batteries were located in the nasal cavity, 13 (11.2%) in the gastrointestinal (GI) tract including 6 in the esophagus, and 7 in the stomach and lower GI tract, and 6 (5.2%) in the auditory tract. Twenty-one (21.6%) children with nasal button batteries had preoperative septal perforations and one (1.0%) had postoperative septal perforation. One child with esophageal button battery developed esophageal stricture and one died of sudden cardiac arrest perioperatively. One child had auditory damages in the right tympanic membrane and ossicles.

CONCLUSIONS

Inhalation or ingestion may occur in the nasal cavities, the esophagus and GI tract and the auditory tract. Prompt diagnosis and treatment are required for a satisfactory outcome and ingested or inhaled button batteries require different treatment protocols.

Nasal foreign bodies in children in a pediatric hospital in Senegal: A three-year assessment

OBJECTIVES

Nasal foreign bodies (NFB) constitute a common domestic accident in children. The objectives of the present study were to report the particularities of NFBs in children presenting at a pediatric hospital in Senegal, and to describe our therapeutic attitude.

MATERIAL AND METHODS

A retrospective descriptive study included all under-15 year-olds presenting with NFB in the ENT department of the National Children's Hospital Center of Diamniadio, Senegal, between January 1, 2013 and December 31, 2015. Study variables comprised: age, gender, provenance, presenting symptoms, time to consultation, type of NFB, extraction method, and complications.

RESULTS

58 NFB cases were retrieved. Mean age was 3years 4months; 93% of patients were under 5 years old. There was female predominance of 53.45%: i.e., sex-ratio, 0.87. Location was in the right cavity in 43 patients (74.1%). The presenting symptom was purulent rhinorrhea in 51.7% of cases. Time to consultation was within 24hours in 17.24% of cases. NFB type was firstly foam rubber (29.3%), followed by grain (20.7%). Extraction was performed in consultation in 84.5% of cases and in the operating room in 15.5%. Morbidity was 22.41%: 17.24% epistaxis and 5.17% nasal infection.

CONCLUSION

NFBs constitute a common domestic accident in under-5 year-olds. The rural Senegalese context shows delay in consultation.

Oestrus ovis larvae in nasal cavity of sheep: a case report

The present communication reports the infestation of nasal cavities of sheep by larvae of Oestrus ovis from Kashmir Valley.

Is there a correlation between nasal septum deviation and maxillary transversal deficiency? A retrospective study on prepubertal subjects

INTRODUCTION

Deviated nasal septum may cause a reduction of the nasal airflow, thus, during the craniofacial development, a reduced nasal airflow could originate a chronic mouth-breathing pattern, related with moderate to severe maxillary constriction. The aim of this retrospective study is to analyze the correlation between maxillary transverse deficiency and nasal septum deviation.

METHODS

Frontal cephalograms were performed on 66 posterior-anterior radiographs of subjects (34M, 32F; mean age 9.95±2.50 years) with maxillary transverse deficiency and on a control group of 31 posterior-anterior radiographs of subjects (13M, 18F; 9.29±2.08 years). Angular parameters of the nasal cavities were recorded and compared between the two groups using a Student's t-test.

RESULTS

Generally all the parameters are very similar between the two groups except for the ASY angle that differs for about the 27%; anyway the Student's t-test showed no statistically significant differences between the two groups (mostly p>0.20).

CONCLUSIONS

This study failed to show an association between transverse maxillary deficiencies and nasal septum deviations. Moreover, no significant differences were found between the mean nasal cavities dimensions in subjects with transverse maxillary deficiency and the control group.

Effects of CT resolution and radiodensity threshold on the CFD evaluation of nasal airflow

The article focuses on the robustness of a CFD-based procedure for the quantitative evaluation of the nasal airflow. CFD ability to yield robust results with respect to the unavoidable procedural and modeling inaccuracies must be demonstrated to allow this tool to become part of the clinical practice in this field. The present article specifically addresses the sensitivity of the CFD procedure to the spatial resolution of the available CT scans, as well as to the choice of the segmentation level of the CT images. We found no critical problems concerning these issues; nevertheless, the choice of the segmentation level is potentially delicate if carried out by an untrained operator.

Adenoid cystic carcinoma of the paranasal sinuses: retrospective series and review of the literature

OBJECTIVES

Adenoid cystic carcinomas (ACC) are rare malignant tumours arising in the major and minor salivary glands. Involvement of the nasal cavity and paranasal sinuses is rare and poorly described. The purpose of this study was to define the clinical and prognostic criteria of ACC of the paranasal sinuses based on the review of a series of 25 cases.

MATERIAL AND METHODS

Single-centre retrospective study of 25 cases of ACC of the paranasal sinuses managed between 1998 and 2011, evaluating epidemiological, clinical, diagnostic and prognostic criteria. Factors influencing survival (Kaplan-Meier/Log Rank test) and the patient's quality of life (EORTC QLQ-C30 questionnaire) were also analysed.

RESULTS

Most patients (72%) had a locally-advanced tumour (stage T3 or T4) at diagnosis. Tumour sites, in decreasing order of frequency, were the maxillary sinus, nasal cavities and ethmoid sinus. The most common presenting complaints were maxillary pain or heaviness, unilateral blocked nose, and repeated epistaxis. When the tumour was resectable, treatment comprised a combination of surgery and adjuvant radiotherapy. The 5-year overall survival rate was 63% and the 5-year disease-free survival rate was 43%. The TNM stage at diagnosis (P=0.03), the histological subtype (P=0.023), the possibility of combined surgery and radiotherapy (P=0.03), and local control (P=0.05) were significant factors of improved 5-year overall survival. Positive surgical margins were associated with a trend towards poorer 5-year disease-free survival (ns).

CONCLUSIONS

ACC are rare malignant tumours associated with a poor prognosis, characterized by a high recurrence rate. Recommended treatment is a combination of surgery and adjuvant radiotherapy whenever possible. Five-year survival varies as a function of TNM stage, histological subtype, treatment options and local control.