No abstract available.
Airway Resistance*

No abstract available.
Airway Resistance* ; Oscillometry*

No abstract available.
Airway Resistance* ; Respiration*

OBJECTIVE: To study the influence of disposable respiratory filter on the results of impulse oscillometery. METHODS: 90 healthy subjects were randomly selected and impulse oscillometery results were taken repeatedly through disposable respiratory filter and control device. All results were statistically analyzed. RESULTS: When using the disposable respiratory filter, respiratory impedance (Zrs) and resistance at all frequency (R5Hz-R35Hz) were significantly increased compared with the control device (P<0.01). The two measurements had a significant linear correlation (P<0.01) and a regression equation was established. The disposable respiratory filter did not exist in statistic difference to response frequency (Fres) and the elastic resistance (X5Hz-X15Hz) at all frequency(P>0.05). CONCLUSIONS The disposable respiratory filter can be used when testing pulmonary compliance, chest wall disease and obstruction outside the airway in impulse oscillometery system to avoid infection and ensure quality.
Airway Resistance ; Filtration/instrumentation* ; Humans ; Oscillometry

Endotracheal intubation has been a routine practice in general anesthesia and is accepted by anesthetiste and surgeons as an integral part of airway management during anesthesia and operation. Paradoxically however, there have been several cases of obstruction of the airway which occurred due to endotracheal intubation. The authors experienced two cases of airway obstruction due tendotracheal and endobronchial techniques, using tubes with malfunctioning cuffs. The lumen of an endotracheal tube was collapsed by intracuff pressure, shortly after inflation of the cuff and resulted in extremely high airway resistance. In the other case, gradual leakage of air from the distal cuff of a Carlens tube led to collapse of the distal cuff. This promoted the movement of blood, secretions, and pus from the diseased right lung to the normal healthy left lung in association with the left lateral recumbent position, which in turn resulted in total airway obstruction.
Airway Management ; Airway Obstruction ; Airway Resistance ; Anesthesia ; Anesthesia, General ; Inflation, Economic ; Intubation, Intratracheal* ; Lung ; Suppuration ; Surgeons

Active anterior rhinomanometry (AAR) was performed in 42 patients with low-profile or saddle noses before augmentation rhinoplasty (AR) and after AR. The purpose was to measure nasal airway resistance (NAR) and nasal airflow (NAF). There were 38 females and 4 males, whose ages ranged from 15 to 42 years (mean 29.6 years). Preoperative total NAR at 75 Pascals (Pa) was 0.24+/-0.09 and 0.20+/-0.06 Pa/ml/sec for the non-decongested and decongested value respectively. Two weeks postoperatively, the total NAR was 0.19+/-0.06 and 0.15+/-0.05 Pa/ml/sec for the non-decongested and decongested value respectively, which was significantly less than the preoperative value. The postoperative total NAF was 422.31+/-137.05 cm3 and 514. 57+/-152.45 cm3 for the non-decongested and decongested value respectively, which was significantly increased when compared to the preoperative value (342.57+/-109.27 cm3 and 399.90+/-106.98 cm3 for the non-decongested and decongested value respectively). The comparison between the changes in NAR and subjective nasal breathing showed that the postoperative NAR decreased in 88.10% of patients while subjective nasal breathing improved in only 52.38%. Postoperative NAR increased in 9.52% of patients, while subjective nasal breathing was worsened in 2.38%. The results of this study indicate that AR has decreased the NAR and increased NAF, and thus improving the nasal breathing. From this preliminary study it is concluded that AR is useful not only for the aesthetic aspect but also for its effect on the function of the nose, especially on the improvement of nasal breathing.
Airway Resistance* ; Female ; Humans ; Male ; Nose ; Respiration ; Rhinomanometry ; Rhinoplasty*

PURPOSE: This study was intended to perform cephalometric comparison between the patients with and without obstructive sleep apnea (OSA). The factors influencing the OSA in the lateral cephalogram was also investigated. PATIENT AND METHOD: Twenty four patients who visited Sleep Disorder Clinic in Dongsan Medical Center, Keimyung University and evaluated with polysomnograph(PSG) and cephalogram were included in the study. The patients had apnea-hypopnea episode(AHI) over 10 times per hour was diagnosed as OSA after overnight PSG. To evaluate hard and soft tissue profile, cephalometric radiogram were taken at maximal intercuspation(P1) and mandibular protruding position(P2). The diffefence between the OSA and normal group were evaluated statistically and the stepwise regression analysis was applied to analyse the cephalometric influencing factors to OSA. RESULT: The OSA Group(n=14) had significantly higher Body Mass Index(BMI) than control group(n=10). Lower facial height(ANSGn) was longer in OSA group. However statistically significant difference was not detected in other anteroposterior craniofacial measurements. The soft palate lenth (PNS-P), hyoid position (MP-Hyoid) had positive correlation between AHI (r=0.496, r=0.413, respectively, p<0.05). However, the measurements of oropharyngeal airway was not different between the two groups. The hypothesis, the antero-posteriorly narrow oropharyngeal airway might aggravate the airway resistance and can give rise to higher AHI, was not accepted in the study. This can be attributed by inclusion of the patients performed uvulopalatopharyngoplasty because of the tonsilar or soft palate hypertrophy in the present study. The results of regression analysis revealed that PNS-P, upper airway width(Nph1), upper facial heght(N-ANS), and lower facial height(ANS-Gn) could influence the degree of AHI (F value < 0.0001, R2 = 0.829). CONCLUSION: We suggest lateral cephalogram may utilized as a useful method to evaluate OSA. The patient with long soft palate, narrow upper airway width, long upper and lower facial height can be expected to have high risk of OSA. However, it should be emphasized the comphrehensive intraoral inspection including soft palate and tonsilar hypertrophy because lateral cepahlogram cannot visualize oropharyngeal status completely.
Airway Resistance ; Humans ; Hypertrophy ; Palate, Soft ; Sleep Apnea, Obstructive*

Heat-moisture exchanger (HME) is an inexpensive and effective device used to prevent respiratory complications that can be caused by endotracheal tube insertion during general anesthesia. But, HME can increase airway resistance and be occluded by the patient's secretions. Whether a HME could be occluded by clear fluids such as condensate in the airway circuit is not certain yet. In vitro, a case of HME occlusion by normal saline was reported. We report a case of HME obstruction by distilled water came from the heated wire circuit which was unintentionally connected to the HME.
Airway Resistance ; Anesthesia, General ; Hot Temperature ; Porphyrins ; Water

Laryngeal mask airways (LMAs) have several advantages compared with conventional endotracheal tube (ETT) in tracheal surgery. LMAs cannot penetrate the airway below the level of the glottis, but enable the access to the larynx and tracheobronchial tree while avoiding airflow impairment, tracheal stimulation, trauma, and the interference of tracheal mucosal blood flow. Moreover, LMAs have lower airway resistance than ETTs. We describe the use of a proseal laryngeal mask airway (PLMA) in patients with high grade upper tracheal stenosis. We suggest that PLMA might have advantages over the classic LMA by preventing aspiration and by allowing the evacuation of air from the stomach in high-grade upper tracheal stenosis.
Airway Resistance ; Glottis ; Humans ; Laryngeal Masks* ; Larynx ; Stomach ; Tracheal Stenosis*

BACKGROUND: Bronchofiberscopy is a procedure with a chance of airway irritation and it may cause pathophysiologic changes of respiratory system. So we tried to evaluate the influence of bronchofibercopy on O2 saturation, ABGA and PET by patient's basal status and procedure type. METHOD: O2 saturation was measured every 1 minute from the left index finger tip with percutaneous oximetry. ABGA was done before and right after the bronchofiberscopy and PFT was done before and within 10 minutes after the bronchofiberscopy. RESULTS: The mean time for bronehofiberscopy procedure was 14.5mim and SaO2 maximally fall to 89.0 below 8% of the baseline after mean time of 8.4mm, which was recorvered at the end of the procedure. SaO2 change amount was 8.4% on Non-O2 supply group, which was lower compared to 6.4% of the O2-supply group without statistically significance. Biopsy Group and BAL group showed more SaO2 fall than washing only group. The level of PaO2 and FEV1 of the patient didn's influence significantly on SaO2 fall during the procedure. ABGA taken before and after the bronchofiberscopy showed mild fall of Pa02 and mild rise of PaCO2. Whereas PET showed decrease of FEV1(P<0.05) and increase of RV without changes in airway resistance and pulmonary diffusion capacity. Comparing before and after the bronchofiberscopy, the washing group showed no significant changes on PET, while the biopsy group and the BAL group showed increase of RV & decrease of FEV1 after the bronchofiberscopy. BAL group showed more changing tendency rather than biopsy group although not statistically significant. CONCLUSION: Bronchofiberscopy is considered as a relatively safe procedure, but it would be better to be done with O2 supply especially in the patient with low PaO2 and in the case of biopsy and BAL
Airway Resistance ; Biopsy ; Diffusion ; Fingers ; Humans ; Oximetry ; Respiratory System