OBJECTIVETo investigate the obstructive site and the dynamic change of the upper airway in patients with obstructive sleep apnea hypopnea syndrome (OSAHS) during sleep and wakefulness.

METHODSAfter being deprived of sleeping for 20 hours, sequential midline sagittal images of the upper airway were obtained in 21 patients during sleep and wakefulness with dynamic MRI. The obstructive state was studied according to hypopnea (< 10 s) and apnea (> or = 10 s). The length of obstruction site was measured and the dynamic characteristics of obstruction was observed. Statistical analysis was performed with paired t-test.

RESULTSThe obstruction at the level of the palatopharynx in patients with hypopnea during wakefulness was similar to that in patients with apnea during sleep. The maximal length [(6.61 +/- 1.23) cm], the minimal length [(0.95 +/- 0.22) cm] and maximal length difference [(5.66 +/- 1.27) cm] related to apnea during sleep were longer than those correlated with hypopnea [(2.99 +/- 0.51) cm, (0.72 +/- 0.23) cm, (2.27 +/- 0.67) cm, respectively] in wakefulness. (P < 0.01).

CONCLUSIONSThe obstruction of upper airway during sleep is dynamic and multilevel in patients with OSAHS. To a certain degree, hypopnea during wakefulness can give a clue to the obstructive state during sleep.

Adult ; Airway Obstruction ; diagnosis ; physiopathology ; Female ; Humans ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Sleep Apnea, Obstructive ; diagnosis ; physiopathology

OBJECTIVE: To determine whether there was agreement between the short daytime ApneaGraph (dAG) and nocturnal ApneaGraph (nAG) in diagnosing sleep respiratory events initially and identifying the site of obstruction in airway. METHOD: Twenty four patients diagnosed OSAHS by PSG were enrolled. The apnea-hypopnea index (AHI), apnea index (AI), obstructive apnea-hypopnea index (OAHI), central apnea hypopnea index (CAHI), mixed apnea index (MAHI), lowest oxygen saturation (LSaO2) and the proportion of upper/lower obstruction (UPPER, LOWER) of patients were measured using both dAG and nAG. RESULT: There were no significant differences between nAG and dAG for the following parameters: AHI, AI, CAHI, MAHI, OAHI, the proportion of upper/lower obstruction, or LSaO2 (P>0.05). There were significant positive correlations between nAG and dAG with regard to AHI, AI, MAHI, OAHI, the proportion of upper/lower obstruction , LSaO2 except CAHI. CONCLUSION The dAG has similar results with nAG in early diagnosis of sleep respiratory events and identifying the level of airway obstruction. The time-saving dAG is of considerable referential importance in diagnosis of sleep respiratory events and analysing the level of airway obstruction.
Adult ; Airway Obstruction ; Exercise Test ; methods ; Female ; Humans ; Male ; Middle Aged ; Polysomnography ; methods ; Sleep ; Sleep Apnea, Obstructive ; diagnosis ; physiopathology

BACKGROUNDThe assessment of regional pulmonary ventilation and perfusion is essential for the evaluation of a variety of lung disorders. Pulmonary ventilation MRI using inhaled oxygen as a contrast medium can be obtained with a clinical MR scanner, without additional equipment, and has been demonstrated to be a feasible means of assessing ventilation in animal models and some clinical patients. However, few studies have reported on MR ventilation-perfusion imaging. In this study, we evaluated the usefulness of oxygen-enhanced ventilation in combination with first-pass Gd-DTPA-enhanced perfusion MRI in a canine model of pulmonary embolism and airway obstruction.

METHODSPeripheral pulmonary embolisms were produced in eight dogs by intravenous injection of gelfoam strips at the pulmonary segmental arterial level, and airway obstructions were created in five of the dogs by inserting a self-designed balloon catheter into a secondary bronchus. Oxygen-enhanced MR ventilation images were produced by subtracting images from before and after inhalation of pure oxygen. Pulmonary perfusion MR images were acquired with a dynamic three-dimensional fast gradient-echo sequence. MR ventilation and perfusion images were read and contrasted with results from general examinations of pathological anatomy, ventilation-perfusion scintigraphy, and pulmonary angiography.

RESULTSRegions identified as having airway obstructions matched using both MR ventilation and perfusion imaging, but regions of pulmonary embolisms were mismatched. The area of airway obstruction defects was smaller using MR ventilation imagery than that using ventilation scintigraphy. Abnormal perfusion regions due to pulmonary embolisms were divided into defective regions and reduced regions based on the time course of signal intensity changes. In the diagnosis of pulmonary embolisms with the technique of ventilation and perfusion MRI, sensitivity and specificity were 75.0% and 98.1%, respectively, and the diagnostic results of this MRI technique were in agreement with the results of ventilation-perfusion scintigraphy and pulmonary angiography (K: 0.899, 0.743).

CONCLUSIONSOxygen-enhanced ventilation in combination with pulmonary perfusion MRI can be used to diagnose abnormalities of airways and blood vessels in the lungs, and can provide regional functional information with high spatial and temporal resolution. This method possesses great potential value for clinical applications.

Airway Obstruction ; diagnosis ; physiopathology ; Animals ; Disease Models, Animal ; Dogs ; Gadolinium DTPA ; Magnetic Resonance Imaging ; Oxygen ; pharmacology ; Pulmonary Circulation ; Pulmonary Embolism ; diagnosis ; physiopathology ; Respiration

BACKGROUND: Several investigators have demonstrated a considerable disagreement between FEV1 and PEFR to assess the severity of airflow obstruction. The purpose of this study was to examine whether the discrepancy between the two measurements affects the assessment in the severity of acute asthma. METHODS: Thirty-five consecutive asthma patients measured both FEV1 and PEFR at 0, 1hr, 1, 3, 5, 7 days of an emergency room admission using a spirometer and a Ferraris PEFR meter. The degree of discrepancy between FEV1 and PEFR expressed as % predicted values was determined. RESULTS: When predictive equations that recommended by the instrument manufacturers were used, PEFR measured with the PEFR meter (f-PEFR) was significantly higher than FEV1 at all time points, with 16.1% mean difference and unacceptable wide limits of agreement (-20.0~52.3%). The classification in severity was significantly different between FEV1 and f-PEFR (p < 0.001). The discrepancy was inter-instrumental in large part because f-PEFR was 10.1% higher than spirometric PEFR. Different predictive equations altered the degree of the differences but could not completely correct it. CONCLUSION: These results indicate that f-PEFR values underestimate the severity of airflow obstruction in acute asthma despite using recommended predictive equations. Therefore, these confounding factors should be considered when the severity of airflow obstruction is assessed with PEFR.
Acute Disease ; Adult ; Aged ; Airway Obstruction/diagnosis/*physiopathology ; Asthma/*physiopathology ; Comparative Study ; Female ; Forced Expiratory Volume/physiology ; Human ; Male ; Middle Age ; Peak Expiratory Flow Rate/*physiology ; Predictive Value of Tests

OBJECTIVETo investigate the clinical characteristics and treatment of negative pressure pulmonary edema (NPPE) with upper airway obstruction (UAO) in children.

METHODData of 3 cases with NPPE and UAO in pediatric intensive care unit (PICU) from Mar, 2007 to May, 2013 were analyzed.

RESULT(1) Two cases were male and 1 was female with age respectively 6, 16 and 30 months.One had airway foreign body , 1 laryngitis , and 1 retropharyngeal abscess. The onset of NPPE varied from 5 to 40 minutes following relief of obstruction. (2) NPPE presented with acute respiratory distress with signs of tachypnea, tachycardia, 2 of the 3 with pink frothy pulmonary secretions, progressively decreased oxygen saturation, rales on chest auscultation and wheezing. (3) NPPE chest radiograph showed diffuse interstitial and alveolar infiltrates, images confirmed pulmonary edema. (4) All these patients received these therapeutic measures including mechanical ventilation, retaining high PEEP, diuretics, limiting the fluid input volume to 80-90 ml/ (kg×d) on the basis of circulation stability. The rales on chest auscultation disappeared after 10, 6, 12 hours. The ventilators of 2 patients were removed within 24 hours, in another case it was removed 50 hours later because of secondary infection. All patients were cured and discharged without complication.

CONCLUSIONNPPE progresses very fast, characterized by rapid onset of symptoms of respiratory distress after UAO, with pulmonary edema on chest radiograph. The symptoms resolve rapidly if early support of breath and diuretics are applied properly.

Acute Disease ; Airway Obstruction ; complications ; Child, Preschool ; Diuretics ; therapeutic use ; Female ; Foreign Bodies ; complications ; Humans ; Infant ; Laryngismus ; complications ; Male ; Positive-Pressure Respiration ; Postoperative Complications ; etiology ; physiopathology ; therapy ; Pulmonary Edema ; diagnosis ; etiology ; physiopathology ; therapy ; Radiography, Thoracic ; Retrospective Studies

PURPOSE: High-sensitivity assays enabled the identification of C-reactive protein (hs-CRP) at levels that were previously undetectable. We aimed to determine if hs-CRP could reflect airway inflammation in children, by comparing hs-CRP with spirometry and impulse oscillometry (IOS) parameters and symptomatic severities. MATERIALS AND METHODS: A total of 276 asthmatic children who visited Severance Children's Hospital from 2012-2014 were enrolled. Serum hs-CRP and pulmonary function tests were performed on the same day. Patients were divided into hs-CRP positive and negative groups (cut-off value, 3.0 mg/L). RESULTS: Of the 276 asthmatic children [median age 7.5 (5.9/10.1) years, 171 boys (62%)], 39 were hs-CRP positive and 237 were negative. Regarding spirometry parameters, we observed significant differences in maximum mid-expiratory flow, % predicted (FEF25-75) (p=0.010) between hs-CRP positive and negative groups, and a negative correlation between FEF25-75 and hs-CRP. There were significant differences in the reactance area (AX) (p=0.046), difference between resistance at 5 Hz and 20 Hz (R5-R20) (p=0.027), resistance at 5 Hz, % predicted (R5) (p=0.027), and reactance at 5 Hz, % predicted (X5) (p=0.041) between hs-CRP positive and negative groups. There were significant positive correlations between hs-CRP and R5 (r=0.163, p=0.008), and X5 (r=0.164, p=0.007). Spirometry and IOS parameters had more relevance in patients with higher blood neutrophil levels in comparison to hs-CRP. CONCLUSION: Hs-CRP showed significant correlation with FEF25-75, R5, and X5. It can reflect small airway obstruction in childhood asthma, and it is more prominent in neutrophil dominant inflammation.
Airway Obstruction/*diagnosis/etiology ; Asthma/*diagnosis/physiopathology ; C-Reactive Protein/*analysis ; Child ; Child, Preschool ; Female ; Forced Expiratory Volume ; Humans ; Inflammation/*etiology ; Male ; Neutrophils/metabolism ; Oscillometry/*methods ; Respiratory Function Tests/*methods ; Respiratory System ; Sensitivity and Specificity ; *Spirometry