Effects of terbutaline sulfate on pulmonary fluid transport in preterm rats / 临床儿科杂志

Objectives To investigate the effect and mechanism of terbutaline sulfate on pulmonary fluid transport in pre-mature rats. Methods Pregnant rats were randomly divided into 5 groups (control group, premature group, low-dose terbutaline group, high-dose terbutaline group and dexamethasone group). Drugs were administered by gavage after rats were fertilized for 16 days and continued for 3 days. Premature rats were taken out from the 19 days pregnant rats, and mature rats were delivered on the due day. Lungs were collected, and the ratio of pulmonary wet weight to dry weight (W/D), Na+, K+-ATP ase activity and concentration of cyclic adenosine monophosphate (cAMP) were measured in lungs. Results The W/D rate, Na+,K+-ATPase acti-vity and cAMP concentration in lungs had significant difference among different groups (P<0.01). The W/D rate was highest in premature group and lowest in the control group. It was lower in the high-dose terbutaline group than in the low-dose terbutaline group and the dexamethasone group (P<0.05). The Na+,K+-ATPase activity was lowest in premature group and highest in high-dose terbutaline group. It was higher in dexamethasone group, low-dose terbutaline group, and high-dose terbutaline group than in premature group, and it was higher in high-dsoe terbutaline group than in low-dose terbutaline group and dexamethasone group (P<0.05). The cAMP levle was lowest in premature group and highest in high-dose terbutaline group. It was higher in dexamethasone group, low-dose terbutaline group, high-dose terbutaline group than in premature group, and it was higher in high-dose terbutaline group than in low-dose terbutaline group and dexamethasone group (P<0.05). Conclusions Terbutaline sulfate facilitates lung fluid transport in premature rats, leading to reduce the W/D rate in terbutaline-treated group. We speculate that this effect is related to the increased cAMP level and Na+, K+-ATPase activity in lung tissue.

Effection of lung fluid clearance disturbance in late preterm infants with respiratory distress syndrome / 国际儿科学杂志

In recent studies,it has been demonstrated that the clinical efficacy of surfactant is poor for late protein infants.Besides,this kind of infants have not infection or other risk factors that may lead to respiratory distress syndrome(RDS).Thus,it is speculated that the pathogenesis of RDS of late preterm infants is different from preterm infants.New researches show that,as the key point of Lung fluid transport via Epithelium,α-ENaC plays an important role in the pathogenesis of RDS of late preterm infants through the inhibition of lung fluid clearance and activity of surfactant.This review highlights the most important mechanisms of Lung fluid absorption barrier in RDS of late preterm infants.

Positional Shifting of HRCT Findings in Patients with Pulmonary Edema

PURPOSE: To assess the value of positional shifting to a gravity-dependent area, as revealed by HRCT, in differ-entiating pulmonary edema (PE) from other conditions. MATERIALS AND METHODS: Sixteen consecutive patients in whom plain radiographs suggested the presence of pulmonary edema but the clinical findings were indefinite underwent HRCT of the lung. For initial scanning they were in the supine position, and then in the prone position. Findings of ground-glass opacity, interlobular septal thickening and peribronchovascular interstitial thickening were analyzed in terms of the presence and degree of shifting to a gravity-dependent area, a grade of high, intermediate or low being assigned. RESULTS: PE was diagnosed in 8 of 16 cases, the remainder being designated as non-pulmonary edema (NPE). Ground-glass opacity was observed in all 16, while the degree of positional shifting was found to be high in ten (PE:NPE=6:4), intermediate in four (PE:NPE=2:2), and low in two (PE:NPE=0:2). There was no significant difference between the two groups (p > 0.05). Interlobular septal thickening was observed in all but two NPE cases; the degree of shifting was high in six (PE:NPE=6:0), intermediate in one (PE), and low in seven (PE:NPE=1:6). Shifting was significantly more prominent in PE than in NPE cases (p<0.05). Peribronchovas-cular interstitial thickening was positive in all PE cases and one NPE case, with no positional shifting. CONCLUSION: Positional shifting of interlobular septal thickening to a gravity-dependent area, as demonstrated by HRCT, is the most specific indicator of pulmonary edema.

CT Findings of Pulmonary Edema: Comparison of Various Causes

PURPOSE: To assess the CT findings of pulmonary edema and to compare them, according to the cause. MATERIALS AND METHODS: CT findings (thin section, 20 ; thick section, 16) of pulmonary edema in 36 patients [cardiacdisease (group I, n=20), renal disease (group II, n=13), ARDS (group III, n=3)] were analyzed and compared. Therewere 21 men and 15 women ranging in age from 27 to 77 years. Distribution (even, central, or peripheral) andpatterns of pulmonary edema were compared between the three groups. RESULTS: The distribution of edema, appearingas consolidation or ground-glass opacity, was even in 75% (n=15) of group I, even in 46% (n=6) and central in 38%(n=5) of group II, and peripherally predominant in 100% (n=3) of group III. Interlobular septal thickening wasseen in 80% (n=16), 69% (n=9), and 0% of group I, II and III, respectively. Centrilobular ground-glass opacity wasnoted in six patients. CONCLUSION: In spite of various findings and considerable overlapping of the findings ofpulmonary edema, the distribution and pattern of edema differed according to the cause, and this can be helpfulfor differential diagnosis.

Pulmonary Edema: Radiographic Differential Diagnosis

PURPOSE: To evaluate the feasibility of using chest radiography to differentiate between three different etiologies of pulmonary edema. MATERIALS AND METHODS: Plain chest radiographs of 77 patients, who were clinically confirmed as having pulmonary edema, were retrospectively reviewed. The patients were classified into three groups: group 1(cardiogenic edema : n=35), group 2(renal pulmonary edema : n=16) and group 3(permeability edema :n=26). We analyzed the radiologic findings of air bronchogram, heart size, peribronchial cuffing, septal line, pleural effusion, vascular pedicle width, pulmonary blood flow distribution and distribution of pulmonary edema. In a search for radiologic findings which would help in the differentiation of these three etiologies, each finding was assessed. RESULTS: Cardiogenic and renal pulmonary edema showed overlapping radiologic findings, except for pulmonary blood flow distribution. In cardiogenic pulmonary edema(n=35), cardiomegaly(n=29), peribronchial cuffing(n=29), inverted pulmonary blood flow distribution(n=21) and basal distribution of edema(n=20) were common. In renal pulmonary edema(n=16), cardiomegaly(n=15), balanced blood flow distribution(n=12), and central(n=9) or basal distribution of edema(n=7) were common. Permeability edema(n=26) showed different findings. Air bronchogram(n=25), normal blood flow distribution(n=14) and peripheral distribution of edema(n=21) were frequent findings, while cardiomegaly(n=7), peribronchial cuffing(n=7) and septal line(n=5) were observed in only a few cases. CONCLUSION: On plain chest radiograph, permeability edema can be differentiated from cardiogenic or renal pulmonary edema. The radiographic findings which most reliably differentiated these two etiologies were air bronchogram, distribution of pulmonary edema, peribronchial cuffing and heart size. Only blood flow distribution was useful for radiographic differentiation of cardiogenic and renal edema.