Objective Comparing the influence on cardiac-pulmonary function of health and acute lung injury (ALI)dogs by proportional assist ventilation(PAV)and pressure support ventilation(PSV)modes.Methods Use intermittent positive pressure ventilation(IPPV)mode in health and ALI dogs,calculate elastance(Ers)and resistance(Rrs),then change to PAV,set the assist ratio 60%.Then change the mode into PSV,set the inspiratory pressure(IPAP)according to PAV,so that tidal volume(VT)and peak pressure(Ppeak)were the sanle as that of PSV respectively.Observe the changes of respiratory mechanics,blood gas analysis and hemodynamics during mechanical ventilation.Results For health dogs,compared with PAV,mean airway pressure(mPaw)and work of breath of ventilator(WOBv)of PSV was higher than those of PAV when VT were similar,the difference was remarkable;while the influence on hemodynamics was not different.For ALI dogs,compared with PAV,Ppeak,mPaw and pulmonary capillary wedge pressure(PCWP)of PSV was higher than those of PAV when VT were similar,the difference was remarkable.Conclusion For health and ALI dogs,compared with PSV,PAV has lower airway pressure and less influence on hemodynamies.

Objective To invest the prevalence and the missed diagnosis rate of COPD in presurgical patients and their relationship with high risk factors.Methods Epidemic study was carried out in presurgical patients who received pulmonary function test in PFT laboratory of Zhongshan Hospital.Totally 339 patients were selected and their general conditions,exposure history and PFT results were analyzed.Results The prevalence of COPD was 21.8%,and the missed diagnosis rate was 83.8%.About 53.1% subjects had positive exposure history,among which 43.1% had smoking history and 18.6% had occupational exposure history,with the prevalence of 34.2% and 36.5%,between which no statistical significance was revealed.The prevalence of COPD in subjects with negative exposure history was 8.8%,and the missed diagnosis rate was 71.4%.The prevalence of COPD with and without exposure history above the age of 50 years was 38.0% and 10.0%,the former being significantly higher.The prevalence of COPD of men was 25.1%,which was significantly higher than that of women(15.2%)(P=0.04).Logistic regression analysis showed that the prevalence had little relation with gender(OR=0.80,95% CI:0.42～1.51),but had relation with exposure history(OR=4.22,95% CI:2.35～8.34).The severity classification of 62 COPD patients who were newly diagnosed after this PFT:stage Ⅰ 30.6%,stage Ⅱ 56.5%,stage Ⅲ 11.3%,stage Ⅳ 1.9%.Conclusion Most presurgical patients have the risk factors of COPD,like smoking and occupational exposure,and the latter is especially higher in our country.The prevalence and the rate of missed diagnosis of COPD is very high and the classification of severity of most missed diagnosed patients is stage Ⅱ or even more severe.

Purpose　To explore the possibility and the effect of therapeutic bronchial asthma by antisense oligonucleotid.　Methods　Based on the IL-5 cDNA sequence of mouse,a segment of antisense oligonucleotid was designed and synthetized.5′-labeling of antisense oligonucleotid was signed by T4 PNK in order that the efficiency of stearylamine liposome in transfe-ting antisense oligonucleotid can be evaluated. Astham model was duplicated with ovalbumin (OVA) absorbed to aluminum hydroxide. T lymphocytes of mice were separated by nylon fiber method,then T lymphocytes transfected a different content of antisense oligonucleotid with stearylamine phys. positive liposome were cultured respectively in order to observe the effect of antisense oligonucleotid on IL-5 produced by T lymphocytes. IL-5 levels in the supernatants of T lymphocytes culture were determined by ELISA.　Results 　Stearylamine liposome could markedly increase the efficiency of antisense oligonucleotid transfection. The efficiency of antisense oligonucleotid transfection was the best at 1∶15 m/m(antisense oligonucleotid and SA liposome) and it was increased approximately 12 times.In healthy and asthma Balb/c mice, IL-5 was not detected in the supernatants of T lymphocytes culture without challenge with OVA.However,IL-5 was increased markedly in the supernatants of T lymphocytes culture challenged with OVA. After transfecting a different concentration antisense oligonucleotid, IL-5 levels in the supernatants of T lymphocytes culture were significantly lower than those in control cells without antisense oligonucleotid transfection. IL-5 levels decreased from (44.60±6.23) to (30.70±7.362),(17.20±6.181) and(8.16±2.34)pg/ml respectively. And IL-5 synthesis was inhibited by 31.17% , 61.43% and 81.7% respectively. 　Conclutions　IL-5 synthesis could be obviously inhibited by antisense oligonucleotid and showed a markedly relation between quantitative and effect. It is supported that the production of IL-5 be inhibited through preventing the transcription of IL-5 from T lymphocytes. The study provides foundation for antisense gene therapeutic asthma.

Objective To investigate the possible correlation of the clinical parameters, such as age, obesity, Epworth sleepiness score (ESS), with the severity of snoring and obstructive sleep apnea hypopnea syndrome (OSAHS). Methods One hundred and forty-eight patients with snoring during sleep admitted from May to Jul. 2008 were asked to answer the questions from a questionnaire concerning snoring, daytime sleepiness, and habits such as smoking and drinking, etc. All patients underwent at least a polysomnography (PSG) and the physical examination included height, weight, and body mass index (BMI). Age, BMI, the lowest SaO_2(%), ESS score, the biggest reduction of oxygen (%), a total suspension of time, the average correlation between respiratory disorder index (RDI) applied computing Pearson correlation test. Simple snoring and OSAHS group of mild, moderate and severe inter-group comparison analysis using generalized linear models. Results The prevalence of OSAHS was increased with age, higher in males than in females. A statistically significant correlation between ESS, BMI, the lowest SaO_2 with the RDI was detected. The difference of ESS, the lowest SaO_2 and the BMI was significant between the different serious patients (P<0.05). Conclusions OSAHS has a high morbidity rate in outpatients with snoring. Age and obesity are liability factors of OSAHS. BMI, the lowest SaO_2, ESS and RDI have well correlationship, which can be used to assess the pathogenetic condition, even make a primary diagnosis.

Objective To improve the understanding of the characteristics of obstructive sleep apnea-hypopnea syndrome (OSAHS) in the elderly patients, and to improve the diagnosis and treatment level. Methods Monitoring results of polysomnography (PSG) from 110 elderly OSAHS patients were analyzed retrospectively. The general conditions, sleep architecture, apnea and hypopnea events, oxygen reduction as well as possible correlations between various indicators were analyzed using SPSS18.0 statistical software. Results The median rapid eye movement (REM) and non-REM (NREM) sleep time of elderly patients with OSAHS accounted for 2. 17% and 76.73%,respectively. The median arousal index was 45.6 times/h. The longest time of sleep apnea was (51.94±22.06) s, the median of average sleep apnea time was 22.50 s, the longest time of hypopnea was (47.06±12.52) s and the average hypopnca time was (21.50±4.63) s. The median respiratory disturbance index (RDI) of all patients was 21.50, the patients with RDI between 5 and 20 accounted for 46.40%, with RDI between 20 and 40 accounted for 31.80% and with RDI over 40 accounted for 21.8%. The average oxygen saturation accounted for (93.45% ± 2.81%), the lowest oxygen saturation accounted for (76.3%± 10. 5%) and the median oxygen desaturation index was 31.6;times/h. BMI was negatively correlated with lowest oxygen saturation (r=-0. 378, P＜0.01) and average oxygen saturation ( r = - 0. 355, P ＜ 0. 01 ), while was positively correlated with oxygen desaturation index (r=0. 338, P＜0. 01 ). The lowest oxygen saturation was negatively correlated with the longest time of obstructive apnea (r= -0. 47, P＜0. 01 ), the average time of obstructive apnea (r=-0.316, P＜0.01), the longest time of hypopnea (r=-0.293, P＜0.01) and the average time of hypopnea (r=-0. 277, P＜0.01). The median time intervals of oxygen desaturation during supine, left side and right side position were 2.36 min, 11.54 min and 12.45 min,respectively. The median time intervals of oxygen desaturation during left side and right side position were both longer than that of supine position (Z= -6.12 and -7. 10 respectively, both P＜0.01).Conclusions Elderly patients with OSAHS manifest obvious disorder of sleep structural and sleep fragmentation. According to RDI, the majority of the patients are classified as mild to moderate in severity. However, elderly patients with OSAHS are severe regarding to hypoxia relatively. The severity of hypoxia is related with BMI and the lasting time of sleep-disordered breathing events, and hypoxia are less severe when sleeping on left side or on right side.

OBJECTIVETo compare the influence of cardiac-pulmonary function on clinical acute respiratory failure patients using Proportional assist ventilation (PAV), Pressure support ventilation (PSV) and intermittent positive pressure ventilation (IPPV). Here, we also describe some our experience with the clinical use of PAV.

METHODSUsing the IPPV mode in ten acute respiratory failure patients, calculate Elastance (Ers) and Resistance (Rrs), then change to PSV, set inspiratory positive airway pressure (IPAP) according to IPPV, so that tidal volume (V(T)) is the same as that of IPPV. We then changed the mode into PAV and set the assist ratio according to PSV, so that V(T) and Ppeak were the same as that of PSV. Then we observed the changes of respiratory mechanics, blood gas levels and hemodynamics during ventilation.

RESULTSCompared with PSV and IPPV, peak pressure (Ppeak) of PAV was markedly lower while V(T) was similar; work of breathing of patient (WOBp), and work of breathing of ventilation (WOBv) were also lower; center vein pressure (CVP) and pulmonary capillary wedge pressure (PCWP) of PAV were markedly lower than that of IPPV while V(T) were similar. Compared with PSV, V(T), mean blood pressure (mBP) and cardiac output (CO) of PAV were higher. Mean pulmonary artery pressure (mPAP) and WOBp of PAV were lower while Ppeak was similar; the differences in WOBp were notable.

CONCLUSIONSFor clinical acute respiratory failure patients, compared with PSV and IPPV, PAV has lower airway pressure, less WOBp and less influence on hemodynamics.

Acute Disease ; Adult ; Aged ; Aged, 80 and over ; Cardiac Output ; physiology ; Female ; Hemodynamics ; physiology ; Humans ; Male ; Middle Aged ; Pulmonary Ventilation ; physiology ; Pulmonary Wedge Pressure ; physiology ; Respiration, Artificial ; methods ; Respiratory Insufficiency ; physiopathology ; therapy ; Ventilators, Mechanical