Sequential non-invasive mechanical ventilation following short-term invasive mechanical ventilation in COPD induced hypercapnic respiratory failure / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To estimate the feasibility and the efficacy of early extubation and sequential non-invasive mechanical ventilation (MV) in chronic obstructive pulmonary disease (COPD) with exacerbated hypercapnic respiratory failure.</p><p><b>METHODS</b>Twenty-two intubated COPD patients with severe hypercapnic respiratory failure due to pulmonary infection (pneumonia or purulent bronchitis) were involved in the study. At the time of pulmonary infection control window (PIC window) appeared, when pulmonary infection had been significantly controlled (resolution of fever and decrease in purulent sputum, radiographic infiltrations, and leukocytosis) after the antibiotic and the comprehensive therapy, the early extubation was conducted and followed by non-invasive MV via facial mask immediately in 11 cases (study group). Other 11 COPD cases with similar clinical characteristics who continuously received invasive MV after PIC window were recruited as control group.</p><p><b>RESULTS</b>All patients had similar clinical characteristics and gas exchange before treatment, as well as the initiating time and all indices at the time of the PIC window. For study group and control group, the duration of invasive MV was (7.1 +/- 2.9) vs (23.0 +/- 14.0) days, respectively, P < 0.01. The total duration of ventilatory support was (13 +/- 7) vs (23 +/- 14) days, respectively, P < 0.05. The incidence of ventilator associated pneumonia (VAP) were 0/11 vs 6/11, respectively, P < 0.01. The duration of intensive care unit (ICU) stay was (13 +/- 7) vs (26 +/- 14) days, respectively, P < 0.05.</p><p><b>CONCLUSIONS</b>In COPD patients requiring intubation and MV for pulmonary infection and hypercapnic respiratory failure, early extubation followed by non-invasive MV initiated at the point of PIC window significantly decreases the invasive and total durations of ventilatory support, the risk of VAP, and the duration of ICU stay.</p>

Beta-carotene protects rats against bronchitis induced by cigarette smoking / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the protective effects of beta-carotene in rats against the development of chronic bronchitis induced by cigarette smoking.</p><p><b>METHODS</b>Forty-two Male Wistar rats were randomly divided into three study groups: (1) control (n = 15), animals underwent no treatment; (2) cigarette smoking (n = 15), animals developed chronic bronchitis through long-term cigarette smoking twice a day for 75 d; (3) beta-carotene plus cigarette smoking animals (n = 12) were given 1 ml or 15 mg/kg beta-carotene orally every day just before cigarette smoking. The levels of IL-6, IL-8, NO, superoxide dismutase (SOD) and lipoperoxide (LPO) in serum, bronchoalveolar lavage fluid (BALF) and lung tissue were measured and the pathological changes to lung tissue were analyzed using light microscopy.</p><p><b>RESULTS</b>Long-term cigarette smoking caused an obvious increase in the amount of IL-6, IL-8 and LPO and a sharp decrease in the levels of NO and SOD in smoking animals compared to controls. beta-carotene intake reversed all the changes induced by smoking and alleviated the pathological changes caused by chronic bronchitis.</p><p><b>CONCLUSIONS</b>Quantitative oral intake of beta-carotene had protective effects against chronic bronchitis induced by long-term cigarette smoking, which was associated with the increased production of NO, the clearance of some oxidative free radicals (OFR) and the alleviation of chronic inflammation.</p>

Proportional assist ventilation: methodology and therapeutics on COPD patients compared with pressure support ventilation / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the impact of proportional assist ventilation (PAV) on tolerance and breathlessness in ventilated chronic obstructive pulmonary disease (COPD), and to describe the patient-ventilator interaction, hemodynamic state, breathing pattern and work of breath during PAV and pressure support ventilation (PSV).</p><p><b>METHODS</b>Ten intubated COPD patients on weaning from mechanical ventilation were studied. Elastance and resistance were measured by both the inspiratory-hold technique during a brief period of volume control ventilation and runaway technique during PAV. Each assistance level of PAV (80%, 60% and 40%) and PSV was selected randomly. Patients' response, hemodynamics, blood gas and lung mechanics were monitored.</p><p><b>RESULTS</b>Tidal volume and respiratory rate didn't change in a consistent manner as the level of assist was decreased (P > 0.05). With the level of assist increasing, peak inspiratory pressure was increasing significantly (P < 0.05), while patients' work of breath had the tendency to decrease (P < 0.05). A significant difference in the Borg Category Scale was observed between PAV and PSV (0.50 [1.50] vs. 0.75 [2.00], P < 0.05) at the same degree of respiratory muscle unloading. PaCO(2) was significantly higher on PAV (54 [23] mm Hg) than on PSV (48 [23] mm Hg) (P < 0.05). Peak inspiratory pressure on PAV was significantly lower than on PSV (16 +/- 4 cm H(2)O vs. 21 +/- 3 cm H(2)O, respectively, P < 0.05). Hemodynamics and oxygenation remained unchanged.</p><p><b>CONCLUSIONS</b>PAV is a feasible method for supporting ventilator-dependent patients and was well tolerated. It can improve the breathing pattern and reduce inspiratory effort. At the same degree of respiratory muscle unloading, PAV can be implemented at much lower peak inspiratory pressure than PSV. It can also apply proportional pressure support according to the patients' ventilatory demand.</p>

Protective effect of ambroxol against the lung damage in chronically hypoxic rats / 中国病理生理杂志

AIM: To investigate the effect of ambroxol on pulmonary and vascular injury in chronically hypoxic rats. METHODS: 36 male Wistar rats were randomly divided into 3 groups: normal control,chronically intermittent hypoxia(CIH) and ambroxol precaution group(AP).The CIH and AP groups were made into the chronically hypoxic models .The mean pulmonary artery pressure(PAPM) and the levels of plasma superoxide dismutase (SOD) and plasma nitric oxide (NO),lipid peroxide(LPO) were determined. The levels of the lung homogenates SOD, LPO, NO and the changes in pulmonary vascular structure were also examined. RESULTS: The levels of plasma and lung homogenates SOD,NO in CIH group were respectively significantly lower than that of normal control and AP group ( P

Experimental study on setting up hypercapnic model and its pathophysiological changes in rats / 中国病理生理杂志

AIM: To reproduce hypercapnic models and approach some pathophysiological changes in rats. METHODS: The mixed gases of high concentrated carbon dioxide (8% CO 2, 21% O 2, 71% N 2) were given to wistar rats 7 hours a day for 28 days. The various indexes were compared between control group (group A) and hypercapnic group (group B). RESULTS: The PaCO 2 [(55.90?4.34) mmHg] and the lipid peroxides (LPO) contents in plasma, lung tissue and right ventricle were significantly higher in group B than those in group A ( P