Influenza A Strain-Dependent Pathogenesis in Fatal H1N1 and H5N1 Subtype Infections of Mice

To determine if fatal infections caused by different highly virulent influenza A viruses share the same pathogenesis, we compared 2 different influenza A virus subtypes, H1N1 and H5N1. The subtypes, which had shown no pathogenicity in laboratory mice, were forced to evolve by serial passaging. Although both adapted viruses evoked diffuse alveolar damage and showed a similar 50% mouse lethal dose and the same peak lung concentration, each had a distinct pathologic signature and caused a different course of acute respiratory distress syndrome. In the absence of any virus labeling, a histologist could readily distinguish infections caused by these 2 viruses. The different histologic features described in this study here refute the hypothesis of a single, universal cytokine storm underlying all fatal influenza diseases. Research is thus crucially needed to identify sets of virulence markers and to examine whether treatment should be tailored to the influenza virus pathotype.     

重度硫酸二甲酯中毒的抢救护理

近二年 ,该院收住了7例硫酸二甲酯中毒患者 ,其中 ,重度中毒者3例。救治中体会到:严密监护、及时气管切开、及早应用呼吸机、有效气道管理是抢救成功的关键 ;同时还必须做好心理护理、营养支持、预防感染及眼的保护等 ,以提高出院后的生活质量     

血液滤过对严重创伤后并发急性呼吸窘迫综合征患者氧合功能和血流动力学的影响

目的 研究血液滤过对严重创伤后并发ARDS患者氧合功能和血流动力学的影响。方法 选择严重创伤后ARDS患者12例，在呼吸机辅助或控制呼吸下行血液滤过治疗，于血液滤过后1－5d内用Swan-Ganz漂浮导管监测血流动力学和肺氧功能的变化。结果 与血液滤过前比较，滤过后第1天CVP、MPAP、SVRI、PVRI显著降低，整个血液滤过时间PaO2／FiO2升高非常显著，MAP、PCWP、HR、CI、DO2、VO2、ExtrO2、Qs/Qt无显著变化。结论 血液滤过对严重创伤后ARDS患者的血流动力学和氧合功能无明显影响，但可使氧合指数升高。     

Time-course and dose-response of nitric oxide inhalation for systemic oxygenation and pulmonary hypertension in patients with adult respiratory distress syndrome

Abstract. Inhalation of nitric oxide (NO), an endoge-neous vasodilator, was recently described to reduce pulmonary vascular resistance, and to improve arterial oxygenation by selective vasodilation of ventilated areas in patients with adult respiratory distress syndrome (ARDS). We describe the time-course and dose-response of initial short-term NO inhalation in 12 patients with ARDS. Enhanced oxygenation was achieved within 1–2 min after starting NO inhalation; after inhalation, baseline conditions were re-achieved within 5–8 min. Effective doses for improvement of oxygenation [baseline: P_aO₂= 10.2±2.5 KPa (76.4±18.7 mmHg)] were low: ED₅₀ was about 100 ppb—a concentration similar to the atmosphere. NO doses of more than 10 ppm [10 ppm NO: P_aO₂=17.3 ± 3.3 KPa (129.4 ± 25.1 mmHg)] re-worsen the arterial oxygenation. The ED₅₀ for reduction of mean pulmonary artery pressure was 2–3 ppm. This indicates that inhalation of NO for improvement of oxygenation in severe ARDS should be performed using lower doses, with lower risk of toxic side effects.     

乌司他丁在急性呼吸窘迫综合征的临床应用研究

目的观察乌司他丁对急性呼吸窘迫综合征(ARDS)的临床作用。方法选择56例ICU收治的ARDS患者作为研究对象,采用随机双盲的方法分为乌司他丁治疗组(A组)和糖皮质激素治疗组(B组)两组,分别静脉推注乌司他丁60万U/d和甲基强的松龙120 mg/h,观察用药后1 h患者收缩压、尿量、心率、氧合指数的改变以及1周后胃液pH值和潜血试验、血糖的变化,比较两组患者真菌感染发生率、带管时间、平均住院时间和死亡率的变化。结果与治疗前相比,用药后1 hA、B两组收缩压升高(18.6±4.3)mm Hg和(16.7±5.1)mm Hg,尿量增加(35.5±9.5)mL和(37.5±8.7)mL,心率下降(21.4±7.3)次/m in和(19.8±6.9)次/m in,氧合指数增加(23.6±11.2)mm Hg和(20.9±10.6)mm Hg;1周后A、B两组胃液pH值分别下降0.03±0.01和0.08±0.02,潜血试验阳性率分别为14.86%和32.14%,血糖升高(1.42±0.09)μmol/L和(5.73±0.13)μmol/L,真菌感染发生率分别为21.43%和67.86%,带管时间、平均住院时间和死亡率分别为36.5 d和53.4d、52.7 d和72.6 d、28.57%和42.86%。结论乌司他丁具有抗休克、改善循环、改善氧合、降低平均住院时间和死亡率的作用,而静注乌司他丁后应激性溃疡、高血糖和真菌感染发生率均较低,可望代替糖皮质激素应用于ARDS的临床救治。     

急性呼吸窘迫综合征的影像学表现

急性呼吸窘迫综合征(acute respiratory distress,ARDS)是指由心源性以外的各种肺内、外致病因素所导致的急性、进行性缺氧性呼吸衰竭,肺内、外致病因素分别引起肺源性和肺外源性ARDS,其特征性病理表现为肺泡内液体渗出和透明膜形成,导致广泛肺泡实变。本病初期的胸片检查可见边界模糊的磨玻璃影,随病情进展则出现弥漫性、密度均匀的大片实变影;CT扫描可显示病变从头向足以及从腹向背两个方向上形成的密度递增征象,仰卧位时,腹侧肺野透亮度接近正常,而实变影位于背侧脊柱两旁,中间区域则呈现磨玻璃样改变。     

急性肺损伤/急性呼吸窘迫综合征患者预后因素分析

目的 研究影响急性损伤/急性呼吸窘迫综合征(acute lung injury/acute respiratory distress syndrome,ALI/ARDS)患者的预后因素.方法 回顾分析巾国医学科学院肿瘤医院ICU 2005年1月至2006年12月问全部63例AIJ/ARDS患者的资料.根据病情转归分为生存组(n:39)和死亡组(n=24).根据病凶分为肺外型和肺内型.结果 ALI/ARDS发病率为5.2%(63/1201).单因素分析发现生存组和死亡组之间机械通气时间(P=0.028)、血肌酐水平(P=0.031)、氧合指数(P=0.023)、转入时APACHE Ⅱ评分(P<0.001)和转入时SOFA评分(P<0.001)差异具有统计学意义.多因素分析发现仅转入时APACHEⅡ评分影响预后(P=0.015,OR:3.809,95%CI:1.295～11.203).肺内型和肺外型两组之间1年生存率差异无统计学意义(63.9%vs.55.4%,P=0.982).ARDS组和ALI组两组之间1年生存率差异具有统计学意义(44.9%vs.88.9%,P=0.008).结论 转入时患者APACHE Ⅱ评分是判断ALI/ARDS患者预后的独立危险因素,ALI/ARDS的病因不影响ALI/ARDS患者的生存.     

Combining partial liquid ventilation with nitric oxide to improve gas exchange in acute lung injury

Objective: To assess the effects of increasing concentrations of inhaled nitric oxide (NO) during incremental dosages of partial liquid ventilation (PLV) on gas exchange, hemodynamics, and oxygen transport in pigs with induced acute lung injury (ALI). Design: Prospective experimental study. Setting: Experimental intensive care unit of a university. Subjects: 6 pigs with induced ALI. Interventions: Animals were surfactant-depleted by lung lavage to a partial pressure of oxygen in arterial blood (PaO₂) < 100 mmHg. They then received four incremental doses of 5 ml/kg perflubron (LiquiVent). Between each dose the animals received 0, 10, 20, 30, 40, and 0 parts per million (ppm) NO. Measurements and main results: Blood gases, hemodynamic parameters, and oxygen delivery were measured after each dose of perflubron as well as after each NO concentration. Perflubron resulted in a dose-dependent increase in PaO₂. At each perflubron dose, additional NO inhalation resulted in a further significant (ANOVA, p < 0.05) increase in PaO₂, with a maximum effect at 30 ± 10 ppm NO. The 5 ml/kg perflubron dose led to a significant decrease in mean pulmonary artery pressure, which decreased further with higher NO concentrations. Conclusions: PLV can be combined with NO administration and results in a cumulative effect on arterial oxygenation and to a decrease in pulmonary artery pressure, without having any deleterious effect on measured systemic hemodynamic parameters. Received: 29 April 1996 Accepted: 24 October 1996     

Bronchoalveolar lavage fluid characteristics of early intermediate and late phases of ARDS

Objective: To determine the concentration of proteins and phospholipids, markers of inflammatory reaction such as platelet-activating factor (PAF), and cell alterations in bronchoalveolar lavage (BAL) fluid during the evolution of the acute respiratory distress syndrome (ARDS). Design: Prospective controlled study. Setting: 14-bed medical-surgical intensive care unit in a 750-bed university teaching hospital. Patients: 19 mechanically ventilated patients, 9 patients with ARDS and 10 patients without cardiopulmonary disease (controls), were eligible for this study. Interventions: BAL was performed during the early, intermediate, and late phases of ARDS. Measurements and results: Total phospholipids and individual phospholipid classes of the surfactant, proteins, PAF, and cells were measured. High levels of PAF, an increase in neutrophils and proteins, and quantitative as well as qualitative alterations in phospholipids in BAL fluid were observed in ARDS patients compared to the control group. PAF, proteins, and neutrophils were higher in early ARDS than in intermediate or late ARDS. The surfactant pool increased in the early phase and decreased in the intermediate or late phase of the syndrome. The qualitative alterations of surfactant consist of reduced phospholipid content in the surfactant structures with good surface properties; moreover, there was a considerable decrease in the percentage of phosphatidylcholine and phosphatidylglycerol, followed by an increase in phosphatidylethanolamine, phosphatidylserine, phosphatidylinositol, and sphingomyelin in all three phases of ARDS compared to the control group. Lyso-phosphatidylcholine was detectable only in late ARDS. Conclusion: Total surfactant phospholipids, surfactant components, and inflammatory markers such as PAF, cells, and proteins were affected in patients with ARDS. These factors, undergoing quantitative alterations during the course of ARDS, could have a significant role in the pathogenesis and evolution of ARDS. Received: 8 July 1997 Accepted: 17 December 1997     

Lowering pulmonary artery pressure in a patient with severe acute respiratory failure

A case of pulmonary arterial hypertension on the basis of ARDS is presented. The cyclooxygenase inhibitor Ibuprofen is used to lower pulmonary arterial pressure, resulting in an improvement in the right ventricular function.