肺减容术治疗晚期肺气肿

目的 总结肺减容术治疗晚期肺气肿的临床经验。方法 回顾性分析22例晚期肺气肿行肺减容术患者的临床资料。结果 患者术前1s用力呼吸量（FEV1）为24．5％、残气量（RV）为196．5％、总肺活量（TLC）为130．5％,术后FEV1为27．8％、RV为148．8％,TLC为112．5％。术前16例患者经常吸氧,术后5例活动后需吸氧。术前16例完成6min行走试验,平均行走198m,术后所有患者均完成行走试验,平均行走256m。术前呼吸困难14例3级,8例4级;术后5例2级,13例3级,4例4级。结论 靶区明确的非均质型尤其泡性肺气肿是肺减容术最佳适应证,经严格选择均质型肺气肿病例亦可手术。手术适应证及禁忌证值得进一步探讨;胸腔镜辅助腋下小切口单侧肺减容术安全、可靠、有效;机械缝切器和牛心包加垫可减少漏气。     

Measurement of heterogeneous distribution on Technegas SPECT images by three-dimensional fractal analysis

This review article describes a method for quantifying heterogeneous distribution on Technegas (99mTc-carbon particle radioaerosol) SPECT images by three-dimensional fractal analysis (3D-FA). Technegas SPECT was performed to quantify the severity of pulmonary emphysema. We delineated the SPECT images by using five cut-offs (15, 20, 25, 30 and 35% of the maximal voxel radioactivity), and measured the total number of voxels in the areas surrounded by the contours obtained with each cut-off level. We calculated fractal dimensions from the relationship between the total number of voxels and the cut-off levels transformed into natural logarithms. The fractal dimension derived from 3D-FA is the relative and objective measurement, which can assess the heterogeneous distribution on Technegas SPECT images. The fractal dimension strongly correlate pulmonary function in patients with emphysema and well documented the overall and regional severity of emphysema.     

Anaesthetic management of a 6-week-old child with unilateral pulmonary interstitial emphysema

We report the case of a 6-week-old female infant suffering from respiratory distress related to cystic changes affecting the entire left lung. Anaesthesia was induced with sevoflurane in oxygen and spontaneous ventilation was maintained until intubation of the right main bronchus was secured. A left pneumonectomy was performed and the postoperative course was uneventful. The pathological diagnosis was pulmonary interstitial emphysema. This has not been previously reported in an otherwise normal child delivered uneventfully at term. The anaesthetic management of a child with a cystic lung lesion is discussed.     

血管内皮生长因子干预烟熏大鼠肺气肿的实验研究

目的:探讨血管内皮生长因子(VEGF)对烟熏大鼠肺气肿病变的修复作用。方法:Wistar大鼠24只,随机分为VEGF组、对照组和健康对照组。VEGF组、对照组用烟熏气管内滴入猪胰弹性蛋白酶制作肺气肿模型,健康对照组气管内滴入生理盐水作为对照,3个月后模型成功。VEGF组大鼠气管内滴入VEGF,对照组和健康对照组滴入生理盐水,每周1次,共3次。4周后测大鼠体重,肺泡形态学变化。结果:VEGF组与对照组相比平均肺泡数明显增加(P<0.05)、平均肺泡间隔和平均肺泡面积减小(P<0.05)。结论:VEGF在一定程度上可以修复肺气肿病变。     

均质性肺气肿经支气管镜单向活瓣肺减容术研究

目的探索经支气管镜单向活瓣肺减容术对均质性肺气肿的治疗效果。方法均质性肺气肿Beagle犬7只,在动物右肺经支气管镜置入2～4枚支气管单向活瓣,2个月后处死实验动物,进行大体标本观察,光镜病理学评价及电子计算机图像定量分析,并与基本情况相似的正常犬和肺气肿模型犬进行比较,评价疗效。结果共置入21枚活瓣,除2枚活瓣咳出外,余19枚活瓣均未移位。实验动物无明显不良反应。观察大体标本发现单向活瓣阻塞的肺叶缩小、质地较硬,脏层胸膜有局灶瘢痕形成,支气管壁周围有少许组织增生;周围肺叶无出血、实变。病理学观察及图像分析结果示7只实验犬被阻塞的肺叶均有中度肺泡炎及肺间质纤维化表现。图像定量分析结果显示,与肺气肿模型犬比较,7只实验犬有明显肺泡陷闭、肺容积缩小表现（P〈0.01）,与正常犬比较也有肺泡陷闭、肺容积缩小表现（P〈0.05）。结论单向活瓣肺减容术对均质性肺气肿犬的治疗在一定程度上是有效的。     

High-dose versus low-dose bovine surfactant treatment in very premature infants

The aim of the study was to determine if high-dose bovine surfactant (Alveofact, initially 100 mg/kg birth weight) would improve oxygenation compared with low-dose surfactant (50 mg/kg birth weight) administered intratracheally within 1 h after birth. Inclusion criteria included gestational age 24–29 weeks and birth weight 500–1500 g, intubation and mechanical ventilation, absence of congenital malformations and bacterial infections. Retreatment was considered if the fraction of inspired oxygen (FiO₂) was > 0.4 (dose 50 mg/kg birth weight). The primary endpoint was level of oxygenation (PaO₂/ FiO₂) 2 h after treatment. The study design was a sequential analysis using a triangular test with alpha = 0.05 and 95% power to detect a 25 % improvement in the endpoint. Oxygenation was improved significantly with high-dose ( n = 42) compared to low-dose treatment ( n =48): 30.9±15.0 kPa (231.5±112.7 mmHg) versus 24.1±15.7 kPa (180.6±118.0 mmHg) (mean ± SD). The survival rate was 83% in both groups and the incidence of pulmonary interstitial emphysema was 33% versus 14% with the high-dose treatment. We conclude that high-dose surfactant significantly improved oxygenation and reduced lung barotrauma. An initial dose greater than 50 mg/kg birth weight of surfactant is required for optimal acute response.     

Outcome of congenital lung abnormalities detected antenatally

To determine the outcome of congenital lung abnormalities, data were collected retrospectively between January 1991 and December 1996 on any foetus found to have a lung lesion on antenatal ultrasound. A total of 23 foetuses had lung lesions on antenatal ultrasound. In two foetuses the antenatal ultrasound showed bilateral enlarged "bright" echogenic lungs with evidence of hydrops. Both pregnancies were terminated and tracheal atresia was confirmed. In 15 foetuses the antenatal ultrasound appearance was of a unilateral "bright" echogenic lung. There was one case of bronchial atresia and two cases of congenital lobar emphysema, which all had surgery. In nine cases there was a reduction in the size of the lesion on serial antenatal ultrasounds and no lesion was detected after birth. In three cases a small lesion was present after birth on chest radiography. In six foetuses the antenatal ultrasound appearance was of unilateral cystic or mixed cystic and echogenic lung lesions. Two pregnancies were terminated; both had congenital cystic adenomatoid malformation. Four pregnancies were continued and three infants had surgery soon after birth and were confirmed to have had congenital cystic adenomatoid malformation. One infant has been managed conservatively. In conclusion, a definitive diagnosis cannot usually be made antenatally. A large lesion on initial scan does not necessarily predict a poor outcome. The natural history of small asymptomatic postnatal lesions is unknown and a long-term prospective study is needed to determine the outcome of these lesions.     

Respiratory outcomes among South African coal miners at autopsy

BACKGROUND: Studies of dose-response relationships between respiratory outcomes at autopsy and coal dust exposure are limited. The Pathology Automation System (PATHAUT) database of South African miners, is one of the largest autopsy databases of occupational lung disease. This study described the prevalence of respiratory outcomes among South African coal miners at autopsy, and determined whether dose response relationships existed between emphysema and exposure. METHODS: Autopsies conducted from 1975 to 1997 on coal miners with exclusive coal mining exposure and having exposure duration information (n = 3,167) were analyzed from PATHAUT. Logistic regression was used to determine relationships between exposure and outcomes, controlling for race, smoking and age on a subset for whom smoking history was available (n = 725). RESULTS: The mean duration of exposure was 11.0 years. Most were black miners (75.3%) with significant differences in the mean ages of black and white miners (37.9 and 55.3 years, respectively). Only 22.9% of cases had information on smoking. The prevalence of silicosis, tuberculosis (TB), coal workers' pneumoconiosis (CWP), and moderate and marked emphysema were 10.7%, 5.2%, 7.3%, and 6.4%, respectively. All diseases, except TB, were associated with exposure duration. Black miners had 8.3 and 1.2 fold greater risks for TB and CWP, respectively, than white miners. White miners had an increased risk of 1.4 and 5.4 for silicosis and moderate to marked emphysema, respectively. In models unadjusted for age, and including smoking, moderate to marked emphysema was strongly associated with exposure duration (OR = 3.4; 95% CI = 1.9-5.9 for highest tercile of exposure duration). Exposure-related risk estimates were reduced when age was introduced into the model. However, age and duration of exposure were highly correlated, (r = 0.68) suggesting a dilution of the exposure effect by age. CONCLUSIONS: There were significant dose related associations of disease, including emphysema, with coal dust exposure.     

COPD: a prevalence estimation model

OBJECTIVES: COPD is increasingly recognized as a leading cause of global morbidity and mortality. Prevalence estimates for COPD are generally unavailable or unreliable. Thus, a simple and valid model for estimating COPD prevalence would provide essential information for policymakers in addressing a major burden of worldwide illness. METHODOLOGY: We modelled the relationships among readily available demographic data (e.g. age, gender), smoking prevalence, and COPD prevalence based on a literature review. We also included risks of COPD from environmental pollution and associations with socioeconomic status. RESULTS: The model specifies a minimum of eight input variables to predict COPD prevalence in a given population: population by age, gender, smoking prevalence, prevalence of COPD among smokers, proportion living in rural areas, country by level of development, and exposures to environmental pollution. Actual COPD prevalence data from large population-based studies in Spain, Norway, Poland and Nepal compared favourably with the model projections (P > or = 0.10). CONCLUSION: The model is a simple tool for estimating the prevalence of COPD populations in a given region or country. Further studies are needed to prospectively validate the model and test the assumptions upon which it is based.     

Bilateral congenital lobar emphysema: how should we proceed?

We report a case of a 4-week-old male infant who presented with increasing respiratory distress and was diagnosed to have bilateral congenital lobar emphysema on chest x-ray. Our approach to the surgical management in two sequential operations of left upper lobectomy followed by right middle lobectomy is discussed.