The child with recurrent respiratory infections: normal or not?

Respiratory infections (RI) are one of the major complaints in children and adolescents, and represent a demanding challenge for the pediatrician. It has been estimated that at least 6% of Italian children younger than 6 yr of age present recurrent respiratory infections (RRI). Children with RRI are not affected by severe alterations of the immune system. RRI represent essentially the consequence of an increased exposure to infectious agents during the first years of life, when immune functions are still largely immature. Several social and environmental factors, such as day-care attendance, family size, air pollution, parental smoking, and home dampness, represent important risk factors for airway diseases and may contribute in various degrees to determine the incidence of RRI. The main problem for the pediatrician is to discriminate normal children with high RI frequency related to an augmented exposure to environmental risk factors from children affected by other underlying pathological conditions (immunological or not), predisposing to infectious diseases. When RRI diagnosis has been formulated, removal of environmental risk factors (i.e. precocious day-care attendance, smoking in the household) must first be suggested.     

小儿急性肺损伤的短期肺功能随访

Objective To study the pulmonary functions of pediatric ALI/ARDS(acute lung injury/acute respiratory distress syndrome) survivors. Method A prospective cohort study of all survivors of ALI/ARDS in the PICU of Beijing Children's Hospital was performed. Patients were divided into three groups(0-3 years of age,3 ～ 7 years of age, and over 7 years of age) and followed up three months after diagnosis. Results There were 36 survivors in total of 44 ALl patients, three patients lost follow-up, 12 died and 21 survived. Five survivors refused to participate in the study because of asymptomatic, and one was unable to participate because of lymphoma com-bined with sepsis. A total of 15 children completed the whole survey (11 patients were less than 3 years old, andfour were over 7 years of age). Twelve patients had no discomfort in their respiratory tracts. Three months after be-ing enrolled, the pulmonary functions of all children improved, especially in terms of tidal volume and respiratory compliance (P<0.05). Conclusions The abnormal respiratory symptoms and signs in most children disap-peared three months after discharge. Most survivors still have pulmonary dysfunction at 3 monthes after discharge, but better than discharge.     

Heart rate response to breathing: dependency upon breathing pattern

Summary. Heart rate responses to stepwise and periodic changes in lung volume were studied in seven young healthy males. Stepwise inspiration and expiration both resulted in an increase in heart rate followed by a rapid decrease in heart rate. The fastest heart rate was reached in 1·6 ± 0·5 s and in 3·6 ± 1·4 s in response to inspiration and expiration, respectively (P < 0·01). The slowest heart rate was reached in 4·8± 1·0 s and in 7·6± 1·9 s in response to inspiration and expiration, respectively (P < 0·01). Following this biphasic change the heart rate returned to a steady level. The difference between the fastest and the slowest heart rates was significantly larger in response to inspiration (21·7 ± 7·3 beats per minute) than in response to expiration (12·0±7·3 beats per minute; P < 0·01). Periodic changes in lung volume were performed with frequencies from 3·0 to 12·0 respirations per minute (r.p.m.). The changes in heart rate showed a constant amplitude in the frequency range below 5·5 r.p.m. Maximal heart rate changes were found at frequencies of 5·5 to 7·0 r.p.m. Changes in heart rate decreased in a linear manner on a log-log scale in the frequency range above 7·0 r.p.m. The relation between frequency and changes in heart rate is explained by interference between the transient changes in heart rate induced both by inspiration and by expiration. It is concluded that if heart rate changes in response to periodic changes in lung volume are to be used as a measure of vagal function a number of factors have to be taken into consideration and to simplify the analysis of heart rate responses to breathing we recommend, instead, the use of the transient changes in heart rate induced by stepwise changes in lung volume.     

加替沙星序贯治疗下呼吸道细菌感染的药物经济学评价

目的对加替沙星序贯治疗下呼吸道细菌感染进行药物经济学评价。方法将69例下呼吸道细菌性感染患者，随机分为A组（34例）、B组（35例），其中A组采用加替沙星注射液400mg静脉滴注，每天1次，连用10天；B组先用加替沙星注射液400mg静脉滴注，每天1次，3—4天后改为口服400mg，每天1次，连用6—7天，然后对两种方案进行成本-效果分析。结果两组在临床疗效、不良反应发生率及细菌清除率方面差异无统计学意义（P〉0．05）；但A组的医疗费用却高于B组（P〈0．01）。结论加替沙星序贯疗法与单纯静脉滴注相比更安全，更经济合理。     

SARS与细菌性典型肺炎的胸部CT特征对比分析

目的：探讨重症急性呼吸综合征(SARS)与细菌性典型肺炎胸部CT特征的异同．方法：回顾性分析28例SARS胸部CT表现与细菌性典型肺炎做对比结果：本组28例患者肺部病变初期多为单发病灶，在右侧外带胸膜下常见。片状磨玻璃样密度病变影存在于各期，而细菌性典型肺炎未见、发病初期和进展期肺容积变小?而细菌性典型肺炎多无此特点。进展期大多数发展为双肺由下至上痛变、恢复期病变由最晚受侵部位消退，遗留纤维化多为最早发生病变部位?而典型肺炎多从近肺门侧开始吸收，进展期局限的肺段、肺叶发展至多个肺叶、肺段，进展较迅速。而细菌性典型肺炎多为单独的肺叶、肺段．恢复期由弥漫性多发病变转变为局限病变，部分病人有肺部纤维化发生，而细菌性典型肺炎大多数吸收较完全，不遗留肺纤维化。结论：SARS所存在的急性间质性肺炎和急性肺炎可利用CT动态检查较准确地与细菌性典型肺炙加以区别。     

SARS死亡病例的实验室检查特点

目的：了解严重急性呼吸综合征(SARS)死亡病例的临床特点，为SARS重症病例的诊断、治疗及预后判断提供帮助。方法：对我院2003年1月至4月底收治的102例确诊非典患者中的5例死亡病例的流行病学及实验室检查资料进行回顾性分析。结果：死亡病例均为男性，平均49岁，从发病到入院平均7．6d，从住院到确诊平均1．2d；从住院到死亡平均14．4d，从发病到死亡平均为22d。死亡病例粒细胞总数和百分比均明显升高，多数患者淋巴细胞计数和百分比降低(4／5)，血红蛋白均呈进行性下降。死亡患者除已见报道的ALT、AST、LDH、CK升高及低钙血症外，GLU均明显高于正常而ALB均明显降低；大多数患者TP、PA等多项生化指标均出现明显下降而脱氧血红蛋白百分率(HHb)明显上升，同时伴有低磷、低镁血症。结论：SARS死亡病例多项实验室指标均会出现明显异常，动态监测这些指标有助于SARS患者的诊断、治疗及预后判断。     

5株SARS-CoV部分基因序列比较分析

目的　分析SARS CoV部分结构区的基因序列 ,了解其变异程度。方法　采用套式PCR法扩增各结构区基因 ,对阳性PCR产物进行克隆和测序 ,并对序列进行分析。结果　完成了LC1株病毒的M、N、E和S基因的扩增和克隆 ,对LC2、LC3、LC4和LC5株病毒的M区基因进行了扩增和克隆。序列分析显示各结构基因的核苷酸序列与已报道的 18株序列的同源性在 99%以上。结论SARS CoV的基因序列较保守 ,有利于PCR诊断试剂和预防用疫苗的研制。     

可吸收球囊椎体成形术治疗胸腰椎爆裂骨折的实验研究

[目的]探讨结合短节段椎弓根螺钉系统撑开复位内固定的可吸收球囊椎体成形术治疗胸腰椎爆裂骨折的生物力学性能变化。[方法]采集6具新鲜固定湿润成人尸体胸腰椎标本，制成T11-L1，L2～4、L1～3节段标本10个，用自由落体撞击试验造成中间椎体爆裂型骨折，行APF椎弓根螺钉撑开复位，经椎弓根于伤椎椎体内置入可吸收高分子材料-DL-乳酸与ε-己内酯（70：30）的共聚物（PDLLA-CL）制作的可吸收球囊，注入自固化磷酸钙骨水泥行可吸收球囊椎体成形术。分别于骨折前、骨折撑开复位椎体成形术后，用万能材料试验机测定中间椎体在前屈、后伸、侧屈状态下应力-应变、轴向刚度变化及扭转应力下刚度的变化。[结果]伤椎经可吸收球囊椎体成形术治疗后，抗压强度均有所增加，前屈为8％，后伸15％，侧屈9．8％，其中以后伸时增加显著（P〈0．05）。治疗后的轴向刚度普遍得到提高，与骨折前相比，前屈增加11％，后伸增加8％，侧屈增加3％。治疗后椎体在扭转应力下刚度小于骨折前，但两者差异不明显（P〉0．05）。[结论]（1）结合短节段椎弓根螺钉系统撑开复位内固定的可吸收球囊椎体成形术，有助于伤椎的重建，术后脊柱的生物力学特性接近骨折前水平；（2）可吸收球囊椎体成形术治疗胸腰椎爆裂骨折，在避免骨水泥渗漏可能导致的潜在危险之前提下，从本质上恢复胸腰椎爆裂型骨折伤椎椎体结构的完整性，恢复其高度，从而恢复和维持脊柱的生理弧度，防止继发性脊柱后凸畸形变引起的迟发性腰背痛及脊髓、神经损伤，以从根本上解决单纯用经椎弓根内固定器治疗胸腰椎爆裂型骨折遗留的并发症，为临床治疗胸腰椎爆裂骨折提供了一个新的方法。