成人呼吸系统疾病中呼吸道合胞病毒的监测

目的:了解呼吸道合胞病毒(RSV)在成人呼吸系统疾病中的发病情况。方法:对呼吸科住院患者253例及同期健康体检者200例静脉血清用酶联免疫法(ELISA)测定RSV抗体IgM。结果:对照组阳性12例,阳性率6%;患者组阳性37例,阳性率14.6%,其中慢性阻塞性肺病(COPD)、肺炎与对照组比较差异有显著性(P<0.05);急性支气管炎、肺间质纤维化、结核性胸膜炎与对照组比较差异有显著性(P<0.01)。本组患者秋冬季发病较多,阳性率19.5%,春夏季阳性率9.6%,二者相比差异有显著性(P<0.05)。结论:RSV是成人呼吸道感染的重要病原,可引起下呼吸道炎症(如COPD、肺炎、急性支气管炎、肺间质疾病等)的发生和反复发作,应引起重视。     

术前、术中肺通气功能与术后呼吸衰竭的关系

目的探讨机械通气时呼吸力学与术前肺功能的关系．确定术前通气功能参数能否预测术后呼吸衰竭。方法择期行肺切除术的原发性肺癌病人100例．ASAⅠ级或Ⅱ级，术前测定肺功能：一秒用力呼气容量（FEV1）、用力肺活量（FVC）、一秒用力呼气量与用力肺活量之比（FEV1／FVC％）、最大肺活量（VC）、最大通气量（MVV）、75％肺活量位用力呼气流速（FEh）、最大中期呼气流速（MMEFm）、功能残气量（FRC）、残气量与肺总量之比（RV/TLC％）；测定脉冲震荡肺功能：共振频率（Fres）、呼吸总阻抗（Zres）、中心阻力（Rc）、5Hz和20Hz时粘性阻力（R5、R30）。分别记录插管后机械通气初始和开胸单肺通气后双肺气道峰压（Tpeak）、双肺胸肺顺应性（TCT）和单肺气道峰压（Opeak）、单肺胸肺顺应性（OCT），取其平均值。Opeak和OCT与身高、体重及肺功能的关系采用多元逐步回归。一般情况和肺功能与术后呼吸衰竭的关系采用非条件Logistic回归分析。根据术后是否发生呼吸衰竭分为2组：呼吸衰竭组（RF）和非呼吸衰竭组（NRF）。结果Opeak与Zres、身高、体重和FEF。呈线性关系（R2=0．504），OCT与Zres、身高、VC和RVfrLC％呈线性关系（R^2=0.602）。与NRF组比较，RF组FEV1、FVC、FEV1／FVC％、MVV、MMEFw均降低（P〈0．01）。年龄≥60岁的老年患者FEV1≤60％、FEV1／FVC≤60％、MVV≤50％、MMEn％≤35％时，RF组术后呼吸衰竭发生率高于NRF组（P〈0．05）。Logistic回归表明．年龄和MVV是术后呼吸衰竭的两个主要影响因素。结论术中单肺通气时的气道峰压和胸肺顺应性分别与身高、体重和术前肺功能呈线性相关。中度肺功能减退的老年患者行胸科手术后发生呼吸衰竭的风险性大：年龄和MVV是术后呼吸衰竭的两个主要影响因素。     

The impact of COVID-19 and masking practices on pertussis cases at a large academic medical center (2019-2021)

We reviewed cases of Bordatella pertussis (B. pertussis) cases in ambulatory clinics at a large academic health care institution in Los Angeles from 2019-2021. Public health prevention measures during the Coronavirus disease 19 (COVID-19) pandemic impacted the number of pertussis cases identified.     

健康中老年人肺功能下降与呼吸中枢驱动变化的关系

目的 探讨健康中老年人肺功能下降与呼吸中枢驱动变化的关系. 方法 随机选择8例健康中老年人及8例性别匹配的健康青年人,平均年龄分别为(57.3±5.0)岁和(28.3±3.4)岁,检测其肺功能.同时,通过多导食道电极记录膈肌肌电反映呼吸中枢驱动,观察静息状态下及最大用力吸气时的膈肌肌电. 结果 中老年组平均肺活量(VC)(3.2±0.5)L,显著低于青年组(4.0±0.8) L(t=-2.27,P＜0.05)；中老年人最大用力吸气动作时的膈肌肌电与青年人相似,分别为(172.2±54.6)μV与(175.0±55.7)μV(t=- 0.10,P=0.921)；中老年人安静状态下的潮气量及每分通气量与青年人相似,但其呼吸中枢驱动占最大值的百分数显著高于青年人,分别为( 27.8+12.9)％与(16.4±7.2)％(t=2.18,P＜0.05):中老年人呼吸中枢驱动有效性比青年人小1倍,分别为(62.7±23.2)％与(128.6±96.2)％. 结论 中老年人的呼吸中枢驱动储备低于青年人,肺功能随增龄减退并不是因为呼吸中枢驱动下降,而可能是因为肺结构本身改变所致.     

Diagnóstico microbiológico de las infecciones virales respiratorias en el paciente adulto

Conventional techniques for the diagnosis of respiratory viruses are still being used, although molecular methods are now considered as a gold standard in this field. Molecular techniques have a great number of advantages such as an excellent sensitivity, specificity, adaptability to emerging viruses, capability for multiplex and for automation. With all the available repertoire of techniques for microbiological diagnosis, the knowledge relative to respiratory viruses is growing up not only for new aetiological agents but also for its epidemiology. The advances in molecular and non-molecular fast diagnostic methods for one or more respiratory viruses allow quick decisions in the management of the patient. However, there are also disadvantages. The great sensitivity of molecular techniques has meant a significant increase in the rate of multiple detections of respiratory viruses, whose clinical involvement is difficult to interpret. Finally, it remains to show whether the use of new techniques, of high cost, in the microbiological routine diagnosis of acute respiratory viral infections in the hospitalized patient, is cost effective.     

Implementation of a respiratory protection program within healthcare facilities during the COVID-19 pandemic- lessons learned

The use of fit tested respirators in the workplace is required to protect health workers against airborne pathogens. The COVID-19 pandemic required rapid upscaling of fit testing which was achieved using the framework of a respiratory protection program. Implementing and sustaining such a program in the midst of a pandemic was challenging and required clear direction from a lead agency combined with stakeholder engagement.     

Coinfección vírica en las infecciones respiratorias infantiles

IntroductionThe introduction of molecular techniques has enabled better understanding of the etiology of respiratory tract infections in children. The objective of the study was to analyze viral coinfection and its relationship to clinical severity.MethodsHospitalized pediatric patients with a clinical diagnosis of respiratory infection were studied during the period between 2009-2010. Clinical and epidemiological data, duration of hospitalization, need for oxygen therapy, bacterial coinfection and need for mechanical ventilation were collected. Etiology was studied by multiplex PCR and low-density microarrays for 19 viruses.ResultsA total of 385 patients were positive, 44.94% under 12 months. The most frequently detected viruses were RSV-B: 139, rhinovirus: 114, RSV-A: 111, influenza A H1N1-2009: 93 and bocavirus: 77. Coinfection was detected in 61.81%, 36.36% with 2 viruses, 16.10% and 9.35% with 3 to 4 or more. Coinfection was higher in 2009 with 69.79 vs. 53.88% in 2010. Rhinovirus/RSV-B on 10 times and RSV-A/RSV-B on 5 times were the most detected coinfections. Hospitalization decreased with greater number of viruses (P < 0,001). Oxygen therapy was required by 26.75% (one virus was detected in 55.34% of cases). A larger number of viruses resulted in less need for oxygen (P < 0,001). Ten cases required mechanical ventilation, 4 patients with bacterial coinfection and 5 with viral coinfection (P = 0,69).ConclusionsAn inverse relationship was found between the number of viruses detected in nasopharyngeal aspirate, the need for oxygen therapy and hospitalization days. More epidemiological studies and improved quantitative detection techniques are needed to define the role of viral coinfections in respiratory disease and its correlation with the clinical severity.     

The effect of the outbreak of COVID-19 on respiratory physicians and healthcare in Japan: Serial nationwide surveys by the Japanese Respiratory Society

BackgroundThe impact of the outbreak of COVID-19 on the work of respiratory physicians in Japan has not yet been evaluated. The study investigates the impact of the outbreak on respiratory physicians’ work over time and identifies problems to be addressed in the future.MethodsWe conducted a web-based survey of respiratory physicians in 848 institutions. The survey comprised 32 questions and four sections: Survey 1 (April 20, 2020), Survey 2 (May 27, 2020), Survey 3 (August 31, 2020), and Survey 4 (December 4, 2020).ResultsThe mean survey response rate was 24.9%, and 502 facilities (59.2%) participated in at least one survey. The proportion of facilities that could perform PCR tests for diagnosis and more than 20 tests per day gradually increased. The percentage capable of managing extracorporeal membrane oxygenation (ECMO) or more than five ventilators did not increase over time. The proportion that reported work overload of 150% or more, stress associated with lack of personal protective equipment (PPE), and harassment or stigma in the surrounding community did not sufficiently improve.ConclusionWhile there was an improvement in expanding the examination system and medical cooperation in the community, there was no indication of enhancement of the critical care management system. The overwork of respiratory physicians, lack of PPE, and harassment and stigma related to COVID-19 did not sufficiently improve and need to be addressed urgently.     

新型冠状病毒肺炎呼吸支持手段介入的时机与策略

呼吸支持技术作为救治重症新型冠状病毒肺炎的有效手段,正确应用会有效改善氧合、降低病死率.但不同呼吸支持技术介入的时机、如何合理应用在一定程度上直接关系到治疗的成败.本文就作者团队临床救治重症新型冠状病毒的经验结合国内外相关研究成果进行阐述,希望对当前救治重症新型冠状病毒有所帮助.     

The Effects of Inhaled Albuterol and Salmeterol in 2- to 5-Year-Old Asthmatic Children as Measured by Impulse Oscillometry*

The functional assessment of the response to bronchodilators in 2- to 5-year-old asthmatic children is technically difficult. For this reason, there have been no reports on the effects of long-acting bronchodilators, such as salmeterol, in this age group. Of the several techniques available for measuring resistance to airflow, forced oscillation remains the most adaptable to young children and the most practical for research and clinical use. In this study we used the Jaeger MasterScreen Impulse Oscillometry System to assess the response of 2 to 5 year-old asthmatic children to an inhaled long-acting bronchodilator, salmeterol, by comparing it to the effect of a standard dose of the short-acting bronchodilator, albuterol. We performed a placebo-controlled, randomized, crossover study in 10 children aged 2 to 5 years who had a history of physician-diagnosed asthma and who were not on regular controller therapy. At weekly intervals after baseline measurements of reversibility, each child received two inhalations from an albuterol metered-dose inhaler (MDI) with a spacer (200 µg), or placebo MDI with spacer, or two inhalations from a salmeterol MDI (50 µg), or 50 µg from a salmeterol Diskus®. Measurements were obtained at 5, 30, 60, 360, and 540 min, the last time interval only on the salmeterol days. Based on previous studies, total respiratory system reactance at 5 Hz (X₅), calculated by the MasterScreen computer from mouth pressure and flow data, was used as the primary efficacy variable. The mean intra-individual variability in X₅ was 10.5% (range 3.6% to 17.9%). The mean (SE) changes from baseline X₅ at each time point were as follows: for placebo, 9.6 (3.0), 10.1 (2.6), 5.1 (2.9), 6.1 (3.5), p=0.36 vs. baseline; after treatment with albuterol, 32.7 (3.8), 53.9 (1.2), 47.3 (5.4), 18.1 (5.8), p<0.01 vs. baseline at all time points; after salmeterol MDI, 16 (6.4), 28.9 (5.2), 32.7 (3.9), 34.6 (4.4), 31.2 (4.8), p<0.05 at 60, 360, and 540 min; and after salmeterol Diskus®, 16.4 (4.0), 16.9 (6.6), 27.8 (5.9), 28.6 (5.6), 33.8 (4.0), p<0.05 at 540 min. No significant adverse events or electrocardiographic changes were noted at any time. Impulse oscillometry is an acceptable method of assessing airway responses to bronchoactive drugs in this age group. Compared to albuterol and to its effect in older children and adults, the response to salmeterol Diskus® appears to be somewhat blunted in this age group. The MasterScreen system is well suited for pharmacodynamic studies and clinical investigations in pre-school-aged children.     

Air stacking: effects on pulmonary function in patients with spinal muscular atrophy and in patients with congenital muscular dystrophy

OBJECTIVE:

Respiratory complications are the main causes of morbidity and mortality in patients with neuromuscular disease (NMD). The objectives of this study were to determine the effects that routine daily home air-stacking maneuvers have on pulmonary function in patients with spinal muscular atrophy (SMA) and in patients with congenital muscular dystrophy (CMD), as well as to identify associations between spinal deformities and the effects of the maneuvers.

METHODS:

Eighteen NMD patients (ten with CMD and eight with SMA) were submitted to routine daily air-stacking maneuvers at home with manual resuscitators for four to six months, undergoing pulmonary function tests before and after that period. The pulmonary function tests included measurements of FVC; PEF; maximum insufflation capacity (MIC); and assisted and unassisted peak cough flow (APCF and UPCF, respectively) with insufflations.

RESULTS:

After the use of home air-stacking maneuvers, there were improvements in the APCF and UPCF. In the patients without scoliosis, there was also a significant increase in FVC. When comparing patients with and without scoliosis, the increases in APCF and UPCF were more pronounced in those without scoliosis.

CONCLUSIONS:

Routine daily air-stacking maneuvers with a manual resuscitator appear to increase UPCF and APCF in patients with NMD, especially in those without scoliosis.     

The use of REE determination in a clinical setting applied to respiratory disease

The determination of a patient's nutritional condition is an important moment of clinical evaluation in everyday experience. Quite often, it is important to identify symptoms, signs and objective parameters that may reveal a malhourished condition. To satisfy this request, clinicians recur to clinical examination and biochemical tests. It is also possible to use indirect calorimetry. Through the evaluation of oxygen consumption (VO₂) and carbon dioxide production (VCO₂), indirect calorimetry permits the respiratory quotient (RQ) to be calculated and the exact energy consumption during resting conditions to be determined. This technology, currently used in research departments and in hospital units, is more accurate for the estimation of resting energy expenditure (REE) than the Harris-Benedict equation, especially in the case of patients affected by respiratory diseases or other systemic conditions. The evaluation of REE through indirect calorimetry is a useful monitoring and prognostic index in acutely and chronically ill patients.     

呼吸疾病研究所呼气相气道内负压法检测呼气流速受限在支气管哮喘患者中的应用

目的 探讨支气管哮喘(简称哮喘)患者呼气流速受限(EFL)与呼吸困难严重程度的相关性,观察吸入支气管扩张剂对哮喘患者EFL的影响.方法 采用呼气相气道内负压法(NEP)检测65例哮喘患者支气管扩张试验前、后(吸入沙丁胺醇400 μg)EFL情况.结果 65例哮喘患者中有26例(40%)出现EFL,其中11 例仅仰卧位时出现,15例仰卧位及坐位均出现.EFL和无EFL者(N-EFL)第一秒用力呼气容积占预计值百分比(FEV1占预计值%)分别为(52±15)%、( 77±18)%,两组比较差异有统计学意义(t＝5.822,P＜0.01).仅仰卧位有EFL(S-EFL)者和仰卧位、坐位均有EFL(SS-EFL)者FEV1占预计值%分别为(64±10)%、(43±12)%,两组比较差异有统计学意义(t值分别为2.283、6.694,P分别＜0.01、＜0.05).3分法和5分法EFL均与FEV1占预计值%呈负相关(r值分别为-0.637、-0.630,P均＜0.01).第一秒用力呼气容积(FEV1)与加拿大医学研究委员会推荐的呼吸困难严重程度分级标准(MRC评分)呈负相关(r=-0.501,P＜0.01),3分法和5分法EFL均与MRC评分呈正相关(r值分别为0.627、0.636,P均＜0.01).17例FEV1占预计值%＜70%并存在EFL的患者吸入沙丁胺醇后,9例EFL完全消失,5例从SS-EFL变为S-EFL,吸入沙丁胺醇后3分法和5分法EFL评分均较吸入前差异有统计学意义(t值分别为6.769、6.010,P均＜0.01).结论 与FEV1比较,EFL与哮喘患者呼吸困难严重程度相关性更强,可作为评价患者呼吸困难严重程度更可靠的客观指标.哮喘患者EFL可被吸入支气管扩张剂逆转,即表现为可逆性EFL.     

Rehospitalisations for respiratory disease and respiratory syncytial virus infection in preterm infants of 29-36 weeks gestational age

BACKGROUND: To evaluate rates of rehospitalisation due to respiratory illness in preterm infants of 29-36 weeks gestation without chronic lung disease. PATIENTS AND METHODS: Retrospective single centre cohort study including infants from 1998 to 1999 with follow-up over two respiratory syncytial virus (RSV) seasons. RESULTS: Of 435 infants included 61 infants (14%) experienced 78 rehospitalisations. The overall RSV attack rate was 4.4% over two consecutive RSV seasons for infants below 6 months of age at onset of RSV season (7.7 and 1.1%, respectively, p=0.015), with significant differences between infants of 29-32 and 33-36 weeks gestational age (10.5% vs. 2.3%, p=0.008). None of the infants needed mechanical ventilation or admission to the intensive care unit. Infants with RSV infection were younger of age (mean 4.2 vs. 8.2 months; p=0.015), had longer stays at the hospital (11.5 vs. 7.0 days; p=0.006), and more severe courses of disease (score 3.0 vs. 1.8; p<0.001). Additional risk factors for RSV infection were multiple gestation (OR 5.5; CI 95% 1.439-21.028) and congenital heart disease (OR 4.2; CI 95% 1.005-17.669). CONCLUSION: The total burden of respiratory disease and RSV infection in this population was low. A lower gestational age, multiple gestation, and congenital heart disease were associated with increased risk of RSV infection.     

Diurnal Variability of Peak Expiratory Flow

Diurnal variation in peak expiratory flow (PEF_var) has been suggested as a surrogate for bronchial hyperreactivity, and may be a useful tool in the management of bronchial asthma. Several indices have been postulated to measure PEF_var; however, the number of daily measurements and the timing of recordings are not clearly established. Although several investigators have defined ranges for PEF_var in healthy individuals, clear cutoff values that differentiate asthmatics from others are not available. Despite this shortcoming, PEF_var is an important measurement in screening and diagnosis of asthma in population-based studies, as well as for assessing disease severity and prognosis. Treatment of asthma with either inhaled corticosteroids or bronchodilators may influence the magnitude of PEF_var in a complex fashion. Therefore, PEF_var should only be interpreted in conjunction with other clinical and laboratory information.     

A community-based, time-matched, case-control study of respiratory viruses and exacerbations of COPD

Respiratory viruses are associated with severe acute exacerbations of chronic obstructive pulmonary disease (COPD) in hospitalized patients. However, exacerbations are increasingly managed in the community, where the role of viruses is unclear. In community exacerbations, the causal association between viruses and exacerbation maybe confounded by random fluctuations in the prevalence of circulating respiratory viruses. Therefore, to determine whether viral respiratory tract infections are causally associated with community exacerbations, a time-matched case-control study was performed. Ninety-two subjects (mean age 72 yrs), with moderate to severe COPD, (mean FEV(1) 40% predicted), were enrolled. Nasopharyngeal swabs for viral multiplex polymerase chain reaction and atypical pneumonia serology were obtained at exacerbation onset. Control samples were collected in synchrony, from a randomly selected stable patient drawn from the same cohort. In 99 weeks of surveillance, there were 148 exacerbations. Odds of viral isolation were 11 times higher in cases, than their time-matched controls (34 discordant case-control pairs; in 31 pairs only the case had virus and in three pairs only control). Picornavirus (26), influenza A (3), parainfluenza 1,2,3 (2), respiratory syncytial virus (1), and adenovirus (1) were detected in cases while adenovirus (1) and picornavirus (2) were detected in controls. In patients with moderate or severe COPD the presence of a virus in upper airway secretions is strongly associated with the development of COPD exacerbations. These data support the causative role of viruses in triggering COPD exacerbations in the community.     

Central fatigue of the rabbit diaphragm

This study evaluates the importance of central fatigue of the diaphragm in rabbits subjected to inspiratory muscle resistive loading (IRL). Ten rabbits were subjected to constant IRL while unanesthetized and breathing supplemental oxygen. During 10–20 minutes of spontaneous breathing against IRL, there were no significant changes in arterial oxygen saturation or in diaphragm contractility, measured by the quasi-static transdiaphragmatic pressure response to a 0.3-sec train of 100 Hz supramaximal phrenic nerve stimuli. After an initial decrease due to application of the load, the minute ventilation decreased further, by an average of 15%, while arterial pCO₂ increased to an average of 59 mmHg (p < 0.05). The normalized diaphragm pressure-time index initially increased from 0.02 to 0.18 during IRL, then decreased an average of 29% (p < 0.05). These results show that severe IRL causes a decrease in the level of diaphragmatic effort over time despite increased chemical drive and despite a preserved ability of the muscle to respond to phrenic nerve stimuli. This adaptation may help to prevent peripheral diaphragm fatigue.