Predicting the need for hospitalization in children with acute asthma

In an attempt to identify factors which influence the decision of physicians to admit patients with acute asthma to the hospital, we studied prospectively 200 children (age 5.6 +/- 3.1 years, mean +/- SD) presenting to our emergency room with acute asthma. The children were assessed on arrival, and on disposition from the Emergency Room by one of the investigators. After obtaining historic data, a clinical score was assigned, and oxygen saturation and pulmonary function were measured. Of the 134 (67 percent) children who were discharged home from the Emergency Room, five returned within seven days and one was subsequently admitted. The clinical score on disposition was the sole variable found to best predict the decision for hospitalization (sensitivity 73 percent, specificity 95 percent). Of the variables obtained at presentation, the resulting decision tree found the clinical score to predict the decision for hospitalization (sensitivity 79 percent, specificity 75 percent). When the individual components of the clinical score were analyzed, the degree of dyspnea, as assessed by the investigator, was chosen as the rule to predict the hospitalization decision (sensitivity 88 percent, specificity 71 percent). We conclude that the decision with respect to the need for hospitalization in acute childhood asthma, is in practice based mainly on careful clinical evaluation. Pulmonary function and SaO2 measurements, although helpful adjuncts in the assessment of acute asthma, do not appear to contribute to the identification of patients who need hospital admission.     

Effective argon-FRC with a rebreathing technique in children with acute asthma

In children with asthma the measurement of functional residual capacity (FRC) with standard dilution techniques requires long rebreathing times of the inert gas, i.e., helium, to reach alveolar units with long time constants. A modification of the argon-freon-22 rebreathing technique enables argon to dilute in the readily accessible lung volume and potentially can give a measurement of FRC. However, the rebreathing tests cannot be prolonged for more than 1 min thus allowing argon to reach only the rapidly accessible lung units which are grossly useful in gas exchange (effective FRC, EFRC). The aim of this study was to measure the EFRC and standard lung function in children with acute severe asthma, assess their response to nebulized salbuta-mol, and evaluate the relations of the EFRC response to baseline spirometric measurements. Twenty-four asthmatic children who were admitted to the hospital with an acute asthma attack had spirometry and triplicate EFRC measurements before and after treatment with nebulized salbutamol. Eighteen patients had repeated the respiratory tests 50 days later when they had fully recovered. A significant proportion (28.9%) of the argon traces obtained at baseline before treatment did not equilibrate. However, in the great majority of these tests the oscillation of the argon traces over the last 3 breaths of the test was < 5% of the simultaneous argon concentration. The EFRC values derived from the argon traces with minimal oscillation (< 5%) were reduced during the acute asthma attack when compared with the paired values obtained after recovery (P = 0.03). The administration of salbutamol caused a fall from the baseline EFRC (P = 0.05). There was a significant correlation between the EFRC and FVC values (expressed as percentage of normal) in all 3 of the test occasions. The changes in the pretreatment and posttreatment EFRC values induced by recovery were correlated to the corresponding changes in the spirometric indices. In conclusion, rebreathing techniques can give quick measurements of EFRC in patients with acute asthma. The changes induced by recovery in baseline and postsalb-utamol EFRC follow the pattern of the corresponding spirometric indices changes and not the expected typical FRC pattern. © 1995 Wiley-Liss, Inc.     

Measurement of inspiratory flow in children with acute asthma

Dry-powder inhalers (DPIs) have been proposed for treatment of acute asthma. Different DPIs vary in their inspiratory resistance and have different recommended optimal peak inspiratory flows (PIFs). Reduced PIF during acute asthma may result in inadequate drug delivery to the lungs. Our aim was to measure the inspiratory flow in relation to inspiratory resistance during acute asthma in children presenting to the emergency room. School-age (range, 6-18 years) children were referred to the emergency room for acute asthma. PIF measurements were performed by In-Check Dial trade mark device with simulated airflow resistances equivalent to Turbuhaler, Diskus, and free flow. Percent change in PIF between remission and acute asthma (%Delta) was correlated with percent change in clinical score (CS) and percent change in spirometry in children <9 and >9 years old. Thirty-three children (21 males) participated. PIF with simulated Turbuhaler resistance was significantly lower than with simulated Diskus resistance in both acute and remission states (P < 0.0001). PIF with simulated Turbuhaler resistance increased from 62.1 +/- 15.3 (acute) to 74.4 +/- 16.5 l/min (remission, P < 0.0001), while with Diskus it rose from 72.6 +/- 20.5 to 91.1 +/- 18.9 l/min (P < 0.0001). Turbuhaler %Delta PIF correlated with %Delta FEV(1) (P = 0.01) and with %Delta CS (P = 0.0001). A lesser degree of correlation was observed while using Diskus resistance and in children above 9 years old. During acute asthmatic attacks, PIF is reduced; this reduction is particularly prominent in young children who use a high-resistance device. However, the PIF generated is generally within the values considered compatible with adequate lung deposition with both Diskus and Turbuhaler.     

Oscillometric and spirometric bronchodilator response in preschool children with and without asthma

BACKGROUND:

Bronchodilator responses (BDR) are routinely used in the diagnosis and management of asthma; however, their acceptability and repeatability have not been evaluated using quality control criteria for preschool children.

OBJECTIVES:

To compare conventional spirometry with an impulse oscillometry system (IOS) in healthy and asthmatic preschool children.

METHODS:

Data from 30 asthmatic children and 29 controls (two to six years of age) who underwent IOS and spirometry before and after salbutamol administration were analyzed.

RESULTS:

Stable asthmatic subjects significantly differed versus controls in their spirometry-assessed BDR (forced expiratory volume in 1 s [FEV₁], forced vital capacity and forced expiratory flow at 25% to 75% of forced vital capacity) as well as their IOS-assessed BDR (respiratory resistance at 5 Hz [Rrs₅], respiratory reactance at 5 Hz and area under the reactance curve). However, comparisons based on the area under the ROC curve for ΔFEV₁ % initial versus ΔRrs₅ % initial were 0.82 (95% CI 0.71 to 0.93) and 0.75 (95% CI 0.62 to 0.87), respectively. Moreover, the sensitivity and specificity for ΔFEV₁ ≥9% were 0.53 and 0.93, respectively. Importantly, sensitivity increased to 0.63 when either ΔFEV₁ ≥9% or ΔRrs₅ ≥29% was considered as an additional criterion for the diagnosis of asthma.

CONCLUSION:

The accuracy of asthma diagnosis in preschool children may be increased by combining spirometry with IOS when measuring BDR.     

Correlation of clinical score to pulmonary function and oxygen saturation in children with asthma attack

BackgroundThe aim of this study is to demonstrate the importance of the relation between clinical score, pulse oximetry and spirometric tests in an asthma attack.MethodsIn this randomized, double blind, observational study, 110 children (age 2-15 years) with an asthma attack who were admitted to emergency room were evaluated. Patient history, physical examination, clinical score and oxygen saturation were recorded in all patients; however pulmonary function tests were obtained only in 54 children who were over 5 years of age. The clinical score was derived from respiratory rate, wheezing, dyspnea and retractions.ResultsBoth oxygen saturation and spirometric tests were found to be significantly correlated with the clinical score in children.ConclusionThe clinical score could be used for assessing the severity of the asthma attack particularly in developing countries where laboratory facilities are not available or pulmonary function tests are not feasible.     

Childhood asthma following hospitalization with acute viral bronchiolitis in infancy

A prospective follow-up of 48 infants hospitalized with respiratory syncytial virus bronchiolitis in the first year of life revealed that 44 of these infants had symptoms suggestive of asthma in the 5 years following their initial illness (cumulative prevalence 92%). Symptoms became less frequent and less troublesome during the follow-up period. Thirty-five of these children visited the laboratory for clinical examination, pulmonary function testing, and histamine challenge. Twenty-five children were believed to have clinical evidence of asthma at the time of the laboratory visit (point prevalence 71%). Five children were unable to perform pulmonary function tests; 25 of the remaining 30 (67%) had a positive histamine challenge test. No relationship could be demonstrated between a clinical diagnosis of asthma, a family history of atopy, and the results of histamine challenge testing. These results question the relationship between the results of bronchial provocation tests and clinical asthma in this age group.     

Determinants of tidal flow volume loop indices in neonates and children with and without asthma

The tidal flow volume (TFV) loop ratios of (1) time to peak flow (tPTEF ) to total expiratory time (tE ) [tPTEF /tE ] and (2) volume to peak flow (VPTEF ) to expired volume (VE ) [VPTEF /VE ] are reported to decrease with age in early life, and to decrease in subjects with obstructive airways disease (OAD). However, the mechanisms behind these changes are not well known. Thus, we reanalyzed data from 24 healthy neonates (mean birthweight: 3.49 kg ± 0.42 kg (SD)), 26 presently asymptomatic asthmatic children (age: 33 ± 21 months), and 26 controls (age: 34 ± 19 months) to elucidate what is responsible for the changes in these ratios in health and disease. Lung function was measured by TFV loops (SensorMedics 2600) at 1 hour of life and on the following day in the neonates, and before and after inhaled nebulized salbutamol (0.05 mg/kg) in the asthmatics and their controls. The observed decreases in mean tPTEF /tE and VPTEF /VE from 1 hour to 1 day of life (neonates) were entirely due to increased tE and VE , respectively secondary to a decrease in respiratory rate (P = 0.03). In asthmatics (young children), the decreased baseline tPTEF /tE and VPTEF /VE were due to lower tPTEF and VPTEF , with no significant differences in tE e and VE in asthmatics and controls. The improved ratios in asthmatic children following inhalation of a bronchodilator were mainly due to increased tPTEF and VPTEF . Our observations point out the importance of evaluating both tPTEF and either tPTEF /tE or VPTEF /VE when attempting to differentiate between changes in ratios that are related to age versus changes that reflect underlying obstructive airways disease. Pediatr. Pulmonol. 1997; 24:391–396. © 1997 Wiley-Liss, Inc.     

ITBI和GEDI评估心源性肺水肿患者心脏前负荷变化的局限性

目的研究胸腔内血容积指数（ITBI）和全心舒张末容积指数（GEDI）能否充分评估心源性肺水肿患者心脏前负荷状态。方法对8例心源性肺水肿患者,应用肺动脉导管（SWAN-GANZ）和脉搏指示连续心输出量（PiCCO）监测血流动力学,持续肾脏替代治疗（CRRT）减轻心脏前负荷,分别监测CRRT开始时、8h、16h和24h的中心静脉压（CVP）、肺动脉楔压（PAWP）、ITBI、GEDI等血流动力学指标,分析随着前负荷的减少,这些指标的变化。结果在超滤8h后CVP和PAWP下降即出现显著变化（17．3±2．5掷．16．1±2．2和39．6±4．2％36．0±4．2,P〈0．01）,并随着超滤时间延长,下降更明显,而ITBI和GEDI到超滤24h才出现显著下降（971±133VS．898±51和779±103vs.719±40,P〈0．05）;CVP、PAWP、ITBI和GEDI随着前负荷减少的变异度分别为（16．29±10．37）％、（19．35±9．86）％、（2．95±6．02）％和（3．25±6．03）％。结论IBTI和GEDI在评估心源性肺水肿患者的前负荷状态时敏感性低于CVP和PAWP。     

Optimizing inhaled corticosteroid therapy in children with chronic asthma

Asthma is the most common chronic illness among children, and inhaled corticosteroids (ICS) are the most effective long-term therapy available for suppressing airway inflammation in persistent asthma. While the primary aim of ICS therapy is good efficacy with minimal side effects, early diagnosis and treatment of asthma can also improve asthma control and normalize lung function, and may prevent irreversible airway injury. Poor patient compliance is a major barrier to treatment. Simplified dosing regimens (e.g., once-daily administration), good inhaler technique, and education of the patient/caregiver should improve patient compliance. Concerns over ICS therapy are often based on the potential for systemic effects associated with oral corticosteroids (e.g., effects on bone mineral density, or growth suppression in children). Since adverse events are associated with high doses of ICS, the dose in all patients should be titrated to the minimum effective dose required to maintain control. Optimal distribution of an ICS in the lungs rather than the systemic compartment is affected by several factors, including the drug's pharmacokinetic profile, inhaler type, inhaler technique, and drug particle size. For young patients unable to use a dry-powder inhaler or pressurized metered-dose inhaler, a nebulizer facilitates drug delivery through passive inhalation; ICS therapy in the form of budesonide inhalation suspension can be given to children with persistent asthma from 12 months of age. In conclusion, selecting a drug with good efficacy and minimal side effects, such as budesonide, together with an easy-to-use delivery system and ongoing patient/caregiver education, is important in optimizing ICS therapy for children with persistent asthma.     

Relationship between pulmonary function and physical activity in daily life in patients with COPD

BACKGROUND: It remains unclear how closely the physical inactivity observed in patients with Chronic Obstructive Pulmonary Disease (COPD) relates to the severity of their airflow limitation. Furthermore, it is unknown whether spirometric variables such as maximal voluntary ventilation (MVV) and inspiratory capacity (IC) reflect the level of physical activity in daily life better than the forced expiratory volume in the first second (FEV(1)), the main spirometric variable used to determine the severity of COPD. The objective of the present study was to investigate the relationship between physical activity in daily life and the severity of COPD assessed by different spirometric variables: MVV, IC and FEV(1). METHODS: Forty patients with COPD (21 men; 68+/-7 years; FEV(1) 41+/-14% predicted) were performed spirometry and assessment of the physical activity level in daily life using an accelerometer (SenseWear Armband). RESULTS: MVV was significantly correlated to total energy expenditure per day, energy expenditure per day in activities demanding more than 3 metabolic equivalents (METs), number of steps per day and time spent per day in moderate and vigorous activities (0.42相似文献   

外周血白细胞介素-22在支气管哮喘患者中的表达及其临床意义

目的 通过分析白细胞介素(IL)-22在支气管哮喘中的表达,探讨IL-22是否参与支气管哮喘的发病机制及与疾病的关系.方法 采用实时定量聚合酶链式反应(Real-time PCR)和酶联免疫吸附试验(ELISA)分别测定对照组(10例)、哮喘组(17例)和哮喘缓解组(16例)中IL-22 mRNA和蛋白的表达.结果 哮喘组患者中IL-22 mRNA和蛋白表达明显高于哮喘缓解组和对照组.它的表达与哮喘患者第1秒用力呼吸容积占预计值百分比(FEV1％)和第1秒用力呼气容积占肺活量比值(FEV1/FVC％)呈负相关,而与哮喘严重程度评分(ASS)呈正相关.结论 IL-22可能在支气管哮喘的发病机制中起到一定作用,且与支气管哮喘的严重程度有一定关系.     

Contrasting pulmonary blood flow profiles in children with atrial and ventricular septal defects.

Instantaneous pulmonary blood flow profiles and other measures of haemodynamic functioning were studied in children with atrial septal defects (ASD) and children with ventricular septal defects (VSD) and normal pulmonary pressures and resistance at the time of defect closure. Though most parameters measured were comparable in the patient populations, several significant differences were found in the shape of the flow profile.     

呼气相气道内负压法检测呼气流速受限在慢性阻塞性肺疾病中的应用

目的探讨慢性阻塞性肺疾病(COPD)患者呼气流速受限(EFL)与呼吸困难严重程度的相关性,并观察吸入支气管扩张剂对 COPD 患者 EFL 的影响。方法采用呼气相气道内负压法(NEP)检测33例 COPD 患者支气管扩张试验前、后(吸入沙丁胺醇400μg)EFL 情况,其中男31例,女2例,年龄46～78岁,平均年龄(63±8)岁。结果 33例 COPD 患者中23例(70%)出现 EFL,其中11例(33%)仅仰卧位出现 EFL,12例(36%)仰卧位及坐位均出现 EFL。无 EFL 患者与 EFL 患者第一秒用力呼气容积占预计值百分比(FEV_1占预计值%)分别为(66±16)%和(31±10)%,差异有统计学意义(t=7.601、P<0.01),仰卧位及坐位均出现 EFL 患者的 FEV_1占预计值%最低[(24±7)%]。3分法和5分法 EFL 均与 FEV_1呈显著负相关(r=-0.836和-0.818,P 均<0.01)。3分法和5分法 EFL 均与医学研究委员会(MRC)推荐的呼吸困难严重程度分级评分标准(简称 MRC 呼吸困难评分)呈显著正相关(r=0.903和0.912,P均<0.01)。多元回归分析结果显示,5分法 EFL 和FEV_1对 MRC 呼吸困难评分的预测性均有统计学意义(标准化偏回归系数分别为0.679、-0.265,P分别为<0.01、0.029),但5分法 EFL 比 FEV_1对 MRC 呼吸困难评分的预测性更强。23例吸入沙丁胺醇前存在 EFL 患者,吸入后全部患者 EFL 仍然存在。结论与 FEV_1比较,EFL 对 COPD 患者呼吸困难严重程度预测性更强,可作为评价 COPD 患者呼吸困难严重程度更可靠的客观指标。COPD 患者的 EFL 不能被吸入支气管扩张剂逆转,即表现为 EFL 的不可逆性。     

Influence of ipratropiumbromide on heart rate and hemodynamics in patients with sinus bradycardia

In 13 patients with sinus bradycardia, heart rate and hemodynamics were recorded before and 3, 30, 60, and 120 minutes following intravenous administration of 0.5 mg ipratropiumbromide (Itrop by C. H. Boehringer Sohn, Ingelheim, West Germany). Heart rate already started to rise during the injection of ipratropiumbromide. It increased by an average of 78% three minutes following the administration as compared to pretreatment control values. Mean heart rate still was markedly increased by an average of 26% at 120 min following the injection of the drug. This effect of ipratropiumbromide on heart rate was accompanied by an increase in cardiac index while stroke volume decreased due to a decrease in ejection fraction and diastolic filling time.     

布地奈德联合沙丁胺醇雾化吸入对支气管哮喘急性发作的疗效观察

目的观察布地奈德联合沙丁胺醇雾化吸入对支气管哮喘急性发作的效果。方法80例患者随机分为两组,试验组40例予布地奈德联合沙丁胺醇雾化吸入,对照组40例仅予沙丁胺醇雾化吸入,观察用药前及治疗后15min、第3天和第7天症状改善。结果试验组治疗15min后心率、呼吸频率、治疗第3天、第7天症状评分均较治疗前明显改善（P〈0．05）。结论布地奈德联合沙丁胺醇雾化吸入对支气管哮喘急性发作治疗有效。