Correlates of prolonged hospitalization in inner-city ICU patients receiving noninvasive and invasive positive pressure ventilation for status asthmaticus

STUDY OBJECTIVES: To describe the outcome of patients with status asthmaticus (SA) treated in a medical ICU with positive pressure ventilation (PPV), and to identify those factors associated with increased length of hospital stay. DESIGN: Retrospective chart review. SETTING: University-based hospital in Chicago, IL. PATIENTS: All patients admitted with SA and treated with PPV over a 5-year period. RESULTS: The first ICU admission for each of 78 patients was analyzed. Fifty-six patients underwent endotracheal intubation (ETI) during the hospitalization, while 22 patients were treated with noninvasive PPV alone. Three patients died. The median hospital length of stay was 5.5 days. Cox regression analysis revealed the following factors to be independently associated with increased length of hospital stay: female gender (p < 0.01), ETI (p < 0.01), the administration of neuromuscular blockers for > 24 h (p < 0.01), inhaled corticosteroid use prior to ICU admission (p = 0.01), and increasing APACHE (acute physiology and chronic health evaluation) II score (p < 0.01). CONCLUSIONS: This study suggests that while the mortality associated with SA treated with contemporary methods of PPV is low, certain factors, including female gender, ETI, and the prolonged use of neuromuscular blockade, are associated with an increased length of hospital stay. The development of respiratory failure despite preadmission use of inhaled corticosteroids is also associated with prolonged hospitalization.     

以肺部感染和氧合指数为控制窗在严重呼吸衰竭患者有创-无创序贯性机械通气中的应用比较

目的:比较以肺部感染和氧合指数(OI)为控制窗在严重呼吸衰竭患者有创-无创序贯性机械通气中的应用价值,为临床优化治疗提供参考。方法:采用随机平行对照法将78例慢性阻塞性肺疾病(COPD)致严重呼吸衰竭患者分为观察组和对照组,每组39例。2组均接受有创机械通气治疗,观察组患者行气管内插管后出现OI控制窗时,即刻拔除气管插管,改用口罩/鼻罩双水平正压通气序贯治疗;对照组患者行气管内插管后出现肺部感染控制窗时,即刻拔除气管插管并给予口罩/鼻罩双水平正压通气序贯治疗。密切观察2组患者的生命体征和症状,比较2组通气前、出窗时、通气后的心率(HR)、呼吸频率(RR)、动脉血氧分压(PaO_2)、平均动脉压(MAP)及OI指标变化,再插管、呼吸机相关性肺炎(VAP)及死亡的发生情况。记录患者出窗时间、总机械通气时间、住院时间及治疗费用。结果:2组通气前、出窗时HR、RR、PaO_2、MAP、OI监测值比较差异均无统计学意义(均P0.05),通气后上述指标较通气前均显著改善(均P0.05);其中观察组通气后RR较对照组显著降低,OI显著上升(均P0.05);观察组总机械通气时间短于对照组、住院治疗费用少于对照组(均P0.05);2组再插管率、病死率比较差异无统计学意义(均P0.05),观察组VAP发生率明显低于对照组(P0.05)。结论:肺部感染、OI均是临床呼吸衰竭患者行有创-无创序贯性机械通气的有效切换点标准,但OI指数在改善疗效、缩短住院时间、节约住院费用和降低VAP风险方面优于前者,可为临床制定机械通气策略提供参考。     

C-reactive protein and body mass index predict outcome in end-stage respiratory failure

STUDY OBJECTIVE: To determine the predictive factors of morbidity and mortality in patients with end-stage respiratory disease. DESIGN: Prospective, multicenter cohort study. SETTING: Thirteen outpatient chest clinics within the Association Nationale de Traitement à Domicile de l'Insuffisance Respiratoire. PARTICIPANTS: Stable adult patients with chronic respiratory failure receiving long-term oxygen therapy and/or home mechanical ventilation (n = 446; 182 women and 264 men; aged 68.5 +/- 12.1 years [+/- SD]); Respiratory diseases were COPD in 42.8%, restrictive disorders in 36.3%, mixed respiratory failure in 13.5%, and bronchiectasis in 7.4%. Recruitment was performed during the yearly examination. Patients with neuromuscular diseases and sleeping apnea were excluded. MEASUREMENTS AND RESULTS: Hospitalization days and survival were recorded during a follow-up of 14.3 +/- 5.6 months. Body mass index (BMI), serum albumin, and transthyretin levels were considered for their predictive value of outcome, together with demographic data, underlying respiratory disease, respiratory function, hemoglobin, C-reactive protein, smoking habits, oral corticosteroid use, and antibiotic treatment courses. Overall, 1.8 +/- 1.7 hospitalizations (cumulative stay, 17.6 +/- 27.1 days) were observed in 254 of 446 patients (57%). Independent predictors of hospitalization were oral corticosteroids, FEV(1), and plasma C-reactive protein. One-year and 2-year cumulative survivals were 93% and 69%, respectively. Plasma C-reactive protein, BMI, Pao(2) on room air, and oral corticosteroids independently predicted survival in multivariate analysis. CONCLUSION: Besides established prognosis factors such as FEV(1) and Pao(2), nutritional depletion as assessed by BMI and overall systemic inflammation as estimated by C-reactive protein appear as major determinants of hospitalization and death risks whatever the end-stage respiratory disease. BMI and C-reactive protein should be included in the monitoring of chronic respiratory failure. Oral corticosteroids as maintenance treatment in patients with end-stage respiratory disease are an independent risk factor of death, and should be avoided in most cases.     

糖皮质激素治疗严重急性呼吸综合征氧合指数的变化

目的 了解糖皮质激素在治疗SARS过程中对改善肺氧合功能的影响.方法 回顾性分析2003年SARS病例225例,氧合指数作为糖皮质激素疗效的判别指标,有效的标准是治疗后氧合指数较治疗前上升≥20%.采用方差分析、X2检验分析糖皮质激素的疗效.结果 225例中有134例(59.6%)SARS患者在治疗中使用糖皮质激素;所有患者糖皮质激素(静脉给药)治疗前氧合指数的平均水平为237.08 mm Hg.治疗后为335.08 mm Hg,平均升高110.26 mm Hg,升幅为46.4%;96例有血气分析结果的SARS患者中,符合应用指征的有85例(88.5%),糖皮质激素治疗后氧合指数平均升高103.14 mm Hg,升幅为44.4%,低于无应用指征的190.91 mm Hg,升幅为66.8%,两组差异无统计学意义;糖皮质激素治疗前后氧合指数差值随治疗前氧合指数水平升高而下降,治疗前氧合指数≥300 mm Hg组升高最少,升幅为5.6%.结论在SARS治疗中,适当应用糖皮质激素,对减轻患者肺部症状、改善肺功能有一定疗效,特别是对于符合急性肺损伤或急性呼吸窘迫综合征(ARDS)诊断、治疗前氧合指数水平较低患者(氧合指数＜300 mm Hg)的肺功能改善更明显.     

Avascular osteonecrosis after treatment of SARS: a 3-year longitudinal study

Objective  To investigate the relationship between avascular osteonecrosis (AVN) and corticosteroid treatment given to patients with severe acute respiratory syndrome (SARS).
Methods  Longitudinal study of 71 former SARS patients (mainly health care workers) who had been treated with corticosteroids, with an observation time of 36 months. Magnetic resonance images (MRI) and X-rays of hips, knees, shoulders, ankles and wrists were taken as part of the post-SARS follow-up assessments.
Results  Thirty-nine per cent developed AVN of the hips within 3–4 months after starting treatment. Two more cases of hip necrosis were seen after 1 year and another 11 cases of AVN were diagnosed after 3 years, one with hip necrosis and 10 with necrosis in other joints. In total, 58% of the cohort had developed AVN after 3 years of observation. The sole factor explaining AVN in the hip was the total dose of corticosteroids received.
Conclusion  The use of corticosteroids in SARS has been debated; opinions conflict about whether the immediate benefits in terms of saving lives compensate for the adverse effects, including AVN.     

Corticosteroids for acute chest syndrome in children with sickle cell disease: Variation in use and association with length of stay and readmission

Acute chest syndrome (ACS) causes significant morbidity and mortality in sickle cell disease. The role of corticosteroids is unclear. The objectives of our study were to examine the variation between hospitals in their use of corticosteroids for ACS, describe characteristics associated with corticosteroids, and investigate the association between corticosteroids, length of stay, and readmission. We performed a retrospective examination of 5,247 hospitalizations for ACS between January 1, 2004, and June 30, 2008, at 32 hospitals in the Pediatric Health Information System database. We used multivariate regression to examine the variability in the use of corticosteroids adjusting for hospital case mix, identify factors associated with corticosteroid use, and evaluate the association of corticosteroids with length of stay and 3‐day readmission rates controlling for propensity score. Corticosteroid use varied greatly by hospital (10–86% among all patients, 18–92% in patients with asthma). Treatment with corticosteroids was associated with comorbid asthma (OR 3.9, 95% CI: 3.2–4.8), inhaled steroids (OR 1.4, 95% CI: 1.1–1.7), bronchodilators (OR 3.2, 95% CI: 2.5–4.2), nitric oxide (OR 2.4, 95% CI: 1.2–5.0), oxygen (OR 2.3, 95% CI: 1.8–2.9), ICU (OR 1.7, 95% CI: 1.3–2.3), ventilation (OR 2.0, 95% CI: 1.4–2.8), APR‐DRG severity level (OR 1.4, 95% CI: 1.2–1.6), and discharge year (OR 0.86, 95% CI: 0.80–0.92). Corticosteroids were associated with an increased length of stay (25%, 95% CI: 14–38%) and a higher 3‐day readmission rate (OR 2.3, 95% CI: 1.6–3.4), adjusted for confounding. Hospitals vary greatly in the use of corticosteroids for ACS, even in patients with asthma. Clear evidence of the efficacy and toxicity of corticosteroid treatment in ACS may reduce variation in care. Am. J. Hematol. 2010. © 2009 Wiley‐Liss, Inc.     

Inhaled corticosteroids and the risk of mortality and readmission in elderly patients with chronic obstructive pulmonary disease

There is considerable controversy concerning the utility of inhaled corticosteroids for the long-term treatment of patients with COPD. Recent studies have suggested that although inhaled corticosteroids do not alter the rate of decline in lung function, they may reduce airway hyperresponsiveness, decrease the frequency of exacerbations, and slow the rate of decline in the patients' health status. The relationship between inhaled corticosteroids and subsequent risk of hospitalization or mortality remains unknown. We therefore conducted a population-based cohort study using administrative databases in Ontario, Canada (n = 22,620) to determine the association between inhaled corticosteroid therapy and the combined risk of repeat hospitalization and all-cause mortality in elderly patients with COPD. Patients who received inhaled corticosteroid therapy postdischarge (within 90 d) had 24% fewer repeat hospitalizations for COPD (95% confidence interval [CI], 22 to 35%) and were 29% less likely to experience mortality (95% CI, 22 to 35%) during 1 yr of follow-up after adjustment for various confounding factors. This cohort study has suggested that inhaled corticosteroid therapy is associated with reduced COPD-related morbidity and mortality in elderly patients. Although not definitive, because of the observational nature of these findings, these data provide a compelling rationale for a large randomized trial to determine the effect of inhaled corticosteroids on COPD-related morbidity and mortality.     

Effect of corticosteroids on adult varicella pneumonia: cohort study and literature review

BACKGROUND: Varicella pneumonia (VP) is a serious entity associated with morbidity and mortality. There have been sporadic reports using corticosteroids in life-threatening VP. We report a case series of VP to examine the outcome and the effect of corticosteroid use. METHODS: A retrospective chart review was conducted on all adult patients admitted to a tertiary care hospital with VP during a 14-year period. We documented oxygenation (SpO2, PaO2/FIO2) on admission and after 48 h, whether the patients were admitted to an intensive care unit (ICU), the use of mechanical ventilation, ICU and hospital length of stay (LOS) and patient outcome. We compared those patients who received corticosteroids with those who did not. RESULTS: We identified 19 patients with VP. Ten received corticosteroids, in addition to antiviral and supportive treatment. Patients who received corticosteroids were significantly more hypoxaemic on admission and all were admitted to ICU with seven of them intubated. Only two of the nine in non-steroid group were intubated. Despite their greater severity, the corticosteroid group showed a much more rapid improvement in oxygenation and a trend towards shorter duration of mechanical ventilation. The duration of ICU and hospital LOS were not significantly different. All patients survived. CONCLUSIONS: Corticosteroids in severe VP accelerate the physiological recovery and may shorten the duration of mechanical ventilation.     

Corticosteroid use in rheumatoid arthritis: prevalence, predictors, correlates, and outcomes

OBJECTIVE:To determine the rate of current and lifetime use of corticosteroids, the degree of association between corticosteroids and rheumatoid arthritis (RA) activity and outcome, corticosteroid initiation and discontinuation rates, and the predictors associated with initiation and discontinuation. METHODS: A total of 12,749 patients with RA were evaluated semiannually as to corticosteroid use, RA activity measures, RA outcomes, and predictors of initiation and discontinuation of corticosteroids. RESULTS: Current corticosteroid use was 35.5% and lifetime use was 65.5%. Rheumatologists varied substantially in their use of corticosteroids. The primary patient-derived determinant of corticosteroid initiation, current use, and discontinuation was symptom severity, although 21-25% of patients in remission or with minimal disease activity continued taking corticosteroids. Within the pool of current users, 24.3% [95% confidence interval (CI) 23.2-25.3%] discontinued corticosteroids yearly, and among patients newly starting corticosteroids this rate was 56.9% (95% CI 53.4-60.7%). Corticosteroid initiation occurred at a rate of 8.9% (95% CI 8.4-9.3%) per year. Among corticosteroid users, persistent use (> 5 years) occurs in about one-third of patients. Corticosteroid use and duration of use is associated with severe outcomes for current and past users. For current users versus non-current users, covariate adjusted outcomes were: mortality 5.7% versus 2.6%, work disability 28.4% versus 17.2%, and total joint replacement 18.5% versus 13.0%. CONCLUSION: Corticosteroid use is dynamic and is associated with RA severity. Corticosteroid use is also associated with adverse longterm outcomes, but the ability to discern causal associations is severely limited by confounding by indication. The idea of "once on corticosteroids, always on corticosteroids" is incorrect and applies to only a minority of patients.     

Efficacy of low-dose corticosteroids in patients with acute respiratory distress syndrome: a prospective observational study

BackgroundThere is still no agreement on whether corticosteroids can reduce mortality in patients with acute respiratory distress syndrome (ARDS). The aim of this study was to investigate the efficacy of low-dose corticosteroid administration in patients with ARDS.MethodsA prospective observational study of patients with ARDS in 17 hospitals in China was performed between March 2016 and February 2018. Propensity score matching was performed to adjust for differences in baseline characteristics between different groups. The effects of corticosteroids were assessed by using the Kaplan-Meier method and a multivariate Cox regression.ResultsA total of 527 ARDS patients were enrolled in the study. Sixty-five patients (12.3%) were administered low-dose (methylprednisolone ≤1 mg·kg⁻¹·d⁻¹) corticosteroids. The median dose was equivalent to 0.67 (0.57–0.81) mg/kg methylprednisolone for a median duration of 10 days. The control group included 224 patients (42.5%) who had never receive corticosteroids. In the matched sample, the hospital mortality rates in the low-dose (n=40) and control groups (n=80) were 27.5% and 42.5% (P=0.110), respectively. The length of hospital stay was significantly longer in the low-dose corticosteroid group than in the control group (24.0 vs. 17.0, P=0.002), and the multivariate Cox regression analysis suggested that the low-dose group had a significantly lower risk of death than the control group (HR: 0.48; 95% CI: 0.24–0.97; P=0.040).ConclusionsThe administration of low-dose corticosteroids may reduce mortality in patients with ARDS.     

Lupus pneumonitis or severe acute respiratory syndrome?

Severe acute respiratory syndrome (SARS) is a serious respiratory illness caused by a novel human coronavirus. The disease is highly infectious and carries significant mortality and morbidity. There was a major outbreak of SARS in Guangdong, Taiwan, Beijing, Hong Kong and Toronto between March and June 2003. Common presenting features of SARS are high fever, chills, rigor, malaise, nonproductive cough, lymphopenia and pulmonary infiltrates, followed by rapidly progressive respiratory failure in some cases. We describe two patients with systemic lupus erythematosus (SLE) who presented with fever, systemic upset and pulmonary infiltrates between April and June, 2003. One patient was confirmed to have coronavirus pneumonia while the other had active SLE with lung involvement. Our cases illustrate the difficult diagnostic dilemma in the evaluation of febrile SLE patients during the SARS epidemic.     

78例传染性非典型肺炎病例临床分析

目的　分析传染性非典型肺炎 (世界卫生组织又称严重急性呼吸综合征 ,SARS)患者的临床特点 ,并对其诊断标准和治疗方法进行探讨。方法　对广州呼吸疾病研究所 2 0 0 2年 12月 2 2日至 2 0 0 3年 3月 31日收治的 78例SARS患者的临床、实验室、影像学资料进行回顾性分析。结果78例SARS患者 :男 4 2例 ,女 36例 ;年龄 2 0～ 75岁 ,平均 (37 5± 11 6 )岁 ;医务人员 4 4例 (5 6 % )。临床症状包括 :发热 (10 0 % )、咽痛 (17% )、咳嗽 (88% )、气促 (80 % )、畏寒 (5 9% )、肌肉酸痛 (41% )。血常规 :白细胞 (WBC) <4 0× 10 9/L 12例 (15 % ) ,WBC(4 0～ 10 0 )× 10 9/L 4 9例 (6 3% ) ,WBC >10 0× 10 9/L 17例 (2 2 % ) ,平均为 (7 6± 5 0 )× 10 9/L ;中性粒细胞为 0 75± 0 14 ,淋巴细胞 0 18±0 11。胸部X线和CT显示肺部斑片状阴影 ,短期内病灶增多 ,累计单侧 2 3例 (30 % )、双侧 5 2例(6 7% )。分析医护人员被感染途径 ,提示本病具有较强的飞沫近距离传染特性。出现急性肺损伤(ALI) 37例 (47% ) ,其中发展为急性呼吸窘迫综合征 (ARDS) 2 1例。 7例死亡患者均为ARDS合并有多器官功能衰竭综合征 (MODS)。结论　流行病接触史、发热、X线肺炎征及白细胞计数正常或减少是诊断本病的临床依据。     

重症急性呼吸综合征患者中重症者早期预警指标研究

目的　探讨重症急性呼吸综合征 (SARS)患者中与重症发生相关的危险因素 ,寻找发生重症的早期预警指标。方法　对北京市SARS临床诊断病例数据库中转院资料完整 ,且在 2周内发生重症的 35 5例和始终未发生重症的 84 1例SARS患者进行单因素和多因素分析。结果　高龄、有基础病的患者发生重症的危险性明显增加。重症患者发生重症前表现出以下特点 :体温下降缓慢、脉搏加快、淋巴细胞计数持续 <0 9× 10 9/L、中性粒细胞高于 7 1× 10 9/L(80 % )、X线胸片异常进展较快等。采用Cox多元逐步回归发现 ,具有统计学显著性的早期预警重症发生的独立因素包括 :年龄偏大、有基础疾病、住院 2d后体温仍不能降至正常、住院 3d后中性粒细胞比值持续在 80 %以上、住院 4d后淋巴细胞计数仍持续 <0 9× 10 9/L和病程中出现脉搏持续加快达到 10 0次 /min。结论　根据SARS患者的年龄和基础病情况 ,结合临床对体温、脉搏、淋巴细胞绝对值以及中性粒细胞绝对值 (百分比 )的密切观察能够对重症SARS的发生进行早期预警。     

Impact of regular inhaled corticosteroid use on chronic obstructive pulmonary disease outcomes

Inhaled corticosteroids are often used to manage chronic obstructive pulmonary disease, although the evidence regarding their long-term efficacy in preventing or reducing adverse health outcomes is not definitive. This retrospective cohort study analyzed whether regular inhaled corticosteroid use is associated with reduced health care utilization and all-cause mortality related to chronic obstructive pulmonary disease. Subjects were 2,902 health maintenance organization members aged 50 and over who met criteria for chronic obstructive pulmonary disease. The study used a composite endpoint of time to (1) death or (2) hospitalization or emergency room care related to chronic obstructive pulmonary disease, whichever occurred first, during a 4-year follow-up. Among the 42% of chronic obstructive pulmonary disease patients with an indication of co-morbid asthma, inhaled corticosteroid use was associated with significantly reduced risk for both all-cause mortality and the composite outcome. The reduction in risk was greatest in never- and ex-smokers. Among chronic obstructive pulmonary disease patients with no indication of asthma, inhaled corticosteroid use was associated with reduced risk only in never smokers. These findings generally persisted in separate analyses stratified by asthma status and in sensitivity analyses using four alternative definitions of regular medication use, with comparable results when regular medication use was treated as a fixed covariate defined at the start of follow-up. We conclude that use of inhaled corticosteroids was associated with reduced risk of chronic obstructive pulmonary disease exacerbations and all-cause mortality. This benefit was most pronounced among never-smokers and in those with evidence of co-morbid asthma.     

重症传染性非典型肺炎的治疗及死亡危险因素的分析

目的　探讨重症传染性非典型肺炎 (世界卫生组织又称严重急性呼吸综合征 ,SARS)的治疗方法以及预测死亡的可能危险因素。方法以 2 0 0 2年 12月至 2 0 0 3年 3月临床诊断重症SARS37例患者为对象 ,通过回顾性分析 ,比较 33例应用持续气道内正压的方式进行无创通气前后的呼吸频率和脉搏容积血氧饱和度 (SpO2 ) ,并对其中 18例吸氧 5L/min、安静下SpO2 只有 90 %～ 93%的患者 ,进行无创通气前轻微活动、安静状态及无创通气 1h后SpO2 的比较 ;对年龄、基础疾病、血小板减少、白细胞升高、淋巴细胞减少 5个因素预测死亡的可能危险性采用Mantel Haenszelχ2 检验进行统计学分析。结果　 33例患者无创通气 1h后较通气前呼吸频率明显减慢 (P <0 0 1) ,分别为 (2 9 6±10 0 )次 /min和 (34 6± 8 4 )次 /min ;SpO2 明显提高 (P <0 0 1) ,分别为 (96 1± 2 4 ) %和 (89 9±3 5 ) %。 18例吸氧 5L/min、安静下SpO2 只有 90 %～ 93%的患者 ,轻微活动后SpO2 明显下降 ,无创通气 1h后SpO2 明显提高 ,SpO2 分别为 (91 7± 0 9) %、(88 5± 1 4 ) %和 (96 9± 1 8) % (P均 <0 0 1) ;以血小板减少、年龄 >5 0岁、基础疾病、血白细胞升高、淋巴细胞减少 5个因素预测死亡的可能危险性 ,其相对危险度 (RR )分别为 2     

Contemporary management of acute exacerbations of COPD: a systematic review and metaanalysis

BACKGROUND: Systemic corticosteroids, antibiotics, and noninvasive positive pressure ventilation (NPPV) are recommended for patients with acute exacerbation of COPD. However, their clinical benefits in various settings are uncertain. We undertook a systematic review and metaanalysis to systematically evaluate the effectiveness of these therapies. METHODS: MEDLINE and EMBASE were searched to identify relevant randomized controlled clinical trials published from January 1968 to November 2006. We identified additional studies by searching bibliographies of retrieved articles. RESULTS: Compared with placebo, systemic corticosteroids reduced treatment failure by 46% (95% confidence interval [CI], 0.41 to 0.71), length of hospital stay by 1.4 days (95% CI, 0.7 to 2.2), and improved FEV(1) by 0.13 L after 3 days of therapy (95% CI, 0.04 to 0.21). Meanwhile, the risk of hyperglycemia significantly increased (relative risk, 5.88; 95% CI, 2.40 to 14.41). Compared with placebo, antibiotics reduced treatment failure by 46% (95% CI, 0.32 to 0.92) and in-hospital mortality by 78% (95% CI, 0.08 to 0.62). Compared with standard therapy, NPPV reduced the risk of intubation by 65% (95% CI, 0.26 to 0.47), in-hospital mortality by 55% (95% CI, 0.30 to 0.66), and the length of hospitalization by 1.9 days (95% CI, 0.0 to 3.9). CONCLUSIONS: For acute COPD exacerbations, systemic corticosteroids are effective in reducing treatment failures, while antibiotics reduce mortality and treatment failures in those requiring hospitalization and NPPV reduces the risk of intubation and in-hospital mortality, especially in those who demonstrate respiratory acidosis.     

SARS: pharmacotherapy

The pharmacotherapy for severe acute respiratory syndrome (SARS) is controversial and largely anecdotal. Most patients with suspected SARS should initially be treated with potent antibiotics before proceeding to 'anti-SARS' therapy. There is a spectrum of severity and rate of progression in SARS, and the stages of viral replication, inflammatory pneumonitis and residual pulmonary fibrosis are clinically non-distinct. Although now considered lacking in efficacy, ribavirin was used extensively in Hong Kong for treatment of SARS. Retrospective data suggest that the use of Kaletra (ritonavir and lopinavir), an anti-protease, could reduce mortality and improve outcomes, although the adverse reactions are also worrisome. Anecdotal experience strongly supports the use of steroid, at least in a subset of SARS patients, particularly with 'critical SARS' who display continued clinical instability or deterioration and progressive radiographic or HRCT deterioration. A retrospective study carried out of 72 probable SARS patients has shown that cases who received pulse methylprendisolone did not differ in cumulative steroid dosage or adverse reactions, although the former patients had less oxygen requirement, better radiographic outcome, and less likelihood of requiring rescue pulse steroid therapy than their counterparts. Nevertheless, lower dosage of steroid as initial therapy in SARS had also been associated with good clinical outcomes. Poor responders to initial therapy might benefit from rescue steroid therapy or intravenous Pentaglobin. Other drug treatments had also been tried in desperate patients, including the use of convalescence serum and plasmapheresis. Secondary infections could be troublesome, particular for patients with prolonged hospitalization and mechanical ventilation.     

Effectiveness of inhaled corticosteroids in chronic obstructive pulmonary disease: immortal time bias in observational studies

Recent large-scale cohort studies that reported an important reduction in mortality and chronic obstructive pulmonary disease (COPD) morbidity with inhaled corticosteroids may be biased. We used a population-based cohort of Saskatchewan residents 55 years of age or over, first hospitalized for COPD during 1990 to 1997, to study this potential bias. These 979 subjects were followed for a year from discharge until their first readmission for COPD or death (389 subjects). Inhaled corticosteroid exposure was measured as any dispensing within 90 days after discharge. Cox's proportional hazards model was used to compare the time-fixed analysis employed in the recent studies with the alternative time-dependent analysis. The time-fixed adjusted rate ratio was 0.69 (95% CI: 0.55-0.86) for inhaled corticosteroid use within 90 days, whereas the time-dependent rate ratio was 1.00 (95% CI: 0.79-1.26). With the time-fixed analysis, the rate ratios were affected by the length of the exposure period, decreasing from 0.98 for a 15-day exposure period to 0.51 for 365 days, but remained stable between 1.06 and 0.94 with the time-dependent analysis. Inhaled corticosteroid use after hospitalization for COPD was not found to reduce mortality and morbidity. Although observational studies can be valuable, the recent reports of reductions in mortality and morbidity with inhaled corticosteroids are biased by their inappropriate allocation of exposure and analysis of immortal time.     

严重急性呼吸综合征康复者股骨近端骨髓的磁共振成像研究

目的了解糖皮质激素(简称激素)使用及严重急性呼吸综合征(SARS)感染本身对SARS康复者股骨骨髓转换的影响。方法观察148例SARS[42例未用激素(未用激素组)、106例使用激素(使用激素组)]康复医务人员及97名年龄与性别匹配的正常对照者(正常对照组)磁共振成像(MR I)上股骨近端骨髓的分布,并在T1加权成像上测量并比较未用激素组、使用激素组的SARS康复者及正常对照组之间骨髓转换指数的差异。结果148例中106例使用激素的SARS康复者,4例出现股骨头缺血坏死,2例股骨骨髓水肿,1例股骨颈骨梗死。正常对照组、未用激素组及使用激素组SARS康复者骨髓转换指数分别为(79.4±6.8)%、(86.9±7.4)%、(88.6±5.9)%,使用激素组与未用激素组、使用激素组与正常对照组、未用激素组与正常对照组的比较,P值分别为<0.05、<0.01、<0.01,差异均有统计学意义。结论激素的应用可促进股骨近端骨髓黄骨髓化,而SARS感染本身也可导致股骨颈红骨髓过度转换为黄骨髓。