Rita Linko

Effectiveness of neuraminidase inhibitors in reducing mortality in patients admitted to hospital with influenza A H1N1pdm09 virus infection: a meta-analysis of individual participant data

BACKGROUND Neuraminidase inhibitors were widely used during the 2009-10 influenza A H1N1 pandemic, but evidence for their effectiveness in reducing mortality is uncertain. We did a meta-analysis of individual participant data to investigate the association between use of neuraminidase inhibitors and mortality in patients admitted to hospital with pandemic influenza A H1N1pdm09 virus infection. METHODS We assembled data for patients (all ages) admitted to hospital worldwide with laboratory confirmed or clinically diagnosed pandemic influenza A H1N1pdm09 virus infection. We identified potential data contributors from an earlier systematic review of reported studies addressing the same research question. In our systematic review, eligible studies were done between March 1, 2009 (Mexico), or April 1, 2009 (rest of the world), until the WHO declaration of the end of the pandemic (Aug 10, 2010); however, we continued to receive data up to March 14, 2011, from ongoing studies. We did a meta-analysis of individual participant data to assess the association between neuraminidase inhibitor treatment and mortality (primary outcome), adjusting for both treatment propensity and potential confounders, using generalised linear mixed modelling. We assessed the association with time to treatment using time-dependent Cox regression shared frailty modelling. FINDINGS We included data for 29,234 patients from 78 studies of patients admitted to hospital between Jan 2, 2009, and March 14, 2011. Compared with no treatment, neuraminidase inhibitor treatment (irrespective of timing) was associated with a reduction in mortality risk (adjusted odds ratio [OR] 0·81; 95% CI 0·70-0·93; p=0·0024). Compared with later treatment, early treatment (within 2 days of symptom onset) was associated with a reduction in mortality risk (adjusted OR 0·48; 95% CI 0·41-0·56; p<0·0001). Early treatment versus no treatment was also associated with a reduction in mortality (adjusted OR 0·50; 95% CI 0·37-0·67; p<0·0001). These associations with reduced mortality risk were less pronounced and not significant in children. There was an increase in the mortality hazard rate with each days delay in initiation of treatment up to day 5 as compared with treatment initiated within 2 days of symptom onset (adjusted hazard ratio [HR 1·23] [95% CI 1·18-1·28]; p<0·0001 for the increasing HR with each days delay). INTERPRETATION We advocate early instigation of neuraminidase inhibitor treatment in adults admitted to hospital with suspected or proven influenza infection. FUNDING F Hoffmann-La Roche.

Lung-Protective Ventilation With Low Tidal Volumes and the Occurrence of Pulmonary Complications in Patients Without Acute Respiratory Distress Syndrome: A Systematic Review and Individual Patient Data Analysis.

Objective:Protective mechanical ventilation with low tidal volumes is standard of care for patients with acute respiratory distress syndrome. The aim of this individual patient data analysis was to determine the association between tidal volume and the occurrence of pulmonary complications in ICU patients without acute respiratory distress syndrome and the association between occurrence of pulmonary complications and outcome in these patients. Design:Individual patient data analysis. Patients:ICU patients not fulfilling the consensus criteria for acute respiratory distress syndrome at the onset of ventilation. Interventions:Mechanical ventilation with low tidal volume. Measurements and Main Results:The primary endpoint was development of a composite of acute respiratory distress syndrome and pneumonia during hospital stay. Based on the tertiles of tidal volume size in the first 2 days of ventilation, patients were assigned to a “low tidal volume group” (tidal volumes⩽ 7 mL/kg predicted body weight), an “intermediate tidal volume group” (> 7 and < 10 mL/kg predicted body weight), and a “high tidal volume group” (≥ 10 mL/kg predicted body weight). Seven investigations (2,184 patients) were included. Acute respiratory distress syndrome or pneumonia occurred in 23% of patients in the low tidal volume group, in 28% of patients in the intermediate tidal volume group, and in 31% of the patients in the high tidal volume group (adjusted odds ratio [low vs high tidal volume group], 0.72; 95% CI, 0.52–0.98; p = 0.042). Occurrence of pulmonary complications was associated with a lower number of ICU-free and hospital-free days and alive at day 28 (10.0 ± 10.9 vs 13.8 ± 11.6 d; p < 0.01 and 6.1 ± 8.1 vs 8.9 ± 9.4 d; p < 0.01) and an increased hospital mortality (49.5% vs 35.6%; p < 0.01). Conclusions:Ventilation with low tidal volumes is associated with a lower risk of development of pulmonary complications in patients without acute respiratory distress syndrome.

One-year mortality, quality of life and predicted life-time cost-utility in critically ill patients with acute respiratory failure

IntroductionHigh daily intensive care unit (ICU) costs are associated with the use of mechanical ventilation (MV) to treat acute respiratory failure (ARF), and assessment of quality of life (QOL) after critical illness and cost-effectiveness analyses are warranted.MethodsNationwide, prospective multicentre observational study in 25 Finnish ICUs. During an eight-week study period 958 consecutive adult ICU patients were treated with ventilatory support over 6 hours. Of those 958, 619 (64.6%) survived one year, of whom 288 (46.5%) answered the quality of life questionnaire (EQ-5D). We calculated EQ-5D index and predicted lifetime quality-adjusted life years (QALYs) gained using the age- and sex-matched life expectancy for survivors after one year. For expired patients the exact lifetime was used. We divided all hospital costs for all ARF patients by the number of hospital survivors, and by all predicted lifetime QALYs. We also adjusted for those who died before one year and for those with missing QOL to be able to estimate the total QALYs.ResultsOne-year mortality was 35% (95% CI 32 to 38%). For the 288 respondents median [IQR] EQ-5D index after one year was lower than that of the age- and sex-matched general population 0.70 [0.45 to 0.89] vs. 0.84 [0.81 to 0.88]. For these 288, the mean (SD) predicted lifetime QALYs was 15.4 (13.3). After adjustment for missing QOL the mean predicted lifetime (SD) QALYs was 11.3 (13.0) for all the 958 ARF patients. The mean estimated costs were 20.739 € per hospital survivor, and mean predicted lifetime cost-utility for all ARF patients was 1391 € per QALY.ConclusionsDespite lower health-related QOL compared to reference values, our result suggests that cost per hospital survivor and lifetime cost-utility remain reasonable regardless of age, disease severity, and type or duration of ventilation support in patients with ARF.

Corticosteroid therapy in intensive care unit patients with PCR-confirmed influenza A(H1N1) infection in Finland

To evaluate the incidence, treatment, and outcome of influenza A(H1N1) in Finnish intensive care units (ICUs) with special reference to corticosteroid treatment.

Serum zinc in critically ill adult patients with acute respiratory failure.

Background and aims: Zinc deficiency leads to susceptibility to infections and may affect pulmonary epithelial cell integrity. Low zinc levels have also been associated with a degree of organ failure and decreased survival in critically ill children. Accordingly, the purpose of the study was to assess serum zinc in adult patients with acute respiratory failure, its association with ventilatory support time, intensive care unit (ICU) length of stay (LOS), organ dysfunction and 30‐day mortality.

Serum activin A and B, and follistatin in critically ill patients with influenza A(H1N1) infection

BackgroundActivin A and its binding protein follistatin (FS) are increased in inflammatory disorders and sepsis. Overexpression of activin A in the lung causes similar histopathological changes as acute respiratory distress syndrome (ARDS). ARDS and severe respiratory failure are complications of influenza A(H1N1) infection. Interleukin 6 (IL-6), which in experimental studies increases after activin A release, is known to be related to the severity of H1N1 infection. Our aim was to evaluate the levels of activin A, activin B, FS, IL-6 and IL-10 and their association with the severity of respiratory failure in critically ill H1N1 patients.MethodsA substudy of a prospective, observational cohort of H1N1 patients in Finnish intensive care units (ICU). Clinical information was recorded during ICU treatment, and serum activin A, activin B, FS, IL-6 and IL-10 were measured at admission to ICU and on days 2 and 7.ResultsBlood samples from 29 patients were analysed. At the time of admission to intensive care unit, elevated serum levels above the normal range for respective age group and sex were observed in 44% for activin A, 57% for activin B, and 39% for FS. In 13 of the 29 patients, serial samples at all time points were available and in these the highest activin A, activin B and FS were above the normal range in 85%, 100% and 46% of the patients, respectively. No difference in baseline or highest activin A or activin B was found in patients with or without acute lung injury (ALI) or ARDS (P > 0.05 for all). Peak levels of IL-6 were significantly elevated in ALI/ARDS patients. Peak activin A and activin A/FS were associated with ventilatory support free-days, severity of acute illness and length of ICU stay (P < 0.05 for all).ConclusionsHigher than normal values of these proteins were common in patients with H1N1 infection but we found no association with the severity of their respiratory failure.

Serum MMP-8 and TIMP-1 in critically ill patients with acute respiratory failure: TIMP-1 is associated with increased 90-day mortality.

BACKGROUND:Matrix metalloproteinases (MMPs) likely have an important role in the pathophysiology of acute lung injury. In a recent study, high matrix metalloproteinases (MMP-8) levels in tracheal aspirates of pediatric acute respiratory distress syndrome (ARDS) patients were associated with worse outcome. In patients with sepsis, an imbalance between MMPs and their tissue inhibitors (TIMPs) has been associated with impaired survival. We hypothesized that the elevated systemic MMP-8 and TIMP-1 are associated with worse outcome in acute respiratory failure. METHODS:This was a substudy of the observational FINNALI study conducted in 25 Finnish intensive care units over an 8-week period. All patients older than 16 years requiring mechanical ventilation for >6 hours were included. MMP-8 and TIMP-1 levels were analyzed from blood samples taken on enrollment in the study and 48 hours later. Laboratory analyses were performed by using immunofluorometric assay for MMP-8 and ELISA for TIMP-1. MMP-8 and TIMP-1 levels were compared between 90-day survivors and nonsurvivors. Survival was compared in quartiles based on TIMP-1 levels, and ROC analysis was performed to calculate areas under the curves. The relationship between MMP-8 and TIMP-1 levels and degree of hypoxemia was examined. RESULTS:The final analyses included 563 patients. Admission TIMP-1 levels were higher in nonsurvivors, median 367 ng/mL (interquartile range 199–562), than survivors, median 240 ng/mL (interquartile range 142–412), WMWodds 1.68 (95% confidence interval [CI], 1.43–2.08). MMP-8 levels may have differed between survivors and nonsurvivors, WMWodds 1.20 (95% CI, 1.01–1.43), but no difference was found in the MMP-8/TIMP-1 molar ratio, WMWodds 0.83 (95% CI, 0.67–1.04). Difference in survival between quartiles based on TIMP-1 was significant (log-rank, P < 0.001). ROC analysis produced an area under the curve 0.63 (95% CI, 0.58–0.69) for TIMP-1. TIMP-1 was associated with severity of hypoxemia. TIMP-1 levels were higher in an ARDS subgroup than in the whole cohort, WMWodds 1.65 (95% CI, 1.15–2.44). CONCLUSIONS:MMP-8 levels were possibly higher in 90-day nonsurvivors but performed poorly in predicting outcome. Increased systemic levels of TIMP-1 were associated with more severe hypoxemia and worse outcome in a large cohort of mechanically ventilated critically ill patients and in a subgroup of ARDS patients.

Impact of neuraminidase inhibitors on influenza A(H1N1)pdm09‐related pneumonia: an individual participant data meta‐analysis

The impact of neuraminidase inhibitors (NAIs) on influenza‐related pneumonia (IRP) is not established. Our objective was to investigate the association between NAI treatment and IRP incidence and outcomes in patients hospitalised with A(H1N1)pdm09 virus infection.

N-terminal-pro-BNP in critically ill patients with acute respiratory failure: a prospective cohort study.

Background: The aim of this study was to evaluate the prognostic value of plasma N‐terminal pro‐B‐type natriuretic peptide (NT‐pro‐BNP) in unselected critically ill patients with acute respiratory failure (ARF).

Plasma neutrophil gelatinase-associated lipocalin and adverse outcome in critically ill patients with ventilatory support

Plasma neutrophil gelatinase‐associated lipocalin (pNGAL) has been introduced as an early and sensitive biomarker of acute kidney injury (AKI), with an increased risk for renal replacement therapy (RRT) and adverse outcome in selected critically ill patient groups. Acute respiratory failure is the most common organ dysfunction in critically ill patients with an increased risk for AKI. Accordingly, we hypothesized that pNGAL would independently predict adverse outcome in a heterogeneous group of critically ill adult patients with acute respiratory failure.