Abstract and Introduction
Aim: Low serum albumin levels occur in a variety of disease states and are related to in-hospital mortality and length of stay. The purpose of this study was to evaluate the association of commonly measured biochemical markers in critically ill patients such as serum albumin or C-reactive protein (CRP) with the need for intensive respiratory or vasopressor support (IRVS) in patients with 2009 influenza A (H1N1).
Methods: A total of 104 patients from an H1N1 registry database of 2436 patients were enrolled. Clinical characteristics and laboratory findings within 24 h of admission were reviewed to evaluate whether serum biochemical markers can be used as predictors of illness severity in adult patients with H1N1 based on the need for IRVS.
Results: Twenty-four (23.1%) of the 104 patients enrolled in the study received IRVS during the study period. Independent predictors of the need IRVS were serum glucose level on admission (OR 1.02; 95% CI 1.00–1.04; p = 0.021) and serum albumin level on admission (OR 0.12; 95% CI 0.02–0.63; p = 0.013). The diagnostic sensitivity of albumin levels for predicting the need for IRVS in patients with confirmed H1N1 with a cut-off value of 2.7 g/dl was 79.17% (95% CI 57.8–92.9), the specificity was 85.71% (95% CI 75.9–92.6), the positive predictive value was 63.3% (95% CI 43.9–80.1) and the negative predictive value was 93.0% (95% CI 84.3–97.7). The area under the receiver operation characteristic curve was 0.860 (95% CI 0.773–0.923) for albumin, 0.808 (95% CI 0.713–0.882) for glucose and 0.734 (95% CI 0.633–0.821) for CRP.
Conclusions: Serum albumin levels and glucose levels on admission were predictors of the need IRVS in adult patients with H1N1. Based on these findings, the level of albumin at presentation may serve as a novel and simple early biomarker to identify patients at high risk for a complicated clinical course of disease.
The clinical outcomes of 2009 influenza A (H1N1) virus (H1N1) infection varied from mild to severe cases. The most frequent clinical syndrome leading to hospitalisation was pneumonia, which was associated with severe hypoxemia, acute respiratory distress syndrome and occasionally shock and renal failure. Many patients with H1N1 infection who were hospitalised or died had no documented underlying medical conditions. However, coexisting conditions connected to complications of seasonal influenza were risk factors for complications of H1N1. Pregnant women, those who were less than 2 weeks postpartum, and patients who were immunosuppressed or had neurologic disorders were overrepresented among those with severe H1N1. Severe obesity, as well as obesity-associated risks such as cardiovascular disease and diabetes, has also been identified as risk factors for severe complications of H1N1.
Several biochemical markers are associated with the severity of influenza infection, including cytokines such as interleukin-6 (IL-6), C-reactive protein (CRP) and procalcitonin. Serum albumin is also a commonly tested biomarker in hospitalised patients. Low serum albumin levels occur in a variety of disease states and are related to in-hospital mortality and length of stay. They have been proposed as a reliable predictor of outcomes in critically ill patients with infectious diseases.
The objective of this study is to evaluate the association of biochemical markers such as CRP and albumin with disease severity in adult patients with H1N1. The ability to predict which patients will require ICU admission can be difficult because clinicians appear to rely on their own clinical judgement to estimate illness severity. Therefore, we assessed the severity of influenza specifically associated with the use of intensive respiratory or vasopressor support (IRVS) because this is likely to be an objective marker of influenza severity across institutions and healthcare systems. Consequently, the relationship between serum biomarkers such as albumin and CRP and the need for IRVS in patients with H1N1 was investigated.