Multivariate regression modeling for the prediction of inflammation, systemic pressure, and end-organ function in...

The purpose of this study was to evaluate the feasibility of developing multivariate equations that predicted blood pressure and measured levels of end-organ function indicators quantitatively up to 72 h in advance in critically ill patients with severe sepsis. Data collected prospectively from 59 patients entered into two sequential placebo-controlled clinical trials of recombinant interleukin-1 receptor antagonist in severe sepsis and septic shock was analyzed retrospectively. A series of multivariate equations were developed to predict systemic pressure, coagulation, and vital organ function indicators quantitatively at 24, 48, and 72 h after the onset of severe sepsis. These equations used physiologic and clinical laboratory measurements, plus circulating levels of eicosanoids and cytokines obtained when severe sepsis criteria first were met, and end-organ function indicators measured 24, 48, and 72 h later. Multivariate predictive equations were developed for temperature, white blood cell count, mean arterial pressure (MAP), Pao2/FiO2 ratio, the Murray acute lung injury score, alanine and aspartate aminotransferases, prothrombin time, partial thromboplastin time, platelet count, serum creatinine, and Glasgow Coma Scale. The percentage of data variation explained by the equations ranged from 11.4% (MAP at 48 h) to 85.1% (platelet count at 24 h). Linear regression analysis of predicted values, obtained by entering baseline data from individual patients into the multivariate equations, versus observed results at 24, 48, and 72 h yielded regression coefficients ranging from .371 (MAP at 48 h) to .924 (platelet count at 24 h). Among patients without end-organ dysfunction at baseline, sensitivities for predicting values consistent with the onset of organ failure were > or = 88% in 21/27 (78%) of the predictive equations. Resolution of organ failure indicators present at baseline was predicted successfully in individual patients, with 20/27 (74%) specificities > or = 76%. In critically ill patients with severe sepsis, multivariate analysis of interactions among clinical observations, standard laboratory tests, and inflammatory response mediators produced equations that predicted systemic blood pressure and inflammatory and end-organ function indicators quantitatively up to 72 h in advance. Whether or not this methodology might be developed further to predict subclinically the onset and resolution of acute organ failure and shock in critically ill patients, and if it can be validated in a prospective trial will require further studies.