Επίδραση συνεχούς φλεβοφλεβικής αιμοδιήθησης στην αιμοδυναμική και αναπνευστική λειτουργία, στην πρόγνωση καθώς και στην κινητική κυτταροκινών βαρειά σηπτικών ασθενών της ΜΕΘ

Abstract

Introduction Renal dysfunction and failure is a common consequence of the frequently encountered sepsis affecting critically ill patients. This is managed amongst others with the use of continuous renal replacement methods. This study was intended to explore the effects of CCRT beyond the established therapeutic benefits on the patients’ haemodynamics, organ dysfunction and cytokine kinetics of the SIRS that chracterise this multifacet syndrome. Questions that we set to answer in detail: Does CVVH influence cytokine kinetics for cytokines TNF-α, IL-6 and IL-1β ? How does it affect patient haemodynamics? How does it affect prognosis? We conducted 3 studies: A. Pilot study We measured clearance and concentrations of the cytokines under investigation in multiple blood and ultrafiltrate specimens and varying CVVH settings in 9 septic patients receiving renal replacement for acute renal failure. Results: We confirmed constantly high concentrations as well as brief bursts of cytokine production. The preferred circuit and flow for maximal clearance was set. B. Study no. 2 Hypothesis : Does CVVH improve haemodynamic and respiratory function? Method: 36 patients with severe sepsis were monitored for indices of haemodynamic and respiratory function while on CVVH. The filter was discontinued for 12 hrs for control within the cohort. Results: MAP, SVR and vasopressor requirements improved during CVVH with transient worsening during discontinuation. These differences were more pronounced in the group of patients that survived. C. Study no. 3 Hypothesis: Is the effected imroved haemodynamic status linked with imroved survival when applied as early as possible in patients with renal dysfunction? How does this affect cytokine kinetics? Methods: 30 consecutive patients with severe sepsis and/or septic shock were included in the study. CVVH was instituted as early as possible upon establishment of renal dysfunction. Clinical and laboratory indices of MOF were measured daily and plasma and ultrafiltrate specimens were taken and the investigated cytokines measured. Results: Of the measured indices MAP, SVR, CI as well as Pa02/Fi02 all improved during the course of the study, while in some of them there were also baseline differences (pre-CVVH) between survivors and non-survivors. Cytokine clearance and absorption on the membrane were quantified. Sieving coefficients were calculated for TNF- α and IL-6. A multivariate analysis of statistically significant differences between survivors and non-survivors revealed earlier institution of CVVH in the duration of the septic episode as the strongest predictor of survival.