Hemodynamic resuscitation in septic shock requires aggressive fluid replacement and appropriate use of vasopressors to optimize arterial pressure (AP) and cardiac output (CO). Because responses to these drugs vary between patients and within patient over time, strict monitoring of patient condition and repetitive adjustment of drug dose are required. This task is time and labor consuming and is associated with poor adherence to resuscitation guidelines. To overcome this issue, we have developed a computer-controlled closed-loop drug infusion system for automated hemodynamic resuscitation in septic shock. Our system continuously computes arterial resistance (R) and stressed blood volume (V). Negative-feedback algorithm in the system controls R with noradrenaline (NA), and V with Ringer acetate solution (RiA), thereby controlling AP and CO. When our system was applied to dogs with septic shock, it automatically titrated the infusion of NA and RiA, controlled R and V, and restored AP and CO at target levels precisely (absolute % error < 6 %) over 4h-period. With use of this system, we also examined the effect of the use of short acting β -blocker, landiolol, on the initial hemodynamic resuscitation of septic shock. Use of the landiolol was associated with reduction in cardiac oxygen consumption and arterial lactate level without compromising the initial hemodynamic resuscitation. In this review, we introduce several previous closed-loop systems developed by other groups and our novel approach to control the hemodynamics in septic shock, and discuss the implications of these developments.
In recent times, patients with sepsis accompanied by disseminated intravascular coagulation （septic DIC ）, have a significantly high mortality rate. Many clinical trials have failed to prove the efficacy of antithrombotic therapy for septic DIC. This is partly because antithrombotic therapy could impair the host defense against bacterial invasion. It is difficult to distinguish physiological thrombosis formation from pathological ones in septic patients. This is due to a difficulty to discern when to begin antithrombotic therapy for pathological thrombosis. In addition, we do not have any guidelines for the adequate choice and duration of therapy.
Furthermore, several reports revealed that treatment strategy based on an early goal achievement for septic patients is similar in outcome with conventional therapy. Improvement of circulation is essential for DIC treatment because impaired circulation enhances tissue factor expression on the endothelial surface. However, hemodynamic parameters such as arterial blood pressure and central venous pressure are not enough for adequate management and follow-up.
Novel therapeutic regimens are needed in both antithrombotic and circulatory management.
Introduction: Diabetes mellitus (DM) is one of the well-known risk factors of postoperative stroke in cardiac surgery. Cerebrovascular CO2 reactivity and the changes in cerebral blood flow are impaired in diabetic patients. Regional cerebral oxygen saturation (rSO2) measured using near-infrared spectroscopy (NIRS) has been utilized in cardiac surgery to evaluate cerebral oxygenation. However, the difference of the rSO2 values between diabetic and non-diabetic patients during cardiopulmonary bypass (CPB) has not been well investigated. The aim of this study was to compare the rSO2values of diabetic and non-diabetic patients who underwent cardiac surgery. Methods: Thirty diabetic patients (DM group) and 30 age- and gender-matched non-diabetic patients (NDM [control] group) who underwent coronary artery bypass grafting (CABG), valve surgery, or both utilizing normothermic CPB were retrospectively investigated. The mean values of rSO2 at nine time points during the entire period of cardiac surgery were measured. Results: The rSO2 values in the DM group were significantly lower than those in the NDM group (p < 0.01) and the difference between the groups increased with the time after the initiation of CPB. Conclusions: The rSO2 values in diabetic patients are lower than those in non-diabetic patients during cardiac surgery with normothermic CPB. A further large prospective study will be needed to investigate the relationship between lower rSO2 values in diabetic patients and postoperative outcomes as well as the mechanism of the lower values.