Dinko Tonković

CVP vs. dynamic hemodynamic parameters as preload indicators in hemodynamically unstable patients after major surgery

Introduction. Adequate circulating blood volume is essential for the good outcome in postoperative patients. Therefore, the primary resuscitation question is how to assess the circulating volume. The aim of this study was to compare the central venous pressure (CVP) and dynamic LIDCO parameters as markers indicating preload in surgical patients. Materials and Methods. This prospective study included 24 patients hospitalized after major surgery at the surgical intensive care unit of the University hospital Zagreb, Croatia. The patients were mechanically ventilated, without spontaneous breathing attempts and in sinus rhythm. Patients were divided into 2 groups, hemodynamically stable and hemodynamically unstable. The CVP was measured as a static parameter while the stroke volume variation (SVV) and pulse pressure variation (PPV) were measured as the dynamic parameters. Results. Study groups were comparable in terms of gender, age and body mass index. The difference in the CVP between the hemodynamically stable (13,2±3,74 mmHg) and hemodynamically unstable group of patients (10,1±5,6 mmHg) was statistically insignificant (p=0,144). Differences in SVV (10,2±6,48% in stable compared to 18,8±7,04% in unstable group) and PPV (11,5±6,65% in stable compared to 18±6,32% in unstable group) were both statistically significant with p values of 0,005 and 0,022 respectively. Conclusion. The study confirmed the inability of CVP to provide valid assessment of the preload as a reason for hemodynamic instability in comparison to dynamic LiDCOTMplus system parameters in mechanically ventilated major surgical patients.

Indications for blood transfusions in critical illness

Transfusion of blood products should improve tissue oxygenation and reduce negative consequences of anaemia. At the same time, adverse effects of transfusion, such as infections, immunologic reactions and mistransfusion, could be deleterious. Most transfusion guidelines suggest look-ing at the combination of haemoglobin or haematocrit levels in addition to clinical signs in the decision making process for a blood transfusion. The problem with such indications is that the clinical evaluation may be misleading in severely ill patients and haemoglobin levels that impair oxy-gen delivery cannot be determined easily. Many studies attempted to establish more convenient parameters, such as oxygen saturation from mixed and central ve-nous blood, tissue oxygen extraction and other methods. Although the results from these studies are conflicting, it appears that global oxygenation parameters are a good indicator for a blood transfusion in some categories of critically ill patients.

Extravascular lung water index as an indicator of lung injury in septic patients

Introduction. Transpulmonary thermodilution using PiCCO (Pulse-induced Contour Cardiac Output) is a standard minimally invasive method used for haemodynamic monitoring. Objectives. The goal of this paper is to examine the correlation and dynamics of the ExtraVascular Lung Water Index (EVLWI) as an indicator of acute lung injury in septic patients who underwent major abdominal surgery. Two groups of patients were selected: the ones with ALI (Acute Lung Injury): ALI patient group, and the ones without ALI: non-ALI patient group. A correlation between EVLWI and other haemodynamic and respiratory data in both groups were analyzed.Materials and methods. The study included 48 patients. Throughout the seven-day period EVLWI, GEDVI (Global End-Diastolic Volume Index), ITBVI (IntraThoracic Blood Volume Index), CI (Cardiac Index), SVRI (Systemic Vascular Resistance Index) were measured in both groups using PiCCO monitoring over 8-hour intervals as well as heart rate, mean arterial pressure, serum albumin concentration, PaCO2 (arterial partial pressure of carbon dioxide), PaO2 (arterial partial pressure of oxygen), PaO2/FiO2 (arterial partial pressure of oxygen/fraction of inspired oxygen) ratio, lung compliance, lung resistance and ScvO2 (central venous oxygen saturation). All patients were analgosedated, intubated, mechanically ventilated, in sinus cardiac rhythm. Circulatory unstable patients had vasoactive support and Sequential Organ Failure Assessment (SOFA) scores calculated. Ventilator settings and dosage of vasoactive drugs were kept constant during the study.Results. EVLWI was significantly higher in ALI patients group compared to non-ALI patients group. In patients with ALI group 11/22 patients died (50%), in the non-ALI patients group 6/26 patients died (23%). EVLWI was significantly higher in patients that died compared to ones who survived.Conclusion. EVLWI is a good indicator of early acute lung injury in surgical patients with sepsis.