Hemodynamic Monitoring

First Things First (assess & treat for the following)

• Remember, the ultimate goal is to provide adequate oxygen delivery (DO2) to meet the metabolic demands of the tissues.
• Inadequate DO2 leads to anaerobic metabolism and generation of lactic acidosis.
• Primary determinants of DO2 are oxygen content (CaO2) and cardiac output (CO)
• CaO2 = Huffner’s constant (approx 1.39 mL oxygen/gm Hgb) * Hgb * SaO2
• CO = stroke volume (SV) * heart rate (HR)
• Primary determinants of myocardial performance and SV are preload, afterload and contractility.
• Preload is related to muscle fiber length, with increasing force of contractility related to increasing muscle fiber length with an optimal limit (Starling’s Law).
• Left ventricular end diastolic volume (LVEDV) is the preload that causes circumferential LV muscle stretch and contributes to SV.
• Assess the need for invasive monitoring: are non-invasive and/or clinical indicators inadequate for assessment and optimization of DO2?
• Early goal-directed therapy mandates the monitoring of CVP (central venous pressure) and SvO2 (mixed venous saturation) in severe sepsis.