9/18/17 Applying Your Data to Affect Your Care: Case Studies in Hemodynamics B. McLean, MN, RN, NP-BC, CCNS-BC, CCRN, FCCM 404-626-2843 Barbaramclean.com
[email protected] Introduction Critical care is a concept, not a location, which frequently begins with ED intervention and culminates in ICU admission and continued management – Peter Safar Why the microcirculation is important in shock and why we MUST evaluate it! • where oxygen exchange takes place • plays a central role in the immune function • Plays a central role in insulin resistance • Plays a central role in maintaining vascular tone • During shock : first to go and last to recover 1 9/18/17 Cardiac Function • Function – Continuous propulsion of blood through arteries to capillaries to veins • Right heart circulation • Right heart fills from systemic veins (partially deoxygenated) • Right heart ejects to pulmonary artery (partially deoxygenated) • Left heart circulation • Left heart fills from pulmonary veins (maximally oxygenated) • Left heart ejects to aorta (maximally oxygenated) • Capillaries – microscopic vessels that allow for exchange of gases, nutrients and metabolic waste • Pulmonary capillaries perfuse alveoli, delivering CO2 and taking up Oxygen • Systemic capillaries perfuse tissues, delivering oxygen and taking up CO2 Capillaries • Capillaries – Smallest blood vessels connect arterial outflow and venous return – Microcirculation – flow from metarteriole through capillaries and into postcapillary venule – Exchange vessels – primary function is exchange between blood and interstitial fluid – Lack tunica media and tunica externa • Substances pass through just one layer of endothelial cells and basement membrane – Capillary beds – arise from single metarteriole • Vasomotion – intermittent contraction and relaxation • Throughfare channel – bypasses capillary bed Consider this….