NSG 4330 Lecture Notes - Lecture 9: Mean Arterial Pressure, Cardiogenic Shock, Neurogenic Shock
Document Summary
Shock: a syndrome of s/s that describe a sequence of changes that occur when tissue o2 supply does not meet o2 demand. Hypoperfusion: without adequate perfusion, cell begins to switch from aerobic metabolism to anaerobic metabolism producing lactic acid (toxic to cells), which leads to cellular destruction. Mitochondria do not tolerate lactic acid, once destroyed cell can"t metabolize o2 and will die. Heart fills during diastole (relaxation), and expels blood during systole. Perfusion: body cells require a constant supply of o2 and nutrients. Delivery of o2 and nutrients and the elimination of co2 requires 4 things: a properly beating heart (pump, adequate transport medium (fluid): blood or hemoglobin, an intact functioning vessel system (container): one continuous loop, a functioning respiratory system. Mean arterial pressure: average arterial pressure in cardiac cycle, >60 indicates perfusion to organs. Normal map =70: [systolic + (2x diastolic)] / 3. Systemic vascular resistance: reflects changes in the arteries- constrict or dilate.