血液循环障碍英文课件：休克

1、Disturbance of Circulation Series -Shock,Jianzhong Sheng, MD PhD,Outline,Definition Epidemiology Physiology Classes of Shock Clinical Presentation Management Controversies,Definition,A physiologic state characterized by Inadequate tissue perfusion Clinically manifested by Hemodynamic disturbances Or

2、gan dysfunction,Epidemiology,Mortality Septic shock 35-40% (1 month mortality) Cardiogenic shock 60-90% Hypovolemic shock variable/mechanism,Pathophysiology,Imbalance in oxygen supply and demand Conversion from aerobic to anaerobic metabolism Appropriate and inappropriate metabolic and physiologic r

3、esponses,Pathophysiology,Cellular physiology Cell membrane ion pump dysfunction Leakage of intracellular contents into the extracellular space Intracellular pH dysregulation Resultant systemic physiology Cell death and end organ dysfunction MSOF and death,Physiology,Characterized by three stages Pre

4、shock (warm shock, compensated shock) Shock End organ dysfunction,Physiology,Compensated shock Low preload shock tachycardia, vasoconstriction, mildly decreased BP Low afterload (distributive) shock peripheral vasodilation, hyperdynamic state,Pathophysiology,Shock Initial signs of end organ dysfunct

5、ion Tachycardia Tachypnea Metabolic acidosis Oliguria Cool and clammy skin,Physiology,End Organ Dysfunction Progressive irreversible dysfunction Oliguria or anuria Progressive acidosis and decreased CO Agitation, obtundation, and coma Patient death,Classification,Schemes are designed to simplify com

6、plex physiology Major classes of shock Hypovolemic Cardiogenic Distributive,Hypovolemic Shock,Results from decreased preload Etiologic classes Hemorrhage - e.g. trauma, GI bleed, ruptured aneurysm Fluid loss - e.g. diarrhea, vomiting, burns, third spacing, iatrogenic,Hypovolemic Shock,Hemorrhagic Sh

7、ock,Crit Care. 2004; 8(5): 373381.,Cardiogenic Shock,Results from pump failure Decreased systolic function Resultant decreased cardiac output Etiologic categories Myopathic Arrhythmic Mechanical Extracardiac (obstructive),Distributive Shock,Results from a severe decrease in SVR Vasodilation reduces

8、afterload May be associated with increased CO Etiologic categories Sepsis Neurogenic / spinal Other (next page),SVR: Systemic vascular resistance,Distributive Shock,Other causes Systemic inflammation pancreatitis, burns Toxic shock syndrome Anaphylaxis and anaphylactoid reactions Toxin reactions dru

9、gs, transfusions Addisonian crisis Myxedema coma,Distributive Shock,Septic Shock,SIRS: systemic inflammatory response syndrome,Clinical Presentation,Clinical presentation varies with type and cause, but there are features in common Hypotension (SBP40) Cool, clammy skin (exceptions early distributive

10、, terminal shock) Oliguria Change in mental status Metabolic acidosis,Evaluation,Done in parallel with treatment! H&P helpful to distinguish type of shock Full laboratory evaluation (including H&H, cardiac enzymes, ABG) Basic studies CxR, EKG, UA Basic monitoring VS, UOP, CVP, A-line Imaging if appr

11、opriate FAST, CT Echo vs. PA catheterization CO, PAS/PAD/PAW, SVR, SvO2,Treatment,Manage the emergency Determine the underlying cause Definitive management or support,Manage the Emergency,Your patient is in extremis tachycardic, hypotensive, obtunded How long do you have to manage this? Suggests tha

12、t many things must be done at once Draw in ancillary staff for support! What must be done?,Manage the Emergency,One person runs the code! Control airway and breathing Maximize oxygen delivery Place lines, tubes, and monitors Get and run IVF on a pressure bag Get and run blood (if appropriate) Get an

13、d hang pressors Call your senior/fellow/attending,Determine the Cause,Often obvious based on history Trauma most often hypovolemic (hemorrhagic) Postoperative most often hypovolemic (hemorrhagic or third spacing) Debilitated hospitalized pts most often septic Must evaluate all pts for risk factors f

14、or MI and consider cardiogenic Consider distributive (spinal) shock in trauma,Determine the Cause,What if youre wrong? 85 y/o M 4 hours postop S/P sigmoid resection for perforated diverticulitis is hypotensive on a monitored bed at 70/40 Likely causes Best actions for the first 5 minutes?,Definitive

15、 Management,Hypovolemic Fluid resuscitate (blood or crystalloid) and control ongoing loss Cardiogenic - Restore blood pressure (chemical and mechanical) and prevent ongoing cardiac death Distributive Fluid resuscitate, pressors for maintenance, immediate abx/surgical control for infection, steroids for adrenocortical insufficiency,Controversies,IVF Resuscitation Limited resuscitation in penetrating tra