外科急诊创伤(英文)-休克及出血

Cardiovascular System
Delivery of nutrients and O2 to tissues and cells
Transportation of waste products produced by metabolism to liver and kidneys
外科急诊创伤(英文)-休克及出血
Sections
Introduction to Hemorrhage & Shock
Hemorrhage Shock
Introduction to Hemorrhage & Shock
Hemorrhage
▪ Abnormal internal or external loss of blood
Realized a fall in BP could account for all symptoms of shock
Represents a generalized failure of the body to deliver sufficient amounts of O2 to its tissues
1800’s
Injury to one part of the body results in often fatal effect
Strychnine to stimulate NS; seizures
Electrical current alcohol
来自百度文库shock was not a process of dying, rather a marshaling of the bodily defenses in a struggle to live”
Treatment Goals
Recognition of early shock Appropriate airway
management Rapid transportation to
appropriate facility
Hemorrhage
Circulatory System Hemorrhage Classification Clotting Factors Affecting Clotting Hemorrhage Control Stages of Hemorrhage Hemorrhage Assessment Hemorrhage Management
Blood Pressure
Directly proportional to the product of the CO multiplied by SVR
BP = CO x SVR SVR, resistance to flow in the
system (systemic vascular resistance)
SHOCK
“a momentary pause in the act of death”
“But a more careful examination soon serves to show that deep mischief is lurking in the system; that the machinery of life has been rudely unhinged, and the whole system profoundly shocked; in a word, that the nervous fluid has been exhausted” ( A System of Surgery, 1859)
Delivery of CO2 to lungs
Components
Heart or pump Blood vessels or pipes Blood or fluid
Circulatory System
Heart
▪ Parasympathetic Nervous System
Slows rate Vagus Nerve
▪ Sympathetic Nervous System
Increases rate Cardiac Plexus
Review Terminology
▪ Stroke Volume ▪ Preload ▪ Ventricular Filling ▪ Frank-Starling
Mechanism ▪ Afterload ▪ Cardiac Output
SVxHR=CO 5L/min
▪ Fick Principle
Cardiac Output
Volume of blood pumped in 1 minute = 4-6L
SV x HR SV = amount of blood ejected
from left ventricle with each contraction
S/S represent compensation measures utilized by the body to maintain delivery of O2 to vital organs
Delay of appropriate therapy, cascade of events results in damage to organs
Stroke Volume
Preload
▪ Represents filling of the ventricle ▪ Volume of blood delivered to atria prior to
ventricular diastole ▪ Dependent on venous return
Homeostasis
▪ Tendency of the body to maintain a steady and normal internal environment
Shock
▪ INADEQUATE TISSUE PERFUSION ▪ Transition between homeostasis and death