blood and fluid loss

burn

trauma

Infect

allergy

cardiac dysfunction

intense nerve stimulation

Classification by cause: hemorrhagic shock, burn shock, traumatic shock, septic shock, anaphylactic shock, cardiogenic shock, neurogenic shock

Classification by moving parts

It is the early stage of shock, also called ischemic hypoxic zone. During this period, microcirculatory blood perfusion is reduced and tissue ischemia is severe, so it is also called ischemic hypoxic period.

Characteristics: less perfusion and less flow, less perfusion than flow, and the tissue is in a state of ischemia and hypoxia.

Mechanism of change: Strong excitement of the sympathoadrenal medullary system and an increase in vasoconstrictor substances

The compensatory significance of microcirculatory changes: 1. It helps to maintain arterial blood pressure and can increase the amount of blood returned to the heart. It is the first line of defense to increase the amount of blood returned to the heart. It plays the role of self-infusion; increases cardiac output; increases peripheral resistance. ; 2. Helps blood supply to the heart and brain

Clinical manifestations: generally pale face, clammy limbs, cold sweats, accelerated pulse, decreased pulse pressure, decreased urine output, and irritability.

It is also called the microcirculatory congestion phase, decompensation phase, and shock phase; during this phase, blood flow slows down significantly, red blood cells and platelets aggregate, and hypoxia becomes more severe.

Characteristics: irrigation but little flow, irrigation greater than flow, tissue showing congestion and hypoxia state

Change mechanism: 1. Microvascular dilation mechanism and blood stasis mechanism

Decompensation and the creation of a vicious cycle

Clinical manifestations: blood pressure drops significantly, pulse is thin, and veins collapse 2. Patient is apathetic or even comatose 3. Renal blood flow is severely insufficient, with oliguria or even anuria 4. Microcirculatory congestion, cyanosis or mottling of skin and mucous membranes

Microcirculatory failure stage or refractory stage, also known as irreversible stage DIC stage

Characteristics of changes: capillaries undergo paralytic dilation, blood vessels lose their responsiveness to catecholamines, and microthrombi form without perfusion.

Mechanism of change: release of tissue factor into blood, endotoxin

Serious consequences: extensive bleeding

Linchuan manifestations: 1. Circulatory failure 2. Complicated DIC 3. Vital organ disorders

During shock, microcirculation is severely disrupted, tissue perfusion is low, and cells are hypoxic.

Energy deficiency and water, electrolyte, acid-base disorders

acute renal failure

The incidence is second only to the lungs and liver, with clinical manifestations such as oliguria or anuria, azotemia, hyperkalemia, acid metabolism, etc.

Mechanism: Sharp decrease in blood volume, continuous ischemia and hypoxia, release of toxins leading to the production of inflammatory mediators