The initial stage of shock is insufficient effective circulating blood volume caused by blood loss.

Distinct microcirculatory staging and typical clinical manifestations

Susceptible to acute renal failure and enterogenic endotoxemia

Initiation link - all three

Can easily cause systemic inflammatory response syndrome

According to hemodynamics, it is divided into: hyperdynamic shock and hypodynamic shock.

The initial stage of shock

Rapid and significant drop in arterial blood pressure

The initial stage of shock

Clinical manifestations: blood pressure drops significantly in the early stages of shock

Divided according to hemodynamics

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

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

Change mechanism:

Compensatory significance of microcirculatory changes:

Clinical manifestations: pale face, wet limbs (sympathetic nerve excitement, increased sweat gland secretion), cold sweat, thin pulse (cardiac perfusion), blood pressure unchanged or slightly dropped or even increased, pulse pressure decreased (sign of stage I shock) Sexual signs - increased systolic blood pressure, increased diastolic blood pressure), decreased urine output, alertness, irritability

Treatment eliminates the cause, replenishes blood volume, and improves microcirculation disorders

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: Easy to perfuse but difficult to flow, perfusion is greater than flow, and the tissue is in a congested and hypoxic state.

Change mechanism:

as a result of

Clinical manifestations: progressive decrease in blood pressure

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

Characteristics of changes: no perfusion or flow, blood hypercoagulation, no blood supply to tissue cells

mechanism

Serious consequences:

Clinical manifestations:

Treat the primary disease - stop bleeding, replenish blood volume, control infection, repair wounds

Improve microcirculation and increase tissue perfusion

Improve cell metabolism and prevent cell damage

Use humoral factor antagonists and inhibitors

Prevent organ failure

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 rate is second only to the lung 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

(arterial end) resistance vessels: involved in regulating systemic blood pressure and blood distribution

(Venous end) Capacity vessels: involved in adjusting the amount of blood returned to the heart

(Capillary bed) exchange vessels: exchange of substances inside and outside blood vessels

Nervous and humoral regulation - vasoconstriction

Local metabolite regulation - vasodilation

The inflow end of the microcirculation (the arteriolar end has more α-receptors) is more responsive to vasoconstrictor regulation than the outflow end.

Tolerance of microcirculatory inflow side to ischemia and hypoxia<outflow side

The skin, abdominal viscera and renal microcirculatory vessels respond strongly to vasoconstrictor regulation

blood and fluid loss

Extensive burns

hypovolemia

Trauma: pain, blood loss, tissue necrosis

Infection (most common)

allergy

Vascular origin

Heart and macrovascular disease

intense nerve stimulation

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

Classified according to the movement phase (blood volume decreases, vascular bed volume increases, and cardiac output decreases sharply)