traumatic shock
Introduction
Introduction to traumatic shock Traumatic shock (traumatic shock) is caused by severe violent blows to the body, important organ damage, major bleeding, etc., which reduces the effective circulating blood volume, insufficient microcirculation perfusion, and the formation of various factors such as severe pain and fear after trauma. The body's decompensated syndrome. Therefore, traumatic shock is more complicated than the pathogenesis of simple hemorrhagic shock. Traumatic shock is common in both normal and wartime, and the incidence is related to the nature of the wound, the injury site, the injury energy, the time of action, the degree of blood loss, the normal physiological condition of the patient and the early treatment after injury. With the development of the expressway As well as the increase in violent crimes, the incidence of severe trauma and multiple injuries is increasing, and the incidence of traumatic shock is also increasing. The incidence of shock in multiple injuries can be as high as 50% or more. basic knowledge The proportion of the disease: the probability of the population is 0.021%, more common in car accidents Susceptible people: no specific people Mode of infection: non-infectious Complications: coma
Cause
Causes of traumatic shock
Trauma (98%)
Trauma shock is often divided into: traffic accident injury; machine damage; fall injury; other injuries, the main factor causing the above trauma is "violence". From a dynamic point of view, the cause of trauma is the adverse effect of kinetic energy on the body.
Pathogenesis
There are many reasons for shock, and the types are different, but the pathophysiological processes of various shocks are basically the same.
Prevention
Traumatic shock prevention
Traumatic shock is basically low volume shock. But cardiovascular changes and effects cannot be ignored. That is to say, after trauma, cardiac function is inhibited and vasoconstriction changes. Auxiliary cardiovascular function drugs can be used.
It is worth noting that fluorocapsules should not be used in patients with pale complexion, cold, freckle, bruising, and other peripheral circulation. In addition, there are nerve and mental factors induced by traumatic stimulation. It is also worth noting that trauma is often accompanied by internal or external bleeding, and infection may occur after the injury. Thus, traumatic shock can also be associated with hemorrhagic shock and septic shock. In clinical diagnosis, disease judgment and treatment and treatment, it should be comprehensively analyzed and carefully considered for proper treatment. The situation is more common in car accidents, falling buildings and war wounds. Because it is mostly multiple injuries or combined injuries, the injury is complicated and the condition is changeable. It is difficult to treat and should be fully paid attention. Traumatic shock can cause systemic and local immune dysfunction, which is prone to infection. Antibiotics and drugs that enhance immune function should be given.
Complication
Traumatic shock complications Complications
Shock can often cause disseminated intravascular coagulation. Once disseminated intravascular coagulation occurs, the microcirculatory disorder will be more serious, and the shock condition will worsen. This is because:
1 extensive microvascular obstruction further aggravates microcirculatory disorders, further reducing the amount of blood returning;
2 blood coagulation substance consumption, activation of secondary fibrinolysis and other factors cause bleeding, thereby reducing blood volume;
3 Soluble fibrin multimers and their cleavage products can block the mononuclear phagocytic system, thus preventing endotoxin from the intestines from being sufficiently eliminated.
Due to the occurrence of disseminated intravascular coagulation and the increasing aggravation of microcirculation, the systemic hypoxia and acidosis will become more and more serious due to the severe deficiency of systemic microcirculation perfusion caused by blood pressure reduction; severe acidosis It can rupture the lysosomal membrane in the cell, release lysosomal enzymes (such as proteolytic enzymes, etc.) and certain shock drivers (such as endotoxin), which can cause serious or irreversible damage to the cells, thus The functional metabolic disorders of important organs, including the heart and brain, are also more serious, which causes great difficulties in treatment. Therefore, this period is also called the refractory period of shock.
Symptom
Traumatic shock symptoms Common symptoms Pulse rate increase expression indifferent coma breath shortness burn wounds fecal odor secretions metabolic acidosis cold sweat anxiety
Traumatic shock is closely related to the injury site, the degree of injury and the amount of bleeding. In the emergency department, the initial judgment must be made according to the injury. When the critically ill injury is newly diagnosed, it is important not to pay attention to the open injury and ignore the extremely valuable traumatic signs. Observing the casualty's complexion, consciousness, breathing, external bleeding, posture of the injured limb, and the degree of tearing of the clothes and contamination by blood stains, etc., can provide a very important basis for deciding which first-aid measures to take.
Look up
(1) Look at the mind: In the early stage of shock, the brain tissue is hypoxic, the wounded are excited, irritated, anxious or excited. As the disease progresses, the brain tissue is aggravated by hypoxia, the injured person's expression is indifferent, the consciousness is blurred, and the late stage is coma.
(2) Look at the cheeks, lips and skin color: When the surrounding small blood vessels contract, the microvascular blood flow is reduced, the color is pale, and the later due to lack of oxygen, congestion, and bruising color.
(3) Look at superficial veins: When the circulating blood volume is insufficient, the superficial veins of the neck and limbs are atrophied.
(4) Look at the filling time of capillaries: normal ones can fill quickly within 1 s, and when microcirculation is insufficient, the filling time is prolonged.
2. Palpation
(1) Touch pulse: In the shock compensation period, the surrounding blood vessels contract, the heart rate increases, and the pulse can be increased before the systolic blood pressure drops. This is an important basis for early diagnosis.
(2) Touching the temperature of the extremities: the surrounding blood vessels contract, the blood flow of the skin is reduced, the temperature of the extremities is lowered, and the limbs are cold.
3. Blood pressure
Clinically, the level of blood pressure is often used as a basis for the diagnosis of shock, but in the shock compensation period, due to increased peripheral vascular resistance, systolic blood pressure can be normal, diastolic blood pressure can be increased, pulse pressure can be <4.0kPa (30mmHg), And the pulse rate is increased, it is easy to be misdiagnosed, so the pulse rate should be combined with blood pressure.
Shock index = pulse rate / systolic blood pressure (mmHg)
Generally, it is about 0.5. If the index is 1, it means that the blood volume is lost by 20% to 30%. If the index is >1 to 2, it means that the blood volume is lost by 30% to 50%.
The Guangzhou General Hospital of Guangzhou Military Region has summarized the blood pressure pulse rate difference method through clinical observation. The normal value is 30 to 50. The value changes from large to small, suggesting a tendency to shock. The calculation method is:
Systolic blood pressure (mmHg) - pulse rate (times / min) = positive number or > 1 is normal; if equal to 0, it is the critical point of shock; if it is negative or <1, it is shock, the smaller the negative number, shock The deeper, from negative to 0 or to positive, indicating that the shock is getting better.
In short, the observation of blood pressure should pay attention to early signs such as increased pulse rate and small pulse pressure. If the shock is aggravated, blood pressure drops, and the symptoms are obvious, it is likely to lose the opportunity for treatment.
4. Urine volume
The normal urine volume is about 50ml/h. In shock, the renal blood perfusion is poor, the urine filtration is decreased, and the urine output is reduced. It is an important indicator for observation of shock. Indwelling catheterization can be used to continuously monitor urine volume, specific gravity, electrolytes, and protein. And pH.
5. Central venous pressure and pulmonary artery pressure
(1) Central venous pressure (CVP): The normal value is 6~12cmH2O. The measurement of CVP can understand the state of blood flow, but CVP does not directly reflect the blood volume or liquid requirement in the diagnosis and treatment of shock, but reflects The ability of the heart to pump back the blood volume and suggest that the venous return flow is insufficient. In addition, CVP has a certain effect on understanding the right heart function, but it does not accurately reflect the left heart function. Therefore, the degree of shock must be determined by blood pressure, pulse, and hourly. Comprehensive measurement of urine volume, such as CVP is lower than the normal value, even if the blood pressure is normal, it indicates that the blood volume is insufficient, and fluid replacement is needed. In the process of infusion, unless CVP is significantly elevated, the infusion should be continued to blood pressure, and the pulse and urine volume reach normal levels. And then slow down to maintain, such as CVP higher than 10 ~ 20cmH2O, low blood pressure, less urine, in addition to some pathological factors, generally indicates that the heart function is significantly poor, such as continued infusion, will increase the burden on the heart, it should be used to improve the heart Beat function.
(2) pulmonary arterial wedge pressure (PAWP): the use of floating catheter from the external jugular vein or cephalic vein, through the subclavian vein, superior vena cava to the pulmonary artery, determination of pulmonary artery and capillary embedding, its normal value For 6 ~ 12mmHg, under normal conditions of breathing and circulation, the average pulmonary capillary pressure is basically consistent with pulmonary venous pressure, so it can correctly reflect the expansion or congestion pressure of the pulmonary circulation. In addition, PAWP is closely related to the mean pressure of the left atrium. Not higher than the latter 1 ~ 2mmHg, the left atrial mean pressure is closely related to the average left ventricular diastolic pressure; normal is higher than the former 2 ~ 6mmHg, so PAWP can more accurately reflect the change of left atrial diastolic pressure than CVP And the whole cycle function, if the PAWP exceeds 20mmHg, it means that the left heart function is severely incomplete; if <6mmHg, indicating that the blood volume is relatively insufficient, it is necessary to increase the left heart filling to ensure the circulation function. If the PAWP is at 12-18mmHg, it indicates the left ventricular muscle relaxation. functioning normally.
6. Estimation of the degree of shock
Clinically, shock can be divided into light, medium and heavy three degrees.
Examine
Traumatic shock examination
Laboratory tests are of little value in guiding early rescue, but they are helpful in judging the degree of shock and can be used as a basis for changes in the condition, such as blood routine examination, hematocrit, platelet measurement, blood pH and blood gas analysis. Go as soon as possible.
No related auxiliary inspection.
Diagnosis
Diagnostic diagnosis of traumatic shock
1. History: Patients with traumatic shock have a history of severe trauma or bleeding.
2. Clinical features "5P" signs, namely pale pallor, perspiration, prostation, pulselessness, and pulmonary deficiency.
3. General examination: mainly monitoring of blood pressure and pulse.
(1) Systolic blood pressure reduction: generally more than 13.3 kPa.
(2) Pulse pressure: generally less than 4 kPa.
4. Special monitoring:
(1) Urine volume: It is the main indicator for observing shock. The normal person is 50ml/h, and the hourly urine volume during shock is generally less than 25ml.
(2) central venous pressure: normal value is 6 ~ 12cmH2O shock is often low.
(3) Blood gas analysis: a metabolic acidosis change.
