Infectious shock is also known as septic shock or toxic shock. It is a state of microcirculatory disturbance caused by pathogenic microorganisms and their toxins in the human body, resulting in tissue hypoxia, metabolic disorders, cellular damage and even multi-organ failure. Elderly people, infants and children, chronic diseases, long-term malnutrition, immune deficiencies and patients with malignant tumors or after major surgery are particularly vulnerable.
The treatment of shock should be comprehensive, should actively treat the primary disease, and at the same time for the pathophysiology of shock to give supplemental blood volume, correct acidosis, adjust vasodilator function, eliminate red blood cell agglutination, prevent microcirculatory stasis and maintain the function of important organs.
I. Treatment of primary diseases
Infection should be actively and rapidly controlled. The principles of antimicrobial use are: strong selection, broad antibacterial spectrum, sensitive to pathogenic microorganisms, large doses, combined use (generally more than two antibiotics used simultaneously), and regular intravenous drip. To reduce the symptoms of toxicity, use adrenocorticosteroids in large quantities for a short period of time under effective antibacterial therapy. Use aminoglycoside antibiotics with caution in those with impaired renal function.
While using powerful antibacterial, septic lesions should be treated promptly. Recently, it has been proposed abroad that Gram-negative bacterial infection shock, after the use of antibiotics, the sensitive bacteria in blood and tissues are killed, releasing a large amount of endotoxin circulating in the blood stream, which aggravates the clinical manifestations of patients, thus raising the importance of choosing the timing of drug delivery.
Second, anti-shock treatment
1.Replenishment of blood volume
Infectious shock due to hypoxia and the impact of toxins, resulting in patients with increased vascular bed volume and capillary permeability, there are different degrees of blood volume deficiency (according to estimates, the total volume of capillaries in shock is 2 to 4 times larger than normal). Replenishing blood volume is one of the most basic and important means of treating and rescuing shock.
(1) Colloid fluid The main functions of low-molecular dextrose (molecular weight 20,000 to 40,000) are.
①Prevent the interpolation of red blood cells and platelets, inhibit thrombosis and improve blood flow;
②Increase plasma colloid osmotic pressure and antagonize plasma extravasation, thus expanding blood volume;
③Dilute blood, reduce blood viscosity, accelerate blood flow, and prevent the occurrence of DIC; its small molecular weight, easy to excrete from the kidneys, and renal tubular non-reabsorption, has a certain osmotic diuretic effect. The daily dosage of low-molecular dextran is 500-1500ml, and it is used with caution in people with bleeding tendency and cardiac and renal insufficiency. If the blood volume is still insufficient after using a certain amount of low molecular dextrose, plasma, albumin or whole blood can be used in appropriate amounts (blood transfusion should be used with caution when there is DIC).
(2) Crystalloids The application of balanced saline and saline can increase the amount of functional extracellular fluid and ensure a certain volume of circulation.
The principles of volume expansion are: crystalloid first and then gel, fast and then slow, acid correction and protection of cardiac function at the same time. The blood volume has been replenished on the basis of.
①Good tissue perfusion, clear consciousness, red lips, warm extremities, cyanosis disappears;
②Systolic blood pressure <11.97kpa (90mmHg), pulse pressure >3.99kpa (30mmHg);
③Pulse rate <100 times/min;
④Urine volume >30ml/h;
⑤ Hemoglobin drops back and hemoconcentration disappears.
2.Correction of acidosis
Acidosis is present in shock, and it is more serious when combined with hyperthermia. Correction of acidosis can enhance myocardial contractility and improve the depression of microcirculation (acidemia has a procoagulant effect). However, it is necessary to improve the perfusion of microcirculation while correcting acidity, otherwise metabolites cannot be transported away and acidosis cannot be improved.
Generally, 4-5% sodium bicarbonate is used, the dosage is 400ml/d for mild shock and 600-900ml/d for severe shock, and the dosage can be adjusted according to the change of blood pH. THAM is easy to penetrate into the cells, which is conducive to the correction of intracellular acidosis, and has the effect of sodium-free and osmotic diuresis, which is suitable for patients who need to limit sodium. The usual dosage of 3.63% THAM0.6ml/kg can improve Co2CP1vol%.
3.Preventing and controlling microcirculatory stagnation
(1)Application of vasoactive drugs
①Dopamine: It is the predecessor of norepinephrine. The effect on the heart is to excite β receptors, increase myocardial contractility, so that the increase in cardiac blood output; the excitatory effect on the blood vessels is mainly direct excitation of the α receptors of the blood vessels, so that vasoconstriction, but the effect is weak. Small dose has mild constricting effect on peripheral blood vessels, but has dilating effect on visceral blood vessels. Large doses (20 μg/kg/min) excite mainly α receptors and cause constriction of small blood vessels throughout the body.
Dobutamine is more effective than norepinephrine in increasing cardiac output and weaker than isoproterenol in raising blood pressure. Occasionally, dopamine causes heart rhythm disturbance. The usual dosage is 10-20mg dissolved in 200ml of 5% glucose solution at a drip rate of 2-5μg/kg per minute. In patients with cardiac and renal insufficiency in shock, the cardiotonic effect of dobutamine is weakened while the accelerating effect of heart rate is enhanced, so it should be used with caution.
②Alamine (m-hydroxylamine): It can replace the norepinephrine stored in the nerve endings and make the release of norepinephrine work, thus indirectly excite α and β receptors. Compared with norepinephrine, the vasoconstrictor effect of alamin is weak, but the effect is slow and long-lasting, and maintains stable blood pressure. The usual dose is 10-20mg dissolved in 200ml of 5% glucose solution and administered quietly.
③Norepinephrine: the effect on α receptors is stronger than that on β receptors, the former causes vasoconstriction, the latter strengthens myocardial contractility. Although norepinephrine increases blood pressure, it has a strong vasoconstrictive effect and reduces blood perfusion to important organs, which is not conducive to the correction of shock, so it is rarely used to increase blood pressure.
Isoprenaline: It is a pure β-receptor stimulant. β-receptor excitation can increase heart rate and increase myocardial contractility, and at the same time can dilate blood vessels and release the constricted state of microcirculation. This drug increases cardiac output through the mechanism of increasing heart rate and decreasing peripheral resistance, which can cause arrhythmia. The usual dose is 0.2mg in 200ml of glucose solution.
Phentolamine and benzylamine: They are α-adrenergic receptor blockers, which dilate the microcirculation and improve blood perfusion. Phentolamine has rapid action, but short maintenance time. Benzylamine has a long duration of action, dilates microvasculature and improves microcirculatory perfusion, and has a certain effect on increasing renal blood volume. Commonly used dose of benzylamine 0.5 ~ 1mg/kg body weight in 200ml of liquid intravenous drip.
(2) Application of anticholinergic drugs
It has good effect of relieving vasospasm, and has the effect of excitation of respiratory center, relieving bronchospasm and improving sinus rhythm. In shock 654-2 dosage can be very large, the patient tolerates a larger amount, the side effects are small, easier to grasp than atropine. Large doses of atropine can cause restlessness, and scopolamine can inhibit the cerebral cortex and cause drowsiness. Commonly used dose of atropine 1~2mg, 654-2 10~20mg, injected intravenously every 15~20 minutes. Scopolamine 0.01~0.03mg/kg every 30 minutes.
(3) Prevent coagulation of platelets and red blood cells
①Low molecular dextrose (usage and dose as before).
Aspirin and pansentine can inhibit the production of prostaglandins and TXA2 in the body. TXA2 has a strong platelet agglutination effect and can cause vasoconstriction and also prolong the prothrombin time. Pansentin can also inhibit platelet agglutination and prevent microthrombosis. The dose is 150-200mg/d, divided into intramuscular or intravenous injection.
③Danshen can release the aggregation of red blood cells and improve microcirculation to prevent blood flow stagnation. The dose is 8-12ml/d added into low molecular dextrose drip.
Maintain the function of important organs
1.The prevention and treatment of cardiac insufficiency
Severe shock and late shock is often complicated by cardiac insufficiency, which occurs mainly because of myocardial ischemia, hypoxia, acidosis, bacterial toxins, electrolyte disorders, the role of myocardial inhibitory factors. When signs of cardiac insufficiency appear, the rate and amount of infusion should be strictly controlled. In addition to cardiac stimulants, vasoactive drugs such as dopamine may be given to prevent blood pressure from falling.
Also give oxygen, correct acidosis and electrolyte disorders as well as infusion of energy combination to correct the imbalance of cellular metabolism. Naloxone is an ideal drug for anti-shock, which can increase the heart beat volume and blood pressure, and has the effect of stabilizing the lysosomal membrane and reducing the myocardial inhibitory factor.
2.Maintenance and prevention of lung function
The lungs are one of the main target organs of shock, and pulmonary failure is often complicated by intractable shock, while cerebral hypoxia and cerebral edema can also lead to respiratory failure. Therefore, all shock patients must immediately use the nasal cannula or mask to administer oxygen, keep the respiratory tract unobstructed, timely removal of respiratory secretions, and if necessary, tracheotomy. If there is a clear shock pneumogenesis, intermittent positive pressure respiration should be performed or given end-expiratory positive pressure respiration can be effective.
3.Maintenance of renal function
Shock patients appear oliguria, anuria, azotemia and other manifestations of renal insufficiency, which occurs mainly due to the reduction of effective circulating blood volume and insufficient renal blood flow. The severity of renal damage is closely related to the severity of shock occurrence, duration and resuscitation measures. Actively take comprehensive measures against shock to maintain sufficient effective circulating volume is the key to protect renal function.
4.Control of cerebral edema
Brain tissue requires about 20% of the total basal oxygen consumption, and is very sensitive to low oxygen, which can easily lead to the occurrence of pulmonary edema. Clinically, there may be altered consciousness, transient convulsions and signs of increased intracranial pressure, and even brain herniation may occur. The treatment should be timely head cooling, use of mannitol, tachypnea and high dose of dexamethasone (20-40mg) to prevent the development of cerebral edema.
5.Treatment of DIC
DIC is a serious complication of infectious shock and an important cause of death in refractory shock. once the diagnosis of DIC is established, active anti-shock, improvement of microcirculation and rapid and effective control of infection and early heparin treatment should be given on the basis of removing the lesion. The dose of heparin is 0.5~1mg/kg (usually 1.0mg for the first time), and it should be given by IV every 4~6 hours to prolong the clotting time to 2-3 times normal.
The duration of drug administration will be decided according to the degree of shock reversal and DIC control or not. If the clotting time is too prolonged or the bleeding is aggravated, equal amount of fisetin can be used to counteract it. At the same time, pansentin, salvia injection and peptidase can be used as adjuvant therapy.
Application of adrenal cortical hormone
There is no consensus on the application of hormones in infected shock. However, animal experiments suggest that early application of hormones can prevent the occurrence of infectious shock. The main role of adrenocorticotropic hormone is to.
1.Binding endotoxin and reducing the damage of toxin to the organism.
2, stabilize the role of lysosomes. Lysosomes are normally in the cell plasma, and in shock, the pH in hypoxic cells decreases and the lysosomal membrane ruptures, releasing a large amount of proteolytic enzymes and causing cell destruction. Hormones can stabilize the lysosomal membrane and prevent the release of enzymes.
3.High dose hormone has release vasospasm and can improve microcirculation.
4.Increase the heart beat output.
5.Restore the function of phagocytosis of reticuloendothelial system.
6.Stabilize the complement system and inhibit the activation of neutrophils.
7.Protect the normal oxidative phosphorylation process of liver mitochondria and the function of liver enzyme system. About the dose and time of hormone use differs at home and abroad. Foreign countries over to the high dose short course method. Domestic use of medium dose (such as hydrocortisone 5-10mg/kg per day), general use of 1 to 2 days, the shock situation improved after the rapid withdrawal.
V. Other
According to the mechanism of action of bioactive substances and cytokines, anti-lipid A monoclonal antibody (murine Eλ) (λHAIA) and anti-TNF monoclonal antibody have been tried and received certain effect in the treatment of infectious shock, but further in-depth study is needed.