Septic shock in the elderly
Introduction
Introduction to septic shock in the elderly Septic shock is a critical syndrome in which acute microcirculatory perfusion is caused by microorganisms and their toxins, directly or indirectly, leading to tissue hypoxia, cellular damage, metabolism and dysfunction, and even multiple organ failure (MOF). basic knowledge The proportion of illness: more common in elderly people with chronic lung disease, the incidence rate is 5-10% Susceptible people: the elderly Mode of infection: non-infectious Complications: disseminated intravascular coagulation
Cause
The cause of septic shock in the elderly
Bacterial infection (30%):
The most common pathogens in senile septic shock are Gram-negative bacteria, of which Enterobacteriaceae are the most common. Others are Pseudomonas aeruginosa, Acinetobacter, meningococcus, Bacteroides, etc., Gram-positive bacteria, such as Staphylococcus, B-type hemolytic streptococcus, pneumococci and enterococci, in addition, influenza bloodthirsty The cases caused by bacilli are gradually increasing. Some viral diseases, such as hemorrhagic fever with senile renal syndrome, are also prone to shock during the course of the disease. Gram-negative bacilli sepsis, fulminant epidemic cerebrospinal meningitis Pneumonia, bacterial dysentery, suppurative cholangitis and abdominal infections.
Microcirculatory disorders (20%):
The neuroendocrine response of the elderly to infection, such as adrenal secretion of catecholamines, cortex secretion of cortisone is the same as that of young people, and the increase in secretion time is prolonged, causing strong vasospasm ( receptor excitation), microcirculation blood perfusion, tissue Ischemia, hypoxia is more obvious, and acidosis is more obvious.
Cellular metabolic disorders (10%):
Cellular metabolic disorders can be secondary to reduced blood perfusion, but can also be primary, ie, before hemodynamic changes occur, the responsiveness of the organs and cells of the elderly is low, the biochemical reactions within the cells, and the number of enzymes And the activity is reduced, and aging septic shock is more prone to cell metabolism disorders.
Metabolic changes, electrolyte and acid-base balance disorders (20%):
The prolonged period of neuroendocrine response in the elderly after infection increases the time during which sugar and fat metabolism are disturbed, and the reserve capacity of metabolic regulation decreases, making the body's metabolic disorders more common, acidosis and electrolyte disorders are common.
The impact of basic diseases (10%):
The elderly are often accompanied by hypertension, arteriosclerosis, lung disease, and low renal function. Once the shock is caused, the condition is more likely to worsen and multiple organ dysfunction occurs.
Prevention
Elderly septic shock prevention
Mucosa, skin soft tissue and upper respiratory tract infection should be avoided, especially local wounds and postoperative attention should be paid to the treatment of wounds; it is advisable to detect the infected lesions early and use appropriate antibiotics.
Complication
Complications of septic shock in the elderly Complications, disseminated intravascular coagulation
In the advanced stage, DIC and important organ failure and disseminated intravascular coagulation may occur.
Symptom
Symptoms of septic shock in the elderly Common symptoms Shock hypotension, slow pulse, coma, cyanosis, consciousness disorder, no urine, dry skin, hypothermia, hypoxemia
1. The primary disease is more common in pulmonary infection: the primary disease of senile septic shock is more common in the lungs, biliary tract and intestinal tract infections.
2. Insidious onset: The primary disease of senile septic shock is not serious, the onset is slow, low fever, rarely high fever, normal body temperature or not rising up to half, more chills (this is different from young and middle-aged), sometimes Tachycardia is the only manifestation.
3. Gastrointestinal symptoms are more common: gastrointestinal tract symptoms, nausea, vomiting, bloating, diarrhea, anorexia, etc. are common in elderly patients with septic shock.
4. The disturbance of consciousness is more common: the brain tissue is aging due to aging, the nerve cells gradually shrink or decrease, and in the shock state, the blood supply to the brain cells suddenly decreases, accompanied by the accumulation of metabolites or toxins, plus water and electrolyte balance. Disorders can aggravate the damage of brain cells. The elderly with septic shock develops rapidly. More than half of the patients have different levels of disturbance of consciousness. They are characterized by apathy, syncope, delirium or coma. They are often misdiagnosed as cerebrovascular disease, sometimes The only symptom of aging septic shock in the elderly.
5. Shock performance is not typical: in elderly patients with septic shock, the skin is dry more than wet, the pulse is not clear, oliguria is not significant, it is difficult to estimate the time of shock, the elderly have high blood pressure or high blood pressure, it is difficult to use blood pressure values Judging shock, systolic blood pressure <13.3kPa (100mmHg), diastolic blood pressure <8kPa (60mmHg), should be judged as hypotension.
6. Easy to develop into multiple organ failure (MOF): the decline of systemic organ reserve function caused by aging, rapid development of senile septic shock, DIC and important organ failure, manifested as low refractory Blood pressure, extensive bleeding (skin mucous membrane, internal organs), oliguria or no urine, rapid breathing, cyanosis, accelerated heart rate, low heart bluntness or galloping, arrhythmia, heart rate is not fast or relatively slow pulse, appearance Gray, central venous pressure and/or elevated pulmonary wedge pressure, electrocardiogram can show myocardial damage, subendocardial ischemia, arrhythmia and conduction block, etc., can appear adult respiratory distress syndrome (ARDS), brain Dysfunction can cause coma, convulsions, paralysis of the limbs, and pupils, changes in breathing, etc.
7. Acid-base and water, electrolyte imbalance is more common: acid-base and water caused by aging, electrolyte balance regulation function decline, old-age septic shock is prone to water, electrolyte and acid-base balance disorders, manifested as hyponatremia Symptoms, hypokalemia or hyperkalemia, respiratory alkalosis, metabolic acidosis and mixed acidosis.
Examine
Elderly septic shock examination
1. Blood: Most white blood cell counts increase, at (15 ~ 30) × 109 / L, neutrophil increased with nuclear left shift phenomenon, hematocrit and hemoglobin increased as a marker of blood concentration, concurrent DIC platelet reduction .
2. Etiology examination: routinely carry out blood (or other body fluids, exudates) and pus culture (including anaerobic culture) before the antibiotic treatment, and isolate the pathogenic bacteria for drug susceptibility test, sputum lysate test (LLT) facilitates the detection of endotoxin.
3. Urine routine and renal function test: When renal failure occurs, the relative density of urine changes from the initial high to low (1010 or so); blood urea nitrogen and creatinine values increase; urine/creatinine ratio < 20; urine osmotic pressure decreased, urine / blood percolation ratio <1.1; urine sodium (mmol / L) excretion > 40; renal failure index > 1, sodium excretion score (%) > 1, the above examination can be with pre-renal Identification of renal insufficiency.
4. Acid-base balance blood biochemical examination: carbon dioxide binding capacity (CO2CP) is a clinically measured parameter, but in respiratory failure and mixed acidosis, blood gas analysis must be performed simultaneously to determine blood pH, arterial blood PaCO2, standard HCO3- And the actual HCO3-, buffer alkali and alkali remaining, etc., urine pH determination is simple and easy, blood lactic acid content determination has prognostic significance.
5. Determination of serum electrolytes: The blood sodium of patients with shock is mostly low, and the level of potassium is different, depending on the state of renal function.
6. Determination of serum enzyme: The measurement of serum ALT, CPK, LDH isoenzyme can reflect the damage of liver, heart and other organs.
7. Hemorheology and examination of DIC: blood flow rate is slowed during shock, capillary stasis, blood cells, fibrin, globulin, etc., blood viscosity increases, so the initial blood is hypercoagulable, followed by fiber The lysis of the sputum is converted to hypocoagulability. The examination of DIC includes both consumptive coagulopathy and fibrinolysis: the former has platelet count, prothrombin time, fibrinogen, and kaolin thromboplastin time; the latter includes Thrombin time, fibrin degradation products (FDP), plasma protamine paracoagulation (3P) and ethanol gel test, and euglobulin dissolution test.
8. ECG, X-ray examination, etc. can be carried out as needed.
Diagnosis
Diagnosis and diagnosis of septic shock in the elderly
Diagnostic criteria
The diagnosis of senile septic shock mainly depends on clinical characteristics and laboratory tests.
The clinical manifestations of senile septic shock are atypical, the performance of primary infection is not typical, and there are many comorbidities. The basal blood pressure of the elderly is high, and the treatment is not timely, which makes the shock time difficult to estimate, and is easily misdiagnosed and missed.
Patients with senile infectious diseases who are prone to concurrent shock should be closely observed for changes in the condition, pay attention to the initial manifestations of shock, and the following signs of infection should be alert to the possibility of shock: excessive heat (<36 ° C), or excessive heat (> 40.5 ° C), but the former is the most common, the latter is rare; non-central nervous system infections appear to have disturbances of consciousness, such as apathy, coma, etc.; breathing is accelerated with hypoxemia and/or metabolic acidosis, and No abnormal findings in chest X-ray films; low blood pressure or decreased orthostatic blood pressure (>4.0 kPa); significantly increased heart rate (not parallel to elevated body temperature) or arrhythmia, decreased urine output, peripheral white blood cells and thrombocytopenia, Increased serum lactate value, unexplained liver and kidney damage.
In order to make timely diagnosis, closely observe the changes of the disease, and formulate treatment plans, we must master some clinical, hemodynamic and laboratory indicators to judge the state of microcirculation function. Clinical indicators include consciousness and mental state (reflecting the blood flow of the central nervous system) Perfusion), respiratory rate and amplitude (reflecting lung function and presence of acid-base imbalance), skin color, temperature and humidity (reflecting peripheral blood perfusion), jugular and peripheral vein filling, pulse, nail fold microcirculation and fundus examination The amount of urine (reflecting the internal organs, especially the blood perfusion of the kidneys), etc., hemodynamic parameters include blood pressure and pulse pressure, central venous pressure (CVP) measurement.
Peripheral blood leukocytes and neutrophils may be normal, low or increased in elderly patients with septic shock; hematocrit and hemoglobin may increase (blood concentration); blood (or other body fluids, exudates) should be taken before antibiotic use ) and pus culture (including anaerobic culture), after the isolation of pathogenic bacteria for drug sensitivity test, blood lactate content determination is meaningful for prognosis, severe shock increased significantly, other such as liver, renal function test, myocardial enzyme Learning and electrocardiogram examination, blood gas analysis and hematuria electrolysis test and hemorheology examination and DIC examination are all helpful in the diagnosis and treatment of senile septic shock.
Differential diagnosis
Septic shock should be differentiated from hypovolemic shock, cardiogenic shock, anaphylactic shock, neurogenic shock, hypovolemic shock due to massive hemorrhage (internal or external bleeding), loss of water (eg vomiting, diarrhea) , intestinal obstruction, etc.), loss of plasma (such as large-area burns, etc.) caused by a sudden decrease in blood volume, cardiogenic shock caused by low blood pressure, often secondary to acute myocardial infarction, acute pericardial tamponade, Severe arrhythmia, various myocarditis and cardiomyopathy, acute pulmonary heart disease, etc., anaphylactic shock is often caused by the body's allergic reaction to certain drugs (such as penicillin, etc.) or biological products, neurogenic shock can be traumatic, Acute pain, cerebrospinal injury, anesthesia accident, etc., due to nerve action, the peripheral blood vessels are dilated, and the effective blood vessel volume is relatively reduced.
