Hypotension in the elderly

Introduction to low blood pressure in the elderly There are relatively few domestic studies on senile hypotension. In fact, it has important clinical significance as high blood pressure: long-term symptomatic hypotension can seriously affect the quality of life of the elderly, leading to progressive decline of various important organ functions; The low blood pressure can cause the elderly to faint, fall, trauma, acute myocardial infarction, stroke and even life-threatening, so it must be highly valued. basic knowledge The proportion of the disease: the incidence rate of the elderly over 50 years old is about 0.01%-0.02%, more common in the thin body Susceptible people: the elderly Mode of infection: non-infectious Complications: angina pectoris myocardial infarction fracture

The cause of hypotension in the elderly

Drug factors (20%):

Old people taking antihypertensive drugs such as methyldopa, stable drugs such as chlorpromazine, diuretics, hydrochlorothiazide, furosemide, etc., anti-angina drugs such as heartache, nitroglycerin, etc., can also cause hypotension .

Position factor (20%):

The elderly have poor neuromodulation function, arteriosclerosis makes their arterial elasticity decline, patients with weak constitution, long-term bed rest, and standing in a stuffy environment for too long, are easy to induce orthostatic hypotension.

Urinary factors (10%):

Physical factors (10%):

Disease factor (5%):

Genetic factors (10%):

Genetic factors can also cause hypotension in the elderly.

Pathogenesis

The cause of hypotension in the elderly is complicated, and the pathogenesis has not yet been elucidated. It is speculated that it is related to age-related diseases and neuroendocrine dysfunction or long-term effects of drugs.

Elderly hypotension prevention

Elderly people with hypotension should pay attention to the following points:

1. Asymptomatic hypotension Because there is no significant reduction in cerebral blood flow, more treatment is not needed, but patients should be encouraged to get up and walk, avoid prolonged bed rest or sedentary, should correct medical diseases, increase blood volume, improve blood circulation and enhance heart function. The measures, dehydration should not be used diuretics, should develop good bowel habits to avoid excessive force during defecation.

2, slowly change position and posture, avoid sudden awakening or quickly change position, and should rest for 2 ~ 3min each time you change position, so that the body position compensation response adapts to each position change, get up in the morning to stand or start walking Before, I should sit on the bed for a few minutes. When I go to the bathroom and toilet, I fall down due to orthostatic hypotension, which can cause confusion and loss of consciousness. Fractures and other injuries can occur. Bedside urinals or urinals can be used to prevent accidents.

3, to avoid excessive meals, eat less meals, eat a lot of easily digestible carbohydrates, appropriate intake of sodium salt, moderate drinking water, to maintain normal blood volume.

4, bath water temperature should not be too high, bath time should not be too long.

5, reduce the risk of going out during the heat, reduce a lot of sweating.

6, wearing elastic stockings, increase the amount of blood back.

7, try to avoid drugs that are not indispensable to affect blood pressure.

Elderly low blood pressure complications Complications angina pectoris myocardial infarction fracture

Easy to induce angina or myocardial infarction, stroke, fracture and so on.

Symptoms of hypotension in the elderly Common symptoms Blood pressure drop weight loss fatigue heart rate dizziness dizziness nausea hearing loss dizziness response dull muscle atrophy

1, clinical manifestations

(1) Asymptomatic hypotension is almost always found in health checkups or other outpatient clinics. It is occasionally found in hospitals. The elderly are well tolerated by hypotension, coupled with slow response, other diseases, and other factors, low blood pressure. Neglected, in fact, after detailed medical history, there are very few asymptomatic patients, patients often have mild fatigue, even or dizziness, dizziness, etc., generally no organic lesions, low blood pressure and small pulse pressure, heart rate bias Slow, introverted, not easy to be excited, obesity and weight loss can be seen, with more physically weaker people, older people than young people, women more common than men.

(2) Symptomatic hypotension mostly has mild or moderate brain and other organ ischemia symptoms, such as weakness, dizziness, headache, insomnia, poor memory, difficulty in concentration, etc., some patients with high blood pressure, Combined with a large area, after severe myocardial infarction, blood pressure is low for a long time. In addition to hypotension, there is evidence of myocardial ischemia.

(3) Sudden onset of symptomatic hypotension, sudden loss of consciousness with the disappearance of body position tension, that is, the occurrence of syncope.

The prodromal symptoms of syncope are:

1 After excessive physical or mental work, dizziness, dizziness, and change of body position often make it worse.

2 After dizziness, blurred vision, vertigo, black sputum and so on.

3 may have mild hearing loss or tinnitus.

4 weak and weak, standing unstable, have a desire to dump.

5 pale, nervous, talking hard, and even unable to speak.

6 can be accompanied by nausea, vomiting and other gastrointestinal symptoms.

7 Most patients do not have time to support the support or immediately take the position, and the seat will immediately faint and fall.

A considerable number of patients have no presence when they are fainting. Some patients may have facial or head skin abrasions. Older people may have fractures due to falling. They may also have cerebrovascular accidents or acute myocardial infarction due to sudden and significant decrease in blood pressure. Old people can be pneumonia due to prolonged cold after fainting. Except for cardiogenic and neurogenic (central) sexually, there is no significant change in breathing. Heart rate can be slow or fast, heart sounds are low and weak; deep and shallow nerve reflexes exist. (unlike coma), the patient can clearly describe the situation before the syncope or the environment in which it occurs. It usually occurs for ten to ten minutes, rarely more than 20 minutes. After the patient is awake, there is still pale and sweaty. Hand and foot are cold, unable to talk, a small number of fainting time is not long and there is no serious trauma or comorbidity, can be automatically or under the support of others to the nearby medical units, there are no obvious abnormal findings; only the original cause of syncope For patients with organic diseases, the corresponding positive signs can still be checked.

2, classification

(1) Asymptomatic hypotension: that is, although the blood pressure is low, but because of the small amount of activity in the elderly, the work is more stable and the lower blood pressure is better, so it can be asymptomatic in a quiet state; Because the elderly automatically adjust blood pressure function, brain blood flow can not be timely, adequate supply and symptoms.

(2) Symptomatic hypotension: When the systolic blood pressure is as low as 13.4 to 9.3 kPa (100 to 70 mmHg), most people's cerebral blood flow perfusion can be ensured by self-regulation mechanism; however, when the systolic blood pressure is less than 9.3 kPa (70 mmHg) Because of the inability to ensure the minimum blood flow perfusion required for normal brain activity, cerebral ischemia symptoms can be corrected, and those who are severe can be irreversible and have a poor prognosis.

(3) orthostatic hypotension: a significant decrease in blood pressure from the supine position to the upright position, called orthostatic hypotension, the specific criteria are as follows: the subject is quietly supine for 10 minutes and then measured blood pressure per minute, pulse rate 1 time When the blood pressure value is approximated twice, the average value is taken as the blood pressure value before the body position change. After that, let it stand up automatically, place the right upper arm at the same level as the heart, measure the blood pressure, pulse, record immediately and After the data per minute, compared with the pre-station, a total of 7min was recorded. After the standing, the blood pressure decreased by at least 2.7/1.3kPa (20/10mmHg) or the systolic pressure fell below 10.7kPa (80mmHg), and maintained for more than 2min. In recent years, Domestic people have applied electric supine-upright tilting bed with automatic, timed ECG, blood pressure, pulse rate monitor to diagnose orthostatic hypotension or orthostatic syncope, which is more convenient, safe and accurate.

Postural hypotension can be further divided into:

1 reversible orthostatic hypotension: more common, the elderly, especially long-term bedridden, many lower limbs or systemic venous return, such as phlebitis, venous structural defects, muscle atrophy, muscle pump weakening, etc., if at the same time Myocardial infarction, heart failure or inadvertent use of strong diuretics can promote orthostatic hypotension, methyl dopa, guanethidine and other reversible arteriolar reflexes that affect sympathetic function. When patients change their position, they are also easy. The orthostatic hypotension occurs, the blood pressure drops significantly during systole, the diastolic blood pressure is basically unchanged, and the heart rate increases. The syncope can occur at some time, and the cause can be corrected after removal.

2 irreversible orthostatic hypotension: in some patients with autonomic dysfunction, especially -adrenergic nerves are weakened, release of vasoconstrictor mediators, orthostatic hypotension can occur, in addition, shy-Dragers syndrome is a slow start Disease, progressive aggravation of senile diseases, manifested as orthostatic hypotension, autonomic dysfunction (such as urination, sweating and sexual dysfunction, etc.) and other nervous system dysfunction, autonomic nerve center, cerebellum, cerebral palsy The olive nucleus, pons, spinal cord and other places are obviously degenerated, atrophy, poor prognosis and high mortality. The mortality rate of a group of patients who were followed up for 5 years in China was 44.1%.

Elderly low blood pressure check

Blood tests: blood erythrocytes and hemoglobin-reducing severe anemia can cause blood pressure to decrease; when malignant anemia in megaloblastic anemia with neurological dysfunction, orthostatic hypotension can occur; hematocrit determination helps to determine blood volume such as dehydration Changes; the increase of white blood cells in the blood is beneficial to the diagnosis of septic shock; blood glucose can be significantly reduced can cause hypotension and even shock, at this time should also pay attention to distinguish this hypoglycemia insulin secretion is too much or Edison disease, caused by hypopituitarism; Determination of the Kanghua reaction of blood and cerebrospinal fluid is helpful in diagnosing spinal cord spasm that can cause hypotension; electrolyte disorders such as hypokalemia caused by various causes can also be the cause of hypotension.

1. Conventional electrocardiogram and dynamic electrocardiogram:

Helps to eliminate tachyarrhythmia or severe sick sinus syndrome, III degree atrioventricular block, cardiac arrest or myocardial infarction caused by hypotension; patient active telephone remote electrocardiogram has a relatively slow development of symptoms of syncope or symptoms Syncope can instantly record ECG activity at the time of onset; some short-term (<5min) recorders with recall function are useful for determining the relationship between syncope aura or syncope and arrhythmia; cardiac electrophysiological examination (EPS includes transesophageal EPS) Should be used in the above-mentioned examination failed to determine the cause of the highly suspicious elderly, need to stop anti-arrhythmia drugs about 2 half-life before the investigation, the indications: unexplained syncope; frequent attacks (more than 5 times a year), no organic The basis of sexual heart disease; difficult to identify ventricular or supraventricular tachyarrhythmia with syncope or important for the selection of drugs, the possible positive result of syncope on EPS is: sinus node recovery time (SNRT) > 1500ms; corrected sinus Knot recovery time (SNRTc) 525ms; HV> 80ms (or AV, VA time is significantly prolonged); found on the basis of compression of carotid sinus: AVBII degree or III degree, continuous 5s or cardiac still 4.0s

2, ventricular late potential (LP) examination of the following indicators may be meaningful for the detection of arrhythmia causing syncope:

(1) QRS filtering time > 110ms.

(2) QRS filtering terminal 40ms, voltage <20V, time 32ms.

(3) QRS filtering is 40ms at the end, and the voltage square root is <25V. It is generally considered that patients with suspected spontaneous ventricular tachycardia can be screened for EPS.

3. Echocardiography, emission computed tomography and cardiac X-ray examination:

Can understand the condition of the heart that causes hypotension, such as mitral valve heart often suggest mitral stenosis; aortic valve calcification often suggests calcific aortic stenosis, can cause sudden syncope during exercise; left atrial myxoma or globular thrombosis Blocking the mitral valve can cause orthostatic hypotension, echocardiography can confirm the diagnosis, and can calculate the ejection fraction and other indicators, which can help to judge the heart function.

4, brain CT and MRI examination:

It is helpful to determine the relationship between intracranial lesions and cerebrovascular disease and syncope; EEG helps to define the relationship between focal epilepsy and hypotension.

5, carotid sinus allergy test:

It helps to determine the cause of syncope when the head is turning, but it must be done with caution under ECG monitoring, and only one side can be tested at a time.

6, autonomic nervous system function check:

Such as examination of cardiovascular reflex, sweating reflex and pupil reflex excessive breath test, inspiratory fist test, stress test, cold pressure test, fatigue test, atropine heart reaction test, isoamyl nitrite inhalation test, temperature increase test The adrenaline eye drop test, the methacholine eye drop test, etc. may be helpful for differential diagnosis, but some of them may be dangerous to the elderly, and some may be replaced by the detected neurological signs. There are not many domestically adopted these examiners.

7. Upright tilt test (HUT):

Since Kenny reported the use of HUT to diagnose vasovagal syncope in 1986, foreign countries have done a lot of observations on this type of syncope in all ages. Although there are fewer HUTs in elderly patients in China, they are done by young and middle-aged patients. HUT has accumulated some experience and can be used as a reference for the development of elderly HUT.

(1) Subject: Unexplained syncope for more than 1 time. After various related examinations and comprehensive analysis, the clear cause of heart, brain, endocrine and drug reaction was excluded.

(2) Method:

1Basic test: 3 days before the test, all drugs affecting cardiovascular function and autonomic nerves were stopped, fasted for breakfast or only a small amount of liquid food, and the experiment was carried out in the morning. First, the venous channel was established, and the defibrillator, atropine, and different were prepared. Drugs such as propyl adrenaline and adrenaline were used. The patient was placed on an electric tilting bed for 10 minutes. The electrocardiograph and the auto-timed blood pressure were connected. The pulse monitor recorded blood pressure, pulse and electrocardiogram (12-lead) every 2 minutes. Then the tilting bed is turned to 80°, which is close to the erect. The patient is attached to the bed with the bed, standing for 60 minutes (the maximum length of 25 minutes), and the above parameters are still regularly recorded, such as the occurrence of hypotension and (or The symptoms of bradycardia related to bradycardia or similar episodes of syncope are positive. Immediately return the patient to the supine position and stop the test. If the erect tilt is still negative for 60 minutes, let the patient return to the supine position for 5 to 10 minutes. Stimulation test.

2 stimulation test: that is, tilt plus graded intravenous drip isoproterenol test.

A. Level 1: 2g/min, intravenous infusion for 5min, then tilted 80° in the same way for 10min, the positive reaction was terminated, if it was still negative, no adverse drug reaction was found, and the supine position was restored. After 10 minutes, the second level was performed.

B. Level 2: 5 g/min, the method is the same as above, if the two-stage test does not induce syncope, it is negative.

(3) Criteria for judging positive results: There are syncope or syncope in the tilt test (same or similar to previous sweating, nausea, vomiting, blurred vision and drowsiness) before the onset of syncope, accompanied by the following two One of the performances:

1 systolic pressure <10.7 kPa (80 mmHg).

2 sinus bradycardia (ventricular rate <50 times / min) or sudden drop in heart rate 20%, transient II degree above the atrioventricular block, sinus arrest or borderline escape rhythm.

(4) Results: The positive rate of the basic test group was 17.2%33.3%; the basic test plus stimulation test can increase the positive rate to 75.8%87.5%, and the specificity is high, the accuracy is high, and the stimulant is administered with isoproterenol. When the positive rate is higher than 2g/min at 5g/min, the positive case appears 2~58min after the start of the tilt, especially in the middle and late stage. Therefore, in order to reduce the false negative, the tilting duration can not be shortened artificially. Taking metoprolol or atropine or 654-2, respectively, can make the positive conversion rate of the two test groups positive by 77.8%, 100% and 80%, indicating that the -blocker and vagus nerve inhibitors are basic and stimulating tests. There are inhibitory effects, which can prevent syncope, but -blockers may be less effective than vagus nerve inhibitors. In addition, a small number of patients in the stimulation test have numbness, palpitations, symptoms disappear after 10 minutes of withdrawal, and no other serious adverse reactions have been found. .

(5) Possible mechanism of HUT: HUT induces vasovagal syncope and drug stimulation or inhibits the possible mechanism of syncope. When erected, the venous return blood volume is reduced, left ventricular filling is insufficient, arterial blood pressure is decreased, reflex causing arteriolar contraction, heart rate Accelerated, myocardial contractility increased, sensitive individuals with excessive myocardial contraction, reduced ventricular end-diastolic volume, resulting in stimulation of the "C" fiber in the posterior wall of the left ventricle, the latter is the unmyelinated cholinergic nerve endings, left ventricular pressure Increased can make it excited, which leads to sudden inhibition of sympathetic nerves. The vagus nerve temporarily loses the antagonism of sympathetic nerves, peripheral vasodilation, bradycardia, sharp drop in blood supply to the brain, leading to syncope, and the tilting system is close to an upright position. Therefore, the occurrence of syncope can be induced; isoproterenol can enhance the contractility of the myocardium and increase the sensitivity of the afferent nerve fibers, thus increasing the sensitivity of the HUT, increasing the positive rate of the test, and -blocking. Agent and vagus nerve suppression can weaken myocardial contractility, prevent "C" fiber agonism and vagus nerve hyperexcitability, so Inhibit the occurrence of syncope.

In summary, HUT is an effective method for diagnosing unexplained syncope and evaluating treatment effects, and is convenient, non-invasive, safe, accurate, and worth promoting. Of course, the elderly are induced with syncope and using -blockers, vagus nerve inhibitors, and When isopropyl adrenaline is used, it is necessary to have more strict indications and contraindications, and to observe and monitor more closely.

Diagnosis and diagnosis of hypotension in the elderly

Diagnostic criteria

1. The diagnosis of asymptomatic hypotension mainly depends on the blood pressure value falling below the diagnostic criteria or diagnostic criteria.

2, the diagnosis of symptomatic hypotension, in addition to the blood pressure value to reach the standard, also need to have the corresponding clinical performance and laboratory positive test results.

3. Diagnosis of orthostatic hypotension:

(1) The blood pressure is lowered due to the change from the lying position or the sitting position, and the blood pressure ratio is reduced by at least 2.7/1.3 kPa (20/10 mmHg) or the systolic pressure is below 10.7 kPa (80 mmHg), and can be maintained for more than 2 minutes. After returning to the lying position, it quickly rises to normal or near normal.

(2) Clinical manifestations associated with the above-mentioned symptomatic hypotension, disappeared or reduced after lying down.

(3) It is possible to find out the cause (as mentioned above).

(4) It is possible to find certain functional incentives, such as prolonged bed rest or excessive exercise, high temperature, fever and other environmental regulation abnormalities, dehydration, anemia, hemorrhage, dialysis treatment, hyponatremia, hypokalemia and other effective circulating blood. Insufficient amount or electrolyte disorder, septic shock, etc.; pay special attention to finding the adverse effects of drugs, because the hypotension caused by drugs accounts for about half of the orthostatic hypotension in the elderly. These drugs include diuretics, vasodilators, and antihypertensive drugs. , sleeping pills, tranquilizers, anti-shock drugs, certain antipsychotics, hypoglycemic agents, etc.

(5) The above auxiliary examination can further determine the cause.

Differential diagnosis

It is of practical significance to identify three types of orthostatic hypotension, such as autonomic dysfunction or multiple system atrophy or sympathetic sensitivity, because their prognosis and treatment are different. The common features of the first two are standing systolic blood pressure and diastolic blood pressure. Both decreased and heart rate did not increase, all have neurological symptoms such as bladder sphincter, impotence and no sweat; different points are multiple system atrophy and muscle atrophy, Parkinson's disease, iris atrophy, eye surgery muscle paralysis and dyspnea Equal cone and extrapyramidal signs, and, in patients with autonomic dysfunction, norepinephrine in the blood is reduced in the supine position, does not increase in the standing position, is very sensitive to the infusion of norepinephrine blood pressure; and multi-system atrophy Norepinephrine can be increased in a small amount when the position is established, and the prognosis is better in patients with dysfunction. After long-term, appropriate activities and drug treatment, the symptoms can be improved to a certain extent. Patients with multiple system atrophy have difficulty in treatment, high mortality, and sympathetic sensitivity. Type orthostatic hypotension is different from the previous two types of spontaneous orthostatic hypotension. In the standing position, only systolic blood pressure drops without significant diastolic blood pressure drop. Low, heart rate accelerated more than 25 times / min, generally no autonomic nervous system symptoms, normal norepinephrine levels in the blood, normal reaction in standing position, suitable for treatment with -blockers.

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