Overview
Hypertensive emergency refers to a serious life-threatening clinical syndrome in patients with primary or secondary hypertension, in which the blood pressure rises suddenly and significantly (generally more than 180/120 mmHg) under the effect of certain causative factors, accompanied by progressive acute damage to the function of important target organs such as the heart, brain and kidneys. Hypertensive emergencies include hypertensive encephalopathy, intracranial hemorrhage (cerebral hemorrhage and subarachnoid hemorrhage), cerebral infarction, acute heart failure, pulmonary edema, acute coronary syndrome, aortic coarctation, and eclampsia. In the past, the so-called malignant hypertension and hypertensive crisis belonged to this category.
Causes
1. Sympathetic hypertonia
Under the action of various stress factors (such as severe mental trauma, intense emotional changes, excessive fatigue, cold stimulation, climate change, etc.), the sympathetic nerve tone and the vasoconstrictor active substances in the blood increase a lot, which induces the blood pressure to rise sharply in a short period of time.
2. Acute damage to kidney
Renal hypertension is the most common secondary hypertension: including acute and chronic glomerulonephritis, chronic pyelonephritis (when it affects renal function in the late stage), renal artery stenosis, renal stone, renal tumor and so on.
3. Acute vascular disease
Aortic stenosis, multiple aortitis, etc. Increased intracranial pressure due to craniocerebral lesions can also cause secondary hypertension.
4. Endocrine diseases
Such as pheochromocytoma secretion of catecholamines increased dramatically, or thyroid disease caused by thyroxine abnormal release.
5. Abnormal cardiovascular receptor function
Commonly associated with abrupt discontinuation of antihypertensive drugs.
Symptoms
Sudden onset of the disease, the condition is vicious. Usually manifested as severe headache, accompanied by nausea and vomiting, visual disturbances and mental and neurological abnormalities.
1. Significant increase in blood pressure
The systolic blood pressure is elevated above 180 mmHg and/or the diastolic blood pressure is elevated above 120 mmHg.
2. Signs of phytoneurologic dysfunction
Pallor, restlessness, excessive sweating, palpitations, increased heart rate (>100 beats/min), tremor of hands and feet, frequent urination.
3. Signs of acute damage to target organs
(1) Fundus changes Blurred vision, loss of vision, retinal hemorrhage, exudation, optic papillary edema can be seen in fundus examination.
(2) Congestive heart failure Chest tightness, angina, palpitation, shortness of breath, cough, and even foamy sputum.
(3) Progressive renal insufficiency oliguria, anuria, proteinuria, increased plasma creatinine and urea nitrogen.
(4) Cerebrovascular accident: transient sensory impairment, hemiparesis, aphasia, severe agitation or drowsiness.
(5) Hypertensive encephalopathy Severe headache, nausea and vomiting, and neuropsychiatric symptoms in some patients.
Examination
After receiving a patient with severe hypertension, the history and physical examination should be simple and focused, with the aim of identifying hypertensive emergencies and sub-emergencies as soon as possible. A history of hypertension, medication use, and any history of other cardiovascular or renal disease should be asked. In addition to measuring blood pressure, the cardiovascular system, fundus, and nervous system should be carefully examined to understand the extent of target organ damage and to assess for secondary hypertension. If secondary hypertension is suspected, blood and urine specimens should be obtained before treatment is initiated. Laboratory tests should include, at a minimum, an electrocardiogram and urine routine, as shown in Table 1.
Diagnosis
1. When a hypertensive emergency is suspected, a thorough history taking, physical examination, and laboratory tests should be performed to evaluate the functional involvement of target organs in order to clarify as soon as possible whether it is a hypertensive emergency.
2. The blood pressure criterion for the diagnosis of hypertensive emergency is a sharp rise in blood pressure over a short period of time (hours to days), generally systolic blood pressure > 180 mmH and/or diastolic blood pressure > 120 mmHg.
3. Blood pressure measurement should be done with a mercury column sphygmomanometer or a validated electronic sphygmomanometer that meets the measurement standards, and with an appropriately sized airbag cuff, which should wrap around at least 80% of the upper arm; obese people or people with large arm circumference should use a large-size airbag cuff, and children should use a small-size airbag cuff. Before measuring blood pressure, the patient should rest quietly in a sitting position for at least 5 minutes, prohibit smoking or drinking coffee for 30 minutes, and empty the bladder. The upper arm should be placed at the heart level during measurement.
4. In the rapid increase in blood pressure based on any of the following diseases can be diagnosed as hypertensive emergency: ① hypertensive encephalopathy; ② acute coronary syndrome: unstable angina pectoris, myocardial infarction; ③ acute left cardiac insufficiency; ④ acute aortic coarctation; ⑤ acute renal failure; ⑥ acute intracranial vascular accidents: hemorrhagic cerebrovascular accidents, thrombotic cerebrovascular accidents, subarachnoid hemorrhage; ⑦ high Catecholamine state: pheochromocytoma crisis, interaction between monoamine oxidase inhibitors and tyramine, sudden stop of antihypertensive drugs.
5. It should be noted that the level of blood pressure is not proportional to the degree of acute target organ damage. A portion of hypertensive emergencies are not associated with particularly high blood pressure values, and those complicated by acute acute pulmonary edema, aortic coarctation aneurysm, or myocardial infarction should be considered hypertensive emergencies even if the blood pressure is only moderately elevated.
Questions you may be concerned about
What are the diagnostic criteria for hypertensive urgency?
The diagnostic criteria for hypertensive emergencies are a sharp rise in blood pressure within a short period of time and accompanied by other diseases, such as cardiovascular and cerebrovascular lesions, e.g., hypertensive encephalopathy and acute coronary syndrome.
Measurements are taken using a standard-size sphygmomanometer, with the patient resting quietly for 5 minutes, no coffee or smoking for 30 minutes, emptying the bladder, and the upper arm at the same level as the heart. Blood pressure rises sharply over a period of hours to days, usually with a systolic blood pressure >180 mmHg and/or a diastolic blood pressure >120 mmHg.
Sharply elevated blood pressure is accompanied by other diseases such as hypertensive encephalopathy, acute coronary syndrome, i.e., when accompanied by angina pectoris, acute left heart insufficiency, i.e., dyspnea, etc., aortic coarctation, i.e., severe chest pain, etc., acute renal failure, i.e., creatinine elevation, etc., intracranial vascular accident such as acute cerebral vascular accident, and hypercatecholamine state such as pheochromocytoma.
If the blood pressure rises sharply or other discomforts occur in hypertensive patients, it is recommended to consult a regular hospital as soon as possible for professional treatment.
Differential Diagnosis
Hypertensive emergencies should be distinguished from hypertensive subemergencies.
A hypertensive subacute is defined as a significant increase in blood pressure without target organ damage. Patients may have symptoms caused by significantly elevated blood pressure, such as headache, chest tightness, nosebleeds, and irritability. A significant number of patients have problems with poor medication compliance or inadequate treatment.
The degree of elevation of blood pressure is not a criterion for distinguishing hypertensive emergencies from hypertensive subemergencies; the only criterion for distinguishing between the two is the presence of recent onset of acute progressive severe target organ damage.
Treatment
Hypertensive emergencies require immediate antihypertensive therapy to prevent further target organ damage. Short-acting intravenous antihypertensive drugs should be used, depending on the clinical situation, under close monitoring of blood pressure, urine output, and vital signs. During the process of antihypertensive treatment, the functional status of target organs should be closely observed, such as the change of neurological symptoms and signs, and whether the chest pain is aggravated. Due to the pre-existing target organ damage, too fast or excessive lowering of blood pressure may easily lead to lower tissue perfusion pressure and induce ischemic events. Therefore, the initial antihypertensive goal is not to normalize blood pressure, but to gradually reduce blood pressure to a safe level to maximize the prevention or reduction of target organ damage to the heart, brain, kidney and other target organs.
In general, the goal of blood pressure control in the initial phase (within minutes to 1h) is to reduce mean arterial pressure by no more than 25% of the pretreatment level. In the following 2 to 6h the blood pressure is reduced to a safer level, usually around 160/100mmHg, and if such a blood pressure level can be tolerated and the clinical situation is stable, the blood pressure is gradually lowered to a normal level in the following 24 to 48h. When lowering blood pressure, it is necessary to fully consider the patient’s age, duration of disease, degree of elevated blood pressure, target organ damage and combined clinical conditions, and to develop specific programs tailored to the individual. If the patient has an acute coronary syndrome or hypertensive encephalopathy without a previous history of hypertension (e.g., acute glomerulonephritis, due to eclampsia, etc.), the initial target blood pressure level may be appropriately lowered. In the case of aortic coarctation aneurysm, the goal of blood pressure lowering should be as low as a systolic blood pressure of 100 to 110 mmHg, as tolerated by the patient, and generally requires a combination of antihypertensive drugs and an emphasis on the use of adequate amounts of beta-blockers. The goal of blood pressure lowering should also take into account the requirements of target organ-specific therapy, such as thrombolysis.
Blood pressure control in hypertensive emergencies in different clinical situations is detailed in the relevant information.
Once the initial target blood pressure is achieved, oral medications can be started and intravenous medications tapered to discontinuation. After passing the danger period, non-pharmacologic and pharmacologic treatments for hypertension need to be continued. In patients whose blood pressure falls to a safe level in the short term, it should be gradually reduced to normal levels over 3 to 6 months to improve the patient’s prognosis.
Questions you may be concerned about
How to treat hypertensive urgency
The principle of treatment for hypertensive emergency is to reduce the damage to target organs caused by excessive blood pressure, to give fast-acting and effective intravenous antihypertensive drugs as soon as possible for rapid and smooth reduction of blood pressure, while avoiding insufficient perfusion of vital organs caused by too rapid reduction of blood pressure, and to actively search for the causative factors of hypertensive emergency and carry out causative treatment. After the condition is stabilized, the treatment is changed to oral antihypertensive drugs.
Hypertensive emergency is a sudden and obvious increase in blood pressure, usually more than 180/120mmHg, accompanied by progressive impairment of heart, liver, brain, kidney and other vital organs, such as headache, dizziness, nausea, blurred vision, palpitations, respiratory distress, etc., and even heart failure and renal failure.
It is recommended to give fast-acting and effective intravenous antihypertensive drugs such as sodium nitroprusside and nitroglycerin as soon as possible for rapid and smooth antihypertensive treatment to minimize the damage to target organs.
Regardless of whether hypertension has been diagnosed or not, if headache, dizziness, restlessness, chest pain, palpitations, dyspnea, etc. occur, it is recommended to consult a doctor and follow the doctor’s instructions for standardized diagnosis and treatment.
Prevention
Hypertensive emergency is a highly dangerous cardiovascular emergency. It requires immediate, timely and effective treatment. Any hypertensive patient who has a sudden rise in blood pressure and is accompanied by dysfunction of the heart, brain, kidney and other vital organs should immediately go to the hospital and receive specialized treatment to prevent the occurrence of serious complications. Preventive measures such as systematic antihypertensive treatment and avoidance of overwork and mental stimulation can greatly reduce the occurrence of hypertensive emergencies. After stabilization, the patient should gradually switch to conventional anti-hypertensive treatment and adhere to it for a long period of time.