What Is a Hypertensive Emergency?
A hypertensive emergency occurs when blood pressure levels rise to life-threatening values. The American Heart Association stipulates that it’s characterized by readings equal to or greater than 180/120 mmHg. It’s also known as malignant hypertension and is related to partial or total damage to one or more organs of the body.
Emergencies are part of hypertensive crises. The evidence indicates that, on average, 1% of hypertensive people develop it.
Despite its low incidence, today some argue that it’s the second most common cause of death among hypertensive patients, after strokes. Let’s take a look at its symptoms, diagnosis, and how to act in order to treat it.
Symptoms of a hypertensive emergency
As malignant hypertension is always accompanied by organ damage, symptoms vary according to which of them has been affected. The brain, kidneys, and heart are the main candidates, although eye damage is also very common. Among the common symptoms, we highlight the following:
- Headache
- Blurry vision
- Nausea and vomiting
- Lightheadedness and disorientation
- Nosebleed
- Chest pain
- Difficulty breathing/choking sensation
- Decrease in urine production
- Irregular heartbeat (arrhythmias)
- Fainting and seizures
These signs don’t always develop, and some of them can be mistaken for a previously diagnosed condition. Anxiety, numbness in the extremities or the surface of the skin, and altered mental states may also develop.
Lack of reaction is often reported among patients, in part due to mental disturbance. The presence of one or more shouldn’t be ignored, especially if you have a history of high blood pressure.
Causes of a hypertensive emergency
Many causes that can lead to a hypertensive emergency have been identified. Many times, its development doesn’t depend on a single cause but is the confluence of several of them. Among the main causes, we can point out the following:
Lack of adherence to antihypertensives
Most episodes of this type occur in people diagnosed with high blood pressure. On average, 65% of patients who go to emergency rooms for malignant hypertension reported a lack of adherence to treatment, according to some studies.
This indicates that non-compliance with intake is the main cause of this condition. It also indicates that most of the pictures appear in patients with diagnosed hypertension.
It’s important to remember that hypertension is a disease for which there’s no cure. The medications indicated for its treatment are aimed at counteracting the symptoms.
In turn, they prevent the development of side effects of high blood pressure, such as damage to the brain, heart, and kidneys. If adherence to them isn’t maintained, the prognosis is reduced and complications such as hypertensive emergencies arise.
Renal insufficiency
The role of the kidneys in controlling blood pressure is often ignored. These organs produce hormones designed to control blood flow levels. When there’s some type of disorder in them, imbalances in the tension of the blood vessels are very common.
For example, we know that renal parenchyma disease and renal artery stenosis can catalyze malignant hypertension. It has also been shown that among those with primary atypical hemolytic uremic syndrome (in which acute renal failure usually persists), its development is relatively common.
Pregnancy
Blood pressure imbalances during pregnancy are common in most pregnant women, as the evidence indicates. Other research suggests that the development of hypertensive emergencies may be due to a multisystemic process, in which preeclampsia plays a leading role.
Preeclampsia is a condition that occurs after the 20th week of pregnancy and is characterized by increased blood pressure. It’s more common in women over 35 years of age and during the first pregnancy. It can lead to liver or kidney disorders, and even death.
Vascular disorders
Vascular disorders are those that directly affect the arteries or veins. Aortic dissections have been associated with malignant hypertension. Also, there’s evidence that thoracic aortic thrombosis may be the cause.
Some diseases that generate vascular imbalances such as systemic sclerosis have also been identified as possible triggers.
Other conditions that can cause chronic high stages of hypertension are tumors of the adrenal gland and myocardial infarction. Although it’s unlikely that by themselves they generate a hypertensive crisis, the following risk factors may join the others in its development:
- Indiscriminate use of recreational drugs
- Excessive consumption of alcohol and tobacco
- Being overweight or obese
- Exceeding the recommended dose of certain drugs (or maintaining an intake without medical supervision)
- Disorderly eating, with a prevalence of fat, processed foods, and salt
Sometimes, the real cause of the condition can’t be determined. In any case, when the patient goes to the emergency room, doctors proceed with their diagnosis and then treat the sequelae generated by the elevation in blood pressure.
Diagnosis of a hypertensive emergency
As we indicated at the beginning, a hypertensive emergency is diagnosed when blood pressure is equal to or greater than 180/120 mmHg and there’s evidence of damage to the target organs. The latter is important because if there’s an absence of it, it is a hypertensive urgency, another type of crisis related to increased tension in the arteries.
The protocol to be followed in emergency rooms, therefore, will consist of the following:
- Determine whether it’s a hypertensive emergency or another type of condition.
- Evaluate its etiology. This will be done, among other things, by analyzing the patient’s medical history.
- Determine the collateral damage generated by malignant hypertension.
Specific steps in the diagnostic process
- Anamnesis: Anamnesis is the medical term for the analysis of data from the clinical history of patients. The doctor will scrutinize it for possible signs of the development of the crisis. It will also assess whether the person belongs to a modifiable risk group (weight, diet, habits) and their routine before the pressure rise occurred.
- Physical examination: With the help of a blood pressure monitor, the blood pressure levels at the moment will be determined. The test will be done several times, with intervals of 1 to 5 minutes, to achieve a target value.
- Imaging tests: Used to discover damage to the body. CT scans and the electrocardiogram are the most frequently chosen tests.
- Urine and blood tests: To complement the previous tests, the specialist will also order both tests. In principle, they’ll look for evidence of liver or kidney damage, as well as other values that may be a sign of collateral damage.
Most diagnosed patients are admitted to the intensive care unit (ICU) to proceed with treatment and improve prognoses.
Treatment for hypertensive emergency
The first thing to do in a hypertensive emergency is to lower blood pressure values to a safe range for the body. The second is to counteract the possible damage caused to the organ.
Treatment for the latter case is very varied, as it depends on which area has been affected and to what degree. This will be best determined when the lab and imaging tests are complete.
Some practical cases
Following the evidence in this regard, below we’ll point out a treatment model based on the damage caused by:
- Malignant hypertension with aortic dissection: The best option is intravenous esmolol, with a dose ranging from 500-1000 mcg/kg. If resistance to it is maintained, it can be supplemented with nitroglycerin or nitroprusside intravenously.
- Hypertensive emergency with acute lung edema: Intravenous nitroglycerin, nitroprusside, or clevidipine are used. Administration of beta-blockers is contraindicated.
- Patients with acute myocardial infarction and malignant hypertension: In this case, intravenous esmolol is preferred as the first option. If necessary, intravenous nitroglycerin can also be used.
- Hypertensive emergency with renal failure: The use of nicardipine, fenoldopam, and clevidipine is indicated.
The choice varies according to the condition and is always personalized. The dose and the speed with which it descends to normal pressure also change according to the case. It’s of great importance that very rapid descents are avoided, as these are related to secondary complications.
For example, we know that they can cause cerebral, myocardial, and renal hypoperfusion. In general, experts recommend that the reduction be carried out in a period of 30-60 minutes, approximately 15% of the value presented. In severe cases, the time can be shortened to 5-10 minutes.
It’s not uncommon for several days or weeks to pass before values return to normal. The patient must remain under strict medical supervision and adhere to treatment to partially or fully recover the function of the affected organs.
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