Hypertension Blog

Alcohol and Cocaine

Both alcohol and cocaine cause hypertension. Excessive ingestion of alcohol can cause a patient to exacerbate his preexisting hypertension, or it can induce hypertension. And cocaine produces devastating effects on blood pressure by increasing the release of norepinephrine, a powerful vasopressor produced by the body in response to hypotension and stress. This can result in acute hypertension, tachycardia, tremor, and seizures as well as coronary artery vasoconstriction from a CVA or Ml.

Poisons

Many poisons can elevate blood pressure and cause hypertension. Some common poisons include cyanide, phencyclidine, and black widow spider venom. Treatment varies depending on the poison, and it usually relieves the poison-induced hypertension.

Pregnancy

Pregnancy-induced hypertension can threaten the lives of both the mother and infant. It causes elevated blood pressure, proteinuria, and edema and may lead to abnormalities in the mother’s coagulation system and liver function. The only treatment for pregnancy-induced hypertension is delivery of the infant.

Stress

For some patients, even mild stress can cause a rise in blood pressure. In response to a stressful event, the patient perceives a stressor, and his body initiates a fight-or-flight reaction. Physical signs and symptoms of stress-induced hypertension include decreased gastrointestinal motility, pupil dilation, and increased perspiration, all of which result from sympathetic nervous system stimulation that causes increased blood pressure and increased heart and respiratory rates.

With the white-coat phenomenon, a patient has elevated blood pressure readings in his physician’s office or the hospital but normal readings elsewhere. To determine if a patient has true hypertension, a physician may order repeated measurements over time or ambulatory measurements.

In postoperative patients, stress-related hypertension commonly results from sympathetic stimulation caused by pain, bladder distention, hypothermia, or respiratory compromise.

Sleep Apnea

Sleep apnea can contribute to the development of hypertension. During apnea, the tongue and soft palate relax and fall back, obstructing the airway either partially or completely. As a result, the patient can’t breathe. His oxygen levels fall, and carbon dioxide levels rise, resulting in acidosis and vasoconstriction of the pulmonary arterioles. Eventually, the patient partially awakens, gasps, and reopens his airway. Episodes of apnea may last from 15 to 90 seconds and occur repeatedly during the night.

Diseases Causing Vasculitis

Scleroderma, polyarteritis nodosa, lupus erythematosus, rheumatoid arthritis, and nonspecific arthritis may cause vasculitis in some patients. About one-half of these patients subsequently develop hypertension because of the effect the diseases have on the arterioles and major arteries.

Treatment of a patient who has had a cerebrovascular event may involve drug therapy and surgery.

If your hypertensive patient has experienced an ischemic or hemorrhagic eVA, the physician may prescribe an antihypertensive drug to lower his blood pressure. However, if elevated Iep results from a hemorrhagic eVA, his blood pressure shouldn’t be reduced too quickly or too much.

The physician may prescribe heparin I.V. to treat TlAs and ischemic eVAs, but not to treat hemorrhagic eVAs because it increases the risk of bleeding. If heparin is administered for a TIA or an ischemic eVA, titrate the drug to maintain the PTT at about twice the normal level. Once your patient’s PTT has reached this therapeutic level, the physician may prescribe warfarin, which is taken orally. Typically, heparin therapy continues until the warfarin brings the prothrombin time to a therapeutic level.

If the patient has experienced an ischemic eVA, the physician may prescribe recombinant t-PA to disintegrate the thrombus or embolus that’s causing the occlusion .

A physician also may prescribe a drug that prevents platelet aggregation, such as aspirin, dipyridamole, or ticlopidine hydrochloride, to prevent thrombus and embolus formation and to treat an ischemic CVA.

After the patient has been stabilized, the physician may use drug therapy to minimize disability. Typically, he’ll prescribe mannitol I.V. to reduce cerebral edema. This drug draws fluid out of the extravascular space and into the vascular system.

If the patient has a large hematoma displacing a considerable amount of surrounding tissue or if drug therapy fails to lower his elevated ICP, he may require a craniotomy to remove the hematoma and relieve pressure.

A surgeon may perform an endarterectomy to reduce the risk of future TIAs or a CVA. This procedure removes atherosclerotic plaque that’s obstructing blood flow to the brain. Commonly, endarterectomies are performed on the common carotid bifurcation and the arch of the aorta.

If the surgeon can’t remove the obstruction causing an ischemic CVA, he may perform an extracranial-intracranial bypass. This procedure involves bypassing the intracranial artery just beyond the obstruction with an extracranial artery, thus restoring blood flow.