STUDY - Technical - New Dacian's Medicine
blood
pressure decrease (hypotension) (Classical / Allopathic
Medicine)
Low blood pressure
(hypotension) refers to inadequate intravascular pressure to
maintain the oxygen requirements of the body's tissues.
Although commonly linked to shock, this sign may also result
from cardiovascular, respiratory, neurologic, and metabolic
disorders. Low blood pressure may be drug-induced or may
accompany diagnostic tests - usually, those using contrast
media. It may stem from stress or a change of position -
specifically, rising abruptly from a supine or sitting
position to a standing position (orthostatic hypotension).
Normal blood
pressure varies considerably; what qualifies as low blood
pressure for one person may be perfectly normal for another.
Consequently, every blood pressure reading must be compared
with the patient's baseline. Typically, a reading below 90/60
mm Hg or a drop of 30 mm Hg from the baseline is considered
low blood pressure.
Low blood pressure
can reflect an expanded intravascular space (as with severe
infections, allergic reactions, or adrenal insufficiency),
reduced intravascular volume (as with dehydration and
hemorrhage), or decreased cardiac output (as with impaired
cardiac muscle contractility). Because the body's
pressure-regulating mechanisms are complex and interrelated, a
combination of these factors usually contributes to low blood
pressure.
ALERT:
If the patient's systolic pressure is less than 80 mm Hg or is 30 mm Hg below his baseline:
- quickly evaluate him for a decreased level of consciousness
- check the apical pulse for tachycardia and check respirations for tachypnea
- inspect for cool, clammy skin
- elevate his legs above the level of his heart or place him in Trendelenburg's position and institute emergency measures.
If the patient's blood pressure isn't dangerously low, perform a focused assessment.
If the patient's systolic pressure is less than 80 mm Hg or is 30 mm Hg below his baseline:
- quickly evaluate him for a decreased level of consciousness
- check the apical pulse for tachycardia and check respirations for tachypnea
- inspect for cool, clammy skin
- elevate his legs above the level of his heart or place him in Trendelenburg's position and institute emergency measures.
If the patient's blood pressure isn't dangerously low, perform a focused assessment.
HISTORY:
Ask the patient if he feels unusually weak or fatigued.
Ask the patient if he has blurred vision, unsteady gait, chest or abdominal pain, or difficulty breathing.
Ask the patient if he's had episodes of dizziness. Has he fainted? Do these episodes occur when he stands up suddenly?
Obtain a drug history, including prescription and over-the-counter drugs, herbal remedies, and recreational drugs. Also, ask the patient about alcohol intake.
Ask the patient if he feels unusually weak or fatigued.
Ask the patient if he has blurred vision, unsteady gait, chest or abdominal pain, or difficulty breathing.
Ask the patient if he's had episodes of dizziness. Has he fainted? Do these episodes occur when he stands up suddenly?
Obtain a drug history, including prescription and over-the-counter drugs, herbal remedies, and recreational drugs. Also, ask the patient about alcohol intake.
PHYSICAL
ASSESSMENT:
Take the patient's vital signs, making sure to take blood pressure readings with the patient lying down, sitting, and then standing. Compare readings.
Inspect the skin for pallor, diaphoresis, and clamminess.
Palpate the peripheral pulses. Note paradoxical pulse - an accentuated fall in systolic pressure during inspiration, which suggests pericardial tamponade.
Auscultate for abnormal heart sounds, rate, or rhythm.
Auscultate the lungs for abnormal breath sounds, rate, or rhythm.
Look for signs of hemorrhage, including visible bleeding and palpable masses, bruising, and tenderness.
Check for abdominal rigidity and rebound tenderness; auscultate for abnormal bowel sounds.
Carefully assess the patient for possible sources of infection such as open wounds.
Take the patient's vital signs, making sure to take blood pressure readings with the patient lying down, sitting, and then standing. Compare readings.
Inspect the skin for pallor, diaphoresis, and clamminess.
Palpate the peripheral pulses. Note paradoxical pulse - an accentuated fall in systolic pressure during inspiration, which suggests pericardial tamponade.
Auscultate for abnormal heart sounds, rate, or rhythm.
Auscultate the lungs for abnormal breath sounds, rate, or rhythm.
Look for signs of hemorrhage, including visible bleeding and palpable masses, bruising, and tenderness.
Check for abdominal rigidity and rebound tenderness; auscultate for abnormal bowel sounds.
Carefully assess the patient for possible sources of infection such as open wounds.
SPECIAL
CONSIDERATIONS:
Check the patient's vital signs to determine if low blood pressure is constant or intermittent. The patient may need drug therapy (for example, with dopamine) to increase his blood pressure.
Check the patient's vital signs to determine if low blood pressure is constant or intermittent. The patient may need drug therapy (for example, with dopamine) to increase his blood pressure.
PEDIATRIC
POINTERS:
Normal blood pressure for children is lower than that for adults. Because accidents are common with children, suspect trauma or shock first as a possible cause of low blood pressure.
Remember that low blood pressure typically doesn't accompany head injury in adults because intracranial hemorrhage is insufficient to cause hypovolemia. However, it does accompany head injury in infants and young children; their expandable cranial vaults allow significant blood loss into the cranial space, resulting in hypovolemia.
Another common cause of low blood pressure in children is dehydration, which results from failure to thrive or from persistent diarrhea and vomiting for as little as 24 hours.
Normal blood pressure for children is lower than that for adults. Because accidents are common with children, suspect trauma or shock first as a possible cause of low blood pressure.
Remember that low blood pressure typically doesn't accompany head injury in adults because intracranial hemorrhage is insufficient to cause hypovolemia. However, it does accompany head injury in infants and young children; their expandable cranial vaults allow significant blood loss into the cranial space, resulting in hypovolemia.
Another common cause of low blood pressure in children is dehydration, which results from failure to thrive or from persistent diarrhea and vomiting for as little as 24 hours.
AGING ISSUES:
In elderly patients, low blood pressure commonly results from using multiple drugs that have low blood pressure as an adverse effect.
Orthostatic hypotension due to autonomic dysfunction is another common cause of low blood pressure in elderly patients.
In elderly patients, low blood pressure commonly results from using multiple drugs that have low blood pressure as an adverse effect.
Orthostatic hypotension due to autonomic dysfunction is another common cause of low blood pressure in elderly patients.
PATIENT COUNSELING
If the patient has orthostatic hypotension, instruct him to stand up slowly. If the patient has vasovagal syncope, advise him to avoid situations that trigger episodes. Evaluate the patient's need for a cane or walker.
If the patient has orthostatic hypotension, instruct him to stand up slowly. If the patient has vasovagal syncope, advise him to avoid situations that trigger episodes. Evaluate the patient's need for a cane or walker.
Bibliography:
1. Rapid Assessment, A
Flowchart Guide to Evaluating Signs & Symptoms, Lippincott
Williams & Wilkins, 2004.
2. Professional Guide to
Signs and symptoms, Edition V, Lippincott
Williams & Wilkins, 2007.
3. Guide to common
symptoms, Edition V, McGraw - Hill, 2002.
Dorin,
Merticaru (2010)