Normal blood pressure is usually defined as a systolic pressure below 120 mm Hg and a diastolic pressure below 80 mm Hg. This is often expressed as 120/80.
Various factors influence your blood pressure. For instance, as a nurse, you might be asked about the relationship between lifestyle and blood pressure. Here's what you need to understand.
| Age |
Healthy systolic blood pressure range |
| Adult (18–60 years) |
90–120 mm Hg |
| Older adult (over 60) |
Up to 129 mm Hg |
For instance, if a 65-year-old patient has a regular systolic blood pressure reading of 130 mm Hg, this may be considered as borderline high and the patient may be at greater risk of developing heart diseases.
Interestingly, research shows that systolic blood pressure tends to rise with age due to increased stiffness of large arteries and long-term build-up of plaque within the artery walls.
Symptoms and Regulation of Blood Pressure
In nursing, recognising the symptoms of abnormal blood pressure and understanding how blood pressure is regulated are crucial skills. Both high and low blood pressure can have serious health implications. To differentiate between these two conditions, one must first learn to identify their respective symptoms. Assessing symptoms, combined with taking accurate readings, will assist in the provision of effective treatment plans.
Recognising High Blood Pressure Symptoms
High blood pressure, also known as hypertension, is often referred to as a silent killer, as it frequently displays no clear symptoms. This makes regular blood pressure checks imperative for early diagnosis and prevention of serious health risks like strokes and heart attacks.
Hypertension is a condition characterised by consistently high blood pressure readings, typically above 130/80 mm Hg.
Though it often goes unnoticed, in severe cases, hypertension may induce some observable symptoms. These include:
- Severe headaches
- Fatigue or confusion
- Vision problems
- Chest pain
- Difficulty breathing
- Irregular heartbeat
For instance, a patient who reports a persistent headache alongside fatigue could be experiencing symptoms of elevated blood pressure, a condition that necessitates immediate medical intervention.
Identifying Low Blood Pressure Symptoms
On the other end of the spectrum, hypotension or low blood pressure also has its own unique set of symptoms. Low blood pressure is determined by a systolic reading that is consistently under 90 mm Hg, or a diastolic reading below 60 mm Hg.
Hypotension is persistent low blood pressure. It can often be asymptomatic, but may present symptoms in cases of sudden drops in blood pressure.
Symptoms of low blood pressure can vary greatly and may include:
- Dizziness or lightheadedness
- Fainting (syncope)
- Lack of concentration
- Blurred vision
- Nausea
For example, a patient who reports feeling lightheaded every time they stand up may be suffering from a form of low blood pressure known as postural or orthostatic hypotension. This type of hypotension occurs when blood pressure drops upon standing up or stretching.
Understanding Blood Pressure Regulation
Blood pressure regulation involves intricate interactions between various body systems to maintain adequate blood flow and prevent damage to organs.
The human body controls blood pressure using a complex network of hormones, nervous system functions, and various organs such as the heart, blood vessels, and kidneys. These systems work together to either constrict or dilate your blood vessels, changing the volume of blood your heart pumps, to maintain optimal blood pressure levels.
It is regulated by the baroreflex mechanism which uses baroreceptors, located in the aortic arch and carotid arteries, to sense changes in blood pressure.
If blood pressure becomes too high, the heart and blood vessels utilise these effects to lower pressure:
- The heart rate decreases
- Blood vessels expand or dilate (vasodilation)
- The volume of blood decreases due to less water reabsorption in the kidneys
Conversely, if blood pressure becomes too low, these mechanisms are used to increase pressure:
- The heart rate increases
- Blood vessels narrow or constrict (vasoconstriction)
- The volume of blood increases due to more water reabsorption in the kidneys
The process of blood pressure regulation is constant and dynamic, adjusting to the body's needs during different activities and at different times of the day.
Measurement and Risk Factors of Blood Pressure
Taking accurate blood pressure measurements and understanding the risk factors associated with hypertension are crucial competencies in nursing, particularly in intensive care settings. These skills ensure that you can effectively monitor and manage patient health, as well as intervene promptly when necessary.
How to Properly Carry Out Blood Pressure Measurement?
Properly measuring blood pressure is an essential skill for a nurse. This process requires a sphygmomanometer – a device that includes an air pump, a pressure gauge, and a cuff to wrap around the patient's arm.
A sphygmomanometer is the standard device used to measure blood pressure. It measures the force exerted by the blood on the walls of blood vessels.
When measuring blood pressure, follow these steps:
- Have the patient sit down and rest for at least 5 minutes before taking the measurement.
- Wrap the cuff of the sphygmomanometer around the patient's upper arm, at the level of the heart. The cuff should be snug but not too tight.
- Position the gauge of the sphygmomanometer so that it's at eye level. This allows for an accurate reading.
- Inflate the cuff to about 20 mm Hg higher than the patient's normal systolic pressure.
- Then, slowly release the pressure in the cuff while listening with a stethoscope for the korotkoff sounds.
- The pressure at which you first hear the patient's pulse beat is the systolic blood pressure.
- Continue to deflate the cuff. The pressure at which the pulse sound disappears is the diastolic blood pressure.
- Finally, slowly release the cuff entirely and note down both the systolic and diastolic blood pressure.
Suppose you're taking the blood pressure of a patient. You inflate the cuff to 150 mm Hg and then begin to slowly deflate it. At 120 mm Hg, you start to hear the patient's pulse beat. This is your systolic reading. As you continue, the sound disappears at 80 mm Hg, which indicates your diastolic reading. The blood pressure of this patient is therefore recorded as 120/80 mm Hg.
Hypertension Risk Factors in Intensive Care Nursing
In intensive care settings, several factors can increase the risk of hypertension. Being familiar with these risk factors allows for early detection and intervention, promoting better patient outcomes.
Hypertension risk factors can be divided into modifiable and nonmodifiable factors.
| Modifiable risk factors |
Nonmodifiable risk factors |
| Poor diet and nutrition |
Age |
| Lack of exercise |
Family history of hypertension |
| Excessive alcohol consumption |
Gender (men have a higher risk until age 55; women have a higher risk after menopause) |
| Tobacco use |
Race (African ancestry population have higher risk levels) |
Let's consider an example of a 70-year-old man admitted to intensive care following a surgical procedure. His diet is poor, he consumes alcohol regularly, and there is a history of hypertension in his family. He portrays several risk factors for hypertension: age, a family history of hypertension, poor diet, and excessive alcohol use. Extra diligence would be required in this patient's blood pressure management, and interventions such as dietary counselling and alcohol abstinence recommendation may mitigate the associated risks.
Importance of Monitoring Blood Pressure in Intensive Care Nursing
As an intensive care nurse, you are responsible for handling critically ill patients who are highly susceptible to drastic blood pressure changes due to their conditions or treatments. Consequently, stringent monitoring of blood pressure becomes a vital part of intensive care nursing.
Regular monitoring can help detect early signs of complications, guide therapeutic decisions, assess the effectiveness of treatments, and relay valuable information about the patient's circulatory system, organ perfusion, and fluid status.
Fluctuations in blood pressure in intensive care settings can be indicative of an array of clinical events:
- A sudden drop in blood pressure may signify septic shock or acute blood loss.
- High blood pressure might be linked to pain, anxiety, or a reaction to certain medications.
As an integral part of patient care, blood pressure monitoring needs to be accurate, consistent, and timely to ensure the best patient outcomes. Therefore, use the most appropriate and reliable tools and methods for the given patient and situation, always adhering to the best clinical practices. Handling and interpretation of blood pressure data should be done with the utmost attention to avoid any detrimental misjudgements.
Blood Pressure - Key takeaways
- Blood pressure is the force of blood pushing against the walls of the arteries as the heart pumps blood. It is measured as systolic and diastolic pressure.
- Normal blood pressure is defined as a systolic pressure below 120 mm Hg and a diastolic pressure below 80 mm Hg. High blood pressure, or hypertension, is typically above 130/80 mm Hg, and low blood pressure, or hypotension, is under 90/60 mm Hg.
- Lifestyle factors such as diet, exercise, body weight, and alcohol intake can influence blood pressure. High systolic blood pressure may indicate conditions like hypertension and increased risk of cardiovascular diseases.
- Symptoms of high blood pressure may include severe headaches, fatigue, vision problems, chest pain, and difficulty breathing. Low blood pressure may cause dizziness, fainting, lack of concentration, blurred vision, and nausea.
- Blood pressure is regulated by a complex network of hormones, nervous system functions, and various organs, and is influenced by the heart rate, blood vessel dilation or constriction, and the volume of blood. Blood pressure regulation employs mechanisms that respond to high or low pressure conditions.
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