Blood Pressure Guidelines and Hypertension Medications

In Canada, it’s estimated that one in five people are living with hypertension or high blood pressure. Hypertension is associated with an increased risk of stroke, heart disease, kidney damage and heart failure. Elevated blood pressure readings are directly correlated with cardiovascular mortality as the risk of the development of cardiovascular disease doubles each 20/10 mmHg increase in blood pressure. 

Given the prevalence of hypertension and the adverse outcomes associated with higher blood pressure readings, hypertension is also the most common condition for people taking medication in Canada. It’s thus very likely that you’ll be providing care to patients with hypertension, educating patients on hypertension or managing complications that have arisen due to poorly controlled hypertension. 

The role of nurses in hypertension care is all encompassing and includes responsibilities such as measuring blood pressure and providing patient education. Over time, the role of nurses in management of hypertension has evolved and now includes medication management, lifestyle interventions and ongoing monitoring and follow up. As such, a thorough understanding of blood pressure targets, medications used to manage hypertension and lifestyle interventions is vital. Given the prevalence of hypertension, a strong foundational knowledge on the management of hypertension is beneficial in everyday life as well. 

What is Hypertension?

Hypertension is characterized by consistently high blood pressure readings. Blood pressure is a measure of the force of the heart pumping blood throughout the body. This force is essential to distribute nutrients and oxygen throughout the body. However, it’s a fine balance, too much force can cause damage to the blood vessels and affect major organs.

Blood pressure is measured in mmHg. There are two components to a blood pressure reading. 

Systolic Blood Pressure (SBP):

• The pressure in the artery when the heart contracts. 
• This is the top number in a blood pressure reading

Diastolic Blood Pressure (DBP):

• The pressure in the artery when the heart relaxes. 
• This is the bottom number in a blood pressure reading.

Optimal blood pressure is considered to be a systolic reading below 120 and a diastolic reading below 80. However, the threshold for treatment varies depending on individual comorbidities and measurement technique.

What causes hypertension?

There are two main types of hypertension:

Primary (essential) hypertension:

• No absolute cause

• Most cases of hypertension are classified as this type.

• Risk factors include sedentary lifestyle, high sodium diet, smoking and obesity. 

Secondary hypertension:

• Caused by an identifiable cause such as pregnancy, diabetes or renal insufficiency. 

• Most cases of hypertension are classified as this type.

• This type of hypertension accounts for 20% of treatment resistant hypertension.

Diagnosis

Hypertension is diagnosed by blood pressure measurements. However, there is specific criteria that qualifies the diagnosis of high blood pressure and it’s not “one size fits all”. 

In general:

1. Automated blood pressure readings are preferred over non-automated blood pressure readings.  Automated blood pressure readings remove the likelihood of inaccurate readings due to error in technique. It also lowers the likelihood of a patient experiencing white coat hypertension.
   
   
2. SBP reading over 135 or a DBP over 85 is considered high when using an automated machine.
   
   
3. Unless in a hypertensive urgency or emergency, at least 2 readings should be taken before diagnosing hypertension. Blood pressure will normally vary throughout the day, multiple readings help ensure the diagnosis is accurate.

Hypertension will formally be diagnosed if they have:

1. A mean office blood pressure of ≥180/110
2. A mean office reading of ≥130/80 and they are diabetic or have chronic kidney disease
3. An elevated office reading of ≥135/85 and at home readings ≥135/85

Home blood pressure monitoring is encouraged as it can show if a person’s blood pressure was elevated because the reading was done in the office (known as white coat hypertension).

Management of Hypertension

In hypertension, upon initial diagnosis, healthy lifestyle interventions are optimized first. These interventions have been shown effective in both the management and prevention of hypertension and they should continue to emphasize the management of this chronic condition. 

Lifestyle interventions include the following: ‘

• Physical Activity: Exercising 30-60 minutes per day of moderate intensity 4-7 days a week
• Healthy BMI: Maintain or lose weight to attain a healthy BMI (18.5-24.9 kg/m2)
• Moderate Alcohol Intake: Limit the consumption of alcohol to 0-2 drinks/ day
• Healthy Diet: Eating a diet of low sodium, cholesterol and saturated fat. An increase in dietary potassium can be considered if there are no kidney problems.
• Smoking Cessation: Quitting smoking is recommended  

If lifestyle measures are non-sufficient, medications need to be initiated. One medication is not always enough to reach target blood pressures. Two or more agents can be used working together in different ways to meet blood pressure targets. Some medications will be used preferentially when a patient has compelling indications. 

Below is a summary of the medications commonly used in hypertension management and important considerations when initiating or monitoring these medications. 

Important notes:

• A lot of patients won’t reach blood pressure targets with one drug. Adding another drug is more effective than doubling the dose of one drug. 
• ACE inhibitors and ARBs are not used together due to an increased risk of side effects
• Recommended combinations are ACE Inhibitors/ ARBs with a CCB/ diuretic. 
• Beta blockers in combination with ACE inhibitors/ ARBs has not shown an important effect on blood pressure 
• A lot of combinations are available in a single pill combination which is important for adherence!

The Essential Role of Nurses in Management of Hypertension

Identification:

As nurses, you are on the floor and directly interacting with patients. You are also the healthcare professional that is responsible for blood pressure monitoring when a patient is admitted into a hospital or long-term care facility. As hypertension is a silent killer, patients may be unaware that they even have high blood pressure prior to being monitored in the hospital. Nurses are often the first to detect hypertension in patients.

This is why an understanding of what constitutes a high blood pressure reading is essential. With a strong understanding of hypertension, you can assess and flag elevated readings to the prescriber.  

Patient Education:

When it comes to hypertension, nurses often take the lead role in patient education. Healthy behavior interventions are the backbone for management of hypertension and nurses have a key role in providing this education to patients to empower them to undertake these lifestyle changes. 

Nurses are also the experts in blood pressure monitoring. Given that this is a medical condition that requires frequent at home monitoring, nurses often engage the patient on blood pressure monitoring devices and proper monitoring technique.

In addition to showing them how to use the machine, home monitoring patient education can include the following:    

• Rest for 5 minutes before taking a reading. Do not smoke or drink caffeine beverages half an hour before.
• Arm should be supported at heart level. Back should be supported and feet should be flat on the ground with legs uncrossed.
• Avoid speaking or moving when taking a reading.

Monitoring and Follow-up:

Hypertension is a chronic disease and will continue to need ongoing monitoring and follow-up. Nurses are perfectly poised and trained to provide management and follow-up to patients. 

As nurses are frequently interacting with patients, often they are the first to detect side effects experienced from blood pressure medications. 

Nurses can also build relationships with patients and regularly follow-up with patients regarding home monitoring, reinforce the importance of blood pressure goals and work to identify barriers to adherence. Suboptimal treatment regimens, poor adherence and drug interactions exacerbating the readings can be detected through ongoing monitoring and follow up. 

Conclusion

Hypertension is a disease that is characterized by elevated blood pressure readings. In order to lower the risk of stroke, heart disease and kidney damage, a lower blood pressure is targeted through healthy behavior interventions, medication management and close follow-up.

As nurses, you are the primary health care professional that measures blood pressure in patients and often the primary health care professional to identify hypertension in patients. You are also the health care professional likely to assess adherence, provide patient education and monitor efficacy.

A strong understanding of the management of hypertension is essential for you to fully optimize their role and improve outcomes in hypertension care.

Resources:

All the factual information in this post is supported by Hypertension Canada, a national non-profit organization dedicated to the prevention and control of hypertension.