Hypertension (Guidelines)

• Hypertension is usually asymptomatic; although, rarely, it can present as an emergency situation and must be treated immediately in these circumstances.
• Accelerated (or malignant) hypertension is a severe increase in blood pressure to 180/120mmHg or higher with signs of retinal haemorrhage and/or papilloedema. It is usually associated with new or progressive target organ damage. See below for referral criteria.

Risk Factors

• Age: BP tends to rise with advancing age
• Gender: Up to about 65 years, women tend to have lower BP than men. Between 65-74 years of age, women tend to have higher blood pressure.
• Ethnicity: People of black African and African-Caribbean origin are more likely to be diagnosed with hypertension.
• Genetic factors: A positive family history increases the risk of developing hypertension.
• Social deprivation: People from deprived areas are more likely to have hypertension than those from less deprived areas.
• Co-morbidities: Co-existing diabetes or kidney disease
• Lifestyle: Smoking, excessive alcohol consumption, excess dietary salt, unhealthy diet, obesity, lack of physical activity.
• Anxiety and emotional stress: Can raise BP due to increased adrenaline and cortisol levels.

How to measure BP in a clinic setting

1. The patient should be seated upright for 5 minutes with arm supported. Caffeine, exercise and smoking should be avoided for at least 30 minutes before the measurement.
2. Neither the patient nor the observer should talk during the rest period or during the measurement.
3. Confirm correct cuff size and remove any clothing covering the location of the cuff placement.
4. A validated and calibrated automatic device can be used if the patient is in sinus rhythm, but in atrial fibrillation, blood pressure must be measured manually.
5. At the first visit, record BP in both arms and use the arm that gives a higher reading for subsequent readings.
6. Ideally, three readings should be taken. The first reading should be discarded and the second and third readings averaged
7. If there are any postural symptoms, a sitting / standing BP should be measured. 

How to measure sitting / standing BP

1. In people with symptoms of postural hypotension (falls or postural dizziness), measure blood pressure with the person either supine or seated.
2. Measure the blood pressure again with the person standing for at least one minute before measurement.
3. If the systolic blood pressure falls by 20mmHg or more when the person is standing, measure subsequent blood pressures with the person standing.

How to perform home blood pressure monitoring (HBPM)

1. HBPM should be taken with a validated device.
2. The patient should avoid smoking, caffeine, or exercise within 30 minutes and ensure greater than 5 minutes of rest before blood pressure measurements.
3. The patient should sit upright with arm supported on a flat surface and feet on the ground, legs uncrossed.
4. The bottom of the cuff should be placed directly above the bend of the elbow
5. The patient should take two readings one minute apart in the morning before medication and in the evening before dinner for at least four days, but ideally seven days.
6. Discard the measurements on the first day and average the remaining measurements.
7. Threshold / targets for HBPM are 5/5mmHg lower than clinic values.

Sample Template: Home blood pressure monitoring form (NHS Highland intranet access required)

Emergency referral (same day)

• Clinic BP of 180/120mmHg or higher with:
  • Signs of retinal haemorrhage or papilledema 
  • AND/OR life-threatening symptoms, such as new onset confusion, chest pain, signs of heart failure, or acute kidney injury
• Suspected phaeochromocytoma (ie. labile or postural hypotension, headache, palpitations, pallor, abdominal pain or diaphoresis).

Non-emergency referral

• Adults aged under 40 with hypertension:
  Consider referral to renal physicians via usual pathways, eg, SCI referral or phone.
• Resistant hypertension (see: Definitions):
  Consider referral to renal physicians or diabetes via usual pathways, eg, SCI referral or phone.
• People who are pregnant with hypertension:
  Refer to Obstetrics via usual pathways, eg, SCI referral or phone.

Initial Investigations

• FBC, U&Es, LFTs, HbA1c, Lipids, Urinalysis
• ECG
• Assess for signs of target organ damage
• Calculate cardiovascular risk assessment
• Patients aged under 40 should also be investigated for:
  • Low potassium and high sodium (hyperaldosteronism)
  • 24 hour urinary catecholamines (phaechromocytoma)
  • Serum renin and serum aldosterone (the lab requires prior warning for this)

Antihypertensive choice

See BNF or manufacturer's information for full prescribing details.

Flowchart adapted from NG136 and SIGN 149

• About 25% of patients will achieve satisfactory BP control with one drug; however, many will require drugs from up to three different groups.
• Consideration should be given to using two or more antihypertensive agents, in half to standard doses, to achieve additive blood pressure lowering whilst minimising the averse effect profile.
• ACEi/ARB: May be indicated as first-line therapy in CKD with ACR ≥30 mg/mmol. In those of black African or African-Caribbean descent, consider an ARB instead of ACEi. Avoid the combination of an ACEi and and ARB. Use caution when combining ACEi or ARBs with spironolactone due to the risk of hyperkalaemia. Cautioned in women of childbearing potential and contraindicated in pregnancy.
• Beta-blockers: May be indicated as first-line therapy in ischaemic heart disease.

Monitoring

Medicine Sick Day Rules

The Sick Day Rule cards have been produced to aid patients in understanding which medicines they should stop taking temporarily during illness (e.g. vomiting, diarrhoea and fever) that can result in dehydration

See: Medicines Sick Day Rules Card

Woman of childbearing potential:

• If an ACEi/ARB is commenced, advise that these have an increased risk of congenital abnormality, if taken in pregnancy.
• Consider co-prescribing contraception, if appropriate.

Woman is planning pregnancy or becomes pregnant:

• ACEi/ARB should be stopped and, if appropriate, an alternative commenced.
• Thiazide or thiazide-like diuretics: there MAY be an increased risk of congenital abnormalities and neo-natal complications if taken in pregnancy, so alternatives should be sought.
• Alternative antihypertensives considered safe in pregnancy include methyldopa, labetalol, and nifedipine.

Referral

• For women with pre-existing hypertension who are planning pregnancy: consider referral to the high risk maternal medicine clinic.

See: 

• NHS Highland: Hypertension in pregnancy (NHS Highland intranet access required)
• British Medical Bulletin: The management of hypertension in women planning for pregnancy
• NICE NG133: Hypertension in pregnancy 

Statins

If diabetic, 10 year risk of CVD is ≥20%, or a strong family history of premature vascular disease, recommend lipid-regulating therapies.

• Lipid lowering therapy in the prevention / treatment of atherosclerosis (Guidelines)

Antiplatelets

Use in secondary prevention only. 

• Acute treatment and secondary prevention of transient ischaemic attacks (TIA) and ischaemic stroke (Guidelines)
• Secondary prevention post myocardial infarction (Guidelines)

Adults without a diagnosis of hypertension

It is recommended that a CVD risk assessment is offered at least once every five years in adults over the age of 40 with no history of CVD, familial hypercholesterolaemia, CKD or diabetes and who are not being treated to reduce blood pressure or lipids.

Adults with hypertension

Provide an annual review for adults with hypertenson. Key information:

• Explore risk factors: family and personal history of hypertension, CVD, stroke, renal disease, hypercholesterolaemia, diabetes; smoking history; alcohol consumption; dietary / salt intake; physical activity
• Confirm current / past antihypertensive medication, effectiveness, side effects, and compliance
• Take height / weight
• Measure BP
• Palpate pulse
• Check renal function (U&Es and ACR)
• Assess cardiovascular risk 
• Consider discussing erectile dysfunction and sleeping issues, if appropriate

The most common use of Connect Me is within primary care, where GPs and practice nurses enrol patients with hypertension or suspected hypertension.

Connect Me contacts the patient twice a day to ask for blood pressure readings.  The patient takes their own blood pressure and sends the reading back to Connect Me.  If their BP reading is concerning, Connect Me may respond with some advice about what they should do.

With Connect Me, patients have a choice of communication methods depending on the technology they have access to or are most comfortable with:

• Online: Connect Me sends emails and the patient logs into the Inhealthcare patient website to respond with their readings, or they can use the free My Inhealthcare app
• Text messages: Connect Me sends text messages and patients respond by text
• Automated telephone calls: Connect Me phones the patient at set times and asks for their readings. They respond using the phone's number pad.

For diagnosis of high blood pressure, patients will be asked for readings every day. Once diagnosed they will only be asked for readings on two days a week or possibly just one day a month.

The patient's GP will be sent a report of the patient's BP readings at regular intervals, so they can assess whether the patient has high blood pressure or can check whether their medication is working effectively, without the patient having to make repeated visits to the surgery.

Connect Me resources for clinicians and patients: Connect Me (NHS Highland intranet access required)

Contact information: nhsh.connectme@nhs.scot

In Highland, most of our Connect Me services are provided by the Inhealthcare remote health monitoring platform. 

• National Blood Pressure Service

Dietary advice:

• Maintain a healthy diet (Eatwell Guide). Include plenty of fruit and vegetables, oily fish, nuts, seeds, and fibrous foods (i.e. wholemeal bread, oats, peas, beans, lentils, high fibre breakfast cereals).
• Eat when physically hungry and stop when full; recognise emotional eating.
• Restrict salt to less than 6 grams/day.
• Restrict caffeine consumption to fewer than five cups of coffee or tea per day.

Lifestyle advice:

• Aim for a healthy BMI: between 20 to 25 kg/m². Lose weight if obese.
• Perform regular aerobic exercise, that is, 30 minutes of moderate dynamic exercise on 5 to 7 days per week.
• Consider stopping smoking.  
• Reduce alcohol intake to recommended levels (less than 14 units per week for men and women).

Referral Information

• Smoking cessation (Guidelines)
• Weight and health (Guidelines)
• Community Link Workers - refer via Elemental's social prescribing software within Vision. See: Social prescribing guidelines

Definitions:

High risk: History of haemorrhagic/ischaemic stroke, TIA, Diabetes, CKD, target organ damage, known CVD

Target organ damage:

• Heart failure
• Established coronary heart disease
• Stroke or TIA
• Peripheral Arterial Disease
• Abnormal renal function (raised creatinine or ACR/PCR)
• Hypertensive or diabetic retinopathy
• LV hypertrophy on ECG or ECHO

Postural hypotension: A sustained reduction of systolic blood pressure of at least 20mmHg or diastolic blood pressure of 10mmHg within 3 minutes of standing, or of tilting the body (with the head up) to at least a 60° angle on a tilt table

Resistant hypertension: Blood pressure that is not controlled to goal despite adherence to an appropriate regimen of three antihypertensive drugs of different classes (including a diuretic) in which all drugs are prescribed at suitable antihypertensive doses and after white coat effect has been excluded. Blood pressure that requires at least four medications to achieve control is considered controlled resistant hypertension

Masked hypertension: Blood pressure measurements are normal in clinic but are higher when taken outside the clinic using average ABPM/HBPM.

White coat hypertension: Blood pressure that is unusually raised during consultations with clinicians but is normal when measured in ‘non-threatening’ situations. It occurs in about 15-30% of the population.