Measuring Blood Pressure (BP)
Use the recommended technique at every BP reading to ensure accurate measurements and avoid common errors. Pay particular attention to the following:
- Measure BP with a regularly serviced mercury sphygmomanometer, or regularly validate your instrument against a mercury sphygmomanometer.
- At the patient's first BP assessment, measure BP on both arms. Thereafter, use the arm with the higher reading.
- In patients who may have orthostatic hypotension (e.g., the elderly, those with diabetes), measure BP in sitting position, and repeat after the patient has been standing for at least 2 minutes.
If possible, obtain BP measurements outside the clinic (by ambulatory BP monitoring or self-measurement), particularly for patients with any of the following:
- Unusual variation between BP readings in the clinic
- Suspected 'white coat hypertension' (e.g., clinic hypertension in a person without known cardiovascular risk factors)
- Hypertension that is resistant to drug treatment
- Suspected hypotensive episodes (e.g., in those who are elderly or have diabetes)
Interpret ambulatory BP profiles using standard reference values for daytime (awake), nighttime (asleep) and 24-hour means.
Diagnosis and Classification of Hypertension
- The diagnosis of hypertension should be based on multiple BP measurements taken on separate occasions.
- Recheck BP regularly, at intervals determined by both BP category and absolute cardiovascular risk.
Evaluation in Patients with Confirmed Hypertension
In all patients with hypertension, perform a clinical assessment (including a careful history, physical examination, initial investigations and further investigations as required) in order to:
- Identify all cardiovascular risk factors
- Detect end-organ damage and related or comorbid clinical conditions
- Identify causes of secondary hypertension
If secondary hypertension is suspected, consider specialist referral.
Assess absolute cardiovascular risk in all patients with hypertension in order to determine the optimal management plan.
Available absolute risk calculators may significantly underestimate cardiovascular risk in Aboriginal, Torres Strait Islander, Maori, and Pacific Islander peoples.
When to Intervene in Patients with Confirmed Hypertension
The decision to intervene and the development of a comprehensive management plan (including lifestyle advice and drug treatment) should be based on a thorough clinical investigation to identify associated clinical conditions and/or end-organ damage and assessment of absolute cardiovascular risk.
Advise lifestyle risk reduction for all patients, especially those with high-normal BP or hypertension.
Lifestyle Modification
Manage identified lifestyle risk factors in all patients, whether or not BP is elevated.
Advise patients to aim for healthy targets:
- At least 30 minutes of moderate-intensity physical activity on most, if not all, days of the week (daily total can be accumulated e.g., three 10-minute sessions). Advise patients of all ages to become more active.
- Smoking cessation. Refer patients to Quitline. Consider recommending nicotine replacement therapy and/or prescribing oral therapy (bupropion or varenicline) in patients who smoke more than 10 cigarettes per day and have no contraindications.
- Waist measurement <94 cm for men and <80 cm for women, body mass index <25 kg/m2. When recommending weight loss, advise patients on reducing kilojoule intake as well as increasing physical activity.
- Dietary salt restriction: ≤4 g/day (65 mmol/day sodium). Recommend low-salt and reduced-salt foods as part of a healthy eating pattern.
- Limited alcohol intake: ≤2 standard drinks per day for men or ≤1 standard drink per day for women.
When to Initiate Drug Treatment
Initiate antihypertensive drug treatment immediately in adults with any of the following:
- Grade 3 hypertension or isolated systolic hypertension with widened pulse pressure (systolic blood pressure ≥160 mmHg and diastolic blood pressure ≤70 mmHg)
- Associated conditions or evidence of end-organ damage (regardless of BP)
- Patients aged 75 years and older
- High absolute cardiovascular risk, as estimated using a risk calculator
Also consider drug therapy for:
- Patients with moderate risk of cardiovascular disease as estimated using a risk calculator
- Aboriginal and Torres Strait Islander adults
Explain the health implications of current risk and the potential benefits of the recommended treatment.
Initiating Drug Therapy
For patients with uncomplicated hypertension, begin antihypertensive monotherapy with any of these agents:
- Angiotensin-converting enzyme (ACE) inhibitors (or angiotensin II receptor antagonists)
- Calcium channel blockers
- Thiazide diuretics (consider for patients 65 years or older only)
For patients with comorbid or associated conditions, consider:
- The benefits, contraindications and cautions associated with specific agents (see Table 7 in the original guideline document)
- Potential drug–drug interactions
Begin antihypertensive therapy with the lowest recommended dose.
Treatment Targets
People with proteinuria >1g/day:
< 125/75
People with associated condition/s or end organ damage (coronary heart disease, proteinuria [>300 mg/day], stroke/TIA):
< 130/80
People with none of the following: Coronary heart disease, diabetes, chronic kidney disease, proteinuria (>300 mg/day), stroke/TIA:
< 140/90 or lower if tolerated
Attaining Targets
For all patients, arrange regular follow-up to reassess drug treatment and adjust the management plan to achieve targets for BP and other modifiable risk factors.
If the initial agent is not tolerated, change to a drug of a different class.
If target BP is not achieved, add a second low-dose agent from a different pharmacological class (see recommended combinations, page 23 in the original guideline document) before increasing doses. If target is not achieved and both drugs are well tolerated, increase dose/s.
Use up to four antihypertensive drugs in combination, if necessary to achieve target.
Avoid these combinations:
- Angiotensin-converting enzyme (ACE) inhibitor (or angiotensin II receptor antagonist) plus potassium-sparing diuretic
- Beta-blocker plus verapamil
Trial each regimen change for at least 6 weeks.
Non-responsive Hypertension
If BP remains elevated despite maximal doses of at least two appropriate agents, reassess for:
- Non-adherence
- Undiagnosed secondary hypertension
- Hypertensive effects of other drugs
- Treatment resistance due to sleep apnoea
- Undisclosed use of alcohol or recreational drugs
- Unrecognised high salt intake (particularly in patients taking ACE inhibitors or angiotensin II receptor antagonists)
- 'White coat' hypertension
- Technical factors affecting measurement
- Volume overload, especially with chronic kidney disease
