White Coat Hypertension
When blood pressure is recorded in a hospital set-up or in the physician’s clinic, there may be transient rise in BP in a normal individual. This is called white coat hypertension.
It is characterised by very high BP with neurological abnormalities, such as severe headache, loss of consciousness, convulsion, paraesthesia, transient disturbance of speech or vision, retinopathy, etc.
It is characterized by severe hypertension with diastolic BP >130 mmHg, associated with grade III or IV retinopathy (retinal haemorrhage or exudates and papilloedema) and renal failure or encephalopathy. If untreated, death occurs within months.
Treatment of Malignant Hypertension:
Slow, controlled reduction of BP over a period of 24–48 hours is ideal. (Rapid reduction is avoided as it reduces tissue perfusion and can cause cerebral damage including occipital blindness, may even precipitate coronary or renal insufficiency).
The treatment includes:
• Complete rest.
• Oral antihypertensive is sufficient to control BP.
• Sometimes IV or IM labetalol, IV glycerine trinitrate, IM hydralazine.
When there is no response to antihypertensive drugs, it is called refractory hypertension. The causes are:
• Nonadherence to drug therapy (most common cause).
• Inadequate therapy.
• Failure to recognize an underlying cause like renal artery stenosis or phaeochromocytoma.
Means failure to control BP with full doses of appropriate three drug regimen including a diuretic.
The following things should be carefully excluded:
• Improper BP measurement.
• Volume overload which may be due to excess sodium intake, renal disease or inadequate diuretic therapy.
• Inadequate dose, inappropriate combination of drugs or noncompliance.
• Whether patient is taking drugs like NSAIDs, steroid, oral contraceptive pills, ciclosproin, erythropoietin.
• Other secondary causes of hypertension.
• Associated conditions like obesity, excess alcohol intake etc.