By Stephen Adams
Currently, anyone suspected of having high blood pressure is diagnosed by a GP with an inflatable arm cuff. Doctors then call the patient back for additional readings, but these are always taken at their surgery or in hospital.
New draft guidance to be published today by the National Institute for Health and Clinical Excellence (Nice) says as many as one in four people experiences a surging pulse rate on entering a GP’s surgery.
This nervous response, termed “white coat hypertension”, can significantly raise blood pressure readings and many people are being misdiagnosed as a result.
To counter this, Nice is recommending that doctors do not rely solely on readings taken in their own surgeries. After the initial assessment, a patient should be sent home and asked to wear an ambulatory blood pressure monitoring (ABPM) device.
This comprises an inflated arm cuff, similar to those used in surgeries, which takes spot readings at intervals over a 24-hour period.
Prof Bryan Williams, from Leicester University, who led the development of the new guidance, said: “This new approach would not only improve diagnosis but would ultimately be cost-saving for the NHS.”
More than 8.5 million people are registered as having high blood pressure. People with the condition are three times more likely to develop heart disease and suffer strokes as people with normal blood pressure and twice as likely to die from these.
Patients are often put on drugs to lower their blood pressure, such as beta-blockers and angiotensin-converting enzyme (ACE) inhibitors. In 2008, the NHS in England spent £83 million on beta-blockers alone.
The drugs can have serious side effects. For example, ACE inhibitors can cause blood pressure to drop to dangerously low levels and result in kidney problems.
Nice’s guidance notes: “White coat hypertension is reported to occur in as many as 25 per cent of the population, especially where their blood pressure is close to the threshold for diagnosis. It is more common in pregnancy and with increasing age.”
This suggests that as many as 2 million people may have been wrongly diagnosed simply because they were nervous when they went into the surgery.
Prof Williams added that the new guidance would allow doctors to get the correct diagnosis more often, but warned that surgeries and clinics would not have sufficient stocks of the equipment at the start.
The Blood Pressure Association, which has been campaigning for the change for years, welcomed the move. Prof Gareth Beevers, a trustee of the charity, said the guidance should be backed up with money “to ensure ambulatory monitors are more widely available”.
But Dr Clare Gerada, chairman of the Royal College of GPs, questioned whether the new approach would be significantly more accurate.
She said: “If we were looking at lifelong treatment or uncertain diagnosis, then this device might be useful, but for the majority of patients we would take three readings anyway before starting treatment.”
Nice officials said the guidelines, which it has put out for consultation, would “significantly change the way high blood pressure is diagnosed and subsequently treated”.
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