Hypertension or high blood pressure is very common and affects 16 million people in the UK. Often called the silent killer it has little effect for many years but can then cause heart attacks and strokes and is a major cause of death. It is very easy to measure and in most patients easy to manage in primary care with one or two tablets a day.

Anaesthetists have been concerned since the 1950s when a number of studies suggested that patients with high blood pressure had a higher death rate undergoing general anaesthesia. Further research this millennium has questioned whether the risk is greater and also whether treating blood pressure in the perioperative period is beneficial, but there is no consensus and the result is 100 patients a day have their operations cancelled due to high blood pressure. This is a national disgrace which means that the equivalent of an entire hospital lies idle in the NHS every day because high blood pressure has not been picked up and dealt with before the day of surgery.

Anaesthetists have ridden to the rescue and the Association of Anaesthetists of Great Britain and Ireland and the British Hypertension Society have now published national guidelines which you can read at http://onlinelibrary.wiley.com/doi/10.1111/anae.13348/full. If implemented properly they could prevent all cancellations on the day for preplanned surgery,

The recommendations are simple and pragmatic: a general practitioner should only refer a patient for surgery when he or she includes a blood pressure taken within the last six months. Older patients should be screened for high blood pressure and younger patients will normally have a basic medical before a GP refers so this is merely a matter of including data that the GP has in their letter. The blood pressure should be below 160 systolic (the higher reading) and 100 diastolic (the lower reading which we write as 160/100. If it is higher than this then the GP should manage the blood pressure before referral. But importantly if it is lower the blood pressure should not be taken again by either the surgeon nor the preassessment clinic nor indeed in hospital before the anaesthetic. The reason for this is the blood pressure often rises due to anxiety and patients with an acceptable blood pressure may have unacceptably high readings due to the so-called white coat syndrome when they are admitted.

It will be a challenge to implement this sensible and money-saving plan and I believe patients can help. So what should patients do about high blood pressure? Here are my simple recommendations:

1 everybody over say 45 should have their blood pressure measured and if it is above 140/90 on a single reading I recommend you buy a simple home blood pressure machine. Omron make very reliable machines available from Boots (I dont own shares in either!!). Take your blood pressure every couple of days at different times. Record the date and time, what you are doing and the two numbers. If your blood pressure goes up and down with some readings below 140/90 (ie BOTH readings below these levels) do nothing, but if it is consistently above this talk to your GP about taking tablets. These can bring your risk of heart attacks and strokes back to almost normal

2 everybody who has high blood pressure should I believe have a machine and take their own blood pressure because it is far more reliable than the blood pressure taken at the GPs and many practices are happy to be sent readings and avoid the cost and disruption of further appointments

3 if you are referred to hospital for an operation remind your GP to include your blood pressure, which will of course e below 160/100!! Take your notebook or spreadsheet with your readings to hospital and if your surgeon or preassessment clinic try to take your blood pressure tell them that this is no longer recommended. If anybody tries to cancel your operation show them your notebook, remind them of the recommendations and you won’t be cancelled.

About the author

Dr Aubrey Bristow is a consultant anaesthetist in central London. These articles are his personal views and reflect individual issues of interest to patients. They are not a comprehensive review of the subject nor a substitute for a consultation with your anaesthetist.