Category: Topic Loops

Giant cell arteritis

Introduction

Giant cell arteritis:

  • A disease which occurs in people over 50 yrs and more often much older – it is exceptionally rare in younger people
  • Causes inflammation of medium sized arteries e.g. vertebral, carotid ophthalmic arteries – cause is unknown (see image below)
  • May present suddenly with severe headache or stroke, or with a more chronic illness developing over weeks or even months
  • Often affects the arteries in the head, particularly the temples, so can also be called Temporal Arteritis
  • Inflammation may damage arteries causing them to block or clots form on damaged lining of the artery (intima) which can embolise to the brain or other organs
  • Usually associated with a very high ESR – i.e. >60mm per hour
  • It’s serious and needs urgent treatment
  • Should be confirmed with a biopsy of an artery – most often the temporal artery – this can be done under local anaesthetic as a day case
  • The biopsy will become uninformative within days of starting treatment so should be done early.
Giant cell arteritis
Giant cell arteritis. (Courtesy of Dr Colin Smith, Edinburgh)

How are SIGN guidelines produced?

The Scottish Intercollegiate Guidelines Network (SIGN) develops evidence based clinical practice guidelines for the National Health Service (NHS) in Scotland.

Guidelines are usually written by a multidiciplinary group who will:

  • Decide on questions/issues/scope
  • Search for evidence
  • Appraise evidence
  • Write draft guideline
  • Consult widely
  • Write final guidelines
  • Publish and disseminate widely
  • Encourage use in everyday practice

Other organisations, including National Institute for Health and Clinical Excellence (NICE) and the Royal College of Physicians Intercollegiate Stroke Working Party produce evidence based guidelines in the UK.

Examples of evidence based stroke guidelines

Stroke Guidelines in the UK. These are updated and may change.

The Scottish Intercollegiate Guidelines Network (SIGN) develops evidence based clinical practice guidelines for the National Health Service (NHS) in Scotland.

NICE guidelines cover

The NICE (National Institute for Health and Clinical Excellence) also produce guidelines relevant to the whole of the UK. Those relevant to stroke are:

Royal College of Physicians guidelines cover

The Royal College of Physicians Intercollegiate Stroke Working Party also produce national clinical guidelines for stroke.

Guidelines quiz

For information on grades and levels of evidence see the Additional Information box on the right.

  • The best guideline statements are based on reliable evidence from research.
  • This should ensure that patients managed in accordance with guidelines will have better outcomes than those who are not.
  • However, clinical judgement is needed in applying evidence and guidelines to individual patients.

Evidence based guidelines

What are Evidence based guidelines?

  • Evidence-based guidelines are collections of statements which recommend how patients with certain conditions should be treated. For example, there is an evidence-based guideline which states that patients with ischaemic stroke should receive 300mg of aspirin within 48 hours.
  • Each of the statements within a guideline are based on evidence. The strength of the evidence supporting each statement will be given. The highest strength of evidence comes from well-conducted systematic reviews and RCTs, and is called ‘Grade A’ evidence (see Additional Information box for more information). For example, there is an evidence based guideline which states that anti-embolism stockings should not be used in stroke patients; this is based on Grade A evidence.
  • Evidence-based guidelines will also contain clear recommendations for future research to fill the gaps in the evidence-base.
  • Evidence-based guidelines may also include suggestions relating to the implementation of the guidelines.
  • Although most patients should be treated in line with the relevant guideline statements, individual factors will determine that some patients should be treated in a different manner.
  • The quality of evidence is described according to a number of different levels (see Additional Information box for further information).

How do I search for the evidence I need?

Knowledge Network

  • On the Knowledge Network you can enter your search terms into the search box on the home page.
  • If you want to combine several search terms you can do this using the word “AND” in the search box
  • For example, if you have a question about the best amount of physiotherapy after stroke, you would enter: Stroke AND Physiotherapy AND amount

Knowledge Network website screenshot

  • The search results will have a series of filters, so you can select the type of evidence you wish to view. However if you are looking for systematic reviews, you are better to use the Cochrane Library or DORIS.

Cochrane Library

  • If you want to combine several search terms within the Cochrane Library, it is easiest to do this using an advanced search
  • Your search for evidence about the best amount of physiotherapy after stroke would look like:

Cochrane library advanced search website screenshot

  • At the top of the search results you will see the number of Cochrane reviews, other reviews and clinical trials.

Cochrane library search results website screenshot

  • You can browse through the titles for the evidence you need.

DORIS

  • Evidence on DORIS has to be browsed using lists of topics and / or interventions.
  • DORIS has a step by step guide to using DORIS
  • For the question about the best amount of physiotherapy after stroke, you might choose to browse by intervention only – selecting ‘physiotherapy’ and ‘intensity’:

Doris search website screenshot

  • The search results are categorised by the type of evidence, so you can select the evidence which you require. Generally it is most helpful to start by looking at Guidelines, then Cochrane reviews, other reviews etc – as this provides you with the ‘most’ synthesised information first.

Doris search results website screenshot

Where do I find the evidence I need?

Knowledge Network

  • The Scottish Knowledge Network, provided by NHS Education for Scotland, should give you access – or links – to all the sources of evidence which you need.
  • The Knowledge Network provides you with a search engine which lets you search everything within the Knowledge Network library.
  • It also gives you links to other evidence sources, such as the Cochrane library.
  • Best practice statements are listed within the Knowledge Network.

Cochrane Library

DORIS

  • DORIS is the Database Of Research In Stroke
  • DORIS has been supported by the Scottish Government’s National Advisory Committee for Stroke to give you easy access to high quality stroke evidence
  • DORIS gives you easy access to guidelines, Cochrane reviews, other systematic reviews and randomised controlled trials.

Evidence into practice

  • A high quality systematic review of RCTs may provide a body of evidence which is sufficient to support clear recommendations for clinical practice.
  • Sometimes there is insufficient RCT research to support clear recommendations for clinical practice.
  • When there is a limited amount of high quality evidence available, then it is appropriate (and necessary) to use other types of research and information to guide treatment decisions
  • When there are variations in current practice and a limited evidence base, best practice statements may provide the best summary of evidence
  • Best practice statements attempt to incorporate professional consensus in the absence of a rigorous evidence base

Cochrane reviews

  • The Cochrane Collaboration aims to help healthcare providers, policy makers, patients, their advocates and carers make well-informed decisions about human healthcare
  • The Cochrane Collaboration prepares, updates and promotes the accessibility of Cochrane systematic reviews.