Podcast - Rock solid advice: NICE on renal stones

26/02/2025 9 min

Listen "Podcast - Rock solid advice: NICE on renal stones"

Episode Synopsis

The video version of this podcast can be found here: ·      https://youtu.be/xPm1G9aiSv8This episode makes reference to guidelines produced by the "National Institute for Health and Care Excellence" in the UK, also referred to as "NICE". The content on this channel reflects my professional interpretation/summary of the guidance and I am in no way affiliated with, employed by or funded/sponsored by NICE.NICE stands for "National Institute for Health and Care Excellence" and is an independent organization within the UK healthcare system that produces evidence-based guidelines and recommendations to help healthcare professionals deliver the best possible care to patients, particularly within the NHS (National Health Service) by assessing new health technologies and treatments and determining their cost-effectiveness; essentially guiding best practices for patient care across the country.My name is Fernando Florido and I am a General Practitioner in the United Kingdom. In this episode I go through the NICE guideline on “Renal and ureteric stones: assessment and management” or NG118, focusing on what is relevant to Primary Care only. I am not giving medical advice; this video is intended for health care professionals, it is only my summary and my interpretation of the guidelines and you must use your clinical judgement.   Disclaimer:The Video Content on this channel is for educational purposes and not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read or seen on this YouTube channel. The statements made throughout this video are not to be used or relied on to diagnose, treat, cure or prevent health conditions. In addition, transmission of this Content is not intended to create, and receipt by you does not constitute, a physician-patient relationship with Dr Fernando Florido, his employees, agents, independent contractors, or anyone acting on behalf of Dr Fernando Florido.There is a podcast version of this and other videos that you can access here: Primary Care guidelines podcast:  ·      Redcircle: https://redcircle.com/shows/primary-care-guidelines·      Spotify: https://open.spotify.com/show/5BmqS0Ol16oQ7Kr1WYzupK·      Apple podcasts: https://podcasts.apple.com/gb/podcast/primary-care-guidelines/id1608821148 There is a YouTube version of this and other videos that you can access here: The Practical GP YouTube Channel: https://youtube.com/@practicalgp?si=ecJGF5QCuMLQ6hrk The Full NICE guideline on Renal and ureteric stones: assessment and management can be found here:·      https://www.nice.org.uk/guidance/ng118 Intro / outro music: Track: Halfway Through — Broke In Summer [Audio Library Release] Music provided by Audio Library Plus Watch: https://youtu.be/aBGk6aJM3IU Free Download / Stream: https://alplus.io/halfway-through  TranscriptIf you are listening to this podcast on YouTube, for a better experience, switch to the video version. The link is in the top right corner of the video and in the episode description.Hello and welcome, I am Fernando, a GP in the UK. Today, we are looking at the NICE guideline on renal stones, or NG118, focusing on what is relevant in Primary Care only. Right, let’s jump into it.And before we get started on the NICE guideline itself, let’s have a quick overview of the clinical presentation. Patients with renal stones often present with:Severe, colicky flank pain that can radiate to the groin and genitals.Nausea and vomiting – which are common due to the intensity of the pain Lower urinary tract symptoms – like urgency, frequency, or dysuria andHaematuria – which can be visible or invisible. And if we suspect renal stones we would normally check urinalysis to test not only for invisible haematuria but also for possible signs of infection like leucocytes and nitrites.So, when is immediate referral to the emergency department necessary? We should do just that if the patient has:Fever or signs of sepsis like tachycardia, hypotension, or being systemically unwell.Renal impairment or anuria which would suggest obstruction, which is a urological emergency andUncontrolled pain or vomiting as these patients will need urgent care.On the other hand, we will consider non-urgent referral and investigations if we suspect renal stones because of milder but persistent symptoms or a previous history of recurrent stones. But now, let’s tackle a question: Why does renal colic cause such severe, colicky pain that radiates to the groin and genitals?There are three reasons:First, when a stone obstructs the ureter, it causes sudden distension and spasmodic contractions of the ureteric smooth muscle, which leads to that classic, severe, colicky pain.The pain can be a visceral pain from uretericl distension, which is poorly localized and felt deep in the flank and abdomen or it could be a somatic pain, when the stone irritates the bladder or urethra, leading to sharp, localised pain in the groin or perineum. And finally The referred pain is due to the fact that the ureter shares sensory innervation with the T10–L2 spinal segments, which also supply the flank, lower abdomen, groin, and genitals. And here is one final Clinical Clue: if the pain starts in the flank, moves to the lower abdomen, and then radiates to the groin or genitals, it’s a strong indicator of a stone migrating through the ureter.Now that we have reviewed the clinical presentation, let’s start the review of the NICE guideline itself.In terms of diagnostic imaging, limited evidence shows that MRI, ultrasound and plain abdominal X-rays were not as good as non-contrast CT for detecting renal and ureteric stones. CT is more expensive than ultrasound or a plain abdominal X-ray but the extra cost is likely to be outweighed by avoiding additional investigations when a first test misses the diagnosis. So, a low-dose non-contrast CT should be offered urgently, that it within 24 hours of presentation, to adults with suspected renal colic. However, for pregnant women and children, in order to minimise radiation, an urgent ultrasound scan should be offered instead. If there is still uncertainty about the diagnosis after ultrasound, for children and young people, a low-dose non-contrast CT can still be considered.Why do we need the imaging urgently, that is, within 24h? Well, NICE says that the reason is  because there are occasions where renal colic can cause renal function to decline quickly, so an early diagnosis is really important here. For pain management, we will offer a non-steroidal anti-inflammatory drug (NSAID) by any route as first-line treatment. This is because evidence shows that these drugs are the most effective compared with opioids, antispasmodics and paracetamol. Most studies used intravenous or intramuscular NSAIDs whereas oral or rectal NSAIDs are more common in the UK. However, due to insufficient evidence supporting any specific route, NICE did not recommend a particular method of administration.If NSAIDs are not enough or they are contraindicated, the next step would be paracetamol. Most of the evidence is based on intravenous paracetamol, commonly used in secondary care. However, even though NICE specifically recommends the intravenous route, in primary care, we would normally use the oral route.We can consider opioids if both NSAIDs and intravenous paracetamol are contraindicated or are not giving sufficient pain relief but there are concerns about misuse and dependency. NICE advises against antispasmodics, as they offer no benefit over NSAIDs. Additionally, in studies, they were administered intravenously, which increases the risk of adverse events and needs intensive monitoring.In terms of combination treatments, people with recurrent stones may already self-manage with both oral paracetamol and NSAIDs.  There is some evidence showing benefit of a combination of NSAIDs and oral paracetamol without an increase in adverse events. However, there was no strong evidence for any of the combination treatments so they are not routinely recommended over the step-wise approach.In terms of metabolic testing, for adults we will measure serum calcium and, if it can be obtained, we will arrange stone analysis. However, children should be referred to a paediatric nephrologist or urologist for this assessment.In terms of preventing recurrence, we will give the following advice:adults should drink 2.5 to 3 litres of water per day, and children and young people (depending on their age) 1 to 2 litresthey should add fresh lemon juice to drinking water. This is because lemon juice is rich in citrate, which can help prevent stone formation by binding to calcium and reducing calcium oxalate crystallization. It also alkalinizes the urine, making the environment less favourable for the formation of certain types of kidney stones, such as uric acid and cystine stones. And finally, by making water more palatable, it also encourages a higher fluid intake.We should also advise avoiding carbonated drinks. This is because many carbonated drinks, especially colas, contain phosphoric acid, which can lower urinary pH and promote the formation of calcium phosphate and uric acid stones. In addition, sugary sodas, can increase urinary calcium excretion and decrease citrate levels, both of which also contribute to stone formation. We will also recommend reducing salt intake. This is because excess sodium increases calcium excretion in urine which promotes calcium oxalate and calcium phosphate stone formation. Furthermore, a high salt intake can cause dehydration and a more concentrated urine, which can increase the risk further.And finally, we will not restrict dietary calcium, but recommend maintaining a normal calcium intake. And you could ask yourself, why maintain a normal calcium intake instead of restricting it? Well, contrary to what might seem logical, reducing calcium intake does not prevent renal stones and can actually increase the risk. The reason is that calcium from food binds with oxalate in the gut, preventing oxalate absorption into the bloodstream, reducing the risk of calcium oxalate stones, the most common type of kidney stone. Additionally, inadequate calcium intake can lead to bone demineralisation and an increased risk of osteoporosis.The actual management of renal stones corresponds to secondary care and the treatments include both medical and surgical approaches, including shockwave lithotripsy. Examples of medical treatment include the use of alpha-blockers, potassium citrate and thiazides.And that is it, a review of the initial assessment and management of renal stones in Primary Care. We have come to the end of this episode. Remember that this is not medical advice but only my summary and my interpretation of the guidelines. You must always use your clinical judgement. Thank you for listening and goodbye.

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