25/03/2025
KIDNEY BLOOD TEST (GFR) Special Newsletter March 2025
There have been several concerns raised here at the surgery over the last few months regarding the interpretation of kidney blood tests.
Patients who are accessing the NHS APP are now able to look at their results (and the laboratory comments), and it appears that the comments are often causing anxiety, distress, and unfortunately, the blame is being put on the GPs. To try and put the kidney bloods (GFR - Glomerular Filtration Rate) into perspective, I think the following may be of use:
The GFR is essentially an indirect way of measuring and monitoring how well one's kidneys are working. Until a few years ago, it was agreed that anyone who filtered more than 60mls in an hour (in other words, 1 ml a minute or more) was considered normal. A few years ago, and I believe it was a knee jerk response to dehydration in some nursing homes not being picked up soon enough, the goalposts were changed from 60mls per hour to 90mls per hour. Not many perfectly healthy patients get the normal result of more than 90. I did an audit of the last 50 patients here at the surgery who had kidney blood tests within a routine blood test, and it appears that more than 75% would have a result less than 90.
If a GFR is less than 90, this is most of the time not any cause for concern. (The rates of the GFR in my short audit were between 23 and 89). The current guidance suggests that if someone’s GFR is stable, then this should be repeated every 6 to 12 months. Should the GFR have decreased significantly, it is suggested to repeat the blood test in three months and see if there's anything we can change to improve the kidney blood test. The most common culprits of a lower GFR are some of the blood pressure tablets, tablets for heartburn and reflux, and the anti-inflammatories, most notably ibuprofen and its cousins. Most patients' kidneys remain stable. And from a medical point of view, we are more interested in the pattern than what the specific measurement is.
Regarding the patients who have called in being angry with GPs for “not telling them they had kidney disease”, we would like to reassure you that all the results are reviewed, and the clinical team then make sensible decisions. Contacting three quarters of our patients whose GFR is slightly low will entail up to 3,000 telephone calls a month. Obviously, this is not possible. I hope the above explains and clarifies the significance of what is described in the report as” chronic kidney disease - CKD”.
Should you have any specific concerns, please contact the surgery in a routine fashion, and we would be happy to discuss your concerns in person. I hope with this, we can put the concerns raised from a low GFR to bed.
Blood Hub, Bodmin: If you are due or are asked to book a routine blood test we may ask you to book at the Blood Hub in Bodmin. You are likely to get an appointment quicker, also if we don’t use it we’ll lose it, and finally this free’s up our nurses time for earlier appointments for other services. The link to book is Community Diagnostic Hub. You will need a mobile ‘phone number to book. The reception team are happy to help if you don’t have online access or a mobile number.
If you have any feedback about absolutely anything, please feel free to get in touch with the Practice Manager – Amanda –Please call or email ciosicb.lostenq@nhs.net.