{"id":201,"date":"2018-04-23T12:05:31","date_gmt":"2018-04-23T12:05:31","guid":{"rendered":"http:\/\/edren.org\/ren\/?page_id=201"},"modified":"2022-11-11T13:33:07","modified_gmt":"2022-11-11T13:33:07","slug":"stone-disease","status":"publish","type":"page","link":"https:\/\/edren.org\/ren\/handbook\/unithdbk\/individual-kidney-diseases\/stone-disease\/","title":{"rendered":"Stone disease"},"content":{"rendered":"

Recurrent stone\u00a0formation is common, but people who have frequent early recurrences should be screened for risk factors.<\/p>\n

Check:<\/p>\n\n\n\n\n\n\n\n\n
Blood<\/span><\/strong><\/td>\nRenal function
\nCa and PO4
\nUric acid
\nHCO3<\/td>\n<\/tr>\n
Urine<\/span><\/strong><\/td>\nInfection<\/p>\n

Request 24h urine collections for ‘stone screen’ to check volume, calcium, oxalate, Na, urate, cystine.\u00a0 Note that creatinine and protein need to be requested separately. This screen requires two separate 24 hour collections: one in a plain container and one in an acidified container.\u00a0 See Edinburgh Lab Medicine<\/a> pages.<\/td>\n<\/tr>\n

Stone<\/span><\/strong><\/td>\ndon’t forget to analyze the stone itself<\/td>\n<\/tr>\n
Family history<\/span><\/strong><\/td>\nhypercalciuria, medullary sponge kidney, distal RTA, Dent’s disease<\/td>\n<\/tr>\n
Drug history<\/span><\/strong><\/td>\noccasionally stones formed from drugs (including ephedrine)<\/td>\n<\/tr>\n
Dietary assessment<\/span><\/strong><\/td>\nimportant.\u00a0 See Diet<\/span><\/a>.<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

As for protein, urinary calcium can be measured as a ratio with creatinine, instead of a 24h clearance:<\/p>\n\n\n\n\n\n\n
\n
Ca\/Creat ratio<\/span><\/strong><\/div>\n<\/td>\n
\n
Comment<\/span><\/strong><\/div>\n<\/td>\n
Oxalate\/Creatinine<\/span><\/strong><\/td>\n<\/tr>\n
\n
< 0.6<\/div>\n<\/td>\n
\n
\n
Normal<\/div>\n<\/div>\n<\/td>\n
< 50 micromol\/mmol *<\/td>\n<\/tr>\n
\n
0.6 – 0.8<\/div>\n<\/td>\n
\n
Equivocal<\/div>\n<\/td>\n
<\/td>\n<\/tr>\n
\n
> 0.8<\/div>\n<\/td>\n
\n
High<\/div>\n<\/td>\n
<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

* After the age of 5 years. \u00a0Ratios are higher in infancy (Matos et al 1999<\/a>).<\/p>\n

Management principles<\/span><\/strong><\/h5>\n

Important principles are common to most stones:<\/p>\n