THE RELATION OF PROLONGED IMMOBILIZATION AND URINARY TRACT INFECTION TO RENAL CALCULUS FORMATION

Abstract

Summary 1. The literature on the subject of prolonged immobilization in relation to renal calculus formation is reviewed and six illustrative cases are reported. 2. The mechanism of calculus formation and the influence exerted thereon by urinary tract infection and prolonged immobilization are considered. 3. Insoluble crystalloids which may appear as a urinary deposit are probably prevented from crystallizing out under normal conditions rather by the fact that in a clear urinethey have very little existence as such, due to the formation of soluble complex salts, than by the “protective action” of the urinary colloids. 4. The first stage in the formation of a calculus is the deposition of crystals within the urinary passages. 5. For a calculus to develop, mechanical conditions must be such that this deposit can be retained in the urinary tract for an adequate period. 6. Under normal conditions, such stasis may occur only in the lowest renal calyx, while if urinary obstruction exists it may occur anywhere in the urinary tract. 7. A urinary infection leads to accelerated growth of calculi, but cannot alone be responsible for their formation. 8. In the presence of stasis a urea-splitting infection may by the deposition of crystals initiate calculus formation, while a non-urea-splitting infection, by providing inflammatory products on which the primary deposition of crystals may occur, may, if the urine is already dangerously close to throwing down a deposit, thus indirectly initiate calculus formation. 9. Prolonged immobilization, by interfering with the drainage from the pelvis and calyces as a result of the position occupied by the kidneys, may provide sufficient time for the deposition of crystals which would otherwise not have been deposited till the urine had been voided, and cause these crystals to be retained, thus leading to calculus formation which would otherwise never have developed.