Studies in Urinary Tract Infections

Abstract

Abstract. Maximum urine concentrating ability (MCA) has been determined after the administration of vasopressin tannate in oil and found to be over 800 mOsm/kg in 26 of 28 normal subjects. Subnormal MCA was demonstrated in 93 of 157 bacteriuric women between the ages of 16 and 65. Impairment of MCA was positively correlated with clinical symptoms of acute pyelonephritis (fever and flank pain), and with a raised coli antibody litre. In 115 of the patients MCA was determined again after five to twelve months. In 34% MCA had improved by more than 25%. The assumption that this indicates acute pyelonephritis was supported by the presence of other signs of acute pyelonephritis in most of these patients in contrast to the patients who maintained a normal MCA during he observation period. It should be noted that not only Gram‐negative rods, but also coagulasenegative staphylococci, may cause acute pyelonephritis. The recurrence rate was nearly the same in patients with normal and in patients with impaired MCA before treatment, but it was significantly higher among patients in whom MCA remained low or deteriorated during the observation period than in patients whose MCA remained normal or showed improvement.