Value Of Suprapubic Bladder Aspiration In Diagnosis Of Bacteriuria

Urine obtained simultaneously by midstream voiding and supra-public bladder aspiration from 500 patients were compared by bacteriological and, in some, microscopic examination. In a second series a similar examination was undertaken on 1000 samples each, obtained by midstream voiding, catheterisation or suprapublic bladder aspiration from different patients. There was no significant difference in sediments or Stansfeld count between midstream and aspirated samples. Qualitative false-positive results for protein were obtained in 20% of midstream samples from women. The Kass count for significant bacteriuria was false-positive in 3.4% of midstream compared with bladder-aspiration samples, in 7.6% for "questionable bacteriuria". Positive counts of under 10(5)/ml were obtained in 41.3%, of under 10(4)/ml in 26.7% of aspirated samples. Counts under 10(4)/ml in midstream-voided samples are usually considered the result of contamination, at times falsely so. "Mixed infections" were 7.8 times more common in catheter and 11.4 to 11.8 times more common in midstream than in aspirated samples. The presence of microorganisms in suprapublic bladder aspiration is always abnormal. Chemotherapy is indicated only on results from bladder aspiration.