THE SOURCE OF PUS IN THE URINE.
Pus may emanate from any part of the urinary tract or may break into it at any point and be discharged along with the urine. The source is decided upon after careful examination of (A.) the urine, and (B.) the patient.
Examination of the Urine.
1. A large, thick, creamy deposit of pus in acid urine is generally due to disease of the upper urinary passages, e.g., pyelitis, chronic pyelonephritis. It separates much more quickly than does pus from the bladder, and the sample may remain acid and free from micro organisms for days. The secretion of urine is usually abundant.
2. The constant presence of viscid, glairy inuco-pus marks a vesical source. This rule is absolutely correct if taken in conjunction with bladder symptoms. Once or twice I have been deceived by patients bringing me a bottle of urine, with a large clump of phosphatic muco-pus slightly coated with blood, and with the assurance that this clump was never seen in the day but was only passed on rising. Cystoscopically one or other ureteral orifice was seen to be inflamed, swollen, and pouting; the surrounding mucous membrane was papil lated, as if fretted by irritating discharges. These cases puzzled me, for clear urine jetted out of the meters and I considered the kid neys were healthy. One patient was, however, seized with a sudden attack of severe renal pain, a symptom he had not suffered from for many years. He was admitted into another hospital and nephrolithot omy was performed, several large calculi being removed. I have since realized that these cystoscopic appearances indicate irritation of the renal pelvis, and I account for the morning appearance of a clump of muco-pus by the fact that residual urine acts in the renal pelvis during the hours of recumbency exactly like residual urine in the inflamed bladder and undergoes ammouiacal changes.
3. Intermittent Discharges of Pus in the Urine. —Wben large amounts of pus appear intermittently in the urine, it is nearly always derived from the pelvis of the kidney the ureter of which has become tempo rarily obstructed by a plug of muco-pus, or by slight twisting of the canal. It may, however, in rarer cases emanate from some extra urinary source, the channel of communication with the tract be coming periodically closed. The symptoms of fever which accom pany the non-evacuation of the pus, but which subside on its release, are additional evidences of the pent up condition ; while the pain in duced by the tension is generally a guide to the anatomical source of the discharge.
4. Threads or Flakes of Pus.—If flakes or threads of pus are passed in the urine, their source is usually urethral. In the large majority of cases this is quite reliable. The threads or pus fibres are formed by the issuing stream of urine sweeping out casts of ducts leading into the urethra, or rolling up flakes of pus and sodden epithelium which cover granular patches and post-strictural congestions. Those threads which are thin and long usually come from the anterior ure thra, while those which are broad and thick emanate from behind the compressor urethrae muscle.
It is, however, worthy of remark that pus flakes come from other parts of the tract. I have known them in inflammation of the renal
pelvis, and in renal stone, while in tuberculosis of the bladder and prostate flakes and scraps are of frequent occurrence. I have seen long flattened threads made by thick pus being forced into the blad der from a peri-vesical abscess. It is wise, therefore, before deciding that the source of the threads is urethral, to try the three-glass test.
The good old-fashioned test of making the patient urinate into two glasses is of value. Into the first are car ried the sweepings of the urethra and into the second is passed the rest of the secretion. This has been modified, and with advantage, by washing out the anterior urethra with boracic solution or with a per cent. salicylic acid solution (Keyes) .• If pus is found in the first glass or in the washings, and the second glass sample is normal, the origin of the pus is obviously in front of the compressor urethrae, and the bladder is free. At the present date this test has been still further extended by Finger, Sehlen, and others, so as to embrace morbid additions from the prostate and seminal vesicles. After the patient has cleared the urethra by urinating an ounce or two into a glass, the well-greased forefinger is passed into the rectum and the prostate is massaged lightly downward. By this means its contents' ,ire pressed into the prostatic canal and are swept into another glass by another jet of urine. Lastly the remainder of the urine is passed into a third glass. If any doubt now remains as to whether the kid ney or the bladder is furnishing the pus, the recommendation of Sir Henry Thompson is to be followed : A soft flexible catheter of medium size is passed into the bladder, the patient standing, all the urine is drawn off, and the viscus is washed out by repeated small injections of warm water. The urine is then permitted to pass along the catheter, as it will do, guttatim, into a test-tube or other small glass vessel for purposes of examination. " The bladder," says Sir Henry Thompson, "ceases for a time to be a reservoir, it does not expand but is con tracted round the catheter, and the urine percolates from the ureters direct. The ureters are virtually lengthened as far as the glass. Thus is obtained a specimen which for appreciating albumin, for de termining reaction, and for freedom from vesical pus and even blood, and from cell growths of vesical origin, is of considerable value, and has sometimes furnished me with the only data previously wanting to accomplish an exact diagnosis." 5. The Amount of Albumin Present in Pariform Urine.—The urine of pyelitis always contains albumin in excess of that due to the pus present in the secretion, the addition marking the implication of the renal structure. When one-half to one per cent. by weight of albumin exists in a filtered acid specimen of puriform urine, without blood, involvement of the pelvis of the kidney in the inflammatory process may be suspected. In decomposed urine containing pus, little can be inferred from the albumin tests (E. Fuller).