Stueies of Emphysematous Pyelonepiritis

• Main Authors: Ming-Tao, Chen, 陳明潭
• Other Authors: Chun-Hsiung Huang
• Format: Others
• Language: zh-TW
• Published: 1997
• Online Access: http://ndltd.ncl.edu.tw/handle/20504523445830507434

博士 === 高雄醫學院 === 醫學研究所 === 85 === Emphysematous pyelonephritis(EPN) is an acute,life- threatening suppurative infection of the renal parenchyma and/or perirenal tissues. A series of thisstudy on 30 patients with EPN at our institution appreciation EPN and a new diagnosis and treatment algorithm were proposed. The contents of this study contain 2 parts and 5 topics. There are as follows: Part I. Pathogenesis of EPN: animal studies and gas analysis 1.Animal studies Two strains of Escherichia coli, E. coli O148 and E. coli O2, weredirectly injected into the renal parenchyma in streptozotocin(STZ)-diabetic rats and non-diabetic rats. E. coli 0148 strain was isolated from abscess culture of EPN and E. coli 02 strain was isolated from urinary culture of acute pyelonephritis. All of the rats injected with E. coli 02 showed similar histologic changes of acute pyelonephritis were confined to the line of inoculation. No abscesses were identified in the rats infected with E. coli 02 strain. When E. coli 0148 strain was injected, 6 of 10 rats were found to have renal abscesses. Of rats having renal abscesses, 80% were found in STZ-diabetic rats compared with 40% in non- diabetic rats. In STZ-diabetic rats, one rat was found to have gas-forming abscess in the kidney. In the remaining 4 rats infected with E.coli 0148 strain, have similar changes as acute pyelonephritis were found but the inflammatory reactions were more extensive than rats injected with E. coli 02 strain. The experimental data presented here in lend support to our belief that the virulence of bacteria is an important factor in the causation of experimental EPN and diabetes mellitus may somewhat make renal infection more susceptible. 2.Gas analysis The gas samples from 4 patients with EPN were aspirated under CT-guidance. Analyses with Varian-3700 gas chromatography/thermal conductivity detector revealed that the all gas samples had contained CO2, H2, N2. Two of the 4 patients had sulfur compound of gas analyzed by Varian 3400 GC/sulfur chemiluminence detector. These gas samples have contained H2S (1ppm and12ppm, respectively). Part II. Clinical presenation, diagnosis and treatment of EPN 1. EPN trends over the past 15 years (1982 to 1996) We retrospectively reviewed30 consecutive patients with EPN at our institution between 1982 and 1996 with particular attention to the clinical manifestations, microbiology, the utilityof radiologic studies and modes of therapy. The data were compared to those presented by Michaeli et al. who reviewed the literature of EPN between 1898 and 1982. The clinical findings in our patients were as follows: average agewas 61.8±10.2 years; the male-to-female ratio was 1:3.3; the left kidney was commonly as the right, one case was bilateral EPN; the most frequentlypredisposing factor was diabetes mellitus (93%); fever (77%) was the mostcommon presenting symptoms; abdominal or flank tender (80%) was frequently found on physical examination; typical laboratory data included leukocytosis(87%), elevated creatinine level (63%), high serum glucose concentration (93%), and pyuria (80%) etc.; the most common causative organism was E. coli (70%). There was a remarkable similarity between the clinical findings and infecting organisms in our series and in that of Michaeli et al.. Average duration of symptom before diagnosis in our series was half the time as Michaeli et al. reported (10.4 vs 21 days). Abscess cultures were positive in all our patients, but only 34% of patients had the same organisms isolated from urinary and abscess cultures. The antimicrobial susceptibility test showed that 100% of isolated Enterobacteraceae were susceptible to amikacin, and more than 80% strained sensitive to cefoperazone, norfloxacin and gentamicin.EPN was diagnosed by plain abdominal radiography (KUB) or operative findings before 1982. In comparison, KUB, ultrasound were used in diagnosisof our series. Michaeli et al. concluded that a combination of medicaland surgical treatment had the greatest chance of survival. Except of the2 cases in our series whom underwent nephrectomy before 1984, the otherswere treated initially by CT-guided PCD with a highly successful rate.As the result, we noted that the clinical findings and microbiology of EPNhave not changed during the past 15 years. However, since the availableof CT after 1982, EPN may easily be differentiated from the diagnosis of other suppurative disease of the kidney. That made the identification ofEPN patients increasing obvious and shortened the duration before accuratediagnosis in the CT era. CT-guided aspiration offered early selectionof proper antibiotics and PCD might replace the traditional surgical treatment. These have become the newest EPN treatment trends. 2.CT in the diagnosis of EPN: comparison with other imaging modalitiesy 28 patients with EPN at our institution were retrospectivelyanalyzed to determine the correlation of varied categories of the CT findingsand compared with other imaging procedures. We noted that CT demonstrated gas accumulated in the 29 kidneys of the 28 patients (bilateral lesion,1 case). In our studies, there were no correlation types of different gas- forming abscesses and the extension stages (p>0.05). However, diffuserenal damage occurred more frequently in Type I EPN than in Type II EPN(67% vs 29%,p<0.05). We recommend the use of modified lung window setting with more wide window width to clearly distinguish the gas of EPN from fatty tissue, while modified abdominal window setting with more narrowedwindow width could easily differentiate normal renal parenchyma fromfluid collection of abscess. Therefore, the modified window settings replace the enhanced study of CT and prevent side effects of contrast. Thesensitivity for detecting abnormal gas in EPN from KUB was 65.5% in our series. However, the extension of the abnormal gas in 5 of the 19 lesions was underestimated, as compared with the CT study. So the accuracy ofdiagnosing and staging EPN with KUB was about 51.9%. The sensitivity of ultrasound diagnosing EPN was 88%, while ultrasound combined with KUB increased sensitivity to 89.7% and increased specificity. Other imaging procedures offer little help in EPN diagnosis but retrograde pyelography and renal scintigraphy may be use as follow-up study to determine ureteral obstruction and evaluate the renal function after the treatment of PCD. In conclusion, we recommend simple, convenient ultrasound combined with KUB as the imaging modalities of choice for initial screening diabetic patientspresenting with evidence of upper urinary infection. If EPN is suspected or urinary infection is responding poorly to medical treatment, CT shouldbe performed to confirm the diagnosis and evaluate different types and extension of EPN. CT also offers the guidance of percutaneous drainage and follow-up procedures. 3.PCD in the treatment of EPN: results and techniques A retrospective analysis was done on 28 patients with EPN who were treatedinitially with CT guided PCD during a 11-year period. The patients were concomitantly treated with antibiotics, fluids, and correcting blood glucoseand/or ureteral obstruction. We also compared our results of PCD to CTfindings. In 22 of 28 patients (78.6%), antibiotic therapy combined with PCDconstituted the only treatment required. Three patients (10.7%) whose clinical status improved after PCD subsequently underwent elective nephrectomy without further complications. Three patients (10.7%) died ofmultiple organ failure. There was no correlation between the gas patterns of EPN and initial success with the antibiotics and PCD. There were no recurrence and no complications during a follow-up of 0.5 to 10 years (mean 5 years). Mean duration of treatment was 34.8 days (range 6 to 92 days). Based on our results , 14F Malecot catheter may adequately drain the thick purulent material thick purulent materials of EPN.