Материал: Oxford American Handbook of Urology ( PDFDrive )
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Management
The principles of management include early recognition, resuscitation, localization of the source of sepsis, early and appropriate antibiotic administration, and removal of the primary source of sepsis. From a urological perspective, the clinical scenario is a de novo presentation of patient with a clinical picture of sepsis or, as is sometimes seen, a postoperative patient who has undergone TURP or surgery for stones.
On return to the floor bed, they become febrile, develop rigors, and are tachycardic and tachypnea, resulting in initial respiratory alkalosis. They may be confused and oliguric and initially be peripherally vasodilatated (flushed appearance with warm peripheries).
It is also important to consider the possibility of a nonurological source of sepsis (such as pneumonia). If there are no indications of infection elsewhere, assume the urinary tract is the source of sepsis.
Investigations
•Urine culture. An immediate gram-stain of an unspun urine may aid in deciding which antibiotic to use.
•Full blood count. The white blood count is usually elevated. The platelet count may be low—a possible indication of impending DIC.
•Coagulation screen. This is important if surgical or radiological drainage of the source of infection is necessary.
•Creatine, blood urea nitrogen (BUN), and electrolytes as a baseline determination of renal function
•Arterial blood gases to identify hypoxia and the presence of metabolic acidosis, although respiratory alkalosis may be present initially due to tachypnea.
•Blood cultures
•Chest X-ray (CXR) to evaluate for pneumonia, atelectasis, and effusions
•Depending on the clinical situation, a renal ultrasound may be helpful to demonstrate hydronephrosis or pyonephrosis, and CT urography may be used to establish the presence or absence of other urological pathology.
Treatment
Immediate support care is necessary with attention to the basic A (Airway), B (Breathing), and C (Circulation) and to prevent cardiovascular collapse through coordinated-goal directed therapy.
•Give 100% oxygen via a facemask and monitor with use of oximetry.
•Establish IV access with a wide-bore intravenous cannula.
•Intravenous crystalloid (e.g., normal saline). Maintain adequate hemoglobin levels and transfuse if needed (>10 g/dL) to normalize blood pressure.
•Catheterize to monitor urine output.
•Obtain cultures before administering antibiotic therapy. Give empiric antibiotic therapy (see below) and adjust when cultures are available.
158 CHAPTER 5 Infections and inflammatory conditions
If there is septic shock, then the patient needs to be transferred to the intensive care unit (ICU), as ionotropic support may be needed. Steroids may have an adjunctive role in gram-negative infections and refractory septic shock. All of these steps should be coordinated with an intensivist.
Treat the underlying cause. Drain any urinary obstruction and remove any foreign body if possible. If there is a stone obstructing the ureter, insert a nephrostomy tube to relieve the obstruction or take the patient to the operating room and insert a double J-stent.
Send any urine specimens obtained for microscopy and culture.
Empirical antibiotic recommendations for treatment of urosepsis
This use of antibiotics is based on an educated guess of the most likely pathogen that has caused the urosepsis. Gram-negative aerobic rods are common causes of urosepsis (e.g., E. coli, Klebsiella, Citrobacter, Proteus, and Serratia). The enterococci (gram-positive aerobic nonhemolytic streptococci) may sometimes cause urosepsis.
In urinary tract operations involving the bowel, anaerobic bacteria may be the cause of urosepsis, and in wound infections, staphylococci (e.g.,
Staph. aureus and Staph. epidermidis) are the usual cause.2
There are no uniform published guidelines to the initial and empiric treatment of urosepsis. The following are some recommendations:
•Gentamicin is used in conjunction with other antibiotics such as ampicillin. Gentamicin has a relatively narrow therapeutic spectrum against gram-negative organisms. Close monitoring of therapeutic levels and renal function is important. It has good activity against enterobacteria and Pseudomonas, with poor activity against streptococci and anaerobes and, therefore, should ideally be combined with beta-lactam antibiotics (ampicillin) or ciprofloxacin.
•A third-generation cephalosporin (e.g., IV cefotaxime or ceftriaxone). These are active against gram-negative bacteria but have less activity against staphylococci and gram-positive bacteria. Ceftazidime also has activity against Pseudomonas aeruginosa.
•Fluoroquinolones (e.g., ciprofloxacin) are an alternative to cephalosporins. They exhibit good activity against Enterobacteriaceae and P. aeruginosa but less activity against staphylococci and enterococci.
•Monotherapy with suspected enterococci (E. faecalis) is with ampicillin 2 g IV q4h or vancomycin (if penicillin-allergic).
•Add metronidazole if there is a potential anaerobic source of sepsis.
•If Candida sepsis suspected, fluconazole 6 mg/kg/d or 400 mg IV q24h should be initiated.
If there is no clinical response to the above antibiotics, consider a combination of piperacillin and tazobactam. This combination is active against enterobacteria, enterococci, and Pseudomonas.
2 Wagenlehner FM, Weidner W, Naber KG (2007). Optimal management of urosepsis from the urological perspective. Int J Antimicrob Agents 30(5):390–397.
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If there is clinical improvement, IV treatment should continue for at least 48 hours and then be changed to oral medication. Make appropriate adjustments when sensitivity results are available from urine cultures (which may take about 48 hours).
Further reading
Bugano DD, Camargo LF, Bastos JF, Silva E (2008). Antibiotic management of sepsis: current concepts. Expert Opin Pharmacother 9(16):2817–2828.
Mackenzie I, Lever A (2007). Management of sepsis. BMJ 335(7626):929–932.
Naber KG, Bergman B, Bishop MC, et al. (2001). Guidelines on urinary and male genital tract infections. European Association of Urology, Eur Urol 40:576–588.
160 CHAPTER 5 Infections and inflammatory conditions
Fournier gangrene
Fournier gangrene is a necrotizing fasciitis of the genitalia and perineum primarily affecting males and causing necrosis and subsequent gangrene of infected tissues. Culture of infected tissue reveals a mixed polymicrobial infection with aerobic (E. coli, enterococcus, Klebsiella) and anaerobic organisms (Bacteroides, Clostridium, microaerophilic streptococci), which are believed to grow in a synergistic fashion.
Conditions predisposing to the development of Fournier gangrene include diabetes, local trauma to the genitalia and perineum (e.g., zipper injuries to the foreskin, periurethral extravasation of urine following traumatic catheterization or instrumentation of the urethra), and surgical procedures such as circumcision.
Presentation
This is one of the most dramatic and rapidly progressing infections in medicine. A previously well patient may become critically ill over a very short time course (hours). It may follow a seemingly trivial injury to the external genitalia.
A fever is usually present, the patient looks very ill, with marked pain in the affected tissues, and the developing sepsis may alter the patient’s mental state. The genitalia and perineum are edematous, and on palpation of the affected area, tenderness and crepitus may be present, indicating presence of subcutaneous gas produced by gas-forming organisms.
As the infection advances, blisters (bullae) appear in the skin and, within a matter of hours, areas of necrosis may develop on the genitalia and perineum that spread to involve adjacent tissues (e.g., the lower abdominal wall).
The condition advances rapidly—hence its alternative name of spontaneous fulminant gangrene of the genitalia.
Diagnosis
The diagnosis is a clinical one and is based on awareness of the condition and a high index of suspicion. CT will demonstrate areas of subcutaneous areas of necrosis and gas.
Treatment
Do not delay. While IV access is obtained, blood taken for culture, IV fluids started, and oxygen administered, broad-spectrum antibiotics are given to cover both gram-positive and gram-negative aerobes and anaerobes (e.g., ampicillin, gentamicin, and metronidazole or clindamycin). Monitor for signs of septic shock and manage as noted on p. 156.
Make arrangements to transfer the patient to the operating room emergently so that debridement of necrotic tissue (skin, subcutaneous fat) can be carried out. Extensive areas of tissue may have to be removed, but it is unusual for the testes or deeper penile tissues to be involved, and these can usually be spared.
A suprapubic catheter is inserted to divert urine and allow monitoring of urine output.
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Where facilities allow, consider treatment with hyperbaric oxygen therapy.1 There is some evidence that this may be beneficial. Repeated débridements to remove residual necrotic tissue are usually required with subsequent skin grafting required.
A VAC (vacuum-assisted closure) dressing can be used or wet-to- dry dressing changes are performed 2–3 times a day. Repeat operative debridement every 24–72 hours may be necessary to remove newly necrotic tissue.
Mortality is on the order of 20–30%. There is debate about whether diabetes increases the mortality rate.
Further reading
Chawla SN, Gallop C, Mydlo JH (2003). Fournier’s gangrene: an analysis of repeated surgical debridement. Eur Urol 43:572–575.
Sorensen MD, Broghammer JA, Rivara FP, et al. (2008). Fournier’s gangrene—contemporary popu- lation-based incidence and outcomes analysis: a HCUP database study. J Urol 179(4):13.
1 Mindrup SR, Kealey GP, Fallon B (2005). Hyperbaric oxygen for the treatment of Fournier’s gangrene. J Urol 173:1975–1977.