Session VII F. Calais da Silva
Prophylactic Antibiotherapy in Urological Surgery* S u m m a r y : The aim of prophylactic antibiotic therapy in
urological surgery is the prevention of local or systemic infections. The authors treated 100 patients prophylactically; 62 were treated with amikacin and 38 with cefotaxime. Of the 62 patients treated with amikacin, 18 had infectious complications. Of the 38 patients treated with cefotaxime, ten had infectious complications. We conclude that in the Hospital do Desterro the incidence of infectious complications is high, despite antibiotic prophylaxis. Z u s a m m e n f a s s u n g : Antibiotikaprophylaxe bei urologischen Operationen. Das Ziel der Antibiotikaprophylaxe
bei urologischen Operationen ist die Verhinderung von lokalen und systemischen Infektionen. Die Autoren ftihrten bei 100 Patienten eine Prophylaxe durch; 62 Patienten wurden mit Amikacin und 38 Patienten mit Cefotaxim behandelt. Von den 62 mit Amikacin behandelten Patienten hatten 18 und von den 38 mit Cefotaxim behandelten Patienten hatten zehn Patienten infekti6se Komplikationen. Daraus ergibt sich, dab trotz Antibiotikaprophylaxe das Auftreten infekti6ser Komplikationen im Hospital do Desterro hoch ist.
Introduction
Prophylactic antibiotic therapy in urological surgery is a controversial subject. Several studies have been published, but it is difficult to draw any conclusions, as they are uncontrolled studies. They vary as to the antimicrobial agents used, type of surgery and duration of catheterization; therefore a comparison is not possible. The aim of prophylactic antibiotic therapy in urological surgery is the prevention of local infections (urine, wound) or systemic infections (septicaemia, fever, chills) in patients who have sterile urine, excluding patients presenting with bacteriuria, or local or general symptoms of infection before surgery. In these patients the risk of developing bacteraemia without therapy is 50 to 60%. The definition of preoperative sterile urine is important and means the absence of microorganisms - and not < 105 or 104 cfu/ml 48 h before the operation. Six to 12% of patients who are apparently "sterile" are actually infected, as compared to those who were catheterized or those with a previous history of urinary infection. If prophylactic antibiotic therapy is not used in urological surgery where catheters are used (prostatectomy, bladder surgery and TUR), we may expect post-operative bacteriuria in 11 - 5 7 % of the patients (average 25 -30%), depending on such individual factors as hygienic
conditions and type of surgery. Bacteriuria shall be considered a reference point of urinary morbidity, for example in prostatitis and epididymitis. When using prophylactic antibiotic therapy with that type of surgery, the rate of postoperative bacteriuria decreases in many studies to 0-35% (average 5 - 10%), although the factors referred to above are very important in the evaluation of these numbers. Genitourinary surgical prophylaxis would serve to: - prevent perioperative bacteraemia - about 10% of the patients are actually infected, of whom approximately 50% have bacteraemia; - prevent or to reduce the occurrence of postoperative bacteriuria from 20-25% to 5-10%. The first category applies to patients for whom the risk of bacteraemia is greater or its consequences more serious, including patients with previous catheterization or a previous history of urinary tract infection, those with valvular heart disease, patients with prosthetic devices, diabetics and immunosuppressed persons. In the second category, environmental factors - hygiene in the operating theatre, medical and nursing staff, the patients themselves, the microbial hospital population - as well as, for example, the type of operation and duration of catheterization are of great importance in the determination of values determined by the different authors. On the other hand, the general use of prophylactic antibiotics in surgery may be criticized, because drugs have side-effects and adverse reactions, are often expensive and can change either the individual or environmental flora with the corresponding development of resistance. Thus, the question is no longer whether prophylactic antibiotics are effective, but rather for whom they can be of value and under what conditions. Operations may be divided into five groups: 1) Surgery withgut the use of catheters and without contact with urine (nephrectomy, genital surgery), where the risk of infection is < 5% and does not justify prophylaxis according to the majority of authors. 2) Surgery without the use of catheters, with contact with urine (lithotomy, pyeloplasty) where the risk of infection is approximately 10% and where many authors advise prophylaxis in high-risk patients (diabetics, immunosuppressed, malnourished patients or those with prosthetic devices, etc.). F. Calais da Silva, M. D., Dept. of Urology, Hospital do Desterro, Praceta Bento Moura Portugal, 2-1 Esqu., Venda Nova, P-2700 Amadora, Portugal. * Dr. Calais da Silva's discussion could not be presented during the meeting because of an unforeseen event, but he kindly provided us with this discussion.
Infection 20 (1992) Suppl. 3 © MMV Medizin Veflag GmbH M0nchen, Mtinchen 1992
S 221
F. C a l a i s d a Silva: Prophylactic Antibiotics in Urological Surgery
3) Surgery with the use of catheters, with contact with urine (prostatectomy, bladder surgery) with a 25-30% risk of infection. 4) Surgery with the use of catheters, without breaking the skin (TUR), with the risk of infection approximately 25-30%, according to many authors an indication for prophylaxis. Some authors, however, do not advise the use of antibiotic prophylaxis for this group, but either the standards of hospital hygiene are very high or their recommendations may be questionable. 5) "Dirty" (contaminated) surgery (preoperative bacteriuria, local or general signs of infection, intestinal surgery without proper preparation, surgery following trauma), where the risk of infection is > 50% and does not justify prophylaxis but preoperative therapy followed by a postoperative treatment regimen. When selecting prophylactic antibiotic therapy, the antibiotic chosen must be safe, with no toxicity and an appropriate bacterial spectrum. An appropriate dose should be administered so that during surgery, serum, tissue and urinary levels are maintained. Short-course administration is preferable, especially to avoid a change in the bacterial flora and to prevent the development of resistance. Also it is more cost-effective and easier for the patient. Several types of drugs have been used and in the literature various regimens of different antibiotics have been described. Third generation cephalosporins (cefotaxime, ceftriaxone), fourth generation penicillins (piperacillin, mezlocillin), monobactams (aztreonam) and aminoglycosides (amikacin, tobramycin, netilmicin) have been recommended. In order to assess the value of prophylactic antibiotic therapy in our department, we evaluated two drugs amikacin and cefotaxime.
formation, etc.) and urine cultures were carried out on the third postoperative day, when catheters were removed and during the ~econd and fourth postoperative weeks.
Materials and Methods
Table 3: Cefotaxime, surgery without the use of catheters.
In this protocol, 500 mg of amikacin or 1 g of cefotaxime were injected i.m. 2 h before surgery and repeated 12 h after the first administration, and again when catheters were used 2 h before their removal. Only patients with local or general signs of infection and with negative urine cultures prior to surgical intervention were admitted. For classification purposes, according to the surgical intervention performed, we considered two groups: 1. a) Surgery without the use o f catheters, not invading the urinary tract; b) Surgery without the use of catheters, but invading the urinary tract; 2. c) Surgery with the use of catheters, breaking the skin and urinary tract; d) Surgery with the use of catheters, not breaking the skin but opening the urinary tract. The mean duration of catheterization was six days for group 2 c (maximum 9, minimum 4) and four days for group 2 d (maximum 7, minimum 2). Daily clinical evaluation was performed postoperatively to determine morbidity (fever > 38°C for more than 24 h, wound infection, deep abscess, epididymitis, fistula
S 222
Results
Of 100 patients, 62 were treated with amikacin and 38 with cefotaxime. Of the 62 patients treated with amikacin, 18 belonged to group 1 and 44 to group 2. Of the 38 patients treated with cefotaxime, 11 belonged to group 1 and 27 to group 2.
Table 1 : Amikacin, surgery without the use of catheters.
Without complications Bacteriuria Fever Wound infection Epididymitis
4 0 0 0
9 5* 1 2 -
13 5* 1 2 -
"1 case of superinfection. Table 2: Amikacin, surgery with the use of catheters.
Without complications Bacteriuria Fever Wound infection Epididymitis
10 4 1 1 1
21 9 1 4
3i 13" 2 1 5
*1 case of superinfection.
Without complications Bacteriuria Fever Wound infection Epididymitis
3 0 0 0
6 2 0 0 -
9 2 0 0 0
Table 4: Cefotaxime, surgery with the use of catheters.
Without complications Bacteriuria Fever Wound infection Epididymitis
6 3 1 0 0
13 5 1 0
19 8 2 0 0
Infection 20 (1992) Suppl. 3 © MMV Medizin Verlag GmbH Miinchen, Mfinchen 1992
F. Calais da Silva: Prophylactic Antibiotics in Urological Surgery There was no toxic reaction in the amikacin group, 18 (29%) had complications (Tables 1, 2); of the 38 patients in the cefotaxime group ten (26%) had complications (Tables 3, 4). When bacteriuria was detected, it was treated according to the antibiogram and we do not know how many cases of early bacteriuria resolved spontaneously. Only one patient of the total 100 participants, in the amikacin group, suffered late bacteriuria. In two patients in the amikacin group superinfection occurred (Escherichia coli over KlebsieUa and Pseudomonas over Klebsietla). In conclusion, these results show that in the Hospital do Desterro the number of infectious complications is high, in spite of antibiotic prophylaxis. There were no significant differences between amikacin and cefotaxime, therefore we conclude that in our hospital the efficacy of both drugs is similar in urological antibiotic prophylaxis. Discussion
Antibiotic prophylaxis as described in the literature is highly variable, not only in the products used, but also in the length of therapy. Most authors are in favour of prophylactic antibiotics in the preoperative period and of continuing for various periods postoperatively (from 12 h to three weeks) [1]. It is noteworthly, however, that certain studies have favoured a prophylactic antibiotic beginning immediately postoperatively, and the results obtained were similar. Thus, the prophylactic prescription of antibiotics must be the consequence of a decision-making process which takes into account the types of patients being treated, the type of surgery proposed, the hygienic conditions under which the patients will be nursed, the method of administration
of the drug, and the eventual morbidity associated with the antibiotics themselves. In a thorough review and critique of the English-language literature, Chodak and Plaut [2] attempted-to define general rules for the use of prophylactic antibiotics in prostatic surgery, endoscopy, and indwelling catheterization. However, they were unable to set down any general rules because some authors reported beneficial effects from prophylactic antibiotics, while others failed to give evidence of any positive effect. We feel that each speciality, after considering the types of patients being treated and, more important, prevailing hygienic conditions, must determine individually whether or not antibiotic prophylaxis should be used. The incidence of bacteriuria in a control group appears to be a good reflection of the need. In the case of patients having prostatic surgery, for example, the incidence of bacteriuria of more than 20% in a control group must be considered as an indication for prescribing prophylactic antibiotic therapy of the type which is able to limit bacteriuria to less than 5% of the patients in the treated group. Similar reasoning should be employed for each type of intervention when the risk factors have been determined.
References 1. Morris, M. J., Golosvky, D., Guniess, M. D., Mahler, P. O.: The value of prophylactic antibiotics in transurethral prostatic resection. A controlled trial with observations on the origin of postoperative infection. Br. J. Urol. 48 (1976) 479--484. 2. Chodak, G., Plaut, M. E.: Systemic antibiotics for prophylaxis in urology surgery. A critical review. J. Urol. 121 (1979) 695-699.
Infection 20 (1992) Suppl. 3 © MMV Medizin Verlag GmbH Miinchen, Miinchen 1992
S 223
Prophylactic Antibiotherapy in Urological Surgery* S u m m a r y : The aim of prophylactic antibiotic therapy in
urological surgery is the prevention of local or systemic infections. The authors treated 100 patients prophylactically; 62 were treated with amikacin and 38 with cefotaxime. Of the 62 patients treated with amikacin, 18 had infectious complications. Of the 38 patients treated with cefotaxime, ten had infectious complications. We conclude that in the Hospital do Desterro the incidence of infectious complications is high, despite antibiotic prophylaxis. Z u s a m m e n f a s s u n g : Antibiotikaprophylaxe bei urologischen Operationen. Das Ziel der Antibiotikaprophylaxe
bei urologischen Operationen ist die Verhinderung von lokalen und systemischen Infektionen. Die Autoren ftihrten bei 100 Patienten eine Prophylaxe durch; 62 Patienten wurden mit Amikacin und 38 Patienten mit Cefotaxim behandelt. Von den 62 mit Amikacin behandelten Patienten hatten 18 und von den 38 mit Cefotaxim behandelten Patienten hatten zehn Patienten infekti6se Komplikationen. Daraus ergibt sich, dab trotz Antibiotikaprophylaxe das Auftreten infekti6ser Komplikationen im Hospital do Desterro hoch ist.
Introduction
Prophylactic antibiotic therapy in urological surgery is a controversial subject. Several studies have been published, but it is difficult to draw any conclusions, as they are uncontrolled studies. They vary as to the antimicrobial agents used, type of surgery and duration of catheterization; therefore a comparison is not possible. The aim of prophylactic antibiotic therapy in urological surgery is the prevention of local infections (urine, wound) or systemic infections (septicaemia, fever, chills) in patients who have sterile urine, excluding patients presenting with bacteriuria, or local or general symptoms of infection before surgery. In these patients the risk of developing bacteraemia without therapy is 50 to 60%. The definition of preoperative sterile urine is important and means the absence of microorganisms - and not < 105 or 104 cfu/ml 48 h before the operation. Six to 12% of patients who are apparently "sterile" are actually infected, as compared to those who were catheterized or those with a previous history of urinary infection. If prophylactic antibiotic therapy is not used in urological surgery where catheters are used (prostatectomy, bladder surgery and TUR), we may expect post-operative bacteriuria in 11 - 5 7 % of the patients (average 25 -30%), depending on such individual factors as hygienic
conditions and type of surgery. Bacteriuria shall be considered a reference point of urinary morbidity, for example in prostatitis and epididymitis. When using prophylactic antibiotic therapy with that type of surgery, the rate of postoperative bacteriuria decreases in many studies to 0-35% (average 5 - 10%), although the factors referred to above are very important in the evaluation of these numbers. Genitourinary surgical prophylaxis would serve to: - prevent perioperative bacteraemia - about 10% of the patients are actually infected, of whom approximately 50% have bacteraemia; - prevent or to reduce the occurrence of postoperative bacteriuria from 20-25% to 5-10%. The first category applies to patients for whom the risk of bacteraemia is greater or its consequences more serious, including patients with previous catheterization or a previous history of urinary tract infection, those with valvular heart disease, patients with prosthetic devices, diabetics and immunosuppressed persons. In the second category, environmental factors - hygiene in the operating theatre, medical and nursing staff, the patients themselves, the microbial hospital population - as well as, for example, the type of operation and duration of catheterization are of great importance in the determination of values determined by the different authors. On the other hand, the general use of prophylactic antibiotics in surgery may be criticized, because drugs have side-effects and adverse reactions, are often expensive and can change either the individual or environmental flora with the corresponding development of resistance. Thus, the question is no longer whether prophylactic antibiotics are effective, but rather for whom they can be of value and under what conditions. Operations may be divided into five groups: 1) Surgery withgut the use of catheters and without contact with urine (nephrectomy, genital surgery), where the risk of infection is < 5% and does not justify prophylaxis according to the majority of authors. 2) Surgery without the use of catheters, with contact with urine (lithotomy, pyeloplasty) where the risk of infection is approximately 10% and where many authors advise prophylaxis in high-risk patients (diabetics, immunosuppressed, malnourished patients or those with prosthetic devices, etc.). F. Calais da Silva, M. D., Dept. of Urology, Hospital do Desterro, Praceta Bento Moura Portugal, 2-1 Esqu., Venda Nova, P-2700 Amadora, Portugal. * Dr. Calais da Silva's discussion could not be presented during the meeting because of an unforeseen event, but he kindly provided us with this discussion.
Infection 20 (1992) Suppl. 3 © MMV Medizin Veflag GmbH M0nchen, Mtinchen 1992
S 221
F. C a l a i s d a Silva: Prophylactic Antibiotics in Urological Surgery
3) Surgery with the use of catheters, with contact with urine (prostatectomy, bladder surgery) with a 25-30% risk of infection. 4) Surgery with the use of catheters, without breaking the skin (TUR), with the risk of infection approximately 25-30%, according to many authors an indication for prophylaxis. Some authors, however, do not advise the use of antibiotic prophylaxis for this group, but either the standards of hospital hygiene are very high or their recommendations may be questionable. 5) "Dirty" (contaminated) surgery (preoperative bacteriuria, local or general signs of infection, intestinal surgery without proper preparation, surgery following trauma), where the risk of infection is > 50% and does not justify prophylaxis but preoperative therapy followed by a postoperative treatment regimen. When selecting prophylactic antibiotic therapy, the antibiotic chosen must be safe, with no toxicity and an appropriate bacterial spectrum. An appropriate dose should be administered so that during surgery, serum, tissue and urinary levels are maintained. Short-course administration is preferable, especially to avoid a change in the bacterial flora and to prevent the development of resistance. Also it is more cost-effective and easier for the patient. Several types of drugs have been used and in the literature various regimens of different antibiotics have been described. Third generation cephalosporins (cefotaxime, ceftriaxone), fourth generation penicillins (piperacillin, mezlocillin), monobactams (aztreonam) and aminoglycosides (amikacin, tobramycin, netilmicin) have been recommended. In order to assess the value of prophylactic antibiotic therapy in our department, we evaluated two drugs amikacin and cefotaxime.
formation, etc.) and urine cultures were carried out on the third postoperative day, when catheters were removed and during the ~econd and fourth postoperative weeks.
Materials and Methods
Table 3: Cefotaxime, surgery without the use of catheters.
In this protocol, 500 mg of amikacin or 1 g of cefotaxime were injected i.m. 2 h before surgery and repeated 12 h after the first administration, and again when catheters were used 2 h before their removal. Only patients with local or general signs of infection and with negative urine cultures prior to surgical intervention were admitted. For classification purposes, according to the surgical intervention performed, we considered two groups: 1. a) Surgery without the use o f catheters, not invading the urinary tract; b) Surgery without the use of catheters, but invading the urinary tract; 2. c) Surgery with the use of catheters, breaking the skin and urinary tract; d) Surgery with the use of catheters, not breaking the skin but opening the urinary tract. The mean duration of catheterization was six days for group 2 c (maximum 9, minimum 4) and four days for group 2 d (maximum 7, minimum 2). Daily clinical evaluation was performed postoperatively to determine morbidity (fever > 38°C for more than 24 h, wound infection, deep abscess, epididymitis, fistula
S 222
Results
Of 100 patients, 62 were treated with amikacin and 38 with cefotaxime. Of the 62 patients treated with amikacin, 18 belonged to group 1 and 44 to group 2. Of the 38 patients treated with cefotaxime, 11 belonged to group 1 and 27 to group 2.
Table 1 : Amikacin, surgery without the use of catheters.
Without complications Bacteriuria Fever Wound infection Epididymitis
4 0 0 0
9 5* 1 2 -
13 5* 1 2 -
"1 case of superinfection. Table 2: Amikacin, surgery with the use of catheters.
Without complications Bacteriuria Fever Wound infection Epididymitis
10 4 1 1 1
21 9 1 4
3i 13" 2 1 5
*1 case of superinfection.
Without complications Bacteriuria Fever Wound infection Epididymitis
3 0 0 0
6 2 0 0 -
9 2 0 0 0
Table 4: Cefotaxime, surgery with the use of catheters.
Without complications Bacteriuria Fever Wound infection Epididymitis
6 3 1 0 0
13 5 1 0
19 8 2 0 0
Infection 20 (1992) Suppl. 3 © MMV Medizin Verlag GmbH Miinchen, Mfinchen 1992
F. Calais da Silva: Prophylactic Antibiotics in Urological Surgery There was no toxic reaction in the amikacin group, 18 (29%) had complications (Tables 1, 2); of the 38 patients in the cefotaxime group ten (26%) had complications (Tables 3, 4). When bacteriuria was detected, it was treated according to the antibiogram and we do not know how many cases of early bacteriuria resolved spontaneously. Only one patient of the total 100 participants, in the amikacin group, suffered late bacteriuria. In two patients in the amikacin group superinfection occurred (Escherichia coli over KlebsieUa and Pseudomonas over Klebsietla). In conclusion, these results show that in the Hospital do Desterro the number of infectious complications is high, in spite of antibiotic prophylaxis. There were no significant differences between amikacin and cefotaxime, therefore we conclude that in our hospital the efficacy of both drugs is similar in urological antibiotic prophylaxis. Discussion
Antibiotic prophylaxis as described in the literature is highly variable, not only in the products used, but also in the length of therapy. Most authors are in favour of prophylactic antibiotics in the preoperative period and of continuing for various periods postoperatively (from 12 h to three weeks) [1]. It is noteworthly, however, that certain studies have favoured a prophylactic antibiotic beginning immediately postoperatively, and the results obtained were similar. Thus, the prophylactic prescription of antibiotics must be the consequence of a decision-making process which takes into account the types of patients being treated, the type of surgery proposed, the hygienic conditions under which the patients will be nursed, the method of administration
of the drug, and the eventual morbidity associated with the antibiotics themselves. In a thorough review and critique of the English-language literature, Chodak and Plaut [2] attempted-to define general rules for the use of prophylactic antibiotics in prostatic surgery, endoscopy, and indwelling catheterization. However, they were unable to set down any general rules because some authors reported beneficial effects from prophylactic antibiotics, while others failed to give evidence of any positive effect. We feel that each speciality, after considering the types of patients being treated and, more important, prevailing hygienic conditions, must determine individually whether or not antibiotic prophylaxis should be used. The incidence of bacteriuria in a control group appears to be a good reflection of the need. In the case of patients having prostatic surgery, for example, the incidence of bacteriuria of more than 20% in a control group must be considered as an indication for prescribing prophylactic antibiotic therapy of the type which is able to limit bacteriuria to less than 5% of the patients in the treated group. Similar reasoning should be employed for each type of intervention when the risk factors have been determined.
References 1. Morris, M. J., Golosvky, D., Guniess, M. D., Mahler, P. O.: The value of prophylactic antibiotics in transurethral prostatic resection. A controlled trial with observations on the origin of postoperative infection. Br. J. Urol. 48 (1976) 479--484. 2. Chodak, G., Plaut, M. E.: Systemic antibiotics for prophylaxis in urology surgery. A critical review. J. Urol. 121 (1979) 695-699.
Infection 20 (1992) Suppl. 3 © MMV Medizin Verlag GmbH Miinchen, Miinchen 1992
S 223
