Symposium on Surgical Infections and Antibiotics
Rational Use of Prophylactic Antibiotics in Gastrointestinal Surgery
Robert E. Condon, MD.*
Condemnation of prophylactic antibiotic use is a fashionable posture among theoretically oriented physicians. It is alleged that administration of antibiotics for trivial problems is harmful to patients or, at least, ineffective. Unfortunately, valid but blanket condemnation of antibiotic prophylaxis ignores the clinical context within which drugs may be used. Against allegations that prophylactic use of antibiotics may be harmful must be set the reality that the infectious complications of gastrointestinal surgery are not trivial problems. Wound infections, abscesses, peritonitis and invasive sepsis following gastrointestinal operations are the cause of serious morbidity and represent a threat to life. The weight of evidence available in the literature indicates that prophylactic administration of appropriate antibiotics is effective in reducing the incidence of postoperative infectious complications following gastrointestinal operations. This paper reviews this evidence and records our recommendations regarding prophylactic employment of antibiotics in patients having gastrointestinal tract operations.
LITERATURE REVIEW Only reports of experience in man have been considered; the period reviewed has been confined to the last decade, necessarily excluding the report of the Ultraviolet Light Committee12 and the classic paper of Bernard and Cole. 7 However, limitation of attention to recent papers has been made so that the reports considered will record experience comparable to that of today. Further, only reports of randomized, controlled studies, utilizing at least partially effective antibiotics, have been included. These condi'Professor of Surgery, The Medical College of Wisconsin; Chief, Surgical Services, Wood Veterans Administration Center, Milwaukee
Surgical Clinics of North America- Vol. 55, No.6, December 1975
1309
tions hardly need justification since there is little or nothing to be learned from the use of ineffective antibiotics in an uncontrolled fashion. Finally, infection has been recorded only when pus has drained from the wound. This definition of a wound infection applies equally to both control and treated patients and, while it may understate slightly the incidence of wound sepsis, is hardly subject to bias. The reports dealing with systemic administration of antibiotics are summarized in Table 1. Only studies in which antibiotics were begun preoperatively have been included. If administration of antibiotics is delayed until during or after an operation, effective tissue levels of antimicrobials are absent at the time that wound contamination occurs. Under these circumstances, the incidence of wound infection is not influenced by use or non-use of antibiotics.I. 10. 11. 22. 41 The studies reviewed are a mixed bag of surgical problems and the antibiotics utilized have been effective primarily against the exogenous flora (see below). The widely quoted study of Karl and associates 24 failed to demonstrate an effect of antibiotics on wound sepsis. Similarly, the study of Stone and Hester,39 involving both systemic and topical ad-
1311
ANTIBIOTICS AND GASTROINTESTINAL SURGERY
ministration of drugs, showed no effect of antibiotics in clean trauma cases; however, the wound infection rate among their controls was sufficiently low (4 per cent) that it would be difficult to demonstrate a further reduction in wound infections in any clinical study involving reasonable numbers of patients. The remaining studies cited in Table 1 all have come to the conclusion that systemic administration of prophylactic antibiotics was effective in reducing the incidence of postoperative wound sepsis. Two important points emerge from the data in Table 1. First, use of prophylactic antibiotics has not increased the incidence or the complexity of postoperative wound infections. Second, the majority of studies show a significantly lower rate of wound infections in antibiotic treated patients. Prophylactic antibiotics also can be applied topically to the wound. Reports of the effects of this mode of therapy are recorded in Table 2. With the exception of the 1967 report of Caro and associates,t3 all Table 2. Topical Prophylactic Antibiotics (Studies in Man, 1966-1975) WOUND SEPSIS TYPE OF REFERENCE
PROCEDURE
ANTIBIOTICS
Treated No. %
Controls No. %
Caro 13
ER lac
neomycin polymyxin bacitracin
18/197
9
27/208
13
Noon 34
all
kanamycin bacitracin
24/205
12
48/199
24':'
Nash'"
colon
ampicillin t
1/36
3
14/34
41 ':'
Rickett 3 "
appendectomy
ampicillin
2/64
3
16/60
24':'
Brockenbrough 9
all
kanamycin
12/124
10
23/116
20"
Mountain 28
appendectomy
neomycin bacitracin
7/76
9
18/74
24"
Madsen"
gastric
ampicillin
0/32
0
8/32
25*
Andersen'
colon
ampicillin t
3/120
3
22/120
18"
Andersen 3
appendectomy
ampicillin
10/245
4
42/245
17':'
Stone""
trauma
neomycin (cephalosporin intravenously)
19/304
6
98/721
13*
Belzer"
renal transplant
neomycin bacitracin
1/188
0.5
8/166
5*
*Difference significant (p < 0.05). t Also received oral neomycin and sulfa or bacitracin.
1312
ROBERT
Table 3.
E.
CONDON
Oral Prophylaxis in Colon Surgery (Studies in Man, 1966-1975) WOUND SEPSIS
REFERENCE
ANTIBIOTICS
Treated No. %
Controls No. %
Everett"
neomycin
8/13
62
9/16
56
Sellwood"
neomycin bacitracin
4/19
21
10/16t
62"
Rosenberg 37
neomycin ph thalvlsu Ifa thiazo,,"
8/40
20
17/43
40'"
Barker'
colistin phthalylsulfathiazole
16/50
32
19/50t
38
Andersen'
neomycin baci tracin t
5/136
4
20/104
20*
Nichols 30
neomycin erythromycin base
0/10
0
3/10
30
Washington 42
neomycin tetracycline
3/65
5
27/63
43*
*Difference is significant (p
Rational Use of Prophylactic Antibiotics in Gastrointestinal Surgery
Robert E. Condon, MD.*
Condemnation of prophylactic antibiotic use is a fashionable posture among theoretically oriented physicians. It is alleged that administration of antibiotics for trivial problems is harmful to patients or, at least, ineffective. Unfortunately, valid but blanket condemnation of antibiotic prophylaxis ignores the clinical context within which drugs may be used. Against allegations that prophylactic use of antibiotics may be harmful must be set the reality that the infectious complications of gastrointestinal surgery are not trivial problems. Wound infections, abscesses, peritonitis and invasive sepsis following gastrointestinal operations are the cause of serious morbidity and represent a threat to life. The weight of evidence available in the literature indicates that prophylactic administration of appropriate antibiotics is effective in reducing the incidence of postoperative infectious complications following gastrointestinal operations. This paper reviews this evidence and records our recommendations regarding prophylactic employment of antibiotics in patients having gastrointestinal tract operations.
LITERATURE REVIEW Only reports of experience in man have been considered; the period reviewed has been confined to the last decade, necessarily excluding the report of the Ultraviolet Light Committee12 and the classic paper of Bernard and Cole. 7 However, limitation of attention to recent papers has been made so that the reports considered will record experience comparable to that of today. Further, only reports of randomized, controlled studies, utilizing at least partially effective antibiotics, have been included. These condi'Professor of Surgery, The Medical College of Wisconsin; Chief, Surgical Services, Wood Veterans Administration Center, Milwaukee
Surgical Clinics of North America- Vol. 55, No.6, December 1975
1309
tions hardly need justification since there is little or nothing to be learned from the use of ineffective antibiotics in an uncontrolled fashion. Finally, infection has been recorded only when pus has drained from the wound. This definition of a wound infection applies equally to both control and treated patients and, while it may understate slightly the incidence of wound sepsis, is hardly subject to bias. The reports dealing with systemic administration of antibiotics are summarized in Table 1. Only studies in which antibiotics were begun preoperatively have been included. If administration of antibiotics is delayed until during or after an operation, effective tissue levels of antimicrobials are absent at the time that wound contamination occurs. Under these circumstances, the incidence of wound infection is not influenced by use or non-use of antibiotics.I. 10. 11. 22. 41 The studies reviewed are a mixed bag of surgical problems and the antibiotics utilized have been effective primarily against the exogenous flora (see below). The widely quoted study of Karl and associates 24 failed to demonstrate an effect of antibiotics on wound sepsis. Similarly, the study of Stone and Hester,39 involving both systemic and topical ad-
1311
ANTIBIOTICS AND GASTROINTESTINAL SURGERY
ministration of drugs, showed no effect of antibiotics in clean trauma cases; however, the wound infection rate among their controls was sufficiently low (4 per cent) that it would be difficult to demonstrate a further reduction in wound infections in any clinical study involving reasonable numbers of patients. The remaining studies cited in Table 1 all have come to the conclusion that systemic administration of prophylactic antibiotics was effective in reducing the incidence of postoperative wound sepsis. Two important points emerge from the data in Table 1. First, use of prophylactic antibiotics has not increased the incidence or the complexity of postoperative wound infections. Second, the majority of studies show a significantly lower rate of wound infections in antibiotic treated patients. Prophylactic antibiotics also can be applied topically to the wound. Reports of the effects of this mode of therapy are recorded in Table 2. With the exception of the 1967 report of Caro and associates,t3 all Table 2. Topical Prophylactic Antibiotics (Studies in Man, 1966-1975) WOUND SEPSIS TYPE OF REFERENCE
PROCEDURE
ANTIBIOTICS
Treated No. %
Controls No. %
Caro 13
ER lac
neomycin polymyxin bacitracin
18/197
9
27/208
13
Noon 34
all
kanamycin bacitracin
24/205
12
48/199
24':'
Nash'"
colon
ampicillin t
1/36
3
14/34
41 ':'
Rickett 3 "
appendectomy
ampicillin
2/64
3
16/60
24':'
Brockenbrough 9
all
kanamycin
12/124
10
23/116
20"
Mountain 28
appendectomy
neomycin bacitracin
7/76
9
18/74
24"
Madsen"
gastric
ampicillin
0/32
0
8/32
25*
Andersen'
colon
ampicillin t
3/120
3
22/120
18"
Andersen 3
appendectomy
ampicillin
10/245
4
42/245
17':'
Stone""
trauma
neomycin (cephalosporin intravenously)
19/304
6
98/721
13*
Belzer"
renal transplant
neomycin bacitracin
1/188
0.5
8/166
5*
*Difference significant (p < 0.05). t Also received oral neomycin and sulfa or bacitracin.
1312
ROBERT
Table 3.
E.
CONDON
Oral Prophylaxis in Colon Surgery (Studies in Man, 1966-1975) WOUND SEPSIS
REFERENCE
ANTIBIOTICS
Treated No. %
Controls No. %
Everett"
neomycin
8/13
62
9/16
56
Sellwood"
neomycin bacitracin
4/19
21
10/16t
62"
Rosenberg 37
neomycin ph thalvlsu Ifa thiazo,,"
8/40
20
17/43
40'"
Barker'
colistin phthalylsulfathiazole
16/50
32
19/50t
38
Andersen'
neomycin baci tracin t
5/136
4
20/104
20*
Nichols 30
neomycin erythromycin base
0/10
0
3/10
30
Washington 42
neomycin tetracycline
3/65
5
27/63
43*
*Difference is significant (p
