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Postoperative wound infection at a university hospital in Jeddah, Saudi Arabia
Journal
of Hospital
Infection
(1992) 21, 79-83
SHORT
Postoperative hospital A. T. A. Eltahawy”,
REPORT
wound infection at a university in Jeddah, Saudi Arabia A. ‘4. Mokhtarj-, Ragaa ,4. A. Bahnassy$
M. F. KhalaP
and
“Department of Microbiology, King Abdulaziz University Hospital. P.O. Box 6615, Jeddah-21452, TDepartment of Swgery, College of Medicine, k-ing Abdulaziz University, P.O. Box 9029, Jeddah-21413. JDepartment of Community Medicine and Primary Health Care, College of Medicine, King Abdulaziz University, P.O. Box 9029, yeddah-21413, Saudi Arabia. Accepted for publication
7 February
1992
Summary: A prospective study was made of 1418 surgical wounds at the 250-bed King Abdulaziz University Hospital in Jeddah, Saudi Arabia. Daily examinations of wounds, cultures of all suspicious wounds and 28 days outpatient clinic follow-up were performed. The overall infection rate was 9%. The infection rate after clean surgery was 9.5%. High rates of infections were noted after colon resection (19%), caesarean section (19%), abdominal hysterectomy (10%) and cholecystectomy (10%). The infection rates after appendectomy, mastectomy and herniorrhaphy were approximately 7%. A lower rate of infection was seen after thyroidectomy (2%). The incidence of infection was significantly related to pre-operative stay in hospital and to duration of operation.
Introduction
In spite of modern standards of preoperative preparation, antibiotic prophylaxis and advances in anaesthetic and operative techniques, postoperative wound infections still remain a major problem associated with significant morbidity and mortality. * Many factors affect the incidence of surgical wound infection, in addition to the surgeon’s skill and the hospital environment. Host attributes, such as age over 60 years, diabetes mellitus, malignant disease, obesity, malnutrition, length of preoperative stay or pre-existing infection may influence risk, as may such operation characteristics as site, urgency, duration and time of skin shaving.24 Surgical wound infection is the second most frequently encountered hospital-acquired infection at King Abdulaziz University Hospital (KAUH). This study reports a 2-year prospective postoperative wound Correspondence 0195-6701/92/050079+05
to: Dr A. T. A. Eltahawy. $03.00/O
0 I997 The Hoapd
79
Infection
Smery
80
A. T. A. Eltahawy
et al.
surveillance programme initiated in August 1987 at KAUH, which has 250 beds (92 surgical or gynaecological) and three operating theatres. The aim was to determine the rate of infection and the factors that influence the infection rate, to obtain statistical background for future investigation of variables and to improve our infection rate and bed utilization. Methods
All operations that were performed at KAUH between August 1987 and July 1989 were included except oral, rectal and vaginal operations, transurethral resection of the prostate, burn treatments and circumcisions. Wounds were observed by an infection control nurse daily during the patients’ stay in hospital. After discharge, wounds were inspected at each follow-up outpatient attendance and for at least 28 days postoperatively. Microscopy and aerobic and anaerobic cultures were performed on a specimen from any wound that appeared inflamed and demonstrated drainage of any type within 4 weeks of operation. The definition of wound infection proposed by the Centers for Disease Control was used. This requires purulent drainage or a positive culture or a deliberately opened wound or a surgeon’s diagnosis.5 Operations were classified into clean, clean-contaminated, contaminated and dirty as defined by the National Research Council.2 Information recorded on worksheets included the patient’s characteristics, such as age, sex, weight and underlying diseases, and patient-care variables such as preoperative hospitalization, hair removal, type of surgery, length of operation, presence of drains and type of drainage. The x2 test was used to test association between the infection rate and the length of the operation, the length of preoperative stay, insertion of drains and types of drainage. The t-test was used to compare the mean days of stay following the operation for both infected and non-infected wounds. Results
Over the 2-year study period, there were 127 wound infections in 1418 wounds, an overall infection rate of 9% (Table I). Infection rates for certain commonly performed surgical procedures are listed in Table II. Herniorrhaphy was the most common operation at KAUH, accounting for 21% of the operations performed. Cholecystectomy, caesarean section and of the appendectomy accounted for 16%) 15% and 5.5% respectively, operations carried out. High rates of infection were noted in the following operations: colon resection (18.7), caesarean section (18.7), abdominal hysterectomy (10.4%) and cholecystectomy (10.1). The infection rates after appendectomy, mastectomy and herniorrhaphy were 6.6%) 6.9% and 7.4% respectively. A low rate of infection was seen after thyroidectomy (1.9%). The frequency of recovery of the four most common organisms causing wound infection in the study were Staphylococcus aUreUS (41%), dominant
Postoperative Table
wound
I. Incidence
Classification of operative procedure5
78
Clean-contaminated Contaminated
81
of wound infection
Infected No. %
Clean
infection
Not infected No. %
Total
9.5
742
90.5
820
34
6.3
510
93.7
544
10
21.3
37
78.7
47
Dirty
5
71.4
2
28.6
7
Total
127
9.0
1291
91.0
1418
Table Type
II.
of operation
Appendectomy Cholecystectomy Caesarean section Abdominal hysterectomy Colon resection Herniorrhaphy Mastectomy Orthopaedic operations Splenectomy Thoracotomy Thyroidectomy Stomach and oesophagus operations Urological operations Others Total
Infection
rates for common surgical Infected No. % 5 22 39 5 6 21 4 8
procedures
Not infected No. %
Total
ii
6.6 10.1 18.7 10.4 19.4 7.4 6.9 4.6 0 0
71 196 170 43 25 262 54 165 14 4
93.4 89.9 81.3 89.6 80.6 92.6 93.1 95.4 100 100
76 218 209 48 31 283 58 173 14 4
01
01.9
53 54
98.1 100
:t
9 7 127
7.1 10.0 9.0
117 63 1291
92.9 90.0 91.0
126 70 1418
on sites other than the gastro-intestinal tract, Klebsiella and spp. (1 S%), Escherichia coli (12%) and Pseudomonas species (9%). A significant relationship between operations with a duration of more than 2 h and an increase in the postoperative wound infection rate was observed in patients undergoing cholecystectomy, mastectomy and appendectomy; the infection rates for operations of more than 2 h vs. less than 2 h were: cholecystectomy-54.6%, (12/22) vs. 25%, (49/196) [x2 = 8.57, P-C 0.011 mastectomy-SO% (2/4) vs. 5.6% (3/54) [corrected x2=455, P
operations
Enterobacter
82
A. T. A. Eltahawy
et al.
with 13% of patients without any infection (163/1291) [x2=6.16, P
The rates of infection in this study after ‘clean-contaminated’, and ‘contaminated’ procedures (6.3% and 21 “A) fall between the extremes reported by others. 6-l’ Infections were detected more frequently in wounds after ‘clean’ than after ‘clean-contaminated’ surgery (9.5% vs. 6.3%). Standard plenum ventilation is supplied to the operating theatres and instrument sterilization is regularly monitored. The deportment of the shows some deficiencies, such as improper surgical team, however, excessive traffic in the operating theatre, rough handling of masking, tissues, excessive talking by the surgical team and an excessive number of people in the theatre. Preoperative non-electric razor shaving, too, such as was used on all our patients, has been shown to be associated with a higher infection rate than depilatory treatment.” The duration of preoperative hospitalization has previously been shown to be a risk factor for postoperative wound infections,‘a9 as has a duration of relationship between the operation of more than 2 h. 12-14The significant type of drainage and infection rate in our study and the lack of significant association between insertion of any type of drain and infection are rates after appendectomy consistent with other reports. 3,8,15The infection and cholecystectomy are similar to those reported by others.‘a’6-19 The infection rate after cholecystectomy without exploration of common bile duct was 6% (11/180), significantly lower than the 29% rate (11/38) for cholecystectomy with exploration of the duct (PC 0.001). The infection rate after caesarean section compared favourably with that reported by Farber and Wenzel;17 on the other hand, their reported rate of infection after colon resection was considerably lower than our rate (12% vs. 19%). Approximately 40% (12/31) of patients with wound infections after ‘contaminated’ procedures and 57% (199/348) of those with wound infections after ‘clean-contaminated’ procedures in this study were given no antibiotic prophylaxis is indicated for such preoperative antibiotics; operations 20,21 Omission of preoperative antibiotics was noted in 60% (13 1j218) of patients who had cholecystectomy whose wounds later became infected (7%).
Postoperative
wound
infection
83
The results of this study serve as a base line for future comparison and emphasize the important economic as well as human consequences of surgical wound infection. They indicate some actions which need to be taken to improve the rates of infection after different types of surgery. We thank study.
Mrs
Layla
Tabash,
Infection
Control
Nurse,
for her excellent
assistance
in this
References M, Schwartz ML. Surgical wound infections. A S-year prospective 1. Olson M, O’Connor study of 20,193 wounds at the Minneapolis VA Medical Center. Ann Surg 1984; 199: 253-259. Academy of Sciences-National Research Council. Ad Hoc Committee of the 2. National Committee on trauma, Division of Medical Sciences. Postoperative Wound Infections: The influence of ultraviolet irradiation of the operating room and of various other factors. Ann Surg 1964; 160 (Suppl 2): 1-192. AIG. Clark C. Smith G. Postonerative wound infection: a commuter analvsis. 3. Davidson BrJ Surg 1971; 58: 333-336. 4. Edwards LD. The epidemiology of 2056 remote site infections and 1966 surgical wound infections occurring in 1865 patients. Ann Surp 1976; 184: 7588766. JS, Jarvis WR, Emori TG, Horan TC, Hughes JM. CDC definitions for 5. Garner nosocomial infections. Am r 1afect Control 1988; 16: 128-140. etiology, prevention and management. Surg Clin North Am 6. Todd JC. Wound infection: 1968; 48: 787-798. Service. The incidence of wound infections in England and 7. Public Health Laboratory Wales. Lancet 1960; 2: 659. study of 23,649 surgical wounds. Arch Surg 8. Cruse PJE, Foord R. A five-year prospective 1973; 107: 206-209. in hospitals: wound infections. r Hasp Infect 9. Report on the national survey of infection 1980; 2 (Suppl): 29934. patients at high risk of surgical 10. Haley RW, Culver DH, Morgan WM, et al. Identifying wound infection: a sample multi-variate index of patient susceptibility and wound contamination. AmJ Epidemiol. 1985; 121: 206-215. 11. Seropian R, Reynolds BM. Wound infections after preoperative depilatory versus razor preparation. AmJ Surg 1971; 121: 251-254. of wound infection: a lo-year prospective study 12. Cruse PJE, Foord R. The epidemiology of 62,939 wounds. Surg Clin N#orth Am 1980; 60: 27-40. wound infection. Predisposing factors and the effect of a 13. Brunn JN. Postoperative reduction in the dissemination of staphylococci. Acta Med Stand 1970; 514: (Suppl) l-89. sepsis. Mt Sinai J Med hTY 1970; 37: 14. Koota GM. A study of major postoperative 590-602. E, Stein H, Sacks TG, Shapiro M. Mitchel J. Multivariate analysis of 15. Simchen determinants of postoperative wound infection in orthopaedic patients. J Hosp Infect 1984; 5: 137-146. WA, Culbertson WR, Hummel RP. Surgical considerations of endogenous 16. Altemeier infection. Sources, types and methods of control. Surg Clin North Am 1968; 46: 2277240. RP. Postoperative wound infection rates: results of prospective 17 Farber BF, Wenzel, statewide surveillance. Am r Surg 1980; 140: 3433346. and bile culture in 800 consecutive 18 Reiss R, Eliashiv A, Deutsch A. Septic complication cholecystectomies. World J Surg 1982; 6: 195-199. J, Aho J. Wound infection in abdominal surgery. Act Chir Stand 19. Renvall S, Niinikoshi 1980; 146: 25-30. prophylaxis in surgical patients. Bull NY Acad 20. Gilbert DN. Current status of antibiotic Med 1984; 60: 340-357. 21. Kaufman Z, Englberg M, Eliashiv A, Reiss R. Systemic prophylactic antibiotic in elective billiary surgery Arch Surg 1984; 119: 100221004.
of Hospital
Infection
(1992) 21, 79-83
SHORT
Postoperative hospital A. T. A. Eltahawy”,
REPORT
wound infection at a university in Jeddah, Saudi Arabia A. ‘4. Mokhtarj-, Ragaa ,4. A. Bahnassy$
M. F. KhalaP
and
“Department of Microbiology, King Abdulaziz University Hospital. P.O. Box 6615, Jeddah-21452, TDepartment of Swgery, College of Medicine, k-ing Abdulaziz University, P.O. Box 9029, Jeddah-21413. JDepartment of Community Medicine and Primary Health Care, College of Medicine, King Abdulaziz University, P.O. Box 9029, yeddah-21413, Saudi Arabia. Accepted for publication
7 February
1992
Summary: A prospective study was made of 1418 surgical wounds at the 250-bed King Abdulaziz University Hospital in Jeddah, Saudi Arabia. Daily examinations of wounds, cultures of all suspicious wounds and 28 days outpatient clinic follow-up were performed. The overall infection rate was 9%. The infection rate after clean surgery was 9.5%. High rates of infections were noted after colon resection (19%), caesarean section (19%), abdominal hysterectomy (10%) and cholecystectomy (10%). The infection rates after appendectomy, mastectomy and herniorrhaphy were approximately 7%. A lower rate of infection was seen after thyroidectomy (2%). The incidence of infection was significantly related to pre-operative stay in hospital and to duration of operation.
Introduction
In spite of modern standards of preoperative preparation, antibiotic prophylaxis and advances in anaesthetic and operative techniques, postoperative wound infections still remain a major problem associated with significant morbidity and mortality. * Many factors affect the incidence of surgical wound infection, in addition to the surgeon’s skill and the hospital environment. Host attributes, such as age over 60 years, diabetes mellitus, malignant disease, obesity, malnutrition, length of preoperative stay or pre-existing infection may influence risk, as may such operation characteristics as site, urgency, duration and time of skin shaving.24 Surgical wound infection is the second most frequently encountered hospital-acquired infection at King Abdulaziz University Hospital (KAUH). This study reports a 2-year prospective postoperative wound Correspondence 0195-6701/92/050079+05
to: Dr A. T. A. Eltahawy. $03.00/O
0 I997 The Hoapd
79
Infection
Smery
80
A. T. A. Eltahawy
et al.
surveillance programme initiated in August 1987 at KAUH, which has 250 beds (92 surgical or gynaecological) and three operating theatres. The aim was to determine the rate of infection and the factors that influence the infection rate, to obtain statistical background for future investigation of variables and to improve our infection rate and bed utilization. Methods
All operations that were performed at KAUH between August 1987 and July 1989 were included except oral, rectal and vaginal operations, transurethral resection of the prostate, burn treatments and circumcisions. Wounds were observed by an infection control nurse daily during the patients’ stay in hospital. After discharge, wounds were inspected at each follow-up outpatient attendance and for at least 28 days postoperatively. Microscopy and aerobic and anaerobic cultures were performed on a specimen from any wound that appeared inflamed and demonstrated drainage of any type within 4 weeks of operation. The definition of wound infection proposed by the Centers for Disease Control was used. This requires purulent drainage or a positive culture or a deliberately opened wound or a surgeon’s diagnosis.5 Operations were classified into clean, clean-contaminated, contaminated and dirty as defined by the National Research Council.2 Information recorded on worksheets included the patient’s characteristics, such as age, sex, weight and underlying diseases, and patient-care variables such as preoperative hospitalization, hair removal, type of surgery, length of operation, presence of drains and type of drainage. The x2 test was used to test association between the infection rate and the length of the operation, the length of preoperative stay, insertion of drains and types of drainage. The t-test was used to compare the mean days of stay following the operation for both infected and non-infected wounds. Results
Over the 2-year study period, there were 127 wound infections in 1418 wounds, an overall infection rate of 9% (Table I). Infection rates for certain commonly performed surgical procedures are listed in Table II. Herniorrhaphy was the most common operation at KAUH, accounting for 21% of the operations performed. Cholecystectomy, caesarean section and of the appendectomy accounted for 16%) 15% and 5.5% respectively, operations carried out. High rates of infection were noted in the following operations: colon resection (18.7), caesarean section (18.7), abdominal hysterectomy (10.4%) and cholecystectomy (10.1). The infection rates after appendectomy, mastectomy and herniorrhaphy were 6.6%) 6.9% and 7.4% respectively. A low rate of infection was seen after thyroidectomy (1.9%). The frequency of recovery of the four most common organisms causing wound infection in the study were Staphylococcus aUreUS (41%), dominant
Postoperative Table
wound
I. Incidence
Classification of operative procedure5
78
Clean-contaminated Contaminated
81
of wound infection
Infected No. %
Clean
infection
Not infected No. %
Total
9.5
742
90.5
820
34
6.3
510
93.7
544
10
21.3
37
78.7
47
Dirty
5
71.4
2
28.6
7
Total
127
9.0
1291
91.0
1418
Table Type
II.
of operation
Appendectomy Cholecystectomy Caesarean section Abdominal hysterectomy Colon resection Herniorrhaphy Mastectomy Orthopaedic operations Splenectomy Thoracotomy Thyroidectomy Stomach and oesophagus operations Urological operations Others Total
Infection
rates for common surgical Infected No. % 5 22 39 5 6 21 4 8
procedures
Not infected No. %
Total
ii
6.6 10.1 18.7 10.4 19.4 7.4 6.9 4.6 0 0
71 196 170 43 25 262 54 165 14 4
93.4 89.9 81.3 89.6 80.6 92.6 93.1 95.4 100 100
76 218 209 48 31 283 58 173 14 4
01
01.9
53 54
98.1 100
:t
9 7 127
7.1 10.0 9.0
117 63 1291
92.9 90.0 91.0
126 70 1418
on sites other than the gastro-intestinal tract, Klebsiella and spp. (1 S%), Escherichia coli (12%) and Pseudomonas species (9%). A significant relationship between operations with a duration of more than 2 h and an increase in the postoperative wound infection rate was observed in patients undergoing cholecystectomy, mastectomy and appendectomy; the infection rates for operations of more than 2 h vs. less than 2 h were: cholecystectomy-54.6%, (12/22) vs. 25%, (49/196) [x2 = 8.57, P-C 0.011 mastectomy-SO% (2/4) vs. 5.6% (3/54) [corrected x2=455, P
operations
Enterobacter
82
A. T. A. Eltahawy
et al.
with 13% of patients without any infection (163/1291) [x2=6.16, P
The rates of infection in this study after ‘clean-contaminated’, and ‘contaminated’ procedures (6.3% and 21 “A) fall between the extremes reported by others. 6-l’ Infections were detected more frequently in wounds after ‘clean’ than after ‘clean-contaminated’ surgery (9.5% vs. 6.3%). Standard plenum ventilation is supplied to the operating theatres and instrument sterilization is regularly monitored. The deportment of the shows some deficiencies, such as improper surgical team, however, excessive traffic in the operating theatre, rough handling of masking, tissues, excessive talking by the surgical team and an excessive number of people in the theatre. Preoperative non-electric razor shaving, too, such as was used on all our patients, has been shown to be associated with a higher infection rate than depilatory treatment.” The duration of preoperative hospitalization has previously been shown to be a risk factor for postoperative wound infections,‘a9 as has a duration of relationship between the operation of more than 2 h. 12-14The significant type of drainage and infection rate in our study and the lack of significant association between insertion of any type of drain and infection are rates after appendectomy consistent with other reports. 3,8,15The infection and cholecystectomy are similar to those reported by others.‘a’6-19 The infection rate after cholecystectomy without exploration of common bile duct was 6% (11/180), significantly lower than the 29% rate (11/38) for cholecystectomy with exploration of the duct (PC 0.001). The infection rate after caesarean section compared favourably with that reported by Farber and Wenzel;17 on the other hand, their reported rate of infection after colon resection was considerably lower than our rate (12% vs. 19%). Approximately 40% (12/31) of patients with wound infections after ‘contaminated’ procedures and 57% (199/348) of those with wound infections after ‘clean-contaminated’ procedures in this study were given no antibiotic prophylaxis is indicated for such preoperative antibiotics; operations 20,21 Omission of preoperative antibiotics was noted in 60% (13 1j218) of patients who had cholecystectomy whose wounds later became infected (7%).
Postoperative
wound
infection
83
The results of this study serve as a base line for future comparison and emphasize the important economic as well as human consequences of surgical wound infection. They indicate some actions which need to be taken to improve the rates of infection after different types of surgery. We thank study.
Mrs
Layla
Tabash,
Infection
Control
Nurse,
for her excellent
assistance
in this
References M, Schwartz ML. Surgical wound infections. A S-year prospective 1. Olson M, O’Connor study of 20,193 wounds at the Minneapolis VA Medical Center. Ann Surg 1984; 199: 253-259. Academy of Sciences-National Research Council. Ad Hoc Committee of the 2. National Committee on trauma, Division of Medical Sciences. Postoperative Wound Infections: The influence of ultraviolet irradiation of the operating room and of various other factors. Ann Surg 1964; 160 (Suppl 2): 1-192. AIG. Clark C. Smith G. Postonerative wound infection: a commuter analvsis. 3. Davidson BrJ Surg 1971; 58: 333-336. 4. Edwards LD. The epidemiology of 2056 remote site infections and 1966 surgical wound infections occurring in 1865 patients. Ann Surp 1976; 184: 7588766. JS, Jarvis WR, Emori TG, Horan TC, Hughes JM. CDC definitions for 5. Garner nosocomial infections. Am r 1afect Control 1988; 16: 128-140. etiology, prevention and management. Surg Clin North Am 6. Todd JC. Wound infection: 1968; 48: 787-798. Service. The incidence of wound infections in England and 7. Public Health Laboratory Wales. Lancet 1960; 2: 659. study of 23,649 surgical wounds. Arch Surg 8. Cruse PJE, Foord R. A five-year prospective 1973; 107: 206-209. in hospitals: wound infections. r Hasp Infect 9. Report on the national survey of infection 1980; 2 (Suppl): 29934. patients at high risk of surgical 10. Haley RW, Culver DH, Morgan WM, et al. Identifying wound infection: a sample multi-variate index of patient susceptibility and wound contamination. AmJ Epidemiol. 1985; 121: 206-215. 11. Seropian R, Reynolds BM. Wound infections after preoperative depilatory versus razor preparation. AmJ Surg 1971; 121: 251-254. of wound infection: a lo-year prospective study 12. Cruse PJE, Foord R. The epidemiology of 62,939 wounds. Surg Clin N#orth Am 1980; 60: 27-40. wound infection. Predisposing factors and the effect of a 13. Brunn JN. Postoperative reduction in the dissemination of staphylococci. Acta Med Stand 1970; 514: (Suppl) l-89. sepsis. Mt Sinai J Med hTY 1970; 37: 14. Koota GM. A study of major postoperative 590-602. E, Stein H, Sacks TG, Shapiro M. Mitchel J. Multivariate analysis of 15. Simchen determinants of postoperative wound infection in orthopaedic patients. J Hosp Infect 1984; 5: 137-146. WA, Culbertson WR, Hummel RP. Surgical considerations of endogenous 16. Altemeier infection. Sources, types and methods of control. Surg Clin North Am 1968; 46: 2277240. RP. Postoperative wound infection rates: results of prospective 17 Farber BF, Wenzel, statewide surveillance. Am r Surg 1980; 140: 3433346. and bile culture in 800 consecutive 18 Reiss R, Eliashiv A, Deutsch A. Septic complication cholecystectomies. World J Surg 1982; 6: 195-199. J, Aho J. Wound infection in abdominal surgery. Act Chir Stand 19. Renvall S, Niinikoshi 1980; 146: 25-30. prophylaxis in surgical patients. Bull NY Acad 20. Gilbert DN. Current status of antibiotic Med 1984; 60: 340-357. 21. Kaufman Z, Englberg M, Eliashiv A, Reiss R. Systemic prophylactic antibiotic in elective billiary surgery Arch Surg 1984; 119: 100221004.