Prophylactic antibiotics in elective colorectal surgery

A randomized prospective study was conducted on 194 patients who underwent elective colorectal surgery for carcinoma. All patients received the same mechanical bowel preparation. In addition, patients in group A received oral neomycin and erythromycin base; patients in group B received systemic metronidazole and gentamicin, while patients in group C received both oral and systemic antibiotics. Postoperative septic complications related to colorectal surgery occurred in 27.4 per cent, 11.9 per cent and 12.3 per cent respectively in groups A, B and C (chi 2 = 7; P less than 0.05). The incidence of sepsis in groups B and C was almost identical. Patients who received oral antibiotics alone (group A) had significantly higher risks of postoperative sepsis when compared with patients in either group B or group C (P less than 0.05). As there is no additional advantage of combining oral and systemic antibiotics, we recommend systemic metronidazole and gentamicin to be used with mechanical bowel preparation in elective colorectal surgery.     

Wound sepsis following gastrointestinal surgery: a comparison of topical and two-dose systemic cephradine.

A prospective study of the effect of the route of administration of prophylactic antibiotic on the wound infection rate following gastrointestinal surgery was performed. Patients were randomly allocated to one of three groups: group 1 received no form of antibiotic prophylaxis; group 2 received 1 g of cephradine applied topically to the wound at closure; group 3 received 1 g of cephradine intravenously at induction of anaesthesia and a further intravenous dose of 500 mg 4 h later. Wound infections occurred in 12 of 83 patients in the control group (14.5 per cent), in 6 of the 83 patients in the group who received topical antibiotic (7.2 per cent) and in 3 of the 82 patients who received systemic antibiotics (3.6 per cent). Only the group who received systemic antibiotic showed a statistically significant reduction in the incidence of wound infections compared with the control group (P = 0.03).     

Combined topical povidone-iodine and systemic antibiotics in postappendicectomy wound sepsis

Three hundred and fifteen patients with appendicitis were randomized into two groups. One group received pre-operative systemic gentamicin and metronidazole while the other group received 1 per cent topical povidone-iodine solution in addition to the antibiotics. For early appendicitis including normal and acutely inflamed appendices, only one dose of antibiotics was used. The postoperative wound sepsis was very low in both groups of patients and there was no statistical difference between them. For late appendicitis including gangrenous and perforated appendices, the antibiotics were continued for 7 days. Eight out of 51 patients who had the topical agent developed wound sepsis compared with one out of 52 patients who received no topical agent. This difference is statistically significant (P = 0.03). All wound infections presented within 2 weeks of operation and were deep. Povidone-iodine, 1 per cent, adversely affects the wound infection rate in late appendicitis and should not be used.     

Relationship between bile colonization, high-risk factors and postoperative sepsis in patients undergoing biliary tract operations while receiving a prophylactic antibiotic. West of Scotland Surgical Infection Study Group

A prospective audit of 644 patients undergoing biliary tract operations has been conducted to assess the incidence of bile colonization and its association with the incidence of postoperative sepsis when all patients received the same prophylactic antibiotic. The accuracy of the determination of high-risk factors has been assessed as has the correlation between bile colonization and patients assessed as 'high risk'. Organisms were cultured from the bile of 121 (19 per cent) patients and among these the incidence of wound or intra-abdominal sepsis was 22 per cent whereas among patients with sterile bile the incidence was only 2 per cent (P less than 0.0001). Although the incidence of bile colonization within the high-risk group (32 per cent) was more than twice that in the low-risk group (14 per cent), more than half (54 per cent) of the patients with positive bile cultures were in the low-risk group. It is concluded that, despite prophylactic antibiotics, bile colonization remains the major factor associated with postoperative sepsis, but that this cannot be predicted accurately by preoperative assessment of high-risk factors. Furthermore, we believe that a policy of selective administration of prophylactic antibiotics solely to high-risk patients cannot be justified.     

Postoperative prophylactic use of progesterone in renal cell carcinoma

Medroxyprogesterone acetate has been used prophylactically in 35 patients with stages I and IIIA renal cell carcinoma who had undergone radical nephrectomy. Metastasis was noted in 26 per cent (9 of 35) of the patients who had received the drug and in 44 per cent (20 of 45) of those who had not (controls). The incidence of metastasis in patients who had undergone nephrectomy more than 3 years previously was 10 per cent (3 of 31) for patients who received medroxyprogesterone acetate and 35 per cent (15 of 43) for the control group, the difference being statistically significant. Prognosis tended to be better in patients who had received medroxyprogesterone acetate than in the controls, and relative 3 and 5-year survival rates being 99.3 and 87.2 per cent, respectively, in the former group, and 86.8 and 75.0 per cent, respectively, in the latter group. There was no significant difference between these 2 groups. However, it may be concluded that prophylactic medroxyprogesterone acetate seems to be beneficial in the prevention of postoperative metastasis of renal cell carcinoma.     

A prospective trial of prophylactic antibiotics in hand lacerations.

A series of 368 patients with hand lacerations which required suturing were randomly allocated to one of three treatment groups. The incidence of infected and of imperfectly healed wounds was noted 7 days after suturing. As well as the influence of antibiotics on healing, sixteen other factors which it was considered might affect healing were analysed. The overall infection rate was 9-8 per cent, and there was no significant difference between the three groups. The imperfect healing rate (which includes the infected cases) was 24-6 per cent. There was a lower rate (P less than 0-05) of imperfect healing in the Triplopen group (15 per cent) than in either the flucloxacillin group (29-5 per cent) or the group who received no antibiotics (29-0 per cent). Other factors associated with imperfect healing found to be significant at the 1 per cent level, were wound contamination, pain and the presence of a wet or changed dressing at the second examination.     

Laparoscopic ventral hernia repair: postoperative antibiotics decrease incidence of seroma-related cellulitis

Seroma formation has been documented as a common complication in laparoscopic ventral herniorraphy. However, there are no recent studies documenting the incidence of or protective strategies against seroma-related cellulitis. The purpose of this study was to evaluate 65 laparoscopic ventral herniorraphies and to determine if seroma-related cellulitis can be prevented by the routine use of postoperative prophylactic antibiotics. A retrospective case review of 65 laparoscopic ventral herniorraphies was done at our institution from February 2002 to January 2004. All were performed using either Gore-Tex DualMesh or Bard Composix mesh and performed under the direct supervision of a single surgeon. Twenty patients received only preoperative third-generation cephalosporins or fluoroquinolones. All other patients received either 7 days of postoperative oral cephalosporins or fluoroquinolones in addition to preoperative antibiotics. Sixty-five patients underwent laparoscopic ventral hernia repair. There were 45 patients in the postoperative antibiotic group and 20 patients in the preoperative-only antibiotic group. Twenty-one patients developed seromas. Twelve of these developed cellulitis. The rates of seroma formation were similar in the two groups with 30 per cent in the preoperative only group and 33 per cent in the postoperative antibiotic group. However, 100 per cent of the seromas in the preoperative antibiotic group developed seroma-related cellulitis. Only 40 per cent of seromas in the postoperative antibiotic group developed cellulitis. In addition, two seromas in the preoperative antibiotics-only group progressed to frank mesh infection necessitating operative removal. There were no complications related to antibiotic administration. Laparoscopic ventral hernia repair is a safe and effective procedure. Our seroma rate is 30 per cent and compares equally with prior reported studies. Seroma-related cellulitis is a common problem that can lead to mesh infection, postoperative morbidity, and further need for operative care. The administration of 7 days of postoperative prophylactic antibiotics appears to be a safe and effective means to limit seroma-related cellulitis.     

A clinical study of postoperative infections following open-heart surgery: Occurrence and microbiological findings in 782 cases

A total 782 consecutive patients underwent open-heart surgery with CPB between January, 1979 and December, 1988, at the Yamagata University Hospital. We assessed the incidence of postoperative infections in relation to age, the duration of surgery and antibiotic prophylaxis, and examined the causative organisms, after which the types of infecting flora were compared between the 1st period, from 1979 to 1983 and the 2nd period, from 1984 to 1988.Postoperative infection occurred in 104 of the 782 patients (13.3 per cent); in the form of a wound infection in 41 (5.2 per cent), pneumonia in 33 (4.2 per cent), urinary tract infection in 9 (1.2 per cent), prosthetic valve endocarditis in 6 (0.8 per cent), and other infections in 15 (1.9 per cent). Patients aged under 12 months or over 60 years showed a higher incidence of infection, being 17.4 per cent and 19.2 per cent, respectively. Patients who underwent an operation of over 8 hours duration also had a significantly higher incidence compared to those whose operation time was less than 4 hours, being 32.9 per cent and 6.3 per cent, respectively (p<0.0001). There was no significant difference in the incidence of postoperative infection between patients given or not given preoperative prophylaxis. A total 123 species of organisms were isolated from the 104 patients, 52.8 per cent being gram-negative bacteria (GNB), and 43.9 per cent grampositive bacteria (GPB), and a remarkable increase in the incidence of GPB was seen in the 2nd period compared to the 1st period from 31.7 per cent to 50.0 per cent.There has been a recent increase in the number of high risk patients compromised by the severity of an underlying disease. Thus, to control infection, the surgical environment and aseptic technique seem more important than antibiotic prophylaxis.     

Randomized clinical trial of single- versus multiple-dose antimicrobial prophylaxis in gastric cancer surgery

BACKGROUND: The optimum duration of antimicrobial prophylaxis in elective gastric cancer surgery is still open to question. This multicentre randomized clinical trial compared a single-dose with a multiple-dose regimen of antimicrobial prophylaxis for prevention of surgical-site infection. METHODS: Between May 2001 and December 2004, 501 patients undergoing elective surgery for gastric cancer in ten centres were allocated randomly to single- or multiple-dose antimicrobial prophylaxis. The primary outcome measure was the incidence of surgical-site infection, analysed by intention to treat. RESULTS: Some 243 patients who received a single dose and 243 who received multiple doses of antibiotics were included in the final analysis. The surgical-site infection rate was 9.5 per cent (23 of 243) and 8.6 per cent (21 of 243) respectively (difference 0.9 (95 per cent confidence interval - 4.3 to 5.9) per cent). Antimicrobial prophylaxis had no major adverse effects. CONCLUSION: The incidence of surgical-site infection in elective gastric cancer surgery was similar with both antibiotic prophylaxis regimens.     

Intravesical Bacille Calmette-Guérin Eradicates Bacteriuria in Antibiotic-naïve Bladder Cancer Patients

Background

Intravesical bacille Calmette-Guérin (BCG) therapy is safe and effective in bladder cancer patients who have asymptomatic bacteriuria. BCG induces robust immune responses in the bladder that are responsible for its antitumor effect. We hypothesize that BCG-induced inflammation may eradicate bacterial infection.

Objective

To investigate whether intravesical BCG therapy alone can eradicate bacterial infection in antibiotic-naïve bladder tumor patients who have asymptomatic bacteriuria.

Design, setting, and participants

A single-institution prospective cohort study of bacteriuric adults with non–muscle-invasive bladder tumors who underwent outpatient BCG therapy or surveillance cystoscopy.

Intervention

Ninety high-risk patients received induction intravesical BCG without maintenance BCG, and 95 low-risk patients who had not received BCG underwent outpatient surveillance cystoscopy. Each patient had significant bacteriuria on urine culture, and none received routine antibiotics before, during, or after procedures.

Outcome measurements and statistical analysis

Urine cultures were repeated after 3, 6, and 12 mo. All patients had follow-up cystoscopy every 3 mo and were followed for a minimum of 1 yr. The end point was number of BCG-treated and cystoscopy patients who became bacteria free at 3, 6, and 12 mo.

Results and limitations

Two BCG-treated patients (2.2%) and six patients after cystoscopy (6%) developed febrile urinary tract infection (p = 0.21). All resolved with antibiotics. No patient was admitted for sepsis. Of 88 infected patients who received BCG without routine antibiotics, 58 (66%) were continuously bacteria free at 1 yr compared with 16 of 89 cystoscopy patients (18%; p = 0.001). The prospective observational study design prohibits causal inference of antibacterial effects attributed to BCG over cystoscopy.

Conclusions

Intravesical BCG therapy is associated with clearance of uropathogens in bladder cancer patients, possibly due to augmented innate host immunity.     

Should Antibiotics Be Given Prior to Outpatient Cystoscopy? A Plea to Urologists to Practice Antibiotic Stewardship

BackgroundAntimicrobial resistance is a major health problem, caused primarily by overuse of antibiotics in clinical situations in which they are not necessary. Practice guidelines recommend that antibiotics be given before outpatient cystoscopy to prevent symptomatic urinary tract infection (UTI).ObjectiveTo determine the frequency of febrile UTI after outpatient flexible cystoscopy in antibiotic-naive bladder tumor patients.Design, setting, and participantsA total of 2010 consecutive outpatients with bladder tumors were entered into a prospective registry study. All patients underwent cystoscopy after they submitted a voided urine sample for culture. Significant bacteriuria was defined as >10⁴ colony-forming units per milliliter with a single organism. Patients were stratified for known risk factors for UTI.InterventionPatients underwent flexible cystoscopy and received no antibiotics immediately before or after cystoscopy. They were followed for 30 d for onset of febrile UTI.Outcome measurements and statistical analysisThe end point was incidence of febrile UTI within 30 d of cystoscopy. Febrile UTI was defined as temperature >38 °C and dysuria, or having received antibiotics from an outside physician for urinary symptoms.Results and limitationsOf the 2010 patient cystoscopies, 489 (24%) had asymptomatic bacteriuria, and 1521 (76%) had sterile urine. Thirty-nine patients (1.9%) developed febrile UTI ≤30 d after cystoscopy—4.5% in colonized patients and 1.1% in uninfected patients (p = 0.02). All UTIs resolved in ≤12–24 h with oral antibiotics. None of the patients was admitted for bacterial sepsis. Limitations of the study are that it is a single-surgeon experience in one institution, and results may not apply to other patient populations.ConclusionsAntibacterial therapy before outpatient flexible cystoscopy does not appear necessary in bladder tumor patients who have no clinical signs or symptoms of acute UTI, including asymptomatic bacteriuria. Antibiotic stewardship is the responsibility of all urologists.     

Recurrences during the chemoprophylactic treatment of superficial tumors of the bladder

A total of 88 patients who underwent resection for superficial stages Ta and T1 bladder tumors received chemoprophylactic treatment to prevent recurrence postoperatively. The first 44 patients were given doxorubicin at monthly intervals and the second 44 received doxorubicin plus mitomycin C alternately, with the first 6 instillations at weekly intervals and the rest monthly beginning 1 month after resection. Recurrences during treatment were assessed as an index of drug resistance. Tumor developed while the patients were undergoing treatment (9 to 10 months) in 15.9 per cent (7 of 44) of group 1 patients, 18.1 per cent (8 of 44) of group 2 patients and 17.0 per cent (15 of 88) of the total patients studied. At the initial post-treatment cystoscopy 12 to 16 months later 2 more patients in group 1 and none in group 2 had recognizable tumors. Treatment was continued in patients with recurrences. A total of 41 recurrences in 435 months of followup was recorded, for a rate of 9.42 recurrences per 100 patient-months. No worsening of the histological grading was noted but 2 patients with initial stage T1 disease had subsequent carcinoma in situ.     

The influence of lower urinary tract infection on the recurrence rate of superficial transitional cell carcinoma of the bladder

We studied retrospectively 78 patients with recurrent superficial bladder tumors in an effort to determine whether transitional tumor cells implant and grow preferentially in patients who have undergone endoscopic resection of stage T1 bladder tumors in the presence of an inflamed urothelium. Of the patients 32 (group 1) had an undetected lower urinary tract infection at the time transurethral resection was performed and 46 (group 2) were free of infection. All patients had intravesical chemotherapy by thiotepa (triethylenethiophosphoramide) and were treated with appropriate antibiotics as soon as the urinary tract infection was recognized from 24 to 48 hours postoperatively. Of the patients in group 1, 37.5 per cent had tumor recurrence in less than 6 months and 15.6 per cent in less than 3 months, compared to 30.4 and 6.5 per cent, respectively, in group 2. Although the tumor recurrence rates 3 and 6 months postoperatively were higher among the group 1 patients (with urinary tract infection) the difference between the 2 groups was not significant. Because the patients were treated by intravesical chemotherapy, and antibiotics in those with urinary tract infection, our study does not allow a definite conclusion regarding the contribution of urinary tract infection on the recurrence rate of superficial bladder tumors.     

The diagnosis and management of infection following instrumented spinal fusion

A 10-year retrospective audit. (1) The incidence of infection; (2) causative organisms; (3) whether eradication of infection is achievable with spinal implant retention; (4) patient outcome. The reported incidence of infection following posterior spinal instrumentation is between 2.6 and 3.8%. Management of infection is controversial, with some advocating serial wound debridement while others report that infection cannot be eradicated with retention of implants. There are no published data demonstrating that propionibacteria are associated with early postoperative infection. The management of infected cases at our institution includes eventual removal of their implants. Our population was identified by studying the case notes of all patients who had undergone removal of spinal implants and cross-referencing this population with positive microbiology or histology reports. The incidence of infection was 3.7%. Propionibacteria were isolated in 45% of cases. The diagnosis of infection was unexpected in 25% of patients, following removal of implants for prominence of implants or back pain. Sixty per cent of patients with acute postoperative deep wound infection had continuing active infection on subsequent removal of implants, despite long-term antibiotics and wound debridement. Fourty-six per cent of patients had a stable, pain-free spine at the end of their treatment. This is the largest reported series of infections following posterior spinal instrumented fusions of which we are aware. Propionibacteria are a common cause of infection and successful eradication of infection cannot be reliably achieved with antibiotics and wound debridement alone.     

The role of long-term antibiotics in the prevention of infection in postoperative cardiac surgeries

Objective: To compare the effect of long-term (7 days) versus short-term (2 days) postoperative antibiotics in preventing postoperative infective complications in patients who have undergone open-heart surgeries. Design: Interventional, randomized controlled trial (RCT). Place and Duration of Study: Department of Cardiac Surgery, Dow University of Health Sciences, from February 2006 to July 2006. Patients and Methods: Cardiac patients (n=42), operated for valvular disease (36%), coronary artery bypass grafting (50%), or septal repair (14%), were included in our study. Patients were prospectively randomized into two groups. Group A (n=21) patients received oral antibiotics for 7 days, whereas group B (n=21) patients were given the same for 2 days postoperative. Pre-operative and intra-operative variables were equal in both groups. Total leukocyte count and temperature were monitored daily until the patients were discharged. The chest and leg wounds were inspected daily for any signs of infection. Sputum and urine cultures were sent for selected patients in case of respiratory tract infection or urinary tract infection, respectively. Each patient was followed until the next routine visit in outpatient department. Results: In group A, 3 patients (14%), developed infection postoperatively, whereas in group B, 13 patients (62%) (p =0.001) had to be started on oral or intravenous antibiotics as a result of developing either wound infection, a positive sputum culture, a positive urine culture or a localized infection elsewhere. Mean ward stay in group A was 4.8 +/- 4.5 days and in group B 6.5 +/- 4.1 days (p =0.011). Conclusion: In this series, there was a significantly higher frequency of infection and longer hospital stay in patients who received antibiotics for 2 days postoperatively as compared to those who received antibiotics for 7 days.     

High prevalence of abdominal aortic aneurysm in men with peripheral vascular disease: screening by ultrasonography

A study was carried out to see if an ultrasonic examination of the abdominal aorta was indicated in every patient who attended an outpatient clinic with peripheral vascular disease (PVD). One hundred consecutive patients were studied and compared with a control group. The incidence of abdominal aortic aneurysm (AAA) in the control group was 2 per cent. In the study group, the male patients had an incidence of 20 per cent of aneurysm and ectasia, while the female patients had an incidence of 12 per cent. Of all the abnormal aortas found by ultrasound, only 31 per cent were palpable clinically. Two aneurysms that required operation were found, while the remainder are to be followed by regular ultrasound assessment. Further studies are necessary to conclude if screening of a high risk group, such as patients with PVD, is worthwhile.     

Clinical characteristics and outcomes of surgical patients with vancomycin-resistant enterococcal infections

The purpose of this study is to determine risk factors associated with mortality in surgical patients with vancomycin-resistant enterococcus (VRE) infections. The hospitalizations of surgical patients with VRE infections from January 1998 to December 2001 were reviewed. Statistical analysis was performed using the Student's t test, chi square, and Fisher's exact test. Thirty-one surgical patients (male:female, 14:17) with a mean age of 51.9 years (range, 21-83 years) developed VRE infection. Infections included bacteremia (12), urinary tract (11), surgical site (seven), and soft tissue (five) infections and intra-abdominal abscess (one). Nine (29.0 per cent) patients received recent outpatient antibiotics and 20 (64.5 per cent) were on steroids. Fifteen (48.4 per cent) patients were treated with intravenous vancomycin before infection. Twelve (38.1 per cent) patients died with a trend toward advanced age (60.7 vs 46.5 years; P = 0.06). The incidence of VRE infection in kidney transplant patients was 1.8 per cent. Six transplant patients (five kidney and one kidney/ pancreas) developed VRE infections with four deaths. Hypertension (P = 0.04), coronary artery disease (P = 0.02), and the need for intra-arterial pressure monitoring (P = 0.04) were associated with mortality. Isolate location, gender, diabetes, renal dysfunction, respiratory disease, liver disease, and serum albumin were not associated with mortality. Kidney transplant patients have a high incidence of VRE infection. Surgical patients with VRE infections have a high mortality rate. Hypertension and coronary artery disease are risk factors for mortality.     

Short-term prophylactic antibiotics in patients undergoing prostatectomy: report of a double-blind randomized trial with 2 intravenous doses of cefotaxime

The effect of short-term antibiotic prophylaxis on postoperative infection with 2 injections of cefotaxime begun preoperatively was evaluated in a double-blind, randomized, placebo-controlled trial at 1 center on 181 patients with preoperative sterile urine undergoing transurethral resection (90) or open prostatectomy (91). Antibiotic prophylaxis reduced the number of urinary infections significantly in both groups without altering the level of resistant pathogens. Cefotaxime lowered the incidence of postoperative infection in the early postoperative period from 30 to 4 per cent in the transurethral resection group and from 46 to 4.5 per cent in the open prostatectomy group. A significant difference was found between the 2 treatment groups in the incidence of perioperative bacteremia and postoperative fever. Among the patients undergoing an open prostatectomy a reduced rate of wound infection and a shorter duration of hospital stay were witnessed in the treated group. Thus, short-term chemoprophylaxis by cefotaxime is of benefit in reducing morbidity and hospital cost for prostatectomy by either procedure.     

Comparison of staple-line leakage and hemorrhage in patients undergoing laparoscopic sleeve gastrectomy with or without Seamguard

Laparoscopic sleeve gastrectomy (LSG) has been recognized as a primary procedure for the surgical management of morbid obesity. Staple-line leaks and hemorrhage are two associated complications. Staple-line buttressing materials have been suggested to decrease these complications. When used during LSG, few published papers exist that compare the incidence of leak or hemorrhage to that of nonreinforced staple-lines. The purpose of this study was to compare the incidence of leak and hemorrhage in patients who did and did not receive reinforcement with Seamguard (W.L. Gore & Associates, Flagstaff, AZ). This is a retrospective analysis of patients undergoing LSG. All patients met National Institutes of Health criteria and each had an extensive preoperative evaluation. Data was collected from inpatient and outpatient medical records. Fifty-nine patients received reinforcement and 80 patients did not. There was no significant difference in mean body mass index, age, or gender make-up between the two groups. The overall incidence of leak was 3.60 per cent. The incidence was 3.39 per cent in patients who received reinforcement and 3.75 per cent in those who did not. This was not statistically significant. There was no incidence of staple-line hemorrhage in either group. There is no conclusive evidence that Seamguard reduces staple-line leakage or hemorrhage. Studies involving a larger number of patients are necessary before recommending staple-line reinforcement.     

Timing of prophylactic antibiotics in abdominal surgery: trial of a pre-operative versus an intra-operative first dose

When prophylactic antibiotics are used in abdominal surgery it is customary to give the first dose before the operation. Whilst intra-operative antibiotics may be effective in elective surgery, there may be an advantage to starting pre-operatively when there is already an infective focus such as appendicitis. Antibiotics started pre-operatively (group P) have been compared with antibiotics started after initial abdominal exploration (group T). Three intravenous doses of 500 mg metronidazole plus 1 g cephazolin were given in a randomized, double-blind study of 700 emergency and elective high-risk abdominal operations. Antibiotic plasma concentrations at the end of the operation were significantly lower in group P but lay well within the therapeutic range. Wound infection rates, which included minor and delayed infections, were similar in both groups (group P, 57 of 342, 16.7 per cent; group T, 55 of 358, 15.4 per cent; 95 per cent confidence intervals for the difference being -4.1 to +6.7 per cent. In appendicitis, wound infection rates were 12.1 and 13.9 per cent for groups P and T respectively. However, non-fatal deep sepsis was more common in group P (nine cases) than in group T (two cases) (chi 2 = 4.9, P less than 0.05). Postoperative infection was twice as common in obese patients whose body mass index (BMI) was greater than or equal to 26 (39 of 132, 30 per cent) than in thin patients whose BMI was less than 24 (41 of 288, 14 per cent; chi 2 = 13.8, P less than 0.001). This study failed to show any advantage to starting antibiotics pre-operatively, even in appendicitis.