Twenty years of countermeasures against postoperative methicillin-resistant Staphylococcus aureus infections.

PURPOSE: A total of 7345 cases of digestive organ surgery were investigated over the course of 20 years. METHODS: Owing to the increasing incidence of methicillin-resistant Staphylococcus aureus (MRSA) infections, we classified our countermeasures into periods A (September 1987 to February 1990), B (March 1990 to February 1997), C (March 1997 to February 1999), D (March 1999 to October 2004), and E (November 2004 to August 2007), and compared the number of infections during these periods. In period B, cefazolin and cefotiam were administered as prophylaxis. The treatment continued for 4 days, including the day of surgery. The patients undergoing endotracheal intubation or tracheotomy were managed with nonscreening pre-emptive isolation and cohorting (NSPEI&C), regardless of whether MRSA was present. However, NSPEI&C was halted in period C, but it was thereafter implemented again, and prophylactic antibiotics were administered only on the day of surgery during period D. In period E, prophylactic antibiotics were administered for 3 days. RESULTS: In period A, MRSA was contracted in 4.1% (34/833) of patients. In period B, the MRSA isolation rate decreased to 0.3% (8/2722). In period C, the MRSA isolation rate increased to 3.4% (23/681). In period D, the MRSA isolation rate fell to 2.2% (40/1807). In period E, MRSA isolation cases significantly decreased to 0.4% (5/1302; P < 0.002 vs period D). CONCLUSION: The comprehensive management, selection of prophylactic antibiotics, and NSPEI&C were all considered to be effective.

Antibiotic time-lag combination therapy with fosfomycin for postoperative intra-abdominal abscesses.

The first-line treatment for intra-abdominal abscess is source control. Sometimes, however, source control is too invasive for relatively small abscesses and is not feasible due to the risk of injury to some organs. Based on reports that fosfomycin (FOM) can break up biofilms to enhance the permeability of other antibiotics, we investigated the FOM time-lag combination therapy (FOM-TLCT). We enrolled 114 patients who had intra-abdominal abscess after gastrointestinal surgery and examined the efficacy of FOM-TLCT using the same therapeutic antibiotic (TA) as that which had been used previously, but had proven ineffective, at the same dose schedule. The efficacy endpoint determination was carried out as follows: among the systemic inflammatory response syndrome (SIRS)-positive cases, even after administration of TA, excellent outcome was defined as SIRS negative within 7 days of FOM-TLCT with TA without the need for other treatment, including other antibiotics or drainage. Of the 114 patients enrolled, 104 cases (SIRS positive 73; SIRS negative 31) were assessed. Ten patients were excluded; four had received TA at higher doses, three had received different TAs, and three were considered to have bacteria resistant to TAs. Among these patients, 86.3% (63/73) of the SIRS-positive cases were classified as excellent, and 90.3% (28/31) of the SIRS-negative cases were classified as effective. In total, the efficacy rate was 87.5% (91/104). The total no-response rates were 12.5% (13/104). FOM-TLCT seems to be effective for treating refractory intra-abdominal abscess.

Prophylactic antibiotics given within 24 hours of surgery, compared with antibiotics given for 72 hours perioperatively, increased the rate of methicillin-resistant Staphylococcus aureus isolated from surgical site infections.

The purpose of this research was to find which method better prevented MRSA isolation from postoperative infection sites: the administration of postoperative infection control agents within 72 h of surgery, including the day of surgery, or the administration of these agents within 24 h of surgery. More than 3000 patients who underwent elective surgery of the digestive system were studied. Cefazolin or cefotiam was used as the prophylactic antibiotic. The number of patients, sex, age, clinical stage, incidence of surgical site infection (SSI), isolated bacteria, distal pancreatectomy with or without gastrectomy, the rate of laparoscopic surgery, and the rate of abdominoperineal resection (APR) were examined in a prospective controlled study over three time periods. There were no significant differences in the demographics of patients in the three periods. The duration of antibiotic administration was 96.1 +/- 11.2 h in period A, 18.2 +/- 2.7 h in period B, and 66.9 +/- 11.1 hours in period C (P < 0.05). There was no significant difference in the incidence of SSI in the three periods. Methicillin-resistant Staphylococcus aureus (MRSA) was isolated from the infectious site in 0.47% of patients in period A, and from 2.1% and 0.34% of patients in periods B and C, respectively, and the incidence of MRSA was significantly higher in period B as compared with periods A and C (P < 0.01). The isolation rates of MRSA and methicillin-sensitive S. aureus (MSSA) were both significantly higher in period B patients (P < 0.005). We concluded that the administration of prophylactic antibiotics within 24 h of surgery increased the rate of isolation of MRSA.

Isolated bacteria and drug susceptibility associated with the course of surgical site infections.

Bacterial culture is not often performed for mild surgical site infections, so only isolates from patients with severe surgical site infections have been identified. Consequently, broad-spectrum antibacterials, such as carbapenems, whose resistance has been highly modified, have been selected for use from the initial stage of these infections, and this is one reason for the increase in drug-resistant bacteria. We carried out this study to show antibiotics that are appropriate for each period of such infections. Bacteria obtained from postoperative infection sites in 114 patients with surgical site infections after gastrointestinal surgery were classified as first, second, third, and fourth isolates: the first isolates were taken when the administration of prophylactic antibiotics was finished, and the second, third, and fourth isolates were taken when the administrations of the first, second, and third therapeutic antibiotics, respectively, were finished. The incidence of drug-resistant strains was rare in strains isolated in the early phase of infections. The numbers of strains resistant to cephems and carbapenems increased as the clinical course of the infection progressed. New broad-spectrum antibiotics such as carbapenems should not be selected for the treatment of early-phase surgical site infections.

Success of countermeasures against respiratory infection after digestive surgery by strict blood and fluid resuscitation.

This prospective controlled study included 5859 cases of digestive surgery from September 1987 to August 2002. The study was divided into six 2.5-year periods, A-F. During and after period B, cefazolin was used for surgery of the esophagus, stomach, and gall bladder, and cefotiam for colon resection, hepatectomy, and pancreatectomy. During period A, total parenteral nutrition (TPN) was administered for 6 (+/-4.6) days before surgery, on average. During and after period B, TPN was confined to patients who were incapable of oral intake. During thoracic esophageal cancer surgery, frozen plasma was administered at 10 ml/h, colloid osmotic pressure was maintained, and water was prevented from accumulating in the third space. Mechanical respiratory support was not needed during or after period B. The incidence rate of respiratory infection decreased to 1.7% during period A, and to 0.7%-1.1% during and after period B. During and after period B, in particular, early respiratory infection cases after surgery decreased significantly to 0.1%-0.3%. In period A, among the respiratory infectious bacteria isolated, MRSA was the most frequent, followed by Pseudomonas aeruginosa. After period B, P. aeruginosa was the most frequent bacterium isolated. Over all periods, there was no significant difference in resistant ratios in P. aeruginosa. Because of consistent infusion management during the perioperative period, artificial breathing became unnecessary and, as a result, the prevalence of early respiratory infection decreased significantly.

Questionnaire on perioperative antibiotic therapy in 2003: postoperative prophylaxis.

We distributed a questionnaire to institutions accredited by the Japan Surgical Society asking about the use of antibiotics in digestive tract surgery in Japan in 2003, and compared the results with those of a similar questionnaire distributed in 1993. The period of antibiotic administration for esophageal resection was at least 6 days in 64.9% of the 1993 questionnaire responses, but less than 4 days in 60.4% of the present questionnaire responses. For distal gastrectomy, antibiotics were given for 5 days postoperatively at 53.0% of the responding institutions in the 1993 survey, but for only 3 days, at 72.4%, in the present survey. An oral antibiotic was given as part of antibacterial colon preparation before colon resection at 70% or more of the institutions in the 1993 survey, while no antibiotic colon preparation was given at 80% of the institutions in the present survey. The period of antibiotic administration for laparoscopic cholecystectomy was at least 4 days in 72% of the institutions in the 1993 survey, but this decreased remarkably to fewer than 2 days at 80.8% of the institutions in the current survey. There were no differences in the selection of antibiotics between the two surveys. The period of antibiotic administration has decreased remarkably in the last decade.

Drug susceptibility of isolates from severe postoperative intraperitoneal infections causing multiple organ failure.

PURPOSE: To select the most appropriate antibiotic regimens for life-threatening postoperative infections, we obtained isolates from patients with severe postoperative infections over a 12-year-period, and examined their drug susceptibility. METHODS: The subjects of this study were 55 patients with multiple organ failure (MOF) caused by postoperative infection. RESULTS: All strains of Methicillin-resistant Staphylococcus aureus (MRSA) were susceptible to Vancomycin (VCM) and Teicoplanin (TEIC). Only 0.3% of all the Pseudomonas aeruginosa strains were resistant to Imipenem (IPM), but 53.6% of the strains from the severe infections were resistant to IPM. On the other hand, there were few P. aeruginosa strains resistant to Meropenem (MEPM), Ceftazidime (CAZ), Ciprofloxacin (CPFX), and Pazufloxacin (PZFX), even among strains isolated from severe infections. The resistant rate of Bacteroides fragilis to Clindamycin (CLDM) was 35.9%, but there were strains resistant to IPM and Panipenem. CONCLUSION: These findings suggest that VCM or TEIC are most appropriate for severe abdominal abscess caused by MRSA, whereas MEPM, CAZ, CPFX, and PZFX are more effective against P. aeruginosa infections. The only antibiotic effective against B. fragilis infections in this study was IPM.

Recovery of the susceptibility of isolated bacterium achieved by giving long-established antibiotics as prophylaxis against postoperative infections.

PURPOSE: To evaluate the effectiveness of operative antibiotic therapy we changed the antibiotics and examined the susceptibility of the postoperative infection. METHODS: We studied 4 593 patients who underwent gastrointestinal surgery during the last 12.5 years, and examined the changes in intraoperative antibiotics, the return of bacteria isolated from infectious sites, the trends in frequency of Methicillin-resistant Staphylococcus aureus (MRSA) isolation, and changes in the antibiotic susceptibility of Pseudomonas aeruginosa and Bacterioides fragilis. We changed the antibiotics to Cefazolin (CEZ) for upper gastrointestinal tract surgery and cholecystectomy, and to Cefotiam (CTM) for colonic, liver, and pancreatic surgery. We also reduced the period of drug administration. RESULTS: The rate of MRSA infections decreased, the rate of P. aeruginosa infections was always under 20% and the rate of B. fragilis infections increased. After the guidelines of drug susceptibility were prepared, the minimum inhibitory concentrations (MICs) of Cefsulodin (CFS) and Piperacillin (PIPC) for P. aeruginosa and of Latamoxef (LMOX) and PIPC for B. fragilis, decreased. CONCLUSION: The use of antibiotics considered comparatively old for the prophylaxis of postoperative infection prevented the emergence of MRSA-like resistant strains, influenced changes in Gram-negative bacteria drug susceptibility, and led to an overall reduction in multiple drug resistance.

[Surgical site infection: SSI].

Surgical site infection(SSI) is any infection originating in surgical wounds or the organs/spaces opened or manipulated during an operative procedure, and it is the most common postoperative complication. The definition of SSI is clearly standardized in the Centers for Disease Control and Prevention(CDC) guidelines. The degree of intra-operative contamination is important as a risk factor of SSI, and it is classified into clean, clean-contaminated, contaminated, and dirty/infected. Preventative measures for SSI, such as pre-, intra-, and postoperative infection control, are described in detail in the CDC guidelines. It is not an overstatement to say that how well SSI is controlled is the conclusive factor in good postoperative results.