Walter C. Hellinger

Timing of Antimicrobial Prophylaxis and the Risk of Surgical Site Infections Results From the Trial to Reduce Antimicrobial Prophylaxis Errors

Objective:The objective of this study is to determine the optimal timing for surgical antimicrobial prophylaxis (AMP). Summary Background Data:National AMP guidelines should be supported by evidence from large contemporary data sets. Methods:Twenty-nine hospitals prospectively obtained information on AMP from 4472 randomly selected cardiac, hip/knee arthroplasty, and hysterectomy cases. Surgical site infections (SSIs) were ascertained through routine surveillance, using National Nosocomial Infections Surveillance system methodology. The association between the prophylaxis timing and the occurrence of SSI was assessed using conditional logistic regression (conditioning on hospital). Results:One-hundred thirteen SSI were detected in 109 patients. SSI risk increased incrementally as the interval of time between antibiotic infusion and the incision increased (overall association between timing and infection risk P = 0.04). When antibiotics requiring long infusion times (vancomycin and fluoroquinolones) were excluded, the infection risk following administration of antibiotic within 30 minutes prior to incision was 1.6% compared with 2.4% associated with administration of antibiotic between 31 to 60 minutes prior to surgery (OR: 1.74; 95% confidence interval, 0.98–3.04). The infection risk increased as the time interval between preoperative antibiotic and incision increased or if the antibiotic was first infused after incision. Intraoperative redosing (performed in only 21% of long operations) appeared to reduce SSI risk in operations lasting more than 4 hours (OR of 3.08 with no redosing; 95% confidence interval 0.74–12.90), but only when the preoperative dose was given correctly. Conclusions:These data from a large multicenter collaborative study confirm and extend previous observations and show a consistent relationship between the timing of AMP and SSI risk with a trend toward lower risk occurring when AMP with cephalosporins and other antibiotics with short infusion times were given within 30 minutes prior to incision.

Allograft Rejection Predicts the Occurrence of Late-Onset Cytomegalovirus (CMV) Disease among CMV-Mismatched Solid Organ Transplant Patients Receiving Prophylaxis with Oral Ganciclovir

The natural history of cytomegalovirus (CMV) disease associated with solid organ transplantation has been modified as a result of the widespread use of antiviral prophylaxis. Anecdotal reports have indicated a reduction of CMV disease at the expense of its later occurrence after completion of ganciclovir prophylaxis. The present study investigated the occurrence of CMV disease and its risk factors among 37 liver and kidney transplant recipients with CMV D+/R- status who received oral ganciclovir during the first 100 days posttransplantation. CMV disease occurred in 9 patients (24.3%) at a median of 144 days posttransplantation (range, 95-190 days). Allograft rejection was found to be strongly associated with the occurrence of late-onset CMV disease (risk ratio, 6.6; 95% confidence interval, 1.4-32.1; P=.02). Thus, CMV D+/R- solid organ transplant recipients receiving 3 months of oral ganciclovir who develop allograft rejection during the period of antiviral prophylaxis may benefit from extended and/or enhanced antiviral prophylaxis to prevent late-onset CMV disease.

Prevalence of Healthcare-Associated Infections in Acute Care Hospitals in Jacksonville, Florida

OBJECTIVE To determine healthcare-associated infection (HAI) prevalence in 9 hospitals in Jacksonville, Florida; to evaluate the performance of proxy indicators for HAIs; and to refine methodology in preparation for a multistate survey. DESIGN Point prevalence survey. PATIENTS Acute care inpatients of any age. METHODS HAIs were defined using National Healthcare Safety Network criteria. In each facility a trained primary team (PT) of infection prevention (IP) staff performed the survey on 1 day, reviewing records and collecting data on a random sample of inpatients. PTs assessed patients with one or more proxy indicators (abnormal white blood cell count, abnormal temperature, or antimicrobial therapy) for the presence of HAIs. An external IP expert team collected data from a subset of patient records reviewed by PTs to assess proxy indicator performance and PT data collection. RESULTS Of 851 patients surveyed by PTs, 51 had one or more HAIs (6.0%; 95% confidence interval, 4.5%-7.7%). Surgical site infections ([Formula: see text]), urinary tract infections ([Formula: see text]), pneumonia ([Formula: see text]), and bloodstream infections ([Formula: see text]) accounted for 75.8% of 58 HAIs detected by PTs. Staphylococcus aureus was the most common pathogen, causing 9 HAIs (15.5%). Antimicrobial therapy was the most sensitive proxy indicator, identifying 95.5% of patients with HAIs. CONCLUSIONS HAI prevalence in this pilot was similar to that reported in the 1970s by the Centers for Disease Control and Preventions Study on the Efficacy of Nosocomial Infection Control. Antimicrobial therapy was a sensitive screening variable with which to identify those patients at higher risk for infection and reduce data collection burden. Additional work is needed on validation and feasibility to extend this methodology to a national scale.

A randomized, prospective, double-blinded evaluation of selective bowel decontamination in liver transplantation.

Background. Bacterial infection is a frequent, morbid, and mortal complication of liver transplantation. Selective bowel decontamination (SBD) has been reported to reduce the rate of bacterial infection after liver transplantation in uncontrolled trials, but benefits of this intervention have been less clear in controlled studies. Methods. Eighty candidates for liver transplantation were randomly assigned in a double-blinded fashion to an SBD regimen consisting of gentamicin 80 mg+polymyxin E 100 mg+nystatin 2 million units (37 patients) or to nystatin alone (43 patients). Both treatments were administered orally in 10 ml (increasing to 20 ml, according to predefined criteria), four times daily, through day 21 after transplantation. Anal fecal swab cultures were performed on days 0, 4, 7, and 21. Rates of infection, death, and charges for medical care were assessed from day 0 through day 60. Results. More than 85% of patients in both treatment groups began study treatment more than 3 days before transplantation. Rates of infection (32.4 vs. 27.9%), death (5.4 vs. 4.7%), or charges for medical care (median

Carbapenems and Monobactams: Imipenem, Meropenem, and Aztreonam

194,000 vs.

Early and late onset Clostridium difficile-associated colitis following liver transplantation.

163,000) were not reduced in patients assigned to SBD. On days 0, 4, 7, and 21, growth of aerobic gram-negative flora in fecal cultures of patients assigned to SBD was significantly less than that of patients taking nystatin alone; growth of aerobic gram-positive flora, anaerobes, and yeast was not significantly different. Conclusion. Routine use of SBD in patients undergoing liver transplantation is not associated with significant benefit.

Outbreak of toxic anterior segment syndrome following cataract surgery associated with impurities in autoclave steam moisture

Imipenem and meropenem, members of the carbapenem class of beta-lactam antibiotics, are among the most broadly active antibiotics available for systemic use in humans. They are active against streptococci, methicillin-sensitive staphylococci, Neisseria, Haemophilus, anaerobes, and the common aerobic gram-negative nosocomial pathogens including Pseudomonas. Resistance to imipenem and meropenem may emerge during treatment of P. aeruginosa infections, as has occurred with other beta-lactam agents; Stenotrophomonas maltophilia is typically resistant to both imipenem and meropenem. Like the penicillins, the carbapenems have inhibitory activity against enterococci. In general, the in vitro activity of imipenem against aerobic gram-positive cocci is somewhat greater than that of meropenem, whereas the in vitro activity of meropenem against aerobic gram-negative bacilli is somewhat greater than that of imipenem. Daily dosages may range from 0.5 to 1 g every 6 to 8 hours in patients with normal renal function; the daily dose of meropenem, however, can be safely increased to 6 g. Infusion-related nausea and vomiting, as well as seizures, which have been the main toxic effects of imipenem, occur no more frequently during treatment with meropenem than during treatment with other beta-lactam antibiotics. The carbapenems should be considered for treatment of mixed bacterial infections and aerobic gram-negative bacteria that are not susceptible to other beta-lactam agents. Indiscriminate use of these drugs will promote resistance to them. Aztreonam, the first marketed monobactam, has activity against most aerobic gram-negative bacilli including P. aeruginosa. The drug is not nephrotoxic, is weakly immunogenic, and has not been associated with disorders of coagulation. Aztreonam may be administered intramuscularly or intravenously; the primary route of elimination is urinary excretion. In patients with normal renal function, the recommended dosing interval is every 8 hours. Patients with renal impairment require dosage adjustment. Aztreonam is used primarily as an alternative to aminoglycosides and for the treatment of aerobic gram-negative infections. It is often used in combination therapy for mixed aerobic and anaerobic infections. Approved indications for its use include infections of the urinary tract or lower respiratory tract, intra-abdominal and gynecologic infections, septicemia, and cutaneous infections caused by susceptible organisms. Concurrent initial therapy with other antimicrobial agents is recommended before the causative organism has been determined in patients who are seriously ill or at risk for gram-positive or anaerobic infection.

Risk stratification and targeted antifungal prophylaxis for prevention of aspergillosis and other invasive mold infections after liver transplantation

Clostridium difficile colitis (CDC) remains a serious and common complication after liver transplantation (LT). Four hundred and sixty‐seven consecutive LTs in 402 individuals were performed between 1998 and 2001 at our center. Standard immunosuppression consisted of tacrolimus, mycophenolate, and steroids. CD toxins A and B were detected by using a rapid immunoassay or enzyme immunoassay. CDC was diagnosed in 32 patients (5–1999 days post‐LT), with 93.8% (30/32) of patients developing CDC during the first year post‐LT; three individuals had CDC more than 3 years post‐LT, one of which also had early CDC. All patients presented with abdominal pain and watery diarrhea. Patients who developed CDC within 1‐year post‐LT were significantly more likely to have a hemorrhagic, biliary, or infectious complication. Patients who developed CDC within 28 days post‐LT had a significantly higher model end‐stage liver disease score. Treatment consisted of fluid and electrolyte replacement and metronidazole and no patients developed toxic megacolon, required colonic resection, or died from CDC. CDC represents a potentially severe complication following LT. Most cases occur early post‐LT. Development of a hemorrhagic, biliary, or infectious complication is associated with the development of CDC.

Intravascular Catheter-Related Bloodstream Infection

BACKGROUND Toxic anterior segment syndrome (TASS), a complication of cataract surgery, is a sterile inflammation of the anterior chamber of the eye. An outbreak of TASS was recognized at an outpatient surgical center and its affiliated hospital in December 2002. METHODS Medical records of patients who underwent cataract surgery during the outbreak were reviewed, and surgical team members who participated in the operations were interviewed. Potential causes of TASS were identified and eliminated. Feedwater from autoclave steam generators and steam condensates were analyzed by use of spectroscopy and ion chromatography. RESULTS During the outbreak, 8 (38%) of 21 cataract operations were complicated by TASS, compared with 2 (0.07%) of 2,713 operations performed from January 1996 through November 2002. Results of an initial investigation suggested that cataract surgical equipment may have been contaminated by suboptimal equipment reprocessing or as a result of personnel changes. The frequency of TASS decreased (1 of 44 cataract operations) after reassignment of personnel and revision of equipment reprocessing procedures. Further investigation identified the presence of impurities (eg, sulfates, copper, zinc, nickel, and silica) in autoclave steam moisture, which was attributed to improper maintenance of the autoclave steam generator in the outpatient surgical center. When impurities in autoclave steam moisture were eliminated, no cases of TASS were observed after more than 1,000 cataract operations. CONCLUSION Suboptimal reprocessing of cataract surgical equipment may evolve over time in busy, multidisciplinary surgical centers. Clinically significant contamination of surgical equipment may result from inappropriate maintenance of steam sterilization systems. Standardization of protocols for reprocessing of cataract surgical equipment may prevent outbreaks of TASS and may be of assistance during outbreak investigations.

Association of cytomegalovirus infection and disease with death and graft loss after liver transplant in high-risk recipients.

Antifungal prophylaxis has been proposed for liver transplant recipients at increased risk for invasive mold infection. Risk factors for invasive mold infection after liver transplantation were selected to divide recipients into 3 groups: (1) high risk—transplantation on hemodialysis or delay of hospital discharge beyond day 7 after transplantation because of allograft or renal insufficiency; (2) intermediate risk—retransplantation or transplantation for fulminant hepatic failure; (3) low risk—absence of conditions in groups 1 and 2. During an intervention period (February 1999–April 2001), prophylactic administration of a lipid complex of amphotericin (Abelcet) at 5 mg/kg intravenously every 24 to 48 hours was recommended for high‐risk recipients. The frequency of mold infection was compared to that of a preintervention period (February 1998–January 1999) when antifungal prophylaxis was not provided. During the intervention period, invasive mold infection developed in 2 (6%) of 35 high‐risk recipients, 0 of 28 intermediate‐risk recipients, and 1 (0.5%) of 187 low‐risk recipients. Overall, of 58 liver transplant recipients, 3 (5%) developed an invasive mold infection during the preintervention period, compared with 3 (1%) of 250 during the intervention period (P = 0.08). The only death from invasive mold infection occurred during the preintervention period. Rates of pulse corticosteroid treatment of rejection and cytomegalovirus infection were lower during the intervention period. In conclusion, readily identifiable patient characteristics can be used to stratify liver transplant recipients for risk of invasive mold infection. Antifungal prophylaxis given to high‐risk recipients may provide cost‐effective prevention of these infections. (Liver Transpl 2005;11:656–662.)