Prophylaxis of postoperative infections

Review of the Current Antibiotic Guidelines used in Dermatologic Surgery

Antibiotics have been used as a prophylaxis for dermatologic procedures. We will review the various procedures that specific antibiotics with dosages are used for, depending on the procedure, diagnosis, and circumstance of the patient. We will examine the current and updated guidelines used in dermatologic surgery and the overlapping guidelines across other fields. Physicians must consider the side effects of antibiotics and the resistance that may occur as a result before using the class or level of prophylaxis. Initial evaluation for alcohol, chlorhexidine or iodine should be measured as well. Updated guidelines aim to address the contraindications of antibiotics, yet further research is needed to avoid antibiotic resistance and to explore alternative methods of antibiotic application, such as intranasal and intravenous. This article is protected by copyright. All rights reserved.

Reduction of risk of infection during elective laparoscopic cholecystectomy using prophylactic antibiotics: a systematic review and meta-analysis

BACKGROUND

Whether perioperative administration is required in elective laparoscopic cholecystectomy (LC) in patients with low risk of infection remains controversial.

OBJECTIVE

To investigate whether perioperative use of prophylactic antibiotics during elective LC can reduce the incidence of postoperative infection using a meta-analysis.

METHODS

Pubmed, Cochrane Library, Embase, and reference lists were searched up to October 26, 2020, for randomized controlled trials (RCTs) of the perioperative use of antibiotics during LC. A systematic review with meta-analysis, meta-regression, and GRADE (Grading of Recommendations Assessment, Development and Evaluation) of the evidence was conducted. The Cochrane (RoB 2.0) tool was used to assess the risk of bias.

RESULT

A total of 14 RCTs were ultimately included in the meta-analysis, involving a total of 4360 patients. The incidence of surgical site infections, distant infections, and overall infections was investigated and the relationship with the perioperative use of prophylactic antibiotics during LC analyzed. The results indicated that in low-risk patients undergoing elective LC, prophylactic antibiotics reduce the incidence of surgical site infections (RR 0.66; 95% CI 0.45-0.98), with a moderate GRADE of evidence, distant infections (RR 0.34; 95% CI 0.16-0.73), with a low GRADE of evidence and overall infections (RR 0.57; 95% CI 0.40-0.80), with a moderate GRADE of evidence.

CONCLUSIONS

The present meta-analysis demonstrates that the perioperative use of antibiotics in LC is effective in low-risk patients, possibly reducing the incidence of surgical site infections, distant infections, and overall infections. However, in view of the limitations of the study, it is recommended that studies with a more rigorous design (for downgraded factors) and larger sample size should be conducted in the future so that the conclusions above can be further verified through key result indicators.

Can post-operative antibiotic prophylaxis following elective laparoscopic cholecystectomy be completely done away with in the Indian setting? A prospective randomised study

Premise and Objective:

Elective laparoscopic cholecystectomy (LC) has low risk for post-operative infectious complications; still most clinicians use persistent post-operative prophylactic antibiotics out of habit, tradition, or simply as defensive practice due to evolving medicolegal implications of a large number of surgeries being showcased as daycare or next day discharge procedures. This randomised prospective trial was done to test the need for such prophylaxis in cases of elective LC in a rural/semi-urban setting.

Materials and Methods:

Two hundred and ten successive patients undergoing elective LC were randomised into groups receiving single dose of injection ceftriaxone at the time of induction of anaesthesia, (Group A = 112 cases) and those who in addition to above received injection ceftriaxone twice daily for 2 days postoperatively (Group B = 98 cases). Post-operative infectious complications between two groups were compared for variables such as age, sex, body mass index and bile/stone spillage.

Results:

There was no significant difference in surgical site infection rates between the groups for variables such as age, sex, body mass index, duration of symptoms, American Society of Anesthesiologists grade, duration of surgery and hospital stay. Intraoperative spillage of stones (9.8% [A]: 5.1% [B]) did not increase infectious complications even in the presence of positive bile culture (Group A, N = 7 vs. Group B, N = 3). An operative time of greater than 60 min was found to be associated with increased surgical site infection (P = 0. 0006).

Conclusion:

Single dose of ceftriaxone at the time of induction is adequate prophylaxis following elective LC even in the rural/semi-urban Indian setting and routine continued administration of antibiotic should be abandoned as it contributes to adverse reactions, drug resistance and unnecessary financial burden.

Review of Pure Endoscopic Full-Thickness Resection of the Upper Gastrointestinal Tract

Natural-orifice transluminal endoscopic surgery (NOTES) using flexible endoscopy has attracted attention as a minimally invasive surgical method that does not cause an operative wound on the body surface. However, minimizing the number of devices involved in endoscopic, compared to laparoscopic, surgeries has remained a challenge, causing endoscopic surgeries to gradually be phased out of use. If a flexible endoscopic full-thickness suturing device and a counter-traction device were developed to expand the surgical field for gastrointestinal-tract collapse, then endoscopic full-thickness resection using NOTES, which is seen as an extension of endoscopic submucosal dissection for full-thickness excision of tumors involving the gastrointestinal-tract wall, might become an extremely minimally invasive surgical method that could be used to resect only full-thickness lesions approached by the shortest distance via the mouth. It is expected that gastroenterological endoscopists will use this surgery if device development is advanced. This extremely minimally invasive surgery would have an immeasurable impact with regard to mitigating the burden on patients and reducing healthcare costs. Development of a new surgical method using a multipurpose flexible endoscope is therefore considered a socially urgent issue.

The Effect of Prophylactic Antibiotics on Post Laparoscopic Cholecystectomy Infectious Complications: A Double-Blinded Clinical Trial

Background

Laparoscopic cholecystectomy (LC) is one of the most common surgeries in laparoscopic surgery. Although, it is believed that LC has low-risk for post-operative infectious complications, the use of a prophylactic antibiotic is still controversial in elective LC.

Objective

To determine the impact of prophylactic antibiotics on postoperative infection complications in elective laparoscopic cholecystectomy.

Methods

In this double-blind, placebo-controlled, randomized, clinical trial, patients who were candidates for elective LC, from March 2012 to 2015, in four hospitals in Babol, Iran, were studied. Patients were allocated randomly to two groups, i.e., group C: Cefazolin (n = 182) and group P: placebo (n = 247). Group C received 1 g of Cefazolin 30 minutes before anesthesia and and then, six and 12 hours after anesthesia. Group P patients received 10 ml of isotonic sodium chloride solution. Age, gender, type of gallbladder diseases (stone, polyp, or hydrops), the length of post-operative hospitalization, frequency of gallbladder rupture, the duration of surgery, and the kinds of complications associated with infections were collected for each patient in the two groups. The data were analyzed by IBM-SPSS version 20, using the t-test and the chi-squared test, and a p-value < 0.05 was considered as significant.

Results

There were no significant differences between the two groups in terms of gender (C versus P: 18 (9.9%) male versus 22 (9%); p = 0.74), age (C versus P: 43.75 + 13.30 years versus 40.91 + 13.05; p = 0.20), and duration of surgery (C versus P: 34.97 ± 8.25 min versus 34.11 ± 8.39; p = 0.71). There were no significant differences between the two groups in the incidences of post-operative infection (C versus P: 3 (1.7%) versus 5 (2%); p = 0.99) and rupture of the gallbladder (C versus P: 14 (7.8%) versus 17 (6.8%); p = 0.85). No other post-operative systemic infectious complications (e.g., sepsis, pneumonia, or urinary tract infection) were found in either group.

Conclusion

For patients who underwent laparoscopic cholecystectomy (LC), prophylactic antibiotics had no important role in the prevention of infections; so these antibiotics apparently are not necessary in treatment, and they are not recommended for patients with laparoscopic cholecystectomy as low-risk selective antibiotics.

Trial registration

The trial was registered at the Iranian Clinical Trial Registry (http://www.irct.ir) with the IRCT identification number IRCT2013070413865N1.

Funding

This research was supported financially by the Research Council of Babol University of Medical Sciences.

A randomized prospective study of oral levofloxacin vs intravenous flomoxef prophylaxis in postoperative infection after endoscopic sinus surgery

OBJECTIVE

The clinical efficacy and cost effectiveness of oral antimicrobial prophylaxis with levofloxacin (LVFX) on endoscopic sinus surgery (ESS) was evaluated.

MATERIALS AND METHODS

Ninety-three patients undergoing ESS were prospectively enrolled in the present study. The patients were randomly divided into 2 groups, LVFX and flomoxef (FMOX). Two hundred milligrams of LVFX was orally given 2 hours before the start of surgery and 6 hours after the end of surgery, which was followed by the administration of 200 mg every 12 hours for 2 days. One gram of FMOX was dissolved in 100 ml of physiological saline and given intravenously at the induction of anesthesia and 6 hours after the end of surgery, followed by infusion twice daily for 2 days.

RESULTS

There were no statistically significant differences between 2 groups in terms of age, sex, systemic complications, surgical procedures, the duration of the operation, the length of hospitalization, the amount of blood loss, body temperature, or the number of white blood cells or C-reactive protein. Although no statistical significance was observed in the bacterial resistance between the two antibiotics, LVFX seems to show a low rate of resistance pattern change as compared to FMOX. The present study demonstrated that no patients treated with LVFX or FMOX were afflicted with postsurgical infection.

CONCLUSION

Oral administration of LVFX is a simple, cost-effective and safe alternative to intravenous prophylaxis in ESS based on clinical efficacy and bacteriological study.

Role of pathogenic oral flora in postoperative pneumonia following brain surgery

BACKGROUND

Post-operative pulmonary infection often appears to result from aspiration of pathogens colonizing the oral cavity. It was hypothesized that impaired periodontal status and pathogenic oral bacteria significantly contribute to development of aspiration pneumonia following neurosurgical operations. Further, the prophylactic effects of a single dose preoperative cefazolin on the oral bacteria were investigated.

METHODS

A matched cohort of 18 patients without postoperative lung complications was compared to 5 patients who developed pneumonia within 48 hours after brain surgery. Patients waiting for elective operation of a single brain tumor underwent dental examination and saliva collection before surgery. Bacteria from saliva cultures were isolated and periodontal disease was scored according to type and severity. Patients received 15 mg/kg cefazolin intravenously at the beginning of surgery. Serum, saliva and bronchial secretion were collected promptly after the operation. The minimal inhibitory concentrations of cefazolin regarding the isolated bacteria were determined. The actual antibiotic concentrations in serum, saliva and bronchial secretion were measured by capillary electrophoresis upon completion of surgery. Bacteria were isolated again from the sputum of postoperative pneumonia patients.

RESULTS

The number and severity of coexisting periodontal diseases were significantly greater in patients with postoperative pneumonia in comparison to the control group (p = 0.031 and p = 0.002, respectively). The relative risk of developing postoperative pneumonia in high periodontal score patients was 3.5 greater than in patients who had low periodontal score (p < 0.0001). Cefazolin concentration in saliva and bronchial secretion remained below detectable levels in every patient.

CONCLUSION

Presence of multiple periodontal diseases and pathogenic bacteria in the saliva are important predisposing factors of postoperative aspiration pneumonia in patients after brain surgery. The low penetration rate of cefazolin into the saliva indicates that its prophylactic administration may not be sufficient to prevent postoperative aspiration pneumonia. Our study suggests that dental examination may be warranted in order to identify patients at high risk of developing postoperative respiratory infections.

American Society of Anesthesiologists classification of physical status as a predictor of wound infection

BACKGROUND

Wound infection occurs when bacterial contamination overcomes the hosts' defences against bacterial growth. Wound categories are a measurement of wound contamination. The American Society of Anesthesiologists (ASA) classification of physical status may be an effective indirect measurement of the hosts' defence against infection. This study examines the association between the ASA score of physical status and wound infection.

METHODS

A retrospective review of a prospective study of antibiotic prophylaxis was carried out. Patients with a documented ASA score who received optimal prophylactic antibiotics were included. The anaesthetist scored the ASA classification of physical status in theatre. Other risk factors for wound infection were also documented. Patients were assessed up to 30 days postoperatively.

RESULTS

Of 1013 patients there were 483 with a documented ASA score. One hundred and one may not have received optimal prophylaxis, leaving a database of 382 patients. There were 36 wound infections (9.4%). Both the ASA classification of physical status (P = 0.002) and the wound categories (P = 0.034) significantly predicted wound infection. The duration of surgery, patient's age, acuteness of surgery and the organ system being operated on did not predict wound infection. On logistic regression analysis the ASA score was the strongest predictor of wound infection.

CONCLUSION

When effective prophylactic antibiotics were used the ASA classification of physical status was the most significant predictor of wound infection.

Vascular Graft Infection by Staphylococcus aureus: Efficacy of Cefazolin, Teicoplanin and Vancomycin Prophylaxis Protocols in a Rat Model

OBJECTIVES

Prophylactic efficiencies of cefazolin, teicoplanin and vancomycin in a dacron graft infection model caused by methicillin-susceptible (MSSA) or -resistant Staphylococcus aureus (MRSA) were investigated.

DESIGN

Prospective, randomized, controlled animal study.

MATERIALS AND METHODS

Infections were established subcutaneously in the back of rats by implantation of Dacron prostheses followed by topical inoculation onto grafts of MSSA or MRSA. Experimental groups were as follows: Uncontaminated group (control), MSSA- or MRSA-contaminated and untreated groups, MSSA- or MRSA-contaminated groups treated with cefazolin, teicoplanin or vancomycin by one of three regimens (one day, two days, or three days regimen). Grafts were removed 7 days after the implantation and evaluated by using sonication and quantitative blood agar culture.

RESULTS

Contaminated groups demonstrated graft infections. Cefazolin, teicoplanin and vancomycin profoundly prevented the graft infections in MSSA- or MRSA-contaminated groups. For each antibiotic regimen, the most effective prevention was achieved by the drugs given as three days regimen. For MSSA and MRSA, the order of the effectiveness was as follows: teicoplanin>vancomycin>cefazolin.

CONCLUSION

As a prophylactic agent, teicoplanin seems to be more effective than vancomycin and cefazolin against vascular graft infections caused by MSSA and MRSA in rats.

The impact of prophylactic antibiotics on postoperative infection complication in elective laparoscopic cholecystectomy: a prospective randomized study

BACKGROUND

The aim of this prospective randomized study was to investigate the necessity and impact of prophylactic antibiotics on postoperative infection complications in elective laparoscopic cholecystectomy.

METHODS

At the time of induction of anesthesia, group A patients (n = 141) received 1 g cefazolin, and group B patients (control; n = 136) received 10 mL isotonic sodium chloride solution. Patients' characteristics and general operative outcomes were compared and analyzed.

RESULTS

The overall rate of infection was 1.1% for total 277 patients (0.7% for group A patients and 1.5% for group B patients). No significant difference in infection complications was found between these 2 groups. Also any risk factors contributing to infection complications could not be found.

CONCLUSIONS

We do not recommend the use of prophylactic antibiotics in elective laparoscopic cholecystectomy because they will not decrease the already-low rate of postoperative infectious complications.

A comparison of the prophylactic efficacy of ceftriaxone and cefotaxime in abdominal surgery

BACKGROUND

Although ceftriaxone (R) and cefotaxime (C) are highly effective antibiotics, few studies have directly compared their prophylactic efficacy.

METHODS

In a prospective, randomized, double blind study of 1,013 patients undergoing abdominal surgery, the prophylactic use of ceftriaxone and cefotaxime were compared. Intravenous cephalosporin, 1 g, was given at induction of anesthesia, with intravenous metronidazole, 500 mg, also being given for colorectal surgery.

RESULTS

The difference in wound infection (R 8%, C 12%, P <0.05) was due to appendicectomies not receiving metronidazole, (R 6%, C 18%, P <0.03) and was no longer present when these cases were excluded from analysis (R 8%, C 10%). Of note chest and urinary tract infection (R 6%, C 11%, P <0.02) and "any" infection (R 20%, C 27%, P <0.05) were reduced with ceftriaxone.

CONCLUSIONS

Both antibiotics provide comparable wound prophylaxis as long as metronidazole is added for colorectal and appendiceal surgery. Ceftriaxone may be more versatile having the additional apparent benefits of reducing other postoperative infections, being less dependent on metronidazole as an adjunct and providing a more effective prophylactic cover against Staphylococcus aureus.

Protocol implementation in hospital infection control practice: an Italian experience of preoperative antibiotic prophylaxis

This study evaluates the effectiveness of a protocol implemented to induce behavioural modifications in healthcare workers (HCWs). A preoperative antibiotic prophylaxis protocol for surgical procedures in clean and clean-contaminated wounds was used. The study was conducted in a 300-bed Italian university hospital between 1998 and 1999. The protocol's impact was analysed by retrospective examination of the clinical records for selected common surgical procedures. The study also investigated the reasons for the low compliance with the protocol through a focus group methodology. We examined 723 surgical procedures and the overall compliance was 30.8% (56/182) before the implementation of the protocol and 45.2% (76/168) after 1 year (P< or = 0.01). During the same period compliance with the use of antibiotics increased when antibiotics were recommended by the protocol (5/115 vs. 19/109, P< or = 0.01) and use decreased when they were not (51/67 vs. 57/59, P< or = 0.01). As reported in the focus groups, reasons for low compliance included hospital policy weaknesses in protocol definition and implementation and the cultural behaviour of HCWs. Our results reinforce previous findings that monitoring the effectiveness of protocol implementation in the medical care setting is essential. Critical points that might increase the effectiveness of protocol implementation have also been identified.

Antibiotic prophylaxis in surgery: summary of a Swedish-Norwegian Consensus Conference

This consensus document sets out proposals for antibiotic prophylaxis in abdominal, urological, gynaecological, orthopaedic, vascular and thoracic surgery. As far as possible the recommendations are based on prospective controlled trials. However, for some procedures, e.g. lung surgery and implantation of pacemakers, documentation is lacking but antibiotic prophylaxis is given traditionally. The choice of antibiotics is generally conservative, emphasizing that antibiotics used for therapy should be avoided in prophylactic regimens. Most recommendations are for the use of a first- or second-generation cephalosporin or an isoxazolyl penicillin, when necessary, combined with a nitroimidazole derivative (metronidazole or tinidazole). Suggestions are given for more frequent use of orally administered antibiotics, such as co-trimoxazole, doxycycline, metronidazole or tinidazole. Emphasis is put on short-term prophylaxis. In most cases surgical antibiotic prophylaxis should be given as a single dose and in no case should the prophylaxis time exceed 24 h.

A comparison of teicoplanin versus cephradine plus metronidazole in the prophylaxis of post-operative infection in vascular surgery

A total of 272 patients were enrolled into this prospective, unblinded, randomized comparison of single-dose teicoplanin vs three doses of cephradine plus metronidazole as prophylaxis for vascular surgery at St James's and Seacroft Hospitals, Leeds, UK. In all, 71.3% of patients (194/272) were enrolled at St James's University Hospital. Patients received either a single dose of teicoplanin, 6 mg/kg i.v., or cephradine, 1 g i.v. with metronidazole, 1 g rectally, at induction of anaesthesia followed by two further 1 g doses of cephradine and metronidazole 8 and 16 hours later. There were 136 patients in each treatment group. The most common operations were femoropopliteal grafts (96) and aortic aneurysm repairs (47). In the 'intention-to-treat' analysis, primary wound infections were seen in 4.4% of patients (6/136) receiving teicoplanin and 5.9% of patients (8/136) receiving cephradine plus metronidazole (95% CI -6.7%, +3.8%). Other disturbances to wound healing occurred in 23 patients (11 in the teicoplanin and 12 in the cephradine plus metronidazole group). Secondary respiratory tract infections occurred in 17 patients (8 receiving teicoplanin and 9 receiving cephradine plus metronidazole). In the evaluable patients analysis, primary wound infections occurred in 3.5% of patients (4/114) receiving teicoplanin and 5.1% of patients (6/117) receiving cephradine plus metronidazole. Staphylococcus aureus and Proteus sp. were the most common pathogens in primary wound infections. Despite the absence of Gram-negative cover in the teicoplanin group, Gram-negative infections occurred more often in the cephradine plus metronidazole group. Surgery of the lower extremities carried the highest risk of post-operative infection. Rates of infection were significantly higher at Seacroft Hospital (P = 0.001), and significantly higher for cephradine plus metronidazole between the two hospitals (P = 0.0008). Adverse events occurred in 40 patients receiving teicoplanin (29.4%) and 39 patients receiving cephradine plus metronidazole (28.7%). In 19 patients receiving teicoplanin (14%) and 15 receiving cephradine plus metronidazole (11%) these events were considered to be related to the study drugs. The most often reported events were infections, cardiac events and vascular phenomena (haematoma or emboli). Marked changes in haematological parameters and liver function tests were noted seven days after operation in patients in each treatment group, but these resolved quickly as the effects of the operation subsided. ESR remained elevated in both groups at the six-month follow-up assessment. It is concluded from this two-centre study that a single dose of teicoplanin shows similar efficacy to a three-dose regimen of cephradine plus metronidazole as prophylaxis for wound infection in vascular surgery. Both regimens were well tolerated, and there was an equal incidence of adverse events in the two regimens, which reflected the poor general health status of this elderly study population.

Single-dose cefodizime as infection prophylaxis in abdominal surgery: a prospective multicenter study

This prospective pilot study was performed to evaluate the efficacy, safety and tolerability of a single dose of cefodizime as infection prophylaxis in patients undergoing major abdominal surgery. One hundred forty-nine patients received 2g cefodizime, a third-generation cephalosporin, 30 min before abdominal surgery. The mean operation time was 116 +/- 66 min. Eighteen patients received metronidazole additionally. In 8/149 patients (5.4%) the final outcome was considered to be a treatment failure. 94.6% of the patients had no signs of infection. The long half-life of cefodizime allows a single-dose perioperative prophylaxis even in abdominal surgery lasting 3 to 4 h. Cefodizime can be regarded as a safe antibiotic prophylaxis with few side effects.

Antibiotics for the acute abdomen

Antibiotics are only an adjunct to proper surgical therapy for the treatment of the acute abdomen associated with bacterial secondary peritonitis. Upon presentation, all patients require a preoperative dose of antibiotics for prophylaxis against infection of remaining sterile tissues. Patients found intraoperatively to have an established peritoneal infection benefit from an immediate postoperative course of therapeutic antibiotics. A regimen that adequately covers facultative and aerobic gram-negative bacilli and anaerobic organisms is essential. The duration of therapeutic antibiotics is probably best decided on an individual patient basis. The goal of antibiotics is to reduce the concentration of bacteria invading tissues. The pathogens of bacterial peritonitis are influenced by such factors as the patient's pre-existing chronic diseases, state of acute physiologic debilitation, immunocompetence, recent antibiotic use, recent hospitalization, and neutralization of gastric acidity. Intraoperative peritoneal cultures are most useful in patients suspected of having impaired local host defenses. In these patients, all identified organisms, such as Enterococcus or Candida, may be potential pathogens. The common practice of administering empiric and prolonged courses of broad-spectrum antibiotics in patients who manifest persistent signs of inflammation may be more harmful than beneficial. These patients warrant an exhaustive search for extra-abdominal and intraperitoneal sources of new infection. Otherwise, such use of antibiotics may continue to promote the selection of bacteria that are highly resistant to conventional antibiotics and permit the overgrowth of organisms commonly seen with tertiary peritonitis. The best chance of resolving bacterial peritonitis is through early, aggressive surgical management complemented by short courses of potent antibiotics and appropriate physiologic support. Through these efforts, the clinician tries to help the systemic inflammatory response to benefit the host and not become unregulated, result in MOFS, and produce a high mortality.

Is single-dose antibiotic prophylaxis sufficient for coronary artery bypass surgery? An analysis of peri- and postoperative serum cefuroxime and vancomycin levels

Preliminary findings have suggested that a single intravenous dose of antibiotic is effective for infection prophylaxis in cardiac surgery. However there are still insufficient data on this proposed regimen. We measured serum cefuroxime and vancomycin levels after three different dosage regimens, in patients undergoing coronary artery bypass grafting (CABG). Sixty patients were randomized into three cefuroxime and three vancomycin groups with 10 patients in each: a group given a one-day course, or an additional dose during cardiopulmonary bypass or a single dose. Serum levels of the antibiotics were measured at various times throughout the operative procedure and until 48 h after the start of prophylaxis. Each of the six dosage regimens maintained serum levels adequate for infection prophylaxis throughout the operative procedure. Serum levels remained above 2 mg/L for more than 8 h postoperatively, even in the single-dose cefuroxime group and above 4 mg/L for more than 24 h with all the vancomycin dosage regimens. Thus a single dose of cefuroxime (3 g or 1.5 g) or vancomycin (1.5 g) seems to achieve and maintain serum levels sufficient for infection prophylaxis several hours after CABG procedures.

Prevention of surgical infections in dogs with a single intravenous injection of marbofloxacin: an experimental model

Eighteen healthy beagle dogs of both sexes were each given 0, 2 or 4 mg/kg marbofloxacin intravenously before the subcutaneous implantation of a silicon tissue cage. Two millilitres of a suspension containing 1.3 x 10(4) colony forming units (CFU)/ml of Staphylococcus intermedius were then injected into the cage 15 minutes after the intravenous injection. The dogs were clinically assessed immediately, and then two, four, eight and 24 hours after the challenge. Samples of inflammatory fluid were harvested at the same times in order to count staphylococci and to assay marbofloxacin concentrations. Blood samples were taken in order to assay plasma marbofloxacin levels. The staphylococcal counts were lower in both treated groups than in untreated dogs (P < 0.01). All the clinical criteria were similar in the three groups. The concentration of marbofloxacin was similar in plasma and inflammatory fluid. Both doses were well tolerated and no adverse reactions were observed.

Prophylactic antibiotics in cataract operations

The rationale for prophylactic antibiotics in cataract operations must be continually reevaluated in light of cost-effectiveness and adverse reactions. The principles learned from wound infections associated with general surgical procedures should be applied to the limited knowledge about the rare event of endophthalmitis. Herein the literature on experimental and clinical wound infections in general surgical procedures is reviewed, with analysis of microbial flora, pathophysiology of wound infections, and pharmacokinetics of antibiotics. Experimental and clinical studies on prophylactic antibiotics to prevent endophthalmitis are reviewed, including information on topically applied antibiotics, chemical antisepsis, and administration of subconjunctival, intracameral, and systemic antibiotics. In addition, the benefits, limitations, and risks of the various types of prophylactic antibiotics are discussed. Because of the limited data on prophylactic antibiotics in cataract operations, providing dogmatic statements is difficult. General recommendations are offered based on the currently available literature, and a stratified approach is suggested based on wound construction and number of anterior segment maneuvers.