Combined topical and systemic antibiotic prophylaxis in acute appendicitis

Risk Factors for Postoperative Infections Following Appendectomy of Complicated Appendicitis: A Meta-analysis and Retrospective Single-institutional Study

Patients with complicated appendicitis have an increased risk for postoperative infections. Potential risk factors for postoperative infections through a meta-analysis and retrospective chart review are discussed. A meta-analysis consisting of 35 studies analyzing complicated appendicitis treated with an appendectomy noting at least 1 postoperative infection was performed. A retrospective review was then conducted in patients diagnosed with complicated appendicitis after appendectomy. Of 5326 patients in total, 15.4% developed postoperative infections. Laparoscopic surgery and perioperative hyperoxygenation were found to be protective factors for the development of infection. Retrospectively, 53.2% of patients presented with complicated appendicitis. Patients with complicated appendicitis were more likely to be older in age and have an increased length of stay. Patient demographics, operative time, and comorbid status had no effect on postoperative infection or readmission rate. Physicians should strongly consider minimally invasive techniques to treat all cases of complicated appendicitis irrespective of comorbidities, age, sex, or body mass index.

Efficacy and safety of intrawound antibiotics in patients undergoing posterior spinal fusion for adolescent idiopathic scoliosis: a nationwide database study

PURPOSE

To assess the efficacy and safety of intrawound antibiotics in posterior fusions for adolescent idiopathic scoliosis (AIS).

METHODS

The NSQIP-Pediatric databases 2016-2018 were utilized. Patients 10 years of age or older with AIS who underwent posterior fusion were selected and divided into two cohorts based on the receipt of intrawound antibiotics. Patient characteristics and complications were compared. Multivariate analyses were performed to determine the efficacy and safety of intrawound antibiotics.

RESULTS

A total of 4203 patients received intrawound antibiotics while 879 patients did not. The intrawound antibiotic group had longer constructs, higher blood loss, and longer operative times, factors historically associated with higher infection rates. Those that received intrawound antibiotics had SSI rate of 0.69%, while its counterpart had 0.57% (p = 0.689). The reoperation rates were 1.12% and 1.25% (p = 0.735), for those with and without intrawound antibiotics, respectively. In multivariate analyses, intrawound antibiotics use was not found to be a significant predictor for SSI, any complications, reoperation and readmission.

CONCLUSION

The current study represents the largest AIS surgery cohort studied to evaluate the efficacy of intrawound antibiotics. Our analysis failed to demonstrate association between the use of intrawound antibiotics and reduction in SSI. While other studies have reported seroma, wound dehiscence and renal failure with the practice, we did not observe an increased rate of such complications. This study highlights the difficulty of understanding the role for individual infection prevention measures in current surgical settings, where the SSI rate for the control group was substantially lower than 1%.

Use of Topical Antibiotics before Primary Incision Closure to Prevent Surgical Site Infection: A Meta-Analysis

Background: Surgical site infections (SSIs) remains a concern for surgeons because of the negative impact on outcomes and health care costs. Our purpose was to assess whether topical antibiotics before primary incision closure reduced the rate of SSIs. Methods: Systematic review of MEDLINE/PubMed, Scopus, CINAHL, and Web of Science databases from inception to January 2017. Only randomized controlled trials (RCTs) were retrieved. The primary outcome was the SSI rate. Meta-analysis was complemented with trial sequential analysis (TSA). Results: Thirty-five RCTs (10,870 patients) were included. Only β-lactams and aminoglycosides were used. A substantial reduction of the incidence of SSIs with the application of antibiotic agents before incision closure (risk ratio [RR] 0.49, 95% confidence interval [CI] 0.37-0.64) was found, which remained in the analysis of 12 RCTs after removal of studies of uncertain quality. The use of β-lactams was effective to reduce SSI in elective surgery only (RR 0.33, 95% CI 0.13-0.85). In clean-contaminated fields and as an irrigation solution, β-lactams did not reduce the risk of SSI. Aminoglycosides were not effective (RR 0.74, 95% CI 0.49-1.10). After TSA, the evidence accumulated was far below the optimal information size. The heterogeneity of studies was high and methodological quality of most RCTs included in the meta-analysis was uncertain. Conclusions: Results of this meta-analysis show the data present in the literature are not sufficiently robust and, therefore, the use of topical β-lactams or aminoglycosides before incision closure to reduce SSI cannot be recommended or excluded.

Use of Intrawound Antibiotics in Orthopaedic Surgery

Intrawound antibiotics have been used in orthopaedic surgery procedures to prevent the development of surgical site infections. Local delivery of antibiotic powder has demonstrated a notable reduction in surgical site infection in rabbit and rodent in vivo models, as well as in other surgical fields, including vascular, colorectal, cardiothoracic, and dermatologic surgery. Intrawound antibiotic powder has been used in many orthopaedic applications, including spine surgery, total joint arthroplasty, trauma, foot and ankle reconstruction, and elbow surgery. Although the theory behind the use of intrawound antibiotic powder is promising, it has potential adverse effects, including antibiotic resistance, circulatory collapse, and decreased bone healing. In addition, most studies in the orthopaedic literature on the use of intrawound antibiotic powder are retrospective in nature.

Intracavity lavage and wound irrigation for prevention of surgical site infection

BACKGROUND

Surgical site infections (SSIs) are wound infections that occur after an operative procedure. A preventable complication, they are costly and associated with poorer patient outcomes, increased mortality, morbidity and reoperation rates. Surgical wound irrigation is an intraoperative technique, which may reduce the rate of SSIs through removal of dead or damaged tissue, metabolic waste, and wound exudate. Irrigation can be undertaken prior to wound closure or postoperatively. Intracavity lavage is a similar technique used in operations that expose a bodily cavity; such as procedures on the abdominal cavity and during joint replacement surgery.

OBJECTIVES

To assess the effects of wound irrigation and intracavity lavage on the prevention of surgical site infection (SSI).

SEARCH METHODS

In February 2017 we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE; Ovid Embase and EBSCO CINAHL Plus. We also searched three clinical trials registries and references of included studies and relevant systematic reviews. There were no restrictions on language, date of publication or study setting.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) of participants undergoing surgical procedures in which the use of a particular type of intraoperative washout (irrigation or lavage) was the only systematic difference between groups, and in which wounds underwent primary closure. The primary outcomes were SSI and wound dehiscence. Secondary outcomes were mortality, use of systemic antibiotics, antibiotic resistance, adverse events, re-intervention, length of hospital stay, and readmissions.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion at each stage. Two review authors also undertook data extraction, assessment of risk of bias and GRADE assessment. We calculated risk ratios or differences in means with 95% confidence intervals where possible.

MAIN RESULTS

We included 59 RCTs with 14,738 participants. Studies assessed comparisons between irrigation and no irrigation, between antibacterial and non-antibacterial irrigation, between different antibiotics, different antiseptics or different non-antibacterial agents, or between different methods of irrigation delivery. No studies compared antiseptic with antibiotic irrigation. Surgical site infectionIrrigation compared with no irrigation (20 studies; 7192 participants): there is no clear difference in risk of SSI between irrigation and no irrigation (RR 0.87, 95% CI 0.68 to 1.11; I2 = 28%; 14 studies, 6106 participants). This would represent an absolute difference of 13 fewer SSIs per 1000 people treated with irrigation compared with no irrigation; the 95% CI spanned from 31 fewer to 10 more SSIs. This was low-certainty evidence downgraded for risk of bias and imprecision.Antibacterial irrigation compared with non-antibacterial irrigation (36 studies, 6163 participants): there may be a lower incidence of SSI in participants treated with antibacterial irrigation compared with non-antibacterial irrigation (RR 0.57, 95% CI 0.44 to 0.75; I2 = 53%; 30 studies, 5141 participants). This would represent an absolute difference of 60 fewer SSIs per 1000 people treated with antibacterial irrigation than with non-antibacterial (95% CI 35 fewer to 78 fewer). This was low-certainty evidence downgraded for risk of bias and suspected publication bias.Comparison of irrigation of two agents of the same class (10 studies; 2118 participants): there may be a higher incidence of SSI in participants treated with povidone iodine compared with superoxidised water (Dermacyn) (RR 2.80, 95% CI 1.05 to 7.47; low-certainty evidence from one study, 190 participants). This would represent an absolute difference of 95 more SSIs per 1000 people treated with povidone iodine than with superoxidised water (95% CI 3 more to 341 more). All other comparisons found low- or very low-certainty evidence of no clear difference between groups.Comparison of two irrigation techniques: two studies compared standard (non-pulsed) methods with pulsatile methods. There may, on average, be fewer SSIs in participants treated with pulsatile methods compared with standard methods (RR 0.34, 95% CI 0.19 to 0.62; I2 = 0%; two studies, 484 participants). This would represent an absolute difference of 109 fewer SSIs occurring per 1000 with pulsatile irrigation compared with standard (95% CI 62 fewer to 134 fewer). This was low-certainty evidence downgraded twice for risks of bias across multiple domains. Wound dehiscenceFew studies reported wound dehiscence. No comparison had evidence for a difference between intervention groups. This included comparisons between irrigation and no irrigation (one study, low-certainty evidence); antibacterial and non-antibacterial irrigation (three studies, very low-certainty evidence) and pulsatile and standard irrigation (one study, low-certainty evidence). Secondary outcomesFew studies reported outcomes such as use of systemic antibiotics and antibiotic resistance and they were poorly and incompletely reported. There was limited reporting of mortality; this may have been partially due to failure to specify zero events in participants at low risk of death. Adverse event reporting was variable and often limited to individual event types. The evidence for the impact of interventions on length of hospital stay was low or moderate certainty; where differences were seen they were too small to be clinically important.

AUTHORS' CONCLUSIONS

The evidence base for intracavity lavage and wound irrigation is generally of low certainty. Therefore where we identified a possible difference in the incidence of SSI (in comparisons of antibacterial and non-antibacterial interventions, and pulsatile versus standard methods) these should be considered in the context of uncertainty, particularly given the possibility of publication bias for the comparison of antibacterial and non-antibacterial interventions. Clinicians should also consider whether the evidence is relevant to the surgical populations under consideration, the varying reporting of other prophylactic antibiotics, and concerns about antibiotic resistance.We did not identify any trials that compared an antibiotic with an antiseptic. This gap in the direct evidence base may merit further investigation, potentially using network meta-analysis; to inform the direction of new primary research. Any new trial should be adequately powered to detect a difference in SSIs in eligible participants, should use robust research methodology to reduce the risks of bias and internationally recognised criteria for diagnosis of SSI, and should have adequate duration and follow-up.

Intra-operative wound irrigation to reduce surgical site infections after abdominal surgery: a systematic review and meta-analysis

PURPOSE

Surgical site infection (SSI) remains to be one of the most frequent infectious complications following abdominal surgery. Prophylactic intra-operative wound irrigation (IOWI) before skin closure has been proposed to reduce bacterial wound contamination and the risk of SSI. However, current recommendations on its use are conflicting especially concerning antibiotic and antiseptic solutions because of their potential tissue toxicity and enhancement of bacterial drug resistances.

METHODS

To analyze the existing evidence for the effect of IOWI with topical antibiotics, povidone-iodine (PVP-I) solutions or saline on the incidence of SSI following open abdominal surgery, a systematic review and meta-analysis of randomized controlled trials (RCTs) was carried out according to the recommendations of the Cochrane Collaboration.

RESULTS

Forty-one RCTs reporting primary data of over 9000 patients were analyzed. Meta-analysis on the effect of IOWI with any solution compared to no irrigation revealed a significant benefit in the reduction of SSI rates (OR = 0.54, 95 % confidence Interval (CI) [0.42; 0.69], p < 0.0001). Subgroup analyses showed that this effect was strongest in colorectal surgery and that IOWI with antibiotic solutions had a stronger effect than irrigation with PVP-I or saline. However, all of the included trials were at considerable risk of bias according to the quality assessment.

CONCLUSION

These results suggest that IOWI before skin closure represents a pragmatic and economical approach to reduce postoperative SSI after abdominal surgery and that antibiotic solutions seem to be more effective than PVP-I solutions or simple saline, and it might be worth to re-evaluate their use for specific indications.

The need for culture swabs in laparoscopically treated appendicitis

INTRODUCTION

Appendicitis remains the most common cause of an acute abdomen. Obtaining intra-abdominal cultures is routine surgical practice. There are studies showing no efficacy of such procedures in cases where open appendectomies are performed.

AIM

The goal of this study was to assess the need for obtaining intra-abdominal cultures during laparoscopic appendectomies.

MATERIAL AND METHODS

Between 2007 and 2012, 369 patients were operated on with the diagnosis of histopathologically proven acute appendicitis. Sixty-two percent of them were operated on using laparoscopic techniques. The microbiological assessment was routinely done for the open procedures and in 42% of cases that underwent a laparoscopic operation.

RESULTS

In 57% (134) the swabbing results were negative. Among 43% (102) of the patients with a positive result, Escherichia coli was isolated in 76.5% (78), Proteus mirabilis in 13.7% (14), Pseudomonas aeruginosa in 4.9% (5) and Citrobacter freundii in 4.9% (5). Five cases had bacteria resistant to the antibiotic given preoperatively (that is 4.9% of all positive cultures and 1.4% of all operated patients). However, these cases did not affect the incidence of postoperative complications. Consideration of the postoperative morbidity showed that there was no statistically significant difference between the laparoscopic group with and without intra-operative swabbing (p > 0.05).

CONCLUSIONS

The postoperative patient outcome was more dependent on the pathology of the appendix than on the results of the microbiological assessment at the time of surgery. Hence, routine intra-operative cultures during laparoscopic appendectomies appear to have little value in patient management. Swabbing during laparoscopic procedures should be limited to only selected high-risk groups.

Primary versus delayed wound closure in complicated appendicitis: an international systematic review and meta-analysis

The purpose of this study was to determine, by means of a systematic review, whether the method of wound closure in complicated appendicitis affects the incidence of wound infection. A comprehensive literature search of multiple databases including MEDLINE (1980-2003), was performed, using the Cochrane search strategy, for articles on wound closure and complicated appendicitis. Clinical trials examining the method of wound closure were selected for systematic review and all quasi-randomized and randomized trials underwent meta-analysis. Failure to close the wound as planned in delayed closure (DC) was considered indicative of a wound infection. Purulent drainage requiring wound opening indicated an infection in the wounds closed primarily. Six randomized trials were considered adequate for meta-analysis. None independently showed a statistically significant difference in the risk of developing a wound infection with primary closure (PC). When pooled data were subjected to meta-analysis, PC achieved a statistically significant reduction in the relative risk of treatment failure and did not lead to an increase in wound infections. Primary closure does not increase the risk of developing a wound infection after operation for perforated appendicitis. Given the lack of benefit of DC, and the less traumatic, less painful, and less costly nature of PC; primary closure is a safe and practical treatment option.

New vesicular ampicillin-loaded delivery systems for topical application: characterization, in vitro permeation experiments and antimicrobial activity

In this paper, the experimental conditions for preparing ampicillin-loaded surfactant vesicles (SVs) are described. Our studies are focused on the potential use of a vesicular polymeric dispersion as ampicillin delivery system for topical application. The main components of the formulation are uncharged and charged SVs loaded with ampicillin and dispersed in a gellan solution. The following issues are addressed: the drug encapsulation efficiency (e.e.), the kinetic of drug release from the delivery systems, the antimicrobial activity of vesicle-entrapped ampicillin. The in vitro permeation experiments through a synthetic lipophilic barrier (Silastic) and through porcine skin are carried out to evaluate the potential use as a dermal formulation. The use of both a synthetic and a biological membrane allows to discriminate between the effects related to variations of thermodynamic parameters and those correlated to biological factors. The release rate of ampicillin is increased by encapsulation in neutral and negatively charged SVs and the permeation rate was slowed by dispersion of drug-loaded SVs in gellan solution. Finally, studies of antimicrobial activity on prepared systems evidenced that ampicillin encapsulated in SVs exhibit a higher activity than the free drug.

Topical ampicillin for prophylaxis against wound infection in acute appendicitis

A total of 249 patients, undergoing appendectomy for acute appendicitis, were prospectively randomized into two groups. Group I, comprising 132 patients, received sterile normal saline irrigation to the surgical wound at closure. Alternatively, Group II included 117 patients, who received intraoperative topical ampicillin irrigation of the wound. Both groups were comparable with regard to age, sex, duration of symptoms, and severity of appendicitis. All patients additionally received preoperative systemic gentamicin and Flagyl. Wound infection occurred in 5.3% of Group I compared to only 0.9% of Group II (P<0.05). The reduction in infection rate was significant (P<0.05) in histologically proven appendicitis. We conclude that the addition of intraoperative topical ampicillin to systemic gentamicin and Flagyl augments prophylaxis against wound infection in acute appendicitis.

Laparoscopic versus open appendicectomy: a prospective assessment

A prospective study of 200 consecutive patients with suspected acute appendicitis was performed to compare open and laparoscopic appendicectomy. Formal randomization was precluded by instrument availability. Some 100 patients underwent laparoscopic appendicectomy (conversion to laparotomy was carried out in five) and 100 had conventional surgery. The groups were similar in sex ratio, age, degree of appendiceal inflammation and antibiotic treatment. The mean duration of open appendicectomy was 46 min and of the laparoscopic procedure 51 min (P not significant). Postoperative complications in patients who underwent laparoscopic appendicectomy included: intra-abdominal abscess (two patients), wound infection (one), early bowel obstruction (four; all resolved with medical treatment) and umbilical haematoma (two). There were no reoperations in the immediate or late postoperative period. Complications after open operation were: wound infection (seven patients) (P < 0.05), early bowel obstruction (five; three resolved with medical treatment, two required surgery) and haematoma of the surgical wound (one). The mean hospital stay was 4.8 days for laparoscopic appendicectomy and 6.0 days for the open operation (P < 0.05). There were no deaths.

[The value of clinical, laboratory and sonographic findings in acute appendicitis--effect of surgical experience and bacteriologic diagnosis on the rate of wound healing disorders]

A total of 361 patients were admitted to the Department of Surgery of the University of Heidelberg between January 1989 and April 1990 for acute appendicitis. Neither the physical examination nor laboratory results were unequivocally diagnostic in a third of the patients. The ultrasonographic visualization of the inflamed appendix could confirm the diagnosis in 50% of the clinically doubtful cases (predictive value: 84%). Further diagnostic procedures were rarely necessary. The perforation rate was independent of the duration of the preoperative hospitalization due to the rapid surgical treatment. Contrary to previous reports, the likelihood of an intraoperatively innocent appendix increased with delayed surgery. Wound infection rates were similar after appendectomies by surgeons in training and by fully qualified surgeons although perforated appendices were typically removed by the latter ones. Antibiotic therapy was usually administered for severely inflamed appendices depending on the intraoperative findings and for perforated appendices and reduced the rate of wound infections if more than two bacteria had been cultured from a routine intraoperative swab. The documentation used in Baden-Württemberg for quality control should include the result of an intraoperative appendiceal swab.

Primary closure of contaminated wounds in perforated appendicitis

We studied the clinical course of 506 children consecutively admitted with appendicitis at The Hospital for Sick Children from 1985 to 1989. One hundred eighty-one children (35%), ranging in age from 1 to 17 years, presented with perforation verified by histological examination. Ninety-six of them (53%) had generalized peritonitis, 47 (26%) had localized peritonitis, and 38 (21%) had abscess formation. Usually, triple antibiotics were begun preoperatively if perforation was suspected; otherwise, cefoxitin was started. Triple antibiotics were used postoperatively for 5 to 7 days in almost all children in the perforated group. Neither abdominal nor subcutaneous drainage was routinely used even in cases of intraabdominal abscess. The skin was closed primarily with steri-strips (63%), staples (20%), subcutaneous Dexon (11%), or silk (4%). Postoperative wound infection arose in 20 children (11%). Wound infections were noted from 1 to 14 days postoperatively (mean, 5.9 days). Whereas 9 of these were treated with local therapy only, 11 delayed the child's discharge or necessitated readmission. No patient suffered major complications from wound infection in that there were no cases of necrotizing fasciitis, reoperation for debridement, sepsis, or death. The intraabdominal abscess rate in this group of 181 children was 6% (n = 11). The low rate of infective complications fully justifies the policy of primary closure in contaminated wounds. This policy eliminates the necessity for painful and time-consuming dressing changes, shortens hospitalization, and obviates the trauma of delayed suturing of wounds in children.

Combined use of topical and systemic antibiotics

An animal wound model was used to compare the effectiveness of topical and systemic antibiotics and to examine the validity of using a combined regimen of both routes of antibiotic delivery. Gross infection rates and wound bacterial concentrations were determined after contamination with Staphylococcus aureus or Escherichia coli. Both moderate (10(8) colony-forming units [CFU]) and heavy (10(12) CFU) contamination were studied for each organism. Following moderate contamination, topical and systemic antibiotics were equally effective in reducing both wound bacterial content and infection rate, but there was no benefit from the combined use of both modes of antibiotic delivery. An additive effect of the combined regimen was noted only when the level of wound contamination was heavy.