Oral antibiotic prophylaxis can influence the inflammatory response in aortic aneurysm repair: results of a randomized clinical study

Prevention of infection in aortic or aortoiliac peripheral arterial reconstruction

BACKGROUND

Peripheral arterial disease (PAD) results from the narrowing of arteries. Aortic aneurysms - abnormal dilatations in artery walls - are a related concern. For severe cases, arterial reconstruction surgery is the treatment option. Surgical site infections (SSIs) are a feared and common complication of vascular surgery. These infections have a significant global healthcare impact. Evaluating the effectiveness of preventive measures is essential.

OBJECTIVES

To assess the effects of pharmacological and non-pharmacological interventions, including antimicrobial therapy, antisepsis, and wound management, for the prevention of infection in people undergoing any open or hybrid aortic or aortoiliac peripheral arterial reconstruction.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, and CINAHL databases, and the World Health Organization International Clinical Trials Registry Platform, LILACS, and ClinicalTrials.gov up to 11 November 2024.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) with a parallel (e.g. cluster or individual) or split-body design, and quasi-RCTs, which assessed any intervention to reduce or prevent infection following aortic or aortoiliac procedures for the treatment of aneurysm or PAD. There were no limitations regarding age and sex.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. Two review authors independently extracted the data and assessed the risk of bias of the trials. A third review author resolved disagreements when necessary. We assessed the evidence certainty for key outcomes using GRADE.

MAIN RESULTS

We included 21 RCTs with 4952 participants. Fifteen studies were assessed as having a high risk of bias in at least one domain, and 19 studies had an unclear risk of bias in at least one domain. We analysed 10 different comparisons for eight different outcomes. The comparisons were antibiotic versus placebo or no treatment; short-duration antibiotics (≤ 24 hours) versus long-duration antibiotics (> 24 hours); different types of systemic antibiotics (one versus another); antibiotic-bonded implant versus standard implant; Dacron graft versus stretch polytetrafluoroethylene graft; prophylactic closed suction drainage versus undrained wound; individualised goal-directed therapy (IGDT) versus fluid therapy based on losses, standard haemodynamic parameters and arterial blood gas values (standard care); comprehensive geriatric assessment versus standard preoperative care; percutaneous versus open-access technique; and negative pressure wound therapy (NPWT) versus standard dressing. The primary outcomes were graft infection rate and SSI rate. The secondary outcomes included all-cause mortality, arterial reconstruction failure rate, re-intervention rate, amputation rate, pain resulting from the intervention, and adverse events resulting from the interventions to prevent infection. We did not assess all the outcomes across the different comparisons. The main findings are presented below. Antibiotic versus placebo or no treatment (five studies) Very low-certainty evidence from five included studies suggests that antibiotic prophylaxis reduces SSI (risk ratio (RR) 0.33, 95% confidence interval (CI) 0.15 to 0.71; 5 studies, 583 participants; number needed to treat for an additional beneficial outcome (NNT) 9). With very low- to low-certainty evidence, there was little or no difference between the groups in the other assessed outcomes (graft infection rate, all-cause mortality, re-intervention rate, and amputation rate). We did not quantitatively assess other outcomes in this comparison. Short duration antibiotics (≤ 24 hours) versus long duration antibiotics (> 24 hours) (three studies) Very low-certainty evidence from three included studies suggests that there is little or no difference in graft infection rate (RR 2.74, 95% CI 0.11 to 65.59; 1 study, 88 participants) or SSI rate (RR 3.65, 95% CI 0.59 to 7.71; 1 study, 88 participants) between short- and long-duration antibiotic prophylaxis. We did not quantitatively assess other outcomes in this comparison. Different types of systemic antibiotics (one versus another) (seven studies) We grouped seven studies comparing one antibiotic to another into three subgroups that compared different classes of antibiotics amongst themselves. We found little or no difference between the groups analysed. Graft infection rate: beta-lactams versus cephalosporins (RR 0.36, 95% CI 0.02 to 8.71; 1 study, 88 participants; very low-certainty evidence); glycopeptides versus cephalosporins (RR 5.00, 95% CI 0.24 to 103.05; 1 study, 238 participants; low-certainty evidence); one cephalosporin versus another (RR not estimable, CI not estimable; 1 study; 69 participants; very low-certainty evidence); SSI rate: beta-lactams and cephalosporins (RR 0.27, 95% CI 0.03 to 2.53; 2 studies, 229 participants; very low-certainty evidence); glycopeptides versus cephalosporins (RR 2.17, 95% CI 0.65 to 7.23; 2 studies, 312 participants; very low-certainty evidence); and one cephalosporin versus another (RR 1.26, 95% CI 0.21 to 7.45; 3 studies, 625 participants; very low-certainty evidence). We could extract all-cause mortality data for the glycopeptide versus cephalosporin comparison; there was little or no difference between groups (RR 1.33, 95% CI 0.30 to 5.83; 1 study, 238 participants; low-certainty evidence). We did not quantitatively assess other outcomes in this comparison.

AUTHORS' CONCLUSIONS

Very low-certainty evidence suggests that the use of prophylactic antibiotics may prevent SSIs in aortic or aortoiliac peripheral arterial reconstruction. We found no superiority amongst specific antibiotics or differences in extended antibiotic use (over 24 hours) compared with shorter use (up to 24 hours), with low-certainty evidence. For other interventions, very low- to moderate-certainty evidence showed little or no difference across various outcomes. We advise interpreting these conclusions with caution due to the limited number of events in all groups and comparisons.

Characteristics, Outcomes, and Clinical Indicators of Bloodstream Infections in Neutropenic Patients with Hematological Malignancies: A 7-Year Retrospective Study

Purpose

The aim of this study was to investigate the current epidemiology, its changes during the study years, and inflammatory biomarkers of bacterial bloodstream infections (BSIs) in neutropenic patients with hematological malignancies. We assessed mortality risk factors and multidrug-resistant (MDR) gram-negative BSI predictors.

Patients and Methods

We conducted a retrospective study from January 2015 to December 2021, which included adult neutropenic oncohematological patients with confirmed BSIs. We used univariable and multivariable analyses to analyze the risk factors. Each index's reliability for bacterial BSI diagnosis was assessed using the receiver-operating characteristic curve and area under the curve.

Results

A total of 514 isolates were obtained from the 452 patients. The average mortality was 17.71%. Gram-negative organisms were the predominant causes of BSI. Escherichia coli was the most common microorganism (49.90%). The overall variation trend of the isolation rate of MDR and carbapenem-resistant gram-negative bacteria increased. Multivariate analysis indicated that: 1) neutropenia that lasted for more than 7 days, patients ≥ 60 years of age, septic shock, hospitalization for >20 days, BSI with a carbapenem-resistant strain, and treatment with linezolid or vancomycin in infections lasting less than 30 days were independent mortality risk factors; 2) severe neutropenia exceeding 7 days, unreasonable empirical therapy, and receipt of aminoglycosides or 3rd or 4th generation cephalosporins in infections lasting less than 30 days were independent risk factors of MDR gram-negative bacteria. Procalcitonin, absolute neutrophil count, and white blood cell indicate higher diagnostic accuracy for BSIs. Moreover, bacteria time to detection was better at differentiating Gram-negative and Gram-positive bacterial infections.

Conclusion

We analyzed the risk factors for BSI neutropenic patients with hematological malignancies, the distribution of bacteria, antibiotic resistance, and the changes in clinical parameters. This single-center retrospective study may provide clinicians with novel insights into the diagnosis and treatment of BSI to improve future clinical outcomes.

Diagnostic value and prognostic implications of serum procalcitonin after cardiac surgery: a systematic review of the literature

INTRODUCTION

Systemic inflammatory response syndrome is common after surgery, and it can be difficult to discriminate between infection and inflammation. We performed a review of the literature with the aims of describing the evolution of serum procalcitonin (PCT) levels after uncomplicated cardiac surgery, characterising the role of PCT as a tool in discriminating infection, identifying the relation between PCT, organ failure, and severity of sepsis syndromes, and assessing the possible role of PCT in detection of postoperative complications and mortality.

METHODS

We performed a search on MEDLINE using the keyword 'procalcitonin' crossed with 'cardiac surgery,' 'heart,' 'postoperative,' and 'transplantation.' Our search was limited to human studies published between January 1990 and June 2006.

RESULTS

Uncomplicated cardiac surgery induces a postoperative increase in serum PCT levels. Peak PCT levels are reached within 24 hours postoperatively and return to normal levels within the first week. This increase seems to be dependent on the surgical procedure and on intraoperative events. Although PCT values reported in infected patients are generally higher than in non-infected patients after cardiac surgery, the cutoff point for discriminating infection ranges from 1 to 5 ng/ml, and the dynamics of PCT levels over time may be more important than absolute values. PCT is superior to C-reactive protein in discriminating infections in this setting. PCT levels are higher with increased severity of sepsis and the presence of organ dysfunction/failure and in patients with a poor outcome or in those who develop postoperative complications. PCT levels typically remain unchanged after acute rejection but increase markedly after bacterial and fungal infections. Systemic infections are associated with greater PCT elevation than is local infection. Viral infections are difficult to identify based on PCT measurements.

CONCLUSION

The dynamics of PCT levels, rather than absolute values, could be important in identifying patients with infectious complications after cardiac surgery. PCT is useful in differentiating acute graft rejection after heart and/or lung transplantation from bacterial and fungal infections. Further studies are needed to define cutoff points and to incorporate PCT levels in useful prediction models.

Markers of bacteremia in febrile neutropenic patients with hematological malignancies: procalcitonin and IL-6 are more reliable than C-reactive protein

Since neutropenic patients with hematological malignancies are at high risk of contracting life-threatening infections, specific markers of infection are needed in cases of febrile neutropenia. The study presented here assessed serum concentrations of C-reactive protein (CRP), procalcitonin (PCT) and interleukin-6 (IL-6) in samples obtained from 31 febrile neutropenic patients. A total of 53 episodes were evaluated, and 18 of these were associated with positive blood culture results. Procalcitonin and IL-6 concentrations differed significantly between bacteremic and non-bacteremic episodes. Procalcitonin values were 0.22 ng/ml [interquartile range (IR), 0.15-1.9] for patients with pneumonia without bacteremia, 0.22 ng/ml (IR, 0.16-0.55) for patients with fever of unknown origin, 0.2 ng/ml (IR, 0.13-0.57) for patients with non-microbial fever and 1.8 ng/ml (IR, 0.35-5.3) for patients with bacteremia. The differences between bacteremic and non-bacteremic episodes had a P-value of 0.003 using the Mann-Whitney test. For IL-6 the median values were 301 pg/ml (IR, 152-1,879) for patients with pneumonia without bacteremia, 207 pg/ml (IR, 94-445) for patients with fever of unknown origin, 177 pg/ml (IR, 142-208) for patients with non-microbial fever and 942 pg/ml (IR, 181-2,807) for patients with bacteremia. Using the Mann-Whitney test, the differences between bacteremic and non-bacteremic episodes were P=0.006. No differences were found in CRP concentrations. Cutoff levels to distinguish between bacteremic and non-bacteremic episodes were chosen using receiver operating characteristic curves: 0.62 ng/ml for PCT and 297 pg/ml for IL-6. Negative predictive values were 84% for PCT and 70% for IL-6. The results indicate that PCT and IL-6 are more reliable markers than CRP for predicting bacteremia in patients with febrile neutropenia.