Continuous Intraoperative Cefazolin Infusion May Reduce Surgical Site Infections During Cardiac Surgical Procedures: A Propensity-Matched Analysis

Association of adherence to individual components of Society of Thoracic Surgeons cardiac surgery antibiotic guidelines and postoperative infections

OBJECTIVES

The study objectives were to measure the association among the 4 components of Society of Thoracic Surgeons antibiotic guidelines and postoperative complications in a cohort of patients undergoing valve or coronary artery bypass grafting requiring cardiopulmonary bypass.

METHODS

In this retrospective observational study, adult patients undergoing coronary revascularization or valvular surgery who received a Surgical Care Improvement Project-compliant antibiotic from January 1, 2016, to April 1, 2021, at a single, tertiary care hospital were included. The primary exposures were adherence to the 4 individual components of Society of Thoracic Surgeons antibiotic best practice guidelines. The association of each component and a combined metric was tested in its association with the primary outcome of postoperative infection as determined by Society of Thoracic Surgeons data abstractors, controlling for several known confounders.

RESULTS

Of the 2829 included patients, 1084 (38.3%) received care that was nonadherent to at least 1 aspect of Society of Thoracic Surgeons antibiotic guidelines. The incidence of nonadherence to the 4 individual components was 223 (7.9%) for timing of first dose, 639 (22.6%) for antibiotic choice, 164 (5.8%) for weight-based dose adjustment, and 192 (6.8%) for intraoperative redosing. In adjusted analyses, failure to adhere to first dose timing guidelines was directly associated with Society of Thoracic Surgeons-adjudicated postoperative infection (odds ratio, 1.9; 95% confidence interval, 1.1-3.3; P = .02). Failure of weight-adjusted dosing was associated with both postoperative sepsis (odds ratio, 6.9; 95% confidence interval, 2.5-8.5; P < .01) and 30-day mortality (odds ratio, 4.3; 95% confidence interval, 1.7-11.4; P < .01). No other significant associations among the 4 Society of Thoracic Surgeons metrics individually or as a combination were observed with postoperative infection, sepsis, or 30-day mortality.

CONCLUSIONS

Nonadherence to Society of Thoracic Surgeons antibiotic best practices is common. Failure of antibiotic timing and weight-adjusted dosing is associated with odds of postoperative infection, sepsis, and mortality after cardiac surgery.

Enhanced Recovery After Surgery Cardiac Society turnkey order set for surgical-site infection prevention: Proceedings from the American Association for Thoracic Surgery ERAS Conclave 2023

OBJECTIVES

Surgical-site infections (SSIs) after cardiac surgery increase morbidity and mortality, consume health care resources, impair recovery, and diminish patients' quality of life. Numerous guidelines and expert consensus documents have been published to address the prevention and management of SSIs. Our objective is to integrate these documents into an order set that will facilitate the adoption and implementation of evidence-based best practices for preventing and managing SSIs after cardiac surgery.

METHODS

Subject matter experts were consulted to translate existing guidelines and literature into a sample turnkey order set for SSI reduction. Orders derived from consistent class I, IIA, or equivalent recommendations across referenced guidelines and consensus manuscripts appear in the turnkey order set in bold type. Selected orders that were inconsistent class I or IIA, class IIB or otherwise supported by published evidence, were also included in italicized type.

RESULTS

Preventative care begins with the preoperative identification of both modifiable and nonmodifiable SSI risks by health care providers. Assessment tools can be used to assist in identifying patients at a high risk of SSI. Preoperative recommendations include screening for and treating Staphylococcus aureus nasal carriage. Intraoperatively, tailored prophylactic intravenous antibiotics and maintaining blood glucose levels below 180 mg/dL are essential elements. Postoperative care includes maintaining normothermia, glucose control and patient engagement.

CONCLUSIONS

Despite the well-documented advantages of a multidisciplinary care pathway for SSI in cardiac surgery, there are inconsistencies in its adoption and implementation. This article provides an order set that incorporates recommendations from existing guidelines to prevent SSI in the cardiac surgical population.

Effective Antimicrobial Prophylaxis in Surgery: The Relevance and Role of Pharmacokinetics-Pharmacodynamics

Appropriate surgical antimicrobial prophylaxis (SAP) is an important measure in preventing surgical site infections (SSIs). Although antimicrobial pharmacokinetics-pharmacodynamics (PKPD) is integral to optimizing antibiotic dosing for the treatment of infections, there is less research on preventing infections postsurgery. Whereas clinical studies of SAP dose, preincision timing, and redosing are informative, it is difficult to isolate their effect on SSI outcomes. Antimicrobial PKPD aims to explain the complex relationship between antibiotic exposure during surgery and the subsequent development of SSI. It accounts for the many factors that influence the PKs and antibiotic concentrations in patients and considers the susceptibilities of bacteria most likely to contaminate the surgical site. This narrative review examines the relevance and role of PKPD in providing effective SAP. The dose-response relationship i.e., association between lower dose and SSI in cefazolin prophylaxis is discussed. A comprehensive review of the evidence for an antibiotic concentration-response (SSI) relationship in SAP is also presented. Finally, PKPD considerations for improving SAP are explored with a focus on cefazolin prophylaxis in adults and outstanding questions regarding its dose, preincision timing, and redosing during surgery.

Perioperative cefazolin prophylaxis in paediatric cardiac surgery: a prospective, cohort study

BACKGROUND

This study's objective was to determine the effect of age, prolonged bypass, and hypothermia on serum cefazolin concentrations in children undergoing cardiac surgery.

METHODS

A prospective, single-centre, observational study was conducted. Children undergoing cardiac surgery were examined. Participants received cefazolin intravenously approximately 1 hour before skin incision, 3 hourly intraoperatively and 8 hourly postoperatively. Blood samples were collected at 6-8 timepoints intraoperatively and 6-time points in the first 24 hours postoperatively. Target unbound serum cefazolin concentrations were of 2 mg/L.

RESULTS

Sixty-eight patients were enrolled in the study, and 64 included in the analysis. All maintained concentrations ≥ 2 mg/L throughout the operation. Nineteen patients (30%) did not maintain concentrations ≥ 2 mg/L in the first 24 hours following surgery. Older, larger children (p < 0.0001) were significantly less likely to achieve target unbound serum cefazolin concentrations.

CONCLUSIONS

Intraoperative cefazolin concentrations reached the target concentration in all paediatric cardiac surgical cases. Postoperative cefazolin dosing appears insufficient to achieve minimum inhibitory concentrations in many patients.

Surgical Site Infections in Cardiac Surgery

Surgical site infection (SSI) can be a significant complication of cardiac surgery, delaying recovery and acting as a barrier to enhanced recovery after cardiac surgery. Several risk factors predisposing patients to SSI including smoking, excessive alcohol intake, hyperglycemia, hypoalbuminemia, hypo- or hyperthermia, and Staphylococcus aureus colonization are discussed. Various measures can be taken to abolish these factors and minimize the risk of SSI. Glycemic control should be optimized preoperatively, and hyperglycemia should be avoided perioperatively with the use of intravenous insulin infusions. All patients should receive topical intranasal Staphylococcus aureus decolonization and intravenous cephalosporin if not penicillin allergic.

The Year in Review: Anesthesia for Congenital Heart Disease 2018

This review article surveys the published literature from January 2018 to March 2019. Three themes were identified and articles were selected based on their originality and interest to anesthesiologists caring for patients with congenital heart disease.

Pharmacodynamic model for β-lactam regimens used in surgical prophylaxis: model-based evaluation of standard dosing regimens

Background Continual evolution of resistance among bacteria against methods of surgical prophylaxis may make currently used beta-lactam regimens inadequate. Objective To re-evaluate beta-lactam regimens in surgical prophylaxis. Setting A pharmacodynamic Monte Carlo simulation (MCS) model based on a number of patients in China. Methods Pharmacodynamic profiling using Monte Carlo simulation up to 4 hours postinfusion was conducted for standard-dose, short-term (0.5 h) and prolonged (2 to 4 h) infusions of ampicillin, cefazolin, cefotaxime, cefoxitin, cefuroxime, ertapenem, and piperacillin/tazobactam in adult patients with normal renal function. Microbiological data were incorporated. Cumulative fraction of response (CFR) was determined for each regimen against populations of S. aureus, coagulase-negative staphylococci and E. coli. The optimal CFR was defined as ≥ 90% response. Main Outcome Measure Cumulative fractions of response of pharmacodynamic target attainment. Results During the first 2 hours postinfusion, piperacillin/tazobactam 3.375 g exhibited consistently optimal cumulative fractions against S. aureus, CoNS and E. coli. Ampicillin 2 g (2 h) also displayed optimal CFRs for S. aureus and E. coli but not for coagulase-negative staphylococci. Cefoxitin 2 g didnot achieve any optimal CFRs, even via 2-h prolonged infusion (maximum 72.8% CFR for S. aureus and 64.5% CFR for E. coli). Cefazolin 2 g (4 h) and cefuroxime 1.5 g (4 h) provided desired CFRs across 4 h postinfusion for S. aureus but provided poor CFRs for coagulase-negative staphylococci and E. coli. Only ertapenem 1 g for E. coli and S. aureus and cefotaxime 1 g for E. coli consistently yielded ≥ 90% CFRs for 4 hour postinfusion. Conclusions Certain dosing regimens may warrant adjustment for improved prevention efficiency and enhanced empirical antibiotic regimens for surgical prophylaxis.

Pharmacokinetics of cefuroxime in infants and neonates undergoing cardiac surgery

AIMS

Very little data exist regarding the effect of cardiopulmonary bypass (CPB) on cefuroxime (CXM) pharmacokinetics in children less than one year of age.

METHODS

50 mg kg^-1 CXM i.v. after induction were followed by 75 mg kg^-1 into the CPB circuit. In 42 patients undergoing cardiac surgery, 15-20 samples were obtained between 5 and 360 min after the first dose. Total CXM concentrations were measured by high-performance liquid chromatography and a pharmacokinetic/pharmacodynamic (PK/PD) modelling was performed.

RESULTS

Using a fixed protein binding of 15.6% for CXM, peak plasma concentrations of unbound CXM were 229 ± 52 μg ml^-1 after the first bolus and 341 ± 86 μg ml^-1 on CPB. Nadir concentrations before CPB were 69 ± 20 μg ml^-1 and six hours later decreased to 41 ± 19 μg ml^-1 with and 24 ± 14 μg ml^-1 without CPB. A two-compartment model was fitted with the main covariates body weight, CPB and postmenstrual age (PMA). PK parameters were as follows: systemic clearance, 5.15 [95% CI 4.5-5.8] l h^-1 ; central volume of distribution, 11.25 [9.41-13.09] l; intercompartmental clearance, 18.19 [14.79-21.58] l h^-1 ; and peripheral volume, 17.07 [15.7-18.5] L. ƒT > MIC of 32 μg ml^-1 for an 8-h time period was between 70 and 100% (2.5-10 kg BW). According to our simulation, 25 mg ml^-1 CXM as a primary bolus and into the prime plus a 5 mg kg^-1  h^-1 infusion maintain CXM concentrations continuously above 32 μg ml^-1 .

CONCLUSIONS

The routine dosing regimen provided was sufficient for prophylaxis, but continuous dosing can provide a higher percentage of ƒT > MIC.

Impact of Intraoperative Continuous-Infusion Versus Intermittent Dosing of Cefazolin Therapy on the Incidence of Surgical Site Infections After Coronary Artery Bypass Grafting

STUDY OBJECTIVES

To determine whether intraoperative continuous-infusion (CI) cefazolin reduces the incidence of surgical site infections (SSIs) compared with intermittent (INT) cefazolin dosing in patients undergoing coronary artery bypass grafting (CABG) on cardiopulmonary bypass (CPB); safety end points and protocol adherence comparing the two dosing strategies were also explored.

DESIGN

Retrospective quasi-experimental (pre-post intervention) cohort study.

SETTING

Large academic medical center.

PATIENTS

A total of 516 adults who underwent CABG on CPB and received cefazolin intraoperatively between June 1, 2013, and December 31, 2014, were included. The INT cohort included 284 patients who underwent CABG from June 2013 to February 2014. The CI cohort included 232 patients who underwent CABG from April to December 2014, after an intraoperative CI cefazolin protocol for cardiac surgery patients undergoing CPB was adopted in March 2014.

MEASUREMENTS AND MAIN RESULTS

The primary end point was incidence of SSIs, and safety end points of renal dysfunction and seizures were evaluated. Multivariable logistic regression analysis was used to determine the impact on SSIs when controlling for other risk factors. A subgroup analysis for this study included 2 months within each time period to evaluate protocol adherence. The overall incidence of SSIs was decreased in patients receiving CI cefazolin, although this did not reach statistical significance (4.6% in the INT cohort vs 1.7% in the CI cohort, p=0.116). Superficial SSIs were significantly reduced in the CI cohort (2.8% in the INT cohort vs 0.4% in the CI cohort, p=0.039). In the regression analysis, CI cefazolin decreased the odds of SSI by 66%, although it did not reach statistical significance (p=0.077). Safety end points were not significantly different between groups. Overall protocol adherence did not differ significantly between the cohorts: 77% in the INT cohort and 67% in the CI cohort (p=0.212).

CONCLUSION

CI cefazolin significantly decreased the incidence of superficial SSIs compared with INT cefazolin in patients undergoing CABG on CPB, without increasing the risk for adverse effects. As this study was underpowered to detect a significant difference in overall SSIs, larger, randomized studies are required to validate the superiority of CI cefazolin.