Infectious complications of cardiac surgery: a clinical review

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.

Role of Radiology in Assessment of Postoperative Complications of Heart Transplantation

Heart transplantation is a pivotal treatment of end-stage heart failure, and recent advancements have extended median posttransplant life expectancy. However, despite the progress in surgical techniques and medical treatment, heart transplant patients still face complications such as rejection, infections, and drug toxicity. CT is a reliable tool for detecting most of these complications, whereas MR imaging is particularly adept at identifying pericardial pathologies and signs of rejection. Awareness of these nuances by radiologists, cardiologists, and surgeons is desired to optimize care, reduce morbidities, and enhance survival.

Peri-operative pharmacokinetics of cefazolin prophylaxis during valve replacement surgery

OBJECTIVE

There is little prospective data to guide effective dosing for antibiotic prophylaxis during surgery requiring cardiopulmonary bypass (CPB). We aim to describe the effects of CPB on the population pharmacokinetics (PK) of total and unbound concentrations of cefazolin and to recommend optimised dosing regimens.

METHODS

Patients undergoing CPB for elective cardiac valve replacement were included using convenience sampling. Intravenous cefazolin (2g) was administered pre-incision and re-dosed at 4 hours. Serial blood and urine samples were collected and analysed using validated chromatography. Population PK modelling and Monte-Carlo simulations were performed using Pmetrics® to determine the fractional target attainment (FTA) of achieving unbound concentrations exceeding pre-defined exposures against organisms known to cause surgical site infections for 100% of surgery (100% fT>MIC).

RESULTS

From the 16 included patients, 195 total and 64 unbound concentrations of cefazolin were obtained. A three-compartment linear population PK model best described the data. We observed that cefazolin 2g 4-hourly was insufficient to achieve the FTA of 100% fT>MIC for Staphylococcus aureus and Escherichia coli at serum creatinine concentrations ≤ 50 μmol/L and for Staphylococcus epidermidis at any of our simulated doses and serum creatinine concentrations. A dose of cefazolin 3g 4-hourly demonstrated >93% FTA for S. aureus and E. coli.

CONCLUSIONS

We found that cefazolin 2g 4-hourly was not able to maintain concentrations above the MIC for relevant pathogens in patients with low serum creatinine concentrations undergoing cardiac surgery with CPB. The simulations showed that optimised dosing is more likely with an increased dose and/or dosing frequency.

Early Postoperative Cardiac Complications Following Heart Transplantation:

Cardiovascular disorders remain the leading cause of death around the world. Heart transplantation is considered the only therapeutic choice defined as the gold standard strategy to manage end-stage heart failure. Nevertheless, the remaining postoperative complications compromise both the survival rate and quality of life in heart transplantation recipients. The present study aimed to review the current findings concerning the main early complications after heart transplantation, reliable predictors, diagnostic approaches, novel surgical techniques, and management strategies. The results demonstrated that significant advances in immunosuppressive pharmaceuticals, determining appropriate policies for donor acceptance, pre and post-operative treatment/care, selection of the most compatible donor with the recipient, and the suggestion of novel diagnostic and surgical techniques over the past decade had dropped the mortality and morbidity rates early after transplantation. However,marrhythmia, atrial flutter, atrial fibrillation, deep sternal wound infection along with other sites infections, low cardiac output syndrome, acute graft dysfunction, pericardial effusion, constrictive pericarditis, and acute cellular rejection could be considered as the major early complications following heart transplantations that pivotally require further investigations.

Effect of an E-Prescription Intervention on the Adherence to Surgical Chemoprophylaxis Duration in Cardiac Surgery: A Single Centre Experience

In our hospital, adherence to the guidelines for peri-operative antimicrobial prophylaxis (PAP) is suboptimal, with overly long courses being common. This practice does not offer any incremental benefit, and it only adds to the burden of antimicrobial consumption, promotes the emergence of antimicrobial resistance, and it is associated with adverse events. Our objective was to study the effect of an electronic reminder on the adherence to each element of PAP after cardiac surgery. We conducted a single center, before and after intervention, prospective cohort study from 1 June 2014 to 30 September 2017. The intervention consisted of a reminder of the hospital guidelines when ordering PAP through the hospital information system. The primary outcome was adherence to the suggested duration of PAP, while secondary outcomes included adherence to the other elements of PAP and incidence of surgical site infections (SSI). We have studied 1080 operations (400 pre-intervention and 680 post-intervention). Adherence to the appropriate duration of PAP increased significantly after the intervention [PRE 4.0% (16/399) vs. POST 15.4% (105/680), chi-square p < 0.001]; however, it remained inappropriately low. Factors associated with inappropriate duration of PAP were pre-operative hospitalization for <3 days, and duration of operation >4 h, while there were significant differences between the chief surgeons. Unexpectedly, the rate of SSIs increased significantly during the study (PRE 2.8% (11/400) vs. POST 5.9% (40/680), chi-square p < 0.019). The implemented intervention achieved a relative increase in adherence to the guideline-recommended PAP duration; however, adherence was still unacceptably low and further efforts to improve adherence are needed.

Prolonged cardiopulmonary bypass time as predictive factor for bloodstream infection

Objectives

To evaluate the correlation between patient characteristics, operative variables and the risk of blood stream infection as well as the association of primary blood stream infection and adverse outcomes.

Methods

Clinical records of 6500 adult patients who underwent open heart surgery between February 2008 and October 2020 were analyzed. The microbiological pattern of the primary BSI and its association with adverse events, such as mortality and major cardiovascular events, were evaluated.

Results

Primary bloodstream infection was diagnosed in 1.7% (n = 108) of patients following cardiac surgery with the application of cardiopulmonary bypass. Most isolated bacteria were gram-negative bacillus groups, such as the Enterobacteriaceae family with Serrata marcescens in 26.26%, followed by the Enterococcaceae family with the Enterococcus faecalis in 7.39% and Enterococcus faecium in 9.14% as the most frequently identified bacteria. The postprocedural mortality, stroke rate p < 0.001, the incidence of postoperative new renal failure p < 0.001, and the renal replacement therapy p < 0.001 were significantly higher in the primary BSI group. Aortic cross-clamp time >120 min, OR 2.31 95%CI 1.34 to 3.98, perfusion time >120 min, OR 2.45 95%CI 1.63 to 3.67, and duration of the intervention >300min, OR 2.78 95%CI 1.47 to 5.28, were significantly related to the primary BSI.

Conclusion

The gram-negative bacillus was the most common microorganism identified in BSI after cardiovascular operations using cardiopulmonary bypass. Patients on dialysis prior to cardiac surgery are at higher risk for having BSI. Enteric bacterial translocation after prolonged cardiopulmonary bypass is a possible mechanism of early primary bloodstream infection in these patients. In patients at high risk, prophylactic use of an antibiotic regimen with broader gram-negative bacteria coverage should be considered, especially in those with prolonged cardiopulmonary bypass and intervention time.

Sutureless bioprosthesis for aortic valve replacement: Surgical and clinical outcomes

BACKGROUND

Aortic valve stenosis is the most common adult valve disease in industrialized countries. The aging population and the increase in comorbidities urge the development of safer alternatives to the current surgical treatment. Sutureless bioprosthesis has shown promising results, especially in complex procedures and in patients requiring concomitant surgeries.

OBJECTIVES

Assess the clinical and hemodynamic performance, safety, and durability of the Perceval® prosthetic valve.

METHODS

This single-center retrospective longitudinal cohort study collected data from all adult patients with aortic valve disease who underwent aortic valve replacement with a Perceval® prosthetic valve between February 2015 and October 2020. Of the 196 patients included (mean age 77.20 ± 5.08 years; 45.4% female; mean EuroSCORE II 2.91 ± 2.20%), the majority had aortic stenosis.

RESULTS

Overall mean cross-clamp and cardiopulmonary bypass times were 33.31 ± 14.09 min and 45.55 ± 19.04 min, respectively. Mean intensive care unit and hospital stay were 3.32 ± 3.24 days and 7.70 ± 5.82 days, respectively. Procedural success was 98.99%, as two explants occurred. Four valves were reimplanted due to intraoperative misplacement. Mean transvalvular gradients were 7.82 ± 3.62 mmHg. Pacemaker implantation occurred in 12.8% of patients, new-onset atrial fibrillation in 21.9% and renal replacement support was necessary for 3.1%. Early mortality was 2.0%. We report no structural valve deterioration, strokes, or endocarditis, and one successfully treated valve thrombosis.

CONCLUSIONS

Our study confirms the excellent clinical and hemodynamic performance and safety of a truly sutureless aortic valve, up to a 5-year follow-up. These results were consistent in isolated and concomitant interventions, solidifying this device as a viable option for the treatment of isolated aortic valve disease.

Risk Factors for Post-cardiac Surgery Infections

Background Cardiac surgery infection is a life-threatening complication associated with high morbidity and mortality. One of the main types of these infections, surgical site infections (SSIs), also called postoperative wound infections basically delayed the post-surgical recovery in many patients. These infections rarely happen within 30 days after surgery due to different risk factors. Objectives The purpose of this study is to determine the risk factors that are involved in causing post-cardiac surgical infections. Methods This study was a retrospective study. The data of postoperative cardiac patients was obtained from the Cardiology and Cardiac Surgery Center in King Fahad Armed Force Hospital, Jeddah. Data on the patients were collected from 2016 to 2021. Eligible patients were those of age 18 and greater. These patients were evaluated on basis of the pre and postoperative risk factors and were analyzed for 30 days after discharge and those that developed SSIs were identified. Results Out of the total number of 2366 patients, 151 patients (6.4%) were identified with post-surgery infections out of which 107 (4.5%) had developed superficial wound infections (SSWIs) and 44 (1.9%) had developed deep wound infections (DSWIs). Infection mainly occurs in the male population (n=88, 58.3%). Major risk factors that were the main cause of post-cardiac surgery infections were diabetes (61.5%), hypertension (56.9%), smoking (38.4%), renal failure (27.1%), and re-do operation (25.1%). Conclusion Our study has demonstrated major risk factors that are involved in the occurrence of post-cardiac surgery infections like smoking, diabetes mellitus, sex, more than one operation during a single stay, etc. In the future, the contribution of various other factors involved in the occurrence of surgical site infections and best practices and methods should be studied and implemented to prevent the occurrence of post-cardiac surgery infections. Various simple techniques can still be utilized to prevent these sorts of infections, which will decrease the mortality rate.

Nosocomial Extracardiac Infections After Cardiac Surgery

Purpose of Review

Nosocomial extracardiac infections after cardiac surgery are a major public health issue affecting 3–8.2% of patients within 30–60 days following the intervention.

Recent Findings

Here, we have considered the most important postoperative infective complications that, in order of frequency, are pneumonia, surgical site infection, urinary tract infection, and bloodstream infection. The overall picture that emerges shows that they cause a greater perioperative morbidity and mortality with a longer hospitalization time and excess costs. Preventive interventions and corrective measures, diminishing the burden of nosocomial extracardiac infections, may reduce the global costs. A multidisciplinary team may assure a more appropriate management of nosocomial extracardiac infections leading to a reduction of hospitalization time and mortality rate.

Summary

The main and most current data on epidemiology, prevention, microbiology, diagnosis, and management for each one of the most important postoperative infective complications are reported. The establishment of an antimicrobial stewardship in each hospital seems to be, at the moment, the more valid strategy to counteract the challenging problems.

Peri-Operative Prophylaxis in Patients of Neonatal and Pediatric Age Subjected to Cardiac and Thoracic Surgery: A RAND/UCLA Appropriateness Method Consensus Study

Surgical site infections (SSIs) represent a potential complication of surgical procedures, with a significant impact on mortality, morbidity, and healthcare costs. Patients undergoing cardiac surgery and thoracic surgery are often considered patients at high risk of developing SSIs. This consensus document aims to provide information on the management of peri-operative antibiotic prophylaxis for the pediatric and neonatal population undergoing cardiac and non-cardiac thoracic surgery. The following scenarios were considered: (1) cardiac surgery for the correction of congenital heart disease and/or valve surgery; (2) cardiac catheterization without the placement of prosthetic material; (3) cardiac catheterization with the placement of prosthetic material; (4) implantable cardiac defibrillator or epicardial pacemaker placement; (5) patients undergoing ExtraCorporal Membrane Oxygenation; (6) cardiac tumors and heart transplantation; (7) non-cardiac thoracic surgery with thoracotomy; (8) non-cardiac thoracic surgery using video-assisted thoracoscopy; (9) elective chest drain placement in the pediatric patient; (10) elective chest drain placement in the newborn; (11) thoracic drain placement in the trauma setting. This consensus provides clear and shared indications, representing the most complete and up-to-date collection of practice recommendations in pediatric cardiac and thoracic surgery, in order to guide physicians in the management of the patient, standardizing approaches and avoiding the abuse and misuse of antibiotics.

Evaluation of Postoperative Development of Saphenous Vein Graft Incision Site Infections in Patients Undergoing Isolated Coronary Artery Bypass Graft Surgery: A Single Center Experience

Objective: This study aimed to evaluate surgical site infection patients developing saphenous vein graft incision site infection after isolated coronary artery bypass graft surgery performed in the cardiovascular surgery clinic of our hospital in the last 12 years to reveal the causative microorganisms, risk factors, and clinical characteristics. Material and Methods: A total of 34 surgical site infection patients (23 females, 11 males; mean age 68.0±9.0 years; range 51-86 years) who underwent isolated coronary artery bypass graft surgery in the cardiovascular surgery clinic of our hospital between March 2009 and November 2020 and who postoperatively developed saphenous vein graft incision site infection were included in the study. The patients' demographic data, underlying diseases, and preoperative, intraoperative, and postoperative risk factors were analyzed retrospectively. Results: In all isolated coronary artery bypass graft surgeries performed over a period of about 12 years, the rate of saphenous vein graft incision site surgical site infection was found to be 0.8%. Of these, 23 (67.6%) were evaluated as superficial incisional surgical site infection and 11 (32.4%) as deep incisional surgical site infection. In the patients who developed surgical site infection, the parameters of age, female sex, obesity, diabetes mellitus, smoking, emergency surgery, use of more than 1 saphenous vein graft, prolonged operation, cardiopulmonary bypass, and aortic clamp durations, intraoperative blood transfusion, length of stay in the intensive care unit, use of inotropes, and total length of hospital stay were all found to be significant. The microorganisms in purulent discharge cultures consisted of Gram-negative bacteria in 18 (53%), Gram-positive bacteria in 12 (35.3%), and fungi in 1 (2.9%). No pathogenic microorganism growth was observed in 5 (14.7%) patients. In the patients with surgical site infection, coagulase-negative staphylococci (17.6%) and Escherichia coli (17.6%) were the most frequently isolated agents. Conclusion: Particular attention should be paid to surgical site infection in patients undergoing a cardiovascular surgery intervention. It should be noted that post coronary artery bypass graft surgery surgical site infection can be reduced by determining its risk factors, modifying surgical techniques, and postoperative close monitoring of patients. Follow-up and personal care are crucial after discharge and an empirical treatment approach should be determined when an infection occurs, taking into account that coagulase-negative staphylococci and E. coli were the two leading infectious agents in our hospital.

Effectiveness of chlorhexidine in preventing infections among patients undergoing cardiac surgeries: a meta-analysis and systematic review

Background

Although several meta-analyses reported the impact of chlorhexidine (CHX) use in patients undergoing various types of surgery, no meta-analysis summarized the overall effectiveness of CHX specifically for cardiac surgery. This meta-analysis aimed to examine the impact of CHX on infections after cardiac surgery compared with other cleansers or antiseptics.

Methods

PubMed, Embase, and the Cochrane Library were searched from inception up to October 2020 for potentially eligible studies: (1) population: patients who underwent cardiac surgery; (2) intervention or exposure: any type of CHX use in the treatment or exposed group; (3) outcome: number of patients with infections; (4) comparison: placebo or other antiseptic agents; (5) English. The primary outcome was surgical site infection (SSI).

Results

Fourteen studies were included, with 8235 and 6901 patients in the CHX and control groups. CHX was not protective against SSI (OR = 0.77, 95% CI: 0.57–1.04, P = 0.090). CHX was protective for superficial wound infection (OR = 0.42, 95% CI: 0.26–0.70, P = 0.001), but not with deep wound infection (P = 0.509). CHX was not protective against urinary tract of infection (P = 0.415) but was protective for bloodstream infection (OR = 0.36, 95% CI: 0.16–0.80, P = 0.012), nosocomial infections (OR = 0.55, 95% CI: 0.44–0.69, P < 0.001), and pneumonia (OR = 0.26, 95% CI: 0.11–0.61, P = 0.002).

Conclusions

In patients undergoing cardiac surgery, CHX does not protect against SSI, deep wound infection, and urinary tract infections but might protect against superficial SSI, bloodstream infection, nosocomial infections, and pneumonia.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13756-021-01009-3.

Relationship between Oral Bacterial Count and Postoperative Complications among Patients with Cardiovascular Disease Treated by Surgery: A Retrospective Cohort Study

In this retrospective observational study, we evaluated the relationship between perioperative oral bacterial counts and postoperative complications in cardiovascular disease (CVD) patients. From April 2012 to December 2018, all patients scheduled for surgery received perioperative oral management (POM) by oral specialists at a single center. Tongue dorsum bacterial counts were measured on the pre-hospitalization day, preoperatively, and postoperatively. Background data were collected retrospectively. Among the 470 consecutive patients, the postoperative complication incidence rate was 10.4% (pericardial fluid storage, n = 21; postoperative pneumonia, n = 13; surgical site infection, n = 9; mediastinitis, n = 2; and seroma, postoperative infective endocarditis, lung torsion, and pericardial effusion, n = 1 each). Oral bacterial counts were significantly higher in the pre-hospitalization than in the pre- and postoperative samples (p < 0.05). Sex, cerebrovascular disease, and operation time differed significantly between complications and no-complications groups (p < 0.05). Multivariate analysis with propensity score adjustment showed a significant association between postoperative oral bacterial count and postoperative complications (odds ratio 1.26; 95% confidence interval, 1.00–1.60; p = 0.05). Since the development of cardiovascular complications is a multifactorial process, the present study cannot show that POM reduces complications but indicates POM may prevent complications in CVD patients.

Association of preoperative infections, nasal Staphylococcus aureus colonization and gut microbiota with left ventricular assist device outcomes

AIMS

Infections are common following left ventricular assist device (LVAD) implantation and predict adverse events. Infections are frequent prior to LVAD implantation although their impact on postoperative outcomes remains unknown. Gut and nasal microbial imbalance may predispose to mucosal colonization with pathogens. Herein, we investigated the predictive role of pre-LVAD infections, and explored the association of nasal Staphylococcus aureus (SA) colonization and gut microbiota, on postoperative outcomes.

METHODS AND RESULTS

Overall, 254 LVAD patients were retrospectively categorized based on pre-LVAD infection status: Group 1, bacterial/fungal bloodstream infection (BSI); Group 2, other bacterial/fungal; Group 3, viral; and Group 4, no infection. In a subset of patients, nasal SA colonization (n = 140) and pre-LVAD stool (n = 25) were analysed using 16S rRNA sequencing. A total of 75 (29%) patients had a pre-LVAD infection [Group 1: 22 (29%); Group 2: 41 (55%); Group 3: 12 (16%)]. Pre-LVAD BSIs were independent predictors of 1-year postoperative mortality and infections [Group 1 vs. 4: hazard ratio (HR) 2.70, P = 0.036 vs. HR 1.8, P = 0.046]. In an unadjusted analysis, pre-LVAD infections other than BSIs, INTERMACS profile ≤2, higher serum creatinine, lower serum albumin and nasal SA colonization were also significantly associated with postoperative infections. Patients with early post-LVAD infections exhibited decreased microbial diversity (P < 0.05).

CONCLUSIONS

Pre-LVAD infections are common. BSIs independently predict postoperative mortality and infections. Additional studies are needed to confirm our findings that pre-LVAD SA nasal colonization and gut microbial composition can help stratify patients' risk for infectious complications after LVAD implantation.

Impact of Postoperative Infections on Readmission and Resource Use in Elective Cardiac Surgery

BACKGROUND

Efforts to reduce postoperative infections have garnered national attention, leading to practice guidelines for cardiac surgical perioperative care. The present study characterized the impact of healthcare-acquired infection (HAI) on index hospitalization costs and post-discharge healthcare utilization.

METHODS

Adults undergoing elective coronary artery bypass grafting (CABG) and/or valve operations were identified in the 2016-2018 Nationwide Readmissions Database. Infections were categorized into bloodstream, gastrointestinal, pulmonary, surgical site, or urinary tract infections. Generalized linear or flexible hazard models were used to assess associations between infections and outcomes. Observed-to-expected (O/E) ratios were generated to examine inter-hospital variation in HAI.

RESULTS

Of an estimated 444,165 patients, 8.0% developed HAI. Patients with HAI were older, had a greater burden of chronic diseases, and more commonly underwent CABG/valve or multi-valve operations (all p<0.001). HAI was independently associated with mortality (odds ratio 4.02, 95% CI 3.67-4.40), non-home discharge (3.48, 95% CI 3.21-3.78), and a cost increase of $23,000 (95% CI 20,900-25,200). At 90 days, HAI was associated with greater hazard of readmission (1.29, 95% CI 1.24-1.35). Pulmonary infections had the greatest incremental impact on patient-level ($24,500, 95% CI 23,100-26,00) and annual cohort costs ($121.8 million, 95% CI 102.2-142.9 million). Significant hospital level variation in HAI was evident, with O/E ranging from 0.17 to 4.3 for cases performed in 2018.

CONCLUSIONS

Infections following cardiac surgery remain common and are associated with inferior outcomes and increased resource use. The presence of inter-hospital variation in this contemporary cohort emphasizes the ongoing need for systematic approaches in their prevention and management.

Effect of Acute Stress Glycemic Control and Long-Term Glycemic Control on the Incidence of Post-Operative Infection in Diabetics Undergoing Cardiac Surgery

Objective

Post-operative infection after cardiac surgery causes prolonged hospital stay and increased mortality. In patients with diabetes, peri-operative and pre-operative glycemic control have been associated with increased risk of post-operative infection. Saudi Arabia is the 7th highest country in the world for the prevalence of diabetes. In our surgical population the incidence of diabetes is 77%. We were aware of a high incidence of post-operative infections in our institution. The aim of this work was to assess how peri-operative and pre-operative glycemic control was related to the six-week incidence of post-operative infection.

Method

We retrospectively collected data for 174 adult patients with diabetes undergoing cardiac surgery between January 2017 and June 2019. For group analysis of peri-operative glycemic control, a mean value of ≤10 mmol/l was categorized as optimal control and a mean value of >10 mmol/l as sub-optimal control. The admission glucose value, the maximum glucose value and glycosylated hemoglobin A1c (HbA1c) were separately recorded. Admission HbA1c was used for optimal long-term control group (HbA1c ≤ 7%) and sub-optimal long-term control group (HbA1c > 7%).

Results

Of the 174 patients 60 (34%) developed infection in the six-week post-operative period. No statistically significant difference in infections was seen in the optimal peri-operative control group (n = 24, 14%) compared to sub-optimal peri-operative control group (n = 36, 21%; p = 0.113). However, patients with infection had a significantly higher mean glucose (10.4 mmol/l versus 9.9 mmol/l, p = 0.0316) than no infection.

Grouping according to their HbA1c: well controlled group (41, 24.0%) and poor control group (130, 76.0%) showed no difference in infections. However, patients with lower HbA1c had better glycemic control as measured by: initial glucose (r = 0.52, p=<0.001); mean peri-operative glucose (r = 0.45, p=<0.001); maximum recorded glucose (r = 0.41, p=<0.001).

Conclusion

The majority of our patients presented with sub-optimal long-term glycemic control which we linked to poor stress glycemic control perioperatively. Patients with post-operative infections had higher mean peri-operative blood glucose. With the high incidence of diabetes in Saudi Arabia we have demonstrated the importance of good pre-operative assessment which allows tighter peri-operative glycemic control to reduce post-operative morbidity.

Effects of perioperative oral care on postoperative inflammation following heart valve surgery

OBJECTIVE

Whether oral health care during the perioperative period can lead to a better outcome after heart valve surgery has not been adequately elucidated. We examined the effects of perioperative oral care on postoperative inflammation response in patients who underwent heart valve surgery.

MATERIALS AND METHODS

In this retrospective cohort study, 223 patients scheduled for single valve heart surgery were divided into the oral care, who underwent professional teeth cleaning or scaling within 3 days prior to surgery, and also following surgery at least twice a week (n = 111), and non-oral care (n = 112) groups. After propensity score matching, records of both groups (80:80) were examined after surgery to evaluate inflammation markers (white blood cell count [WBC], neutrophil/white blood cell ratio [NWR], C-reactive protein [CRP] level, body temperature [BT]).

RESULTS

WBC, NWR, CRP level, and BT were increased in both groups the day following surgery. Thereafter, CRP level, WBC, NWR, and BT on various days after surgery in the oral care group showed greater decreases as compared to the non-oral care group.

CONCLUSIONS

Perioperative oral health care can decrease postoperative inflammation in patients undergoing heart valve surgery and may be important to ensure a better outcome in those patients.

Impact of nosocomial infections on patient mortality following cardiac surgery

STUDY OBJECTIVE

To determine the rate of nosocomial infection among patients undergoing cardiac surgery and to identify risk factors and the impact of these infections on patient mortality.

DESIGN

Prospective observational study.

SETTING

Intensive Care Unit (ICU).

PATIENTS

1097 adult patients who underwent cardiac surgery at Hospital Clínico Universitario de Valladolid between January 2011 and January 2016.

INTERVENTIONS

None.

MEASUREMENTS

Preoperative, intraoperative and postoperative medical, surgical and anaesthetic variables.

MAIN RESULTS

A total of 111 patients (10.1%) acquired a nosocomial infection in the postoperative period. Pneumonia was the most frequent (4.2%) nosocomial infection. Three independent risk factors for the development of a nosocomial infection were identified: cardiopulmonary bypass time, kidney failure and emergency surgery. The stay in the ICU was significantly higher in patients who developed a nosocomial infection (16.6 ± 38.8 vs. 4.4 ± 17.8, P < 0.001). The mortality rate of patients who acquired a nosocomial infection was significantly greater (18%) than that of patients who did not acquire a nosocomial infection (5%) (P < 0.001). The 90-day survival was greater in the group of patients without nosocomial infection (log rank 27.55, P < 0.001). The dynamic modelling of 90-day mortality revealed that in the first week, cardiopulmonary bypass time (HR = 1.00, 95% CI 1.00-1.02, P < 0.001) and emergency surgery (HR = 0.12, 95% CI 0.04-0.37, P < 0.001) were the most important risk factors for mortality, while after the first week, nosocomial infection (HR = 6.23, 95% CI 2.49-15.63, P < 0.001) was the main risk factor, followed by cardiopulmonary bypass time (HR = 1.01, 95% CI 1.00-1.01, P = 0.001) and EuroSCORE (HR = 1.03, 95% CI 1.00-1.06, P = 0.008).

CONCLUSIONS

Nosocomial infections after cardiac surgery constitute the main independent risk factor for mortality after the first week of surgery. These data suggest that its prevention following cardiac surgery must be prioritised to improve patient outcomes.

Local prolonged release of antibiotic for prevention of sternal wound infections postcardiac surgery-A novel technology

INTRODUCTION

Sternal wound infection (SWI) is a devastating postcardiac surgical complication. D-PLEX₁₀₀ (D-PLEX) is a localized prolonged release compound applied as a prophylactic at the completion of surgery to prevent SWI. The D-PLEX technology platform is built as a matrix of alternating layers of polymers and lipids, entrapping an antibiotic (doxycycline). The objective of this study was to assess the safety profile and pharmacokinetics of D-PLEX in reducing SWI rates postcardiac surgery.

METHOD

Eighty-one patients were enrolled in a prospective single-blind randomized controlled multicenter study. Sixty patients were treated with both D-PLEX and standard of care (SOC) and 21 with SOC alone. Both groups were followed 6 months for safety endpoints. SWI was assessed at 90 days.

RESULTS

No SWI-related serious adverse events (SAEs) occurred in either group. The mean plasma C_max in patients treated with D-PLEX was about 10 times lower than the value detected following the oral administration of doxycycline hyclate with an equivalent overall dose, and followed by a very low plasma concentration over the next 30 days. There were no sternal infections in the D-PLEX group (0/60) while there was one patient with a sternal infection in the control group (1/21, 4.8%).

CONCLUSION

D-PLEX was found to be safe for use in cardiac surgery patients. By providing localized prophylactic prolonged release of broad-spectrum antibiotics, D-PLEX has the potential to prevent SWI postcardiac surgery and long-term postoperative hospitalization, reducing high-treatment costs, morbidity, and mortality.

Deep sternal wound infection following cardiac surgery: A comparison of the monolateral with the bilateral pectoralis major flaps

Deep sternal wound infections are a serious complication following sternotomy for cardiothoracic surgery. "Conventional" treatment provides debridement and secondary closure or closed catheter irrigation. The combination of the Negative Pressure Therapy with flap coverages is an accepted technique and one or both Pectoralis Major muscles could be chosen. A multistep protocol was adopted. One hundred and sixty seven patients were treated with the combination of Negative Pressure Therapy with the Pectoralis Major muscle flap: 86 monolateral flap and 81 bilateral flap reconstruction. The main complications (hematoma, seroma, dehiscence, and re-infection), the need for re-intervention, mortality rates, Intensive Care Unit, and hospitalisation time were assessed. The mono-pectoralis group had fewer complications and need for revision, with a shorter hospital stay. A statistically significant difference emerged for the hematoma rate (P = .0079). Monolateral flap should to be preferred because with the same coverage effectiveness, it guarantees the saving of controlateral muscle with its functionality and the possibility of its use in case of failure. Furthermore, as the technique is less invasive, it can be reserved for more fragile patients.

Current and emerging pharmacotherapy for the treatment of infections following open-heart surgery

INTRODUCTION

Patients undergoing open-heart surgery may suffer from postoperative complications, including severe infections. Antimicrobials to treat infectious complications in this population should be selected thoughtfully, taking into account three different and fundamental issues: (i) the site of infection; (ii) the suspected or proven causative agent and its susceptibility pattern; and (iii) the risk of suboptimal pharmacokinetic characteristics and potential toxicity of the chosen drug/s.

AREAS COVERED

The present narrative review summarizes the current and future antimicrobial options for the treatment of infections developing after open-heart surgery.

EXPERT OPINION

The pharmacological treatment of infections developing in cardiac surgery patients poses peculiar challenges, including the need for an active empirical therapy for severe events such as bloodstream infections, deep sternal wound infections, or early-onset postoperative prosthetic endocarditis. In addition, the risk for multidrug-resistant pathogens should also be taken into account in endemic areas. A multidisciplinary evaluation on a patient-by-patient basis, deeply involving infectious diseases specialists and cardiothoracic surgeons, remains essential for appropriately balancing both short-term and long-term risks and benefits of any possible surgical reintervention in combination with adequate pharmacotherapy.

Cefuroxime plasma and tissue concentrations in patients undergoing elective cardiac surgery: Continuous vs bolus application. A pilot study

Aims

Surgical site infections contribute to morbidity and mortality after surgery. The authors hypothesized that higher antibiotic tissue concentrations can be reached for a prolonged time span by continuous administration of prophylactic cefuroxime compared to bolus administration.

Methods

Twelve patients undergoing elective cardiac surgery were investigated. Group A received 1.5 g cefuroxime as bolus infusions before surgery, and 12 and 24 hours thereafter. In group B, a continuous infusion of 3.0 g cefuroxime was started after a bolus of 1.5 g. Cefuroxim levels were determined in blood and tissue (microdialysis). T‐test, Wilcoxon signed rank test and χ² test were used for statistical analysis.

Results

The area under the curve (AUC) of plasma cefuroxime concentrations was greater in group B (399 [333–518]) as compared to group A (257 [177–297] h mg L⁻¹, [median and interquartile range], P = .026). Furthermore, a significantly longer percentage of time > minimal inhibitory concentrations of 2 mg L⁻¹ (100% vs 50%), 4 mg L⁻¹ (100% vs 42%), 8 mg L⁻¹ (100% vs 17%) and 16 mg L⁻¹ (83% vs 8%) was found for free plasma cefuroxime in group B. In group B, area under the curve in subcutaneous tissue (78 [61–113] h mg L⁻¹) and median peak concentration (33 [26–38] mg L⁻¹) were markedly higher compared to group A (P = 0.041 and P = .026, respectively).

Conclusions

Higher cefuroxime concentrations were measured in plasma and subcutaneously over a prolonged period of time when cefuroxime was administered continuously. The clinical implication of this finding still has to be elucidated.

Cardiopulmonary Bypass Time Predicts Early Postoperative Enterobacteriaceae Bloodstream Infection

BACKGROUND

A bloodstream infection in patients undergoing cardiovascular operations is crucial because it can result in significantly worse outcomes. However, microbiological patterns have rarely been investigated in these patients.

METHODS

We retrospectively reviewed the data of 1,041 adult patients who underwent cardiovascular operations using cardiopulmonary bypass from January 2013 to December 2017 at the National Cheng Kung University Hospital, Tainan, Taiwan. The microbiological pattern and associated variables were analyzed in patients with early postoperative primary bloodstream infection.

RESULTS

Primary bloodstream infection developed in 28 patients (2.7%) within 7 days after cardiovascular operations using cardiopulmonary bypass. In patients with early primary bloodstream infection, 36 microorganisms were isolated, and a gram-negative bacillus was identified to be the predominant pathogen (28 of 36 [77.8%]). The most common microorganisms comprised the Enterobacter (n = 8) and Acinetobacter (n = 7) species, and 16 of the 28 gram-negative bacilli belonged to the Enterobacteriaceae family. Compared with those without postoperative bloodstream infection, patients with Enterobacteriaceae family-related early postoperative bloodstream infections had a significantly longer cardiopulmonary bypass time and also worse early and late survival rates.

CONCLUSIONS

Most patients with early primary bloodstream infection after cardiovascular operations using cardiopulmonary bypass were infected with gram-negative bacilli, and the Enterobacteriaceae family was the most common microorganism observed. Endogenous bacterial translocation after prolonged cardiopulmonary bypass is a possible mechanism of Enterobacteriaceae family-related early primary bloodstream infection in these patients. Prophylactic use of an antibiotic regimen with broader gram-negative bacteria coverage in cardiovascular surgical patients with prolonged cardiopulmonary bypass should be considered.

Vitamin C to Improve Organ Dysfunction in Cardiac Surgery Patients-Review and Pragmatic Approach

The pleiotropic biochemical and antioxidant functions of vitamin C have sparked recent interest in its application in intensive care. Vitamin C protects important organ systems (cardiovascular, neurologic and renal systems) during inflammation and oxidative stress. It also influences coagulation and inflammation; its application might prevent organ damage. The current evidence of vitamin C's effect on pathophysiological reactions during various acute stress events (such as sepsis, shock, trauma, burn and ischemia-reperfusion injury) questions whether the application of vitamin C might be especially beneficial for cardiac surgery patients who are routinely exposed to ischemia/reperfusion and subsequent inflammation, systematically affecting different organ systems. This review covers current knowledge about the role of vitamin C in cardiac surgery patients with focus on its influence on organ dysfunctions. The relationships between vitamin C and clinical health outcomes are reviewed with special emphasis on its application in cardiac surgery. Additionally, this review pragmatically discusses evidence on the administration of vitamin C in every day clinical practice, tackling the issues of safety, monitoring, dosage, and appropriate application strategy.

Sternal wound infections following cardiac surgery and their management: a single-centre study from the years 2016-2017

Introduction

Despite improvements in surgical management, sternal wound infection (SWI) following cardiac surgery remains a significant complication.

Aim

To evaluate pathogens involved in SWI following median sternotomy.

Material and methods

We enrolled 164 patients who experienced prolonged sternal wound healing following open-heart surgery. The inclusion criteria were as follows: prolonged sternal wound healing following cardiac surgery via median sternotomy and complete results of microbiological culture obtained from the sternal swab. The exclusion criteria were as follows: partial sternotomy, patients with mechanical sternum dehiscence and incomplete clinical data. Swabs provided information on the type of microorganism present in the wound and the susceptibility of the microorganism to specific antibiotics.

Results

One hundred and fourteen (69.5%) patients aged 68 (interquartile range: 60–76) years developed SWI with positive culture. The in-hospital mortality rate was 21.0% in this group. The most common pathogens included Staphylococcus epidermidis (26.6%), Enterococcus faecium (12.2%), Staphylococcus aureus (11.4%), Klebsiella pneumoniae (8.4%), and Pseudomonas aeruginosa (6.8%). In most of the cases the isolated Staphylococcus epidermidis was methicillin-resistant (n = 57, 43.5%). Enterococcus faecium was vancomycin-resistant in 11 (8.3%) cases and high-level aminoglycoside resistant (HLAR) in 13 (9.9%) cases. Klebsiella pneumoniae had the extended-spectrum β-lactamase (ESBL) mechanism in 14 (10.6%) cases. Among 114 culture-positive patients, 48 (42.1%) had polymicrobial infection of the sternal wound.

Conclusions

Microorganisms associated with SWI in our study were mainly commensals, with the most common pathogen being Staphylococcus epidermidis.

Dosing antibiotic prophylaxis during cardiopulmonary bypass-a higher level of complexity? A structured review

In highly invasive procedures such as open heart surgery, the risk of post-operative infection is particularly high due to exposure of the surgical field to multiple foreign devices. Adequate antibiotic prophylaxis is an essential intervention to minimise post-operative morbidity and mortality. However, there is a lack of clear understanding on the adequacy of traditional prophylactic dosing regimens, which are rarely supported by data. The aim of this structured review is to describe the relevant pharmacokinetic/pharmacodynamic (PK/PD) considerations for optimal antibiotic prophylaxis for major cardiac surgery including cardiopulmonary bypass (CPB). A structured review of the relevant published literature was performed and 45 relevant studies describing antibiotic pharmacokinetics in patients receiving extracorporeal CPB as part of major cardiac surgery were identified. Some of the studies suggested marked PK alterations in the peri-operative period with increases in volume of distribution (V_d) by up to 58% and altered drug clearances of up to 20%. Mechanisms proposed as causing the PK changes included haemodilution, hypothermia, retention of the antibiotic within the extracorporeal circuit, altered physiology related to a systemic inflammatory response, and maldistribution of blood flow. Of note, some studies reported no or minimal impact of the CPB procedure on antibiotic pharmacokinetics. Given the inconsistent data, ongoing research should focus on clarifying the influence of CPB procedure and related clinical covariates on the pharmacokinetics of different antibiotics during cardiac surgery. Traditional prophylactic dosing regimens may need to be re-assessed to ensure sufficient drug exposures that will minimise the risk of surgical site infections.

A meta-analysis of platelet gel for prevention of sternal wound infections following cardiac surgery

Deep sternal wound infection and bleeding are devastating complications following cardiac surgery, which may be reduced by topical application of autologous platelet gel. Systematic review identified seven comparative studies involving 4,692 patients. Meta-analysis showed significant reductions in all sternal wound infections (odds ratio 3.48 [1.08-11.23], p=0.04) and mediastinitis (odds ratio 2.69 [1.20-6.06], p=0.02) but not bleeding. No adverse events relating to the use of topical platelet-rich plasma were reported. The use of autologous platelet gel in cardiac surgery appears to provide significant reductions in serious sternal wound infections, and its use is unlikely to be associated with significant risk.

Risk factors for the development of postoperative pneumonia after cardiac surgery

OBJECTIVE

Identify risk factors that determine pneumonia development in patients who have undergone cardiac surgery.

METHODS

Prospective study of a single cohort in a postoperative intensive care unit at a tertiary care center, encompassing all patients undergoing cardiac surgery from January to July 2014.

RESULTS

31 postoperative pneumonia cases were enrolled out of 211 patients (14.6%). The following independent risk factors were identified: hypertension (OR: 3.94, p=0.01), chronic renal failure (OR: 13.67, p=0.02), reintubation (OR: 22.29, p=0.001) and extubation after 6h (OR: 15.81, p=0.005).

CONCLUSIONS

Main determinants for pneumonia after surgery were hypertension, chronic renal failure, extubation after 6h and reintubation.

Nutritional status and nosocomial infections among adult elective surgery patients in a Mexican tertiary care hospital

Background

Controversy exists as to whether obesity constitutes a risk-factor or a protective-factor for the development of nosocomial Infection (NI). According to the obesity-paradox, there is evidence that moderate obesity is a protective-factor. In Mexico few studies have focused on the nutritional status (NS) distribution in the hospital setting.

Objectives

The aim of this study was to estimate the distribution of NS and the prevalence of nosocomial infection NI among adult elective surgery (ES) patients and to compare the clinical and anthropometric characteristics and length of stays (LOS) between obese and non-obese patients and between patients with and without NI.

Methods

We conducted a cross-sectional study with a sample (n = 82) adult ES patients (21–59 years old) who were recruited from a tertiary-care hospital. The prevalences of each NS category and NI were estimated, the assessments were compared between groups (Mann-Whitney, Chi-squared or the Fisher's-exact-test), and the association between preoperative risk-factors and NI was evaluated using odds ratios.

Results

The distribution of subjects by NS category was: underweight (3.66%), normal-weight (28.05%), overweight (35.36%), and obese (32.93%). The prevalence of NI was 14.63%. The LOS was longer (p<0.001) for the patients who developed NI. The percentages of NI were: 33.3% in underweight, 18.52% in obese, 17.39% in normal-weight, and 6.90% in overweight patients.

Conclusion

The prevalence of overweight and obesity in adult ES patients is high. The highest prevalence of NI occurred in the underweight and obese patients. The presence of NI considerably increased the LOS, resulting in higher medical care costs.

Impact of hospital infections on patients outcomes undergoing cardiac surgery at Santa Casa de Misericórdia de Marília

Objective

this study aimed to determine the incidence of nosocomial infections, the risk factors and the impact of these infections on mortality among patients undergoing to cardiac surgery.

Methods

Retrospective cohort study of 2060 consecutive patients from 2006 to 2012 at the Santa Casa de Misericórdia de Marília.

Results

351 nosocomial infections were diagnosed (17%), 227 non-surgical infections and 124 surgical wound infections. Major infections were mediastinitis (2.0%), urinary tract infection (2.8%), pneumonia (2.3%), and bloodstream infection (1.7%). The in-hospital mortality was 6.4%. Independent variables associated with non-surgical infections were age > 60 years (OR 1.59, 95% CI 1.09 to 2.31), ICU stay > 2 days (OR 5, 49, 95% CI 2.98 to 10, 09), mechanical ventilation > 2 days (OR11, 93, 95% CI 6.1 to 23.08), use of urinary catheter > 3 days (OR 4.85 95% CI 2.95 -7.99). Non-surgical nosocomial infections were more frequent in patients with surgical wound infection (32.3% versus 7.2%, OR 6.1, 95% CI 4.03 to 9.24). Independent variables associated with mortality were age greater than 60 years (OR 2.0; 95% CI 1.4 to3.0), use of vasoactive drugs (OR 3.4, 95% CI 1.9 to 6, 0), insulin use (OR 1.8; 95% CI 1.2 to 2.8), surgical reintervention (OR 4.4; 95% CI 2.1 to 9.0) pneumonia (OR 4.3; 95% CI 2.1 to 8.9) and bloodstream infection (OR = 4.7, 95% CI 2.0 to 11.2).

Conclusion

Non-surgical hospital infections are common in patients undergoing cardiac surgery; they increase the chance of surgical wound infection and mortality.

Prevention of infectious complications after heart surgery in children: procalcitonin-guided strategy

Introduction

Infectious complications remain a significant problem of modern cardiac surgery. New prevention strategies, based on the pathogenesis of such complications occurring after cardiopulmonary bypass (CPB) procedures, should be evaluated.

Aim of the study

To evaluate the effectiveness of a procalcitonin (PCT)-guided strategy involving the use of IgM-enriched intravenous immunoglobulins (IVIGs) in children with congenital heart disease with systemic inflammation during the early postoperative period.

Material and methods

Sixty consecutive patients aged 25 (21-30) months who underwent cardiac surgery with CPB and had blood PCT levels > 2 ng/mL on the 1^st postoperative day were enrolled in this single-center prospective randomized clinical trial. The patients were randomized into two groups, comparable in terms of the severity of their initial condition, age, and CPB time. IgM-enriched IVIGs (Pentaglobin, Biotest Pharma GmbH, Germany) were administered during the first 3 postoperative days (5 mL/kg each day) in the study group (n = 30) in addition to the standard treatment, which was also provided to the control group (n = 30). The data are presented as medians with 25-75^th percentiles; they were compared by the Mann-Whitney U-test, and p values of < 0.05 were considered as statistically significant.

Results

Postoperatively, 1/30 (3.3%) patients in the study group and 8/30 (26.7%) in the control group suffered from infectious complications (study group: urinary tract infection [UTI] – 1; control group: pneumonia – 4, pneumonia and sepsis – 2, peritonitis with multiorgan failure – 1, UTI – 1), p = 0.03. The length of hospital stay in the study group was shorter than in the control group: 19 (16-23) days vs. 24 (19-29) days, p = 0.002, as was the length of intensive care unit (ICU) stay: 3 (2-4) days vs. 4 (2-8) days, p = 0.03.

Conclusions

High PCT levels on the 1st postoperative day are associated with an increased risk of infectious complications after cardiac surgery. Early administration of IgM-enriched IVIGs can prevent the development of infectious complications.