Surgical site infection after colorectal surgery according to the main anesthetic agent: a retrospective comparison between volatile anesthetics and propofol

[Influence of anesthesia on surgical site infections]

Surgical site infections (SSI) are the most frequent cause of impaired perioperative wound healing, lead to increased postoperative morbidity, mortality and length of hospital stay and are therefore a relevant perioperative complication. In addition to numerous measures taken by the surgical departments, there are anesthesiological options that can help to reduce the risk of SSI. In addition to heat, volume and transfusion management these include, for example, the use of antibiotics and the choice of the anesthesia procedure. This article is intended to provide fundamental knowledge on SSI, shows various options for reducing them in the context of anesthesia and evaluates their effectiveness and evidence based on the current state of knowledge.

Neutrophils and Anesthetic Drugs: Implications in Onco-Anesthesia

Apart from being a significant line of defense in the host defense system, neutrophils have many immunological functions. Although there are not many publications that accurately present the functions of neutrophils in relation to oncological pathology, their activity and implications have been studied a lot recently. This review aims to extensively describe neutrophils functions'; their clinical implications, especially in tumor pathology; the value of clinical markers related to neutrophils; and the implications of neutrophils in onco-anesthesia. This review also aims to describe current evidence on the influence of anesthetic drugs on neutrophils' functions and their potential influence on perioperative outcomes.

Volatile anesthetic isoflurane exposure facilitates Enterococcus biofilm infection

Enterococcus faecalis (E. faecalis) is one of the major pathogenic bacteria responsible for surgical site infections. Biofilm infections are major hospital-acquired infections. Previous studies suggested that ions could regulate biofilm formation in microbes. Volatile anesthetics, frequently administered in surgical setting, target ion channels. Here, we investigated the role of ion channels/transporters and volatile anesthetics in the biofilm formation by E. faecalis MMH594 strain and its ion transporter mutants. We found that a chloride transporter mutant significantly reduced biofilm formation compared to the parental strain. Downregulation of teichoic acid biosynthesis in the chloride transporter mutant impaired biofilm matrix formation and cellular adhesion, leading to mitigated biofilm formation. Among anesthetics, isoflurane exposure enhanced biofilm formation in vitro and in vivo. The upregulation of de novo purine biosynthesis pathway by isoflurane exposure potentially enhanced biofilm formation, an essential process for DNA, RNA, and ATP synthesis. We also demonstrated that isoflurane exposure to E. faecalis increased cyclic-di-AMP and extracellular DNA production, consistent with the increased purine biosynthesis. We further showed that isoflurane enhanced the enzymatic activity of phosphoribosyl pyrophosphate synthetase (PRPP-S). With the hypothesis that isoflurane directly bound to PRPP-S, we predicted isoflurane binding site on it using rigid docking. Our study provides a better understanding of the underlying mechanisms of E. faecalis biofilm formation and highlights the potential impact of an ion transporter and volatile anesthetic on this process. These findings may lead to the development of novel strategies for preventing E. faecalis biofilm formation and improving patient outcomes in clinical settings.

Effects of propofol on macrophage activation and function in diseases

Macrophages work with monocytes and dendritic cells to form a monocyte immune system, which constitutes a powerful cornerstone of the immune system with their powerful antigen presentation and phagocytosis. Macrophages play an essential role in infection, inflammation, tumors and other pathological conditions, but these cells also have non-immune functions, such as regulating lipid metabolism and maintaining homeostasis. Propofol is a commonly used intravenous anesthetic in the clinic. Propofol has sedative, hypnotic, anti-inflammatory and anti-oxidation effects, and it participates in the body’s immunity. The regulation of propofol on immune cells, especially macrophages, has a profound effect on the occurrence and development of human diseases. We summarized the effects of propofol on macrophage migration, recruitment, differentiation, polarization, and pyroptosis, and the regulation of these propofol-regulated macrophage functions in inflammation, infection, tumor, and organ reperfusion injury. The influence of propofol on pathology and prognosis via macrophage regulation is also discussed. A better understanding of the effects of propofol on macrophage activation and function in human diseases will provide a new strategy for the application of clinical narcotic drugs and the treatment of diseases.

Risk factors for pediatric surgical site infection following neurosurgical procedures for hydrocephalus: a retrospective single-center cohort study

Background

Infection is a major complication following cerebral spinal fluid (CSF) diversion procedures for hydrocephalus. However, pediatric risk factors for surgical site infection (SSI) are currently not well defined. Because a SSI prevention bundle is increasingly introduced, the purpose of this study was to evaluate risk factors associated with SSIs following CSF diversion surgeries following a SSI bundle at a single quaternary care pediatric hospital.

Methods

We performed a retrospective cohort study of patients undergoing CSF diversion procedures from 2017 to 2019. SSIs were identified prospectively through continuous surveillance. We performed unadjusted logistic regression analyses and univariate analyses to determine an association between SSIs and patient demographics, comorbidities and perioperative factors to identify independent risk factors for SSI.

Results

We identified a total of 558 CSF diversion procedures with an overall SSI rate of 3.4%. The SSI rates for shunt, external ventricular drain (EVD) placement, and endoscopic third ventriculostomy (ETV) were 4.3, 6.9 and 0%, respectively. Among 323 shunt operations, receipt of clindamycin as perioperative prophylaxis and presence of cardiac disease were significantly associated with SSI (O.R. 4.99, 95% C.I. 1.27–19.70, p = 0.02 for the former, and O.R. 7.19, 95% C.I. 1.35–38.35, p = 0.02 for the latter). No risk factors for SSI were identified among 72 EVD procedures.

Conclusion

We identified receipt of clindamycin as perioperative prophylaxis and the presence of cardiac disease as risk factors for SSI in shunt procedures. Cefazolin is recommended as a standard antibiotic for perioperative prophylaxis. Knowing that unsubstantiated beta-lactam allergy label is a significant medical problem, efforts should be made to clarify beta-lactam allergy status to maximize the number of patients who can receive cefazolin for prophylaxis before shunt placement. Further research is needed to elucidate the mechanism by which cardiac disease may increase SSI risk after shunt procedures.

Surgical Site Infections and Perioperative Optimization of Host Immunity by Selection of Anesthetics

Surgical site infections are significant health care issues, and efforts to mitigate their occurrence have been ongoing worldwide, mainly focusing to reduce the spillage of microbes to the otherwise sterile tissues. Optimization of host immunity has been also recognized including temperature regulation (normothermia), adequate oxygenation, and glucose management. A number of papers have described the role of anesthetics in host immunity. The role of anesthetics in postoperative outcomes including surgical site infections has been also studied. We will review the current literature and propose the importance of anesthetic selection to potentially mitigate surgical site infections.

The Role of Anesthetic Management in Surgical Site Infections After Pediatric Intestinal Surgery

BACKGROUND

Although surgical site infections (SSIs) remain a significant health care issue, a limited number of studies have analyzed risk factors for SSIs in children, particularly the role of intraoperative anesthetic management. Pediatric patients are less likely to have major adult risk factors for SSIs such as smoking and diabetes. Thus children may be more suitable as a cohort for examining the role of intraoperative anesthetics in SSIs.

AIM

We examined an association between SSI incidence and anesthetic management in children who underwent elective intestinal surgery in a single institution.

METHODS

We performed a retrospective study of 621 patients who underwent elective intestinal surgery under general anesthesia between January 2017 and September 2019, with primary outcome as the incidence of SSIs. We compared patients who were dichotomized in accordance with the median of the sevoflurane dose. We used propensity score (PS) pairwise matching of these patients to avoid selection biases. PS matching yielded 204 pairs of patients.

RESULTS

We found that higher doses of sevoflurane were associated with a higher incidence of SSIs (9.8% versus 3.9%, P = 0.019). We adjusted for intraoperative factors that were not included in the PS adjustment factors, and multivariate regression analysis after PS matching showed compatible results (odds ratio: 2.58, 95% confidence interval: 1.11-6.04, P = 0.028).

CONCLUSIONS

Higher doses of sevoflurane are associated with increased odds of SSIs after pediatric elective intestinal surgery. A randomized controlled study of volatile anesthetic-based versus intravenous anesthetic-based anesthesia will be needed to further determine the role of anesthetic drugs in SSI risk.

Risk-adjustment models for clean and colorectal surgery surgical site infection for the Spanish health system

OBJECTIVE

To develop risk-adjusted models for two quality indicators addressing surgical site infection (SSI) in clean and colorectal surgery, to be used for benchmarking and quality improvement in the Spanish National Health System.

STUDY DESIGN

A literature review was undertaken to identify candidate adjustment variables. The candidate variables were revised by clinical experts to confirm their clinical relevance to SSI; experts also offered additional candidate variables that were not identified in the literature review. Two risk-adjustment models were developed using multiple logistic regression thus allowing calculation of the adjusted indicator rates.

DATA SOURCE

The two SSI indicators, with their corresponding risk-adjustment models, were calculated from administrative databases obtained from nine public hospitals. A dataset was obtained from a 10-year period (2006-2015), and it included data from 21 571 clean surgery patients and 6325 colorectal surgery patients.

ANALYSIS METHODS

Risk-adjustment regression models were constructed using Spanish National Health System data. Models were analysed so as to prevent overfitting, then tested for calibration and discrimination and finally bootstrapped.

RESULTS

Ten adjustment variables were identified for clean surgery SSI, and 23 for colorectal surgery SSI. The final adjustment models showed fair calibration (Hosmer-Lemeshow: clean surgery χ2 = 6.56, P = 0.58; colorectal surgery χ2 = 6.69, P = 0.57) and discrimination (area under receiver operating characteristic [ROC] curve: clean surgery 0.72, 95% confidence interval [CI] 0.67-0.77; colorectal surgery 0.62, 95% CI 0.60-0.65).

CONCLUSIONS

The proposed risk-adjustment models can be used to explain patient-based differences among healthcare providers. They can be used to adjust the two proposed SSI indicators.

Perioperative and anesthetic risk factors of surgical site infection in patients undergoing pancreaticoduodenectomy: A retrospective cohort study

Background

Surgical site infection is a major perioperative issue. The morbidity of surgical site infection is high in major digestive surgery, such as pancreaticoduodenectomy. The comprehensive risk factors, including anesthetic factors, for surgical site infection in pancreaticoduodenectomy are unknown. The aim of this study was to investigate the perioperative and anesthetic risk factors of surgical site infection in pancreaticoduodenectomy.

Methods

This was a retrospective cohort study conducted in a single tertiary care center. A total of 326 consecutive patients who underwent pancreaticoduodenectomy between January 2009 and March 2018 were evaluated. Patients who underwent resection of other organs were excluded. The primary outcome was the incidence of surgical site infection, based on a Clavien-Dindo classification of grade 2 or higher. Multivariable logistic regression analysis was performed to investigate the association between surgical site infection and perioperative and anesthetic factors.

Results

Of the 326 patients, 116 (35.6%) were women. The median age was 70 years (interquartile range; 64–75). The median duration of surgery was 10.9 hours (interquartile range; 9.5–12.4). Surgical site infection occurred in 60 patients (18.4%). The multivariable analysis revealed that the use of desflurane as a maintenance anesthetic was associated with a significantly lower risk of surgical site infection than sevoflurane (odds ratio, 0.503; 95% confidence interval [CI], 0.260–0.973). In contrast, the duration of surgery (odds ratio, 1.162; 95% CI, 1.017–1.328), cerebrovascular disease (odds ratio, 3.544; 95% CI, 1.326–9.469), and ischemic heart disease (odds ratio, 10.839; 95% CI, 1.887–62.249) were identified as significant risk factors of surgical site infection.

Conclusions

Desflurane may be better than sevoflurane in preventing surgical site infection in pancreaticoduodenectomy. Cerebrovascular disease and ischemic heart disease are potential newly-identified risk factors of surgical site infection in pancreaticoduodenectomy.

Volatile anesthetics affect macrophage phagocytosis

Background

Perioperative infections, particularly surgical site infections pose significant morbidity and mortality. Phagocytosis is a critical step for microbial eradication. We examined the effect of commonly used anesthetics on macrophage phagocytosis and its mechanism.

Methods

The effect of anesthetics (isoflurane, sevoflurane, propofol) on macrophage phagocytosis was tested using RAW264.7 mouse cells, mouse peritoneal macrophages, and THP-1 human cells. Either opsonized sheep erythrocytes or fluorescent labeled Escherichia coli were used as phagocytic objects. The activation of Rap1, a critical protein in phagocytosis was assessed using the active Rap1 pull-down and detection kit. To examine anesthetic binding site(s) on Rap1, photolabeling experiments were performed using azi-isoflurane and azi-sevoflurane. The alanine scanning mutagenesis of Rap1 was performed to assess the role of anesthetic binding site in Rap1 activation and phagocytosis.

Results

Macrophage phagocytosis was significantly attenuated by the exposure of isoflurane (50% reduction by 1% isoflurane) and sevoflurane (50% reduction by 1.5% sevoflurane), but not by propofol. Photolabeling experiments showed that sevoflurane directly bound to Rap1. Mutagenesis analysis demonstrated that the sevoflurane binding site affected Rap1 activation and macrophage phagocytosis.

Conclusions

We showed that isoflurane and sevoflurane attenuated macrophage phagocytosis, but propofol did not. Our study showed for the first time that sevoflurane served as a novel small GTPase Rap1 inhibitor. The finding will further enrich our understanding of yet-to-be determined mechanism of volatile anesthetics and their off-target effects. The sevoflurane binding site was located outside the known Rap1 functional sites, indicating the discovery of a new functional site on Rap1 and this site would serve as a pocket for the development of novel Rap1 inhibitors.

Analgesia after major laparoscopic surgery in patients with chronic kidney disease: A retrospective cohort study

The amount of reduction in opioid doses and its effect on postoperative pain outcomes in chronic kidney disease (CKD) patients in the perioperative setting remains unclear. This study aimed to investigate differences in postoperative pain outcomes after major laparoscopic surgery between patients with CKD and those with normal preoperative kidney function. Medical records of patients who underwent laparoscopic major abdominal surgery from January 2010 to December 2016 were retrospectively reviewed, and 6,612 patients were finally included. During postoperative day (POD) 0–3, patients with an estimated glomerular filtration rate (eGFR) < 30 mL min⁻¹ 1.73 m⁻² had 3.5% lower morphine equivalent consumption than those with an eGFR ≥ 90 mL min⁻¹ 1.73 m⁻² (P = 0.023), whereas patients with preoperative eGFR between 60–90 mL min⁻¹ 1.73 m⁻² and 30–60 mL min⁻¹ 1.73 m⁻² showed no significant differences in morphine equivalent consumption. Additionally, pain scores at rest during POD 0–3 were not significantly associated with preoperative kidney function. In conclusion, our results suggest that patients with mild to moderate CKD (stage 2–3) did not require reduction of opioid analgesics during POD 0–3, compared to patients with normal preoperative kidney function. Only patients with severe CKD (stage ≥ 4) might require a slight reduction of opioid analgesics.

Reduction of oxidative stress a key for enhanced postoperative recovery with fewer complications in esophageal surgery patients: Randomized control trial to investigate therapeutic impact of anesthesia management and usefulness of simple blood test for prediction of high-risk patients

BACKGROUND

Oxidative stress may be an integral determinant of surgical stress severity. We examined whether the preoperative level of derivatives of reactive oxygen metabolites (d-ROMs), an oxidative stress biomarker based on total hydroperoxides in circulating blood, is predictive of increased risk of delayed recovery and complications after surgery, as well as the effects of anesthesia management on postoperative recovery in light of oxidative stress.

METHODS

Patients (American Society of Anesthesiologists physical status I-II) scheduled for a radical esophagectomy (n = 186) were randomly selected to receive inhalational sevoflurane (n = 94) or intravenous propofol (n = 92) anesthesia. Preoperative blood d-ROMs level, as well as pre-and postoperative plasma ferric-reducing ability, were analyzed to assess oxidative stress, with white blood cell (WBC) count, C-reactive protein (CRP) level, incidence of severe postoperative complications, and postoperative recovery process within 30 days after surgery also examined in a double-blind fashion.

RESULTS

Postoperative normalization of WBC and CRP was extended in patients with elevated preoperative d-ROMs [WBC versus d-ROMs: correlation coefficient (r) = 0.58 P < .001; CRP versus d-ROMs: r = 0.46 P < .001]. Receiver operating characteristics analysis of d-ROMs in relation to incidence of severe postoperative complications revealed an optimum d-ROMs threshold value of 410 UCarr and that patients with ≥410 UCarr had a greater risk of complications as compared to those with lower values (odds ratio = 4.7). Plasma ferric-reducing ability was decreased by 61 ± 185 mmol·l (P < .001) after surgery, demonstrating development of surgery-related oxidative stress, the magnitude of which was positively correlated with preoperative d-ROMs level (r = 0.16, P = .043). A comparison of the 2 anesthesia management protocols showed that patients who received propofol, an antioxidant anesthetic, had no postoperative decrease in ferric-reducing ability, lower incidence of severe postoperative complications (7 of 92 versus 18 of 94, P = .030, odds ratio = 0.35), and faster uneventful recovery time (WBC normalization days 7.1 ± 5.2 versus 13.6 ± 10.2, P < .001) as compared to those who received sevoflurane.

CONCLUSIONS

Elevated preoperative blood d-ROMs predicts greater intraoperative oxidative stress and increased postoperative complications with prolonged recovery, thus is useful for identifying high-risk patients for delayed and complicated surgical recovery. Reduction of oxidative stress is vital for enhanced recovery, with control by antioxidants such as propofol a possible solution.

Volatile Anesthetic Attenuates Phagocyte Function and Worsens Bacterial Loads in Wounds

BACKGROUND

Previously we have shown that volatile anesthetic isoflurane attenuated neutrophil recruitment and phagocytosis in mouse sepsis and skin inflammation models. The objectives of this study were to test ex vivo function of neutrophils in patients who underwent cardiac catheterization under volatile anesthesia versus intravenous anesthesia (IA), and also to assess the effect of anesthesia on surgical site infections (SSIs) using mouse model to understand the clinical relevance of anesthesia-induced immunomodulation.

METHODS

Whole blood from patients who underwent cardiac catheterization procedures either by volatile anesthesia or IA was collected and subjected to phagocytosis assay and a lipopolysaccharide-induced tumor necrosis factor-α assay. Mouse SSI with Staphylococcus aureus USA300 was created, and the effect of isoflurane and propofol exposure (short or long exposure) on bacterial loads was tested.

RESULTS

Neutrophil phagocytosis was significantly attenuated after the induction of volatile anesthesia in patients, but not by IA. Monocyte phagocytosis was not affected by the anesthesia regimen. Bacterial loads following SSIs were significantly higher in mice receiving long, but not short, isoflurane exposure. Propofol exposure did not affect bacterial loads.

DISCUSSION

Neutrophil phagocytosis can be affected by the type of anesthesia, and preclinical model of SSIs showed potential clinical relevance. The effects of anesthesia regimen on SSIs in patients needs to be studied extensively in the future.

Suspected periprosthetic joint infection after total knee arthroplasty under propofol versus sevoflurane anesthesia: a retrospective cohort study

PURPOSE

Periprosthetic joint infection is a serious complication of total knee arthroplasty. Though there are many factors that might increase its risk, the use of propofol for maintaining general anesthesia could theoretically increase the incidence of infection because of its lipid component that supports bacterial growth. Nevertheless, the relationship between anesthetic maintenance agents and the occurrence of periprosthetic joint infection remains uncertain. The purpose of this study was to compare the incidence of suspected early-onset periprosthetic joint infection between patients undergoing total knee arthroplasty under propofol vs sevoflurane anesthesia.

METHODS

We conducted a retrospective cohort study of patients in the national inpatient Diagnosis Procedure Combination database in Japan who underwent total knee arthroplasty. Suspected periprosthetic joint infection was surrogately defined as the need for arthrocentesis or debridement within 30 days of surgery. Propensity score matching was performed between patients who received either propofol or sevoflurane for anesthetic maintenance to determine the proportion of those with infection.

RESULTS

Eligible patients (n = 21,899) were categorized into either the propofol (n = 7,439) or sevoflurane (n = 14,460) groups. In the 5,140 propensity-matched patient pairs, there was no significant difference in the proportion of arthrocentesis or debridement [1.3% propofol vs 1.7% sevoflurane; respectively (relative risk, 0.76; 95% CI, 0.55 to 1.04; P = 0.10)] between the groups. The mean (SD) length of stay in the propofol group was significantly longer than in the sevoflurane group [32.5 (18.4) days vs 31.4 (14.4) days, respectively; mean difference, 1.1; 95% CI, 0.5 to 1.8; P < 0.001].

CONCLUSION

Propensity score analysis suggested no significant association between the choice of anesthetic maintenance agent and the occurrence of suspected early-onset periprosthetic joint infection in patients undergoing total knee arthroplasty.