Circulating interleukin 6 as a useful marker for predicting postoperative complications

Perioperative Ketamine and Cancer Recurrence: A Comprehensive Review

Cancer is a significant global health threat and a leading cause of death worldwide. Effective early-stage interventions, particularly surgery, can potentially cure many solid tumors. However, the risk of postoperative cancer recurrence remains high. Recent research highlights the influence of perioperative anesthetic and analgesic choices on the fate of residual cancer cells, potentially affecting recurrence risks. Among these agents, ketamine-a well-known anesthetic and analgesic-has garnered interest due to its antitumor properties, mainly through inhibiting the N-methyl-D-aspartate (NMDA) receptor found in various cancer tissues. Additionally, ketamine's potential immunomodulatory effects, given the expression of NMDA receptors on immune cells, suggest that it plays a significant role during the perioperative period. This review synthesizes current evidence on ketamine's impact on cancer cell biology, inflammation, immune modulation, and the role of the gut microbiota, proposing ketamine as a promising agent for enhancing oncological outcomes.

Serum Interleukin-6 as a Biomarker for Early Prediction of Post-Operative Infectious Complications After Elective Pancreatectomy

Background: To investigate whether interleukin (IL)-6 could predict the post-operative complications of elective pancreatectomy early. Patients and Methods: Overall, 122 patients who underwent elective pancreatectomy from June 2020 to May 2021 in our hospital were enrolled. Interleukin-6 was measured on the day before and at six hours after surgery, and on post-operative day one, three, and five. The associations between IL-6 level and post-operative complications were analyzed, and the predictive value of IL-6 for complications was assessed. Results: Sixty-three patients developed post-operative complications. Higher IL-6 was observed in patients with post-operative complications on post-operative day one, post-operative day three, and post-operative day five, with odd ratios of 1.43, 1.68, and 2.54 (p = 0.01, p = 0.01, and p = 0.01), respectively. These trends were also observed in patients with infectious complications preoperatively, on post-operative day one, post-operative day three, and post-operative day five, with ORs of 2.46, 1.95, 2.01, and 2.49 (p = 0.00, 0.00, 0.01, 0.00) respectively. Multivariate regression revealed that IL-6 is the only predictor for infectious complications on post-operative day one (p = 0.016). Based on the optimal cutoffs, pre-operative IL-6, IL-6 on post-operative day one and post-operative day three for predicting infectious complications yielded area under the curve (AUC) of 0.73, 0.70, and 0.70, with high negative predictive value of 82.7%, 92.2%, and of 91.3%, respectively. Conclusions: This study validated the early predictive value of IL-6 on infectious complications after pancreatectomy. Because of the performance of serum IL-6 in predicting infectious complications and high NPV, we endorse that IL-6 could be a potential biomarker for early prediction and antibiotic optimization after pancreatectomy.

Ketamine as a therapeutic agent for depression and pain: mechanisms and evidence

Ketamine is an anesthetic drug which is now used to treat chronic pain conditions and psychiatric disorders, especially depression. It is an N-methyl-D-aspartate (NMDA) receptor antagonist with additional effects on α-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, hyperpolarization-activated cyclic nucleotide-gated (HCN) channels, opioid receptors, and monoaminergic receptors. This article focuses on ketamine's role in treating depression and pain, two commonly comorbid challenging conditions with potentially shared neurobiologic circuitry. Many clinical trials have utilized intravenous or intranasal ketamine for treating depression and pain. Intravenous ketamine is more bioavailable than intranasal ketamine and both are effective for acute depressive episodes. Intravenous ketamine is advantageous for post-operative analgesia and is associated with a reduction in total opioid requirements. Few studies have treated chronic pain or concurrent depression and pain with ketamine. Larger, randomized control trials are needed to examine the safety and efficacy of intravenous vs. intranasal ketamine, ideal target populations, and optimal dosing to treat both depression and pain.

Measuring the human immune response to surgery: multiomics for the prediction of postoperative outcomes

PURPOSE OF REVIEW

Postoperative complications including infections, cognitive impairment, and protracted recovery occur in one-third of the 300 million surgeries performed annually worldwide. Complications cause personal suffering along with a significant economic burden on our healthcare system. However, the accurate prediction of postoperative complications and patient-targeted interventions for their prevention remain as major clinical challenges.

RECENT FINDINGS

Although multifactorial in origin, the dysregulation of immunological mechanisms that occur in response to surgical trauma is a key determinant of postoperative complications. Prior research, primarily focusing on inflammatory plasma markers, has provided important clues regarding their pathogenesis. However, the recent advent of high-content, single-cell transcriptomic, and proteomic technologies has considerably improved our ability to characterize the immune response to surgery, thereby providing new means to understand the immunological basis of postoperative complications and to identify prognostic biological signatures.

SUMMARY

The comprehensive and single-cell characterization of the human immune response to surgery has significantly advanced our ability to predict the risk of postoperative complications. Multiomic modeling of patients' immune states holds promise for the discovery of preoperative predictive biomarkers, ultimately providing patients and surgeons with actionable information to improve surgical outcomes. Although recent studies have generated a wealth of knowledge, laying the foundation for a single-cell atlas of the human immune response to surgery, larger-scale multiomic studies are required to derive robust, scalable, and sufficiently powerful models to accurately predict the risk of postoperative complications in individual patients.

Postoperative Natural Killer Cell Dysfunction: The Prime Suspect in the Case of Metastasis Following Curative Cancer Surgery

Surgical resection is the foundation for the curative treatment of solid tumors. However, metastatic recurrence due to the difficulty in eradicating micrometastases remain a feared outcome. Paradoxically, despite the beneficial effects of surgical removal of the primary tumor, the physiological stress resulting from surgical trauma serves to promote cancer recurrence and metastasis. The postoperative environment suppresses critical anti-tumor immune effector cells, including Natural Killer (NK) cells. The literature suggests that NK cells are critical mediators in the formation of metastases immediately following surgery. The following review will highlight the mechanisms that promote the formation of micrometastases by directly or indirectly inducing NK cell suppression following surgery. These include tissue hypoxia, neuroendocrine activation, hypercoagulation, the pro-inflammatory phase, and the anti-inflammatory phase. Perioperative therapeutic strategies designed to prevent or reverse NK cell dysfunction will also be examined for their potential to improve cancer outcomes by preventing surgery-induced metastases.

Trauma of major surgery: A global problem that is not going away

Globally, a staggering 310 million major surgeries are performed each year; around 40 to 50 million in USA and 20 million in Europe. It is estimated that 1–4% of these patients will die, up to 15% will have serious postoperative morbidity, and 5–15% will be readmitted within 30 days. An annual global mortality of around 8 million patients places major surgery comparable with the leading causes of death from cardiovascular disease and stroke, cancer and injury. If surgical complications were classified as a pandemic, like HIV/AIDS or coronavirus (COVID-19), developed countries would work together and devise an immediate action plan and allocate resources to address it. Seeking to reduce preventable deaths and post-surgical complications would save billions of dollars in healthcare costs. Part of the global problem resides in differences in institutional practice patterns in high- and low-income countries, and part from a lack of effective perioperative drug therapies to protect the patient from surgical stress. We briefly review the history of surgical stress and provide a path forward from a systems-based approach. Key to progress is recognizing that the anesthetized brain is still physiologically ‘awake’ and responsive to the sterile stressors of surgery. New intravenous drug therapies are urgently required after anesthesia and before the first incision to prevent the brain from switching to sympathetic overdrive and activating secondary injury progression such as hyperinflammation, coagulopathy, immune activation and metabolic dysfunction. A systems-based approach targeting central nervous system-mitochondrial coupling may help drive research to improve outcomes following major surgery in civilian and military medicine.

Acute Cytokine Response During Breast Cancer Surgery: Potential Role of Dexamethasone and Lidocaine and Relationship with Postoperative Pain and Complications - Analysis of Three Pooled Pilot Randomized Controlled Trials

Purpose

An imbalance in perioperative cytokine response may cause acute pain and postoperative complications. Anesthetic drugs modulate this cytokine response, but their role in non-major breast cancer surgery is unclear. In an exploratory study, we investigated whether intravenous lidocaine and dexamethasone could modulate the cytokine response into an anti-inflammatory direction. We also evaluated interrelationships between cytokine levels, pain scores and postoperative complications. Our goal is to develop multimodal analgesia regimens optimizing outcome after breast cancer surgery.

Patients and Methods

Forty-eight patients undergoing a lumpectomy were randomly assigned to placebo or lidocaine (1.5 mg⋅kg⁻¹ followed by 2 mg⋅kg⁻¹⋅hour⁻¹) supplemented by dexamethasone zero, 4 or 8 mg, yielding six groups of eight patients. Interleukin (IL)-1β, IL-1Ra, IL-6, IL-10 levels and pain scores were measured at baseline and four hours postoperatively. We assessed postoperative complications occurring within 30 days. We noted persistent pain and infections as potential immune-related complications (PIRC). We used multiple regression to disentangle the effects of the individual study drugs (given by their partial regression coefficients (b)). Odds ratios (OR) estimated the link between pain scores and complications.

Results

Dexamethasone 8 mg increased IL-10 (b=12.70 (95% CI=8.06–17.34), P<0.001). Dexamethasone 4 mg and 8 mg decreased the ratio IL-6/IL-10 (b=−2.60 (−3.93 to −1.26), P<0.001 and b=−3.59 (−5.04 to −2.13), P<0.001, respectively). We could not show modulatory effects of lidocaine on cytokines. High pain scores were linked to the occurrence of PIRC’s (OR=2.028 (1.134–3.628), P=0.017). Cytokine levels were not related either to acute pain or PIRC.

Conclusion

Dexamethasone modulated the perioperative cytokine response into an anti-inflammatory direction. An overall lidocaine effect was not found. Patients with higher pain scores suffered from more 30-day PIRCs. Cytokine levels were not associated with pain or more postoperative complications, even not with PIRC. Larger studies in breast cancer surgery are needed to confirm these explorative results.

The association between the inflammatory response to surgery and postoperative complications in older patients with cancer; a prospective prognostic factor study

BACKGROUND

Accurate prognostic biomarkers would substantially improve surgical planning and decisions making yet no studies have been reported exploring the inflammatory response in surgically treated older patients with cancer. The aim of this study was to explore inflammatory biomarkers as potential prognostic factors for postoperative complications within 30 days in older patients with cancer.

METHOD

Patients 65 years and older undergoing surgery for removal of a solid malignant tumour were included in an observational cohort study. All complications occurring up to 30 days postoperatively were documented prospectively. Inflammatory markers were measured in plasma samples pre- and postoperatively: C-reactive protein (CRP), Interleukin-1 beta (IL-1β), IL-6, IL-10, IL-12, and Tumour necrosis factor-alpha (TNF-α). Associations between inflammatory markers and postoperative complications were explored using logistic regression analysis.

RESULTS

Between July 2010 and April 2014, plasma samples of 224 patients were collected. Median age was 72 (65-89) years and 116 (51.8%) patients were female. Approximately half of the patients developed postoperative complications (49.6%) of whom 62 patients (55.9%) developed >1 complication. An independent prognostic effect was observed for the inflammatory biomarkers IL-6 and IL-10 for the occurrence of postoperative complications.

CONCLUSION

The perioperative inflammatory response is associated with complications, independently from patient and surgical factors which are also associated with outcome. Research is warranted towards further exploration of the perioperative inflammatory response with the aim to improve perioperative care and outcome, and might help to improve surgical planning and decision making for older patients with cancer.

Multimodal analgesia in pain management after spine surgery

Multimodal analgesia (MMA) is the simultaneous use of multiple analgesic medications that work in a synergistic manner to provide pain control. In recent years, spine surgery has seen the growth of multimodal perioperative protocols for managing pain. Postoperative pain following spinal procedures is a common complaint, with persistent pain even after the immediate convalescent period leading to negative impacts on health. A multidisciplinary approach is essential in reducing postoperative morbidity and complication rates. This review demonstrates the efficacy in the combined use of opioid-alternative medications such as NSAIDs, gabapentinoids, local anesthetics, acetaminophen, and other neuromodulatory pharmacologic agents. Continued research will be essential in the optimization of the MMA protocol for treating patients who undergo spine procedures.

Effects of propofol on the inflammatory response during robot-assisted laparoscopic radical prostatectomy: a prospective randomized controlled study

Robot-assisted laparoscopic radical prostatectomy (RALRP) is a minimally invasive procedure; however, some amount of surgical trauma that can trigger systemic inflammation remains. Moreover, pneumoperitoneum during RALRP induces ischemia–reperfusion injury (IRI). Propofol, an anesthetic, is known to have anti-inflammatory and antioxidant properties. In the present study, we compared the effects of propofol with those of desflurane on inflammation and IRI during RALRP via measurements of different biomarkers and evaluation of perioperative renal function. Fifty patients were randomized to receive either desflurane (n = 25) or propofol (n = 25) with remifentanil during RALRP. Serum levels of interleukin (IL)-6 (IL-6), tumor necrosis factor alpha, C-reactive protein, and nitric oxide were measured 10 min after anesthesia induction (T1), 100 min after carbon dioxide (CO₂) insufflation (T2), and 10 min after CO₂ deflation (T3). Perioperative urine outputs and the serum creatinine level at 24 h after surgery were also recorded. We found that IL-6 levels at T2 and T3 were higher than those at T1 in both groups, although the increases were significant attenuated only in the propofol group. The other parameters showed no differences among the three time points in both groups. The intraoperative urine output was significantly higher in the propofol group than in the desflurane group, while the creatinine level showed no significant changes in either group. Our findings suggest that propofol can not only attenuate the inflammatory response during and after pneumoperitoneum in patients undergoing RALRP but also prevent oliguria during pneumoperitoneum.

Effect of Propofol on the Production of Inflammatory Cytokines by Human Polarized Macrophages

Macrophages are key immune system cells involved in inflammatory processes. Classically activated (M1) macrophages are characterized by strong antimicrobicidal properties, whereas alternatively activated (M2) macrophages are involved in wound healing. Severe inflammation can induce postoperative complications during the perioperative period. Invasive surgical procedures induce polarization to M1 macrophages and associated complications. As perioperative management, it is an important strategy to regulate polarization and functions of macrophages during inflammatory processes. Although propofol has been found to exhibit anti-inflammatory activities in monocytes and macrophages, it is unclear whether propofol regulates the functions of M1 and M2 macrophages during inflammatory processes. This study therefore investigated the effects of propofol on human macrophage polarization. During M1 polarization, propofol suppressed the production of IL-6 and IL-1β but did not affect TNF-α production. In contrast, propofol did not affect the gene expression of M2 markers, such as IL-10, TGF-β, and CD206, during M2 polarization. Propofol was similar to the GABA_A agonist muscimol in inducing nuclear translocation of nuclear factor-E2-related factor 2 (Nrf2) and inhibiting IL-6 and IL-1β, but not TNF-α, production. Knockdown of Nrf2 using siRNA significantly reduced the effect of propofol on IL-6 and IL-1β production. These results suggest that propofol prevents inflammatory responses during polarization of human M1 macrophages by suppressing the expression of IL-6 and IL-1β through the GABA_A receptor and the Nrf2-mediated signal transduction pathway.

In-hospital complication rate following microendoscopic versus open lumbar laminectomy: a propensity score-matched analysis

BACKGROUND CONTEXT

The incidence of postoperative complications after microendoscopic laminectomy (MEL) has not been compared with that after open laminectomy in a large study, so it is not clear whether MEL is a safer procedure.

PURPOSE

The objective of this study was to compare postoperative morbidity and mortality following lumbar laminectomy between patients treated with MEL and with open laminectomy.

STUDY DESIGN

This is a retrospective cohort study with propensity score-matched analysis.

PATIENT SAMPLE

Data of patients who underwent elective spinal surgery between July 2010 and March 2013 were extracted from the Diagnosis Procedure Combination database, a nationwide inpatient database in Japan.

OUTCOME MEASURES

Clinical outcomes included length of hospital stay, occurrence of major complications (cardiac events, respiratory complications, pulmonary embolism, stroke, and acute renal failure), surgical site infection (SSI), postoperative delirium, and in-hospital death.

MATERIALS AND METHODS

Propensity score matching was performed to adjust for measured confounding factors, including patient age, sex, Charlson Comorbidity Index, body mass index, smoking status, blood transfusion, duration of anesthesia, number of operated disc levels, and type of hospital and hospital volumes. The clinical outcomes of one-to-one propensity-matched pairs of the MEL and the open laminectomy groups were compared.

RESULTS

Of 23,317 patients identified in the database, 1,536 underwent MEL (6.6%). By one-to-one propensity score matching, 1,536 pairs were selected. The distributions of patient backgrounds were closely balanced between the MEL and the open laminectomy groups. An analysis of 1,536 pairs revealed that there was a significantly lower incidence of major postoperative complications in those who underwent MEL (1.0% vs. 2.8% for open laminectomy, risk difference 1.8%, 95% confidence interval [CI] 0.9%-2.9%), SSI (0.5% vs. 1.6% for open laminectomy, risk difference 1.1%, 95% CI 0.4%-1.9%), and postoperative delirium (1.1% vs. 2.3% for open laminectomy, risk difference1.2%, 95% CI 0.3%-2.1%). The length of hospital stay was significantly shorter in those treated with MEL (12 days vs. 16 days for open laminectomy, p<.001). There was no significant difference in in-hospital mortality between the groups.

CONCLUSIONS

Patients who underwent MEL were significantly less likely to experience major postoperative complications and were less likely to develop SSI and postoperative delirium than those who underwent open laminectomy.

Ketamine and Ketamine Metabolite Pharmacology: Insights into Therapeutic Mechanisms

Ketamine, a racemic mixture consisting of (S)- and (R)-ketamine, has been in clinical use since 1970. Although best characterized for its dissociative anesthetic properties, ketamine also exerts analgesic, anti-inflammatory, and antidepressant actions. We provide a comprehensive review of these therapeutic uses, emphasizing drug dose, route of administration, and the time course of these effects. Dissociative, psychotomimetic, cognitive, and peripheral side effects associated with short-term or prolonged exposure, as well as recreational ketamine use, are also discussed. We further describe ketamine's pharmacokinetics, including its rapid and extensive metabolism to norketamine, dehydronorketamine, hydroxyketamine, and hydroxynorketamine (HNK) metabolites. Whereas the anesthetic and analgesic properties of ketamine are generally attributed to direct ketamine-induced inhibition of N-methyl-D-aspartate receptors, other putative lower-affinity pharmacological targets of ketamine include, but are not limited to, γ-amynobutyric acid (GABA), dopamine, serotonin, sigma, opioid, and cholinergic receptors, as well as voltage-gated sodium and hyperpolarization-activated cyclic nucleotide-gated channels. We examine the evidence supporting the relevance of these targets of ketamine and its metabolites to the clinical effects of the drug. Ketamine metabolites may have broader clinical relevance than was previously considered, given that HNK metabolites have antidepressant efficacy in preclinical studies. Overall, pharmacological target deconvolution of ketamine and its metabolites will provide insight critical to the development of new pharmacotherapies that possess the desirable clinical effects of ketamine, but limit undesirable side effects.

Preoperative High Dose of Methylprednisolone Improves Early Postoperative Pulmonary Function, in Super-Obese Patients Undergoing Open Surgery; a Prospective, Comparative Study

BACKGROUND

Surgery stimulates an intense systemic inflammatory response which might increase postoperative morbidity. Corticosteroids may reduce this inflammatory reaction. The purpose of this study was to investigate any possible effect on postoperative morbidity and recovery after administrating methylprednisolone in super-obese patients undergoing open surgery.

METHODS

Sixty super-obese patients with BMI ≥50 kg/m² (mean 57.48 ± 7.33), mean age of 39 ± 9 years, who underwent an open bariatric procedure, were enrolled. Thirty patients (group A) were allocated to a preoperative single dose of 30 mg/kg (ideal body weight) methylprednisolone versus placebo (group B, 30 patients). Endpoints included assessment of IL-6 and CRP; evaluation of postoperative pulmonary function, pain management, nausea, and vomiting; and documentation of postoperative complications.

RESULTS

Significant improvement in spirometry parameters and arterial blood gas analysis, in the first and third postoperative days, was observed in the methylprednisolone group. IL-6 and CRP levels were significantly lower in that group. Administration of methylprednisolone was associated with less postoperative pain, nausea, and vomiting, with no statistical difference in septic complications.

CONCLUSIONS

Preoperative administration of a single high dose of methylprednisolone in super-obese patients undergoing open surgery inhibits the inflammatory signaling cascade, lessens the systemic inflammatory response, and results in fewer pulmonary complications and better patient recovery.

Perioperative Simvastatin Therapy in Major Colorectal Surgery: A Prospective, Double-Blind Randomized Controlled Trial

BACKGROUND

Statins have numerous potential benefits relevant to abdominal surgery, and their use has been associated with a reduction in the systemic inflammatory response syndrome, wound infection, and anastomotic leak after colorectal surgery. However, this clinical evidence is limited to retrospective studies. The aim of this study was to prospectively investigate whether perioperative statin therapy can decrease the incidence of complications after major colorectal surgery.

STUDY DESIGN

A prospective, double-blind, parallel-group, randomized controlled trial was conducted at 3 tertiary hospitals in New Zealand, between October 2011 and August 2013. Adult patients undergoing elective colorectal resection for any indication or reversal of Hartmann's procedure were randomized with a 1:1 patient allocation ratio to receive either 40 mg oral simvastatin or placebo once daily for 3 to 7 days preoperatively until 14 days postoperatively. The primary outcome was the overall incidence of complications for 30 days postoperatively. Secondary outcomes included the systemic and peritoneal cytokine response (interleukin [IL]-1α, IL-1β, IL-6, IL-8, IL-10, tumor necrosis factor [TNF]α) on postoperative day 1.

RESULTS

There were 132 patients included in the study (65 simvastatin, 67 placebo). There were no significant differences between the 2 groups at baseline with regard to patient, operation, and disease characteristics. There were no significant differences between the 2 groups in the incidence, grade, and type of postoperative complications (simvastatin: 44 [68%] vs placebo: 50 [75%], odds ratio 0.71 [95% CI 0.33 to 1.52], p = 0.444). Plasma concentrations of IL-6, IL-8, and TNFα, and peritoneal concentrations of IL-6 and IL-8, were significantly lower in the simvastatin group postoperatively.

CONCLUSIONS

Perioperative simvastatin therapy in major colorectal surgery attenuates the early proinflammatory response to surgery, but there were no differences in postoperative complications.

Addressing the Global Burden of Trauma in Major Surgery

Despite a technically perfect procedure, surgical stress can determine the success or failure of an operation. Surgical trauma is often referred to as the "neglected step-child" of global health in terms of patient numbers, mortality, morbidity, and costs. A staggering 234 million major surgeries are performed every year, and depending upon country and institution, up to 4% of patients will die before leaving hospital, up to 15% will have serious post-operative morbidity, and 5-15% will be readmitted within 30 days. These percentages equate to around 1000 deaths and 4000 major complications every hour, and it has been estimated that 50% may be preventable. New frontline drugs are urgently required to make major surgery safer for the patient and more predictable for the surgeon. We review the basic physiology of the stress response from neuroendocrine to genomic systems, and discuss the paucity of clinical data supporting the use of statins, beta-adrenergic blockers and calcium-channel blockers. Since cardiac-related complications are the most common, particularly in the elderly, a key strategy would be to improve ventricular-arterial coupling to safeguard the endothelium and maintain tissue oxygenation. Reduced O2 supply is associated with glycocalyx shedding, decreased endothelial barrier function, fluid leakage, inflammation, and coagulopathy. A healthy endothelium may prevent these "secondary hit" complications, including possibly immunosuppression. Thus, the four pillars of whole body resynchronization during surgical trauma, and targets for new therapies, are: (1) the CNS, (2) the heart, (3) arterial supply and venous return functions, and (4) the endothelium. This is termed the Central-Cardio-Vascular-Endothelium (CCVE) coupling hypothesis. Since similar sterile injury cascades exist in critical illness, accidental trauma, hemorrhage, cardiac arrest, infection and burns, new drugs that improve CCVE coupling may find wide utility in civilian and military medicine.

Assessment of tissue damage due to percutaneous nephrolithotomy using serum concentrations of inflammatory mediators

OBJECTIVES

To determine the percutaneous nephrolithotomy (PCNL) effects on the tissues using the quantification of inflammatory mediators, and to assess their impact on the development of postoperative complications.

PATIENTS AND METHODS

Prospective observational non-randomized study on 40 patients underwent to PCNL. 50 patients with kidney stone who were treated by extracorporeal shock wave lithotripsy (ESWL) were used as control group. Interleukin-1beta (IL-1β), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and C-reactive protein (CRP) were determined at baseline (T0: before treatment), and at 2, 6 and 24hours after (T1, T2 and T3).

RESULTS

No relevant changes on IL-1β and TNF-α were found. IL-6 showed two peaks at 2 and 6hours post-PCNL (median 17.8 and 15.8 pg/mL, respectively). At 24hours CRP had reached its peak value (3.4mg/L). The group treated with ESWL no showed significant changes in any of the markers. The serum concentration of IL-6 and CRP at 24hours post-NLP is different depending on the occurrence of complications (P=.001 and P=.039, respectively). IL-6 showed a good predictive power for the development of complications (AUC .801).

CONCLUSIONS

Tissue damage caused by the PCNL is low. This damage increases significantly in those cases showing postoperative complications. IL-6 at 24hours has been shown to be a good predictive tool for the development of complications.

Cerebral protection: inflammation, endothelial dysfunction, and postoperative cognitive dysfunction

PURPOSE OF REVIEW

Postoperative cognitive dysfunction (POCD) is a well recognized perioperative syndrome, with approximately 15% of patients over the age of 60 years displaying objectively measured decrease in cognitive function as a consequence of anesthesia and surgery. The exact cause, however, remains unknown. This review aims to update anesthesiologists on the recent advancements in the understanding of the pathophysiology of POCD.

RECENT FINDINGS

Recent evidence suggests that the observed predilection to POCD is likely mediated by a neuro-inflammatory response - with surgery being a major contributing factor. The blood-brain barrier, a highly specialized endothelial layer, is exquisitely sensitive to an inflammatory insult and implicated in the cause of other neurocognitive syndromes also characterized by neuro-inflammation such as cerebral malaria. Inflammatory changes may disrupt the blood-brain barrier and facilitate migration of macrophages into the brain, damaging synapses and neurones and ultimately lead to POCD. This review explores the important question of causality - the potential relationship between inflammation, endothelial dysfunction, and postoperative cognitive decline.

SUMMARY

Recent research points to a central role of a neuro-inflammatory cascade in POCD, with endothelial dysfunction potentially aggravating the insult. Investigating the genomic and molecular mechanisms that underlie the intervariation in the inflammatory response to surgery, improving the identification of appropriate endothelial and inflammatory biomarkers, and developing endothelial modulatory and anti-inflammatory (prevention and resolution) strategies are key areas of future translational research. This is important as the elderly, who show increased susceptibility to this and other perioperative illness syndromes, represent an ever-increasing proportion of patients presenting for surgery.

A prospective study to assess the levels of interleukin-6 following administration of diclofenac, ketorolac and tramadol after surgical removal of lower third molars

INTRODUCTION

The surgical removal of impacted third molars involves, trauma to soft and bony tissue and can result in considerable pain, swelling, and trismus. The greater the amount of tissue injury the greater is the amount of inflammation in the perisurgical region. Interleukin-6 (IL-6) is both a pro inflammatory and anti-inflammatory cytokine. It is secreted by T cells and macrophages to stimulate the immune response. IL-6 is also an early marker of tissue damage. In addition to NSAIDs, corticosteroids, opioids also have immunomodulatory effects.

AIM

To evaluate the changes in serum IL-6 levels following surgical removal of third molars under local anaesthesia after administration of two NSAIDs diclofenac and ketorolac and opioid tramadol post operatively.

METHODS

Patients undergoing surgical removal of impacted mandibular third molar teeth were randomly assigned to three groups. Each group received one of the three analgesics viz diclofenac 50 mg, ketorolac 10 mg and tramadol 50 mg. The mean levels of IL-6 was then estimated by ELISA.

RESULTS

The results of our study showed that all three drugs i.e. diclofenac, ketorolac and tramadol have properties which can downregulate the production of IL-6 in response to surgical trauma.

CONCLUSION

It is of clinical significance that the suppression of IL-6 values occurs in tramadol group closely following the diclofenac group. Even though the drug ketorolac suppresses the IL-6 levels similar to diclofenac initially but after 7 days tramadol and ketorolac showed similarities in suppression of IL-6 expression which is less compared to diclofenac group.

The influence of steroid administration on systemic response in laminoplasty for cervical myelopathy

INTRODUCTION

The excessive systemic inflammatory response caused by surgery has been associated with the development of major complications, such as postoperative confusion and acute respiratory distress syndrome. The serum IL-6 has been used as a predictor in the extent of surgical trauma. Several trials have reported that steroid administration reduced excessive systemic response. We investigated the systemic response caused by surgical trauma in patients with cervical laminoplasty and evaluated the influence of steroid administration on systemic response.

MATERIALS AND METHODS

Thirty patients were included in this study. The patients were divided into three groups of ten each: preoperative steroid group, intraoperative steroid group, and non-steroid group. The same dose of steroid was administered to the patients in preoperative group and intraoperative group. Venous blood samples were taken at the following times: before surgery, at the end of surgery, 6 h after the surgery, the first, the third and the seventh day after the surgery. Outcome measures were serum IL-6, IL-10, C-reactive protein (CRP), white blood cells including neutrophil and lymphocyte counts.

RESULTS

The mean serum IL-6 levels on the first day in preoperative and intraoperative steroid groups were significantly lower than in control group. The serum IL-6 levels in preoperative steroid group were lower than the serum levels in the intraoperative steroid group from the end of surgery to the third day after surgery. The CRP levels in steroids groups were also lower than in control group on the third day. There were no significant differences in the postoperative neutrophil count between the three groups. There was no postoperative infectious complication or suture failure.

CONCLUSIONS

This study shows that the preoperative administration of steroids modified the systemic inflammatory response caused by surgical trauma in patients with cervical laminoplasty.

Ketamine and peripheral inflammation

The old anesthetic ketamine has demonstrated interactions with the inflammatory response. This review intends to qualify the nature and the mechanism underlying this interaction. For this purpose, preclinical data will be presented starting with the initial works, and then, the probable mechanisms will be discussed. A summary of the most relevant clinical data will be presented. In conclusion, ketamine appears as a unique "homeostatic regulator" of the acute inflammatory reaction and the stress-induced immune disturbances. This is of some interest at a moment when the short- and long-term deleterious consequences of inadequate inflammatory reactions are increasingly reported. Large-scale studies showing improved patient's outcome are, however, required before to definitively assert the clinical reality of this positive effect.

Establishment of a coculture model for studying inflammation after pediatric cardiopulmonary bypass: from bench to bedside

Cardiopulmonary bypass (CPB) has been known to induce an inflammatory response that is influenced by various factors. Hypothermia is supposed to reduce inflammation after CPB. We developed an in vitro coculture model for CPB and compared the effects of hypothermia on the inflammatory response in the coculture model with results from a clinical prospective randomized trial. The coculture model consisted of endothelial cells and monocytes. Cells were stimulated with tumor necrosis factor (TNF)-α and exposed to deep hypothermia (20°C) or normothermia (37°C). In the clinical trial, 20 patients undergoing CPB for ventricular septum defect receive either normothermic (37°C) or mild hypothermic (32°C) CPB. We observed a significant interleukin (IL)-6 and IL-8 release in the coculture model 2 and 24 h after the experimental start. In the clinical trial, cytokines were significantly increased directly after weaning from CPB and remained elevated until 24 h. IL-8 and IL-6 secretions were similar in the hypothermic and normothermic group of the coculture model and the patients after 24 h. These results demonstrate that the inflammatory reaction observed in our coculture model is comparable with the cytokine increase in the blood of children undergoing CPB. Our coculture model could be useful for studies on the mechanisms of CPB-induced inflammation.

Perioperative use of statins in elective colectomy

BACKGROUND

Statins have many beneficial effects and may attenuate the proinflammatory and metabolic stress response to surgery and consequently reduce postoperative morbidity.

OBJECTIVE

This study investigated whether perioperative use of statins improved short-term outcomes after elective colectomy.

DESIGN

This study is a retrospective review of prospectively collected data.

SETTINGS AND PATIENTS

This study was conducted in consecutive patients undergoing elective colonic resection within an enhanced recovery program at a tertiary hospital (Manukau Surgery Centre, Middlemore Hospital, Auckland, New Zealand) from January 2005 to December 2010.

MAIN OUTCOME MEASURES

Complications, hospital stay, and readmissions were recorded for 30 days postoperatively. Postoperative functional recovery was measured by the use of the validated Surgical Recovery Score. Serum proinflammatory cytokines were measured on postoperative day 1.

RESULTS

There were 269 patients; 86 patients were on a statin perioperatively, whereas 183 patients had no statin. Members of the statin group were older (median age, 72 vs 69 years; p = 0.021), included more men (53% vs 40%; p = 0.049), and included a higher number of patients with an ASA score of 3 (55% vs 22%; p < 0.001). Patients on statin therapy had a significantly lower number of anastomotic leaks (1% vs 7%; p = 0.031). However, there was no significant difference in total complications or median hospital stay. The 2 groups had comparable functional recovery, and there was no significant difference in serum cytokine levels.

LIMITATIONS

This retrospective study did not analyze type, duration, or dose of statins given perioperatively.

CONCLUSION

Patients on perioperative statins had greater baseline perioperative risks compared with nonusers, but they achieved equivalent outcomes overall. Statin use was associated with reduced anastomotic leaks. Thus, perioperative statin use may reduce morbidity after elective colectomy, and this finding warrants further investigation.

Preoperative glucocorticoid use in major abdominal surgery: systematic review and meta-analysis of randomized trials

OBJECTIVE

To determine the clinical safety and efficacy of preoperative glucocorticoid (GC) administration in major abdominal surgery with regards to short term outcomes.

BACKGROUND

Previous randomized controlled trials (RCTs) in major abdominal surgery have displayed conflicting results regarding the short-term benefits of preoperative GC administration. Importantly, the safety of this intervention has not been conclusively determined.

METHODS

A systematic review and quantitative meta-analysis was conducted of all RCTs exploring preoperative GC administration in major abdominal surgery for the endpoints of complications, hospital length of stay (LOS) and serum IL-6 on postoperative day one. Subset analyses by procedure were planned "a priori."

RESULTS

Eleven RCTs of moderate quality, comprising 439 patients in total, were included in the final analysis. Preoperative GC use decreased complications (OR = 0.37; 95% CI, 0.21-0.64; P < 0.01), LOS (mean = 1.97 days; 95% CI, -3.33 to -0.61; P = 0.01), and serum IL-6 (mean: -55 pg/mL; 95% CI, -82.30 to -27.91; P < 0.01). Preoperative GCs decreased complications in hepatic resection (OR = 0.28; 95% CI, 0.14-0.55; P < 0.01) and mean LOS (mean LOS: -2.66; 95% CI, -5.01 to -0.32; P = 0.03). GCs reduced mean LOS in patients undergoing colorectal surgery (mean LOS: -0.98; 95% CI, -1.67 to -0.27; P = 0.01). There was no difference in complication rates (OR: 0.45; 95% CI, 0.16-1.32; P = 0.15) or anastomotic leaks specifically.

CONCLUSIONS

Preoperative administration of GCs decreases complications and LOS after major abdominal surgery as a likely consequence of attenuating the postsurgical inflammatory response. There is no evidence of increased complications in colorectal surgery.

The impact of the perioperative period on neurocognitive development, with a focus on pharmacological concerns

Mounting evidence from animal studies has implicated that all commonly used anaesthetics and sedatives may induce widespread neuronal cell death and result in long-term neurological abnormalities. These findings have led to serious questions regarding the safe use of these drugs in young children. In humans, recent findings from retrospective, epidemiological studies do not exclude the possibility of an association between surgery with anaesthesia early in life and subsequent learning abnormalities. These results have sparked discussions regarding the appropriate timing of paediatric surgery and the safe management of paediatric anaesthesia. However, important questions need to be addressed before findings from laboratory studies and retrospective clinical surveys can be used to guide clinical practice. This article summarises the currently available preclinical and clinical information regarding the impact of anaesthetics, sedatives, opioids, pain and stress, inflammation, hypoxia-ischaemia, co-morbidities and genetic predisposition on brain structure and long-term neurological function. Moreover, this article outlines the putative mechanisms of anaesthetic neurotoxicity, and the phenomenon's implications for clinical practice in this rapidly emerging field.

Preoperative and postoperative anesthetic and analgesic techniques for minimally invasive surgery of the spine

STUDY DESIGN

A review of methods to optimize anesthesia and analgesia for minimally invasive spine procedures.

OBJECTIVE

To provide information to surgeons and anesthesiologists of methods to provide optimal anesthesia and pain control for minimally invasive spine surgery with an emphasis on preoperative planning.

SUMMARY OF BACKGROUND DATA

Postoperative pain management in patients undergoing minimally invasive spine surgery is a challenge for the perioperative anesthesiologist. In addition to the incisional pain, trauma to deeper tissues, such as ligaments, muscles, intervertebral discs, and periosteum are reasons for significant pain. The increasing number of minimally invasive surgeries and the need for improved and rapid return of the patient of functionality have brought the perioperative anesthesiologist and the surgeon closer.

METHODS

We undertook a review of the literature currently available on anesthesia and analgesia for minimally invasive spine surgery with an emphasis on preoperative planning. A large number of reports of randomized controlled clinical trials with respect to perioperative anesthetic and postoperative pain management for minimally invasive spine surgery are reviewed and the applicability of some of the principles and protocols used for other types of minimally invasive surgical procedures are placed in the context of spine surgery.

RESULTS

It is important to understand and implement a multimodal analgesic therapy during a patient's preoperative visits. Perioperative multimodal analgesia with a fast-track anesthetic protocol is also important and provided in the manuscript. This protocol poses a challenge to the anesthesiologist with respect to neurophysiologic monitoring, which requires further study. The postoperative analgesic management should be a continuance of the multimodal analgesia provided before surgery. Some drugs are not appropriate for patients undergoing fusion surgery because of their effect on bone healing.

CONCLUSION

An optimal preoperative, perioperative, and postoperative anesthesia and analgesia protocol is important to best possible pain relief and rapid return to normal function. Communication between the anesthesiologist and spine surgeon is important to achieve a protocol with the best short- and long-term outcomes for the benefit of the patient.

Comparison of the Modulatory Effects of Four Different Fast-Track Anesthetic Techniques on the Inflammatory Response to Cardiac Surgery With Cardiopulmonary Bypass

OBJECTIVES

To test the hypothesis that the choice of anesthesia technique for coronary artery surgery influences the degree and magnitude of the subsequent inflammatory response and its consequences.

DESIGN

Prospective, randomized, comparative study.

SETTING

Major university teaching hospital.

PARTICIPANTS

Sixty patients undergoing elective surgery.

INTERVENTIONS

Patients were randomized into an alfentanil group, a high-dose remifentanil group, a low-dose remifentanil group, or a thoracic epidural group, in combination with a propofol target-controlled infusion. The study was blinded for the opioid, except in the epidural group. Tight control of perioperative hemodynamic parameters was maintained, and the postoperative management was strictly standardized. Bactericidal permeability-increasing protein as an indicator of the polymorphonuclear neutrophil response, interleukin-6 as an inducer of the acute-phase response, and lipopolysaccharide-binding protein and C-reactive protein as parameters of the acute phase response were determined at regular intervals. Ventilator dependency and analgesia were evaluated as clinical outcome measures.

MEASUREMENTS AND MAIN RESULTS

Interleukin-6 levels increased in all groups. Plasma levels in the epidural group were significantly higher at all time points than in the other groups. The increase in the plasma levels of bactericidal permeability-increasing protein, lipopolysaccharide-binding protein, and C-reactive protein showed the same pattern in all groups, and no significant differences among the 4 groups were observed.

CONCLUSIONS

Supplementation of a fast-track anesthetic technique with epidural analgesia preserves hemodynamic stability and is associated with faster extubation times (p = 0.003) and less postoperative pain (p = 0.045). Thoracic epidural analgesia was associated with significantly higher levels of IL-6 throughout the study period as compared with the total intravenous anesthesia groups. The exact clinical relevance of this finding remains unclear.

Prospective non-randomized evaluation of four mediators of the systemic response after extraperitoneal laparoscopic and open retropubic radical prostatectomy

OBJECTIVE

To report a prospective, controlled, non-randomized patient study to determine the systemic response to extraperitoneal laparoscopic (eLRP) and open retropubic radical prostatectomy (RRP).

PATIENTS AND METHODS

In all, 403 patients who had eLRP (163) or open RRP (240) were recruited; patients in both groups had similar preoperative staging. In addition to peri-operative variables (operative duration, complications, blood loss, transfusion rate, hospitalization, catheterization), oncological data (Gleason score, pathological stage, positive margins) were also compared. The extent of the systemic response to surgery-induced tissue trauma was measured in all patients, by assessing the levels of acute-phase markers C-reactive protein (CRP), serum amyloid A (SAA), interleukin-6 (IL-6) and IL-10 before, during and after RP.

RESULTS

The duration of surgery, transfusion rate, hospital stay and duration of catheterization were comparable with those in previous studies. There was an increase in IL-6, CRP and SAA but no change in IL-10, and no differences between eLRP and RRP over the entire period assessed.

CONCLUSION

The invasiveness of eLRP could not be substantiated objectively based on the variables measured in this study. The surgical trauma and associated invasiveness of both methods were equivalent.

Cytokines and C-Reactive Protein Production in Hip-Fracture-Operated Elderly Patients

BACKGROUND

The study aim was to determine the kinetics of serum pro- and anti-inflammatory cytokines and C-reactive protein (CRP) in hip-fracture patients over a month postfracture, and their relationship to postoperative (postop) complications and cognitive level.

METHODS

Forty-one elderly hip-fracture patients were prospectively followed. Serum was obtained during the first 10 hours postfracture and presurgery, 48-60 hours postop, 7 and 30 days postop, measuring CRP, interleukin-1beta (IL-1beta), IL-6, IL-8, tumor necrosis factor-alpha (TNF-alpha), IL-10, and IL-1 receptor antagonist (IL-1RA).

RESULTS

A significant increase was found postop for CRP, IL-6, TNF-alpha, IL-1RA (p <.001), IL-10 (p <.002), and IL-8 (p =.05). CRP kinetics curves were higher in patients with complications as a group, and in those suffering from infections, delirium, and cardiovascular complications (p <.05). IL-6 increase in patients with complications approached significance. Additional complications appeared in patients with impaired mental status (IMS) versus cognitively normal patients (p =.037). Higher kinetics curves in the IMS patients were found for CRP and IL-6 (p <.05). Analyzing the interaction effect of complications and IMS on CRP and cytokines production demonstrated that the increase in CRP was independently related to complications and IMS. IL-6, IL-8, and IL-10 were higher in IMS patients but not in patients with complications without IMS (p <.05).

CONCLUSIONS

Serum CRP and cytokines increased drastically in postop hip-fracture elderly patients. Only CRP significantly and independently increased in IMS patients and in patients with complications, whereas cytokines significantly increased only in IMS patients. This study raises questions about possible effects that cytokine generation, after hip-fracture repair, might have on cognition and complications.

Characterizing the Inflammatory Response to Cardiopulmonary Bypass in Children

Cardiopulmonary bypass is known to trigger a global inflammatory response. Age-dependent differences in the inflammatory response, the increased susceptibility to injury of immature organ systems, and the larger extracorporeal circuit to patient size ratio results in greater susceptibility of younger and smaller patients to the damaging effects of cardiopulmonary bypass. In this review the components of the inflammatory response to cardiopulmonary bypass are reviewed with special reference to the pediatric age group, including the age-specific impact on organ systems. In addition the current and evolving strategies to prevent, limit, and treat the inflammatory response to cardiopulmonary bypass in children are examined.

Impact of preoperative steroids administration on ischemia-reperfusion injury and systemic responses in liver surgery: a prospective randomized study

Hepatic injury secondary to warm ischemia-reperfusion (I/R) injury and alterations in haemostatic parameters are often unavoidable events after major hepatic resection. The release of inflammatory mediator is believed to play a significant role in the genesis of these events. It has been suggested that preoperative steroid administration may reduce I/R injury and improve several aspects of the surgical stress response. The aim of this prospective randomized study was to investigate the clinical benefits on I/R injury and systemic responses of preoperatively administered corticosteroids. Seventy-six patients undergoing liver resection were randomized either to a steroid group or to a control group. Patients in the steroid group received preoperatively 500 mg of methylprednisolone. Serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin, coagulation parameters, and inflammatory mediators, interleukin 6 and tumor necrosis factor alpha were compared between the 2 groups. Length of stay, and type and number of complications were recorded as well. Postoperative serum levels of ALT, AST, total bilirubin, and inflammatory cytokines were significantly lower in the steroid than in the control group at postoperative days 1 and 2. Changes in hemostatic parameters were also significantly attenuated in the steroid group. In conclusion, the incidence of postoperative complications in the steroid group tended to be significantly lower than the control group. It is of clinical interest that preoperative steroids administration before major surgery may reduce I/R injury, maintain coagulant/anticoagulant homeostasis, and reduce postoperative complications by modulating the inflammatory response.