Cerebral Protection by Lidocaine During Cardiac Operations: A Follow-Up Study

Anaesthesia-related cognitive dysfunction following cardiothoracic surgery in late middle-age and younger adults: A scoping review

BACKGROUND

The incidence of postoperative cognitive dysfunction (POCD) is notably high after cardiac surgery, ranging from 25% to 30%, and is associated with a lower quality of life, increased patient dependency, and heightened mortality. Anaesthesia during cardiothoracic surgery significantly contributes to the risk of POCD in older adults by adversely affecting the brain, including reductions in blood flow and oxygen levels.

AIM

This review aimed to evaluate factors associated with anaesthesia-related postoperative cognitive dysfunction (POCD) among adults younger than 65 years who underwent cardiothoracic surgeries.

STUDY DESIGN

A systematic keyword search, following the scoping review framework, was performed in the PubMed and CINAHL databases. Original English-language studies that included adults younger than 65 years and addressed cognitive function after surgery along with anaesthesia management were included. Retrospective studies, animal research and in vitro and in vivo studies were excluded.

RESULTS

Twenty-three articles were included (65.2% interventional studies). All studies lacked theoretical or conceptual frameworks. Ketamine's neuroprotective potential is questionable, and intravenous lidocaine may be considered a possible early agent for preventing POCD, but long-term effectiveness is uncertain. Compared to inhalational anaesthesia, total intravenous anaesthesia (TIVA) may be related to a decreased incidence of POCD. Variation in POCD assessment impacted the lack of homogeneity in obtained data. Moreover, the shorter-term timing of POCD evaluation such as in early days after surgery could be greatly influenced by medication and delirium.

CONCLUSION

Although strategies such as TIVA, the use of neuroprotective anaesthetics and comprehensive preoperative assessments are suggested to prevent POCD, this multifactorial phenomenon cannot be explicitly attributed solely to anaesthetics or anaesthesia-related techniques. Use of standardized, reliable and valid tools for POCD assessment is encouraged for cross-study comparison.

RELEVANCE TO CLINICAL PRACTICE

Nurses and certified nurse anaesthetists must be aware of risk factors for postoperative delirium and POCD so they can assess patients before and after surgery. Patients and caregivers need to be educated about cognitive changes after surgery and advised to report them to their health care provider if they occur.

The effect of intravenous lidocaine on postoperative cognitive dysfunction: a systematic review and meta-analysis

BACKGROUND

Postoperative cognitive dysfunction (POCD) has been reported as a significant complication in elderly patients. Various methods have been proposed for reducing the incidence and severity of POCD. Intravenous lidocaine administration has been reported in the literature to reduce POCD, but the effect of lidocaine remains controversial.

METHODS

We screened Medline, Embase, Cochrane Library, and China National Knowledge Infrastructure (up to April 2022) databases following a search strategy for intravenous lidocaine on POCD. We also screened related bibliographies on lidocaine for POCD. Ten articles comprising 1517 patients were selected and analyzed. We divided the postoperative follow-up period as follows: short term (<30 days), medium term (30-90 days), and long term (>90 days).

OUTCOMES

We found that lidocaine could attenuate the overall incidence of POCD, especially in the short term. There were no differences between lidocaine and placebo on the overall severity of POCD.

CONCLUSION

Lidocaine administered intravenously could attenuate the overall incidence of POCD and its severity in the short term.

Dual roles of anesthetics in postoperative cognitive dysfunction: Regulation of microglial activation through inflammatory signaling pathways

Postoperative cognitive dysfunction (POCD) is a prevalent clinical entity following surgery and is characterized by declined neurocognitive function. Neuroinflammation mediated by microglia is the essential mechanism of POCD. Anesthetics are thought to be a major contributor to the development of POCD, as they promote microglial activation and induce neuroinflammation. However, this claim remains controversial. Anesthetics can exert both anti- and pro-inflammatory effects by modulating microglial activation, suggesting that anesthetics may play dual roles in the pathogenesis of POCD. Here, we review the mechanisms by which the commonly used anesthetics regulate microglial activation via inflammatory signaling pathways, showing both anti- and pro-inflammatory properties of anesthetics, and indicating how perioperative administration of anesthetics might either relieve or worsen POCD development. The potential for anesthetics to enhance cognitive performance based on their anti-inflammatory properties is further discussed, emphasizing that the beneficial effects of anesthetics vary depending on dose, exposure time, and patients' characteristics. To minimize the incidence of POCD, we recommend considering these factors to select appropriate anesthetics.

Perioperative considerations in patients with chemotherapy-induced cognitive impairment: a narrative review

Patients with cancer may suffer from a decline in their cognitive function after various cancer therapies, including surgery, radiation, and chemotherapy, and in some cases, this decline in cognitive function persists even years after completion of treatment. Chemobrain or chemotherapy-induced cognitive impairment, a well-established clinical syndrome, has become an increasing concern as the number of successfully treated cancer patients has increased significantly. Chemotherapy-induced cognitive impairment can originate from direct neurotoxicity, neuroinflammation, and oxidative stress, resulting in alterations in grey matter volume, white matter integrity, and brain connectivity. Surgery has been associated with exacerbating the inflammatory response associated with chemotherapy and predisposes patients to develop postoperative cognitive dysfunction. As the proportion of patients living longer after these therapies increases, the magnitude of impact and growing concern of post-treatment cognitive dysfunction in these patients has also come to the fore. We review the clinical presentation, potential mechanisms, predisposing factors, diagnostic methods, neuropsychological testing, and imaging findings of chemotherapy-induced cognitive impairment and its intersection with postoperative cognitive dysfunction.

Prophylactic effect of intravenous lidocaine against cognitive deficit after cardiac surgery: A PRISMA-compliant meta-analysis and trial sequential analysis

BACKGROUND

This study aimed at providing an updated evidence of the association between intraoperative lidocaine and risk of postcardiac surgery cognitive deficit.

METHODS

Randomized clinical trials (RCTs) investigating effects of intravenous lidocaine against cognitive deficit in adults undergoing cardiac surgeries were retrieved from the EMBASE, MEDLINE, Google scholar, and Cochrane controlled trials register databases from inception till May 2021. Risk of cognitive deficit was the primary endpoint, while secondary endpoints were length of stay (LOS) in intensive care unit/hospital. Impact of individual studies and cumulative evidence reliability were evaluated with sensitivity analyses and trial sequential analysis, respectively.

RESULTS

Six RCTs involving 963 patients published from 1999 to 2019 were included. In early postoperative period (i.e., 2 weeks), the use of intravenous lidocaine (overall incidence = 14.8%) was associated with a lower risk of cognitive deficit compared to that with placebo (overall incidence = 33.1%) (relative risk = 0.49, 95% confidence interval: 0.32-0.75). However, sensitivity analysis and trial sequential analysis signified insufficient evidence to arrive at a firm conclusion. In the late postoperative period (i.e., 6-10 weeks), perioperative intravenous lidocaine (overall incidence = 37.9%) did not reduce the risk of cognitive deficit (relative risk = 0.99, 95% confidence interval: 0.84) compared to the placebo (overall incidence = 38.6%). Intravenous lidocaine was associated with a shortened LOS in intensive care unit/hospital with weak evidence.

CONCLUSION

Our results indicated a prophylactic effect of intravenous lidocaine against cognitive deficit only at the early postoperative period despite insufficient evidence. Further large-scale studies are warranted to assess its use for the prevention of cognitive deficit and enhancement of recovery (e.g., LOS).

Parasternal After Cardiac Surgery (PACS): a prospective, randomised, double-blinded, placebo-controlled trial study protocol for evaluating a continuous bilateral parasternal block with lidocaine after open cardiac surgery through sternotomy

BACKGROUND

Multimodal analgesia that provides optimal pain treatment with minimal side effects is important for optimal recovery after open cardiac surgery. Regional anaesthesia can be used to block noxious nerve signals. Because sternotomy causes considerable pain that lasts several days, a continuous nerve block is advantageous. Previous studies on continuous sternal wound infusion or parasternal blocks with long-acting local anaesthetics have shown mixed results. This study aims to determine whether a continuous bilateral parasternal block with lidocaine, which is a short-acting local anaesthetic that has a favourable safety/toxicity profile, results in effective analgesia. We hypothesise that a 72-hour continuous parasternal block with 0.5% lidocaine at a rate of 7 ml/hour on each side provides effective analgesia and reduces opioid requirement. We will evaluate whether recovery is enhanced.

METHODS

In a prospective, randomised, double-blinded manner, 45 patients will receive a continuous parasternal block with either 0.5% lidocaine or saline. The primary endpoint is cumulated intravenous morphine by patient-controlled analgesia at 72 hours. Secondary end-points include the following: (1) the cumulated numerical rating scale (NRS) score recorded three times daily at 72 hours; (2) the cumulated NRS score after two deep breaths three times daily at 72 hours; (3) the NRS score at rest and after two deep breaths at 2, 4, 8 and 12 weeks after surgery; (4) oxycodone requirement at 2, 4, 8 and 12 weeks after surgery; (5) Quality of Recovery-15 score preoperatively compared with that at 24, 48 and 72 hours, and at 2, 4, 8 and 12 weeks after surgery; (6) preoperative peak expiratory flow compared with postoperative daily values for 3 days; and (7) serum concentrations of interleukin-6 and lidocaine at 1, 24, 48 and 72 hours postoperatively compared with preoperative values.

DISCUSSION

Adequate analgesia is important for quality of care and vital to a rapid recovery after cardiac surgery. This study aims to determine whether a continuous parasternal block with a short-acting local anaesthetic improves analgesia and recovery after open cardiac procedures.

TRIAL REGISTRATION

The study was registered in the European Clinical Trials Database on 27/9/2019 (registration number: 2018-004672-35).

Efficacy of systemic lidocaine in postoperative delirium in elderly patients undergoing laparoscopic colorectal surgery: study protocol for a multicentre, prospective, double-blind, randomised, parallel-group, superiority, placebo-controlled trial

INTRODUCTION

Systemic lidocaine may reduce pain intensity and accelerate postoperative recovery. However, the efficacy of systemic lidocaine in cognitive function has not been established. This study protocol is designed to clarify the effectiveness of lidocaine in postoperative delirium (POD) in elderly patients scheduled for elective laparoscopic colorectal surgery.

METHODS AND ANALYSIS

This is a prospective, multicentre, randomised, double-blind, parallel-group, placebo-controlled trial. One thousand and twenty elderly patients will be randomly allocated in a ratio of 1:1 to receive either systemic lidocaine (a bolus of 1.5 mg/kg, followed by an infusion of 1.5 mg/kg/hour until the end of the surgery) or identical volumes and rates of 0.9% saline. The primary outcome measure is the prevalence of POD during the first 5 postoperative days. Secondary outcomes include emergence agitation, the area under the curve of the Numeric Rating Scale pain scores over 48 hours, postoperative 48-hour cumulative opioid consumption, postoperative nausea and vomiting (PONV), recovery of bowel function, quality of recovery, and patient satisfaction with postoperative analgesia.

ETHICS AND DISSEMINATION

The Ethical Committee of the Fujian Provincial Hospital approved the study protocol (ref: K2021-06-018). Other participating subcentres must also obtain ethics committee approval before the start of the study. We will obtain written informed consent from each patient before they are randomised. This study will be presented at scientific conferences and submitted to international journals.

TRIAL REGISTRATION NUMBER

ChiCTR2100050314.

Lidocaine represses the malignant behavior of lung carcinoma cells via the circ_PDZD8/miR-516b-5p/GOLT1A axis

Lung carcinoma is the most prevalent malignancy in adults. Lidocaine (Lido) has been confirmed to exert an anti-tumor role in many human cancers. However, the role and underlying mechanism of Lido in lung carcinoma remain poorly understood. Cell proliferation ability, migration, invasion, and apoptosis were measured by Colony formation, 5-ethynyl-2'-deoxyuridine (EdU), Cell Counting Kit-8 (CCK-8), transwell, and flow cytometry assays. Circ_PDZD8, microRNA-516b-5p (miR-516b-5p), and Golgi transport 1A (GOLT1A) levels were detected by real-time quantitative polymerase chain reaction (RT-qPCR). Protein levels of proliferating cell nuclear antigen (PCNA) and GOLT1A were examined by western blot assay. The binding relationship between miR-516b-5p and circ_PDZD8 or GOLT1A was predicted by circular RNA Interactome or Starbase 3.0 and then verified by a dual-luciferase reporter assay. The biological roles of circ_PDZD8 and Lido on lung carcinoma cell growth were examined by the xenograft tumor model in vivo. Lido suppressed proliferation, migration, invasion, and induced apoptosis in lung carcinoma cells. Circ_PDZD8 and GOLT1A were increased, miR-516b-5p was decreased in lung carcinoma tissues and cell lines. Their expression presented the opposite trend in Lido-triggered lung carcinoma cells. Circ_PDZD8 might overturn the repression of Lido on cell growth ability and metastasis in this tumor. Mechanically, circ_PDZD8 might regulate GOLT1A expression by sponging miR-516b-5p. Circ_PDZD8 weakened the anti-lung carcinoma effect of Lido in vivo. Circ_PDZD8 might mitigate the inhibitory effect of Lido on tumor cell malignancy by modulating the miR-516b-5p/GOLT1A axis, providing a novel insight for lung carcinoma treatment.

Targeted temperature management in cardiac surgery: a systematic review and meta-analysis on postoperative cognitive outcomes

BACKGROUND

Postoperative cognitive decline occurs commonly after cardiac surgery. The available literature is inconclusive on the role of intraoperative causal or protective factors.

METHODS

We systematically reviewed studies evaluating delayed neurocognitive recovery (DNR), postoperative neurocognitive disorder (NCD), stroke, and the mortality rates among patients undergoing hypothermic or normothermic cardiopulmonary bypass (CPB). We further performed a subgroup analysis for age, surgery type (coronary artery bypass grafting [CABG], valve surgery, or combined), and the mean arterial blood pressure (MAP) during CPB, and conducted a proportion meta-analysis after calculation of single proportions and confidence intervals (CIs).

RESULTS

We included a total of 58 studies with 9609 patients in our analysis. Among these, 1906 of 4010 patients (47.5%) had DNR, and 2071 of 7160 (28.9%) had postoperative NCD. Ninety of 4625 patients (2.0%) had a stroke, and 174 of 7589 (2.3%) died. There was no statistically significant relationship between the considered variables and DNR, NCD, stroke, and mortality. In the subgroup analysis comparing hypothermic with normothermic CPB, we found higher NCD rates after combined surgery; for normothermic CPB cases only, the rates of DNR and NCD were lower after combined surgery compared with CABG surgery. A MAP >70 mm Hg compared with MAP=50-70 mm Hg during CPB was associated with a lower rate of DNR.

CONCLUSIONS

Temperature, MAP during cardiopulmonary bypass age, and surgery type were not associated with neurocognitive disorders, stroke, and mortality in cardiac surgery. Normothermic cardiopulmonary bypass, particularly when performed with MAP >70 mm Hg, may reduce the risk of postoperative neurocognitive decline after cardiac surgery.

PROSPERO REGISTRATION NUMBER

CRD42019140844.

Protective effects on acute hypoxic-ischemic brain damage in mfat-1 transgenic mice by alleviating neuroinflammation

Acute hypoxic-ischemic brain damage (HIBD) mainly occurs in adults as a result of perioperative cardiac arrest and asphyxia. The benefits of n-3 polyunsaturated fatty acids (n-3 PUFAs) in maintaining brain growth and development are well documented. However, possible protective targets and underlying mechanisms of mfat-1 mice on HIBD require further investigation. The mfat-1 transgenic mice exhibited protective effects on HIBD, as indicated by reduced infarct range and improved neurobehavioral defects. RNA-seq analysis showed that multiple pathways and targets were involved in this process, with the anti-inflammatory pathway as the most significant. This study has shown for the first time that mfat-1 has protective effects on HIBD in mice. Activation of a G protein-coupled receptor 120 (GPR120)-related anti-inflammatory pathway may be associated with perioperative and postoperative complications, thus innovating clinical intervention strategy may potentially benefit patients with HIBD.

Pharmacological Agents That Prevent Postoperative Cognitive Dysfunction in Patients With General Anesthesia: A Network Meta-analysis

BACKGROUND

Postoperative cognitive dysfunction (POCD) is associated with prolonged hospital stays, increased mortality, and negative socioeconomic consequences. Dexmedetomidine, ketamine, dexamethasone, and lidocaine have previously been reported to be effective for preventing POCD.

STUDY QUESTION

In this network meta-analysis, we apply direct and indirect comparisons to rank these pharmacological agents in terms of their effect on POCD, through which we seek to provide evidence for future clinical medication.

DATA SOURCES

A comprehensive literature search of PubMed, EMBASE, the Cochrane Library, and Web of Science was conducted to identify randomized controlled trials that examined the effects of dexmedetomidine, ketamine, dexamethasone, or lidocaine on POCD induced by general anesthesia.

STUDY DESIGN

For eligible studies, 2 reviewers independently extracted data and assessed the respective risk of bias. Bayesian network meta-analysis was conducted using R-3.4.1 software. A total of 30 articles were included in this meta-analysis.

RESULTS

Direct comparison showed that dexmedetomidine [odds ratio (OR) = 0.42, 95% confidence interval (CI): 0.32-0.55] may decrease the incidence of POCD for noncardiac surgery; dexmedetomidine (OR = 0.08, 95% CI: 0.01-0.63) and ketamine (OR = 0.09, 95% CI: 0.02-0.32) were found to decrease POCD for cardiac surgery. The R-software ranking result for prevention of POCD was dexmedetomidine, lidocaine, ketamine, placebo, and dexamethasone, respectively, in noncardiac surgery, and dexmedetomidine, ketamine, lidocaine, placebo, and dexamethasone in cardiac surgery.

CONCLUSION

Dexmedetomidine exhibited obvious superiority to other agents for noncardiac surgery; dexmedetomidine and ketamine exhibited a significantly better performance than other agents for cardiac surgery. Dexamethasone did not show better efficacy than the placebo. However, more rigorously designed studies comprising larger sample sizes are needed to confirm our findings.

Intravenous Lidocaine Does Not Improve Neurologic Outcomes after Cardiac Surgery: A Randomized Controlled Trial

BACKGROUND

Cognitive decline after cardiac surgery occurs frequently and persists in a significant proportion of patients. Preclinical studies and human trials suggest that intravenous lidocaine may confer protection in the setting of neurologic injury. It was hypothesized that lidocaine administration would reduce cognitive decline after cardiac surgery compared to placebo.

METHODS

After institutional review board approval, 478 patients undergoing cardiac surgery were enrolled into this multicenter, prospective, randomized, double-blinded, placebo-controlled, parallel group trial. Subjects were randomized to lidocaine 1 mg/kg bolus after the induction of anesthesia followed by a continuous infusion (48 μg · kg · min for the first hour, 24 μg · kg · min for the second hour, and 10 μg · kg · min for the next 46 h) or saline with identical volume and rate changes to preserve blinding. Cognitive function was assessed preoperatively and at 6 weeks and 1 yr postoperatively using a standard neurocognitive test battery. The primary outcome was change in cognitive function between baseline and 6 weeks postoperatively, adjusting for age, years of education, baseline cognition, race, and procedure type.

RESULTS

Among the 420 allocated subjects who returned for 6-week follow-up (lidocaine: N = 211; placebo: N = 209), there was no difference in the continuous cognitive score change (adjusted mean difference [95% CI], 0.02 (-0.05, 0.08); P = 0.626). Cognitive deficit (greater than 1 SD decline in at least one cognitive domain) at 6 weeks occurred in 41% (87 of 211) in the lidocaine group versus 40% (83 of 209) in the placebo group (adjusted odds ratio [95% CI], 0.94 [0.63, 1.41]; P = 0.766). There were no differences in any quality of life outcomes between treatment groups. At the 1-yr follow-up, there continued to be no difference in cognitive score change, cognitive deficit, or quality of life.

CONCLUSIONS

Intravenous lidocaine administered during and after cardiac surgery did not reduce postoperative cognitive decline at 6 weeks.

Lidocaine inhibits proliferation and metastasis of lung cancer cell via regulation of miR-539/EGFR axis

Background: Despite the medical uses of lidocaine has been well-characterized, the study of lidocaine's pharmacological function other the anaesthetic effect was never stopped. This study designed to reveal the effect of lidocaine on the growth and metastasis of lung cancer in vitro. Methods: A549 and NCI-H1299 cells were treated by lidocaine for 24 h. miR-539 expression in cell was silenced by transfection with the specific inhibitor. The changes in cell growth and metastasis were determined using CCK-8 assay and western blot. Luciferase activity assay was performed to assay if EGFR was a target of miR-539. Western blot was used to test the activation of EGFR downstream signalling. Results: Lidocaine suppressed the viability, migration, and invasion of A549 and NCI-H1299 cells while induced apoptotic death. Lidocaine elevated the expression of miR-539. The anti-tumour properties of lidocaine towards A549 and NCI-H1299 cells were partially attenuated when miR-539 was silenced. EGFR was a target of miR-539. Lidocaine repressed the activation of ERK and PI3K/AKT pathways also via regulating miR-539. Conclusion: The anti-growth and anti-metastatic effects of lidocaine towards lung cancer cells. The anti-tumour properties of lidocaine may be partial via up-regulation of miR-539, which blocked EGFR signalling by directly binding with EGFR.

Neuroprotection against stroke and encephalopathy after cardiac surgery

Cerebral ischemia in the perioperative period is a major risk factor for stroke, encephalopathy, and cognitive decline after cardiothoracic surgery. After coronary artery bypass grafting, both stroke and encephalopathy can result in poor patient outcomes and increased mortality. Neuroprotection aims to lessen the severity and occurrence of further injury mediated by stroke and encephalopathy and to aid the recovery of conditions already present. Several pharmacological and non-pharmacological methods of neuroprotection have been investigated in experimental studies and in animal models, and, although some have shown effectiveness in protection of the central nervous system, for most, clinical research is lacking or did not show the expected results. This review summarizes the value and need for neuroprotection in the context of cardiothoracic surgery and examines the use and effectiveness of several agents and methods with an emphasis on clinical trials and clinically relevant neuroprotectants.

Effects of anesthesia on cerebral blood flow, metabolism, and neuroprotection

Administration of anesthetic agents fundamentally shifts the responsibility for maintenance of homeostasis from the patient and their intrinsic physiological regulatory mechanisms to the anesthesiologist. Continuous delivery of oxygen and nutrients to the brain is necessary to prevent irreversible injury and arises from a complex series of regulatory mechanisms that ensure uninterrupted cerebral blood flow. Our understanding of these regulatory mechanisms and the effects of anesthetics on them has been driven by the tireless work of pioneers in the field. It is of paramount importance that the anesthesiologist shares this understanding. Herein, we will review the physiological determinants of cerebral blood flow and how delivery of anesthesia impacts these processes.

Effects of local anesthetics on breast cancer cell viability and migration

Background

Breast cancer accounts for nearly a quarter of all cancers in women worldwide, and more than 90% of women diagnosed with breast cancer undergo mastectomy or breast-conserving surgery. Retrospective clinical studies have suggested that use of regional anesthesia leads to improved patient outcomes. Laboratory studies have reported that breast cancer cells are inhibited by some local anesthetics at millimolar concentration. Here, we present a comprehensive analysis of the effects of six common local anesthetics on two human breast cancer cell lines. We used concentrations ranging from those corresponding to plasma levels during regional block by local anesthetic (plasma concentration) to those corresponding to direct infiltration of local anesthetic.

Methods

Human breast cancer cell lines, MDA-MB-231 and MCF7, were incubated with each of six local anesthetics (lidocaine, mepivacaine, ropivacaine, bupivacaine, levobupivacaine, and chloroprocaine) (10 μM ~ 10 mM) for 6 to 72 h. Assays for cell viability, cytotoxicity, migration, and cell cycle were performed.

Results

High concentrations (> 1 mM) of local anesthetics applied to either MDA-MB-231 or MCF7 cells for 48 h significantly inhibited cell viability and induced cytotoxicity. At plasma concentrations (~ 10 μM) for 72 h, none of the local anesthetics affected cell viability or migration in either cell line. However, at 10 × plasma concentrations, 72-h exposure to bupivacaine, levobupivacaine or chloroprocaine inhibited the viability of MDA-MB-231 cells by > 40% (p < 0.001). Levobupivacaine also inhibited the viability of MCF7 cells by 50% (p < 0.001). None of the local anesthetics affected the viability of a non-cancerous breast cell line, MCF10A. MDA-MB-231 cell migration was inhibited by 10 × plasma concentrations of levobupivacaine, ropivacaine or chloroprocaine and MCF7 cell migration was inhibited by mepivacaine and levobupivacaine (p < 0.05). Cell cycle analysis showed that the local anesthetics arrest MDA-MB-231 cells in the S phase at both 1 × and 10 × plasma concentrations.

Conclusions

Local anesthetics at high concentrations significantly inhibited breast cancer cell survival. At 10 × plasma concentrations, the effect of local anesthetics on cancer cell viability and migration depended on the exposure time, specific local anesthetic, specific measurement endpoint and specific cell line.

Continuous intravenous perioperative lidocaine infusion for postoperative pain and recovery in adults

BACKGROUND

The management of postoperative pain and recovery is still unsatisfactory in a number of cases in clinical practice. Opioids used for postoperative analgesia are frequently associated with adverse effects, including nausea and constipation, preventing smooth postoperative recovery. Not all patients are suitable for, and benefit from, epidural analgesia that is used to improve postoperative recovery. The non-opioid, lidocaine, was investigated in several studies for its use in multimodal management strategies to reduce postoperative pain and enhance recovery. This review was published in 2015 and updated in January 2017.

OBJECTIVES

To assess the effects (benefits and risks) of perioperative intravenous (IV) lidocaine infusion compared to placebo/no treatment or compared to epidural analgesia on postoperative pain and recovery in adults undergoing various surgical procedures.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, and reference lists of articles in January 2017. We searched one trial registry contacted researchers in the field, and handsearched journals and congress proceedings. We updated this search in February 2018, but have not yet incorporated these results into the review.

SELECTION CRITERIA

We included randomized controlled trials comparing the effect of continuous perioperative IV lidocaine infusion either with placebo, or no treatment, or with thoracic epidural analgesia (TEA) in adults undergoing elective or urgent surgery under general anaesthesia. The IV lidocaine infusion must have been started intraoperatively, prior to incision, and continued at least until the end of surgery.

DATA COLLECTION AND ANALYSIS

We used Cochrane's standard methodological procedures. Our primary outcomes were: pain score at rest; gastrointestinal recovery and adverse events. Secondary outcomes included: postoperative nausea and postoperative opioid consumption. We used GRADE to assess the quality of evidence for each outcome.

MAIN RESULTS

We included 23 new trials in the update. In total, the review included 68 trials (4525 randomized participants). Two trials compared IV lidocaine with TEA. In all remaining trials, placebo or no treatment was used as a comparator. Trials involved participants undergoing open abdominal (22), laparoscopic abdominal (20), or various other surgical procedures (26). The application scheme of systemic lidocaine strongly varies between the studies related to both dose (1 mg/kg/h to 5 mg/kg/h) and termination of the infusion (from the end of surgery until several days after).The risk of bias was low with respect to selection bias (random sequence generation), performance bias, attrition bias, and detection bias in more than 50% of the included studies. For allocation concealment and selective reporting, the quality assessment yielded low risk of bias for only approximately 20% of the included studies.IV Lidocaine compared to placebo or no treatment We are uncertain whether IV lidocaine improves postoperative pain compared to placebo or no treatment at early time points (1 to 4 hours) (standardized mean difference (SMD) -0.50, 95% confidence interval (CI) -0.72 to -0.28; 29 studies, 1656 participants; very low-quality evidence) after surgery. Due to variation in the standard deviation (SD) in the studies, this would equate to an average pain reduction of between 0.37 cm and 2.48 cm on a 0 to 10 cm visual analogue scale . Assuming approximately 1 cm on a 0 to 10 cm pain scale is clinically meaningful, we ruled out a clinically relevant reduction in pain with lidocaine at intermediate (24 hours) (SMD -0.14, 95% CI -0.25 to -0.04; 33 studies, 1847 participants; moderate-quality evidence), and at late time points (48 hours) (SMD -0.11, 95% CI -0.25 to 0.04; 24 studies, 1404 participants; moderate-quality evidence). Due to variation in the SD in the studies, this would equate to an average pain reduction of between 0.10 cm to 0.48 cm at 24 hours and 0.08 cm to 0.42 cm at 48 hours. In contrast to the original review in 2015, we did not find any significant subgroup differences for different surgical procedures.We are uncertain whether lidocaine reduces the risk of ileus (risk ratio (RR) 0.37, 95% CI 0.15 to 0.87; 4 studies, 273 participants), time to first defaecation/bowel movement (mean difference (MD) -7.92 hours, 95% CI -12.71 to -3.13; 12 studies, 684 participants), risk of postoperative nausea (overall, i.e. 0 up to 72 hours) (RR 0.78, 95% CI 0.67 to 0.91; 35 studies, 1903 participants), and opioid consumption (overall) (MD -4.52 mg morphine equivalents , 95% CI -6.25 to -2.79; 40 studies, 2201 participants); quality of evidence was very low for all these outcomes.The effect of IV lidocaine on adverse effects compared to placebo treatment is uncertain, as only a small number of studies systematically analysed the occurrence of adverse effects (very low-quality evidence).IV Lidocaine compared to TEAThe effects of IV lidocaine compared with TEA are unclear (pain at 24 hours (MD 1.51, 95% CI -0.29 to 3.32; 2 studies, 102 participants), pain at 48 hours (MD 0.98, 95% CI -1.19 to 3.16; 2 studies, 102 participants), time to first bowel movement (MD -1.66, 95% CI -10.88 to 7.56; 2 studies, 102 participants); all very low-quality evidence). The risk for ileus and for postoperative nausea (overall) is also unclear, as only one small trial assessed these outcomes (very low-quality evidence). No trial assessed the outcomes, 'pain at early time points' and 'opioid consumption (overall)'. The effect of IV lidocaine on adverse effects compared to TEA is uncertain (very low-quality evidence).

AUTHORS' CONCLUSIONS

We are uncertain whether IV perioperative lidocaine, when compared to placebo or no treatment, has a beneficial impact on pain scores in the early postoperative phase, and on gastrointestinal recovery, postoperative nausea, and opioid consumption. The quality of evidence was limited due to inconsistency, imprecision, and study quality. Lidocaine probably has no clinically relevant effect on pain scores later than 24 hours. Few studies have systematically assessed the incidence of adverse effects. There is a lack of evidence about the effects of IV lidocaine compared with epidural anaesthesia in terms of the optimal dose and timing (including the duration) of the administration. We identified three ongoing studies, and 18 studies are awaiting classification; the results of the review may change when these studies are published and included in the review.

Neuroprotective Strategies in Repair and Replacement of the Aortic Arch

Aortic arch surgery is a technical challenge, and cerebral protection during distal anastomosis is a continued topic of controversy and discussion. The physiologic effects of hypothermic arrest and adjunctive cerebral perfusion have yet to be fully defined, and the optimal strategies are still undetermined. This review highlights the historical context, physiological rationale, and clinical efficacy of various neuroprotective strategies during arch operations.

Lidocaine dose-response effect on postoperative cognitive deficit: meta-analysis and meta-regression

INTRODUCTION

The true influence of the perioperative intravenous lidocaine on the development of postoperative cognitive deficit (POCD) in coronary artery bypass grafting (CABG) remains controversial. The principal aim is to undertake a meta-regression to determine whether moderator variables mediate the relationship between lidocaine and POCD. Areas covered: We searched the Web of Science, PubMed database, Scopus and the Cochrane Library database (up to June 2017) and systematically reviewed a list of retrieved articles. Our final review includes only randomized controlled trials (RCTs) that compared infusion of lidocaine and placebo during cardiopulmonary bypass (CPB). Mantel-Haenszel risk ratio (MH RR) and corresponding 95% confidence interval (CI) was used to report the overall effect and meta-regression analysis. A total of 688 patients in five RCTs were included. POCD occurred in 34% of all cases. Perioperative lidocaine reduces POCD (MH RR 0.702 (95% CI: 0.541-0.909). Younger age, male gender, longer CPB and higher concentration of lidocaine significantly mediate the relationship between lidocaine and POCD in favour of the neuroprotective effect of lidocaine. Expert commentary: The neuroprotective effect of lidocaine on POCD is consistent in spite of longer CPB time. A higher concentration of lidocaine strengthened the neuroprotective effect of lidocaine.

Post-Operative Cognitive Dysfunction: An exploration of the inflammatory hypothesis and novel therapies

Post-Operative Cognitive Dysfunction (POCD) is a highly prevalent condition with significant clinical, social and financial impacts for patients and their communities. The underlying pathophysiology is becoming increasingly understood, with the role of neuroinflammation and oxidative stress secondary to surgery and anaesthesia strongly implicated. This review aims to describe the putative mechanisms by which surgery-induced inflammation produces cognitive sequelae, with a focus on identifying potential novel therapies based upon their ability to modify these pathways.

Intraoperative care for aortic surgery using circulatory arrest

The total circulatory arrest (CA) is necessary to achieve optimal surgical conditions in certain aortic pathologies, especially in those affecting the ascending aorta and aortic arch. During this procedure it is necessary to protect all the organs of ischemia, especially those of the central nervous system and for this purpose several strategies have been developed. The first and most important protective method is systemic hypothermia. The degree of hypothermia and the route of application have been evolving and currently tend to use moderate hypothermia (MH) (20.1-28 °C) associated with unilateral or bilateral selective cerebral perfusion methods. In this way the neurological results are better, the interval of security is greater and the times of extracorporeal circulation are smaller. Even so, it is necessary to take into account that there is the possibility of ischemia in the lower part of the body, especially of the abdominal viscera and the spinal cord, therefore the time of circulatory stop should be limited and not to exceed 80 minutes. Evidence of possible neurological drug protection is very weak and only mannitol, magnesium, and statins can produce some benefit. Inhalational anesthetics and some intravenous seem to have advantages, but more studies would be needed to test their long-term benefit. Other important parameters to be monitored during these procedures are blood glucose, anemia and coagulation disorders and acid-base balance. The recommended monitoring is common in complex cardiovascular procedures and it is of special importance the neurological monitoring that can be performed with several techniques, although currently the most used are Bispectral Index (BIS) and Near-Infrared Spectroscopy (NIRS). It is also essential to monitor the temperature routinely at the nasopharyngeal and bladder level and it is important to control coagulation with rotational thromboelastometry (ROTEM).

Continuous Lidocaine Infusion as Adjunctive Analgesia in Intensive Care Unit Patients

Despite a paucity of data, the role of intravenous lidocaine (IVLI) as adjunctive analgesia in the intensive care unit (ICU) seems promising due to a low potential to contribute to respiratory depression. A retrospective chart review was conducted to evaluate the safety and effectiveness of IVLI for the treatment of pain in ICU patients with varying degrees of organ dysfunction from March 2014 to March 2016. The primary outcomes included the time to a ≥20% reduction in pain scores after the initiation of IVLI and the difference in opioid requirements as well as pain scores prior to and during IVLI therapy. Other variables included the presence of IVLI-related adverse events and the dosage and duration of IVLI. A total of 21 ICU patients were included from 2 different hospitals. The mean time to a ≥20% reduction in pain scores from the start of IVLI was 3.3 hours (SD = 2.2). The median morphine dose equivalents required during 6, 12, and 24 hours pre-IVLI were significantly higher compared to the same time periods after IVLI (18.3 vs 10 mg, P = .002; 41.8 vs 18.3 mg, P = .002; 93.5 vs 30.5 mg, P = .037). Neurological adverse effects of lidocaine were noted in 3 patients, but the effects were reversed on IVLI discontinuation. This report suggests that IVLI as an adjunctive agent in the treatment of acute pain may be a potential option in ICU patients who are refractory to opioids or those in whom opioid-induced respiratory depression is a concern.

Administration of lidocaine to prevent cognitive deficit in patients undergoing coronary artery bypass grafting and valve plasty: a systematic review and meta-analysis

INTRODUCTION

The administration of lidocaine to maintain cognitive function following coronary artery bypass grafting (CABG) and valve plasty is a controversial concept in terms of its effectiveness. We performed a systematic review to determine the effectiveness of treatment with lidocaine in preventing the occurrence of cognitive deficit after cardiac surgery. Area covered: To review the current literature on the subject, we searched the PubMed database and the Cochrane Library database (up to May 2015) and compiled a list of retrieved articles. Our final review includes only randomized controlled trials (RCTs) that compared lidocaine to a control (placebo) following CABG and valve plasty. Statistical analysis of the odds ratio (OR) and corresponding 95% confidence interval (CI) were used to determine the overall effectiveness of lidocaine for the prevention of cognitive deficit with both procedures. The Mantel-Haenszel method was used to pool data of the outcomes of cognitive deficit occurrence into fixed-effect model meta-analyses. Five RCTs were included in this study, with a total of 688 patients. Perioperative administration of lidocaine in patients undergoing cardiac surgery reduced occurrence of cognitive deficit (OR 0.583 [95% CI 0.438-0.777]; Z = -3.680; P = 0.00; I² = 52%). No significant difference in the early occurrence of cognitive deficit was revealed in patients after cardiac surgery (OR 0.909 [95% CI 0.600-1.376]; Z = -0.451; P = 0.652; I² = 11%). Expert commentary: Cognitive deficit associated with cardiac surgery is a common postoperative event. Lidocaine is contributed to a significantly reduced occurrence of cognitive deficit. Cognitive deficit management is recommended.

Lidocaine Did Not Reduce Neuropsychological-Cognitive Decline in Patients 6 Months After Supratentorial Tumor Surgery: A Randomized, Controlled Trial

: There is equivocal evidence examining cognitive improvement in response to lidocaine during cardiac surgery; however, no study has examined its effect on postoperative neuropsychological-cognitive decline after supratentorial tumor surgery.

METHODS

Ninety-four patients scheduled for supratentorial craniotomy were enrolled. Patients received either a dose of lidocaine (2%) via an intravenous bolus (1.5 mg/kg) after induction followed by an infusion at a rate of 2 mg/kg/h until the end of surgery (Lidocaine group) or the same volume of normal saline. The neuropsychological-cognitive decline was evaluated using the following tests: the Mini-Mental State Examination, the Information-Memory-Concentration test, the Hamilton Rating Scale for Depression, and the Hamilton Rating Scale for Anxiety. The cerebral oxygen extraction ratio and the difference in lactic acid levels between the bulb of the jugular vein and a peripheral artery were measured.

RESULTS

Eighty patients completed the neuropsychological tests, with 40 patients in each group. The incidence of postoperative decline at up to 6 months in the Lidocaine group was not significantly different than that in the Normal saline group. When the 2 cognitive tests were examined independent of the other tests, there was no difference between groups at 6 months. The cerebral oxygen extraction ratio was significantly lower in the Lidocaine group after surgery (P<0.05), and the arteriovenous difference of lactic acid was lower in the Lidocaine group (P<0.05).

CONCLUSIONS

Intraoperative infusion of lidocaine does not significantly decrease the incidence of postoperative neuropsychological-cognitive decline in patients 6 months after supratentorial tumor surgery.

Risk Factors Associated with Cognitive Decline after Cardiac Surgery: A Systematic Review

Modern day cardiac surgery evolved upon the advent of cardiopulmonary bypass machines (CPB) in the 1950s. Following this development, cardiac surgery in recent years has improved significantly. Despite such advances and the introduction of new technologies, neurological sequelae after cardiac surgery still exist. Ischaemic stroke, delirium, and cognitive impairment cause significant morbidity and mortality and unfortunately remain common complications. Postoperative cognitive decline (POCD) is believed to be associated with the presence of new ischaemic lesions originating from emboli entering the cerebral circulation during surgery. Cardiopulmonary bypass was thought to be the reason of POCD, but randomised controlled trials comparing with off-pump surgery show contradictory results. Attention has now turned to the growing evidence that perioperative risk factors, as well as patient-related risk factors, play an important role in early and late POCD. Clearly, identifying the mechanism of POCD is challenging. The purpose of this systematic review is to discuss the literature that has investigated patient and perioperative risk factors to better understand the magnitude of the risk factors associated with POCD after cardiac surgery.

Postoperative Cognitive Dysfunction: Minding the Gaps in Our Knowledge of a Common Postoperative Complication in the Elderly

Postoperative cognitive dysfunction (POCD) is a common complication associated with significant morbidity and mortality in elderly patients. There is much interest in and controversy about POCD, reflected partly in the increasing number of articles published on POCD recently. Recent work suggests surgery may also be associated with cognitive improvement in some patients, termed postoperative cognitive improvement (POCI). As the number of surgeries performed worldwide approaches 250 million per year, optimizing postoperative cognitive function and preventing/treating POCD are major public health issues. In this article, we review the literature on POCD and POCI, and discuss current research challenges in this area.

Continuous intravenous perioperative lidocaine infusion for postoperative pain and recovery

BACKGROUND

The management of postoperative pain and recovery is still unsatisfactory in clinical practice. Opioids used for postoperative analgesia are frequently associated with adverse effects including nausea and constipation. These adverse effects prevent smooth postoperative recovery. On the other hand not all patients may be suited to, and take benefit from, epidural analgesia used to enhance postoperative recovery. The non-opioid lidocaine was investigated in several studies for its use in multi-modal management strategies to reduce postoperative pain and enhance recovery.

OBJECTIVES

The aim of this review was to assess the effects (benefits and risks) of perioperative intravenous lidocaine infusion compared to placebo/no treatment or compared to epidural analgesia on postoperative pain and recovery in adults undergoing various surgical procedures.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, Issue 5 2014), MEDLINE (January 1966 to May 2014), EMBASE (1980 to May 2014), CINAHL (1982 to May 2014), and reference lists of articles. We searched the trial registry database ClinicalTrials.gov, contacted researchers in the field, and handsearched journals and congress proceedings. We did not apply any language restrictions.

SELECTION CRITERIA

We included randomized controlled trials comparing the effect of continuous perioperative intravenous lidocaine infusion either with placebo, or no treatment, or with epidural analgesia in adults undergoing elective or urgent surgery under general anaesthesia. The intravenous lidocaine infusion must have been started intraoperatively prior to incision and continued at least until the end of surgery.

DATA COLLECTION AND ANALYSIS

Trial quality was independently assessed by two authors according to the methodological procedures specified by the Cochrane Collaboration. Data were extracted by two independent authors. We collected trial data on postoperative pain, recovery of gastrointestinal function, length of hospital stay, postoperative nausea and vomiting (PONV), opioid consumption, patient satisfaction, surgical complication rates, and adverse effects of the intervention.

MAIN RESULTS

We included 45 trials involving 2802 participants. Two trials compared intravenous lidocaine versus epidural analgesia. In all the remaining trials placebo or no treatment was used as a comparator. Trials involved participants undergoing open abdominal (12), laparoscopic abdominal (13), or various other surgical procedures (20).The risk of bias was low with respect to selection bias (random sequence generation), performance bias, attrition bias, and detection bias in more than 50% of the included studies. For allocation concealment and selective reporting the quality assessment yielded low risk of bias for only approximately 20% of the included studies.We found evidence of effect for intravenous lidocaine on the reduction of postoperative pain (visual analogue scale, 0 to 10 cm) compared to placebo or no treatment at 'early time points (one to four hours)' (mean difference (MD) -0.84 cm, 95% confidence interval (CI) -1.10 to -0.59; low-quality evidence) and at 'intermediate time points (24 hours)' (MD -0.34 cm, 95% CI -0.57 to -0.11; low-quality evidence) after surgery. However, no evidence of effect was found for lidocaine to reduce pain at 'late time points (48 hours)' (MD -0.22 cm, 95% CI -0.47 to 0.03; low-quality evidence). Pain reduction was most obvious at 'early time points' in participants undergoing laparoscopic abdominal surgery (MD -1.14, 95% CI -1.51 to -0.78; low-quality evidence) and open abdominal surgery (MD -0.72, 95% CI -0.96 to -0.47; moderate-quality evidence). No evidence of effect was found for lidocaine to reduce pain in participants undergoing all other surgeries (MD -0.30, 95% CI -0.89 to 0.28; low-quality evidence). Quality of evidence is limited due to inconsistency and indirectness (small trial sizes).Evidence of effect was found for lidocaine on gastrointestinal recovery regarding the reduction of the time to first flatus (MD -5.49 hours, 95% CI -7.97 to -3.00; low-quality evidence), time to first bowel movement (MD -6.12 hours, 95% CI -7.36 to -4.89; low-quality evidence), and the risk of paralytic ileus (risk ratio (RR) 0.38, 95% CI 0.15 to 0.99; low-quality evidence). However, no evidence of effect was found for lidocaine on shortening the time to first defaecation (MD -9.52 hours, 95% CI -23.24 to 4.19; very low-quality evidence).Furthermore, we found evidence of positive effects for lidocaine administration on secondary outcomes such as reduction of length of hospital stay, postoperative nausea, intraoperative and postoperative opioid requirements. There was limited data on the effect of IV lidocaine on adverse effects (e.g. death, arrhythmias, other heart rate disorders or signs of lidocaine toxicity) compared to placebo treatment as only a limited number of studies systematically analysed the occurrence of adverse effects of the lidocaine intervention.The comparison of intravenous lidocaine versus epidural analgesia revealed no evidence of effect for lidocaine on relevant outcomes. However, the results have to be considered with caution due to imprecision of the effect estimates.

AUTHORS' CONCLUSIONS

There is low to moderate evidence that this intervention, when compared to placebo, has an impact on pain scores, especially in the early postoperative phase, and on postoperative nausea. There is limited evidence that this has further impact on other relevant clinical outcomes, such as gastrointestinal recovery, length of hospital stay, and opioid requirements. So far there is a scarcity of studies that have systematically assessed the incidence of adverse effects; the optimal dose; timing (including the duration of the administration); and the effects when compared with epidural anaesthesia.

[Update on the pharmacology and effects of local anesthetics]

Local anesthetics (LA) are broadly used in all disciplines and it could be considered that relatively little is reflected on the mechanisms of action of this old substance group. However, several molecular mechanisms of LAs mediating wanted and unwanted effects remain to be explored. Furthermore, the number of indications for application of LAs seems to be expanding. The local anesthetic effect of LAs is primarily mediated by a potent inhibition of voltage-gated sodium channels. However, this effect is due to much more than the interaction of LAs with one single molecule. Most recent studies indicated that the development of selective local anesthetics might be possible and LAs also interact with several other membrane molecules. Although the relevance of these effects is still unclear, they might play a role in systemic analgesia, tissue protection and anti-inflammatory effects of LA. The therapeutic index of systemically applied LA is very narrow. Systemic application is formally not permitted because the impending systemic toxicity is still a life-threatening complication. Although the cardiac and central nervous toxicity at least partly result from an unselective block of neuronal and cardiac sodium channels, preclinical studies suggest the involvement of several mechanisms. A local LA toxicity is less clinically impressive; however, all LAs induce a significant tissue toxicity for which the underlying mechanisms have been partly identified. This review reports on recent findings on mechanisms and on the clinical relevance of some LA-induced effects which are of relevance for anesthesiological activities.

Complex assessment of the incidence and risk factors of delirium in a large cohort of cardiac surgery patients: a single-center 6-year experience

BACKGROUND

Previous reports provided inconsistent data on the occurrence of postoperative delirium and emphasized its considerable impact on outcome. This study sought to evaluate the incidence and predictors of delirium, together with its relation to cerebral ischemia in a large cohort of cardiac surgery patients in a tertiary high-volume center.

METHODS AND RESULTS

Consecutive patients (n = 8792) were prospectively enrolled from 2003 to 2008. Exclusion criteria were history of psychiatric disorders, use of psychoactive drugs, alcohol abuse, and data incompleteness. Finally, 5781 patients were analyzed in terms of 100 perioperative patient-specific and treatment variables. The incidence of postoperative delirium (DSM IV criteria) was 4.1% and it coexisted with cerebral ischemia in 1.1% of patients. In bivariate analysis, 49 variables were significantly linked to postoperative delirium. Multivariate analysis confirmed that delirium was independently associated with postoperative stroke (logistic odds ratio (logOR) = 2.862, P = 0.004), any blood transfusions (logOR = 4.178, P < 0.0001), age > 65 years (logOR = 2.417, P = 0.002), carotid artery stenosis (logOR = 2.15, P = 0.01), urgent/emergent surgery (logOR = 1.982, P = 0.02), fasting glucose level, intraoperative oxygen partial pressure fluctuations, and hematocrit. Area under ROC curve for the model was 0.8933.

CONCLUSIONS

Early identification of nonpsychiatric perioperative determinants of delirium facilitates its diagnosis and might help develop preventive strategies to improve long-term outcome after cardiac surgery procedures.

Effect of Perioperative Intravenous Lidocaine Administration on Pain, Opioid Consumption, and Quality of Life after Complex Spine Surgery

Background:

The authors tested the primary hypothesis that perioperative IV lidocaine administration during spine surgery (and in the postanesthesia care unit for no more than 8 h) decreases pain and/or opioid requirements in the initial 48 postoperative hours. Secondary outcomes included major complications, postoperative nausea and vomiting, duration of hospitalization, and quality of life.

Methods:

One hundred sixteen adults having complex spine surgery were randomly assigned to perioperative IV lidocaine (2 mg·kg−1·h−1) or placebo during surgery and in the postanesthesia care unit. Pain was evaluated with a verbal response scale. Quality of life at 1 and 3 months was assessed using the Acute Short-form (SF) 12 health survey. The authors initially evaluated multivariable bidirectional noninferiority on both outcomes; superiority on either outcome was then evaluated only if noninferiority was established.

Results:

Lidocaine was significantly superior to placebo on mean verbal response scale pain scores (P &lt; 0.001; adjusted mean [95% CI] of 4.4 [4.2-4.7] and 5.3 [5.0-5.5] points, respectively) and significantly noninferior on mean morphine equivalent dosage (P = 0.011; 55 [36-84] and 74 [49-111] mg, respectively). Postoperative nausea and vomiting and the duration of hospitalization did not differ significantly. Patients given lidocaine had slightly fewer 30-day complications than patients given placebo (odds ratio [95% CI] of 0.91 [0.84–1.00]; P = 0.049). Patients given lidocaine had significantly greater SF-12 physical composite scores than placebo at 1 (38 [31–47] vs. 33 [27–42]; P = 0.002) and 3 (39 [31–49] vs. 34 [28–44]; P = 0.04) months, postoperatively.

Conclusion:

IV lidocaine significantly improves postoperative pain after complex spine surgery.

Cognitive deficit in first-time coronary artery bypass graft patients: a randomized clinical trial of lidocaine versus procaine hydrochloride

Introduction:

Cognitive dysfunction increasingly has been recognized as a complication after cardiac surgery. Different methods have been considered for the reduction of cognitive dysfunction after cardiac surgery. One of these methods is by using lidocaine during surgery. The aim of this study was to determine the effects of adding lidocaine to the cardioplegia solution on cognitive impairment after coronary artery surgery.

Design and methods:

In a prospective, randomized, double-blind trial, 110 patients aged between 20-70 years, scheduled for elective CABG surgery using cardiopulmonary bypass, were recruited into the study. They were randomized into two groups who received either cardioplegia solution containing lidocaine 2 mg/kg or procaine hydrochloride 5 mg/kg. The neurocognitive test used in this study was the Mini Mental State Examination (MMSE) or Folstein test. The test was done on the day before and 10 days and 2 months after the operation.

Results:

In the procaine group, the total score after 10 days decreased significantly compared to the preoperative score (mean difference 0.68; 95% CI: 0.20 to 1.17, p=0.006). Comparison between mean differences after 10 and 60 days of operation between the lidocaine and procaine groups were statistically significant, p-value 0.017 and 0.013, respectively. There was no cognitive impairment in the lidocaine group, but, in the procaine group, four patients (7.7%) after 10 days and one patient (1.9%) after both 10 and 60 days had cognitive impairment, p=0.051.

Conclusions:

Administration of lidocaine compared to that of procaine through the cardioplegia solution had a better effect on cognitive function after coronary artery bypass graft surgery.

Brain damage in cardiac surgery patients

Neuropsychological disorders and brain injury are still a serious problem in cardiac surgery patients. Owing to multifactorial mechanism of brain injury during extracorporeal circulation, the effective and safe protection is extremely difficult. Despite several studies, the ideal neuroprotective treatment has not been found. Based on literature we analysed the main mechanisms of brain injury and new methods of brain protection.

Can postoperative cognitive dysfunction be avoided?

Postoperative cognitive dysfunction (POCD) refers to a postoperative decline in cognitive function compared with preoperative cognitive function. Diagnosis requires pre- and postoperative testing, the latter of which is usually performed both 7 days and 3 months postoperatively. Although several risk factors for POCD have been described, age is the only consistently reported risk factor. Postoperative cognitive dysfunction is often transient. It may last several months, and is associated with leaving the labor market prematurely and increased mortality. As the pathophysiology of POCD is still a matter of debate and is likely to be multifactorial, there are no widely accepted prophylactic and therapeutic interventions. In this article, we discuss POCD's definition, risk factors, long-term significance, and pathophysiology. We also present data on prophylactic interventions that have been investigated in clinical trials.

Intravenous antiarrhythmic doses of lidocaine increase the survival rate of CA1 neurons and improve cognitive outcome after transient global cerebral ischemia in rats

Brain ischemia is often a consequence of cardiac or neurologic surgery. Prophylactic pharmacological neuroprotection would be beneficial for patients undergoing surgery to reduce brain damage due to ischemia. We examined the effects of two antiarrhythmic doses of lidocaine (2 or 4 mg/kg) on rats in a model of transient global cerebral ischemia. The occlusion of both common carotid arteries combined with hypotension for 10 min induced neuronal loss in the CA1 region of the hippocampus (18±12 vs. 31±4 neurons/200 μm linear distance of the cell body layer, X±SD; P<0.01). Lidocaine (4 mg/kg) 30 min before, during and 60 min after ischemia increased dorsal hippocampal CA1 neuronal survival 4 weeks after global cerebral ischemia (30±9 vs. 18±12 neurons/200 μm; P<0.01). There was no significant cell loss after 10 min of ischemia in the CA3 region, the dentate region or the amygdalae; these regions were less sensitive than the CA1 region to ischemic damage. Lidocaine not only increased hippocampal CA1 neuronal survival, but also preserved cognitive function associated with the CA1 region. Using an active place avoidance task, there were fewer entrances into an avoidance zone, defined by relevant distal room-bound cues, in the lidocaine groups. The untreated ischemic group had an average, over the nine sessions, of 21±12 (X±SD) entrances into the avoidance zone per session; the 4 mg/kg lidocaine group had 7±8 entrances (P<0.05 vs. untreated ischemic) and the non-ischemic control group 7±5 entrances (P<0.01 vs. untreated ischemic). Thus, a clinical antiarrhythmic dose of lidocaine increased the number of surviving CA1 pyramidal neurons and preserved cognitive function; this indicates that lidocaine is a good candidate for clinical brain protection.

Minocycline may be useful to prevent/treat postoperative cognitive decline in elderly patients

Postoperative cognitive dysfunction (POCD) is reported to occur frequently after all types especially cardiac surgery in elderly patients. It can be short-term or long-term and some cases even develop into Alzheimer's disease (AD). Although multi-risk factors associated with POCD have been identified, the etiology and pathophysiological mechanisms of this surgical complication remain elusive. Therefore, developing strategies for preventing or treating POCD is still challenging. However, increasing evidence suggests that central and systemic inflammation triggered by surgery likely plays a fundamental role in POCD developing and progression. Minocycline, a tetracycline derivative with anti-inflammatory properties, has been shown to be effective in treating neuroinflammatory related conditions or neurodegenerative diseases such as AD, Parkinson's disease, Huntington's disease. Considering that inflammation may be a potential factor of POCD and minocycline is effective in improving cognitive dysfunction induced by inflammation, we hypothesize that minocycline may be useful to treat/prevent the POCD development after surgery in elderly patients.

Decompression illness

Decompression illness is caused by intravascular or extravascular bubbles that are formed as a result of reduction in environmental pressure (decompression). The term covers both arterial gas embolism, in which alveolar gas or venous gas emboli (via cardiac shunts or via pulmonary vessels) are introduced into the arterial circulation, and decompression sickness, which is caused by in-situ bubble formation from dissolved inert gas. Both syndromes can occur in divers, compressed air workers, aviators, and astronauts, but arterial gas embolism also arises from iatrogenic causes unrelated to decompression. Risk of decompression illness is affected by immersion, exercise, and heat or cold. Manifestations range from itching and minor pain to neurological symptoms, cardiac collapse, and death. First-aid treatment is 100% oxygen and definitive treatment is recompression to increased pressure, breathing 100% oxygen. Adjunctive treatment, including fluid administration and prophylaxis against venous thromboembolism in paralysed patients, is also recommended. Treatment is, in most cases, effective although residual deficits can remain in serious cases, even after several recompressions.

Measurement of post-operative cognitive dysfunction after cardiac surgery: a systematic review

Post-operative cognitive dysfunction (POCD) is a decline in cognitive function from pre-operative levels, which has been frequently described after cardiac surgery. The purpose of this study was to examine the variability in the measurement and definitions for POCD using the framework of a 1995 Consensus Statement on measurement of POCD. Electronic medical literature databases were searched for the intersection of the search terms 'thoracic surgery' and 'cognition, dementia, and neuropsychological test.' Abstracts were reviewed independently by two reviewers. English articles with >50 participants published since 1995 that performed pre-operative and post-operative psychometric testing in patients undergoing cardiac surgery were reviewed. Data relevant to the measurement and definition of POCD were abstracted and compared with the recommendations of the Consensus Statement. Sixty-two studies of POCD in patients undergoing cardiac surgery were identified. Of these studies, the recommended neuropsychological tests were carried out in less than half of the studies. The cognitive domains measured most frequently were attention (n=56; 93%) and memory (n=57; 95%); motor skills were measured less frequently (n=36; 60%). Additionally, less than half of the studies examined anxiety and depression, performed neurological exam, or accounted for learning. Four definitions of POCD emerged: per cent decline (n=15), standard deviation decline (n=14), factor analysis (n=13), and analysis of performance on individual tests (n=12). There is marked variability in the measurement and definition of POCD. This heterogeneity may impede progress by reducing the ability to compare studies on the causes and treatment of POCD.

Recent Publications on Medications and Pharmacy

Hospital Pharmacy presents this feature to keep pharmacists abreast of new publications in the medical/pharmacy literature. Articles of interest regarding a broad scope of topics are abstracted monthly. Suggestions or comments may be addressed to Jacyntha Sterling, Drug Information Specialist at Saint Francis Hospital, 6161 S Yale Ave, Tulsa, OK 74136 or e-mail: jasterling@saintfrancis.com .