Effects Of Anesthetic Agents Research Articles

Anesthesia-induced Lymphatic Dysfunction.

General anesthetics adversely alters the distribution of infused fluid between the plasma compartment and the extravascular space. This maldistribution occurs largely from the effects of anesthetic agents on lymphatic pumping, which can be demonstrated by macroscopic fluid kinetics studies in awake versus anesthetized patients. The magnitude of this effect can be appreciated as follows: a 30% reduction in lymph flow may result in a fivefold increase of fluid-induced volume expansion of the interstitial space relative to plasma volume. Anesthesia-induced lymphatic dysfunction is a key factor why anesthetized patients require greater than expected fluid administration than can be accounted for by blood loss, urine output, and insensible losses. Anesthesia also blunts the transvascular refill response to bleeding, an important compensatory mechanism during hemorrhagic hypovolemia, in part through lymphatic inhibition. Last, this study addresses how catecholamines and hypertonic and hyperoncotic fluids may mobilize interstitial fluid to mitigate anesthesia-induced lymphatic dysfunction.

Comparison of Two Different Doses of Nalbuphine With Isobaric Ropivacaine in Patients Undergoing Lower Segment Cesarean Section Under Subarachnoid Block: A Randomized Controlled Trial.

Obstetric analgesia and anesthesia is a challenge in itself. It requires an understanding of the physiological changes during pregnancy and labor and the effect of anesthetic agents on the fetus and newborn. Because neuraxial techniques provide superior analgesia and materno-fetal benefits, their use have increased significantly over the past three decades or so. A combination of local anesthetics like ropivacaine with opioids like nalbuphine has been shown to have additive beneficial effects in subarachnoid block (SAB) in lower segment cesarean section (LSCS). However, the optimal dose combination of ropivacaine and nalbuphine to maximize their benefits and minimize side effects remains to be established. Our study has compared the clinical efficacy and safety of 0.75% isobaric ropivacaine (15 mg) with two different doses of nalbuphine (0.4 mg and 0.6 mg) when given intrathecally for LSCS in terms of quality of sensory and motor blocks, hemodynamic parameters, duration of effective analgesia, Apgar score in newborn, and associated side effects. In this prospective, randomized, double-blind study, a total of 69 parturients between the age of 20-45 years, belonging to American Society of Anesthesiologists (ASA) grade I and II, undergoing cesarean section under SAB were evaluated. Patients were randomly allocated into three groups of 23 each by using the draw-of-lots technique. The patient and the observer were kept blinded as to which dose of drug (intrathecal) was being given to the patient. Patients in Group A received 0.75% isobaric ropivacaine 15 mg (2 ml) + 0.3 ml normal saline; patients in Group B received 0.75% isobaric ropivacaine 15 mg (2 ml) + 0.4 mg of nalbuphine (0.2 ml) + 0.1 ml normal saline; patients in Group C received 0.75% isobaric ropivacaine 15 mg (2 ml) + 0.6 mg of nalbuphine (0.3 ml). The total volume of drug solution in all three groups was 2.3 ml. We found that the time to onset of sensory block was shortest in Group A (5.87±1.290 minutes) followed by Group C (6.00±1.087 minutes) and Group B (6.17±1.696 minutes); time to two-segment regression of sensory block was longest in Group C (101.74±8.996 minutes) followed by Group B (85.87±15.348 minutes) and Group A (65.00±7.071 minutes); duration of effective analgesia was longest in Group C (206.09±18.766 minutes) followed by Group B (183.91±15.880 minutes) and Group A (121.74±11.833 minutes); and time from SAB to complete regression of motor block was longest in Group C (216.52±15.553 minutes) followed by Group B (203.48±20.138 minutes) and Group A (174.78±14.731 minutes). Side effectswere comparable among all three groups. The optimal dose combination in SAB for cesarean section was 15 mg of 0.75% isobaric ropivacaine + 0.6 mg nalbuphine, with minimal side effects.

Pediatric neuroanesthesia experiences: A single center retrospective cohort study

Background/Aim: Pediatric neuroanesthesia is a special field that requires significant experience and infrastructure because of anatomical, neurological, and pharmacological differences in the pediatric patient population. Although technological improvements provide more effective and safer neuroanesthesiological management, the principles of neuroanesthesia, neurocognitive development, and the effects of anesthetic agents on central nervous system development are well-known. The majority of pediatric neuroanesthesia articles in the literature are reviews; however, retrospective/prospective case series and controlled research are limited. In this retrospective cohort study, we aimed to contribute to the existing literature by reviewing and analyzing our single-center 10-year experiences and results addressing pediatric neuroanesthesia management. Methods: After ethical committee approval, anesthetic and surgical reports from 1165 pediatric neurosurgical cases over ten years were collected. Demographic data, intra-operative vascular management, anesthesia techniques, airway management, patient positions, analgesia methods, and complications were evaluated in this retrospective cohort study. The available surgical intervention, patient positions, intra-operative neuromonitorization (IONM), and intra-operative magnetic resonance imaging (IOMR) records were also analyzed. Results: Six-hundred forty-six (55.4%) girls and 519 (44.5%) boys were included in the study. The median age was 60 (0–216) months. Cranial interventions were performed in 842 (72.3%) patients, and spinal interventions were performed in 323 (27.7%) patients. Patients’ American Society of Anesthesiologists (ASA) physical scales grouped as I, II, III, and IV were 718 (61.6%), 360 (30.9%), 82 (7%), and 5 (0.4%), respectively. Sevoflurane (40.3%), propofol (37.2%), and sodium thiopental (2.5%) were used for anesthetic induction. Neuromuscular block was performed with rocuronium (56.7%) and atracurium (14.4%). Neuromuscular blocking agents were not used in 337 patients (28.9%). A blood transfusion was required in 120 patients (10.3%), and 40% of these patients underwent surgery for craniosynostosis. Two-hundred twenty-two (19.1%) were monitored with IONM, and IOMR was carried out in 124 (10.6%) of the cases. The anesthesia-related complication rate was 5.15% (60 patients). Conclusion: Although pediatric neurosurgical interventions involve high risks, they are becoming increasingly common in our daily practice. Neuroanesthesiologists should know the procedures, techniques, and advances for safe and effective management of pediatric neurosurgical cases. We think that these data may be helpful as a guide for the anesthetic management of pediatric neurosurgical cases.

Updates in Prevention of Surgical Site Infection: Comment.

Long et al.1 provided a well-written and accessible review of new ideas in the field of surgical site infection prevention. Within their discussion of the patient’s microbiome, the authors touch on the potential for interactions between the patient microbiome and anesthetic agents administered perioperatively. Although they accurately identify the immunosuppressive potential of volatile anesthetics and intravenous opioids, we think that it is important to note that there exist other agents capable of producing and maintaining general anesthesia. Medications like ketamine and propofol are immunomodulatory in different ways, and thus their use may also impact the development of surgical site infections.Long et al.1 cite two mouse model articles where exposure to volatile anesthetics was associated with a decrease in intestinal microbiome diversity.2,3 In contrast, Guo et al.,4 using a rat model, looked at the effect of a continuous infusion of propofol during a 3-h period on the intestinal microbiome and found little change in the diversity of the intestinal microbiome after exposure to propofol. Similarly, Gerb et al.5 looked at the effects on the intestinal microbiome of mice after 10 daily exposures to a bolus dose of ketamine that rendered the mice unconscious for approximately 15 to 30 min per ketamine exposure and also found little change in the diversity of the intestinal microbiome.No definitive evidence exists to recommend one type of anesthetic over another. Given the minimal impact on the intestinal microbiome, it might be tempting to conclude that replacing volatile anesthetics with agents such as propofol and ketamine might decrease the incidence of surgical site infection. But there is also evidence to the contrary. For example, Visvabharathy et al.6 looked at susceptibility to infection due to exogenous bacteremia using Listeria and Staphylococcus aureus in mice receiving intravenous propofol compared to mice receiving intravenous ketamine with xylazine and found that propofol increased susceptibility to infection. In a research letter, Liu et al.7 looked at the intestinal microbiome in 21 patients undergoing nephrectomy with propofol alone compared to sevoflurane alone compared to propofol and sevoflurane combined and found that the mixed anesthetic7 was associated with the fewest perturbations.Clearly it remains premature to advocate for a total intravenous technique in the absence of more clinically robust data. Further research in animal models and in humans is needed to try and elucidate not only if there is an optimal anesthetic agent for prevention of surgical site infection, but also what the combined effects of multiple anesthetics, as routinely administered when patients present for surgery, have on the patient’s susceptibility to infection after surgery.Surgical site infections are a multidisciplinary problem. Once more data are available, it may turn out that the effects of anesthetic agents are small and of minor importance in patients with normal immune systems. But the selection of anesthetic agents is one aspect we have almost complete control over; we should be making every effort to maximize the ability of the patient’s immune system to combat infection.The authors declare no competing interests.

The effect of anesthetic agents used in oocyte collection on intracytoplasmic sperm injection results in patients treated for infertility due to male factor

The effect of anesthetic agents used in oocyte collection on intracytoplasmic sperm injection results in patients treated for infertility due to male factor

The Effect of Anesthetic Agent and Mean Arterial Pressure on Functional Outcome After General Anesthesia for Endovascular Thrombectomy.

The optimal general anesthetic (GA) technique for stroke patients undergoing endovascular thrombectomy (ET) is unclear. We compared favorable outcomes and mortality in patients receiving propofol or volatile GA during ET and assessed associations between mean arterial pressure (MAP) and outcome. Ninety-three patients with anterior circulation stroke who received propofol or volatile GA during ET between February 2015 and February 2018 were included in this retrospective study. Ninety-day modified Rankin scores were compared and mortality was adjusted for intravenous thrombolysis and diabetes. We performed ordinal logistic regression analyses containing MAP time/exposure thresholds. There was no difference in the rate of favorable outcome (modified Rankin scores 0-2) in the volatile and propofol groups (48.8% vs. 55.8%, respectively; P =0.5). Ninety-day mortality was lower in patients receiving propofol (11.5%) than in those receiving volatile GA (29.3%) (odds ratio, 0.32; 95% confidence interval, 0.11 to 0.94; P =0.03); this mortality benefit was greater in patients that did not receive intravenous thrombolysis before ET (odds ratio for survival, 6; 95% confidence interval, 1.13 to 31.74). There was no difference in MAP between groups and a (nonsignificant) trend towards the benefit of MAP <90mmHg but not <70mmHg. Favorable outcome rates were similar in stroke patients receiving propofol or volatile GA during ET. Propofol was associated with lower mortality, an effect magnified in patients that did not receive intravenous thrombolysis. MAP time/exposure thresholds were associated with outcome but independent of the anesthetic agent. Our data suggest that a difference in outcome related to an anesthetic agent may exist; this hypothesis needs to be tested in a prospective study.

Effects of Anesthetic Agents on Blood Brain Barrier Integrity: A Systematic Review.

The blood brain barrier (BBB) is a highly selective permeable barrier that separates the blood and the central nervous system. Anesthesia is an integral part of surgery, and there is little known about the impact of anesthetics on the BBB. Therefore, it is imperative to explore reversible or modifiable variables such as anesthetic agents that influence BBB integrity. We aimed to synthesize the literature pertaining to the various effects of anesthetics on the BBB. MEDLINE, Embase, and Cochrane were searched from inception up to September 2022. A total of 14 articles met inclusion into the review. The articles included nine randomized control studies (64.3%) and five quasi-experimental studies (35.7%). Twelve studies used volatile anesthetics, one study used fentanyl intravenously, and one study used pentobarbital or ketamine intraperitoneally. BBB structural deficits following the administration of an anesthetic agent included ultrastructural deficits, decreases in tight junctions, and decreases in BBB components. BBB functional deficits included permeability increases following exposure to volatile anesthetics. However, two studies found decreased permeability after fentanyl, pentobarbital, or ketamine exposure. Moreover, the impact of anesthetics on the BBB seems to be related to the duration of exposure. Notably, study findings also suggest that changes following anesthetic exposure demonstrate some reversibility over the short-term. Overall, our systematic review highlights interesting findings pertaining to the impact of anesthetic agents on BBB integrity in previously healthy models. These findings and mechanisms should inspire future work to aid practitioners and healthcare teams potentially better care for patients.

Anaesthetic Management of a Patient with Multiple Acetyl CoA Dehydrogenase Deficiency: A Case Report

Multiple acetyl CoA dehydrogenase deficiency is a rare autosomal recessive disorder of amino acid, fatty acid, and choline metabolism. It is a mitochondrial disorder with defective electron transfer flavoproteins or electron transfer flavoprotein dehydrogenases. They are vital for β-oxidation of fatty acids, an essential fuel for skeletal and cardiac muscles. It is also an important source of energy during starvation for the brain. Acute deterioration of these patients can occur during stressful periods like starvation, surgery, infection, and exercise. The anaesthetic management is a challenge with special emphasis on minimizing starvation, ensuring hydration and glucose supplementation, and considering the various effects of anaesthetic agents on the mitochondrial function. The anaesthetic management of a patient with multiple acetyl CoA dehydrogenase scheduled for modified radical mastectomy is described. General anaesthesia can be administered safely in these patients with special emphasis on hydration, glucose supplementation, avoidance of stressors, and monitoring of metabolic status.

Comparison of the Effect of Anesthetic Agents on Blood Levels of Parathyroid Hormone and Ionized Calcium: A Prospective Randomized Controlled Trial.

The aim of this randomized control trial is to compare the effect of anesthetic agents on blood levels of parathyroid hormone and ionized calcium. 77 American Society of Anesthesiologists I-II patients who would undergo laparoscopic cholecystectomy were enrolled into this prospective study and randomized into 3 groups with sealed envelope technique as Group S: sevoflurane, Group D: desflurane, and Group TIVA: total intravenous anesthesia. The first blood sample was used to check the baseline blood levels of parathyroid hormone and ionized calcium. In Group S or D, maintenance of anesthesia was being performed with 1 MAC (minimum alveolar concentration) sevoflurane or desflurane, respectively, while in Group TIVA, it was performed with 150 mcg/kg/min propofol and 1 mcg/kg/min remifentanil IV infusions. At the 30th minute of anesthesia and at the 1st hour of end of anesthesia, 2nd and 3rd blood samples, respectively, were used to check the blood levels of PTH and Ca. During perioperative period, hemodynamic parameters were also noted. Blood levels of parathyroid hormone at the 30th min after anesthesia were found to be significantly different between groups (P=0,01). The PTH level at the 30th min after anesthesia was found significantly higher in Group S than that of Groups D and TIVA (P=0.005 and P=0.001, respectively). Blood levels of ionized calcium at 30th min after anesthesia were found significantly different between groups (P=0,048). It was found significantly higher in Group TIVA than that in Group S (P=0.024). Desflurane seems to be the best agent for parathyroidectomy procedures. Future research studies are needed to be conducted to reach out more correct and valuable outcomes.

The physiologically difficult airway: an emerging concept.

The physiologically difficult airway is one in which physiologic alterations in the patient increase the risk for cardiorespiratory and other complications during tracheal intubation and transition to positive pressure ventilation. This review will summarize the recent literature around the emerging concept of the physiologically difficult airway, describe its relevance and various patient types in which this entity is observed. Physiologic derangements during airway management occur due acute illness, pre-existing disease, effects of anesthetic agents, and positive pressure ventilation. These derangements are especially recognized in critically ill patients, but can also occur in otherwise healthy patients including obese, pregnant and pediatric patients who have certain physiological alterations. Critically ill patients may have a physiologically difficult airway due to the presence of acute respiratory failure, hypoxemia, hypotension, severe metabolic acidosis, right ventricular failure, intracranial hypertension, and risk of aspiration of gastric contents during tracheal intubation. Understanding the physiological alterations and the risks involved in patients with a physiologically difficult airway is necessary to optimize the physiology and adopt strategies to avoid complications during tracheal intubation. Further research will help us better understand the optimal strategies to improve outcomes in these patients.

The effect of propofol-based anesthesia versus low dose propofol with less than half MAC sevoflurane on intraoperative trans-cranial motor evoked potential during spine surgeries: Ratios rather than values

ABSTRACT Background Transcranial motor evoked potentials (TcMEP) were proved to be useful during complicated spinal surgeries to prevent iatrogenic complications. The effect of anesthetic agents was comprehensively discussed in literature. We investigated a new balanced anesthetic protocol using propofol and sevoflurane in addition to continuous fentanyl infusion in which we compared values and ratios of amplitudes and latencies of TcMEP waves at different time point. Materials and Methods A total of 60 patients underwent spinal surgeries were randomly allocated into two groups who received either 75–100 µg/kg/min propofol ( P group) or 25 ug/kg/min propofol and 0.2% below corrected-to-age- half MAC of sevoflurane ( BA group). TcMEP was recorded before positioning (R1), after positioning (R2), and after skin incision (R3). R2/R1 and R3/R2 ratios were calculated. Modified Aldrete Score was recorded on discharge from PACU. Results Fluids infused and urine output were significantly increased in P group (p˂0.001). HR and MAP were significantly lower in P group (p˂0.001), but CVP was lower in P group at R1 and R2 (p = 0.019, 0.037). TcMEP was recorded from Vastus lateralis (VL) and Deltoid(D) muscles, which showed a significant lower amplitude in P group at different time points (p˂0.05) without significance in latencies. While when ratios were compared (L2/L1 and L3/L2), it showed significant differences (P˂0.001 and 0.041, respectively). Aldrete score was significantly higher in BA group. Conclusion Balanced regimen using propofol and sevoflurane resulted in a comparable TcMEP recording, hemodynamic stability and a better recovery from anesthesia during spinal surgeries.

Breast Cancer and Anaesthesia: Genetic Influence.

Breast cancer is the leading cause of mortality in women. It is a heterogeneous disease with a high degree of inter-subject variability even in patients with the same type of tumor, with individualized medicine having acquired significant relevance in this field. The clinical and morphological heterogeneity of the different types of breast tumors has led to a diversity of staging and classification systems. Thus, these tumors show wide variability in genetic expression and prognostic biomarkers. Surgical treatment is essential in the management of these patients. However, the perioperative period has been found to significantly influence survival and cancer recurrence. There is growing interest in the pro-tumoral effect of different anaesthetic and analgesic agents used intraoperatively and their relationship with metastatic progression. There is cumulative evidence of the influence of anaesthetic techniques on the physiopathological mechanisms of survival and growth of the residual neoplastic cells released during surgery. Prospective randomized clinical trials are needed to obtain quality evidence on the relationship between cancer and anaesthesia. This document summarizes the evidence currently available about the effects of the anaesthetic agents and techniques used in primary cancer surgery and long-term oncologic outcomes, and the biomolecular mechanisms involved in their interaction.

Anaesthesia for head trauma patients

There are many reasons anaesthetising a patient with head trauma may be required. These include for diagnostic imaging, surgery, or it may be required in severe cases to control the patient's ventilation. Many anaesthetic agents cause changes to the blood flow to the brain and therefore may cause further detriment to the patient. Thus, the veterinary nurse assisting the veterinary surgeon with these cases requires a thorough understanding of the physiology of head trauma and the effects of anaesthetic agents on cerebral blood flow, intracranial pressure and the cardiac and respiratory systems, as well as possible neuroprotective benefits that can be gained from the use of some agents.

Conscious rat PET imaging with soft immobilization for quantitation of brain functions: comprehensive assessment of anesthesia effects on cerebral blood flow and metabolism

BackgroundAnimal brain functions evaluated by in vivo imaging under anesthesia can be affected by anesthetic agents, resulting in incorrect assessment of physiological brain function. We therefore performed dynamic positron emission tomography (PET) imaging of conscious rats using recently reported soft immobilization to validate the efficacy of the immobilization for brain function assessments. We also determined the effects of six anesthetic agents—a mixed anesthetic agent (MMB), ketamine + xylazine (KX), chloral hydrate (Chloral), pentobarbital (PTB), propofol (PF), and isoflurane (IFL)—on brain function by comparison with conscious rats.ResultsThe immobilization enabled 45-min dynamic [18F]FDG-PET acquisition with arterial blood sampling using conscious rats without the use of special techniques or invasive surgery. The spatial resolution and quantitativity of [18F]FDG-PET were not significantly lower for conscious rats than for anesthetized rats. While MMB, Chloral, PTB, and PF showed ubiquitous reduction in the cerebral metabolic rates of glucose (CMRglu) in brain regions, KX and IFL showed higher reductions in cerebellum and interbrain, and cerebellum, respectively. Cerebral blood flow (CBF) was reduced by MMB, KX, PTB, and PF; increased by IFL; and unaltered by Chloral. The magnitude of decrease in CMRglu and CBF for MMB were not larger than for other five anesthetic agents, although blood glucose levels and body temperature can be easily affected by MMB.ConclusionThe six anesthetic agents induced various effects on CMRglu and CBF. The immobilization technique presented here is a promising tool for noninvasive brain functional imaging using conscious rats to avoid the effects of anesthetic agents.

Effects of Propofol versus Sevoflurane on Postoperative Pain and Neuroendocrine Stress Response in Oocyte Pickup Patients.

Background Pain aggravates the autonomic response to stress and raises neuroendocrine stress hormone levels. We compared the effects of propofol and sevoflurane on postoperative pain and neuroendocrine stress hormones. A prospective, randomized, and controlled trial was conducted with 60 patients. Methods We randomly allocated patients to groups P (remifentanil/propofol, n = 30) and S (remifentanil/sevoflurane, n = 30). Preoperative blood samples were taken to measure serum adrenocorticotropic hormone (ACTH), corticotropin-releasing hormone (CRH), glucagon, cortisol, aldosterone, and prostaglandin E2 (PGE2) levels. Intraoperatively and postoperatively, clinical parameters were monitored at different time points. The hormone levels were again measured in the follicular fluid and blood postoperatively. Result Demographic data were similar. The preoperative serum aldosterone levels were significantly higher in group P (p=0.001). Preoperative and postoperative serum ACTH, glucagon, cortisol, and PGE2 levels were significantly different in group P (p=0.009, p=0.004, p=0.029, and p=0.002); serum ACTH, glucagon, and PGE2 levels increased while serum cortisol levels decreased postoperatively. In group S, serum CRH and aldosterone levels, both increased in the postoperative period compared to the preoperative (p=0.001, p=0.006). Postoperatively, glucagon and PGE2 levels were both higher in group P than group S (p=0.019, p=0.015). In postoperative follicular fluid, glucagon and PGE2 levels were higher in group P, while cortisol levels were higher in group S (p=0.001, p=0.007, and p=0.001). Conclusion The effects of anesthetic agents were different. In group P, in the preoperative and postoperative evaluation, ACTH, glucagon, and PGE2 increased postoperatively, while cortisol decreased. In group S, aldosterone and CRH increased postoperatively. Glucagon and PG E2 were higher in group P than S, postoperatively.

Anesthetic technique and cancer surgery outcomes

Surgery remains integral to treating solid cancers. However, the surgical stress response, characterized by physiologic perturbation of the adrenergic, inflammatory, and immune systems, may promote procancerous pathways. Anesthetic technique per se may attenuate/enhance these pathways and thereby could be implicated in long-term cancer outcomes. To date, clinical studies have predominantly been retrospective and underpowered and, thus limit meaningful conclusions. More recently, prospective studies of regional anesthesia for breast and colorectal cancer surgery have failed to demonstrate long-term cancer outcome benefit. However, based on the consistent observation of protumorigenic effects of surgical stress and that of volatile anesthesia in preclinical studies, supported by in vivo models of tumor progression and metastasis, we await robust prospective clinical studies exploring the role of propofol-based total intravenous anesthesia (cf. inhalational volatiles). Additionally, anti-adrenergic/anti-inflammatory adjuncts, such as lidocaine, nonsteroidal anti-inflammatory drugs and the anti-adrenergic propranolol warrant ongoing research. The biologic perturbation of the perioperative period, compounded by the effects of anesthetic agents, renders patients with cancer particularly vulnerable to enhanced viability of minimal residual disease, with long-term outcome consequences. However, low level and often conflicting clinical evidence equipoise currently exists with regards to optimal oncoanesthesia techniques. Large, prospective, randomized control trials are urgently needed to inform evidence-based clinical practice guidelines.

Effects of anesthetic agents on inflammation in Caco-2, HK-2 and HepG2 cells.

Anesthetic agents are often used in surgical procedures to relieve pain in patients with traumatic injuries. Several anesthetic agents can cause immunosuppression by suppressing the secretion of immune factors such as cytokines. However, the effects of different anesthetic agents on inflammation are not completely understood. In the present study, three cell lines, Caco-2, HK-2 and HepG2, were treated with five anesthetic agents, including sodium barbiturate, midazolam, etomidate, ketamine and propofol, to investigate the effects of different anesthetic agents on inflammation in in vitro models. The expression levels of inflammatory genes, including NF-κB and its downstream cytokines, were detected via reverse transcription-quantitative PCR. The results indicated that anesthetic agents, including sodium barbiturate, ketamine and propofol, but not midazolam and etomidate, exerted significant inhibitory effects on NF-κB expression in the three different cell lines. Sodium barbiturate, ketamine and propofol also decreased the expression levels of the NF-κB downstream cytokines, including IL-1β and IL-18. Moreover, sodium barbiturate, ketamine and propofol reduced the effect of TNF-α on inflammatory activity in the three cell lines. The results of the present study may provide novel insight into the effects of anesthetic agents on inflammation and may aid with selecting the most appropriate anesthetic agent in surgical procedures.

Anesthetics affect peripheral venous pressure waveforms and the cross-talk with arterial pressure

Analysis of peripheral venous pressure (PVP) waveforms is a novel method of monitoring intravascular volume. Two pediatric cohorts were studied to test the effect of anesthetic agents on the PVP waveform and cross-talk between peripheral veins and arteries: (1) dehydration setting in a pyloromyotomy using the infused anesthetic propofol and (2) hemorrhage setting during elective surgery for craniosynostosis with the inhaled anesthetic isoflurane. PVP waveforms were collected from 39 patients that received propofol and 9 that received isoflurane. A multiple analysis of variance test determined if anesthetics influence the PVP waveform. A prediction system was built using k-nearest neighbor (k-NN) to distinguish between: (1) PVP waveforms with and without propofol and (2) different minimum alveolar concentration (MAC) groups of isoflurane. 52 porcine, 5 propofol, and 7 isoflurane subjects were used to determine the cross-talk between veins and arteries at the heart and respiratory rate frequency during: (a) during and after bleeding with constant anesthesia, (b) before and after propofol, and (c) at each MAC value. PVP waveforms are influenced by anesthetics, determined by MANOVA: p value < 0.01, η2 = 0.478 for hypovolemic, and η2 = 0.388 for euvolemic conditions. The k-NN prediction models had 82% and 77% accuracy for detecting propofol and MAC, respectively. The cross-talk relationship at each stage was: (a) ρ = 0.95, (b) ρ = 0.96, and (c) could not be evaluated using this cohort. Future research should consider anesthetic agents when analyzing PVP waveforms developing future clinical monitoring technology that uses PVP.

Systematic Review: Anesthetic Protocols and Management as Confounders in Rodent Blood Oxygen Level Dependent Functional Magnetic Resonance Imaging (BOLD fMRI)-Part B: Effects of Anesthetic Agents, Doses and Timing.

Simple SummaryTo understand brain function in rats and mice functional magnetic resonance imaging of the brain is used. With this type of “brain scan” regional changes in blood flow and oxygen consumption are measured as an indirect surrogate for activity of brain regions. Animals are often anesthetized for the experiments to prevent stress and blurred images due to movement. However, anesthesia may alter the measurements, as blood flow within the brain is differently affected by different anesthetics, and anesthetics also directly affect brain function. Consequently, results obtained under one anesthetic protocol may not be comparable with those obtained under another, and/or not representative for awake animals and humans. We have systematically searched the existing literature for studies analyzing the effects of different anesthesia methods or studies that compared anesthetized and awake animals. Most studies reported that anesthetic agents, doses and timing had an effect on functional magnetic resonance imaging results. To obtain results which promote our understanding of brain function, it is therefore essential that a standard for anesthetic protocols for functional magnetic resonance is defined and their impact is well characterized.In rodent models the use of functional magnetic resonance imaging (fMRI) under anesthesia is common. The anesthetic protocol might influence fMRI readouts either directly or via changes in physiological parameters. As long as those factors cannot be objectively quantified, the scientific validity of fMRI in rodents is impaired. In the present systematic review, literature analyzing in rats and mice the influence of anesthesia regimes and concurrent physiological functions on blood oxygen level dependent (BOLD) fMRI results was investigated. Studies from four databases that were searched were selected following pre-defined criteria. Two separate articles publish the results; the herewith presented article includes the analyses of 83 studies. Most studies found differences in BOLD fMRI readouts with different anesthesia drugs and dose rates, time points of imaging or when awake status was compared to anesthetized animals. To obtain scientifically valid, reproducible results from rodent fMRI studies, stable levels of anesthesia with agents suitable for the model under investigation as well as known and objectively quantifiable effects on readouts are, thus, mandatory. Further studies should establish dose ranges for standardized anesthetic protocols and determine time windows for imaging during which influence of anesthesia on readout is objectively quantifiable.

Fetal monitoring in neurosurgery: An essential paradigm?

Neurosurgical procedures during pregnancy are not uncommon, and anesthetic management of these patients are complicated by the physiologic changes of pregnancy, effects of anesthetic agents on fetus, and a need for vigilance to prevent a possibility of fetal demise. The value of intraoperative fetal heart rate (FHR) monitoring though controversial, is immense, and with various modalities available to choose from, necessary interventions could be made before fetal viability is jeopardized. We report the utility of intraoperative FHR monitoring using ultrasonography in case of a 32-year-old, 28 weeks, pregnant female, G4P(1)A2, posted for bifrontal craniotomy and excision of meningioma with subfalcine herniation.