General Anesthetic Research Articles

The Safety Profile of General and Local Anaesthetic Agents: Data Collected during 20 Years of Spontaneous Reporting Activities in the Campania Region (Southern Italy).

Background: General and local anaesthetics are widely used during surgery. These drugs have peculiar safety profiles, being commonly associated with mild and reversible local adverse drug reactions (ADRs), but also with more severe and systemic ADRs, including respiratory and cardiovascular depression and anaphylaxis. Methods and Objectives: We carried out a descriptive analysis of Individual Case Safety Reports (ICSRs) sent to the Campania Regional Centre of Pharmacovigilance (Southern Italy) from 2001 to 2021 that reported general or local anaesthetics as suspected drugs, with the aim of describing their overall characteristics, focussing on the ADRs’ seriousness and distribution by System Organ Class (SOC) and Preferred Term (PT). Results: A total of 110 ICSRs documenting general or local anaesthetics were sent to the Italian pharmacovigilance database during 20 years of spontaneous reporting activities in the Campania region. ADRs mainly occurred in patients with a median age of 48 years and in a slightly higher percentage of men. ADRs were more commonly classified as not serious and had a favourable outcome. In terms of ADRs’ distribution by SOC and PT, both general and local anaesthetics were associated with general and cutaneous disorders, with common ADRs that included lack of efficacy, rash, and erythema. In addition, general anaesthetics were associated with the occurrence of respiratory ADRs, while local anaesthetics were associated with the occurrence of nervous ADRs. Conclusion: Even though a limited number of ICSRs documenting anaesthetics-induced ADRs were retrieved from the Italian spontaneous reporting database in the Campania region, we believe that the continuous monitoring of these drugs is highly recommended, especially among the frail population.

Bioelectric activity monitoring of the hippocampal complex: action of inhalation anesthetics as a functional sample

Monitoring of the bioelectric activity of the hippocampal complex is performed according to the indications of patients with pharmacoresistant mesial temporal lobe epilepsy, who are indicated for surgical removal of the epileptic focus. The work was aimed at comparing the dynamics of the amplitude-frequency parameters of the bioelectrical activity of the hippocampal complex under the action of general anesthetics by comparing the parameters recorded before surgery and intraoperatively. The study included 8 patients with mesial temporal lobe epilepsy who, within the framework of pre-surgical planning, underwent invasive monitoring of the bioelectrical activity of the cortex and hippocampal com- plex, and then underwent surgical resection of the epileptic focus under general anesthesia with sevoflurane. Registration of 12 hippocampal tracks was carried out in dynamics: during extraoperative and intraoperative neurophysiological monitoring. In the state of calm wakefulness, the pattern of bioelectric activity of the hippocampal complex without structural changes was formed mainly by the activity of the alpha and theta frequency ranges. Under general anesthesia with sevoflurane, a slow-wave delta-range activity was recorded on the intraoperative ES- ubCoG. When the hippocampal complex was involved in the epileptic system, its activity in the state of passive wakefulness was represented by the slow-wave frequency range. Under the conditions of inhalation anesthesia with sevoflurane, the proportion of delta activity significantly decreased, and a state of dysrhythmia was observed without a clear dominance of activity in any range.

Off-Label Use of Ketamine: A Challenging Drug Treatment Delivery Model With an Inherently Unfavorable Risk-Benefit Profile.

Off-Label Use of Ketamine: A Challenging Drug Treatment Delivery Model With an Inherently Unfavorable Risk-Benefit Profile.

Parental Views on Minimally Invasive Dentistry versus General Anaesthesia Extractions of Children's Compromised First Permanent Molars: An Exploratory Qualitative Study.

The current standard of care for first permanent molars (FPMs) requiring extraction is removal of these teeth between the chronological ages of eight to ten years, as per UK guidelines.1 This often involves a general anaesthetic (GA) with surgical admission to hospital. This study explores parental views on minimally invasive (MI) techniques as an alternative to the UK current standard of care for extractions of FPMs deemed to require removal between the chronological ages of eight to ten years. A qualitative investigation, using semi-structured interviews was conducted with parents/carers of children attending a teaching hospital for extraction of compromised FPMs under GA. Thematic framework analysis was used to present the findings. The consolidated criteria for reporting qualitative research (COREQ) were used as a guide to ensure quality. The main themes emerging were: participants' surprise at how poor the prognosis was for their child's FPMs; acceptance that care was beyond the scope of primary care; willingness by some to undergo GA again; requests for information about the guarantee of success of MI treatment; concerns about the residual black staining from silver diamine fluoride (SDF); and acceptance of extraction spaces because of potential future failure of MI. This exploratory qualitative study has shown that, while extraction of compromised FPMs under GA is accepted by most parents/carers, there appears to be a growing acceptance of MI approaches to restore FPMs instead of extraction of these teeth.

The effect of intraoperative dexmedetomidine on cognitive dysfunction after surgery: a updated meta-analysis

BackgroundPostoperative cognitive dysfunction (POCD) is one of the most common. Neuroprotective effects of dexmedetomidine (DEX) are reported in previous studies but evidence regarding the POCD is still unclear. In order to gain latest evidence, the present study analyzes the outcomes of randomized controlled trials (RCTs) which utilized DEX with general anaesthesia perioperatively.MethodFour online databases (PubMed, Embase, the Cochrane Library, and CNKI) were used to find relevant RCTs to conduct systematic analysis. All studies comparing the incidence of POCD or MMSE score between the DEX group and the placebo or comparator group in patients undergoing general anaesthetic surgery were eligible for inclusion. Based on the inclusion and exclusion criteria, the studies were selected. This meta-analysis was performed using odds ratios (ORs) with 95% confidence intervals (CIs) for dichotomous data and standardized mean difference (SMD) and 95% CIs for continuous data as effective measures.ResultsIn total of 21 studies were included in this meta-analysis. The results showed that the incidence of POCD in DEX group was significantly lower than the control group on the first (OR = 0.36, 95% CI 0.24–0.54),third (OR = 0.45,95% CI 0.33–0.61) and seventh (OR = 0.40,95% CI 0.26–0.60) postoperative days; the MMSE scores in DEX group were higher than the control group on the first (SMD = 1.24, 95% CI 1.08–1.41), third(SMD = 1.09, 95%CI 0.94–1.24) and seventh (SMD = 3.28, 95% CI 1.51–5.04) postoperative days.ConclusionsIntraoperative DEX use can ameliorate the POCD of patients who received surgical operations under general anesthesia, and effectively reduce the incidence of POCD and improve MMSE score.

A Novel Application of Ketamine for Improving Perioperative Sleep Disturbances.

Perioperative sleep disturbances are commonly observed before, during, and after surgery and can be caused by several factors, such as preoperative negative moods, general anesthetics, surgery trauma, and pain. Over the past decade, the fast-acting antidepressant effects of the N-methyl-D-aspartate (NMDA) receptor antagonist ketamine represent one of the most attractive discoveries in the field of psychiatry, such as antidepressant and anxiolytic effects. It is also widely used as a short-acting anesthetic and analgesic. Recent research has revealed new possible applications for ketamine, such as for perioperative sleep disorders and circadian rhythm disorders. Here, we summarize the risk factors for perioperative sleep disturbances, outcomes of perioperative sleep disturbances, and mechanism of action of ketamine in improving perioperative sleep quality.

The concentration of MMP-9 and the effects of intravenous anaesthetics on the efficacy of electroconvulsive therapy in patients with drug-resistant depression

Abstract Introduction: This study attempts to assess the concentration of intracellular matrix metalloproteinase (MMP-9) before and after the treatment of depressive episodes with ECT therapy and also to correlate the concentration of this enzyme with the use of commonly used general anaesthetics. Materials and methods: The study group comprised of 37 patients hospitalized in the Department of Adult Psychiatry in Poznan, with a diagnosis of episodes of drug-resistant depression during the course of bipolar and unipolar affective disorders, and who were being treated using electroconvulsive therapy. For the purpose of inducing anaesthesia during the procedure propofol was used in 10 cases, thiopental in 9 cases. Propofol was alternated with ketamine in a further 10 cases and thiopental was alternated with ketamine in another 9 cases. In order to assess the intensity of depression symptoms, the 17 point Hamilton depression scale was used, immediately before commencing ECT therapy, and one day after its completion. The serum concentration of MMP-9 was determined before and after the series of ECT treatments. In order to assess the serum concentration of MMP-9, an ELISA immunoenzymatic method was applied. Results: In this study, a significant reduction of MMP-9 concentration was noted after therapy, relative to the starting concentration, in the serum of patients suffering from depressive episodes resulting from either unipolar or bipolar affective disorders. These results correlated with improved psychiatric state, as assessed by the Hamilton scale. A significantly lower MMP-9 concentration was noted in the serum of patients given alternating thiopental and ketamine anaesthesia. Conclusions: This study suggests the importance of the enzyme as a biological marker for the effective treatment of depression. Furthermore, the choice of general anaesthetic applied during ECT also plays a role.

Curious Case of the Pretracheal Stethoscope

Curious Case of the Pretracheal Stethoscope

Supra-Arcuate Ligament Blocks: Anatomy, Mechanisms, and Techniques.

Quadratus lumborum block (QLB) is clinically used for postoperative analgesia of abdominal or hip surgery, which can reduce the dose of general anesthetic, inhibit postoperative pain, and promote postoperative rehabilitation. However, accumulated studies have shown several drawbacks of QLB, such as only a small portion of local anesthetic spread into the thoracic paravertebral space, relatively longer onset time, and easily-influenced block effect by the integrity of lumbar fascia, etc. Therefore, on the basis of traditional anterior QLB, our group proposed the techniques of a supra-arcuate ligament block, which include a paramedian short-axis scanning approach, paramedian long-axis scanning approach, infra-lateral arcuate ligament QLB with the apposition zone between diaphragm and quadratus lumborum as drug diffusion target and supra-arcuate ligament block under direct laparoscopic visualization. Recent studies have demonstrated that the supra-arcuate ligament blocks have the advantages of clear anatomy, are easy to perform, and have rapid onset, which avoid some drawbacks of the conventional QLB techniques. This article reviews the anatomical basis, sonoanatomy, technical points, and clinical considerations of supra-arcuate ligament blocks.

Duration of Exposure to General Endotracheal Anesthesia during Cesarean Deliveries at Term and Perinatal Complications.

To examine whether the duration of time from initiation of general endotracheal anesthesia (GETA) to delivery for cesarean deliveries (CDs) performed is related to perinatal outcomes. This is a retrospective study of patients with singleton nonanomalous gestations undergoing CD ≥37 weeks of gestation under GETA with reassuring fetal status at a single tertiary care center from 2000 to 2016. Duration from GETA initiation until delivery was calculated as the time interval from GETA induction to delivery (I-D), categorized into tertiles. Outcomes for those in the tertile with the shortest I-D were compared with those in the other two tertiles. The primary perinatal outcome was a composite of complications (continuous positive airway pressure or high-flow nasal cannula for ≥2 consecutive hours, inspired oxygen ≥30% for ≥4 consecutive hours, mechanical ventilation, stillbirth, or neonatal death ≤72 hours after birth). Secondary outcomes were 5-minute Apgar score <7 and a composite of maternal morbidity (bladder injury, bowel injury, and extension of hysterotomy). Bivariable and multivariable analyses were used to compare outcomes. Two hundred eighteen maternal-perinatal dyads were analyzed. They were dichotomized based on I-D ≤4 minutes (those in the tertile with the shortest duration) or >4 minutes. Women with I-D >4 minutes were more likely to have prior abdominal surgery and less likely to have labored prior to CD. I-D >4 minutes was associated with significantly increased frequency of the primary perinatal outcome. This persisted after multivariable adjustment. In bivariable analysis, 5-minute Apgar <7 was more common in the group with I-D >4 minutes, but this did not persist in multivariable analysis. Frequency of maternal morbidity did not differ. When CD is performed at term using GETA without evidence of nonreassuring fetal status prior to delivery, I-D interval >4 minutes is associated with increased frequency of perinatal complications. · Cesarean delivery under general anesthesia is associated with increased perinatal complications.. · Perinatal complications are increased with increasing duration of exposure to general anesthetics.. · Maternal complications were not increased with shorter duration of exposure to general anesthesia..

Common Determinants of Dental Caries and Obesity in Children: A Multi-Ethnic Nested Birth Cohort Study in the United Kingdom.

The article examines the common determinants of childhood dental caries and obesity. Longitudinal data from the Born in Bradford cohort study (BiB1000) (n = 1735) and dental data (dental general anaesthetics (GA) and oral health survey 2014/15) (n = 171) were used to test a framework on the social determinants of childhood dental caries (decayed, missing, filled teeth (dmft) index) and obesity (body mass index (BMI)). The BiB1000 data were collected at pregnancy week 26–28 and after birth at 6, 12, 18, 24 and 36 months. The determinants were demographics, wellbeing, socio-economic status (SES), dietary behaviours and physical activity behaviour of the children. Missing data were accounted for through multiple imputation (MI). The framework was tested through structural equation modelling. Overall, the model fit was adequate. No alcohol consumption of the mother after giving birth, higher frequency of child drinking sugar-sweetened beverages, emotional and behavioural difficulties of the child and being male were directly associated with both BMI and dental caries. Caregivers uninvolved or indulgent feeding style were associated with higher BMI and less dental caries. Social deprivation was associated with lower BMI and higher dmft. Five determinants were directly associated with BMI only. Fifteen indirect paths were significant for both child dental caries and BMI. The findings suggest common determinants for both childhood obesity and dental caries. Common risk factor approach seems appropriate for planning future health promotion programmes.

Epitranscriptomic Analysis of N6-methyladenosine in Infant Rhesus Macaques after Multiple Sevoflurane Anesthesia

Clinical investigations to date have proposed the possibility that exposure to anesthetics is associated with neurodevelopmental deficits. Sevoflurane is the most commonly used general anesthetic in pediatric patients. Animal studies have demonstrated that multiple exposures to sevoflurane during the postnatal period resulted in neuropathological brain changes and long-term cognitive deficits. However, the underlying mechanisms remain to be clarified. In this study, methylated RNA immunoprecipitation sequencing (MeRIP-Seq) was performed to acquire genome-wide profiling of RNA N6-methyladenosine (m6A) in the prefrontal cortex of infant rhesus macaques. The macaques in the sevoflurane group had more m6A peaks than the macaques in the control group (p ≤ 0.05). After sevoflurane treatment, the mRNA levels of YT521-B homology domain family 1 (YTHDF1) and YT521-B homology domain family 3 (YTHDF3) were decreased, and sevoflurane anesthesia dynamically regulated RNA m6A methylation. Gene ontology (GO) analysis revealed that after sevoflurane exposure, genes with increased methylation of m6A sites were enriched in some physiological processes relevant to neurodevelopment, mainly focused on synaptic plasticity. The female macaques had 18 hypermethylated genes. The males had 35 hypermethylated genes, and some physiological processes related to the regulation of synaptic structure were enriched. Rhesus macaques are genetically closer to human beings. Our findings can help in the study of the mechanism of sevoflurane-relevant neurodevelopmental deficits at the posttranscriptional level and can provide new insights into potential clinical preventions and interventions for the neurotoxicity of neonatal anesthesia exposure.

Dynamic reconfiguration of human brain networks across altered states of consciousness

Consciousness is supported by rich neuronal dynamics to orchestrate behaviors and conscious processing can be disrupted by general anesthetics. Previous studies suggested that dynamic reconfiguration of large-scale functional network is critical for learning and higher-order cognitive function. During altered states of consciousness, how brain functional networks are dynamically changed and reconfigured at the whole-brain level is still unclear. To fill this gap, using multilayer network approach and functional magnetic resonance imaging (fMRI) data of 21 healthy subjects, we investigated the dynamic network reconfiguration in three different states of consciousness: wakefulness, dexmedetomidine-induced sedation, and recovery. Applying time-varying community detection algorithm, we constructed multilayer modularity networks to track and quantify dynamic interactions among brain areas that span time and space. We compared four high-level network features (i.e., switching, promiscuity, integration, and recruitment) derived from multilayer modularity across the three conditions. We found that sedation state is primarily characterized by increased switching rates as well as decreased integration, representing a whole-brain pattern with higher modular dynamics and more fragmented communication; such alteration can be mostly reversed after the recovery of consciousness. Thus, our work can provide additional insights to understand the modular network reconfiguration across different states of consciousness and may provide some clinical implications for disorders of consciousness.

Play simulation for children in magnetic resonance imaging

IntroductionMagnetic Resonance Imaging (MRI) can be a challenging examination, particularly for children. The aim of this Clinical Perspective is to outline early experiences, based upon a service evaluation (defined as an assessment of how well the intended aims are achieved), of the Playful Magnetic Resonance Imaging Simulator (PMRIS) (Domed, Lyon, France) in reducing the number of children requiring general anaesthetic (GA) in order to undergo Magnetic Resonance Imaging (MRI). MethodsBaseline data from an audit of children undergoing MRI under GA in 2017 had previously been captured as part of the funding bid for the PMRIS. Estimation of costs associated with anaesthesia were made, then combined with the overall numbers of MRI under GA to estimate projected anaesthetic related cost-savings based on the reported effectiveness of the PMRIS. Once the PMRIS was in place, data were collected for children attending a Play Specialist supervised session. The number and age of children proceeding directly to MRI without requiring a GA was determined. The associated cost benefit was calculated and compared with the projections made in the initial funding bid. ResultsOver a 7 month period 36 children, average age 6 years, age range 4 to 11 years, who had initially been triaged for MRI under GA, attended a Play Specialist led session on the PMRIS. Of these, 30, average age 6 years, age range 4 to 11 years proceeded directly to MRI without a GA. Based on the costings used for the initial funding bid, this equates to a gross cost-saving of £9,000 over 7 months. DiscussionThis service evaluation shows a positive impact of Play Specialist sessions using the PMRIS with 30 out of 36 children having a successful awake MRI as a result. There are limitations to this evaluation, particularly that whilst all these children had been triaged for MRI under GA it cannot be known how many might have had an awake MRI with different preparation. Nevertheless, according to the local referral pathways these children would otherwise have had MRI under GA. ConclusionThis service evaluation has shown that the number of GAs required for children having MRI has reduced for this particular service through the use of the PMRIS, with Play Specialist support, with associated reduction in risk and cost savings.

Local anaesthetic techniques in endoscopic sinonasal surgery: a contemporaneous review.

Endoscopic endonasal surgery is a minimally invasive technique that has revolutionised the management of complex neurosurgical, otolaryngological, skull-base and craniofacial lesions. Traditionally performed under general anaesthetic, this study explores the growing role of local anaesthetic techniques. A contemporaneous review of modified dental techniques and intraoral anatomy provides a supportive guide for performing endoscopic sinus surgery under local anaesthetic. The practical procedures for four midfacial nerve blocks are described with relevance to endoscopic surgery under local anaesthetic. Anatomy, surgical technique and potential complications are discussed for the incisive foramen block, sphenopalatine ganglion block (via endonasal approach), maxillary nerve block (via the greater palatine foramen and the transoral lateral pterygoid plate approach) and transcutaneous approach to the pterygomaxillary fissure. Ultimately, such techniques may extend the safety and efficacy of endoscopic sinus surgery, limit surgical risk and increase satisfaction for patients, surgeons and healthcare managers alike.

Propofol and Sevoflurane Anesthesia in Early Childhood Do Not Influence Seizure Threshold in Adult Rats.

Experimental studies have demonstrated that general anesthetics administered during the period of synaptogenesis may induce widespread neurodegeneration, which results in permanent cognitive and behavioral deficits. What remains to be elucidated is the extent of the potential influence of the commonly used hypnotics on comorbidities including epilepsy, which may have resulted from increased neurodegeneration during synaptogenesis. This study aimed to test the hypothesis that neuropathological changes induced by anesthetics during synaptogenesis may lead to changes in the seizure threshold during adulthood. Wistar rat pups were treated with propofol, sevoflurane, or saline on the sixth postnatal day. The long-term effects of prolonged propofol and sevoflurane anesthesia on epileptogenesis were assessed using corneal kindling, pilocarpine-, and pentylenetetrazole-induced seizure models in adult animals. Body weight gain was measured throughout the experiment. No changes in the seizure threshold were observed in the three models. A significant weight gain after exposure to anesthetics during synaptogenesis was observed in the propofol group but not in the sevoflurane group. The results suggest that single prolonged exposure to sevoflurane or propofol during synaptogenesis may have no undesirable effects on epileptogenesis in adulthood.

Propofol ameliorates acute postoperative fatigue and promotes glucagon-regulated hepatic gluconeogenesis by activating CREB/PGC-1α and accelerating fatty acids beta-oxidation

Postoperative fatigue (POF) is the most common and long-lasting complication after surgery, which brings heavy burden to individuals and society. Recently, hastening postoperative recovery receives increasing attention, but unfortunately, the mechanisms underlying POF remain unclear. Propofol is a wildly used general anesthetic in clinic, and inspired by the rapid antidepressant effects induced by ketamine at non-anesthetic dose, the present study was undertaken to investigate the anti-fatigue effects and underlying mechanisms of propofol at a non-anesthetic dose in 70% hepatectomy induced POF model in rats. We first showed here that single administration of propofol at 0.1 mg/kg ameliorated acute POF in hepatectomy induced POF rats. Based on metabonomics analysis, we hypothesized that propofol exerted anti-fatigue activity in POF rats by facilitating free fatty acid (FFA) oxidation and gluconeogenesis. We further confirmed that propofol restored the deficit in FFA oxidation and gluconeogenesis in POF rats, as evidenced by the elevated FFA utilization, acetyl coenzyme A content, pyruvic acid content, phosphoenolpyruvic acid content, hepatic glucose output and glycogen storage. Moreover, propofol stimulated glucagon secretion and up-regulated expression of cAMP-response element binding protein (CREB), phosphorylated CREB, peroxlsome prolifeator-activated receptor-γ coactivator-1α (PGC-1α), phosphoenolpyruvate carboxykinade1 and carnitine palmitoltransferase 1A. In summary, our study suggests for the first time that propofol ameliorates acute POF by promoting glucagon-regulated gluconeogenesis via CREB/PGC-1α signaling and accelerating FFA beta-oxidation.

Inhalational Anesthetics Do Not Deteriorate Amyloid-β-Derived Pathophysiology in Alzheimer's Disease: Investigations on the Molecular, Neuronal, and Behavioral Level.

Studies suggest that general anesthetics like isoflurane and sevoflurane may aggravate Alzheimer's disease (AD) neuropathogenesis, e.g., increased amyloid-β (Aβ) protein aggregation resulting in synaptotoxicity and cognitive dysfunction. Other studies showed neuroprotective effects, e.g., with xenon. In the present study, we want to detail the interactions of inhalational anesthetics with Aβ-derived pathology. We hypothesize xenon-mediated beneficial mechanisms regarding Aβ oligomerization and Aβ-mediated neurotoxicity on processes related to cognition. Oligomerization of Aβ1-42 in the presence of anesthetics has been analyzed by means of TR-FRET and silver staining. For monitoring changes in neuronal plasticity due to anesthetics and Aβ1-42, Aβ1-40, pyroglutamate-modified amyloid-(AβpE3), and nitrated Aβ (3NTyrAβ), we quantified long-term potentiation (LTP) and spine density. We analyzed network activity in the hippocampus via voltage-sensitive dye imaging (VSDI) and cognitive performance and Aβ plaque burden in transgenic AD mice (ArcAβ) after anesthesia. Whereas isoflurane and sevoflurane did not affect Aβ1-42 aggregation, xenon alleviated the propensity for aggregation and partially reversed AβpE3 induced synaptotoxic effects on LTP. Xenon and sevoflurane reversed Aβ1-42-induced spine density attenuation. In the presence of Aβ1-40 and AβpE3, anesthetic-induced depression of VSDI-monitored signaling recovered after xenon, but not isoflurane and sevoflurane removal. In slices pretreated with Aβ1-42 or 3NTyrAβ, activity did not recover after washout. Cognitive performance and plaque burden were unaffected after anesthetizing WT and ArcAβ mice. None of the anesthetics aggravated Aβ-derived AD pathology in vivo. However, Aβ and anesthetics affected neuronal activity in vitro, whereby xenon showed beneficial effects on Aβ1-42 aggregation, LTP, and spine density.

Near-infrared triggered ropivacaine liposomal gel for adjustable and prolonged local anaesthesia

Local analgesics effectively allow patients to relieve postoperative pain and reduce the need for inhaled general anesthetics or opioids. Compared with other similar long-acting local anesthetics, ropivacaine (Rop) is widely used due to its potential to minimize cardiotoxicity. However, the relatively short duration of Rop efficacy, which lasts for several hours after injection, is considered insufficient for long-term acute and chronic pain treatment. At present, repeated injections or indwelling catheters are used to achieve long-term drug delivery, which can easily cause infection and inflammation. To achieve externally controllable analgesia for a prolonged time, we prepared near-infrared (NIR)-responsive Rop liposomes (Rop@Lip) containing photosensitizers PdPC(OBu)8 and unsaturated phospholipid DLPC. The particle size of the Rop@Lip was 234.73 ± 5.21 nm, the PDI was 0.42 ± 0.02, and the drug encapsulation rate was 94.62 ± 1.1%. The release of Rop was highly NIR-dependent in vitro and in vivo. To ensure that the liposomes reside around the nerve for an extended period, we next designed an in situ gel with chitosan (CS) and β-sodium glycerophosphate (β-GP) to form a liposomal gel (Lip/Gel). This Lip/Gel composite drug delivery system could be retained in vivo for 10 d, reduce the side effects caused by drug overdose, and prolong the duration of efficacy. In summary, the NIR-responsive Rop composite drug delivery system generated in this paper can effectively solve the shortcomings of traditional local injections, reduce the toxicity and side effects of free Rop, and provide a basis for a light-responsive delivery system of analgesic drugs.

Monitoring Temperature in Children Under General Anesthesia: Nasopharynx Versus Carotid Artery Surface

Continuous body temperature monitoring during anesthesia in children is very important. Hypothermia in children may lead to higher morbidity and mortality. Measurement points to detect the temperature of core body are not simply accessible. In this study we measured the skin temperature over the carotid artery and compared it with the nasopharynx. Totally, 84 children of 2-10 years undergoing elective surgery were selected. Temperature over the carotid artery and nasopharynx was measured during anesthesia. Mean temperature of these points was compared which each other, and the effects of age, sex, and weight change of temperature during anesthesia were evaluated. The mean age of patients was 5.4±2.6 years s. 37% of patients were female, and 63% were male. The mean weight was 20±7 kg. The mean duration of surgery was 60.45±6.65 min. The temperature of the skin and nasopharynx was decreased during surgery as after 60 min, the deference between skin over the carotid artery and the nasopharyngeal area was 1° C. The bodyweight has a significant effect on carotid skin temperature in regression model. Skin temperature over the carotid artery, with a simple correction factor of+1° C, provides a viable noninvasive estimate of nasopharyngeal temperature in children during elective surgery with a general anesthetic.