- 作者列表："Redinbaugh MJ","Phillips JM","Kambi NA","Mohanta S","Andryk S","Dooley GL","Afrasiabi M","Raz A","Saalmann YB
:Functional MRI and electrophysiology studies suggest that consciousness depends on large-scale thalamocortical and corticocortical interactions. However, it is unclear how neurons in different cortical layers and circuits contribute. We simultaneously recorded from central lateral thalamus (CL) and across layers of the frontoparietal cortex in awake, sleeping, and anesthetized macaques. We found that neurons in thalamus and deep cortical layers are most sensitive to changes in consciousness level, consistent across different anesthetic agents and sleep. Deep-layer activity is sustained by interactions with CL. Consciousness also depends on deep-layer neurons providing feedback to superficial layers (not to deep layers), suggesting that long-range feedback and intracolumnar signaling are important. To show causality, we stimulated CL in anesthetized macaques and effectively restored arousal and wake-like neural processing. This effect was location and frequency specific. Our findings suggest layer-specific thalamocortical correlates of consciousness and inform how targeted deep brain stimulation can alleviate disorders of consciousness.
: 功能性MRI和电生理学研究表明，意识依赖于大规模的丘脑皮质和皮质皮质相互作用。然而，目前还不清楚不同皮层和回路中的神经元是如何起作用的。我们同时记录了清醒、睡眠和麻醉猕猴的中央侧丘脑 (CL) 和跨额顶皮层层。我们发现丘脑和深皮层的神经元对意识水平的变化最敏感，在不同的麻醉剂和睡眠中保持一致。深层活性通过与CL的相互作用来维持。意识还依赖于深层神经元向表层 (而不是深层) 提供反馈，这表明远程反馈和腔内信号传导很重要。为了显示因果关系，我们在麻醉的猕猴中刺激CL并有效地恢复唤醒和唤醒样神经处理。这种效应是位置和频率特异性的。我们的研究结果表明，意识与层特异性丘脑皮质相关，并告知靶向深部脑刺激如何缓解意识障碍。
METHODS:BACKGROUND:Anxiety and distress behaviors during anesthesia induction are associated with negative postoperative outcomes for pediatric patients. Documenting behavioral responses to induction is useful to evaluate induction quality at hospitals and to optimize future anesthetics for returning patients, but we lack a simple tool for clinical documentation. The Induction Compliance Checklist is a tool for grading induction behaviors that is well validated for research purposes, but it is not practical for routine documentation in busy clinical practice settings. The Child Induction Behavioral Assessment tool was developed to provide a simple and easy to use electronic tool for clinical documentation of induction behaviors. The aim of this study was to test the Child Induction Behavioral Assessment tool's concurrent validity with the Induction Compliance Checklist and the interrater reliability. METHODS:This prospective, observational study included 384 pediatric patients undergoing anesthesia inhalation induction. Concurrent validity with the Induction Compliance Checklist and interrater reliability of the Child Induction Behavioral Assessment were evaluated. Two researchers alternated scoring the Induction Compliance Checklist. The 2 researchers independently scored the Child Induction Behavioral Assessment. The anesthesia clinician caring for the patient also independently scored the Child Induction Behavioral Assessment by completing their routine documentation in the patient's medical record. Two age groups were evaluated (ages 1-3 and 4-12 years old). RESULTS:Clinicians' and researchers' Child Induction Behavioral Assessment scores demonstrated a strong correlation with the Induction Compliance Checklist (P < .0001). There was an excellent agreement between the 2 researchers' Child Induction Behavioral Assessment scores for the younger and older age groups, respectively (Kappa [95% CI] = 0.97 (0.94-0.99); K = 0.94 (0.89-0.99)]. The agreement between the researchers and the 117 clinicians who documented Child Induction Behavioral Assessment assessments in the medical record was good overall (intraclass correlation coefficient = 0.70), with fair agreement with the 1- to 3-year-old patients (intraclass correlation coefficient = 0.56) and good agreement for the 4- to 12-year-old patients (intraclass correlation coefficient = 0.74). CONCLUSIONS:The Child Induction Behavioral Assessment scale is a simple and practical electronic tool used to document pediatric behavioral responses to anesthesia inductions. This study provides evidence of the tool's validity and reliability for inhalation inductions. Future research is needed at other hospitals to confirm validity.
METHODS:BACKGROUND:Fentanyl and morphine are the 2 most commonly added opioids to bupivacaine for spinal anesthesia during cesarean delivery. Numerous clinical trials have assessed efficacy and safety of different doses of fentanyl added to intrathecal bupivacaine for spinal anesthesia, yet its benefit, harm, and optimal dose remain unclear. This study aimed to systematically review the evidence of the efficacy of fentanyl when added to intrathecal bupivacaine alone and when added to bupivacaine with morphine for spinal anesthesia during cesarean delivery. METHODS:Key electronic databases (PubMed, Embase, and Cochrane Library) were searched for randomized controlled trials in the cesarean delivery population. The primary outcome was the failure rate of spinal anesthesia, as assessed by the need for either conversion to general anesthesia or intraoperative analgesic supplementation. Two reviewers independently extracted the data using a standardized electronic form. Results are expressed as relative risks or mean differences with 95% CIs. RESULTS:Seventeen randomized controlled clinical trials (most judged as low or unclear risk of bias) with 1064 participants provided data for the meta-analysis. Fentanyl added to intrathecal bupivacaine alone reduced the need for intraoperative supplemental analgesia (relative risk, 0.18; 95% CI, 0.11-0.27; number needed to treat, 4) and the incidence of nausea/vomiting (relative risk, 0.41; 95% CI, 0.24-0.70; number needed to treat, 6.5), with longer time to first postoperative analgesia request (mean difference, 91 minutes; 95% CI, 69-113). No difference was observed regarding the need for conversion to general anesthesia (relative risk, 0.67; 95% CI, 0.12-3.57), the incidence of hypotension, the onset of sensory block, or the duration of motor block. However, the addition of intrathecal fentanyl was associated with higher incidence of intraoperative pruritus (relative risk, 5.89; 95% CI, 2.07-16.79; number needed to harm, 13.5). The inclusion of fentanyl to intrathecal bupivacaine-morphine compared to intrathecal bupivacaine-morphine alone conferred a similar benefit, with a significantly reduced need for intraoperative supplemental analgesia (relative risk, 0.16; 95% CI, 0.03-0.95; number needed to treat, 9). Analysis using a funnel plot indicated a possibility of publication bias in included studies. CONCLUSIONS:Current evidence suggests a benefit of using fentanyl as both an additive to intrathecal bupivacaine alone and to intrathecal bupivacaine combined with morphine for cesarean delivery under spinal anesthesia. The possibility of publication bias, small sample size, and high risk of bias in some of the included studies warrant treating the results with caution.
METHODS::Ophthalmic pediatric regional anesthesia has been widely described, but infrequently used. This review summarizes the available evidence supporting the use of conduction anesthesia in pediatric ophthalmic surgery. Key anatomic differences in axial length, intraocular pressure, and available orbital space between young children and adults impact conduct of ophthalmic regional anesthesia. The eye is near adult size at birth and completes its growth rapidly while the orbit does not. This results in significantly diminished extraocular orbital volumes for local anesthetic deposition. Needle-based blocks are categorized by relation of the needle to the extraocular muscle cone (ie, intraconal or extraconal) and in the cannula-based block, by description of the potential space deep to the Tenon capsule. In children, blocks are placed after induction of anesthesia by a pediatric anesthesiologist or ophthalmologist, via anatomic landmarks or under ultrasonography. Ocular conduction anesthesia confers several advantages for eye surgery including analgesia, akinesia, ablation of the oculocardiac reflex, and reduction of postoperative nausea and vomiting. Short (16 mm), blunt-tip needles are preferred because of altered globe-to-orbit ratios in children. Soft-tip cannulae of varying length have been demonstrated as safe in sub-Tenon blockade. Ultrasound technology facilitates direct, real-time visualization of needle position and local anesthetic spread and reduces inadvertent intraconal needle placement. The developing eye is vulnerable to thermal and mechanical insults, so ocular-rated transducers are mandated. The adjuvant hyaluronidase improves ocular akinesia, decreases local anesthetic dosage requirements, and improves initial block success; meanwhile, dexmedetomidine increases local anesthetic potency and prolongs duration of analgesia without an increase in adverse events. Intraconal blockade is a relative contraindication in neonates and infants, retinoblastoma surgery, and in the presence of posterior staphylomas and buphthalmos. Specific considerations include pertinent pediatric ophthalmologic topics, block placement in the syndromic child, and potential adverse effects associated with each technique. Recommendations based on our experience at a busy academic ophthalmologic tertiary referral center are provided.