A Cost Analysis of Carpal Tunnel Release Surgery Performed Wide Awake versus under Sedation.

BACKGROUND: Hand surgery under local anesthesia only has been used more frequently in recent years. The purpose of this study was to compare perioperative time and cost for carpal tunnel release performed under local anesthesia ( wide-awake local anesthesia no tourniquet, or WALANT) only to carpal tunnel release performed under intravenous sedation. METHODS: A retrospective comparison of intraoperative (operating room) surgical time and postoperative (postanesthesia care unit) time for consecutive carpal tunnel release procedures performed under both intravenous sedation and wide-awake local anesthesia was undertaken. All operations were performed by the same surgeon using the same mini-open surgical technique. A cost analysis was performed by means of standardized anesthesia billing based on base units, time, and conversion rates. RESULTS: There were no significant differences between the two groups in terms of total operative time, 28 minutes in the intravenous sedation group versus 26 minutes in the wide-awake local anesthesia group. Postanesthesia care unit times were significantly longer in the intravenous sedation group (84 minutes) compared to the wide-awake local anesthesia group (7 minutes). Depending on conversion rates used, a total of $139 to$432 was saved in each case performed with wide-awake local anesthesia by not using anesthesia services. In addition, a range of $1320 to$1613 was saved for the full episode of care, including anesthesia costs, operating room time, and postanesthesia care unit time for each patient undergoing wide-awake local anesthesia carpal tunnel release. CONCLUSION: Carpal tunnel release surgery performed with the wide-awake local anesthesia technique offers significant reduction in cost for use of anesthesia and postanesthesia care unit resources

Direct Current Auditory Evoked Potentials During Wakefulness, Anesthesia, and Emergence from Anesthesia

Direct current auditory evoked potentials (DC-AEPs) are a sensitive indicator of depth of anesthesia in ani-mals. However, they have never been investigated in humans. To assess the potential usefulness of DC-AEPs as an indicator of anesthesia in humans, we performed an explorative study in which DC-AEPs were recorded during propofol and methohexital anesthesia in hu-mans. DC-AEPs were recorded via 22 scalp electrodes in 19 volunteers randomly assigned to receive either propofol or methohexital. DC-AEPs were evoked by binaurally presented 2-s, 60-dB, 800-Hz tones; meas-urements were taken during awake baseline, anesthesia, and emergence. Statistical analysis included analy-sis of variance and discriminant analysis of data acquired during these three conditions. About 500 ms after stimulus presentation, DC-AEPs could be ob-served. These potentials were present only during base-line and emergence—not during anesthesia. Statistically significant differences were found between baseline and anesthesia and between anesthesia and emergence. In conclusion, similar effects, as reported in animal studies of anesthetics on the DC-AEPs, could be observed in anesthetized humans. These results dem-onstrate that DC-AEPs are potentially useful in the assessment of cortical function during anesthesia and might qualify the method for monitoring anesthesia in humans

General anesthesia reduces complexity and temporal asymmetry of the informational structures derived from neural recordings in Drosophila

We apply techniques from the field of computational mechanics to evaluate the statistical complexity of neural recording data from fruit flies. First, we connect statistical complexity to the flies' level of conscious arousal, which is manipulated by general anesthesia (isoflurane). We show that the complexity of even single channel time series data decreases under anesthesia. The observed difference in complexity between the two states of conscious arousal increases as higher orders of temporal correlations are taken into account. We then go on to show that, in addition to reducing complexity, anesthesia also modulates the informational structure between the forward- and reverse-time neural signals. Specifically, using three distinct notions of temporal asymmetry we show that anesthesia reduces temporal asymmetry on information-theoretic and information-geometric grounds. In contrast to prior work, our results show that: (1) Complexity differences can emerge at very short timescales and across broad regions of the fly brain, thus heralding the macroscopic state of anesthesia in a previously unforeseen manner, and (2) that general anesthesia also modulates the temporal asymmetry of neural signals. Together, our results demonstrate that anesthetized brains become both less structured and more reversible.Comment: 14 pages, 6 figures. Comments welcome; Added time-reversal analysis, updated discussion, new figures (Fig. 5 & Fig. 6) and Tables (Tab. 1

Cognitive dysfunction following desflurane versus sevoflurane general anesthesia in elderly patients: a randomized controlled trial.

UnlabelledAs life expectancy increases, more patients ≥65 years undergo general anesthesia. Anesthetic agents may contribute to postoperative cognitive dysfunction, and incidence may differ with anesthetic agents or intraoperative anesthesia depth. Responses to anesthetic adjuvants vary among elderly patients. Processed electroencephalography guidance of anesthetic may better ensure equivalent cerebral suppression. This study investigates postoperative cognitive dysfunction differences in elderly patients given desflurane or sevoflurane using processed electroencephalography guidance.IRB approved, randomized trial enrolled consenting patients ≥65 years scheduled for elective surgery requiring general anesthesia ≥120 minute duration. After written informed consent, patients were randomly assigned to sevoflurane or desflurane. No perioperative benzodiazepines were administered. Cognitive impairment was measured by an investigator blinded to group assignment using mini-Mental Status Examination (MMSE) at baseline; 1, 6, and 24 hours after the end of anesthesia. Mean arterial pressure was maintained within 20% of baseline. Anesthetic dose was adjusted to maintain moderate general anesthesia per processed electroencephalograpy (Patient State Index 25 to 50). The primary outcome measure was intergroup difference in MMSE change 1 hour after anesthesia (median; 95% confidence interval).110 patients consented; 26 were not included for analysis (no general anesthesia; withdrew consent; baseline MMSE abnormality; inability to perform postoperative MMSE; data capture failure); 47 sevoflurane and 37 desflurane were analyzed. There were no significant differences in patient characteristics; intraoperative mean blood pressure (desflurane 86.4; 81.3 to 89.6 versus sevoflurane 82.5; 80.2 to 86.1 mmHg; p = 0.42) or Patient State Index (desflurane 41.9; 39.0 to 44.0 versus sevoflurane 41.0; 37.5 to 44.0; p = 0.60) despite a lower MAC fraction in desflurane (0.82; 0.77 to 0.86) versus sevoflurane (0.96; 0.91 to 1.03; p < 0.001). MMSE decreased 1 hour after anesthesia (p < 0.001). The decrease at one hour was larger in sevoflurane (-2.5; -3.3 to -1.8) than desflurane (-1.3; -2.2 to -0.5; p = 0.03). MMSE returned to baseline by 6 hours after anesthesia.ConclusionsFor elderly patients in whom depth of anesthesia is maintained in the moderate range, both desflurane and sevoflurane are associated with transient decreases in cognitive function as measured by MMSE after anesthesia, with clinically insignificant differences between them in this setting.Trial registryClinicalTrials.gov NCT01199913

Hypothesis of Rfmra Development – the Receptor-focused Magnetic and Resonant Anesthesia

This article is described the hypothesis of the solution how to create the "ideal anesthesia". Theoretical justification of the innovative technique of the Receptor-focused Magnetic Resonance anesthesia is offered. It should be use the "ideal anesthetic" as which the electromagnetic model of a medicinal preparation for anesthesia acts. Stages of carrying out the offered type of anesthesia have offered. For the practical application of the proposed idea it would be implemented a number of innovations. First, it includes technologies of a magnetic and resonant tomography of high resolution (less than 100 microns). At the second, it would be technologies of creation electromagnetic models of the existing medical preparations. Than it would be on-line technologies of formation the 3D base of addresses of receptors for anesthesia of organism of a particular person. In addition, technologies of a triggering the cascade of biochemical reactions is proposed, by the modeling of pharmacodynamics electromagnetic models of a medicinal preparation.Such type of anesthesia will allow to avoid side effects of medical preparations at stages of an absorption, distribution, removal that are caused by the mass of drug and, in addition, respectively, to reach therapeutic effect only by means of electromagnetic model of a medicinal preparation for anesthesia

The use of intra-articular aneshesia as a diagnostic tool in canine lameness

Lameness in dogs may be difficult to localize because of mild pathologic changes or inconclusive clinical findings. Intra-articular anesthesia is proposed as a diagnostic method to localize the source of lameness. After a description of the preparation, technique and puncture sites, an overview is given of a series of patients admitted for different joint problems. Intra-articular anesthesia proved to be applicable in any joint, provided that the clinician was experienced and the dog was under sedation. In 87% of the cases, intra-articular anesthesia was positive. Medial coronoid disease of the elbow joint was the most frequent indication for intra-articular anesthesia

Monosynaptic Functional Connectivity in Cerebral Cortex During Wakefulness and Under Graded Levels of Anesthesia

The balance between excitation and inhibition is considered to be of significant importance for neural computation and cognitive function. Excitatory and inhibitory functional connectivity in intact cortical neuronal networks in wakefulness and graded levels of anesthesia has not been systematically investigated. We compared monosynaptic excitatory and inhibitory spike transmission probabilities using pairwise cross-correlogram (CCG) analysis. Spikes were measured at 64 sites in the visual cortex of rats with chronically implanted microelectrode arrays during wakefulness and three levels of anesthesia produced by desflurane. Anesthesia decreased the number of active units, the number of functional connections, and the strength of excitatory connections. Connection probability (number of connections per number of active unit pairs) was unaffected until the deepest anesthesia level, at which a significant increase in the excitatory to inhibitory ratio of connection probabilities was observed. The results suggest that the excitatory–inhibitory balance is altered at an anesthetic depth associated with unconsciousness

Propofol Induction Reduces the Capacity for Neural Information Integration: Implications for the Mechanism of Consciousness and General Anesthesia

The cognitive unbinding paradigm suggests that the synthesis of cognitive information is attenuated by general anesthesia. Here, we investigated the functional organization of brain activities in the conscious and anesthetized states, based on characteristic functional segregation and integration of electroencephalography (EEG). EEG recordings were obtained from 14 subjects undergoing induction of general anesthesia with propofol. We quantified changes in mean information integration capacity in each band of the EEG. After induction with propofol, mean information integration capacity was reduced most prominently in the gamma band of the EEG (p=0.0001). Furthermore, we demonstrate that loss of consciousness is reflected by the breakdown of the spatiotemporal organization of gamma waves. Induction of general anesthesia with propofol reduces the capacity for information integration in the brain. These data directly support the information integration theory of consciousness and the cognitive unbinding paradigm of general anesthesia

Maxillary nerve block: A comparison between the greater palatine canal and high tuberosity approaches.

Aim: Analgesia and anxiolysis during dental procedures are important for dental care and patient compliance. This study aims to compare two classical maxillary nerve block (MNB) techniques: the greater palatine canal (GPC) and the high tuberosity (HT) approaches, seldom used in routine dental practice. Methods: The study was conducted on 30 patients, scheduled for sinus lift surgery, who were randomly divided into 2 groups: the GPC approach to the MNB was used in 15 and the HT one in the other 15 patients. Anxiolysis was also used, depending on the results of the pre- preoperative assessment. Patients\u2019 sensations/pain during the procedure, details about anesthesia, and the dentist\u2019s considerations were all recorded. Data are expressed as mean \ub1SD. Statistical tests including ANOVA, \u3c72 following Yates correction and linear regression analysis were carried out. A < 0.05 p value was considered significant. Results: Study results showed that the anesthesia was effective and constant in the molar and premolar area. Additional infiltrations of local anesthetics were necessary for vestibular and palatal areas in the anterior oral cavity, respectively, in the GPC and HT groups. The two techniques were equally difficult to carry out in the dentist\u2019s opinion. There were no differences in pain or unpleasant sensations between the two groups, nor were any anesthesia-related complications reported. Conclusion: The GPC approach ensures effective anesthesia in the posterior maxillary region as far as both the dental pulp and the palatal/vestibular mucous membranes are concerned; the HT approach did not guarantee adequate anesthesia of the pterygopalatine branch of the maxillary nerve. These regional anesthesia techniques were characterized by a low incidence of intra and postoperative pain, no noteworthy complications, and high patient satisfaction

General anesthesia does not have persistent effects on attention in rodents

Background: Studies in animals have shown that general anesthesia can cause persistent spatial memory impairment, but the influence of anesthetics on other cognitive functions is unclear. This study tested whether exposure to general anesthesia without surgery caused a persistent deficit in attention in rodents.Methods: To evaluate whether anesthesia has persistent effects on attention, rats were randomized to three groups. Group A was exposed for 2 h to isoflurane anesthesia, and tested the following seven days for attentional deficits. Group B was used as a control and received room air before attentional testing. Since there is some evidence that a subanesthetic dose of ketamine can improve cognition and reduce disorders of attention after surgery, rats in group C were exposed to isoflurane anesthesia in combination with a ketamine injection before cognitive assessment. Attention was measured in rats using the 5-Choice Serial Reaction Time Task, for which animals were trained to respond with a nose poke on a touchscreen to a brief, unpredictable visual stimulus in one of five possible grid locations to receive a food reward. Attention was analyzed as % accuracy, % omission, and premature responses.Results: Evaluating acute attention by comparing baseline values with data from the day after intervention did not reveal any differences in attentional measurements. No significant differences were seen in % accuracy, % omission, and premature responses for the three groups tested for 7 consecutive days.Conclusion: These data in healthy rodents suggest that general anesthesia without surgery has no persistent effect on attention and the addition of ketamine does not alter the outcome