Narrow Results

Dynamically assessing the level of consciousness is still challenging during anesthesia. With the help of Electroencephalography (EEG), the human brain electric activity can be noninvasively measured at high temporal resolution. Several typical quasi-stable states are introduced to represent the oscillation of the global scalp electric field. These so-called microstates reflect spatiotemporal dynamics of coherent neural activities and capture the switch of brain states within the millisecond range. In this study, the microstates of high-density EEG were extracted and investigated during propofol-induced transition of consciousness. To analyze microstates on the frequency domain, a novel microstate-wise spectral analysis was proposed by the means of multivariate empirical mode decomposition and Hilbert–Huang transform. During the transition of consciousness, a map with a posterior central maximum denoted as microstate F appeared and became salient. The current results indicated that the coverage, occurrence, and power of microstate F significantly increased in moderate sedation. The results also demonstrated that the transition of brain state from rest to sedation was accompanied by significant increase in mean energy of all frequency bands in microstate F. Combined with studies on the possible cortical sources of microstates, the findings reveal that non-canonical microstate F is highly associated with propofol-induced altered states of consciousness. The results may also support the inference that this distinct topography can be derived from canonical microstate C (anterior-posterior orientation). Finally, this study further develops pertinent methodology and extends possible applications of the EEG microstate during propofol-induced anesthesia.

Patients usually fear fiberoptic bronchoscopy (FBS) and they report a low level of satisfaction after this examination. We evaluated the efficacy of acupuncture in decreasing patient anxiety before diagnostic FBS and in improving tolerance to the examination. In a prospective double-blind study, we enrolled 48 patients scheduled to undergo diagnostic FBS. Patients were randomly assigned to one of three groups. Group A (16 patients): standard FBS, with airway topic anesthesia; Group B (16 patients): standard FBS, with airway topic anesthesia and acupuncture treatment; Group C (16 patients): standard FBS, with airway topic anesthesia and sham acupuncture. EKG, non-invasive arterial pressure, and pulse oximetry were monitored on a routine basis. We evaluated patient anxiety before and after acupuncture and, at the end of FBS, the discomfort suffered during the examination by a 100-mm Visual Analog Scale (VAS).

Patient satisfaction in Group A was 50% worse than in Group B (p = 0.04). We observed a strong, even if not statistically significant, tendency toward a lower pre-FBS anxiety in Group B. Patients in group C had values very close to those recorded in group A. We observed no adverse event and no differences in cardio-respiratory parameters in these three groups; in particular, we did not observe a respiratory depression in Group B.

Acupuncture seems an effective resource for a Thoracic Endoscopic Room to improve patient tolerance to FBS.

Anesthesiology aims to make anesthesia safer and increase the precision of prognoses. Correct assessment of the anesthesia depth is crucial to its safety. At present, intraoperative electroencephalogram (EEG) monitoring is the primary mode of anesthesia depth monitoring and judgment. However, most clinical anesthesiologists rely on commercial anesthesia depth monitors to judge anesthesia depth, such as bispectral index (BIS) and patient state index (PSI). This may lack an understanding of associated changes in brain wave quantization. Therefore, this study conducts quantitative analyses of EEG signals during anesthesia induction. EEG signals are processed within specific time windows and extracted brainpower density spectrum arrays with different frequency bands, brain electrical signal spectra, source frequencies and other key indicators. Analysis and comparison of these indicators clarifies patterns of variation in EEG signals during early anesthesia induction. The spectral edge frequencies (SEFs) of EEG signals within different time windows can be modeled accurately, from which the specific time points of EEG signal changes are derived. Furthermore, the relationship between patient age and the effect of anesthetic drugs is preliminarily investigated by analyzing the SEF variations of different age groups. This study quantifies changes in the EEG signals of patients at the initial stage of anesthesia induction and drug-related effects are observed, which opens a way for further exploration of EEG changes in patients under general anesthesia.

The complexity, entropy and other non-linear measures of the electroencephalogram (EEG), such as Higuchi fractal dimension (FD), have been recently proposed as the measures of anesthesia depth and sedation. We hypothesized that during unconciousness in rats induced by the general anesthetics with opposite mechanism of action, behaviorally and poligraphically controlled as appropriately achieved stable anesthesia, we can detect distinct inter-structure brain dynamic using mean FDs. We used the surrogate data test for nonlinearity in order to establish the existence of nonlinear dynamics, and to justify the use of FD as a nonlinear measure in the time series analysis. The surrogate data of predefined probability distribution and autocorrelation properties have been generated using the algorithm of statically transformed autoregressive process (STAP). FD then is applied to quantify EEG signal complexity at the cortical, hippocampal and pontine level during stable general anesthesia (ketamine/xylazine or nembutal anesthesia).

Our study showed for the first time that global neuronal inhibition caused by different mechanisms of anesthetic action induced distinct brain inter-structure complexity gradient in Sprague Dawley rats. EEG signal complexities were higher at cortical and hippocampal level in ketamine/xylazine vs. nembutal anesthesia, with the dominance of hippocampal complexity. In nembutal anesthesia the complexity dominance moved to pontine level, and ponto-hippocampo-cortical decreasing complexity gradient was established. This study has proved the Higuchi fractal dimension as a valuable tool for measuring the anesthesia induced inter-structure EEG complexity.

Background: To present the efficacy of 1:1,000,000 tumescent solution for resection of vascular malformation in hand and upper extremity without tourniquet application.

Methods: Four patients with five slow flow vascular malformations were retrospectively reviewed. Prior to incision, 1:1,000,000 tumescent solution was infiltrated subcutaneously surrounding the lesion until the skin turned pale. Amount of tumescent solution injected, the length of surgery, the clarity of the operative field, and the complications were recorded. Clarity of operative field was categorized as totally bloodless, minimum bleeding, acceptable bleeding, and bloody. In the surgeries under local anesthesia, we also recorded self-reported intra-operative pain using VAS score, onset of pain, and conversion of anesthesia.

Results: The injected amount of the tumescent solution ranged from 4.5 to 200 mL, with the length of surgery ranged from 60 to 150 minutes. One out of 5 cases was totally bloodless, 3 cases were minimum bleeding and 1 case was acceptable bleeding. Minor skin necrosis was recorded in 1 patient. Neither intra-operative pain nor conversion from local to general anesthesia was reported.

Conclusions: 1:1,000,000 tumescent solution is effective for resection of slow flow vascular malformation in hand and upper extremity without tourniquet application.

The objective of this report is to present a case of hand burn linear contracture release performed under local anesthesia. It also introduces the one-per-mil tumescent solution consisted of 0.2% lidocaine and 1:1.000.000 epinephrine as a local anesthesia formula, which has the potential of providing adequate anesthesia as well as hemostatic effect during surgery of the hand without tourniquet. The surgery was performed on a 19 year-old male patient with multiple thumb and fingers flexion linear contracture for 105 minutes without any obstacle. The patient did not complain any pain and discomfort during the procedure; while bloodless operative field was successfully achieved. At four-month follow up, the patient could fully extend his thumb, middle and ring finger, while the index was limited by 10° at the DIP joint. Overall, the patient was satisfied with the outcome.

Taking a Harder Look at Anesthesia.

Using gold plated electrodes, inserted into the rat's head above the dura of the left and right parietal cortex, we recorded EEG during deep and shallow anesthesia with either pentobarbital (PB) or ketamine-xylazine (KX). The fluctuations in time series were then analyzed using wavelet transforms and the spectral power was determined within 7 frequency intervals (slow wave 2, S2, 0.0067–0.0167 Hz; slow wave 1, S1, 0.02–0.19 Hz; δ, 0.2–3.9 Hz; θ, 4–7.9 Hz; α, 8–12.9 Hz; β, 13–24.9 Hz and γ, 25–34.9 Hz). In addition, the coupling strengths between individual oscillatory components during deep and shallow anesthesia were evaluated for both anesthetics. We show specific changes for both anesthetics indicating that during deep anesthesia PB reduces high and low frequency activity (0.2–35 Hz) and enhances coupling especially between δ, θ and α waves, while KX reduces low frequency activity (0.005 to 0.2 Hz) and enhances coupling between frequency waves α, β and γ. Our results, using two anesthetics known to block different ion channels, provide an insight into brain dynamics and could have wide implications in creating biomarkers for detecting various neurophysiological modifications, such as in Alzheimer and Parkinson's disease or Autism spectrum disorder, as well as in providing more realistic models of brain dynamics.

A male, 9-year-old Bengal tiger (Panthera tigris tigris) with low serum T3 and T4 concentration died one day after recovering from anesthesia for routine health evaluations. Post-mortem radiographic findings revealed a distended stomach and loops of bowel in the thoracic cavity. At necropsy, severe displacement of abdominal viscera into the thoracic cavity through the esophageal hiatus was accompanied by rupture of the diaphragm, volvulus of abdominal viscera, strangulation of the intestines, and collapse of the lung. Microscopically, there were marked myodegeneration and myonecrosis of the diaphragm and varying degrees of congestion in the displaced organs. The thyroid had variably sized and shaped thyroid follicles with slight lymphocytic infiltration in the interstitium. The present case suggests that a hiatus hernia may be one of the life-threatening post-anesthesia complications in tigers with hypothyroidism.

The lifetime of the asymmetric fundamental stretching 2218 cm^-1 vibration of the anesthetic gas nitrous oxide (N₂O) dissolved in octanol and olive oil is reported. These solvents are model systems commonly used to assess anesthetic potency. Picosecond time-scale molecular dynamics simulations have suggested that protein dynamics or membrane dynamics play a role in the molecular mechanism of anesthetic action. Ultrafast infrared spectroscopy with 100 fs time resolution is an ideal tool to probe dynamics of anesthetic molecules on such timescales. Pump-probe studies centered at the peak of the vibrational band yield a lifetime of 55 ± 1 ps in olive oil and 52 ± 1 ps in octanol. The similarity of lifetimes suggests that energy relaxation of the anesthetic is determined primarily by the hydrophobic nature of the environment, consistent with models of anesthetic action. The results show that nitrous oxide is a good model system for probing anesthetic-solvent interactions using nonlinear infrared spectroscopy.

It has been proposed that an action potential going through a nerve cell is not merely an electrochemical phenomenon, but also involves a traveling wave of compression and partial freezing of the lipid bilayer membrane. Below we present the results of experiments that are intended to discriminate between the electrochemical and the thermodynamic mechanism. We find that a nerve that is affected by an anesthetic can nevertheless reach the same compound action potential as an unaffected nerve when it receives a higher stimulus voltage. The result is hard to reconcile with the electrochemical Hodgkin–Huxley model and consistent with the thermodynamic mechanism.

In the late 1980s and early 1990s, Dr. Britton Chance and his colleagues, using picosecond-long laser pulses, spearheaded the development of time-resolved spectroscopy techniques in an effort to obtain quantitative information about the optical characteristics of the tissue. These efforts by Chance and colleagues expedited the translation of near-infrared spectroscopy (NIRS)-based techniques into a neuroimaging modality for various cognitive studies. Beginning in the early 2000s, Dr. Britton Chance guided and steered the collaboration with the Optical Brain Imaging team at Drexel University toward the development and application of a field deployable continuous wave functional near-infrared spectroscopy (fNIR) system as a means to monitor cognitive functions, particularly during attention and working memory tasks as well as for complex tasks such as war games and air traffic control scenarios performed by healthy volunteers under operational conditions. Further, these collaborative efforts led to various clinical applications, including traumatic brain injury, depth of anesthesia monitoring, pediatric pain assessment, and brain–computer interface in neurology. In this paper, we introduce how these collaborative studies have made fNIR an excellent candidate for specified clinical and research applications, including repeated cortical neuroimaging, bedside or home monitoring, the elicitation of a positive effect, and protocols requiring ecological validity. This paper represents a token of our gratitude to Dr. Britton Chance for his influence and leadership. Through this manuscript we show our appreciation by contributing to his commemoration and through our work we will strive to advance the field of optical brain imaging and promote his legacy.

Injectable oxygen delivery is an emerging technology that presents an opportunity for improved patient care in a number of medical disciplines. Here, we report on the fabrication and characterization of novel protein-encapsulated oxygen microbubbles (OMBs) designed for intravenous injection. The nanothick albumin encapsulation provided OMBs small enough for transcapillary passage: 99% of the microbubbles were less than 3-μm diameter and less than 1% of the oxygen was encapsulated in microbubbles greater than 8-μm diameter. The protein OMBs were remarkably stable, losing less than 40% of the encapsulated gas over 12 days. Upon injection into an oxygen-depleted saline solution, the protein OMBs rapidly equilibrated by releasing their oxygen core. These results indicate that protein microbubbles may serve as a suitable platform for direct injection of bioactive and therapeutic gases.

Early active mobilization after hand surgery is extremely important for preventing scar tissue and adhesion. We examined four patients for whom continuous peripheral nerve blocks (CPNB) were used during and after hand surgery. This method was used for three median nerves and one ulnar nerve. A 2-cm incision was made at distal one-third of the forearm with local analgesia. The catheter tip was placed in the distal one-fourth of the forearm, and the hand surgery was begun. Early active mobilization and the self-rehabilitation exercise started immediately after the operation. The VAS scores during exercise were 0–2 (mean: 1.3); pain was controlled sufficiently. Regarding ROM, excellent results were obtained for tenolysis, with good results for arthrolysis. No infection or postoperative nerve compression was found. This method, using CPNB with a portable infusion pump, is effective and safe for use at home for postoperative pain control.

Background: Wide Awake Local Anesthesia No Tourniquet (WALANT) uses a mixture of lidocaine and epinephrine for anesthesia and has found great success in hand surgery. At the Philippine Orthopedic Center (POC), we still use local anesthesia along with a tourniquet which gives the patient pain and discomfort at the tourniquet site. This study aims to determine perioperative and post-operative pain, intraoperative bleeding and immediate clinical outcomes of patients using WALANT for surgical anesthesia for carpal tunnel release.

Methods: A case series of all patients who underwent carpal tunnel release under WALANT from April 2016 to September 2016 is presented. Those with concomitant trigger finger and de quervain disease which required release on the affected hand were also included. A tourniquet was on standby in case of uncontrollable bleeding. Intraoperative bleeding, pain NRS scores, and return to daily activity were noted.

Results: Thirteen patients were included in the study; 3 were male, 10 were female. Mean age was 58 years, Mean surgical time was 15 minutes. Twelve were reported to have “some bleeding” and one was reported to have “bleeding but was still manageable”. None of the surgeries were totally bloodless or had too much bleeding that necessitated a tourniquet. Pain NRS scores during injection of local anesthesia had a mean of 2. None of the patients felt pain during and immediately after the surgery. Average time return to daily activity was 6 days. No complications were noted.

Conclusions: Patients included in the study who underwent carpal tunnel release under WALANT did not experience pain associated with a tourniquet. Visualization of the field was adequate enough for the surgeons to do the surgery without the need for a tourniquet and with no associated complications.

This paper develops a computational framework to classify different anesthesia states, including awake, moderate anesthesia, and general anesthesia, using electroencephalography (EEG) signal. The proposed framework presents data gathering; preprocessing; appropriate selection of window length by genetic algorithm (GA); feature extraction by approximate entropy (ApEn), Petrosian fractal dimension (PFD), Hurst exponent (HE), largest Lyapunov exponent (LLE), Lempel-Ziv complexity (LZC), correlation dimension (CD), and Daubechies wavelet coefficients; feature normalization; feature selection by non-negative sparse principal component analysis (NSPCA); and classification by radial basis function (RBF) neural network. Because of the small number of samples, a five-fold cross-validation approach is used to validate the results. A GA is used to select that by observing an interval of 2.7s for further assessment. This paper assessed superior features, such as LZC, ApEn, PFD, HE, the mean value of wavelet coefficients for the beta band, and LLE. The results indicate that the proposed framework can classify different anesthesia states, including awake, moderate anesthesia, and general anesthesia, with an accuracy of 92.07%, 96.18%, and 93.42%, respectively. Therefore, the proposed framework can discriminate different anesthesia states with an average accuracy of 93.89%. Finally, the proposed framework provided a facilitative representation of the brain’s behavior in different states of anesthesia.

In this chapter, the humane use of animals in surgical research is described, with reference to Russell and Burch's The Principles of Humane Experimental Technique (1992) — commonly known as the 3R's of replacement, reduction, and refinement — as well as the ethical need for researchers to justify the experiment and take responsibility for the well-being of animals in their care. The basic role of animal ethics committees is also discussed. The chapter then describes in practical terms the preparation of the experimental animal for surgery; the techniques for anesthesia, including knock-down, intubation, and maintenance; and the drugs used for premedication before anesthesia, maintenance of anesthesia, and, most importantly, pre-emptive and postoperative pain relief. The monitoring of the experimental animal under anesthesia and during recovery is also discussed.

The most important clinical application of acupuncture is for the control of pain, particularly when the pain arises from musculoskeletal pathologies or conditions related to the head and neck regions. Acupuncture experts have accumulated vast experiences on the treatment of pain of different nature and affecting different regions of the body. Before discussing the practical aspects of acupuncture for pain control, it is important to understand the physiological basis of the pain control mechanisms. Neurophysiology is still a developing fi eld, and the complexity of the neuro-anatomy and complicated functional pathways of sensory conduction and interpretation have limited the depth of the knowledge needed for the explanation of acupuncture analgesia. This chapter provides the information already established concerning the different parts of the central and peripheral nervous systems involved in pain perceptions and control, the neurotransmitters involved, the regulatory pathways, physiological theories and influences of electrical stimulation.

As our knowledge of reductionist details of living systems continues to grow, the gap in understanding life and consciousness remains wide. Progress has been made, e.g., biological organisms are seen as complex hierarchical amalgamations of elements interacting in self-similar, “scaleinvariant” patterns within and across spatio-temporal scales (“1/f”). But the mechanism for trans-scalar communication is unknown, as are the origin and foundation, i.e., the “bottom floor” of scale-invariant systems in biology. Here, we describe scale-invariant hierarchies in brain and living organisms in general, originating in a biomolecular “quantum underground” pervading neurons, glia and all living cells, most specifically within cytoskeletal microtubules. The quantum underground is a non-polar solubility phase composed largely of π-electron resonance clouds of aromatic amino acids, similar to pi-resonance arrays mediating quantum coherence in photosynthesis proteins. In the brain, the quantum underground is identified as the origin of consciousness by the Meyer-Overton correlation, showing where anesthetics act to erase consciousness while sparing non-conscious brain activities. Evidence points to anesthetics acting to dampen quantum dipole oscillations in the “Meyer-Overton quantum underground” within brain neuronal microtubules. These quantum dipole oscillations are seen as the “inward apex,” the origin of scale-invariant processes in consciousness and life.

The nature of consciousness, the mechanism by which it occurs in the brain, and its ultimate place in the universe are unknown. We proposed in the mid 1990's that consciousness depends on biologically “orchestrated” coherent quantum processes in collections of microtubules within brain neurons, that these quantum processes correlate with, and regulate, neuronal synaptic and membrane activity, and that the continuous Schrödinger evolution of each such process terminates in accordance with the specific Diósi-Penrose (DP) scheme of “objective reduction” (“OR”) of the quantum state. This orchestrated OR activity (“Orch OR”) is taken to result in moments of conscious awareness and/or choice. The DP form of OR is related to the fundamentals of quantum mechanics and space-time geometry, so Orch OR suggests that there is a connection between the brain's biomolecular processes and the basic structure of the universe. Here we review Orch OR in light of criticisms and developments in quantum biology, neuroscience, physics and cosmology. We also introduce novel suggestions of (1) beat frequencies of faster Orch OR microtubule dynamics (e.g. megahertz) as a possible source of the observed electroencephalographic ("EEG") correlates of consciousness and (2) that OR played a key role in life's evolution. We conclude that consciousness plays an intrinsic role in the universe.