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At least 955 records · Page 53Linked to original sources
PubMed2005

Conscious off pump coronary artery bypass surgery--an audit of our first 151 cases.

PURPOSE: An audit of our first 151 cases of conscious off pump coronary artery bypass (COPCAB) surgery with epidural anesthesia as sole anesthetic. METHODS: Patients underwent conscious off pump coronary artery bypass (OPCAB) surgery using high thoracic epidural anesthesia. The epidural catheter was inserted on the day before the surgery. RESULTS: There were 118 male and 33 female patients. The incision was via midsternotomy except in 3 patients. Single graft was performed in 25 patients, double in 61, triple in 46, quadruple in 19. Twenty-nine patients developed pneumothorax. Three patients required conversion to general anesthesia. In one patient cardiopulmonary bypass (CPB) was instituted. There was no mortality in the group. CONCLUSION: Our experience shows that conscious OPCAB surgery can be performed safely in selected patients.

Anesthesia, Epidural↗
PubMedDate not supplied

Traumatic axolemmal and cytoskeletal derangement in myelinated axons of human oedematous cerebral cortex and loss of consciousness. An electron microscopic study using cortical biopsies.

Cortical biopsies of 7 patients with clinical diagnosis of severe head trauma and complicated brain trauma with subdural and epidural hematoma, and loss of consciousness were examined with the transmission electron microscope to study axolemmal and cytoskeletal damage in myelinated axons. Granular disintegration of microtubules and misaligned and fragmented neurofilaments, and fragmentation of axolemmal membrane were observed in most patients studied. In some cases a differential response characterized by increased number of neurofilaments and decreased number or disappearance of microtubules was found. In few cases apparently intact microtubules coexisting with fragmented ones were found. These findings are discussed in relation with traumatic brain edema and associated anoxic-ischemic conditions, the Hameroff-Penrose hypothesis relating microtubules and consciousness, and the existing and contemporary knowledge on neural correlates of consciousness.

Adolescent↗
PubMed2005

Experimentally manipulating the effects of involuntary conscious memory on a priming task.

Recent studies showed that involuntary conscious memory can enhance priming in implicit tasks. However, because the results of these studies were based on post hoc selection methods in which subjects were assigned to conditions (aware or unaware) based on their responses on a posttest questionnaire, it is possible that subject selection effects may have influenced the results. The present study used a novel method that experimentally manipulated the effects of involuntary conscious memory on a word stem task. This was accomplished by inducing the experience of word recollection in one test condition while inhibiting it in another. This study showed that subjects who experienced word recollection showed significantly higher rates of priming than those who did not. The results represent the first purely experimental demonstration of involuntary conscious memory's ability to affect priming on implicit tasks.

Awareness↗
PubMedDate not supplied

[Geoelectromagnetic field and consciousness quantum].

A physically grounded model of consciousness quantum associated with free radical spins of the biomembranes is proposed. Essentially, is the consciousness quantum physically valid as a fundamental constant of 10(40) spins? According to our concept, consciousness quantum transduction is possible in geoelectromagnetic field of 0.5 erg by a 1.4 MHz electromagnetic wave under conditions of magnetic resonance. At the same time, the presented rationale requires further consideration.

Consciousness↗
PubMed2006

[Case of Graves' disease presenting only with rapid consciousness disturbance].

A 79-year-old woman was admitted to our hospital because of forgetfulness for a month followed with rapid development of consciousness disturbance. After admission, the depressed consciousness level fluctuated but continued for more than a month. Thyroid function tests showed increased free T3 and T4 level, lowered level of TSH, and increased anti-TSH receptor antibody titer. A diagnosis of Graves' disease was made but we could find none of thyrotoxic manifestations such as goiter, exophthalmos, tachycardia, high body temperature, or sweating. Administration of thiamazole rapidly improved her consciousness level. It should be kept in mind that hyperthyroidism in elderly could present solely with psychoneurologic symptoms or consiousness disturbance.

Aged↗
PubMed1991

Cardiovascular effects of adenosine A2 agonists in the conscious spontaneously hypertensive rat: a comparative study of three structurally distinct ligands.

The hemodynamic responses to 5'-N-ethylcarboxamide adenosine (NECA), a nonselective adenosine agonist, were compared to those elicited by the sodium salt of 2-[p-(2-carboxyethyl)phenethylamino]-5'-N-ethylcarboxamido adenosine (CGS 21680C) and N6-2-(3,5-dimethoxyphenyl)-2-(2-methylphenyl)-ethyl adenosine (CGS 24012), two structurally dissimilar selective A2 agonists in conscious spontaneously hypertensive rats (SHR). Dose-related reductions in mean arterial pressure occurred after bolus administration of NECA, CGS 21680C and CGS 24012. Dose-dependent tachycardia was seen with both CGS 21680C and CGS 24012, whereas NECA produced a biphasic response on heart rate. At high doses (3 and 10 micrograms/kg), NECA evoked an immediate and dramatic fall in heart rate, followed by a more gradual and long-lasting tachycardia. At equihypotensive doses, both CGS 21680C and CGS 24012 produced significant increases in cardiac output, but NECA had no effect. Although each of the adenosine agonists reduced total peripheral resistance, the greatest change was produced by CGS 21680C. Hindquarter, renal and mesenteric vascular resistances were significantly reduced by both CGS 21680C and CGS 24012, whereas only mesenteric vascular resistance was reduced with NECA. CGS 24012 reduced renal vascular resistance to the greatest extent and produced a concomitant significant increase in renal blood flow. Marked elevation in plasma renin activity occurred with CGS 24012 and CGS 21680C, whereas no change was seen after NECA. The hemodynamic responses to NECA, CGS 21680C and CGS 24012 were significantly reduced by the adenosine antagonist, 8-(p-sulfophenyl) theophylline, suggesting that these agents act through stimulation of adenosine receptors in the conscious SHR. Furthermore, blockade of the beta adrenergic receptor with metoprolol (1 mg/kg, i.v.) significantly attenuated the increase in heart rate produced by NECA, CGS 21680C and CGS 24012. The cardiovascular pattern of responses to the two selective A2 agonists, CGS 21680C and CGS 24012, are distinct from those of NECA, the nonselective adenosine agonist. The responses to both CGS 21680C and CGS 24012 indicate that systemic vasodilation, with resultant cardioexcitation and stimulation of renin release, are the predominant hemodynamic effects of selective A2 agonists in the conscious SHR. In contrast, the cardiovascular effects produced by NECA are mediated by activation of both A1 and A2 receptors.

Adenosine↗
PubMed1991

[The correlation of consciousness level and the concentration of CSF ammonia in a patient with adult-type citrullinemia].

A 29-year-old man who had a taste for peanuts frequently showed abnormal behaviors. Physical examination revealed consciousness disturbance associated with flapping tremor, hypotonus in the extremities, and hypoactive deep tendon reflexes. Laboratory examination showed hyperammonemia with mild liver injury. A level of serum citrulline was 14 times higher than the upper limit of normal. A diagnosis of type 2 citrullinemia (Seheki et al) was established by the decreased argininosuccinate synthetase (ASS) in liver with low amount of ASS protein and normal kinetic properties. Diurnal fluctuation of consciousness level in this patient was not correlated with the concentration of ammonia in serum, but with that in cerebrospinal fluid. Main metabolic pathway of ammonia in brain is considered to be localized in astrocytes which have receptors for glucocorticoids. Glucocorticoids induce additional glutamine synthetase activity. Circadian rhythm of cortisol level might play a role in diurnal fluctuation of consciousness level in patients with citrullinemia.

Adult↗
PubMed1991

[Auditory brain stem response in patients with consciousness disturbance].

To investigate the prognosis for patients with consciousness disturbance, we recorded auditory brain stem response (ABR) in 35 patients with primary or secondary brain damage. For patients with secondary brain damage, the first ABR recorded after admission could be used not only to differentiate consciousness level but also to predict prognosis. However, for the patients with primary brain damage, the first ABR could not be used for either differentiating consciousness level or predicting prognosis. In addition, in two patients with secondary brain damage, the series of ABR recordings indicated that brain stem damage was reversible.

Adolescent↗
PubMedDate not supplied

[The effect of the level of consciousness on the spatial organization of cortical activity in mental processes].

In the present study the influence of the level of consciousness on spatial organization of the cortical functional activity in human psychic processes was investigated. For regulation of the level of consciousness models were used of hypnotic analgesia, automatization of intellectual actions and mental activity in hypnotic state. Evaluation of the mosaic of the cortical activity was made by parameters of spatial synchronization of the potentials with topographic mapping of crosscorrelation, spectral and coherent-phasic EEG characteristics. The obtained data allow to conclude about special role of the frontal areas of the left hemisphere in the process of realization of information. It has been shown that one of the main functions in neurophysiological structure of consciousness is the selection of signals according to dominating motivation. The frontal areas of the left hemisphere control the degree of inclusion of foci of increased activity, specific and non-specific for each type of activity, and possibly, regulate the way of transformation of the information.

Adolescent↗
PubMedDate not supplied

[Levels of consciousness and levels of activation].

In the paper Pavlov's idea is used about "the bright spot of consciousness" as a zone of increased excitability which moves over the cerebral cortex. Zone of increased activation is revealed migrating from the frontal parts of the left hemisphere to the occipital parts of the right hemisphere. By means of various methods (record of amplitude and latency of the visual evoked responses, frequency and amplitude of the dominant rhythm, spectral-coherent analysis of the electroencephalogram) the activation of focus in the cerebral cortex was singled out, which moved, depending on the novelty, complication and degree of automatization of the task, from the frontal parts of the left hemisphere to the occipital parts of the right hemisphere. A parallel is drawn between Pavlov's hypothesis on the focus of consciousness as foci of increased brain activity, and revealed foci of activation. The conclusion is made about fluctuations of consciousness level as a factor which is in the basis of activation focus migration.

Adolescent↗
PubMed1990

A new method for hemodynamic and echocardiographic assessment of conscious dogs: comparison with thiopental-morphine anaesthesia.

A method allowing assessment of cardiac structure and function in the conscious dog using readily available instrumentation is desirable and should provide physiologic advantages when compared to anaesthesia. Accordingly, we studied 19 dogs (22 +/- 2.5 kg), using two-dimensional echocardiographic and Swan-Ganz and femoral artery catheterization; ten were conditioned to permit conscious studies and nine received anaesthesia. Dogs receiving anaesthesia were induced with intravenous thiopental (16 +/- 4 mg/kg), followed by a maintenance dose (7 +/- 1 mg/kg/h) plus morphine sulphate (213 +/- 5 micrograms/kg/h). Cardiac index, mean blood pressure, and systemic vascular resistance were similar between groups. However, anaesthesia as compared to conscious studies resulted in a marked tachycardia (147 +/- 30 bpm, vs 98 +/- 19 bpm, p less than 0.0005), significantly lower right atrial pressure (5 +/- 2 mmHg vs 8 +/- 2 mmHg, p less than 0.05), and a trend towards a lower pulmonary capillary wedge pressure (6 +/- 5 mmHg vs 9 +/- 3 mmHg). Simultaneous echocardiography showed left ventricular diastolic cross sectional area to be smaller in the anaesthesia group (8.5 +/- 1.7 cm2 vs 10.4 +/- 1.5 cm2, p less than 0.05); however, ejection fraction in the two groups was similar. Velocity of circumferential fiber shortening (Vcf), normalized for heart rate and preload, was significantly lower in the anaesthetised dogs (0.63 +/- 0.22 circ/sec vs 0.89 +/- 0.26 circ/sec, p less than 0.05); this decline in Vcf, in association with a lower systolic wall stress (85 +/- 29 10(3) dynes/cm2 vs 119 +/- 23 10(3) dynes/cm2, p less than 0.05) indicates that thiopental-morphine anaesthesia depresses contractility.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia↗
PubMed1988

[Metrizamide encephalopathy in a child with hydrocephalus--effects of L-threo-DOPS on persistent disturbance of consciousness and L-dopa on extrapyramidal symptoms].

This report describes a case of metrizamide encephalopathy with persistent disturbance of consciousness and extrapyramidal symptoms. These two conditions have rarely been reported among the various adverse effects of metrizamide. An 11-year-old girl had been in almost good health until she was ten years old, at which time she received a ventriculo-peritoneal shunt operation, suffering from hydrocephalus of unknown etiology. At the age of eleven, she was admitted to our hospital due to hydrocephalus recurrence. She was examined by metrizamide shunt-gram (1200 mg iodide/4 ml). On the next day, she became drowsy. The CT scan disclosed the periventricular penetration of metrizamide into the medial part of the thalamus and the caudate nucleus. Thirteen days later, disturbance of consciousness continued, and extrapyramidal symptoms, that is, rigo-spasticity and postural tremor, were observed. Oral administration of L-threo-DOPS, the direct precursor of noradrenaline, was effective against the persistent disturbance of consciousness and L-DOPA was effective against the extrapyramidal symptoms. She soon recovered almost to normal and no neurological deficit remained. We thus conclude that the CT scan findings and effects of L-threo-DOPS and L-DOPA suggest that metrizamide encephalopathy in this case were respectively due to its periventricular penetration into the medial part of the thalamus and the caudate nucleus, and the resultant deficiency of the ascending noradrenergic reticular activating system and the nigrostriatal dopaminergic system.

Basal Ganglia Diseases↗
PubMed1988

Determination of the "time of useful consciousness" (TUC) in repeated exposures to simulated altitude of 25,000 ft (7,620 m).

Time of useful consciousness (TUC) was determined in 17 subjects exposed twice to 25,000 ft (7,620 m) in an altitude chamber. The criterion for TUC determination was inability to add two-digit numbers correctly. Median values of TUC were 267.5 seconds (s) in the first exposure and 240 s in the second. The intraindividual variability between the two exposures was 40.6 s. The probability of remaining in "useful" consciousness as a function of time at 25,000 ft (7,620 m) was similar in both exposures. The need for a more scientific approach towards the determination of time of useful consciousness in simulated high altitudes is raised.

Adult↗
PubMed1987

Memory and consciousness.

During the first few years of his analysis Mr Smith had no mental or visual memories. He had body memories in so far as his body both looked like a baby, and behaved in a baby-like way on the couch. There were no words to describe the baby or his environment. He was a baby who could not think or communicate verbally. He made strange noises, but each day was the same as the last. There were no other patterns of behaviour. For the first three years the analysis consisted mainly in the patient coming to sessions and leaving them and starting again the next day; in the analyst trying not to make sense of the content of the words that were spoken, but in trying to catch some sense or feeling from the movements of his body and the sounds that he made. He did not use the words 'I' or 'you' in his sessions. His conscious thoughts were derived from other peoples' consciousness and did not link up with his own perceptions. After about three years of analysis the patient started to remember his sessions. Whereas before he seemed half awake and half asleep, half conscious and half unconscious, he became awake enough to perceive.

Consciousness↗
PubMed1987

First-pass radionuclide ventriculography in conscious dogs.

Trained, chronically instrumented, conscious dogs were used to study the function of the left ventricle by first-pass radionuclide ventriculography (RNV). Six dogs were trained prior to a sterile left thoracotomy, where a left atrial catheter was implanted. After recovery of four days RNV was carried out by injecting a bolus of technetium-99m-DTPA via the catheter to the left atrium. The data was collected for 12 s to a computer by frame rate of 20 frames/s from left lateral view of the dog. The experiments were performed both in four-leg standing and in 60 degrees head-up tilted positions. The measurements were done with two injection volumes (0.25 and 1.0 ml/kg) to study the effect of volume on the results. The body position had effect on left ventricular end-diastolic and stroke volumes, whereas ejection fraction remained unchanged. In comparison of the two injection volumes a minor difference was found in left atrial emptying, while the differences in left ventricular function were non-significant. In spite of training and careful standardization of experimental procedures, relatively high individual variation between animals was found in most parameters studied. The first-pass RNV method proved to be promising for measuring the left ventricular function in conscious dogs. Although the left atrium has reflectory tachycardic potential to distension, the volumes used for RNV did not affect the results. The left ventricular adaptation to head-up tilting in conscious dogs seems to consist mainly of decrease in left ventricular volume without significant effect on ejection fraction.

Animals↗
PubMedDate not supplied

[Intercentral correlations in the cerebral cortex according to the EEG coherence index after restoration of consciousness and speech following prolonged coma].

Power spectra and coherence function of EEG of various cortical areas of both hemispheres were analyzed in 9 patients with extremely protracted loss of consciousness. Five patients were in the state of posttraumatic apallic syndrome lasting for more than 4 years in one patient, and 4-9 months with successive lethal outcome in 4 patients. One patient for more than 2 years was in a state of areactivity to external signals. In 3 patients the process of recovery of consciousness and speech began in 1-2 months. At the apallic syndrome, only low-frequency EEG components were present in spectrograms, and the values of coherence function were sharply decreased. With recovering consciousness and speech, a gradual appearance of alpha-activity was observed as well as an increase of coherence values at the frequency of the alpha-rhythm. The recovery of intercentral EEG relations in the motor-verbal cortical area was shown to play a special role in further normalization of connections in the cerebral cortex.

Brain Injuries↗
PubMed1985

Altered states of consciousness profile: an Afro-centric intrapsychic evaluation tool.

In an effort to develop an Afro-centric intrapsychic evaluation tool, the Community Mental Health Council, Inc., Altered States of Consciousness Research Team, developed a structured interview used to quantify and qualify the 17 states of consciousness(1) that occurred in black control, precare, and aftercare subjects. Differences were noted in the three groups as to the incidence, prevalence, and quality of the various states of consciousness. It was also noted that the profile obtained from the interviews yielded a sharp clinical picture of the subjects' total intrapsychic propensities.

Africa↗
PubMed1979

Urticaria pigmentosa---change in conscious state associated with rise in plasma histamine levels.

The case is described of a 42-year-old man with urticaria pigmentosa and documented systemic mastocytosis who had 2 episodes of loss of consciousness, headache, nasal stuffiness and faecal incontinence, following a swim in a river. Under controlled conditions the patient was subjected to immersion of the right hand to icewater for a period of 2 minutes, followed by 2 minutes of strenuous exercise. Similar symptoms involving change in conscious state were evoked with accompanying rises in plasma histamine levels. These findings suggest that histamine is at least one of the major mediators of the change in conscious state that is reported rarely in these patients and draws attention to the neurological facets of this rate disorder.

Adult↗