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At least 973 records · Page 54Linked to original sources
PubMed1983

Biphasic blood pressure response to angiotensin II in the conscious rabbit: relation to prostaglandins.

The injection of a large bolus of angiotensin II causes a biphasic blood pressure response in the conscious rabbit. To investigate contribution of prostaglandins (PGs) to the depressor phase of the blood pressure response, we studied the blood pressure effect of i.v. bolus injections of angiotensin II before and after the administration of an inhibitor of cyclooxygenase, indomethacin or sodium meclofenamate (10 mg kg-1), and in relation to associated changes in the plasma concentration of immunoreactive PGs. In conscious rabbits, angiotensin II (0.05-5.00 microgram kg-1) produced a dose-related pressor response which at both 1.5 and 5.0 micrograms kg-1 was followed by lowering of blood pressure to below the preinjection level. Neither indomethacin nor meclofenamate affected the maximal rise in pressure produced by angiotensin II, but both cyclooxygenase inhibitors augmented the duration of the pressor phase and abolished the depressor phase of the hemodynamic response to angiotensin II at 1.5 to 5.0 micrograms kg-1. After administration of angiotensin II, 5 micrograms kg-1, the plasma concentration of 6-keto-PGF1 alpha increased (P less than .01) from 218 +/- 21 pg/ml by 221 and 235% during the pressor and the depressor phases of the blood pressure response, respectively. Increments in plasma 6-keto-PGF1 alpha correlated inversely with the duration of the pressor phase and directly with the maximal lowering of blood pressure during the depressor phase. Plasma levels of PGE2 and PGF2 alpha also were increased by the peptide but the increments were not correlated with any aspect of the blood pressure response. These data suggest that a mechanism involving PGs both curtails the pressor phase and mediates the depressor phase of the hemodynamic response to pharmacological doses of angiotensin II in the conscious rabbit.

6-Ketoprostaglandin F1 alpha↗
PubMed1983

[Types of consciousness disorders in stroke].

The peculiarities of consciousness disturbances in 289 patients with grave brain stroke were studied. Eight informative clinical syndromes, including the awakeness level, brain stem reflex functions as well as vegetative-visceral functions were described. Two levels and eleven corresponding to them phases of damaged consciousness were singled out. The scale of quantitative estimation of each phase of the consciousness damage was established for practical use by the computer method of plural step by step regression; dynamics of phases was shown also.

Adult↗
PubMed1980

[Effectiveness of parenteral administration of piracetam in acute and chronic consciousness disorders in cerebral arteriosclerosis].

The effectiveness of treatment with piracetam of 32 patients with acute and chronic consciousness disturbances caused by clinical syndromes of cerebrovascular disease (strokes, syndromes of dementia) was studied. The drug was administered in drip infusions in daily doses of 6 g for 10 days. A statistically significant improvement was obtained in the signs belonging to the syndrome of consciousness disturbances. No significant difference was observed in the power of action of the drug in acute and chronic consciousness disturbances.

Acute Disease↗
PubMed1982

Black intrapsychic survival skills: alteration of states of consciousness.

Psychiatry tends to be interested only in states of consciousness as they relate to psychopathology. In this paper the author presents the thesis that the ability to alter one's state of consciousness is in fact a survival skill useful in coping with the physiologic and psychologic effects of stress. Furthermore, he discusses techniques indigenous to black culture for altering states of consciousness and gives phenomenologic black transcultural evidence that black culture is quite sophisticated in the area of intrapsychic survival skills.

Black People↗
PubMed1981

Renal function during consciousness and anesthesia in sheep: effects of renal vasodilation by papaverine and acetylcholine.

Adult ewes were studied to determine the effects of barbiturate anesthesia on renal function and the natriuretic response to renal vasodilation by papaverine and acetylcholine. During a period of consciousness, renal blood flow, glomerular filtration rate, urinary Na excretion (UNaV) and arterial blood pressure were monitored. Renal blood flow was maximally increased by renal arterial infusion of papaverine or acetylcholine and changes in renal function were observed. The sheep were subsequently anesthetized and the experimental protocol was repeated. Barbiturate anesthesia resulted in statistically significant increases in glomerular filtration rate, UNaV and blood pressure. Calculated fractional Na excretion also increased significantly. During consciousness, maximal renal vasodilation by papaverine or acetylcholine did not increase UNaV or fractional Na excretion. During anesthesia, both papaverine and acetylcholine produced large increases in both UNaV and fractional Na excretion. These data indicate that renal vasodilation per se is not a sufficient condition to increase UNaV and suggest that barbiturate anesthetics can alter renal function in such a manner as to render drugs, which are not natriuretic during consciousness, effective natriuretic agents during anesthesia.

Acetylcholine↗
PubMed1995

Estimated noise distributions across stages of consciousness utilizing the Fsp quantification technique.

We used the Fsp technique to quantify the influence of changing stages of consciousness on the signal-to-noise ratio of the middle latency response (MLR). The MLR and polysomnographic activity were obtained from 10 subjects during a continuous 6-hour period. The Fsp statistic was applied to the MLR data in order to determine the number of scores above a specified criterion in each stage of consciousness and time window of analysis. Results demonstrated that the number of Fsp scores exceeding the criterion of acceptance decreased with increasing depth of sleep. The awake stage yielded the greatest proportion of scores above the criterion. The background noise data were analyzed separately. The distributions of noise differed as a function of stage of consciousness.

Adult↗
PubMed1995

Early restructuration of consciousness after traumatic coma.

Recovery of consciousness after acute brain injury is a remarkable phenomenon, yet, not completely understood. We describe the early clinical stages of recovery of consciousness in 48 selected patients by means of different items of the Glasgow Coma and Liege Coma Scales. Arousal, expressed by the stimulated opening of the eyes (E2) was correlated with the appearance of the localizing pain response (M5), with the capacity to obey commands (M6), with the opening of the eyes (E4) and with the blink reflex (R5). This study confirms the classical clinical sequence of arousal and recovery of consciousness characterized by the consecutive appearance of E2, R5, E4, M5 and M6. When the appearance of E2 and R5 are considered separately, we noticed a significant difference, suggesting different structural and functional brain recovery processes.

Adolescent↗
PubMed1995

The poisoned patient with altered consciousness. Controversies in the use of a 'coma cocktail'.

OBJECTIVE: In the assessment and management of the potentially poisoned patient with altered consciousness, the most consequential and controversial interventions occur during the first 5 minutes of care. In this review article, the risks and benefits of standard diagnostic and therapeutic interventions are presented to guide clinicians through this critical period of decision making. DATA SOURCES: Data for discussion were obtained from a search of English-language publications referenced on MEDLINE for the years 1966 to 1994. Older literature was included when pertinent. Search terms included poisoning, overdose, toxicity, naloxone, glucose, thiamine, and flumazenil. STUDY SELECTION: Only large trials were used for determinations of diagnostic utility and efficacy. Small trials, case series, and case reports were reviewed extensively for adverse effects. DATA EXTRACTION AND SYNTHESIS: Trials were reviewed for overall methodology, inclusion and exclusion criteria, sources of bias, and outcome. CONCLUSION: Analysis favors empirical administration of hypertonic dextrose and thiamine hydrochloride to patients with altered consciousness. Although rapid reagent test strips can be used to guide this therapy, they are not infallible, and they fail to recognize clinical hypoglycemia that may occur without numerical hypoglycemia. Administration of naloxone hydrochloride should be reserved for patients with signs and symptoms of opioid intoxication. Flumazenil is best left for reversal of therapeutic conscious sedation and rare select cases of benzodiazepine overdose.

Consciousness↗
PubMedDate not supplied

[Consciousness as a system of inner seeing].

The goal of the paper is to clarify the nature and mechanisms of functioning of human consciousness. It is assumed that the main specific feature, which distinguishes consciousness from other brain subsystems, is its ability to observe the content of its own memory. It demonstrates that cyclic information run in distributed neural structures with feedbacks may serve as a fundamental physiological mechanism of an inner scanning (awareness) system for information coming from outside. The area of location of consciousness in the brain is determined as a set of neural structures involved in cyclic information run processes. It is ascertained that the rehearsal procedure is a basis operational means of discursive thinking, imagination and reflexion.

Consciousness↗
PubMed1994

Intuition and consciousness.

Intuition represents an unconscious cognitive activity, the results of which become conscious at some point. Some recent nonpsychoanalytic explorations of cognition and consciousness are examined to illuminate our understanding of these processes and their relation to the psychoanalytic process. Our thesis is that intuition may be most usefully viewed as a form of unconscious pattern-matching cognition, which becomes conscious under certain conditions and which is only loosely related to primary process. A clinical example is given of the analyst's intuition to illustrate the initial ostensibly theory-free nature of the raw intuition and the subsequent theory-bound explorations of the intuitive conclusion. Implications for teaching and learning psychoanalysis are noted.

Adult↗
PubMed1994

The interaction of fentanyl on the Cp50 of propofol for loss of consciousness and skin incision.

BACKGROUND: We have previously demonstrated that the minimum alveolar concentration of isoflurane at 1 atm that is required to prevent movement in 50% of patients or animals exposed to a maximal noxious stimulus is markedly reduced by increasing fentanyl concentrations. Total intravenous anesthesia with propofol is increasing in popularity, yet the propofol concentrations required for total intravenous anesthesia or the interaction between propofol and fentanyl have not yet been defined. METHODS: Propofol and fentanyl were administered via computer-assisted continuous infusion to provide pseudo-steady-state concentrations and allow equilibration between plasma-blood concentration and their biophase concentration. For the induction of anesthesia patients were randomly allocated to receive propofol only or propofol plus fentanyl 0.2, 0.8, 1.5, 3.0, and 4.5 ng/ml. In each group patients were randomized to target propofol concentrations of 1.5-10 micrograms/ml. At 7 and 10 min arterial blood samples were taken for subsequent measurement of propofol and fentanyl concentrations. At 10 min loss of consciousness was assessed by the patients' ability to respond to a simple verbal command. Thereafter a new target concentration of propofol was entered to ensure loss of consciousness, and succinylcholine was administered to facilitate tracheal intubation. Patients were rerandomized to a new target concentration of propofol (1-19 micrograms/ml) until skin incision. Before skin incision and 1 min after skin incision, arterial blood samples were again obtained for subsequent measurement of fentanyl and propofol concentrations. At skin incision and for 1 min the patient was observed for purposeful movement. Only samples in which the pre- and poststimulus drug concentrations were within 35% of each other were included. The propofol blood concentration at which 50% or 95% of patients did not respond to verbal command (Cp50s and Cp95s, respectively) and to skin incision (Cp50i and Cp95i, respectively), were calculated by logistic regression. RESULTS: There were 56 evaluable patients for calculating the propofol Cp50s and 53 patients for calculating the propofol Cp50i. For propofol alone the Cp50s was 3.3 micrograms/ml and the Cp95s 5.4 microgram/ml. Increasing fentanyl concentrations reduced the Cp50s (P = 0.03), and increasing age decreased the Cp50s (P = 0.04). For propofol alone the Cp50i was 15.2 (95% confidence interval 7.6-22.8) micrograms/ml and the Cp95i 27.4 micrograms/ml. Increasing fentanyl concentrations markedly reduced the Cp50i (P < 0.01), with a 50% reduction in Cp50i produced by 0.63 ng/ml fentanyl. The propofol Cp50i was decreased by 63% with 1 ng/ml fentanyl and 89% by 3 ng/ml fentanyl. At higher fentanyl concentrations the decrease in Cp50i was proportionally less, demonstrating a ceiling effect. CONCLUSIONS: We defined the propofol concentration required for loss of consciousness and showed that it is reduced by increasing fentanyl concentration and by increasing age. The propofol concentration (alone) adequate for skin incision is high but is markedly reduced by fentanyl. A ceiling effect in the Cp50i for propofol is seen with fentanyl concentrations greater than 3 ng/ml.

Adult↗
PubMed1994

Hemodynamic and cerebral blood flow effects of cocaine, cocaethylene and benzoylecgonine in conscious and anesthetized fetal lambs.

We studied hemodynamic responses to cocaine and two metabolites, cocaethylene (CE) and benzoylecgonine (BE), in five conscious ewes and fetuses, which were chronically instrumented to measure maternal and fetal aortic pressures, uterine artery blood flow (Qutr) and fetal common carotid artery blood flow (Qcar) to estimate cerebral blood flow. Conscious ewes of 121 to 128 days' (mean, 124 days) gestation received 1.0 mg/kg i.v. of cocaine (n = 12 doses), CE (n = 14) or BE (n = 12) and responses were compared to seven additional ewes and fetuses at 115 to 127 days' (mean, 122 days) gestation each given one 1.0 mg/kg i.v. of cocaine dose while anesthetized with halothane. In conscious ewes, cocaine, CE and BE all caused maternal and fetal hypertension. Qutr decreased 31% after cocaine, increased 37% after CE and was unaffected by BE. Cocaine induced fetal hypoxemia; fetal arterial blood gas tensions were unaffected by CE or BE. Fetal Qcar was reduced 51% at peak effect by cocaine (57 +/- 8 to 28 +/- 6 ml/min) and 46% by CE (65 +/- 7 to 33 +/- 6 ml/min), and was unaffected by BE because of variable subject response, although all three drugs increased calculated fetal cerebral vascular resistance. The cocaine-induced changes were attenuated or abolished in anesthetized sheep. Fetal/maternal peak serum concentrations were 100% for CE and only 2% for BE; amniotic fluid concentrations of CE were 10-fold higher than both fetal and maternal serum concentrations. Cocaine and cocaine metabolites have important effects on maternal and fetal hemodynamics and fetal cerebral blood flow which, for CE and BE, are not dependent on decreased uterine blood flow or fetal hypoxemia.

Amniotic Fluid↗
PubMed1994

[Acute consciousness disorders and epilepsy from the psychiatrist's viewpoint].

Psychogenic loss of consciousness often leads to clinical situations where making decisions is difficult and psychiatric consultation becomes necessary. The function of the consultation/liaison-psychiatrist consists in rendering information from the psychosocial context comprehensible after establishing a first contact with the patient and his family and after the first psychiatric assessment. In a second step, the CL-psychiatrist then may make further recommendations how to deal with the patient, possibly not only in a patient-centered, but also team-centered manner. This article demonstrates a possible approach and differential diagnosis in the light of two clinical case reports. The theoretical part defines and classifies psychogenic loss of consciousness. It then deals with disorders of consciousness in epilepsy and the psychodynamics of psychogenic seizures as a subconscious expression of unbearable or unsolvable conflicts.

Consciousness Disorders↗
PubMed1993

[Postoperative disturbance of consciousness due to tumor emboli of the orifice of pulmonary artery].

We reported a case of an abrupt hypotension and hypoxemia which lasted more than 60 min due to emboli of tumor at the orifice of the pulmonary artery during operation. Although the emboli were removed under the cardiopulmonary bypass (CPB) and later the patient regained good respiratory and hemodynamic conditions, he had a disturbance of consciousness after the operation. We began oxygen hyperbaric therapy (OHP) from the 6th postoperative day under spontaneous ventilation. His consciousness improved quickly after the beginning of OHP. We conclude that OHP and CPB might be useful to treat the postoperative disturbance of consciousness due to hypotension and hypoxemia during operation.

Cardiopulmonary Bypass↗
PubMedDate not supplied

[Altered states of consciousness: theoretical models and concepts].

The main contemporary theoretical models and concepts of altered states of consciousness are reviewed. Analysis of the literature indicates that nowadays, psychology recognizes the existence of different levels of consciousness. The achievements of the psychology of consciousness are helpful in research, but they have a very limited application in psychiatric practice.

Arousal↗
PubMed1996

Information, consciousness, and health.

A 16-year empirical assessment of anomalous human/machine interactions provides strong evidence that consciousness can add information to otherwise random digital strings. A parallel program of remote perception studies establishes the inverse process: the anomalous acquisition of information about distant physical targets. Remarkably, neither of these extraordinary capabilities shows any dependence on either the distance or the time separating the participant from the target. The relevance of these consciousness abilities to human health follows from recognition that physiology entails myriad subtle information processes, all of which involve some degree of randomicity in their normal functions, and thus may be similarly influenced by conscious volition.

Consciousness↗
PubMed1996

[A patient with thyroid carcinoma who developed consciousness disturbance during acyclovir administration for herpes zoster].

A 69-year-old man developed confusion and disorientation, following intravenous administration of acyclovir for herpes zoster at the right C5 area. His consciousness was disturbed four days after the beginning of acyclovir therapy (daily dose: 500 mg, every 12 h), and the symptoms resolved two days after cessation of acyclovir. Neuroradiological examination revealed no intracranial abnormality, and the routine CSF examination was within the normal range of values except for a mild elevation of IgG (7.4 mg/dl). An electroencephalogram showed diffuse slow activities without paroxysmal waves on admission, but the findings of electroencephalograms were gradually normalized in parallel with the recovery of consciousness. Fever, signs of meningeal irritation, involuntary movement or renal dysfunction were not observed during the course of illness. Although the serum concentration of acyclovir was not elevated, we considered the adverse effects of acyclovir had resulted in his consciousness disturbance. Acyclovir is greatly useful for herpes simplex and varicella-zoster virus infections, and its complications are extremely rare. However, several reports described various neuropsychiatric side effects in patients receiving acyclovir. Most of such cases had an association with severe renal failure or malignant tumor; actually, an intense malignancy surveillance over our case revealed thyrogenic papillary adenocarcinoma without metastasis. The excretion of acyclovir is mainly through the kidney, so that the neurotoxicity of acyclovir in cases with renal insufficiency stems from its excessive accumulation in the body. In malignancy complicated patients, on the other hand, some authors surmised about the influences from the co-use of other neurotoxic drugs or radiation therapy, but reasons for such conditions remain obscure. The neuropsychiatric manifestation caused by acyclovir is an entity distinguishable from viral encephalitis, and a careful surveillance for malignancy is required in such cases.

Acyclovir↗
PubMedDate not supplied

[Activation of the brain and consciousness].

At least 3 levels of consciousness were identified within the stage B of sleep. Against the background of the increase in the alpha-rhythm amplitude, we observed an enhancement of voluntary and involuntary associations and increase in the flow of thoughts. The stage of "thought wandering" was accompanied by a considerable decrease in the alpha-rhythm regularity, a decrease in its frequency, and decrease in EEG coherence in all brain areas under study. At the stage of the "flat" EEG, the subjects experienced inhibition of mental processes ("empty heady"), their consciousness as if "falling down" to the lowest Ego level. The subjects were aware of the transition from one stage to another and could fix the stages. Thus, the results showed that subjective changes of levels of consciousness corresponded to different stages of transition from wakefulness to sleep which was objectively determined by the EEG.

Brain↗