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PubMed1995

Level of consciousness and age as prognostic factors in aneurysmal SAH.

The prognostic value of the level of consciousness and the patient's age for the outcome of aneurysmal subarachnoid haemorrhage (SAH) is studied in 74 patients admitted on day (D) 0 to D3 after aneurysm rupture. For the level of consciousness three groups of patients are compared: grade I+II (alert patients), grade III+IV (drowsy patients), and grade V (comatose patients). For the age, two groups are compared: patients aged under 50, and patients aged 50 and over. The timing of surgery was: D0-D3 51%, D4-D6 20%, D7 and later 18%, and No surgery 11%. The overall management results were: Good (satisfactory result) 43%, Fair (moderately disabled) 18%, Poor (severely disabled+vegetative survival) 19%, and Death 20%. The outcome was strongly related to the level of consciousness, the rates of Good result decreasing from 71% (grades I-II) to 14% (grades III-IV) and to zero (grade V), and the mortality rates increasing respectively from 5% to 14% and 61%. The relationship between outcome and age was less marked: 54% Good result under 50 and 30% over 50. Out of the Grade V group, 56% could be operated upon and 44% died before surgery. No patient from the other two groups died before surgery. The literature concerning the Grading Systems published so far and the various prognostic factors are discussed.

Aged↗
PubMed1990

Left ventricular effects of nicorandil in comparison with nitroglycerin in chronic conscious dogs.

Nicorandil is a new coronary vasodilator possessing beneficial properties. However, its detailed cardiovascular effects, especially on left ventricular (LV) preload, have not yet been fully elucidated. The purpose of this study was to assess the effects of nicorandil on LV hemodynamics in conscious dogs and to examine the mechanisms of its antiischemic action. Nine mongrel dogs were instrumented for instantaneous and continuous measurements of LV diameters, and aortic and LV pressures. The effects of nicorandil (0.2 mg/kg, intravenously) were compared with those of nitroglycerin (15 micrograms/kg, intravenously) in conscious dogs. Mean aortic pressure decreased similarly with both nicorandil and nitroglycerin (-20.1 +/- 3.1% vs. 21.6 +/- 2.8%, ns). Heart rate was elevated with both drugs. Both nicorandil and nitroglycerin significantly decreased LV systolic pressure to the same extent (-11.3 +/- 0.5% vs. -10.5 +/- 11.6%, ns). LV max dp/dt was not significantly changed by either drug. Although both nicorandil and nitroglycerin significantly increased fractional shortening, nicorandil had a greater effect on fractional shortening than nitroglycerin (20.0 +/- 3.0% vs. 10.2 +/- 2.3%, p less than 0.05). In this study, nicorandil, administered intravenously, had a salutary effect on cardiac function. LV end-diastolic diameter decreased with nicorandil and nitroglycerin (-6.5 +/- 1.5% vs. -12.6 +/- 2.6%, p less than 0.01), respectively. In conclusion, nicorandil decreased LV end-diastolic diameter in conscious dogs, indicating a decrease in venous return and preload of the heart. In addition, nicorandil decreased LV afterload to the same extent as nitroglycerin. The decrease in preload and afterload on the heart is thought to be one of the mechanisms of the antiischemic action of nicorandil.

Animals↗
PubMed1984

Measurement of arterial pressure-dimension relationships in conscious animals.

Currently, considerable clinical interest exists in the vasoactivity of large coronary arteries due to the prevalence of coronary vasospasm in mediating angina pectoris and even myocardial infarction. Although arterial elastic properties have been studied extensively in acute, anesthetized animal experiments and in vitro preparations, few data are available on these properties in conscious, chronically instrumented animals, where the complicating influences of anesthesia, recent surgery, and acute manipulation of the vessel are minimized. To study vascular smooth muscle in the conscious animal we modified the transit-time dimension measurement technique by designing smaller, higher frequency (7 MHz) transducers, and introducing electronic refinements to accurately measure smaller dimensions (2 mm minimum). We applied this technique to the left circumflex coronary (LCC) artery, along with arterial pressure measurements from either chronically implantable strain-gauge manometers, or microtip catheter manometers, to study dynamic compliance and vascular control mechanisms of these arteries for periods of months in conscious, chronically instrumented animals. Infusion of an alpha-adrenergic vasoconstrictor, methoxamine (50 micrograms/kg/min), caused sustained reduction in LCC diameter (9% +/- 2%) at a time when mean arterial pressure rose by 65% +/- 5% and heart rate and mean coronary blood flow (electromagnetic flow probe) were returned to control levels. Methoxamine induced a marked leftward shift in the pressure-diameter and stress-radius relationships, reducing vascular caliber for any given stress and pressure level. Moreover, smooth-muscle activation raised the effective incremental modulus (Einc) of the coronary arterial wall when compared at similar radii, but it reduced Einc when compared at similar stress or pressure levels. Thus, for any given arterial pressure level the Einc of the LCC artery wall can be reduced considerably by the enhanced smooth-muscle activation elicited by methoxamine. Nitroglycerin (25 micrograms/kg) induced an initial decrease in LCC diameter as pressure fell and LCC blood flow rose. However, dimensions then increased, reaching a maximum 5 minutes later, when LCC blood flow was reduced, and heart rate and left ventricular dP/dt were at control levels. The calcium-channel antagonist, nifedipine, caused similar early changes, with the increase in LCC caliber persisting for 46 +/- 5 minutes while LCC blood flow returned to control in 15 +/- 3 minutes.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1998

Effects of ventilation on hyaluronan and protein concentration in pleural liquid of anesthetized and conscious rabbits.

The hypothesis of this study is that pleural lubrication is enhanced by hyaluronan acting as a boundary lubricant in pleural liquid and by pleural filtration as reflected in changes in protein concentration with ventilation. Anesthetized rabbits were injected intravenously with Evans blue dye and ventilated with 100% O2 at either of two levels of ventilation for 6 h. Postmortem values of hyaluronan, total protein, and Evans blue-dyed albumin (EBA) concentrations in pleural liquid were greater at the higher ventilation, consistent with increases in boundary lubrication, pleural membrane permeability, and pleural filtration. To determine whether these effects were caused by hyperoxia or anesthesia, conscious rabbits were ventilated with either 3% CO2 or room air in a box for 6, 12, or 24 h. Similar to the anesthetized rabbits, pleural liquid hyaluronan concentration after 24 h was higher in the conscious rabbits with the hypercapnic-induced greater ventilation. By contrast, the time course of total protein and EBA in pleural liquid was similar in both groups of conscious rabbits, indicating no effect of ventilation on pleural permeability. The increase in pleural liquid hyaluronan concentration might be the result of mesothelial cell stimulation by a ventilation-induced increase in pleural liquid shear stress.

Anesthesia↗
PubMed2003

The effect of attentional cueing on conscious awareness of stimulus and response.

Attending to a cued location in space leads to faster reaction times when a stimulus is presented there. The reasons for this attentional effect, and its specific locus in the information-processing chain between stimulus and response, remain unclear. One suggestion is that attention speeds the conscious detection of stimuli. Surprisingly, this possibility appears not to have been tested directly. To resolve this question, we asked subjects to make simple responses to lateralised targets that followed either a valid, invalid or neutral cue, and to judge the perceived time of the target onset, or of their response, by delayed report of the position of a clock hand. Our results showed that only a small and non-significant part of the attentional effect is due to delayed conscious awareness of the stimulus. The greater part of the attentional effect is localised either subsequent to conscious detection of stimuli or occurs in a separate, parallel processing stream from that which generates the motor response.

Adult↗
PubMedDate not supplied

Safety of conscious sedation in interventional radiology.

PURPOSE: To identify rates of adverse events associated with the use of conscious sedation in interventional radiology. METHODS: In a 5-month period, prospective data were collected on patients undergoing conscious sedation for interventional radiology procedures (n = 594). Adverse events were categorized as respiratory, sedative, or major adverse events. Respiratory adverse events were those that required oral airway placement, ambu bag, or jaw thrust. Sedation adverse events were unresponsiveness, oxygen saturation less than 90%, use of flumazenil/naloxone, or agitation. Major adverse events were hypotension, intubation, CPR, or cardiac arrest. The frequency of adverse events for the five most common radiology procedures were determined. RESULTS: The five most common procedures (total n = 541) were biliary tube placement/exchange (n = 182), tunneled catheter placement (n = 135), diagnostic arteriography (n = 125), vascular interventions (n = 52), and other catheter insertions (n = 46). Rates for respiratory, sedation, and major adverse events were 4.7%, 4.2%, and 2.0%, respectively. The most frequent major adverse event was hypotension (2.0%). Biliary procedures had the highest rate of total adverse events (p < .05) and respiratory adverse events (p < .05). CONCLUSION: The frequency of adverse events is low with the use of conscious sedation during interventional procedures. The highest rates occurred during biliary interventions.

Adjuvants, Anesthesia↗
PubMed2005

[Independence, consciously accepted dependency, self-responsibility and shared responsibility as key categories of an ethical analysis of old age].

This contribution begins with a brief introduction into some seminal problems of ethics: the search for the essential being of things, the attitude of value consciousness in the context of ethical reflections, and the reflection on models of a 'good life' and on decisions as well as actions in significant moral situations. These introductory statements are illustrated by the example of stoic philosophy. In a second step, independence, consciously accepted dependency, self-responsibility and shared responsibility are discussed as highly significant categories for an ethical analysis of all ages. However these categories must be specified with reference to specific ages. In this contribution, such a specification is carried out for old age focussing on the particular relevance of the four categories for ethical analysis. In a third step, each of the four categories is discussed in detail in the context of basic ethical approaches. In this context, ethical analysis proceeds from the perspectives of the individual, the environment, and the society. Concerning the perspective of the society special interest is offered to societal models of good life in old age which might have an impact on the potential development of a pro-aging culture and shared responsibility in older people. Moreover, these models contribute to older people's ability to use the necessary means of support in cases of dependency and to consciously accept dependency.

Activities of Daily Living↗
PubMed2002

Endothelin-1 produces no renal vasoconstriction in conscious newborn lambs.

Experiments were carried out to investigate the effects of endothelin-1 (ET-1) on renal vascular tone during development under physiological conditions in conscious lambs. Renal blood flow (RBF), renal vascular resistance (RVR), mean arterial pressure (MAP), and heart rate (HR) were measured in conscious, chronically instrumented lambs aged approximately 1 week and 6 weeks before and after intra-arterial (i.a.) injection of 0, 100, 200, and 400 ng/kg body weight of ET-1. In addition, plasma levels of ET-1 were measured in 39 sheep aged 5-85 days. In 6-week-old lambs, i.a. injection of ET-1 was associated with a rapid dose-dependent decrease in RBF that resulted from a dose-dependent increase in RVR. In 1-week-old lambs, there was no renal vasoconstriction observed after ET-1 administration, even at the highest dose tested. In response to i.a. injection of ET-1 to 1-week-old and 6-week-old lambs, MAP increased and there was a concomitant decrease in HR; these effects were dose dependent but not age dependent. Plasma levels of ET-1 were 10.7+/-4.2 pg/ml at 5-10 days, and remained constant throughout the first 3 months of life in conscious sheep. We conclude that ET-1 is not a renal vasoconstrictor agent in the immediate newborn period, and that the effects of ET-1 on renal vascular tone appear to be developmentally regulated.

Aging↗
PubMed1976

Hypotensive responses following oral adminstration of beta-adrenoceptor blocking drugs to the conscious cat.

On oral administration, the non-selective beta-adrenoceptor blocking drugs (+/-)-bufuralol, (-)-bufuralol, propanolol, oxprenolol, pindolol and alprenolol produced hypotensive responses in the conscious cat; (+)-bufuralol was without effect. The selective beta-adrenoceptor blocking drugs practolol and atenolol had no effect on blood pressure but tolamolol elicited a hypotensive response. All the drugs tested reduced the tachycardia due to intravenous isoprenaline in the conscious cat; however, not all doses of these drugs reduced blood pressure. (+)-Bufuralol was devoid to beta-adrenoceptive blocking activity. Only tolamolol reduced the pressor response to i.v. phenylephrine in the conscious cat, indicating that alpha-adrenoceptive blocking activity may contribute to its hypotensive action. The results suggest that beta-adrenoceptive blocking activity is necessary for the hypotensive responses of these drugs. However, for the different drugs, there was no correlation between peripheral beta-adrenoceptive blocking activity and hypotensive response.

Adrenergic alpha-Antagonists↗
PubMed1989

The cardiovascular effects of centrally administered taurine in anaesthetised and conscious rats.

The effects of pentobarbitone anaesthesia on the cardiovascular changes induced by centrally administered taurine have been investigated in spontaneously hypertensive (SHR) and normotensive rats. Administration of taurine (100-400 micrograms) into the lateral cerebral ventricle (i.c.v.) of anaesthetised SHR and normotensive rats induced a dose-related fall in systemic blood pressure and heart rate, which tended to be of a greater magnitude in the SHR. In anaesthetised rats attached to a ventilator, taurine was not as potent at inducing a fall in systemic blood pressure, approximately double the dose being required to produce the same cardiovascular changes as that which occurred in anaesthetised rats without a ventilator. In conscious normotensive rats taurine had no effect on blood pressure until a dose of 800 micrograms was administered i.c.v., whereas in conscious SHR, a small, but significant depressor response was evident with 400 micrograms. These findings demonstrate that pentobarbitone anaesthesia sensitises the rats to the cardiovascular effects of taurine, partially through a mechanism which involves respiratory depression. Conversely in conscious rats a much higher dose of taurine is required to induce a fall in arterial pressure and heart rate per se.

Anesthesia↗
PubMed1989

Mechanisms of phenylalanine-induced pressor effects in conscious rats.

Phenylalanine and tyrosine reportedly decrease blood pressure in conscious restrained rats. However, tyrosine has recently been found to increase blood pressure in anesthetized animals, questioning the generality of findings obtained in restrained animals. The present study therefore evaluated the effects of phenylalanine on mean arterial pressure (MAP) and heart rate (HR) in unrestrained, conscious rats. Phenylalanine (0.32-1.33 mmol/kg i.p.) increased MAP and decreased HR, effects that were antagonized by carbidopa and prazosin but not by desipramine. In addition, both DOPA and tyrosine (1.33 mmol/kg) increased MAP. In contrast, phenylalanine-induced increases in plasma concentrations of its indirectly acting sympathomimetic amine metabolite, phenethylamine, were small and temporally unrelated to the phenylalanine-induced MAP elevation, and desipramine inhibited MAP increases produced by exogenous phenethylamine. These observations indicate that phenylalanine increases MAP in conscious, unrestrained animals by augmenting peripheral catecholamine synthesis and release rather than by affecting phenethylamine bioavailability.

Animals↗
PubMed1991

Effects of beta-adrenoceptor antagonism upon delayed reperfusion arrhythmias in conscious dogs.

Whereas isolated heart preparations or anesthetized animals have been used to assess the actions of beta-adrenoceptor antagonists upon reperfusion-induced arrhythmias, this study evaluated the possible antiarrhythmic effects of beta-adrenoceptor antagonism in conscious animals. Conscious, chronically instrumented dogs were subjected to a temporary occlusion of the left anterior descending coronary artery for 4 h. After the first hour of reperfusion, flestolol (N-(1,1-dimethyl-2- ureidoethyl)-2-hydroxy-3-(O-fluorobenzoyloxy)-propylamine sulfate), an ultra short-acting beta-adrenoceptor antagonist, was administered i.v. at infusion rates of 1 and 2.6 micrograms/kg per min. A control group received the equivalent volume of saline during this period. Delayed reperfusion-induced arrhythmias were evaluated by using a computerized analysis system. Treatment with flestolol did not affect the total number of beats, the number of normal and ectopic beats, and the arrhythmic ratio, i.e. the ratio of ectopic beats to the total number of beats. Hence, beta-adrenoceptor antagonism does not appear to suppress delayed ectopic activity during coronary reperfusion in conscious dogs.

Adrenergic beta-Antagonists↗
PubMed1993

Role of gastrin and cholecystokinin receptors in regulation of peptone-stimulated gastric acid secretion in conscious rats.

With the availability of selective gastrin/CCKB (L365,260) and CCKA (L364,718) receptor antagonists the present study was designed to investigate the role of gastrin and cholecystokinin (CCK) receptors in meal-stimulated gastric acid secretion. Gastric acid output was measured by continuous intragastric titration in conscious rats. Vehicle (dimethylsulfoxide/saline, 3:1), L365,260 (3 or 9 mg/kg), or L364,718 (1 mg/kg) was given by i.v. bolus injection. Basal acid output was strongly inhibited by both doses of L365,260 while L364,718 had no effect. Intragastric peptone (4%, w/v) increased acid secretion 40-65% of the response to a maximal dose (2.5 nmol/kg per h) of gastrin-17. L365,260 completely abolished gastrin-17 stimulated acid secretion and partially inhibited peptone-induced acid secretion. Blockade of CCKA receptors by L364,718 did not affect peptone-stimulated acid output. This study demonstrates that gastrin/CCKB receptors are important in regulating basal acid secretion in the conscious rat while CCKA receptors do not appear to influence basal or peptone-stimulated gastric acid secretion. Blockade of gastrin/CCKB receptors partially inhibits intragastric meal-stimulated acid secretion indicating that the gastrin/CCKB receptor has a physiological role as mediator of food-stimulated acid secretory response in conscious rats.

Animals↗
PubMed1995

SR 33589, a new amiodarone-like antiarrhythmic agent: anti-adrenoceptor activity in anaesthetized and conscious dogs.

We have assessed the ability of amiodarone and the new amiodarone-like antiarrhythmic agent, SR 33589 (N,N-dibutyl-3-[4-((2-butyl-5-methylsulphonamido)benzofuran-3-yl-c arbonyl) phenoxy]propylamine), to inhibit the effects of adrenoceptor stimulation in anaesthetized and conscious dogs. In anaesthetized, atropinized dogs, adrenoceptor stimulation was achieved (i) by i.v. administration of adrenaline and measurement of increased blood pressure (ii) by i.v. administration of isoprenaline and measurement of increased heart rate and decreased blood pressure. In conscious dogs, adrenoceptor stimulation was achieved by i.v. administration of isoprenaline and measurement of increased heart rate. In anaesthetized, atropinized dogs, both amiodarone and SR 33589 inhibited to similar extents, alpha-adrenoceptor stimulation (as indicated by attenuation of adrenaline-induced increases in blood pressure). The beta 1-adrenoceptor inhibitory activity of SR 33589 (as demonstrated by blockade of isoprenaline-induced increases in heart rate) was significant, but less marked than amiodarone (heart rate elevation reduced by 39%, P < 0.001 with 10 mg/kg SR 33589 and by 52%, P < 0.01 with 10 mg/kg amiodarone). In contrast, its beta 2-adrenoceptor antagonistic activity (as demonstrated by blockade of isoprenaline-induced reduction in blood pressure) was more marked (mean blood pressure decrease reduced by 69%, P < 0.01 with 10 mg/kg SR 33589 and by 31%, P < 0.05 with 10 mg/kg amiodarone). In conscious dogs, both SR 33589 and amiodarone (12.5, 25 and 50 mg/kg p.o.) inhibited isoprenaline-induced increases in heart rate by approximately the same amount for varying durations depending on the dose.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1987

Measurement of conscious symptom exaggeration by questionnaire: a clinical study.

This study compared measures of conscious exaggeration of symptoms by 157 patients with chronic pain who were involved in personal injury litigation with 106 patients not seeking compensation who were also attending a multidisciplinary pain clinic. Pain severity was assessed using a visual analogue scale and the adjectival check-list of the McGill Pain Questionnaire. There was no difference between the two groups on scores obtained on the Conscious Exaggeration (CE) scale; it was found that there was a significant correlation between CE scores and trait anxiety, hostility, state anxiety, and pain descriptors in the 'Miscellaneous' category of the McGill Pain Questionnaire. It was concluded that there is no support for the claim that the Conscious Exaggeration scale can detect deception with the object of financial gain among chronic pain patients involved in litigation.

Adolescent↗
PubMed1987

Simultaneous elevation of plasma insulin and catecholamines during endotoxicosis in the conscious and anesthetized rat.

Plasma levels of glucose, insulin and catecholamines were assessed during the early phase of sub-lethal endotoxicosis in fasted male rats which were either conscious or continuously anesthetized with sodium pentobarbital. Exogenous glucose challenge was administered during endotoxicosis to probe insulin release at a time when plasma catecholamines were elevated. An endogenous hyperglycemia occurred following endotoxin but was moderated by continuous pentobarbital anesthesia. Plasma insulin was elevated in the conscious but not anesthetized rats during endogenous hyperglycemia following endotoxin. Hyperglycemia with exogenous glucose elevated plasma insulin levels in both conscious and anesthetized groups and occurred in the presence of elevated levels of norepinephrine, epinephrine and dopamine. Simultaneous elevation of plasma catecholamine and insulin levels during endotoxicosis suggests that glucose utilization may be promoted at the same time that glucose is mobilized through adrenergic mechanisms. These events may contribute to the rapid depletion of carbohydrate stores leading to the hypoglycemia of the agonal stage of endotoxic shock.

Animals↗
PubMed1991

Intranasal activity of the growth hormone releasing peptide His-D-Trp-Ala-Trp-D-Phe-Lys-NH2 in conscious dogs.

This series of experiments was conducted to evaluate the growth hormone (GH) releasing activity of intranasally administered His-D-Trp-Ala-Trp-D-Phe-Lys-NH2 (GHRP-6, SK&F 110679) in conscious dogs. Intranasal administration of GHRP-6 increased plasma growth hormone levels in the conscious dog in a dose-related manner. Doses of 0.25 and 0.5 mg/kg produced GH levels of 11.3 +/- 4.8 ng/ml and 28.6 +/- 8.0 ng/ml, respectively. Peak levels were observed 15 minutes after dosing and GH levels were elevated for up to 105 minutes after intranasal dosing. Intranasal administration of isotonic saline did not produce any change in basal (negligable) GH levels. When GHRP-6 was given by the intravenous route, a maximal dose of 0.5 mg/kg, produced a peak plasma GH concentration of 60.8 +/- 10.5 ng/ml. Saline had no effect on GH levels when given intravenously. Using the intravenous and intranasal GH response data (i.e., area under the time-response curves), the intranasal bioavailability of GHRP-6 was estimated to be 34.4 to 44.9%. The results of these studies suggest that significant activity and excellent bioavailability can be achieved when GHRP-6 is administered by the intranasal route to conscious dogs. Based on these results, the intranasal activity of GHRP-6 should be evaluated in man. The successful intranasal administration of this peptide in man should provide GH therapy with reduced patient discomfort and better patient compliance when compared to presently available parenterally administered remedies.

Administration, Intranasal↗
PubMed1979

Caval occlusion technique for hepatic venous sampling: a new approach to estimating splanchnic substrate balance in conscious dogs.

We have proposed a new technique for sampling hepatic venous blood in conscious dogs. Sub-hepatic vena caval blood flow was temporarily occluded by a previously implanted inflatable snare so that all blood entering the inferior vena cava was hepatic venous effluent. Hepatic venous blood samples were collected from the inferior vena cava 8 seconds after beginning caval occlusion, with the total interval of flow occlusion lasting 12 to 15 seconds. No behavioral or metabolic alterations were observed when or metabolic alterations were observed when hepatic venous effluent was repetitively sampled using the caval occlusion technique. Net splanchnic glucose balance (NSGB) was measured in conscious dogs receiving saline, glucose or glucagon infusions. NSGB measurements made with the caval occlusion technique were in accord with previous results obtained via tracer methodology or arterio-venous difference techniques utilizing hepatic vein catheterization. The caval occlusion technique thus provides a method for collecting hepatic venous blood samples from conscious animals without the difficulties associated with hepatic vein catheterization.

Abdomen↗