Search results for "Anesthesia"

High pancuronium sensitivity of axonal nicotinic-acetylcholine receptors in humans during organophosphate intoxication.

1991

The effect of low-dose pancuronium on neuromuscular transmission was studied in 2 patients during the early and late stages of severe organophosphate intoxication. Single evoked compound muscle action potentials (CMAP) were followed by repetitive discharges and a decrement-increment (D-I) phenomenon with 10-, 20-, and 50-Hz supramaximal nerve stimulation. Intravenous pancuronium, 1 mg, abolished the D-I phenomenon, while the repetitive discharges of the CMAP were only partially reduced. It is postulated, that the disappearance of the D-I phenomenon with persistence of the CMAP repetitive discharges results from blockade of nicotinic-acetylcholine receptors located on the terminal axon respo…

Neuroimaging for the anesthesiologist.

2007

Neuroimaging is essential in the treatment of cerebral nervous system disorders or in patients in the ICU with deterioration of their neurologic function. Leading clinical symptoms are acute neurologic deficits with different stages of hemisymptomatology, primary or progressing loss of consciousness or vigilance deficit, focal or generalized seizures, sometimes combined with an acute respiratory or circulatory insufficiency. The resulting questions can be summarized in those of intracranial space occupying hemorrhage; acute infarction; and signs for reduced cerebral blood flow, cerebrovascular vasospasm, or intracranial mass. Recent evolutions in imaging have contributed to an increase in d…

Neurogenic Inflammation in Complex Regional Pain Syndrome (CRPS)

2008

This chapter explains symptoms and nature of neurogenic inflammation and its importance in posttraumatic complex regional pain syndrome (CRPS). Neurogenic inflammation regularly accompanies excitation of primary afferent nociceptors. It has two major components – plasma extravasation and vasodilatation. The most important mediators are the neuropeptides calcitonin gene-related peptide (CGRP) and substance P (SP). After peripheral trauma, immune reaction (e.g., cytokines) and the attempts of the tissue to regenerate (e.g., growth factors) sensitize nociceptors and thereby amplify neurogenic inflammation. This cascade of events has recently been demonstrated in rat models of CRPS employing di…

Electrophysiological evidence of memory-based detection of auditory regularity violations in anesthetized mice

2017

In humans, automatic change detection is reflected by an electrical brain response called mismatch negativity (MMN). Mismatch response is also elicited in mice, but it is unclear to what extent it is functionally similar to human MMN. We investigated this possible similarity by recording local field potentials from the auditory cortex of anesthetized mice. First, we tested whether the response to stimulus changes reflected the detection of regularity violations or adaptation to standard stimuli. Responses obtained from an oddball condition, where occasional changes in frequency were presented amongst of a standard sound, were compared to responses obtained from a control condition, where no…

Attention and distraction have no modulatory effect on the nociceptive withdrawal reflex

2007

General anaesthetics and the developing brain: an overview

2014

Various experimental studies in animals have shown that general anaesthetics are potentially toxic to the developing brain. By inducing apoptosis or interfering with neurogenesis, anaesthetic exposure during a critical period of neuronal development can have significant impact on neurocognitive function later in life. It remains controversial whether these experimental results can be transferred to human beings and this is under intensive scientific evaluation. To gain more insight into possible neurotoxic effects on the human brain of infants and small children, a number of retrospective studies have been performed. At present, there is no clear evidence that exposure to anaesthesia up to …

Acute Hemodynamic Effects of Nicorandil in Coronary Artery Disease

1992

Nicorandil is a potent vasodilator with antianginal and anti-ischemic properties that acts on both the coronary and the peripheral vascular bed. Because of its dual vasodilatory mechanisms mediated by an increase in cyclic GMP similar to that of nitrates and by a selective increase in the K+ conductance of the smooth muscle cell membrane, nicorandil unloads the right and left ventricles at rest and during exercise. Thus, compared with the classic nitrates, nicorandil is a more balanced vasodilator, i.e., it affects not only the venous capacitance vessels (as predominantly affected by nitrates) but also the arterial resistance vessels. In clinical pharmacologic trials, nicorandil has been ad…

Effects of Ca2+ entry blockers on CaCl2-, KCl- and noradrenaline-induced contractions of goat cerebral arteries

1990

Abstract The effects of three Ca 2+ entry blockers, nicardipine, nimodipine and verapamil, on CaCl 2 -, KCl- and noradrenaline-induced contractions were examined in isolated goat middle cerebral artery. The relationship between the effects of Ca 2+ entry blockers and the extracellular Ca 2+ dependence of the contractions was also examined. In ‘nominally’ Ca 2+ -free medium, addition of CaCl 2 induced concentration-dependent contractions of previously depolarized arteries. Withdrawal of Ca 2+ from the extracellular medium caused strong inhibition of the KCl- and noradrenaline-induced arterial contractions. Addition of EGTA to the Ca 2+ -free medium almost abolished the noradrenaline-response…

Relaxant effects of sodium nitroprusside and NONOates in goat middle cerebral artery: delayed impairment by global ischemia-reperfusion.

1999

Global cerebral ischemia and subsequent reperfusion induce early impairment of the vasodilator responses to hypercapnia and vasoactive substances. Nitric oxide (NO) is involved in the regulation of cerebral blood flow (CBF) in both health and disease. The present study was designed to assess possible changes in the cerebrovascular reactivity to NO donors induced by cerebral ischemia-reperfusion in goats. Female goats (n = 9) were subjected to 20 min global cerebral ischemia under halothane/N2O anesthesia. Sixteen additional goats were sham-operated as a control group. One week later the effects of ischemia-reperfusion on relaxations to NO donors sodium nitroprusside (SNP), diethylamine/NO (…

Deliberate Arterial Hypotension Does Not Reduce Intraocular Pressure in Pigs

1992

Among the accepted advantages of general anesthesia in ophthalmic surgery is improved control of intraocular pressure (IOP). Although standard textbooks advocate deliberate arterial hypotension to facilitate intraocular surgery by reducing IOP, scientific proof of such an effect is lacking. The authors investigated effects of induced arterial hypotension on IOP in an anesthetized porcine model. Forty-two piglets were anesthetized with piritramide, were placed in the prone position, and had the anterior chamber of one eye punctured with a small Teflon cannula to measure IOP. Six pigs were used in a pilot study to establish dose-response relationships for the hypotensive agents; 36 pigs were …