Effects of cardiac output on the onset of rocuronium-induced neuromuscular block in elderly patients

Abstract

Purpose

The aim of this study was to elucidate the relationship between the onset of rocuronium-induced neuromuscular block and arterial pressure-based cardiac output (CO) in elderly patients.

Methods

Forty elderly patients aged 65–83 years were enrolled in this study. After induction of anesthesia, contractions of the adductor pollicis muscle to ulnar nerve train-of-four stimulation were acceleromyographically evaluated and 1 mg/kg rocuronium was administered following CO measurement. The correlation between onset of rocuronium action and CO was analyzed.

Results

The mean [SD] CO reduced after induction of anesthesia from 5.1 [1.8] L/min to 3.8 [1.1] L/min. The onset time of rocuronium-induced neuromuscular block was 110.3 [23.9] s (range 60–165). There was a statistically significant inverse correlation between the onset time of rocuronium and CO [onset time (s) = − 13.2·CO + 159.7, R² = 0.376].

Conclusions

In the elderly, CO influences the onset of action of rocuronium.

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Endothelium-dependent vasodilation in the cerebral arterioles of rats deteriorates during acute hyperglycemia and then is restored by reducing the glucose level

Abstract

Purpose

Acute hyperglycemia in patients with traumatic brain injury correlates with a poor neurological outcome. We investigated the endothelium function of rat cerebral arterioles during acute hyperglycemia and after reducing the glucose levels using insulin. We also examined whether or not oxidative stress was involved in the cerebral arteriole response to acute hyperglycemia.

Methods

In isoflurane-anesthetized, mechanically ventilated rats, we used closed cranial window preparation to measure the changes in the pial arteriolar diameter following the topical application of acetylcholine (ACh) or adenosine. We examined the pial arteriolar vasodilator response before hyperglycemia, during hyperglycemia, and after reducing the glucose level using insulin. After intravenous pretreatment with an NADPH oxidase inhibitor (apocynin or diphenylene iodonium), we reexamined the pial arteriolar vasodilator response following the topical application of ACh.

Results

Under control conditions, the topical application of ACh dose-dependently dilated the cerebral arterioles. The vasodilatory responses to topical ACh were impaired during hyperglycemia and improved after the administration of insulin. The vasodilatory responses to topical adenosine were not affected by the glucose levels. In the apocynin or diphenylene iodonium pretreatment group, the topical application of ACh dilated the cerebral arterioles during hyperglycemia.

Conclusion

Acute hyperglycemia induces a dysfunction of the endothelium-dependent vasodilation of rat cerebral arterioles. The dysfunction can be reversed by improving the acute hyperglycemia and it can be prevented entirely by the administration of NADPH oxidase inhibitors. These results could suggest that controlling the glucose levels works protectivity to endothelium function of cerebral arterioles.

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Head Immobilization in Experiments on Awake Animals: Minimization of Stress

An original head holder and a training procedure designed for better adaptation of animals to rigid immobilization carried out in experiments in the awake drug-free state without body and limb restraining are described. The head holder can be used autonomously or in combination with a standard stereotaxic apparatus; it provides possibilities for stable recording of brain neuronal activity and delivery of pharmacological drugs. The device may be successfully used in both electrophysiological and behavioral experiments, particularly in studies of sensory perception and eye-head coordination. The proposed head holder and flexible training program provide much weaker immobilization-induced stress-related effects, which preserves normal physiological functions of the animal. The device may be successfully used for different laboratory animal species.

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Junior temperament character inventory together with quantitative EEG discriminate children with attention deficit hyperactivity disorder combined subtype from children with attention deficit hyperactivity disorder combined subtype plus oppositional defiant disorder

Publication date: Available online 19 May 2018
Source:International Journal of Psychophysiology
Author(s): Giuseppe A. Chiarenza, Stefania Villa, Lidice Galan, Pedro Valdes-Sosa, Jorge Bosch-Bayard
Oppositional defiant disorder (ODD) is frequently associated with Attention Deficit Hyperactivity Disorder (ADHD) but no clear neurophysiological evidence exists that distinguishes the two groups. Our aim was to identify biomarkers that distinguish children with Attention Deficit Hyperactivity Disorder combined subtype (ADHD_C) from children with ADHD_C + ODD, by combining the results of quantitative EEG (qEEG) and the Junior Temperament Character Inventory (JTCI).28 ADHD_C and 22 ADHD_C + ODD children who met the DSMV criteria participated in the study. JTCI and EEG were analyzed. Stability based Biomarkers identification methodology was applied to the JTCI and the qEEG separately and combined. The qEEG was tested at the scalp and the sources levels. The classification power of the selected biomarkers was tested with a robust ROC technique. The best discriminant power was obtained when TCI and qEEG were analyzed together. Novelty seeking, self-directedness and cooperativeness were selected as biomarkers together with F4 and Cz in Delta; Fz and F4 in Theta and F7 and F8 in Beta, with a robust AUC of 0.95 for the ROC. At sources level: the regions were the right lateral and medial orbito-frontal cortex, cingular region, angular gyrus, right inferior occipital gyrus, occipital pole and the left insula in Theta, Alpha and Beta. The robust estimate of the total AUC was 0.91. These structures are part of extensive networks of novelty seeking, self-directedness and cooperativeness systems that seem dysregulated in these children. These methods represent an original approach to associate differences of personality and behavior to specific neuronal systems and subsystems.



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Comprehensive Statistical Analysis of the Gait Parameters in Neurodegenerative Diseases

Neurodegenerative diseases significantly alter the gait dynamics and, hence, various gait parameters. In this paper, we present results of a comprehensive statistical analysis of the gait time parameters, namely swing interval, stance interval, stride interval, and double support interval, in healthy individuals and patients suffering from neurodegenerative diseases (Huntington's, HD, Parkinson's, PD, and amyotrophic lateral sclerosis, ALS). Multivariate analysis of variance (MANOVA) along with other tests, including univariate tests, post-hoc tests, and discriminant analysis, were employed in this study. Results of discriminant analysis demonstrated that the groups differed significantly from each other with respect to the dependent variables (P < 0.05). All the variables had a strong positive relationship with the first variate or factor, and the left swing, right swing, right stride, and left stride had a positive relationship with the second variate; the double support had a negative relationship. Results of our analyses provide a direction for the selection of certain gait parameters for automatic classification of neurodegenerative diseases based on these parameters.

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Anticipatory Inhibition of EMG Activity of the Human M. Soleus at Voluntary Contraction of Its Antagonists

Quantitative changes in background tonic EMG activity of m. soleus within a premotor period of voluntary contraction of its antagonists were examined in healthy humans. The above activity was recorded in the lying position at voluntary moderate tonic tension of this muscle and in the upright position, where the body was supported by both legs. The effect of voluntary flexion of the ipsilateral ankle joint (a simple motor reaction to a light signal) was examined. It was found that the intensity of soleus EMG in both tested positions, began to decrease 30–60 msec before the appearance of EMG activity recorded from the ankle flexor m. tibialis anterior, and such inhibition reached the maximum at the end of the premotor period. The observed dynamics of tonic EMG in the m. soleus show that an anticipatory drop in the activity of soleus motoneurons develops before the beginning of voluntary movements. Possible physiological mechanisms underlying this phenomenon are discussed. We believe that, within the premotor period, impulsation coming via mostly the corticospinal tract to soleus motoneurons decreases due to the action of central motor commands, and this leads to lowering of tonic tension of this muscle.

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Effects of Intrahippocampal Injections of Melipramin on EEG, Brain Self-Stimulation, and Behavioral Indices of Rats under Conditions of Neurogenic Stress

In young (3-month-old) male Wistar rats, we studied the effects of intrahippocampal microinjections of melipramin under conditions of emotional stress induced by sessions of electrical nociceptive stimulation of the limbs. In most cases, seven-day-long stressing resulted in suppression of electrical activity of the hippocampus, exerted ambivalent effects on the frequency of brain self-stimulation (BSS) events, decreased the communicability of animals in the two-chamber test, and increased the latencies of going of the animal from the arena center and grooming episodes in the open field test. Injections of melipramin interfered with the development of stress-induced disorders in the hippocampus, decreased the normalized content of beta oscillations in the neocortex and the theta-index in the hypothalamus, increased the BSS frequency, and decreased the level of negativation of the behavioral manifestations of this phenomenon. The duration of stay of a rat near the partition in the two-chamber test increased, the mobility and number of grooming episodes in the open field enhanced, but the latency of leaving the arena center also increased (similarly to what was observed in the control). On the 8th–9th day of the poststress period, behavioral disorders of rats of the control group in the two-chamber test were smoothed to a significant extent. The stability of the examined indices or the reverse development of stress-induced disorders within the above period in animals injected with melipramin were indicative of a significant role of the hippocampus in the formation of central effects of this antidepressant and also of adaptogenic and stress-protective properties of this drug.

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