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Anesthesia for Thyroid Surgery
Published in Madan Laxman Kapre, Thyroid Surgery, 2020
Vidula Kapre, Shubhada Deshmukh, Pratibha Deshmukh, Meghna Sarode, Rajashree Chaudhary
In hyperthyroid patients there are chances of arrythmias, which are further compounded by sympathetic responses to laryngoscopy and intubation and use of volatile anesthetic agents. To avoid this, the plane of anesthesia should be deep, with good analgesia, and use of volatile anesthetic agents with less arrhythmogenicity like Sevoflourane and Desflurane. Dexmedetomidine is a useful drug which can be used intra-operatively. It has the benefit of maintaining heart rate, blood pressure, and provides analgesia. It also reduces post-operative nausea and vomiting [5–7].
Neuropharmacology: Age-related changes
Published in Hemanshu Prabhakar, Charu Mahajan, Indu Kapoor, Essentials of Geriatric Neuroanesthesia, 2019
Katleen Wyatt Chester, Olivia Johnson Morgan, Kruti Shah
Dexmedetomidine quickly produces light sedation by its action in the pontine locus coeruleus where it selectively activates central-alpha-2 receptors, thereby producing sedative effects quickly. Unlike other sedatives, dexmedetomidine does not impair the respiratory drive. Hemodynamically, this medication causes dose-dependent decreases in heart rate and blood pressure that are most pronounced with bolus doses. Although dexmedetomidine has mild analgesic effects and has been shown to be an opioid-sparing agent, it should not be used as monotherapy for analgesia. Since the actions of dexmedetomidine are limited to the locus coeruleus, a noradrenergic nucleus near the 4th ventricle, it has no effects on electrophysiologic tests. Lacking electrophysiologic and respiratory effects, dexmedetomidine has gained much interest in functional neurosurgery and awake procedures (48). In addition, interest is growing for the use of dexmedetomidine as an adjuvant agent during particularly noxious parts of neurosurgical cases rather than increasing doses of the standard anesthetics in response to the patient's increasing heart rate and blood pressure.
Delirium
Published in Ad (Sandy) Macleod, Ian Maddocks, The Psychiatry of Palliative Medicine, 2018
Ad (Sandy) Macleod, Ian Maddocks
Deep sedation with respiratory support may rarely be required to control severe hyperactive deliria. Propofol at low dosage (10–50 μg/kg/min) has been used to anaesthetise these patients to enable treatment of the life threatening cause (such as acute viral encephalitis). Dexmedetomidine, a selective alpha2- adrenergic receptor agonist, a novel anaesthetic agent, has also been trialled in postoperative delirium.63 Dexmedetomidine has the potential to allow a state of tranquillity and analgesia, without sedation.
Sublingual dexmedetomidine: repurposing an anesthetic as an anti-agitation agent
Published in Expert Review of Neurotherapeutics, 2023
Justin Faden, Meghan Musselman, Leslie Citrome
Dexmedetomidine is highly protein-bound, with 94% bound to albumin and alpha-1-glycoprotein. Dexmedetomidine has been shown to distribute widely throughout the body and crosses the blood-brain and placental barriers[30]. The fraction of the drug bound to protein in individuals with hepatic impairment was decreased compared to healthy subjects, and hepatic impairment impacts the mean elimination half-life of the drug [26,30]. Both prolonged and shortened elimination half-lives have been reported in patients with hypoalbuminemia, though clearance is largely unaffected[30]. Dexmedetomidine pharmacokinetics are not significantly different in patients with creatinine clearance <30 mL/minute as compared to those patients with normal renal functioning[26]. Studies of the intravenous formulation of dexmedetomidine have evaluated the impact of physical factors on drug pharmacokinetics. Reduced cardiac output has demonstrated an impact on clearance of the drug. Racial differences in pharmacokinetics of the drug have not been demonstrated. Age and height are also unlikely to impact pharmacokinetics, though body weight is expected to impact the steady state and peak concentration of the drug in an inverse fashion[30].
Effects of perioperative dexmedetomidine infusion on renal function and microcirculation in kidney transplant recipients: a randomised controlled trial
Published in Annals of Medicine, 2022
Yin-Chin Wang, Ming-Jiuh Wang, Chih-Yuan Lee, Chien-Chia Chen, Ching-Tang Chiu, Anne Chao, Wing-Sum Chan, Meng-Kun Tsai, Yu-Chang Yeh
Dexmedetomidine is a highly selective alpha-2 agonist with sedative and analgesic effects [5]. It modulates inflammation by enhancing parasympathetic tone while reducing sympathetic tone [6,7]. Dexmedetomidine has been reported to confer renal protection effects in patients undergoing coronary artery bypass surgery [8,9]. The protective effects of dexmedetomidine against ischemia-reperfusion injury have been described in many studies [10–12]. Moreover, the sympatholysis effect of dexmedetomidine induced vasodilation [5], and our previous animal study showed that dexmedetomidine prevented alterations of intestinal microcirculation in rats with surgical stress and pain [13]. However, the most common side effects of dexmedetomidine are bradycardia and hypotension. Low cardiac output and low perfusion pressure may deteriorate microcirculation [14,15]. We hypothesised that dexmedetomidine could attenuate the ischemia-reperfusion injuries and preserve transplanted kidneys’ function. In addition, the issue that the effects of dexmedetomidine on perioperative microcirculation were protective or detrimental remained unknown. Thus, this study investigated postoperative renal function and perioperative sublingual microcirculation in patients undergoing kidney transplantation.
Multimodal analgesia in neurosurgery: a narrative review
Published in Postgraduate Medicine, 2022
Caterina Aurilio, Maria Caterina Pace, Pasquale Sansone, Luca Gregorio Giaccari, Francesco Coppolino, Vincenzo Pota, Manlio Barbarisi
Dexmedetomidine is a new α2 -receptor agonists that has the property as anesthetic sparing that allow a reduction in the amount of inhaled anesthetics and opioids needs, resulting in a more rapid recovery with fewer side effects. In the central nervous system (CNS), dexmedetomidine acts through the release of catecholamines in nerve endings and by reducing the sympathetic nervous system activation [24]. It was also found that the direct action on α2 receptors in monoaminergic neurons and dendrites in the brain inhibits the secretion of catecholamines [25]. Both these studies concluded that dexmedetomidine could reduce neuronal damage by inhibiting neurotransmitter release, which may improve ischemic perfusion and metabolic disorders [26]. Furthermore, these researches brought the interest in the use of dexmedetomidine as analgesic in the postoperative craniotomy surgery and as part of multimodal analgesia. The interest for dexmedetomidine in intracranial and postoperative surgery is based not only on analgesia and a cooperative sedation but also on a better hemodynamic stability, on reducing respiratory depression, intracranial pressure, and the risk of post-operative bleeding for its sympatholytic mechanisms. In two studies including 128 patients, dexmedetomidine was used in the similar way with an infusion of up to 0.5µgr/kg/hr or placebo intraoperatively to evaluate post-craniotomy pain. Dexmedetomidine lead to a reduction in pain score up to 24 h postoperatively with a less 27,28].