Emergency drugs
Daniel Cottle, Shondipon Laha, Peter Nightingale in Anaesthetics for Junior Doctors and Allied Professionals, 2018
Metaraminol acts mainly by α1 vasoconstriction, leading to an increased SVR and thus a rise in BP. There is an associated reflex bradycardia and transient reduction in CO.It also has indirect effects to increase BP and coronary blood flow, and mild but much less clinically relevant β effects.It is most useful for situations where there is vasodilatation (e.g. regional anaesthesia) or where tachycardia and hypotension exist (to be given in combination with a fluid challenge).Because of its indirect effects, a reaction with monoamine oxidase inhibitors (MAOIs) can cause a hypertensive crisis.
Neck Holds
Darrell L. Ross, Gary M. Vilke in Guidelines for Investigating Officer-Involved Shootings, Arrest-Related Deaths, and Deaths in Custody, 2018
While reflex bradycardia has been noted in a number of studies, there have been no reported deaths or bradycardic events to the point of requiring cardiac resuscitation in any of these studies (Arnold, 1999; Berk, Shea, & Crevey, 1991; Kornblum 1986a). Moreover, the medical literature is replete with studies looking at the use of carotid sinus massage as a diagnostic and therapeutic examination tool. In studies of thousands of uses on elderly patients, there were no complications of death or bradycardic events requiring treatment or resuscitation, even though this age group is traditionally more likely to have carotid sinus syndrome and more likely to be symptomatic from carotid sinus stimulation (Pollanen et al., 1998; Reay & Mathers, 1983). In fact, the diagnosis of carotid sinus syndrome, although well written about, is essentially unheard of in patients under the age of 50 years (Brignole & Menozzi, 1992; Coplan & Schweitzer, 1984; Kenny & Richardson, 2001; Mallet, 2003).
Clinical and Experimental Evaluation of Sympatho-Vagal Interaction: Power Spectral Analysis of Heart Rate and Arterial Pressure Variabilities
Irving H. Zucker, Joseph P. Gilmore in Reflex Control of the Circulation, 2020
Reflex bradycardia accompanying rises in arterial pressure has traditionally been considered the result of the stimulation of a restricted reflexogenic area (Heymans and Neil, 1958). More recently, it became appreciated (Sagawa, 1983) that multiple baroreceptors send neural signals to various levels of the central nervous system and through multiple-efferent pathways to a variety of effector organs. However, such a multiinput-multioutput and multilevel regulatory mechanism has never been interpreted to depend also on the interplay of reflexes of opposite signs.
Descriptions and outcomes of cardiac evaluations in pediatric patients hospitalized for asthma
Published in Journal of Asthma, 2020
Raymond Parlar-Chun, Kokila Kakarala, Mani Singh
There is limited epidemiological data on respiratory causes of syncope compared to cardiac syncope or vasovagal syncope. Katz reported on a series of cases in asthmatic children where asthma and persistent cough caused transient syncopal episodes. These patients typically returned to baseline within ten seconds with a negative pathological workup and no EEG or EKG abnormalities. Asthma was the source of cough in these patients and syncope was thought to be the result of transient cerebral hypoxia resulting from cough induced increases in intrapleural pressure, decreased venous return, decreased right ventricle output, decreased left ventricle filling, and decreased cardiac output (16). There have also been reported cases of inhaler syncope caused by reflex bradycardia and asystole produced by the use of asthma inhalers (17). In our 6 syncopal patients, one episode was result of cardiac syncope with a new diagnosis of hypertrophic cardiomyopathy. The other five could be plausibly explained by vasovagal, cough, or inhaler syncope causes.
Cardiovascular and metabolic consequences of the association between chronic stress and high-fat diet in rats
Published in Stress, 2018
Bruna B. Simas, Everson A. Nunes, Carlos C. Crestani, Guilherme F. Speretta
Paired values of MAP and HR changes evoked by phenylephrine and SNP infusion were plotted to generate sigmoid logistic functions (Crestani et al., 2010; Head & McCarty, 1987; Korner, Shaw, West, & Oliver, 1972). Baroreflex analysis using sigmoid curves was characterized by five parameters: (a) lower HR plateau (P1; in beats/min; i.e. maximum reflex bradycardia); (b) upper HR plateau (P2; in beats/min; i.e. maximum reflex tachycardia); (c) HR range (in beats/min; i.e. difference between upper and lower plateau levels); (d) median blood pressure (BP50; in mm Hg), which is the MAP at 50% of the HR range; and (e) average gain (G; in beats/min per mm Hg), which is the average slope of the curves between +1 and −1 standard derivations from BP50 (Crestani et al., 2010; Head & McCarty, 1987).
A randomized open label, parallel-group study to evaluate the hemodynamic effects of Cafedrine/Theodrenaline vs Noradrenaline in the treatment of intraoperative hypotension after induction of general anesthesia: the “HERO” study design and rationale
Published in Current Medical Research and Opinion, 2023
Benjamin Vojnar, Götz Geldner, Susanne Huljic-Lankinen, Melanie Murst, Thomas Keller, Stephan Weber, Christine Gaik, Tilo Koch, Andreas Weyland, Peter Kranke, Sascha Kreuer, Daniel Chappell, Leopold Eberhart
While both medicinal products effectively increase blood pressure, pharmacologic properties suggest a more pronounced increase of cardiac output in response to C/T when compared to NA. Cafedrine/Theodrenaline has been shown to effectively increase the MAP by combined effects on preload, contractility, and afterload, while heart rate is mostly unaffected14. Increase of cardiac index (CI) and MAP seem to be more pronounced in women15. Noradrenaline has potent alpha-adrenergic and slight beta-adrenergic effects resulting in potent vasoconstriction and less potent inotropy. The increase in blood pressure may cause reflex bradycardia16,17. To date, no direct comparison between the two medicinal products is available.