Succinylcholine, a short-acting depolarizing agent

(0.5 to 1.0 mg/kg), is used in most patients. Before the muscle relaxant is administered, a blood pressure cuff is inflated above the systolic blood pressure at one ankle, to allow observation of the motor seizure. A peripherally acting anticholinergic such as glycopyrrolate may used to increase heart rate before treatment, especially if the #Epacadostat price keyword# patient is bradycardic. ECT is administered using two electrodes, located bilaterally or unilaterally, as illustrated in Figure 1. The electrical stimulus is a brief pulse waveform (bidirectional rectangular pulse). The intensity of the ECT stimulus Inhibitors,research,lifescience,medical is assessed in terms of the total delivered charge. This total charge (Q, measured using units of millicoulombs) can be defined as: Figure 1. Electrode placement in ECT. In bilateral ECT, bifrontotemporal electrode placement is used: the electrodes are placed 5 cm above the midpoint of the distance between the auditory meatus and the external canthus. In unilateral ECT, the d’Elia positioning … Q = (1/1000) * PW * 2F * D where I is current (milliamperes), PW is pulse width (milliseconds),

F is frequency (hertz, cycle per second) and D is duration (seconds). The standard pulse width used in ECT is 1 millisecond or greater. Recently, it has been found that an ultrabrief stimulus, using 0.3 Inhibitors,research,lifescience,medical Inhibitors,research,lifescience,medical millisecond pulse width, requires less energy to produce a generalized seizure. This may be related to the fact that neuronal depolarization is 0.3 to 1.0 milliseconds, and long pulse width may result in excess stimulation after neurons have fired and are in a refractory or relative refractory phase. Although the amnesia and Inhibitors,research,lifescience,medical cognitive side effects following ECT are reduced with ultrabrief stimulation, data regarding its efficacy relative to the traditional stimulus are still insufficient. The electrical path of the ECT stimulus includes the ECT output device, stimulus electrodes, scalp,

skull, cerebrospinal fluid, and brain tissue. The most variable impediment is the patient impedance (mostly scalp and skull), measured in ohms. Energy is another unit that assesses the intensity of the total electrical stimulus. It is dependent on the impedance first during stimulation, and can be calculated as U = (Q/1000) * (1/1000) * R where Q is charge (millicoulombs), I is current (milliamperes), and R is resistance (ohms). Seizure threshold, defined as the minimal stimulus intensity necessary to produce a seizure, differs up to 40-fold among patients (Figure 2). For example, seizure threshold is higher in men than in women and is higher in older than younger adults. Seizure threshold is also altered by mechanical factors that impede the path of the stimulus and increase resistance.