Heart rate increase ketamine

Physical effects of high doses of ketamine include decreased respiration and heart rate, increased blood pressure, and the possibility of vomiting and convulsions. These can lead to cardiac and respiratory arrest, coma, and death. The risk of ketamine overdose is much greater when it is mixed with other drugs such as alcohol, Ecstasy, caffeine, or cocaine. Overdoses of ketamine have been reported when people boost the drug (take another dose before the first dose wears off) to prolong its psychedelic effects. 

As an anesthetic, ketamine increases sympathetic nervous activity, which results in an increased heart rate, increased blood pressure, some dilation of bronchial tubes, pupil dilation, and related secondary effects. 

At low doses, ketamine may result in impairment of attention, learning ability, and memory, and at high doses it has been associated with delirium, amnesia, impaired motor function, hypertension, depression, and respiratory depression (Krystal et al. 1994). Another mechanism of action appears to be a blocking of the reuptake of catecholamines. This effect leads to an increase in heart rate and blood pressure (Reich and Silvay 1989). 

Ketamine also can be contrasted to other intravenous drugs in its ability to cause cardiovascular stimulation rather than depression. The observed increases in heart rate and blood pressure appear to be mediated through stimulation of the sympathetic nervous system. In a healthy, normovolemic, unpremedicated patient, the initial induction dose of ketamine maintains or stimulates cardiovascular function. In contrast, patients with... 

The drug increases the heart rate, cardiac output and blood pressure which is due to sympathetic stimulation. Respiration is not depressed, muscle tone increases and reflexes are not abolished during anaesthesia. Ketamine has been recommended for short operations, unpleasant therapeutic and diagnostic procedures in children, operation in shocked patients and in obstetrics. 

Although ketamine produces direct myocardial depression, it has significant indirect cardiovascular effects through sympathomimetic effects and stimulation of the vasomotor centre. The heart rate and systolic blood pressure increase by 30% and occasionally up to 100%. Owing to the increased cardiac work and myocardial consumption, ketamine adversely affects the balance between myocardial oxygen supply and demand. Consequently, it is not recommended for use as the sole agent in adults with severe cardiovascular disease. However, the same haemodynamic effects, particularly the raised systemic vascular resistance, make the agent particularly suitable for children with cyanotic heart disease. 

Ketamine is the only intravenous anesthetic that possesses both anesthetic and analgesic properties, as well as the ability to produce dose-related cardiovascular stimulation. Heart rate, arterial blood pressure, and cardiac output can be significantly increased above baseline values. These variables reach a peak 2-4 minutes after an intravenous bolus... 

In very large quantities, DXM can cause effects similar to those of ketamine and PCP because these drugs affect similar sites in the brain. These effects can include impaired motor function, numbness, nausea/vomiting, and increased heart rate and blood pressure. On rare occasions, hypoxic brain damage—caused by severe respiratory depression and a lack of oxygen to the brain—has occurred due to the combination of DXM with decongestants often found in the medication. 

Ketamine is generally administered to patients intravenously, but it is also effective when administered by intramuscular, oral, and rectal routes. The onset of action is generally short (10 to 15 minutes) but the duration of anesthesia of a single dose is long. Ketamine is the only intravenous anesthetic that produces an increase in heart rate and arterial blood pressure. It can also markedly increase cerebral blood flow, oxygen consumption, and intracranial pressure. 

In the horse, induction with thiopental usually results in a brief increase in heart rate and a decrease in cardiac output but no significant change in arterial blood pressure. Arterial blood pressure is typically lower after thiopental induction than in ketamine-based anesthetic techniques (Bennett et al 1998, Muir et al 2000). However, when horses are placed on inhalation anesthetics for maintenance of anesthesia, the hemodynamic effects of the induction agents is short lived and the hypotension and reduced cardiac output typical of inhalation anesthesia predominates (Bennett et al 1998, Wagner et al 1996). Respiratory depression is significant with an accompanying increase in Paco2 and decrease in pH. 

Known as special K, jet, green, and other names on the street, ketamine is sometimes injected, but can be evaporated to solid crystals, powdered, and smoked, snorted, or swallowed. Marijuana cigarettes are sometimes soaked in the ketamine solution, allowed to dry, and then smoked. Ketamine has become popular as a rave club drug. Side effects include signiflcant transient increases in blood pressure and heart rate, respiratory depression, airway obstruction, apnea, muscular hypertonia, psychomotor and psychotomimetic effects, and acute dystonic reactions. Following overdose, seizures, polyneuropathy, increased intracranial pressure, respiratory arrest, and cardiac arrest may occur. 

Some people claim that ketamine makes colors seem brighter and sounds more vivid. Even a small dose of ketamine can increase the heart rate to a dangerous level. 

Cardiovascular System Unlike other anesthetics, induction doses of ketamine typically increase blood pressure, heart rate, and cardiac output. The cardiovascular effects are indirect and are most... 

Ketamine is a cardiovascular stimulant, increasing heart rate and blood pressure. This results in part from central sympathetic stimulation and possibly from inhibition of norepinephrine reuptake at sympathetic nerve endings. Analgesia and amnesia occur, with preservation of muscle tone and minimal depression of respiration. The answer is (A). 

Ketamine produces a mild increase in heart rate and systolic and diastolic blood pressure, but has generally been reported not to affect the respiratory rate. Because of laryngeal hyperreactivity, premedication with atropine or scopolamine is recommended, especially because salivation is increased by ketamine. 

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