Ketamine hypertension with

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). 

In overdose, ketamine may lead to hyperthermia, seizures, hypertensive crisis, coma, and even death. These symptoms are generally thought to be caused by ketamine s catecholaminergic effects (Reich and Silvay 1989). Ketamine is physically addicting, with a described withdrawal syndrome. 

Other reported side effects include vomiting, salivation, lacrimation, shivering, skin rash, and an interaction with thyroid preparations that may lead to hypertension and tachycardia. Ketamine also may raise intracranial pressure and elevate pulmonary vascular resistance, especially in children with trauma or congenital heart disease. Increases in intraocular pressure also may occur, and vigilance is required if ketamine is used in ocular surgery. 

If a (3-adrenoceptor antagonist is administered prior to sufficient ol-radrenoceptor blockade, a hypertensive episode may be precipitated with cardiac failure and pulmonary oedema. Most intravenous anaesthetic agents have been used safely, but ketamine is contraindicated. Sodium nitroprusside can be used to achieve arteriolar dilation. Esmolol, a pi-selective antagonist with very short duration of action, is administered intravenously to prevent cardiac arrhythmias intra-operatively. After tumour removal, volume administration should be aggressive to maintain haemodynamic stability, and a noradrenaline infusion may be required. 

PCP and ketamine produce detachment, disorientation, distortions of body image, and loss of proprioception. Somatic symptoms and signs include numbness, nystagmus, sweating, rapid heart rate, and hypertension. Overdosage has been fatal, as contrasted with the absence of known human fatalities directly caused by drugs of the LSD group. 

THYROID HORMONES ANAESTHETICS -GENERAL-KETAMINE Cases of tachycardia and hypertension when ketamine was given to patients on thyroxine this required treatment with propanolol Uncertain Monitor PR and BP closely... 

Tachycardia and hypertension are common after anesthetic induction with ketamine, although the hypertension can be limited by the addition of diazepam (10). Nodal dysrhythmias can also occur (11). Because of possible... 

Fontana M, Mastrostefano R, Pietrangeli A, Madonna V. Acute intracranial hypertension syndrome due to ketamine in a patient with delayed radionecrosis simulating an expansive process. J Neurosurg Sci 1980 24(2) 93-8. 

Two patients taking levothyroxine developed severe hypertension (240/140 and 210/130 mmHg, respectively) and tachycardia (190 and 150 bpm) when they were given ketamine. Both were eflectively treated with 1 mg of intravenous propranolol. It was not clear whether this was an interaction or simply a particularly exaggerated response to ketamine, but care is clearly needed if ketamine is given to patients taking thyroid replacement. 

The effect of ketamine on intracranial pressure remains controversial, but the drug should certainly be avoided in patients with refractory intracranial hypertension. Ketamine may cause nystagmus, diplopia, and lacrimation. It may transiently increase intraocular pressure. 

A further study reviewed 18 patients over a 3 year period with acute agitation and psychiatric illness requiring aero medical retrieval imder the mental health act [5(T]. Intravenous ketamine for sedation of patients was used as an alternative to a general anaesthetic and intubation. Patients were given up to two bolus doses of 0.5-1 mg/kg followed by an infusion of 1-1.5 mg/kg/hr. Only mild adverse events occurred with four patients having hypertension and tachycardia all of which spontaneously resolved. One patient vomited but there were no incidences of aspiration and no airway intervention was required. Thus ketamine could be considered as a safe alternative to general anaesthetic in this study population. 

The major side effects of this drug (psychomimetic symptoms during recovery, hypertension and elevation of intracranial pressure) are described in SED VIII. Little new information has been published since, but the addition of sedative drugs has been found to reduce the incidence of the psycho-mimetic symptoms, as was shown in a double-blind trial where ketamine was used with or without flunitrazepam (56C). 

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