1/6. ketamine dependence.ketamine hydrochloride is a safe and rapid-acting non-opioid, lipid soluble anaesthetic with a short elimination half-life that is used for medical and veterinary purposes. It produces a state of "dissociative anaesthesia", probably from action on N-methyl-D-aspartate (NMDA) receptors. The psychotropic effects of ketamine range from dissociation and depersonalization to psychotic experiences and include a sensation of feeling light, body distortion, absence of time sense, novel experiences of cosmic oneness and out-of-body experiences. Abuse of ketamine has been reported, the typical abuser being an individual who uses multiple drugs and has some contact with medical agencies. This case demonstrates the effects of large doses of ketamine in a person with polysubstance abuse. The case also highlights development of significant tolerance to ketamine without prominent withdrawal symptoms. Caution in use of ketamine is reiterated in light of its abuse liability.- - - - - - - - - - ranking = 1keywords = anaesthesia (Clic here for more details about this article) |
2/6. Amphetamine ingestion presenting as eclampsia.A case of amphetamine abuse in late pregnancy is reported. The presenting features of convulsions, confusion, agitation with hypertension and proteinuria led to a diagnosis of eclampsia for which a caesarean section was performed. Investigations and differential diagnosis of convulsions in late pregnancy are reviewed. A general urinary drug screen gives results after 24 hr whereas, if amphetamine abuse is suspected, this can be confirmed within three hr if a specific test for urinary amphetamines is performed. The sympathomimetic effects of a single dose of amphetamine are contrasted with the depression of the sympathetic nervous system which occurs after long-term use. Implications for anaesthesia are discussed.- - - - - - - - - - ranking = 1keywords = anaesthesia (Clic here for more details about this article) |
3/6. Chronic cardiac toxicity after inhalation of 1,1,1-trichloroethane.Two patients showed evidence of chronic cardiac toxicity after repeated exposure to 1,1,1-trichloroethane. In both cases there was circumstantial evidence of a deterioration after routine anaesthetic use of the related compound halothane. An adolescent boy who sniffed trichloroethane presented with multiple ventricular arrhythmias during tonsillectomy. Follow up showed mild chronic left ventricular impairment. A 54 year old man had repeated industrial exposure to trichloroethane and deteriorated from mild stable cardiac failure to end stage cardiac failure after halothane anaesthesia for herniorrhaphy. Chronic cardiac toxicity is a previously unreported feature of this type of solvent exposure. Related compounds such as halothane may have a toxic interaction after exposure to trichloroethane.- - - - - - - - - - ranking = 1keywords = anaesthesia (Clic here for more details about this article) |
4/6. Acute amphetamine abuse. Problems during general anaesthesia for neurosurgery.A case of unsuspected acute amphetamine abuse by a 22-year-old girl which led to serious intracranial hypertension during anaesthesia for a neurosurgical procedure is described. It was difficult to maintained anaesthesia with an intermittent positive-pressure ventilation technique using muscle relaxants, N2O and O2 and supplements of fentanyl despite large doses of pancuronium and fentanyl. The differing effects of chronic and acute amphetamine dosage on anaesthetic requirements are reviewed.- - - - - - - - - - ranking = 6keywords = anaesthesia (Clic here for more details about this article) |
5/6. Intraoperative pulmonary oedema in a young cocaine smoker.This is a case of a 28-yr-old man who underwent general anaesthesia for emergency repair of a right lid laceration and lacrimal apparatus. Following induction of anaesthesia and local nasal application of phenylephrine (0.25%) he developed transient elevation of blood pressure, which was treated immediately with labetalol. Subsequently the patient developed acute pulmonary oedema which responded to treatment with morphine and furosemide. The diagnosis of pulmonary oedema was confirmed by blood gas studies, chest x-ray and serial echocardiograms. Subsequent investigation revealed that he was a cocaine user, as the urine tested positive for cocaine. Considering that the patient was young and otherwise healthy and that the hypertension was transient, it is unlikely that phenylephrine was the main cause of pulmonary oedema. Cardiac morbidity was most likely precipitated by the interaction of phenylephrine-induced hypertension with a cocaine-depressed myocardium.- - - - - - - - - - ranking = 2keywords = anaesthesia (Clic here for more details about this article) |
6/6. Unrecognized "crack" cocaine abuse in pregnancy.We report a case of "crack" cocaine abuse in a pregnant patient associated with haematuria, proteinuria, haemolytic anaemia, renal impairment, thrombocytopenia and pulmonary oedema. The case illustrates the problems for clinicians where unrecognized cocaine abuse interferes with the diagnosis and management of a complicated pregnancy. In addition, we discuss the principles for the safe conduct of anaesthesia in the pregnant cocaine abuser.- - - - - - - - - - ranking = 1keywords = anaesthesia (Clic here for more details about this article) |