Ketamine sequelae

Abstract

Emergence excitement or delirium and unpleasant postoperative dreams are the most undesirable sequelae of ketamine. Their occurrence has made it an unacceptable form of anaesthesia in adults, except when there is a specific indication for its use. Psychic sequelae occur more commonly in women than in men' and their incidence is related to the nature and duration of the and of the patient. A number of drugs have been given before, during or after anaesthesia to help reduce undesirable s e q~e I a e ,~* '~~ but it is difficult to compare their efficacy because of the varying types of operations and differing methods of interpretation of data. This paper reports a study in which ten drugs were given, alone or in combination, as intravenous premedication to a standard patient population anaesthet ised with ketamine alone and subjected to a standard follow-up. MethodPatients were undergoing morning minor gynaecological operations in one of two hospital units. The contraindications to the inclusion of a patient in the study were hypertension, a history of a cerebral vascular accident or psychiatric upset.Anaesthesia was induced with 2 mg/kg ketamine and maintained with intermittent doses in the region of 0.25 mg/kg as required. Arterial pressure and heart rate were measured at frequent intervals throughout and observations made during anaesthesia were standardised according to the scheme described by Dundee, Moore & Nich01l.~ Only the incidence of 'unacceptable' anaesthesia is presented here and this is defined as: 'Anaesthetic conditions making surgery difficult or impossible (hypertonus, involuntary movement, etc). or a sustained rise in systolic or diastolic pressure of 30+mmHg, or heart rate above 120 bpm.' These did not preclude the successful completion of the operation as operating conditions were often transformed by the use of nitrous oxide-oxygen with or without halothane or trichloroethylene.Patients were observed closely at the end of operation and the occurrence and severity of emergency delirium noted. This was classed as mild or severe, the latter implying screaming which would upset other patients or attendants. In all instances this was rapidly terminated by the intravenous injection of diazepam, droperidol or physostigmine.At a visit made 6 or 24 h after operation patients were questioned about the occurrence of 'dreams' which were classed as unpleasant or pleasant according to their content. At this visit patients were asked if, in the event of their

Recent Advances in Preventing and Managing Postoperative Delirium

“…Instead, dose-dependent increases were reported for postoperative hallucinations (18% in the placebo group, 20% in the 0.5 mg/kg ketamine group, and 28% in the 1.0 mg/kg ketamine group; P = 0.01) and nightmares (8% in the placebo group, 12% in the 0.5 mg/kg ketamine group, and 15% in the 1.0 mg/kg ketamine group; P = 0.03). These findings align with previously known psychoactive side effects of ketamine 33, 38, 39 . Thus, intraoperative ketamine probably does not prevent delirium; rather, ketamine may increase the risk of adverse perioperative psychoactive experiences.…”

The multiple faces of ketamine in anaesthesia and analgesia

“… 91 , 92 Propofol, lorazepam and diazepam are also effective. 93 In clinical practice, and in the opinion of some authors, the regular coadministration of benzodiazepines needs to be increased. 94 Finally, a recent trial ( n =100) reported that a positive persuasion may reduce unpleasant sensations.…”

Intravenous anaesthetics for short procedures

“…Nightmares may occur during recovery in up to 50% of adult^,^ but can be partly avoided by benzodiazepine premedication. [1][2][3][4][5][6][7][8][9][10][11][12][13][14] It increases muscle tone and is therefore unsuitable for procedures requiring muscle relaxation such as the reduction of fractures. Ketamine may cause a rise in intracranial and intraocular pressure, rendering it unsuitable for some patients or for neurological or ophthalmological procedures.…”