Ketamine anesthesia for short transurethral urologic procedures.

Ketamine (K) is a good analgesic and anesthetic agent in short procedures, but the associated cardiovascular responses and emergence reactions limit its use. Benzodiazepines have been used to improve recovery with favourable reports for midazolam (M). Methylphenidate (MPH), the mild CNS stimulant, improves behaviour and mental concentration and can be used to improve recovery from K anesthesia. This was tested, alone and in combination with M by a double-blind study in 30 patients subjected to short transurethral urologic procedures. Patients were randomized into 3 equal groups to receive K-MPH, K-M or K-M-MPH. M (7.5 mg) was mixed with K and MPH (20 mg) was given at the end of urologic procedures. Perioperative monitoring included pulse rate, blood pressure, ECG, and plasma catecholamines. Recovery was assessed by a triad VAS and recovery area was calculated. Distribution-free statistics were used to assess intergroup differences of similar variables. Ketamine produced satisfactory anesthesia for short transurethral urologic procedures. Addition of M did not change the cardiovascular responses of K but resulted in smooth recovery with no changes in the recovery scores. MPH did not improve the recovery scores but increased the incidence of vomiting, excessive talking, and limb movements.