Aufwachverhalten und psychomimetische Reaktionen nach S-(+)-Ketamin

Abstract

Ketamine is a racemic mixture containing equal parts of S-(+)-ketamine and R-(-)-ketamine. Their potency relation is approximately 4:1. In early human studies S-(+)-ketamine was presumed to produce the desired anaesthetic effects and R-(-)-ketamine the undesired psychic emergence reactions. Therefore, ketamine was compared in a number of randomised studies in volunteers and patients with racemic ketamine. This review addresses the impact of S-(+)-ketamine on recovery from anaesthesia, incidence and content of vivid dreams, and other side effects. The dose relation applied in the studies was 1:2. With only one exception, the recovery phase was clearly shorter after S-(+)-ketamine compared to racemic ketamine irrespective of its application as a single bolus, a bolus followed by continuous infusion, or an intramuscular injection. However, the incidence of psychic emergence reactions was lower after S-(+)-ketamine in only a single study. In conclusion, S-(+)-ketamine should be always combined with a hypnotic or sedative drug in clinical anaesthesia.

Prehospital analgesia using nasal administration of S-ketamine – a case series

“…S-ketamine was developed to decrease psychotomimetic side-effects of racemic ketamine but a review suggests that this is not clearly the case [7]. Another side-effect of ketamine as well as S-ketamine is hypersecretion.…”

Anaesthesia with midazolam and S‐(+)‐ketamine in spontaneously breathing paediatric patients during magnetic resonance imaging

“…If required, an additional bolus of methohexital was given before transfer to the scanner room. Group 2 received the sedation protocol consisting of a rectal bolus of 0.5 mg·kg −1 midazolam and 5 mg·kg −1 S‐(+)‐ketamine [equipotent to 10 mg·kg −1 racemic ketamine ( 6)], insertion of an intravenous cannula and two nasal prongs for additional oxygen supply (2–3 l·min −1 ) and sample aspiration for continuous monitoring of the nasopharyngeal endtidal pCO 2 signal. Additional intravenous boluses of 0.05 mg·kg −1 midazolam and 0.25 mg·kg −1 S‐(+)‐ketamine were administered until adequate immobilization for scanning was achieved.…”

“…In 1997, one of the two optical enantiomers contained in the racemic mixture ketamine became available in purified form. Several studies revealed clinical superiority of S‐(+)‐ketamine compared to its optical enantiomer R‐(−)‐ketamine concerning anaesthetic potency ( 5), recovery time ( 6) and neuroprotective effects ( 7). Thus, a sedation technique based on S‐(+)‐ketamine and midazolam might combine the well known advantages of ketamine [oral and rectal route of administration ( 8, 9), large margin of safety concerning cardiovascular and respiratory depression ( 10)] with a potential reduction in adverse effects (i.e.…”

Die geschichtliche Entwicklung der Intensivmedizin in Deutschland

“…Eine verkürzte Aufwachphase im Vergleich zum bisher verfügbaren Razemat wird auch dem S-(+)-Ketamin zugesprochen, neben einer möglicherweise geringeren Ausprägung der psychischen Aufwachreaktion [15,25]. Diese Eigenschaften und die höhere analgetische und anästhetische Potenz des S-(+)-Enantiomers erneuern das intensivmedizinische Interesse an diesem Analgosedativum, wobei gerade im intensivmedizinischen Bereich eine Halbierung der erforderlichen Substanzmenge einen wichtigen pharmakokinetischen Fortschritt darstellt.…”