Paradoxical Anesthetic Reactions, Dr. Inoue

Akiko Inoue, DO

“Increase of Paradoxical Excitement Response During Propofol-induced Sedation in Hazardous and Harmful Alcohol Drinkers” by S. Jeong; H.G> Lee; W. M. Kim; C.W. Jeong; S. H. Lee; M. Yoon; J. I. Choi

Br J Anesth. 2011; 107(6):930-933.

This is a prospective observational study of two consecutive sessions (study 1 n=70, study 2 n=120) on a total of 190 patients who underwent elective knee joint surgery in the supine position under spinal anesthesia.  They were asked 10 questions related to frequency of alcohol consumption, alcohol-related problems, and dependence symptoms.  The sum of scores to these questions ranged from 0-40 and based on the scores the subjects were categorized either hazardous and harmful drinkers (HD) or non hazardous drinkers (NHD).  Paradoxical excitement responses were scored by response such as increased talkativeness, brief spontaneous movement without repostioning (mild), restlessness, loss of cooperation, spontaneous movements requiring repositioning, (moderate), and agitation and spontaneous movements with a need to restrain the patient (severe).  The response was observed for 30 min and scored every 5 min.  In the first study the propofol infusion was started at the target effect-site concentration of 2.0 mcg/ml until BIS score reached 80, then it was controlled to maintain the BIS score in the range 70-80. In the second study the effect-site concentration was fixed in the whole study time at 0.8 mcg/ml (study 2/Low; Group HD=30, Group NHD=30) or 1.4 mcg/ml (study 2/High; Group HD=30, Group NHD=30.   The results were analyzed using SPSS and X² or Fisher’s exact test. In study 1 the incidence of paradoxical excitement response was higher in Group HD than in Group NHD (71.4% vs 43.8%; P=0.022), an odds ratio of 3.2 [95% confidence interval (CI): 1.2–8.8].  In study 2 the incidence was higher in Group HD (70.0% vs 34.5%; P=0.006), an odds ratio of 4.4 (95% CI: 1.5–13.2) only at high target effect-site concentration but not at the low concentration.  The incidence of moderate-to-severe response was significantly higher in Group HD of both study 1 (28.6% vs 3.1%; P=0.0005) and study 2 at the higher infusion rate (23.3% vs 3.4%; P=0.029).   Thus, authors concluded that “paradoxical excitement occurred more frequently and severely in hazardous and harmful alcohol drinkers than in social drinkers during propofol-induced moderate-to-deep sedation but not during light sedation”.  Some of the limitations of the study are 1) not a randomized double blind study 2) lack of diagnostic criteria for paradoxical response thus it may be overestimating the incidence.  However, this study is significant in suggesting that hazardous and harmful alcohol use may be one of the risk factors for developing paradoxical excitement responses during propofol-induced sedation.