How to better assess street fitness after propofol conscious sedation

Objectives: Intravenous sedation with propofol has been widely used in dentistry. Although appropriate evaluations for street fitness are fundamental, few reports have discussed this issue after propofol sedation. We therefore investigated the relationship among sedation score, propofol blood concentration and psychomotor function during and after propofol conscious sedation. Methods: Ten consenting male volunteers classified in ASA I participated in the study. Subjects received propofol or physiological saline solution (PSS) in a randomized manner. Following a bolus injection (0.05ml/kg), propofol or PSS was continuously infused for 30 min (0.3~0.6ml/kg/h). In the propofol group, sedation level was maintained at level 3 (optimum level as conscious sedation is level 3; level 4 is deep sedation). Observations started immediately before the bolus injection (Control) and finished 60 min after the infusion. Variables measured included: blood pressure, heart rate, arterial oxygen saturation, respiratory rate, end-tidalCO2 tension, sedation score, propofol blood concentration, bispectral index (BIS) value, psychomotor function test (Trieger Dot Test (TDT), Stabilometry), Walk test. Results: Significant differences were observed in BIS values and plot error ratios in the TDT at 5 min, gravity oscillation area at 10 min, and subjective feeling of reeling at 15 min after the stop of the infusion between two groups. Sedation score in the propofol group recovered to the control level 45 min after the infusion. Compared with recoveries of psychomotor function and BIS, recovery from sedation and walk test were delayed. Conclusions: The recovery of subjective symptoms at rest and at walk test after sedation was slower than that of psychomotor functions and BIS value. Although recoveries of these functions are fundamental to assess street fitness after conscious sedation, subjective symptoms may affect the decision to allow discharge. Therefore patient's sedation score and walk test should be taken into account to assess street fitness.