[The effect of low droperidol dosages on postoperative anxiety, internal tension, general mood and PONV].

BACKGROUND

Droperidol even in low doses such as 0.5 mg to 1.25 mg can increase postoperative anxiety and state of tension. The aim of this study was to determine whether these side effects occur frequently following low-dose droperidol and to see whether these are dose related.

METHODS

184 female in- and outpatients ASA grade 1 and 2 undergoing gynaecological laparoscopy were recruited to this prospective, double-blind study. General anaesthesia was standardized (induction with thiopentone, fentanyl 2 micrograms/kg and vecuronium 0.1 mg/kg, tracheal intubation, maintainance with enflurane in N2O/O2). Patients were randomly allocated to receive saline (n = 45), 0.625 mg (n = 46), 1.25 mg (n = 47) or 2.5 mg (n = 46) droperidol i.v. 10 minutes before the end of surgery. 1,3,6, and 24 hours postoperatively, the patients' anxiety, state of tension and overall mood was evaluated using two psychological questionnaires which had been tested for the perioperative period (Erlanger anxiety and tension-scale/BSKE-EWL-test). Sedation was evaluated by the staff of the recovery room. In addition, postoperative nausea and vomiting (PONV) was assessed using a 100 mm visual analogue scale and by counting the episodes of retching or vomiting. PONV was then rated over the whole observation period as none, mild, moderate or severe using a fixed scoring algorithm. Statistical analysis was performed using the ANOVA and the chi2-test.

RESULTS

The patients did not differ with regard to biometric data, duration of surgery and anaesthesia. The postoperative scores for anxiety, state of tension and overall mood were not different between the groups at any observation time (Fig. 1: anxiety and tension: P = 0.5687; figure 2: overall mood: P = 0.0647). Quality of sleep in the first night after surgery was the same in all groups (Table 2 and 3). Sedation was not significantly different (Table 4; P = 0.0704). Furthermore, duration of stay in the recovery room did not differ (P = 0.4353). On the other hand, three patients from the 2.5 mg droperidol group had to stay unexpectedly on the ward overnight, because they had been too much sedated to be discharged at home. This was not the case with any patient from the other groups. Compared to placebo, PONV over the whole 24 h observation period was significantly reduced by droperidol (Fig. 3; P = 0.0338): completely free from PONV: placebo: 41.3%, 0.625 mg droperidol: 67.4%, 1.25 mg droperidol: 53.2%, 2.5 mg droperidol: 71.7%. Also the severity of PONV was reduced.

CONCLUSION

In gynaecological laparoscopy under general anaesthesia with tracheal intubation, we recommend droperidol 0.625 mg in the prevention of PONV, as it reduces PONV as well as 2.5 mg with no severe sedation in this dosage. Psychological side effects did not occur more frequently after droperidol compared to placebo in any of the investigated dosages.