Self-administration of midazolam for postoperative anxiety: a double blinded study

Abstract

Anxiety is almost inevitably present in patients facing surgery. The optimal management of postoperative pain requires the acknowledgement of perioperative anxiety and the inclusion of pharmacological and/or non-pharmacological means of alleviating the fear and worry inherent in the surgical experience. In a double-blind randomized design, 39 patients undergoing total abdominal hysterectomies were given postoperative access to a standard patient-controlled analgesia (PCA) morphine pump for pain and a PCA pump dispensing either low-dose midazolam or saline for anxiety. Measures of anxiety and pain were completed pre-operatively and for 2 days postoperatively. Utilization of morphine and ‘anxiolytic agent’ were recorded. Analysis of covariance was applied to the data to control for the imbalance of cancer patients between the 2 groups. While both groups of patients chose to utilize their ‘anxiety pump’ throughout the study, those patients receiving midazolam had significantly lower postoperative Spielberger State Anxiety scores and visual analogue scale anxiety scores. Patient-controlled midazolam in doses used in this study were safe and effective in managing anxiety but did not influence pain scores or the amount of PCA morphine patients used. Pre-operative levels of depression were significantly associated with postoperative pain levels independent of treatment group or cancer diagnosis.