Does anxious patients require more propofol at induction?

Abstract

Background: Preoperative anxiety increases postoperative analgesic requirement, prolongs hospital stay and results in poor patient satisfaction. We investigated the correlation of preoperative state of anxiety on propofol requirement at induction of anesthesia and vital signs.
Methodology: This prospective study recruited 52 ASA I and II patients scheduled for surgery under general anesthesia. The Malay version of Generalized Anxiety Disorder-7 questionnaire was used to assess preoperative anxiety state. Anesthesia was induced with propofol infusion using the Schnider protocol to achieve target plasma concentration of 4 µg/ml. Baseline systolic blood pressure and heart rate (HR) prior to induction were recorded. The amount of propofol required until loss of consciousness, and bispectral index (BIS) values immediate post induction were recorded. Pearson’s correlation coefficient was used to assess relationship.
Results: There was no correlation between the preoperative state of anxiety and propofol requirement at induction (r = 0.07, p = 0.580), and systolic blood pressure prior to induction (r = 0.23, p = 0.101). However, weak positive correlations were detected between preoperative state of anxiety and the HR prior to induction (r = 0.27, p = 0.050), and with BIS at loss of consciousness (r = 0.32, p = 0.026).However, no correlation was seen between propofol requirement for induction with HR prior to induction (r = 0.13, p = 0.37). Anxious patients were unable to sleep well pre-operatively (p = 0.009).
Conclusion:  Preoperative state of anxiety does not influence propofol requirement for induction of anesthesia.
Citation: Masri SNNS, Rahman RA, Masdar A, Mat WRW, Nor NM, Izaham A. Does anxious patients require more propofol at induction? Anaesth Pain & Intensive Care 2018;22(4):419-423
Received: 28 Dec 2017, Reviewed: 25 May 2018, Corrected: 25 Jul 2018, Accepted 7 Jan 2019