Influence of preoperative anxiety on hypotension after spinal anaesthesia in women undergoing Caesarean delivery.

Background: We designed a prospective observational study to assess the effect of preoperative anxiety on hypotension after spinal anaesthesia.

Methods: After IRB approval and signed informed consent, 100 healthy term parturients undergoing elective Caesarean delivery under spinal anaesthesia were enrolled. Direct psychological assessments of preoperative anxiety were verbal analogue scale (VAS) (0-10) anxiety score and State-Trait Anxiety Inventory questionnaire (STAI-s); salivary amylase was measured as an indirect physical assessment of anxiety. Direct and indirect anxiety data were transformed into ordinal groups for low, medium, and high anxiety (VAS: low 0-3, medium 4-6, high 7-10; STAI-s: low <40, medium 40-55, high >55; log(10) salivary amylase: low <3, medium 3-4, high >4). Spinal anaesthesia was performed using hyperbaric bupivacaine 10 mg and fentanyl 20 μg. All patients received i.v. crystalloid 500 ml prehydration and 500 ml cohydration. Hypotension was treated by standardized protocol (fluid bolus and ephedrine or phenylephrine depending on maternal heart rate). Systolic arterial pressure (SAP) was measured at baseline and every minute after spinal anaesthesia. The effect of low, medium, and high anxiety groups on the maximum percentage change in SAP (%ΔSAP) was assessed (one-way analysis of variance, Tukey's honestly significant difference).

Results: Ninety-three patients were included in analysis. There was a significant effect of direct psychological measures of anxiety on %ΔSAP (VAS P=0.004; STAI-s P=0.048). There was a significant difference between low and high anxiety groups (VAS P=0.003; STAI-s P=0.038), but not between other anxiety groups. Salivary amylase did not correlate with %ΔSAP.

Conclusions: Preoperative anxiety assessed by VAS had a significant effect on hypotension after spinal anaesthesia.