Effect of pre-operative patient anxiety on post-spinal shivering during elective cesarean delivery: a prospective observational study

Background: Shivering after spinal anesthesia is common during cesarean delivery (CD), and is thought to be primarily a thermoregulatory response. By inducing autonomic changes, pre-operative anxiety could alter the functioning of the thermoregulatory center, hence modifying the incidence and severity of obstetric post-spinal shivering. This prospective observational study was conducted to explore the relationship between pre-operative anxiety and obstetric post-spinal shivering.

Methods: Patients ≥18 years of age and scheduled for elective CD under spinal anesthesia were enrolled. Pre-operative anxiety was measured on the day of surgery using a visual analogue scale (VAS) and the Amsterdam Preoperative Anxiety and Information Scale (APAIS), and was correlated with the incidence of post-spinal shivering. Other possible risk factors for post-spinal shivering were explored using univariate and multivariate logistic regression models.

Results: Among the 150 participants, 46 (31%) experienced post-spinal shivering. The relative risk of intra-operative shivering in those with high APAIS pre-operative anxiety was 2.76 (95% CI 1.55 to 4.90; P = 0.0005). Younger patient age (aOR 0.91, 95% CI 0.83 to 0.98; P = 0.02), higher APAIS anxiety score (aOR 1.21, 95% CI 1.06 to 1.37; P = 0.005), higher VAS anxiety score (aOR 1.48, 95% CI 1.24 to 1.78; P < 0.001) were independent risk factors for post-spinal shivering.

Conclusions: High pre-operative anxiety and younger patient age were independent risk factors for post-spinal shivering during elective CD. Targeted interventions to reduce pre-operative patient anxiety might have a positive impact in decreasing the incidence of intra-operative post-spinal shivering in this patient population.