Shaking rigors in parturients

To describe the frequency, duration and timing of shaking rigors during parturition and their associations with several clinical variables.

A total of 467 term, singleton paturients at a single hospital over a 13-month recruitment period were observed by their labor nurses for shaking rigors. Thirteen clinical variables, including length of labor, were also recorded. Multiple regression procedures were used to evaluate associations with presence or absence, number and total duration of rigors. The relationship in time between shaking rigors and sentinel events in labor was also examined. With this sample size, we had > 80% power to detect differences as small as 0.26 effect size units for continuous measures, or ORs of 1.75 or greater for categorical measures, when comparing patients with and without rigors.

In total, 57% of parturients experienced at least 1 rigor. Epidural usage was related to risk, duration and number of rigors. Increased maximum temperature was associated with an increased chance of rigors. Epidural, birth and maternal fever were antecedent events.

Over half of parturients experienced shaking rigors. Epidural administration and fever were associated with an increased probability of rigors and an increased number of episodes.