Sensory Block Height and Risk of Maternal Fever in Epidural Labour Analgesia: A Prospective Cohort Study.

BACKGROUND

Epidural anaesthesia is commonly utilized for pain relief during labour. However, it has been observed that this method can lead to maternal fever (temperature≥38 °C). The mechanism of epidural-related maternal fever (ERMF) remains unclear. This study aims to explore the correlation between the level of sensory blockade and the occurrence of ERMF.

METHODS

This cohort study included primigravid women who received patient-controlled epidural analgesia (PCEA). We employed a wireless continuous temperature-monitoring device to capture minute-by-minute fluctuations in maternal temperature. Additionally, various indicators pertaining to the mother, neonate, and anaesthesia were recorded throughout the labour process. Receiver operating characteristic curves were used to evaluate the predictive performances of the sensory block level and duration of block level for fever. Logistic regression was used for multifactorial analyses. Propensity score matching was employed to eliminate endogeneity and control confounding factors.

RESULTS

The study included a sample of 953 primigravid women, among whom an average of 29.8% (284/953) experienced intrapartum fever. The highest level of sensory block was significantly higher in febrile women than in nonfebrile women. Women with labour analgesia may be more prone to fever when the duration of block level above innervation level of thoracic 8 was longer than 135 minutes. Factors influencing ERMF include the highest level of sensory blockade, duration of block level (above T8), and the meconium-stained amniotic fluid (MSAF).

CONCLUSION

During epidural labour analgesia, the highest level of sensory block was significantly higher in febrile women than in nonfebrile women. When the maternal sensory block plane surpasses the innervation level of thoracic 8 and persists for longer than 135 minutes, the likelihood of maternal fever increased. Therefore, maintaining the maternal sensory block plane below T8 may reduce fever.