Interpretation
Nomograms and risk scores are increasingly used by clinicians. These mathematical models allow an individual prognosis for each patient. In obstetrics, several of these models were developed to predict different risks: risk of low umbilical artery pH during labour, risk of preterm delivery, and risk of shoulder dystocia, among others24–26.
The ultimate objective of this risk score of failed mid-cavity VAD is primarily to improve maternal and neonatal outcomes. It could also improve the childbirth experience for the parents and the maternity organization. Two noteworthy situations could be made rarer by this score. First, emergency transfer to a surgical room for an emergency C-section under general anaesthesia after a failed OVD performed without any anticipation of the potential C-section is a stressful situation for obstetrical and anaesthesia teams. This situation is associated with poorer maternal and neonatal outcomes and can be a negative childbirth experience for the parents. Second, the situation involving a transfer to an operating theatre with the extension of epidural analgesia and equipment preparation for C-section followed by an ultimately successful OVD is associated with poorer neonatal outcomes because of the transfer delay and unnecessary use of two delivery rooms and materials.
As specified by the RCOG, our neonatal outcomes were poorer when the women were unnecessarily transferred to an operating theatre for an ultimately successful VAD10,13. As shown in the literature, our maternal and neonatal outcomes were worse in the “failed VAD” group than in the “successful VAD” group6. The anticipated extension of epidural analgesia before the C-section decision is poorly described in the literature: the majority of articles concern the complete extension carried out after the C-section decision that can be too late, leading to general anaesthesia in the case of an emergency C-section27,28. However, we demonstrated that the anticipated extension of epidural analgesia was significantly associated with a decrease in the delay of C-section completion and with a decrease in the rate of general anaesthesia for the mother. This could therefore reduce maternal morbidity related to emergency general anaesthesia, including aspiration pneumonitis, failed endotracheal intubation, respiratory depression, and laryngeal damage29.
We plan to test this score by comparing two groups: a group in which the obstetrician uses the score and a group in which the obstetrician makes a decision without using the score. The following will be compared between both groups: maternal and neonatal outcomes; the rates of successful VADs, failed VADs and direct C-sections; and the expected error rate (introduction of additional precautions followed by a successful VAD/absence of additional precautions followed by a failed VAD).