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).