Rate of caesarean sections according to the Robson classification: Analysis in a French perinatal network - Interest and limitations of the French medico-administrative data (PMSI).

INTRODUCTION: The objective of our study was to determine, in accordance with WHO recommendations, the rates of Caesarean sections in a French perinatal network according to the Robson classification and determine the benefit of the medico-administrative data (PMSI) to collect this indicator. This study aimed to identify the main groups contributing to local variations in the rates of Caesarean sections. MATERIAL AND METHODS: A descriptive multicentric study was conducted in 13 maternity units of a French perinatal network. The rates of Caesarean sections and the contribution of each group of the Robson classification were calculated for all Caesarean sections performed in 2014. The agreement of the classification of Caesarean sections according to Robson using medico-administrative data and data collected in the patient records was measured by the Kappa index. We also analysed a 6 groups simplified Robson classification only using data from PMSI, which do not inform about parity and onset of labour. RESULTS: The rate of Caesarean sections was 19% (14.5-33.2) in 2014 (2924 out of 15413 deliveries). The most important contributors to the total rates were groups 1, 2 and 5, representing respectively 14.3%, 16.7% and 32.1% of the Caesarean sections. The rates were significantly different in level 1, 2b and 3 maternity units in groups 1 to 4, level 2a maternity units in group 5, and level 3 maternity units in groups 6 and 7. The agreement between the simplified Robson classification produced using the medical records and the medico-administrative data was excellent, with a Kappa index of 0.985 (0.980-0.990). CONCLUSION: To reduce the rates of Caesarean sections, audits should be conducted on groups 1, 2 and 5 and local protocols developed. Simply by collecting the parity data, the excellent metrological quality of the medico-administrative data would allow systematisation of the Robson classification for each hospital.

Some aspects of the physiological role of ion channels in the nervous system.

Recent analyses of the genomes of several animal species, including man, have revealed that a large number of ion channels are present in the nervous system. Our understanding of the physiological role of these channels in the nervous system has followed the evolution of biophysical techniques during the last century. The observation and the quantification of the electrical events associated with the operation of the ionic channels has been, and still is, one of the best tools to analyse the various aspects of their contribution to nerve function. For this reason, we have chosen to use electrophysiological recordings to illustrate some of the main functions of these channels. The properties and the roles of Na+ and K+ channels in neuronal resting and action potentials are illustrated in the case of the giant axons of the squid and the cockroach. The nature and role of the calcium currents in the bursting behaviour of the neurons are illustrated for Aplysia giant neurons. The relationship between presynaptic calcium currents and synaptic transmission is shown for the squid giant synapse. The involvement of calcium channels in survival and neurite outgrowth of cultured neurons is exemplified using embryonic cockroach brain neurons. This same neuronal preparation is used to illustrate ion channel noise and single-channel events associated with the binding of agonists to nicotinic receptors. Some features of the synaptic activity in the central nervous system are shown, with examples from the cercal nerve giant-axon preparation of the cockroach. The interplay of different ion conductances involved in the oscillatory behaviour of the Xenopus spinal motoneurons is illustrated and discussed. The last part of this review deals with ionic homeostasis in the brain and the function of glial cells, with examples from Necturus and squids.

Role of ligand-gated ion channels in the swimming behaviour of Xenopus tadpoles: experimental data and modelling experiments.

The swimming behaviour of lower vertebrates has been used as a model to study the function of simple neuronal circuits. Good examples are the lamprey and the Xenopus tadpole. In these two cases, glutamate-activated NMDA receptors are involved, and the relative importance of the NMDA and non-NMDA receptors as well as the involvement of other ion channels has been studied using a combination of electrophysiological recordings and modelling experiments, but little attention had been paid to their evolution during development. In the present experiments, which have been performed on Xenopus embryos from stages 31 to 42, we have probed the relative importance of the two categories of receptors using selective blockers [respectively dl-2-amino-5-phosphonovaleric acid (APV) and 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX)]. The sensitivity of the swimming behaviour to APV was found to increase during development and that to CNQX to decrease. Furthermore, it has been observed that the spike activity recorded from the ventral roots is more complex in late embryonic stages that in early embryos. These modifications are associated with changes of the neuronal circuit, some of which correspond to a lengthening of the axon and an increased complexity of the dendritic tree of the motoneurons. We have incorporated these modifications in a simplified model of the central pattern generator built with Neuron software. The results indicate that at least part of the observed changes can be associated with changes in the length of the dendrites and axons.

N-Methyl-D-aspartate-induced oscillations in whole cell clamped neurons from the isolated spinal cord of Xenopus laevis embryos.

The patch-clamp technique was used to measure the effect of N-methyl-D-aspartate (NMDA) on Xenopus embryonic neurons in an isolated, but intact spinal cord. Whole cell recordings were done at external calcium concentrations of 1 mM. NMDA alone (50-200 microM) or in association with 10 microM serotonin or glycine induced oscillatory activity in most presumed motoneurons, which were therefore considered part of rhythm generating networks. In the presence of TTX, one-half of these neurons maintained this activity. The oscillations fell into two main categories: voltage-dependent, low-frequency (0.3-0.5 Hz) and voltage-independent, high-frequency (3-8 Hz) oscillations. NMDA alone induced TTX-insensitive oscillations in one-third of the neurons; however, the percentage of neurons showing oscillations was greater in the presence of exogenous 5-hydroxytryptamine (5-HT) or glycine. Because these observations were made at embryonic stages where little or no serotonergic innervation exists, it is likely that NMDA-induced intrinsic oscillatory activity in Xenopus embryonic neurons does not require 5-HT.

Doppler ultrasound of the prostate in normal dogs and in dogs with chronic lymphocytic-lymphoplasmocytic prostatitis.

The prostate gland of 11 normal dogs and five dogs with histologically confirmed chronic lymphocytic or lymphoplasmocytic prostatitis were imaged with grey-scale and Doppler ultrasound. Three vessel types (prostatic artery, capsular artery and parenchymal artery) were identified with color Doppler and the resistive index and maximum and minimum velocities were measured with pulsed wave Doppler. No differences between normal dogs and dogs with prostatitis was identified in either grey-scale ultrasound or in any Doppler parameters measured. Regardless of histologic diagnosis, acepromazine (0.05 mg/kg i.v.) caused a significant decrease in capsular artery maximum and minimum velocities and prostatic artery resistive index. This study establishes normal Doppler ultrasound parameters for the intact male canine prostate gland. Additional studies are necessary to further evaluate the clinical utility of Doppler ultrasound in canine prostatic diseases.