[Assessment of anxiety, pain and its management in prenatal diagnosis procedures]. / Évaluation de l'anxiété, de la douleur, et de leur prise en charge dans les gestes de diagnostic anténatal.

UNLABELLED: Invasive prenatal diagnosis procedures are numerous and more or less painful and stressful. The purpose of this study was to investigate maternal perception of both anxiety and pain before and after amniocentesis (AC) or transabdominal chorionic villus sampling (CVS), to determine factors associated with pain and anxiety, and to evaluate the pain support. This is a prospective study evaluating the professional practices at CHRU of Lille between March and May 2009 with 132 AC and 22 CVS by aspiration. An original questionnaire has been elaborated in three parts: the first one fulfilled by patients before the procedure, the second one, after the procedure, and the last one by the medical team. Statistical comparisons have used the Chi(2) test, the Fisher exact test, the Student's t test and the U test of Mann Whitney. RESULTS: The anxiety level is high but does not differ between the two groups AC and CVS. CVS are more painful than AC (EVA 5.77 versus 3.07, P<0.0001). No predisposing factor for anxiety has been found. On the other side, procedures are more painful when they are long lasting, considered difficult by the medical team, when needles used are large, the number of needle insertions increases, puncture is performed along a side of the uterus, patients are anxious, and then procedure indication is an hygroma. Patients are satisfied in 98.7% of cases of the support of the medical team. Few drug treatments was prescribed (only 4.5%), however, patients are generally applicant. CONCLUSION: An analgesic, anxiolytic, or a relaxation technique can be proposed to anxious and applicant patients undergoing CVS. Technical conditions of the procedure are more difficult to improve, however, we should use if possible thinner needles, and avoid, wherever technically possible, the punctures on the lateral side of the uterus. Finally, further studies seem necessary for the evaluation of a treatment protocol.

Quantitative analysis of intestinal motor patterns: spatiotemporal organization of nonneural pacemaker sites in the rat ileum.

BACKGROUND & AIMS: Intestinal contractions are triggered by electric activity of pacemaker cells within the smooth muscle. However, the precise spatial organization of the pacemaker system is unknown. We directly assessed the spatiotemporal organization of pacemakers by video image analysis combined with manometry and electromyography. METHODS: Isolated segments of rat ileum were perfused arterially with oxygenated fluorocarbon solution and luminally with saline. Luminal end pressures, extracellular electric activity, and images of the intestine were recorded simultaneously. Tetrodotoxin, N(G)-nitro-L-arginine methyl ester (L-NAME), L-arginine, and eserine were administered arterially. RESULTS: Myogenic contractions originated in discrete areas (dominant pacemakers) and propagated faster in aboral than in oral direction. Dominant pacemakers were distributed along the intestine at regular intervals. The preparations were mostly driven by 1 pacemaker at the time, but 2 or 3 pacemakers with different frequencies could be active simultaneously. Tetrodotoxin decreased aboral propagation velocity and revealed multiple regularly spaced pacemaker areas. Eserine increased, whereas L-arginine decreased, their frequency. After L-NAME, pacemaker activity increased and isolated pacemakers with higher frequency appeared. CONCLUSIONS: Nonneural pacemakers in rat ileum are functionally organized not as a continuous system but show a segmental arrangement, spatially and temporally modulated by neural activity.

Non-linear cortico-cortical interactions modulated by cholinergic afferences from the rat basal forebrain.

In the adult rat most of basal forebrain cholinergic neurons (BFCN) express the low-affinity p75 nerve growth factor recceptor (NGFr). The immunotoxin 192 IgG-saporin (SAP) provokes a selective loss of NGFr-positive BFCN, somewhat similar to the loss of integrity of BFCN associated with human senile dementia of Alzheimer's type, whereas NGF exerts a trophic action on BFCN. Cortico-cortical interactions are modulated by cholinergic projections of BFCN and it is proposed that alterations of these projections by SAP and by NGF produce opposite effects. This hypothesis was tested by recording multiple local field potentials (LFPs) in the rat temporal cortex and applying bispectral analysis to measure phase-coupled frequencies, somewhat analogous to frequencies of resonance. Choline acetyltransferase (ChAT) activity was measured in the septal area in order to assess the effects of the treatments. NGF-treatment increased ChAT activity by 45% and frequencies of non-linear coupling were shifted towards frequencies higher than 70 Hz, thus suggesting the presence of increased functional interactions in the short range. By contrast, SAP provoked a decrease of nearly 40% in ChAT activity and an increase of phase-coupling in the low frequencies (< 50 Hz), being interpreted as a decreased functional cortico-cortical interaction. Bispectral analysis revealed features of the effect of BFCN on cortical activity that could not be observed by other means and offers as a valuable tool of study that could be extended to the EEG of Alzheimer's patients.

Corticofugal modulation of functional connectivity within the auditory thalamus of rat, guinea pig and cat revealed by cooling deactivation.

Microelectrode recordings were simultaneously performed at multiple sites in the medial geniculate body (MGB) of anesthetized cats, rats and guinea pigs. We studied the effect of cortical deactivation on the association of neural activity within the thalamus during spontaneous activity. The corticofugal influence was suppressed by temporary cooling of the auditory cortex. Pairs of spike trains recorded from the same electrode were distinguished from cases where units were in MGB but recorded with different electrodes. Time domain analyses included crosscorrelations and search for precise repetition of complex spatiotemporal firing patterns of reverberating thalamic circuits. As a complementary approach we performed bispectral analyses of simultaneously recorded local field potentials in order to uncover the frequency components of their power spectra which are non linearly coupled. All results suggest that new functional neuronal circuits might appear at the thalamic level in the absence of input from the cortex. The newly active intrathalamic connections would provide the necessary input to sustain the reverberating activity of thalamic cell assemblies and generate low frequency non-linear interactions. The dynamic control exerted by the cortex over the functional segregation of information processing carried out in the thalamus conforms with theoretical neural network studies and with the functional selectivity-adaptive filtering theory of thalamic neuronal assemblies. Although this general conclusion remains valid across species, specific differences are discussed in the frame of known differences of the microcircuitry elements.

Comfort and safety in eye surgery under local anaesthesia.

The study consisted of two parts: 1. The standard system in use at our hospital for gas delivery under the drapes during eye surgery under local anaesthesia was compared with one incorporating a venturi. 2. The oxygen concentration at the operation site was measured with three methods of draping using the two systems. Twenty-three patients and thirty-one volunteers from the operating room staff were subjected to operating conditions and gas concentrations and certain vital signs measured using both systems. The subjective response of the volunteers, none of whom had blocks or premedication, was noted. The burden of rebreathing seen with a significant proportion of cases using 6 l/min of fresh gas flow was not seen when the venturi system was used. The safety from fire hazard using 26% oxygen and diathermy was demonstrated with occlusive and free draping.

Origins of motility patterns in isolated arterially perfused rat intestine.

BACKGROUND/AIMS: Assessment of the neuromuscular control of small intestinal motility and movement of luminal contents is hampered in vivo by measurement techniques and in vitro by tissue viability. The aim of this study was to establish the structural and functional integrity of an isolated segment of rat ileum and characterize its motility. METHODS: Segments of rat ileum were perfused arterially with oxygenated fluorocarbon and luminally with saline. Oral and aboral pressures were correlated with conformational changes detected by concurrent video imaging. RESULTS: Light and electron microscopy showed no neuromuscular abnormalities after experiments, and acetylcholine-induced pressure amplitudes were unchanged during experiments. Under basal conditions, low-frequency contractions showing constant frequency (0.27/min) and amplitudes (oral, 17 hPa; aboral, 15 hPa) corresponded to luminally occlusive aborally propagated contractions, which were eliminated by tetrodotoxin. High-frequency contractions with a constant frequency (27/min) were also seen; their basal amplitude (0.3 hPa) increased immediately before and after low-frequency contractions and after tetrodotoxin. Tetrodotoxin also increased basal intestinal tone. CONCLUSIONS: An isolated, arterially perfused segment of rat ileum retains structural and functional integrity. It shows low-frequency propulsive contractions, controlled by the enteric nervous system, and myogenic high-frequency contractions, probably subject to tonic neural inhibition.