2. Universidad Cardenal Herrera-CEU

Background: We designed a device to close accidental dural puncture via the offending puncturing epidural needle directly after diagnosis of the puncture and before removing the needle. The aim of this study was to quantify this device's ability to seal cerebrospinal fluid leakage. Methods: Forty-six anesthetized adult sheep were studied in a single-blind randomized controlled fashion in two equal groups.An intentional dural puncture was performed with an 18-gage Tuohy needle on all the sheep between L6 and S1 levels. Contrast medium was injected through the needle. Twenty-three animals receive treatment with the sealing device. Two minutes after device placement, or dural puncture in the control group, a CT scan was performed on the animals to estimate contrast material leakage. A region of interest (ROI) was defined as the region that enclosed the subarachnoid space, epidural space, and neuroforaminal canal (the vertebral body above and half of its equivalent height in sacrum below the puncture site). In this region, the total contrast volume and the volumes in the epidural space (EPIDURAL) were measured. The primary outcome measure was the EPIDURAL/ROI ratio to ascertain the proportion of intrathecally injected fluid that passed into the epidural space in both groups. The secondary outcomes were the total amount of contrast in the ROI and the EPIDURAL. Results: The device was deployed successfully in all but two instances, where it suffered from manufacturing defects.Leakage was less in the study group (1.0 vs 1.4 mL, p=0.008). The median EPIDURAL/ROI ratio was likewise less in the study group (29 vs 46; p=0.013; 95% CI (-27 to -3.5)). Conclusion: This novel dural puncture-sealing device, also envisaged to be used in other comparable iatrogenic leakage scenarios to be identified in the future, was able to reduce the volume of cerebrospinal fluid that leaked into the epidural space after dural puncture. The device is possibly a valuable way of preventing fluid leakage immediately after the recognition of membrane puncture.

Background: Standing surgery in horses combining intravenous sedatives, analgesics and local anaesthesia is becoming more popular. Ultrasound guided (USG) peribulbar nerve block (PB) has been described in dogs and humans for facial and ocular surgery, reducing the risk of complications versus retrobulbar nerve block (RB). Objective: To describe a technique for USG PB in horse cadavers. Methods: Landmarks and PB technique were described in two equine cadaver heads (Phase 1), with computed tomography (CT) imaging confirming contrast location and spread. In Phase 2, ten equine cadaver heads were randomised to two operators naïve to the USG PB, with moderate experience with ultrasonography and conventional “blind” RB. Both techniques were demonstrated once. Subsequently, operators performed five USG PB and five RB each, unassisted. Contrast location and spread were evaluated by CT. Injection site success was defined for USG PB as extraconal contrast, and for RB intraconal contrast. Results: Success was 10/10 for USG PB and 0/10 for RB (p < 0.001). Of the RB injections, eight resulted in extraconal contrast and two in the masseter muscle (p = 0.47). Conclusions: The USG PB had a high injection site success rate compared with the RB technique; however, we cannot comment on clinical effect. The USG technique was easily learnt, and no potential complications were seen. The USG PB nerve block could have a wide application for use in horses for ocular surgeries (enucleations, eyelid, corneal, cataract surgeries, and ocular analgesia) due to reduced risk of iatrogenic damage. Further clinical studies are needed.

La pandemia COVID-19 ha puesto de manifiesto un déficit de ventiladores en el sistema sanitario para estas situaciones. Por ello, varios proyectos nacionales e internacionales se han desarrollado en pocas semanas para producir prototipos de ventiladores de fácil y rápida fabricación. Una de las exigencias de la AEMPS para la realización de estudios clínicos con nuevos prototipos pasa por la validación en un modelo animal. Para ello es importante poder utilizar un modelo animal en el que reproducir diferentes situaciones clínicas de forma fácil. En este artículo describimos el uso de la oveja como modelo animal para evaluar un prototipo de ventilador. El animal estuvo anestesiado durante 10 horas en las que el prototipo fue utilizado hasta en 6 escenarios. Este modelo pareció eficaz y es fácilmente reproducible, por lo que es una excelente opción para este tipo de investigación. / The COVID-19 pandemic has revealed a ventilator deficit in the global health system for this scenario. For this reason, several national and international projects have been developed to get done prototypes of ventilators which could be easy and fast to manufacture. One of the requirements of the AEMPS for conducting clinical studies with new prototypes is through the validation of these new prototypes in an animal model. Therefore, it is important to achieve an animal model which allows us to easily reproduce different clinical scenarios. In this article, we describe the use of a sheep as a research model to assess a prototype ventilator. The animal was anesthetized for 10 hours in which the prototype was tested in up to 6 different scenarios. This model is effective and easy to reproduce, making it an excellent choice for this kind of research.

AIM: Obstructive sleep apnea (OSA), characterized by events of hypoxia reoxygenation, is highly prevalent in pregnancy, negatively affecting the gestation process and particularly the fetus. Whether the consequences of OSA on the fetus and offspring are mainly caused by systemic alterations in the mother or by direct effect of intermittent hypoxia in the fetus is unknown. In fact, how apnea-induced hypoxemic swings in OSA are transmitted across the placenta remains to be investigated. The aim of this study was to test the hypothesis, based on a theoretical background on the dampening effect of oxygen transfer in the placenta, that oxygen partial pressure (PO2) swings resulting from obstructive apneas mimicking OSA are mitigated in the fetal circulation. METHODS: To this end, 4 anesthetized ewes close to term pregnancy were subjected to obstructive apneas consisting of 25-s airway obstructions. Real time PO2 was measured in the maternal carotid artery and in the umbilical vein using fast-response fiberoptic oxygen sensors. RESULTS: The amplitude of PO2 swings in the umbilical vein were considerably smaller (3.1±1.0 vs. 21.0±6.1 mmHg (m±SE); p<0.05). Corresponding estimated swings in fetal and maternal oxyhemoglobin saturation tracked PO2 swings. CONCLUSION: This study provides novel insights into fetal oxygenation in a model of gestational OSA, and highlights the importance of further understanding the impact of sleep-disordered-breathing on fetal and offspring development.