Effectiveness of chest compressions skill training in the prone position: comparison of two methods

Introduction

The current pandemic caused by the new coronavirus (COVID-19), has become challenging for the health system.1 Pulmonary complication take patients to require ventilatory support and one of the interventions performed to improve then oxygenation is the prone position.2 In view of the current reality of patients with COVID-19 in a prone position, it is necessary to train cardiopulmonary resuscitation in this position.3 Purpose: To compare the effectiveness of two training methods, video and self-instructional guide, in the ability of chest compressions in prone position.

Methods

This is a randomized clinical trial. The sample consisted of nurses, nursing technicians, physiotherapists and residents of the intensive care and emergency unit of a public hospital. Randomization was performed in blocks of four using the Random @ system. Group 1 (G1) consisted of professionals who watched a validated video while practicing chest compression on a low-fidelity mannequin placed in the prone position. Group 2 (G2) consisted of professionals who practiced compression guided by a previously validated self-instructional guide. The study's outcome was the performance of chest compressions skills assessed before and after interventions, using a previously validated instrument. The study was approved by the Research Ethics Committee (no. 4.016.959).

Results

Ninety-one professionals participated in the study (45 from group 1 and 46 from group 2). It was observed that there was an improvement in hand positioning (G1 pre: 16 professionals correctly and post: 31 (p0.001); G2 pre: 20 correct and post: 20 (p0.781), of body positioning (G1 pre: 32 professionals hit and post: 41; G2 pre: 32 hit and post: 39) and the frequency of compressions G1 pre: 10 professionals hit and post: 19 (p0.017); G2 pre: 13 hit and post: 16 (p0.363)) after the interventions. Statistically, when applying the test within each group, a p-value of 0.0003 was obtained in G1 (video) and 0.512 in G2 (self-instructional guide). Thus, we can infer that only group 1 (video) had a change when we compared the two moments.

Conclusion

The video associated with simulation was more effective than the self-instructional guide and can be used as an attractive and dynamic teaching tool.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

SPARC (secreted protein acidic and rich in cysteine) knockdown protects mice from acute liver injury by reducing vascular endothelial cell damage

Secreted protein, acidic and rich in cysteine (SPARC) is involved in many biological process including liver fibrogenesis, but its role in acute liver damage is unknown. To examine the role of SPARC in acute liver injury, we used SPARC knock-out (SPARC(-/-)) mice. Two models of acute liver damage were used: concanavalin A (Con A) and the agonistic anti-CD95 antibody Jo2. SPARC expression levels were analyzed in liver samples from patients with acute-on-chronic alcoholic hepatitis (AH). SPARC expression is increased on acute-on-chronic AH patients. Knockdown of SPARC decreased hepatic damage in the two models of liver injury. SPARC(-/-) mice showed a marked reduction in Con A-induced necroinflammation. Infiltration by CD4+ T cells, expression of tumor necrosis factor-α and interleukin-6 and apoptosis were attenuated in SPARC(-/-) mice. Sinusoidal endothelial cell monolayer was preserved and was less activated in Con A-treated SPARC(-/-) mice. SPARC knockdown reduced Con A-induced autophagy of cultured human microvascular endothelial cells (HMEC-1). Hepatic transcriptome analysis revealed several gene networks that may have a role in the attenuated liver damaged found in Con A-treated SPARC(-/-) mice. SPARC has a significant role in the development of Con A-induced severe liver injury. These results suggest that SPARC could represent a therapeutic target in acute liver injury.

257 DEVELOPMENT OF HEAT-STRESSED OVA MATURED IN THE PRESENCE OF A PROSTAGLANDIN F2ALPHA RECEPTOR ANTAGONIST

Studies in the literature have shown that cumulus–oocyte complexes produce PGF2α, that ova and cumulus cells have PGF2α receptors, and that PGF2α addition to maturing ova, above what would normally be produced, decreases blastocyst development. Because previous studies have shown elevated systemic and tissue levels of PGF2α as a consequence of heat stress, it was hypothesized that detrimental effects of exposing maturing ova to elevated temperatures may be mediated in part through heat-induced increases in PGF2α. To test this hypothesis, cumulus–oocyte complexes were matured at 38.5 or 41.0°C in the presence of a PGF2α receptor antagonist (AL-8810). Preattachment embryo development of AL-8810-treated ova was compared with development of ova matured in media with or without diluent (DMSO added at the same concentration as AL-8810; diluent and developmental controls, respectively), resulting in 6 total treatment combinations. Data were analyzed as a randomized block design (blocking on oocyte collection date) with fixed effects of maturation temperature, AL-8810, and the respective interaction included in the statistical model. In experimental replicates in which the effects of heat stress decreased blastocyst development greater than 10% (n = 14), a significant maturation temperature × AL-8810 interaction was noted when evaluating blastocyst development (P = 0.05). Specifically, when ova were heat stressed during the first 12 h of in vitro maturation, blastocyst development was reduced in developmental and diluent controls (26.2 v. 18.8 and 24.4 v. 19.9, respectively; SEM = 1.6). In contrast, when ova were matured under the same conditions but in the presence of a PGF2α receptor antagonist, the effects of heat stress to reduce blastocyst development after in vitro fertilization were no longer observed (22.5 v. 22.5; SEM = 1.6). When using abattoir-derived ovaries, it is not uncommon to collect, on occasion, ova that are developmentally challenged (i.e. blastocyst development is less than the 20 to 50% expected). In this experiment, this occurred on 5 occasions. Data from these experimental replicates were analyzed and reported separately because previous efforts had shown that the responsiveness of ova to changes in culture environment differs depending on the level of developmental competence. Relevant to this study, addition of AL-8810 to developmentally challenged ova matured under thermoneutral conditions increased cleavage (60.4 v. 55.4%, respectively; P = 0.06) and blastocyst development (17.7 v. 13.7%, respectively; P = 0.07). In summary, data illustrate that developmentally challenged ova, heat-stressed or otherwise, are susceptible to detrimental effects of PGF2α. The ability to increase blastocyst development approaching or exceeding the values expected for competent ova suggests the usefulness of a PGF2α receptor antagonist during in vitro maturation to improve the efficiency of in vitro production procedures.

Pathology of periportal fibrosis involution in human schistosomiasis

Optical and electron microscopical evidences of focal matrix degradation were frequently seen in liver sections of periportal fibrosis caused by schistosomiasis mansoni in man. The material came from 14 wedge hepatic biopsies taken from patients with chronic advanced hepatosplenic disease and undergoing operations for the relief of portal hypertension. Besides the presence of focal areas of rarefaction, fragmentation and dispersion of collagen fibers, the enlarged portal spaces also showed hyperplasia of elastic tissue and disarray of smooth muscle fibers following destruction of portal vein branches. Eggs were scanty in the tissue sections, and matrix degradation probably represented involuting changes related to the progressive diminution of parasite-related aggression, which occurs spontaneously with age or after cure by chemotherapy. The changes indicative of matrix degradation now described are probably the basic morphological counterpart of periportal fibrosis involution currently being documented by ultrasonography in hepatosplenic patients submitted to curative chemotherapy.

Hepatic connective tissue changes in hepatosplenic schistosomiasis

Destruction of intrahepatic portal vein branches with dispersion of smooth muscle cells into the periportal fibrosis and preservation of arterial and ductal structures were the main characteristic findings seen in 66 surgical liver biopsies from patients with the hepatosplenic form of schistosomiasis. Besides these diagnostic features, the present histologic, immunocytochemical, and ultrastructural study revealed the presence of a complex matrix forming the portal and septal fibrosis in advanced schistosomiasis. There was marked hyperplasia of elastic tissue, presence of several collagen isotypes (I, III, procollagen III, IV, and V), actin, desmin, fibronectin, and laminin in a richly vascularized connective tissue. Signs of multifocal matrix (collagen) degradation were observed both at light and electron microscopic levels, suggesting a predominance of a fibrolytic process, at the time parasite-related lesions had almost disappeared. The latter findings are related to the involution of periportal fibrosis now being observed in patients who have undergone antischistosomal chemotherapy. They exemplify morphologic changes connected with chronic collagen degradation in human schistosomiasis that are similar to those first seen in experimental material. Evidence of either persistent or active chronic hepatitis was seen in several cases but its etiology could not be determined.