Evaluation of nasogastric tube fixation methods: adhesion, displacement and skin integrity.

OBJECTIVE: to evaluate three methods of nasogastric tube fixation in terms of adhesion, displacement and skin integrity. METHOD: ex vivo study, with a sample of 30 experimental noses (10 for each type of fixation), developed with porcine skin, based on the average measurements of the human nose, in which 14-gauge polyvinyl chloride probes were inserted and 2 methods of fixation with adhesive tape (Fixation A and B) and one with an industrial device (Fixation C) were used. Each group was exposed to traction of 50, 100 and 500g sequentially over 12 and 24 hours, testing: adhesion capacity, probe displacement and skin integrity. The Chi-square test of independence was calculated for nominal variables and Student's t-tests and analysis of variance (p< 0.05) for rational variables. RESULTS: fixation B showed lower adhesion capacity (p <0.001) when compared to the other two fixations. A mean displacement of 52.17 mm was observed in the probes fixed by methods A and B and a greater occurrence of lesions associated with fixations A and C (p = 0.001). CONCLUSION: the results show complications related to the fixations: lack of adhesion, displacement of the probe and skin lesions, drawing attention to the complexity of the procedure.

Evaluation of nasogastric tube fixation methods: adhesion, displacement and skin integrity / Evaluación de los métodos de fijación de sonda nasogástrica: adherencia, desplazamiento e integridad de la piel / Avaliação dos métodos de fixação de sonda nasogástrica: adesão, deslocamento e integridade da pele

Objective: to evaluate three methods of nasogastric tube fixation in terms of adhesion, displacement and skin integrity. Method: ex vivo study, with a sample of 30 experimental noses (10 for each type of fixation), developed with porcine skin, based on the average measurements of the human nose, in which 14-gauge polyvinyl chloride probes were inserted and 2 methods of fixation with adhesive tape (Fixation A and B) and one with an industrial device (Fixation C) were used. Each group was exposed to traction of 50, 100 and 500g sequentially over 12 and 24 hours, testing: adhesion capacity, probe displacement and skin integrity. The Chi-square test of independence was calculated for nominal variables and Student's t-tests and analysis of variance (p< 0.05) for rational variables. Results: fixation B showed lower adhesion capacity (p <0.001) when compared to the other two fixations. A mean displacement of 52.17 mm was observed in the probes fixed by methods A and B and a greater occurrence of lesions associated with fixations A and C (p = 0.001). Conclusion: the results show complications related to the fixations: lack of adhesion, displacement of the probe and skin lesions, drawing attention to the complexity of the procedure.

Objetivo: evaluar tres métodos de fijación de sonda nasogástrica en cuanto a adherencia, desplazamiento e integridad de la piel. Método: estudio ex vivo , con una muestra de 30 narices experimentales (10 para cada tipo de fijación), desarrolladas con piel porcina, a partir de las medidas medias de la nariz humana, en las cuales se introdujeron sondas de poli cloruro de vinilo calibre 14 y se utilizaron 2 métodos de fijación con esparadrapo (Fijador A y B), y uno con dispositivo industrial (Fijador C). Cada grupo fue expuesto a tracción de 50, 100 y 500g secuencialmente en el período de 12 y 24 horas, testeándose: capacidad de adherencia, desplazamiento de la sonda e integridad de la piel. Se calculó el test Chi-cuadrado de independencia para variables nominales y pruebas t-Student y Análisis de varianza (p< 0,05) para las racionales. Resultados: el fijador B presentó capacidad inferior de adherencia (p <0,001) cuando comparado a los otros dos fijadores. Se observó un desplazamiento medio de 52,17 mm en las sondas fijadas por los métodos A y B y una mayor ocurrencia de lesiones asociadas a los fijadores A y C (p = 0,001). Conclusión: los resultados atestiguan complicaciones relacionadas a los fijadores: falta de adherencia, desplazamiento de la sonda y lesiones de piel, llamando atención para la complejidad del procedimiento.

Objetivo: avaliar três métodos de fixação de sonda nasogástrica quanto à adesão, deslocamento e integridade da pele. Método: estudo ex vivo , com uma amostra de 30 narizes experimentais (10 para cada tipo de fixação), desenvolvidos com pele suína, a partir das medidas médias do nariz humano, nos quais foram introduzidas sondas de poli cloreto de vinila calibre 14 e utilizados dois métodos de fixação com esparadrapo (Fixador A e B), e, um com dispositivo industrial (Fixador C). Cada grupo foi exposto à tração de 50, 100 e 500g sequencialmente no período de 12 e 24 horas, testando-se: capacidade de adesão, deslocamento da sonda e integridade da pele. Calculou-se o teste Qui-quadrado de independência para variáveis nominais e testes t-Student e Análise de variância (p< 0,05) para as racionais. Resultados: o fixador B apresentou capacidade inferior de adesão (p <0,001) quando comparado aos outros dois fixadores. Observou-se um deslocamento médio de 52,17 mm nas sondas fixadas pelos métodos A e B e uma maior ocorrência de lesões associadas aos fixadores A e C (p = 0,001). Conclusão: os resultados atestam para complicações relacionadas aos fixadores: falta de adesão, deslocamento da sonda e lesões de pele chamando atenção para complexidade do procedimento.

Non-linear dynamics of chromosome condensation induced by colcemid

This study investigated the dynamical process of chromosome condensation after colcemid treatment. Two pairs of human chromosomes, #2 and #3, were highlighted for the accurate identification by fluorescence in situ hybridization (FISH). A computerized image analysis system was used to measure the lengths of the two pairs of chromosomes averaged over 50 metaphases of different cultures with colcemid (0.5 µg/mL) added either at 3 or 48 h of a total 72 h culture period. For determining whether the process of chromosome condensation was chaotic or random, the algorithm of Detrended Fluctuation Analysis (DFA) was used. In order to evaluate the power of the method, the data were shuffled and DFA was performed again. It was found that colcemid prolonged treatment induced a significantly greater chromosome condensation (p<0.05), and the dynamics of this process was determined by the DFA and showed to be chaotic, with scaling exponents with range values 0.5< α<1.0. When the data were shuffled, the scaling exponent αreduced around to 0.5, which was characteristic of random events. These findings reinforced the idea that colcemid could interfere in some manner with the structure of chromosomes and the dynamics of chromosome condensation was non-linear.

Potentiation of spontaneous and evoked cortical electrical activity after spreading depression: in vivo analysis in well-nourished and malnourished rats.

Cortical spreading depression (CSD) is influenced by brain excitability and is related to neurological diseases, such as epilepsy. In vitro evidence indicates that neuronal electrical activity is potentiated after CSD. Malnutrition can cause electrophysiological changes in the brain, both in animals and in humans. Here, we investigated in vivo whether CSD potentiates the amplitude of electrocorticogram (ECoG) and of transcallosal evoked responses in adult well-nourished (W), early-malnourished (M), and food-restricted rats. ECoG amplitudes were compared before and after CSD, at two parietal regions (designated the anterior and posterior regions). In the anterior region, post-CSD amplitudes of the ECoG waves were 13-23% higher (P < 0.05) than the pre-CSD values in all groups. In the posterior region, amplitudes increased 22% in the M group only (P < 0.05). In a fourth CSD-free group, ECoG amplitude did not change during the four recording hours. Transcallosal electrically evoked cortical responses also increased 21.5 ± 9.6% and 41.8 ± 28.5%, after CSD, in the W and M conditions, respectively, as compared to pre-CSD values. The data support the hypothesis of an in vivo CSD potentiation on cortical excitability as recorded by spontaneous and evoked electrical activity and modulation by nutritional status.