Oxidative stress evaluation of ischemia and reperfusion in kidneys under various degrees of hypothermia in rats

PURPOSE: To design an animal model of ischemia-reperfusion (I/R) in kidneys and evaluate the role that predetermined ranges of local hypothermia plays on markers of stress-oxydative as well as on histologic sections. METHODS: Twenty eight male rats Wistar, under general anesthesia, undergone right nephrectomy (G0, control group) followed by left kidney ischemia during 40 min. Four temperatures groups were designed, with seven animals randomized for each group: normothermic (G1, ±37oC), mild hypothermia (G2, 26oC), moderate hypothermia (G3, 15oC) and deep hypothermia (G4, 4oC). Left kidney temperature was assessed with an intraparenchymal probe. Left nephrectomy was performed after 240 min of reperfusion. After I/R a blood sample was obtained for f2-IP. Half of each kidney was sent to pathological evaluation and half to analyze CAT, SOD, TBARS, NO3, NO2. RESULTS: Histopathology showed that all kidneys under I/R were significantly more injured than the G0 (p<0.001). TBARS had increased levels in all I/R groups compared with the G0 (p<0.001). CAT had a significant difference (p<0.03) between G1 and G4. Finally, no difference was found on SOD, NO3, NO2 nor on f2-IP. CONCLUSION: This model of I/R was efficient to produce oxidative-stress in the kidney, showing that 4ºC offered significant decrease in free radicals production, although tissue protection was not observed

Cardiorespiratory Dynamics of Sedated Pigs Submitted to Diff erent Inspired Oxygen Fractions under Controlled Mechanical Ventilation*

ABSTRACT Background: Individuals submitted to situations of deep sedation have a marked decrease in their ventilatory capacity. The provision of adequate ventilation and oxygenation in critically ill patients submitted to sedation in intensive therapy has been the subject of special care. In such cases, exposure to low inspired oxygen fractions (F I O 2 ) is a factor that can infl uence alveolar perfusion and respiratory performance. The aim of this study is to evaluate the effects of three inspired oxygen fractions (80%, 60% or 40%) on the cardiorespiratory dynamics of pigs submitted to mechanical ventilation by intermittent positive pressure in deep sedation with propofol-remifentanil. Material, Methods &amp; Results: Twenty crossbred pigs weighing between 17 and 25 kg and aged between 60 and 90 days were used. Each animal was submitted to deep sedation for 2h in randomly assigned F I O 2 (80%, 60% or 40%). Scores such as heart and respiratory rate, blood pressure, respirometry (PaO 2 , P(A-a)O 2 , P IP , V min ), physiological dead space, pulmonary shunt and blood gas analysis (pH, PaO 2 , PaCO 2 , HCO 3 ) were observed, evaluated and compared. Patients were evaluated after sedation was induced with propofol (12 mg.k

Experimental model of the formation of pelvic adhesions by videolaparoscopic in female rabbits Modelo experimental de formação de aderências pélvicas por videolaparoscopia em coelhas

PURPOSE: To verify the frequency of postsurgical pelvic adhesion formation in an experimental animal model using videolaparoscopy. METHODS: Experimental study in a sample of 11 non-pregnant female rabbits, aged 5 to 7 months. After general anesthesia, access to the abdominal cavity was performed by an open puncture technique, with 10mm optics, placing two other 5 mm trochars under direct visualization, in the iliac fossae. Then a fragment of peritoneum was resected, followed by electrocauterization. In 21 days, the videolaparoscopy was repeated, and adhesion formation and score was looked at, with biopsies at the surgical site. RESULTS: 54 % of adhesion formation was observed, and the median score of adhesions was 6 (minimum of 3 and maximum of 10), all of them found in the bladder and the anterior abdominal wall. CONCLUSION: The method used presents a high frequency of intra-abdominal adhesion formation.<br>OBJETIVO: Verificar a freqüência da formação de aderências pélvicas pós-cirúrgicas, em um modelo experimental animal, por videolaparoscopia. MÉTODOS: Estudo experimental, em uma amostra de 11 coelhas, não prenhas, com idade entre cinco e sete meses. Após anestesia geral, o acesso da cavidade abdominal foi efetuado por técnica de punção aberta, com óptica de 10 mm, colocando-se outros dois trocateres de 5 mm, sob visão direta, nas fossas ilíacas. Realizou-se, então, ressecção de fragmento de peritônio, seguida de cauterização com eletrocautério. Em 21 dias, foi repetida a videolaparoscopia, verificando-se a formação e escore de aderências e realizando-se biópsias do local da cirurgia. RESULTADOS: Observou-se 54,5% de formação de aderências, sendo o escore total mediano de aderências seis (mínimo de três e máximo de 10), todas encontradas na bexiga e na parede abdominal anterior. CONCLUSÃO: O procedimento utilizado apresentou alta freqüência de formação de aderências intra-abdominais

Anesthetic protocol for videolaparoscopic surgery in rabbits Protocolo anestésico para cirurgia videolaparoscópica em coelhos

PURPOSE: To describe the anesthetic protocol and the intubation technique without visualizing the trachea in rabbits, in order to enable the videolaparoscopic surgical procedure. METHODS: The experiment was performed on 33 female rabbits (Oryctolagus cuniculus), aged from 5 to 7 months. It consisted of general anesthesia and endotracheal intubation by manual palpation of the trachea of the rabbits, without using the laryngoscope, orally, for later videolaparoscopic surgical access to the abdominal cavity. RESULTS: The mean values and standard deviation of vital parameters of the animals were 223.8±15.61 beats per minute for heart rate; 35±9 movements per minute for respiratory rate; 96.94±0.99% of oxymetry and 42.82±4.02 mmHg for capnometry; 16.7±4.3 minutes for pneumoperitoneum (duration of surgery) and 1 hour and 14±8.52 minutes for time of observation (from induction to recovery from anesthesia). All animals were intubated in at most three attempts. No animals were lost after the introduction of this anesthetic technique. CONCLUSION: This protocol proved adequate, safe and easy to perform, on rabbits submitted to videolaparoscopic surgery.<br>OBJETIVO: Descrever o protocolo anestésico e a técnica de intubação sem visualização da traqueia em coelhos, para viabilização de procedimento cirúrgico videolaparoscópico. MÉTODOS: O experimento foi realizado em 33 coelhas (Oryctolagus cuniculus), com idade entre 5 e 7 meses. Consistiu de anestesia geral e intubação endotraqueal por meio de palpação manual da traquéia das coelhas, sem o uso de laringoscópio, pela via oral, para posterior acesso cirúrgico videolaparoscópico da cavidade abdominal. RESULTADOS: Os valores médios e desvio padrão dos parâmetros vitais dos animais foram de 223,8±15,61 batimentos por minuto para freqüência cardíaca; 35±9 movimentos por minuto para frequência respiratória; 96,94±0,99% de oximetria e 42,82±4,02 mmHg para capnometria; 16,7±4,3 minutos para o pneumoperitônio (tempo de cirurgia) e 1 hora e 14±8,52 minutos para o tempo de observação (desde a indução até a recuperação anestésica). Todos os animais foram intubados em, no máximo, três tentativas. Não houve perda de animais após a introdução dessa técnica anestésica. CONCLUSÃO: Este protocolo mostrou-se adequado, seguro e de fácil realização, para a aplicação em coelhos submetidos à cirurgia videolaparoscópica