The analgesic effect of nitroglycerin added to lidocaine on quality of intravenous regional anesthesia in patients undergoing elective forearm and hand surgery

PURPOSE: To evaluate the effect of nitroglycerine (NTG) on sensory and motor block onset and recovery time as well as the quality of tourniquet pain relief, when added to lidocaine (LID) for intravenous regional anesthesia in elective forearm and hand surgery. METHODS: A randomized double-blinded clinical trial was performed on 40 patients that were randomly allocated into two groups received lidocaine 3 mg/kg with NTG 200 µg or received only lidocaine 3 mg/kg as the control. RESULTS: There was no difference between the two study groups in hemodynamic parameters before tourniquet inflation, at any time after inflation and after its deflation. There was no difference in the mean of pain score over time between the two groups. The onset time of sensory and motor blockades was shorter in the group received both LID and NTG. The mean recovery time of sensory blockade was longer in the former group. The frequency of opioid injections was significantly lower in those who administered LID and NTG. CONCLUSION: The adjuvant drug of NTG when added to LID is effective in improving the overall quality of anesthesia, shortening onset time of both sensory and motor blockades, and stabling homodynamic parameters in hand and forearm surgery.(AU)

The effects of local nitroglycerin on the surgical delay procedure in prefabricated flaps by vascular implant in rats / Efeitos da nitroglicerina tópica na autonomização de retalhos pré-fabricados por implante vascular em ratos

PURPOSE: To evaluate the effect of local nitroglycerin on the viable area of a prefabricated flap for vascular implant in rats, and to investigate the surgical delay procedure. METHODS: A femoral pedicle was implanted under the skin of the abdominal wall in forty Wistar rats. The animals were divided into four groups of ten: group 1 - without surgical delay procedure and local nitroglycerin; group 2 - with surgical delay procedure, but without local nitroglycerin; group 3 - without surgical delay procedure, but with local nitroglycerin; and group 4 - with simultaneous surgical delay procedure and local nitroglycerin. The percentages of the viable areas, in relation to the total flap, were calculated using AutoCAD R 14. RESULTS: The mean percentage value of the viable area was 8.9% in the group 1. 49.4% in the group 2; 8.4% in the group 3 and 1.1% in the group 4. There was significant difference between groups 1 and 2 (p=0.005), 1 and 4 (p=0.024), 2 and 3 (p=0.003), 2 and 4 (p=0.001). These results support the hypothesis that the closure of the arterial venous channels is responsible for the phenomenon of surgical delay procedure. CONCLUSION: Local nitroglycerin did not cause an increase in the prefabricated viable flap area by vascular implantation and decreased the viable flap area that underwent delay procedures.(AU)

OBJETIVO: Avaliar o efeito da nitroglicerina tópica sobre a área viável de um modelo de retalho pré-fabricado por implante vascular em ratos e analisar o mecanismo de autonomização cirúrgica aplicada a retalhos pré-fabricados. MÉTODOS: Foram utilizados 40 ratos Wistar. No primeiro tempo cirúrgico - 20 ratos foram submetidos a implante do pedículo femoral na região subdérmica da parede abdominal, e 20 submetidos à autonomização cirúrgica de retalho cutâneo de parede abdominal e, simultaneamente, implante do pedículo femoral na região subdérmica deste retalho. No segundo tempo - após três semanas e em todos os animais, era elevado um retalho cutâneo ilhado, pediculado unicamente nos vasos implantados e divididos em quatro grupos de dez animais: grupo 1, com retalhos submetidos unicamente a implante do pedículo femoral na região subdérmica da parede abdominal; grupo 2, com retalhos submetidos à autonomização cirúrgica e implante do pedículo femoral na região subdérmica deste retalho; grupo 3, com retalhos submetidos unicamente a implante do pedículo femoral na região subdérmica da parede abdominal tratados com nitroglicerina tópica; grupo 4, com retalhos submetidos à autonomização cirúrgica e implante do pedículo femoral na região subdérmica deste retalho tratados com nitroglicerina tópica. O percentual de área viável, em relação à área total do retalho, foi calculado sete dias após o segundo tempo cirúrgico. RESULTADOS: O valor médio de área viável alcançou 8,9% no grupo 1; 49,4% no grupo 2; 8,4% no grupo 3; e 1,1% no grupo 4. Houve diferença significante entre os grupos 1 e 2 (p=0,005); 1 e 4 (p=0,024); 2 e 3 (p=0,003) e 2 e 4 (p=0,001). Os resultados fortaleceram a hipótese de que o fechamento dos canais arteriovenosos é o principal mecanismo responsável pelo aumento da área viável observada em retalhos submetidos à autonomização cirúrgica.CONCLUSÃO: A nitroglicerina tópica não induziu ao aumento da área viável dos retalhos pré-fabricados por implante vascular e diminuiu a área viável dos retalhos submetidos à autonomização.(AU)