Effect of two different doses of dexmedetomidine on the incidence of emergence agitation after strabismus surgery: a randomized clinical trial

Background and objective: Emergence agitation is a postoperative negative behavior that affects mainly children. We studied the effect of two different doses of dexmedetomidine on the incidence and degree of EA in children undergoing strabismus surgery. Methods: 90 patients were allocated into three equal groups; patients received 0.5 μg.kg−1 of dexmedetomidine in high Dex group, 0.25 μg.kg−1 of dexmedetomidine in low Dex group, or normal saline in the placebo group. All drugs were received with the closure of the conjunctiva before the end of the surgery. Pediatric Anesthesia Emergence Delirium (PAED) scale was used to evaluate the agitation, and Face, Legs, Activity, Cry, Consolability (FLACC) scale was used for pain assessment. Adverse effects of dexmedetomidine and recovery times were recorded. Results: The incidence of agitation was significantly lower in high Dex group compared to other groups and it was significantly lower in low Dex group compared to placebo group. The median (range) of FLACC score was significantly lower in both Dex groups compared to placebo group. Recovery times; time from removal of laryngeal mask to eye opening and time stay in post anesthesia care unit was significantly longer in high Dex group compared to other groups. No significant bradycardia or hypotension was recorded. Recovery time was significantly longer in high Dex group compared to the other two groups. Conclusion: Dexmedetomidine (0.5 μg.kg−1) before emergence from general anesthesia resulted in a reduction in the incidence of emergence agitation compared to a dexmedetomidine (0.25 μg.kg−1) but on the expense of recovery times without adverse effects. Resumo: Justificativa e objetivo: A agitação ao despertar é um comportamento pós-operatório negativo que afeta principalmente as crianças. Avaliamos o efeito de duas doses diferentes de dexmedetomidina na incidência e grau de agitação ao despertar em crianças submetidas à correção de estrabismo. Métodos: Noventa pacientes foram alocados em três grupos iguais: receberam 0,5 μg.kg−1 de dexmedetomidina (grupo Dex-alta), 0,25 μg.kg−1 de dexmedetomidina (grupo Dex-baxia) ou solução salina normal (grupo placebo). Todos os medicamentos foram administrados com o fechamento da conjuntiva antes do fim da cirurgia. A escala pediátrica de delírio ao despertar da anestesia (PAED – Pediatric Anesthesia Emergence Delirium) foi usada para avaliar a agitação e a escala dos padrões de face, pernas, atividade, choro e consolabilidade (FLACC – Face, Legs, Activity, Cry, Consolability) foi usada para avaliar a dor. Os efeitos adversos de dexmedetomidina e os tempos de recuperação foram registrados. Resultados: A incidência de agitação foi significativamente menor no grupo Dex-alta em comparação com os outros grupos, foi significativamente menor no grupo Dex-baxia em comparação com o grupo placebo. A mediana (variação) do escore FLACC foi significativamente menor em ambos os grupos Dex em comparação com o grupo placebo. O tempo de recuperação, o tempo transcorrido desde a remoção da máscara laríngea até a abertura dos olhos e o tempo de permanência na sala de recuperação pós-anestesia foram significativamente maiores no grupo Dex-alta em comparação com os outros grupos. Não houve registro de bradicardia ou hipotensão significativa. O tempo de recuperação foi significativamente maior no grupo Dex-alta em comparação com os outros dois grupos. Conclusão: Dexmedetomidina (0,5 μg.kg−1) antes do despertar da anestesia geral resultou em uma redução da incidência de agitação ao despertar em comparação com dexmedetomidina (0,25 μg.kg−1), mas em detrimento dos tempos de recuperação sem efeitos adversos. Keywords: Children, Dexmedetomidine, Emergence agitation, Sevoflurane, Strabismus surgery, Palavras-chave: Crianças, Dexmedetomidina, Agitação ao despertar, Sevoflurano, Correção de estrabism

Effect of slow versus rapid rewarming on jugular bulb oxygen saturation in adult patients undergoing open heart surgery

Background: A debate has appeared in the recent literature about the optimum rewarming strategy (slow vs. rapid) for the best brain function. This study was designed to compare the effect of slow versus rapid rewarming on jugular bulb oxygen saturation (SjO 2 ) in adult patients undergoing open heart surgery. Materials and Methods: A total of 80 patients undergoing valve and adult congenital heart surgery were randomly allocated equally to rapid rewarming group 0.5 (0.136)°C/min and slow rewarming group 0.219 (0.055)°C/min in jugular bulb sampling was taken before, during and after surgery. Surgery was done at cardiopulmonary bypass (CPB) temperature of 28-30°C and rewarming was performed at the end of the surgical procedure. Results: CPB time, rewarming period were significantly longer in the slow rewarming group. Significant difference was observed in the number of the desaturated patients (SjO 2 ≤ 50%) between the two groups; 14 (35%) in rapid rewarming versus 6 (15%) in the slow rewarming group; P = 0.035 by Fisher′s exact test. Conclusions: Slow rewarming could reduce the incidence of SjO 2 desaturation during rewarming in adult patients undergoing open heart surgery