Remimazolam vs. propofol for general anaesthesia in elderly patients: a meta-analysis with trial sequential analysis.

BACKGROUND: Elderly patients comprise an increasing proportion of patients undergoing surgery, and they require special attention due to age-related physiological changes. Propofol is the traditional agent for anaesthesia, and recently, remimazolam, a novel ultra-short-acting benzodiazepine, has emerged as an alternative to propofol in general anaesthesia. OBJECTIVES: We aim to compare remimazolam vs . propofol for general anaesthesia in elderly patients regarding hypotension, induction characteristics, haemodynamics and recovery outcomes. DESIGN: Meta-analysis with sensitivity and trial sequential analyses (TSA) to assess inconsistencies. Risk ratios and mean differences with 95% confidence intervals (95% CIs) were computed using a random effects model. Subgroups and meta-regression according to anaesthesia methods were also performed. DATA SOURCES: We systematically searched MEDLINE, Embase and Cochrane for randomised controlled trials (RCTs) up to January 1, 2024. ELIGIBILITY CRITERIA: Patients at least 60 years old, comparing remimazolam vs . propofol for general anaesthesia. RESULTS: Eleven RCTs (947 patients) were included. Compared with propofol, remimazolam was associated with lower postinduction and intra-operative hypotension (RR 0.41, 95% CI 0.27 to 0.62, P  < 0.001) and incidence of bradycardia (risk ratio 0.58, 95% CI 0.34 to 0.98, P  = 0.04), with a higher heart rate ( P  = 0.01). The incidence of injection pain was lower ( P  < 0.001), but remimazolam was associated with a longer time to loss of consciousness ( P  < 0.001) and a higher bispectral index at loss of consciousness ( P  = 0.04). No differences were found for mean arterial pressure, emergence time, extubation time and incidence of emergence agitation. The TSA was consistent and achieved the required information size for hypotension. CONCLUSIONS: Remimazolam significantly reduced the risk of hypotension, bradycardia and injection pain, despite an increase in the time to loss of consciousness. Remimazolam appears to be an effective and well tolerated alternative to propofol in elderly patients undergoing general anaesthesia.

Comparison of intranasal dexmedetomidine versus oral midazolam for premedication in pediatric patients: an updated meta-analysis with trial-sequential analysis.

BACKGROUND: Midazolam is routinely used as preanesthetic medication in pediatric patients. Recently, dexmedetomidine has emerged as an alternative as a premedicant. We aimed to add more evidence about the efficacy and safety of two common routes of administration for pediatric premedication: oral midazolam versus intranasal dexmedetomidine. METHODS: We systematically searched Randomized Controlled Trials (RCTs) involving patients ≤ 18 years old undergoing preanesthetic medication and comparing intranasal dexmedetomidine with oral midazolam. Risk Ratio (RR) and Mean Difference (MD) with 95% Confidence Intervals (95% CI) were computed using a random effects model. Trial-sequential analyses were performed to assess inconsistency. RESULTS: Sixteen RCTs (1,239 patients) were included. Mean age was 5.5 years old, and most procedures were elective. There was no difference in satisfactory induction or mask acceptance (RR = 1.15, 95% CI 0.97-1.37; p = 0.11). There was a higher incidence of satisfactory separation from parents in the dexmedetomidine group (RR = 1.40; 95% CI 1.13-1.74; p = 0.002). Dexmedetomidine was also associated with a reduction in the incidence of emergence agitation (RR = 0.35; 95% CI 0.14-0.88; p = 0.02). Heart rate and mean arterial pressure were marginally lower in the dexmedetomidine group but without clinical repercussions. CONCLUSION: Compared with oral midazolam, intranasal dexmedetomidine demonstrated better separation from parents and lower incidence of emergence agitation in pediatric premedication, without a difference in satisfactory induction. Intranasal dexmedetomidine may be a safe and effective alternative to oral midazolam for premedication in pediatric patients.

Metemoglobinemia: do diagnóstico ao tratamento / Metahemoglobinemia: del diagnóstico al tratamiento / Methemoglobinemia: from diagnosis to treatment

JUSTIFICATIVAS E OBJETIVOS: A metemoglobina é a forma oxidada da hemoglobina, que além de não se ligar ao oxigênio, aumenta a afinidade deste pela porção parcialmente oxidada da hemoglobina. A concentração aumentada da metemoglobina no sangue decorre de alterações congênitas e de exposição a agentes químicos diversos, resultando em quadro com múltiplos diagnósticos diferenciais, que se não tratado pode levar ao óbito. Foi feita revisão sobre o assunto, dando ênfase às informações relevantes para o manuseio clínico dos pacientes. CONTEÚDO: Quando a concentração sangüínea de metemoglobina está acima de 1,5 por cento surge a cianose, característica principal da doença. Os pacientes apresentam sangue arterial de coloração marrom-escuro com a PaO2 normal. O diagnóstico deve ser suspeitado em pacientes que apresentem cianose e baixa leitura de saturação ao oxímetro de pulso (SpO2), sem que haja comprometimento cardiopulmonar significativo. A co-oximetria é o método padrão-ouro e define o diagnóstico. No tratamento dos pacientes devem ser considerados o caráter agudo ou crônico da síndrome (etiologia) e a gravidade dos sintomas. A concentração sangüínea de metemoglobina é importante, sobretudo nos casos agudos. O tratamento básico consiste na remoção do agente causador, administração de oxigênio e observação. Casos graves devem ser tratados com azul-de-metileno, antídoto específico, porém ineficaz em algumas situações. CONCLUSÃO: A metemoglobinemia é condição potencialmente grave, cujo diagnóstico depende do alto grau de suspeição. Em geral, os anestesiologistas, no período perioperatório, são os primeiros a detectarem o problema e devem liderar a condução do tratamento.

BACKGROUND AND OBJECTIVES: Methemoglobin is the oxidized form of hemoglobin, which does not bind oxygen and increases the affinity of oxygen for the partially oxidized portion of hemoglobin. Increased levels of methemoglobin in the blood are secondary to congenital changes and exposure to several chemical agents, resulting in a disorder with several differential diagnoses, which it can lead to death if it is not treated. The objective of this report was to review this subject, emphasizing relevant information for the clinical management of patients with methemoglobinemia. CONTENTS: When the concentration of methemoglobin in the blood is above 1.5 percent, the patient develops cyanosis, the main characteristic of this disorder. The color of the arterial blood changes to dark brown with normal PaO2. One should suspect the diagnosis in patients with cyanosis and low saturation (SpO2) without significant cardiopulmonary dysfunction. Co-oximetry is the gold standard and defines the diagnosis. Treatment should be based on whether the syndrome is acute or chronic (etiology) and on the severity of symptoms. Blood levels of methemoglobin are important, especially in acute cases. Basic treatment includes removal of the agent responsible for the disorder, administration of oxygen, and observation. Severe cases should be treated with the specific antidote, methylene blue, which is not effective in some situations. CONCLUSIONS: Methemoglobinemia is a potentially severe disorder, whose diagnosis depends on a high degree of suspicion. In general, anesthesiologists are the first to detect the problem in the preoperative period and should lead the treatment.

JUSTIFICATIVAS Y OBJETIVOS: La metahemoglobina es la forma oxidada de la hemoglobina, que, además de no vincularse con el oxígeno, aumenta su afinidad por la porción parcialmente oxidada de la hemoglobina. La concentración aumentada de la metahemoglobina en la sangre, proviene de las alteraciones congénitas y de la exposición a agentes químicos diversos, trayendo como resultado, un cuadro con múltiples diagnósticos diferenciales, que si no se trata, puede conllevar al deceso. Se hizo una revisión sobre el asunto, dándole énfasis a las informaciones relevantes para el manejo clínico de los pacientes. CONTENIDO: Cuando la concentración sanguínea de metahemoglobina está por encima de 1,5 por ciento surge la cianosis, característica principal de la enfermedad. Los pacientes presentan sangre arterial de coloración marrón oscuro con la PaO2 normal. El diagnóstico debe suponerse en pacientes que presenten cianosis y una baja lectura de saturación al oxímetro de pulso (SpO2), sin que exista un comprometimiento cardiopulmonar significativo. La co-oximetría es el método estándar de oro y define el diagnóstico. En el tratamiento de los pacientes, deben ser considerados el carácter agudo o crónico del síndrome (etiología) y la gravedad de los síntomas. La concentración sanguínea de metahemoglobina es importante principalmente en los casos agudos. El tratamiento básico consiste en la retirada del agente causador, administración de oxígeno y observación. Casos graves deben ser tratados con azul de metileno, antídoto específico, sin embargo ineficaz en algunas situaciones. CONCLUSIÓN: La Metahemoglobinemia es una condición potencialmente grave, cuyo diagnóstico depende del alto grado de sospecha. En general, los anestesiólogos, en el período perioperatorio, son los primeiros que detectan el problema y deben liderar el tratamiento.