Simple method for determining the size of the ProSeal laryngeal mask airway in children: a prospective observational study / Método simples para determinar o tamanho da máscara laríngea ProSeal em crianças: um estudo observacional, prospectivo

Abstract Background and objectives: The size of the ProSeal laryngeal mask airway in children is determined by the patient's weight. However, in some instances, an alternative method may be required. This study aimed to compare sizing by the auricle with conventional ProSeal laryngeal mask airway sizing by weight in children. Methods: After approval by the institutional ethics board and written informed consent from parents, 197 children with American Society of Anesthesiologists physical status I-II who were scheduled for a routine genitourinary operation were included in the study. The correct ProSeal laryngeal mask airway size was determined according to the size of the auricle in children. The results were compared with the standard weight-based method recommended by the manufacturer's guidelines. The patients were classified into different groups depending on the ProSeal laryngeal mask airway sizes as determined by both methods. Agreement between both techniques was evaluated with κ coefficient statistics. Results: Insertion and adequate ventilation were achieved in 185 patients at the first attempt, and 12 patients required a second attempt. Three patients had to be intubated. Agreement between the two methods of size selection of the ProSeal laryngeal mask airway was moderate using κ statistics. Conclusions: Choosing the size of the ProSeal laryngeal mask airway in children according to the auricle of the child is valid and practical. In particular, this is an alternative method in situations where the patient's weight is unknown, such as in emergency situations.

Resumo Justificativa e objetivos: O tamanho da máscara laríngea ProSeal (MLPS) em crianças é determinado com base no peso do paciente. No entanto, em alguns casos, pode ser necessário um método opcional. Este estudo teve como objetivo comparar o tamanho da MLPS convencional pela orelha e pelo peso em crianças. Métodos: Após aprovação do Comitê de Ética institucional e receber o consentimento informado assinado pelos pais, 197 crianças com estado físico ASA I-II (de acordo com a classificação da Sociedade Americana de Anestesiologistas), programadas para uma operação geniturinária de rotina, foram incluídas no estudo. O tamanho correto da MLPS foi determinado de acordo com o tamanho da orelha em crianças. Os resultados foram comparados com os do método padrão, baseado no peso, recomendado pelas diretrizes do fabricante. Os pacientes foram classificados em diferentes grupos, a depender dos tamanhos das MLPS, conforme determinado por ambos os métodos. A concordância entre as duas técnicas foi avaliada com as estatísticas do coeficiente kappa (k). Resultados: Inserção e ventilação adequada foram obtidas em 185 pacientes na primeira tentativa e 12 pacientes precisaram de uma segunda tentativa. Três pacientes precisaram ser intubados. A concordância entre os dois métodos de seleção do tamanho da MLPS foi moderada com a estatística κ. Conclusões: A escolha do tamanho da MLPS em crianças de acordo com a orelha da criança é válida e prática. Em particular, é um método opcional em situações nas quais o peso do paciente é desconhecido, como em situações de emergência.

Dexmedetomidine as an adjunct to anesthetic induction to attenuate hemodynamic response to endotracheal intubation in patients undergoing fast-track CABG.

During induction of general anesthesia hypertension and tachycardia caused by tracheal intubation may lead to cardiac ischemia and arrhythmias. In this prospective, randomized study, dexmedetomidine has been used to attenuate the hemodynamic response to endotracheal intubation with low dose fentanyl and etomidate in patients undergoing myocardial revascularization receiving beta blocker treatment. Thirty patients undergoing myocardial revascularization received in a double blind manner, either a saline placebo or a dexmedetomidine infusion (1 µg/kg) before the anesthesia induction. Heart rate (HR) and blood pressure (BP) were monitored at baseline, after placebo or dexmedetomidine infusion, after induction of general anesthesia, one, three and five minutes after endotracheal intubation. In the dexmedetomidine (DEX) group systolic (SAP), diastolic (DAP) and mean arterial pressures (MAP) were lower at all times in comparison to baseline values; in the placebo (PLA) group SAP, DAP and MAP decreased after the induction of general anesthesia and five minutes after the intubation compared to baseline values. This decrease was not significantly different between the groups. After the induction of general anesthesia, the drop in HR was higher in DEX group compared to PLA group. One minute after endotracheal intubation, HR significantly increased in PLA group while, it decreased in the DEX group. The incidence of tachycardia, hypotension and bradycardia was not different between the groups. The incidence of hypertension requiring treatment was significantly greater in the PLA group. It is concluded that dexmedetomidine can safely be used to attenuate the hemodynamic response to endotracheal intubation in patients undergoing myocardial revascularization receiving beta blockers.