The effects of positive end-expiratory pressure (PEEP) application on optic nerve sheath diameter in patients undergoing laparoscopic cholecystectomy: a randomized trial

Abstract Background: Positive end-expiratory pressure (PEEP) can overcome respiratory changes that occur during pneumoperitoneum application in laparoscopic procedures, but it can also increase intracranial pressure. We investigated PEEP vs. no PEEP application on ultrasound measurement of optic nerve sheath diameter (indirect measure of increased intracranial pressure) in laparoscopic cholecystectomy. Methods: Eighty ASA I-II patients aged between 18 and 60 years scheduled for elective laparoscopic cholecystectomy were included. The study was registered in the Australian New Zealand Clinical Trials (ACTRN12618000771257). Patients were randomly divided into either Group C (control, PEEP not applied), or Group P (PEEP applied at 10 cmH20). Optic nerve sheath diameter, hemodynamic, and respiratory parameters were recorded at six different time points. Ocular ultrasonography was used to measure optic nerve sheath diameter. Results: Peak pressure (PPeak) values were significantly higher in Group P after application of PEEP (p = 0.012). Mean respiratory rate was higher in Group C at all time points after application of pneumoperitoneum (p < 0.05). The mean values of optic nerve sheath diameters measured at all time points were similar between the groups (p > 0.05). The pulmonary dynamic compliance value was significantly higher in group P as long as PEEP was applied (p = 0.001). Conclusions: During laparoscopic cholecystectomy, application of 10 cmH2O PEEP did not induce a significant change in optic nerve sheath diameter (indirect indicator of intracranial pressure) compared to no PEEP application. It would appear that PEEP can be used safely to correct

Comparison of the i-gelTM and the Laryngeal Mask Airway ClassicTM in terms of clinical performance / Comparação da máscara laríngea i-gel (i-gelTM) com a máscara laríngea clássica (LMA-ClassicTM) em relação ao desempenho clínico

ABSTRACTPURPOSE: The i-gelTM is one of the second generation supraglottic airway devices. Our study was designed to compare the i-gel and the Laryngeal Mask Airway ClassicTM with respect to the clinical performance.METHODS: We compared the performance of the i-gel with that of the Laryngeal Mask Airway Classic in 120 patients undergoing urologic surgery during general anesthesia without muscle relaxant with respect to the number of attempts for successful insertion, insertion time, peak airway pressure, incidence of regurgitation, fiberoptic glottic view and postoperative complications. Second generation supraglottic airway devices were inserted by the same anesthesiologist, experienced in use of both devices (>200 uses and first time failure rate <5%). Methylene blue method was used to detect gastric regurgitation.RESULTS: There was no statistical difference between the two groups regarding the success of insertion of second generation supraglottic airway device (p = 0.951). The laryngeal mask insertion time for the i-gel group was significantly shorter than that for the Laryngeal Mask Airway Classic group (11.6 ± 2.4 s versus 13.1 ± 1.8 s [p = 0.001]). The fiberoptic glottic view scores for the i-gel group was significantly better than that for the ones for the Laryngeal Mask Airway Classic group (p = 0.001). On fiberoptic view, there was no sign of methylene blue dye at any time point in either group. In addition, there was no difference between the groups in patient response regarding the presence of a sore throat when questioned 24 h after the procedure (p = 0.752).CONCLUSION: Both devices had good performance with low postoperative complications and without occurrence of regurgitation. The i-gel provided a shorter insertion time and a better fiberoptic view than the Laryngeal Mask Airway Classic.

RESUMOJUSTIFICATIVA E OBJETIVO: A i-gel é um dos dispositivos supraglóticos de segunda geração para o manejo das vias aéreas. Nosso estudo foi projetado para comparar a i-gelTM e a máscara laríngea clássica (Laryngeal Mask Airway ClassicTM, LMA-C) em relação ao desempenho clínico.MÉTODOS: Avaliamos os desempenhos de i-gel e LMA-C em 120 pacientes submetidos à cirurgia urológica sob anestesia geral sem relaxante muscular. Comparamos o número de tentativas de inserção bem-sucedidas, o tempo de inserção, a pressão de pico das vias aéreas, a incidência de regurgitação, a visibilidade da glote com o uso de fibra óptica e as complicações no pós-operatório. Os dispositivos supraglóticos de segunda geração foram inseridos pelo mesmo anestesiologista com experiência na aplicação de ambos os dispositivos (> 200 aplicações e taxa de falha na primeira tentativa < 5%). O corante azul de metileno foi usado para detectar regurgitação gástrica.RESULTADOS: Não houve diferença estatística entre os dois grupos em relação ao sucesso da inserção do dispositivo supraglótico de segunda geração (p = 0,951). O tempo de inserção da máscara laríngea no grupo i-gel foi significativamente menor do que no grupo LMA-C (11,6 ± 2,4 segundos vs. 13,1 ± 1,8 segundos, p = 0,001). O escore de visibilidade da glote via fibra óptica do grupo i-gel foi significativamente melhor do que o do grupo LMA-C (p = 0,001). Na visão via fibra ótica, sinais do corante azul de metileno não foram observados em qualquer momento em ambos os grupos. Além disso, não houve diferença entre as respostas dos grupos quando perguntados sobre a presença de dor de garganta 24 horas após o procedimento (p = 0,752).CONCLUSÃO: Ambos os dispositivos apresentaram bom desempenho, com poucas complicações no pós-operatório e sem ocorrência de regurgitação. A máscara laríngea i-gel proporcionou um tempo de inserção mais curto e uma visão via fibra óptica melhor do que a LMA-C.