Evaluation of an automatized AMBU ESSI-1 INC designed at the Instituto Nacional de Cardiología Ignacio Chávez / Evaluación del AMBU automatizado ESSI-1 INC diseñado en el Instituto Nacional de Cardiología Ignacio Chávez

Abstract Objective: The objectives of this study were to evaluate an automated device for ventilatory support based on AMBU manufactured in March 2020. Methods: The ESSI-1 INC was evaluated through pulmonary mechanics and physiology parameters through compensatory spirometer tests (TISSOTs), and an artificial lung Model5600i Dual Adult PNEU VIEW SYSTEM; it was also compared to the anesthetic ventilatory support equipment (AEONMED 7500) in porcine models, measuring ventilatory, hemodynamic and gasometric parameters. Results: This equipment (ESSI-1 INC) was successfully tested by mechanical and biological models, such as pigs in which its performance was evaluated in terms of variability of tidal volume, ventilation frequency, and I/E relationship versus the manual performance of two medical interns. All the results turned out as expected and were satisfactory. Conclusions: It is safe and effective equipment and should be tested and used in diverse clinical conditions to standardize the ventilatory safety and care of patients who require it.

Resumen Objetivo: Evaluar un dispositivo automatizado para la asistencia ventilatoria basado en un AMBU manufacturado en Marzo del 2020. Métodos: El ESSI-1 INC fue evaluado por medio de parámetros fisiológicos y mecánica pulmonar a través de pruebas de espirómetro compensatorios (TISSOT); pulmón artificial (Modelo 5600i Dual Adult PNEU VIEW SYSTEM); así como su desempeño comparado a la máquina de anestesia (AEONMED 7500) en modelos porcinos, midiendo criterios ventilatorios, hemodinámicos y gasométricos. Resultados: Este equipo (ESSI-1 INC) fue exitosamente probado por modelos mecánicos y biológicos, tales como cerdos donde su desempeño fue evaluado en términos de la variabilidad del volumen tidal, frecuencia ventilatoria, y relación I/E versus el desempeño manual de dos médicos. Todos los resultados finalizaron como se esperaba de forma satisfactoria. Conclusiones: Es un equipo seguro y efectivo, el cual debería ser probado y usado en distintas condiciones clínicas para estandarizar la seguridad ventilatoria y cuidado de pacientes que lo requieran.

A Comparison of Manual and Mechanical Ventilation in Terms of the Adequacy of Ventilation during Intrahospital Transport of Neurosurgical Patients in the Immediate Postoperative Period / 대한마취과학회지

BACKGROUND: Ambu-bags and portable ventilators can provide intubated patients with ventilation during intrahospital transport, where it is desirable to maintain normocarbia. This study was designed to compare the amount of variation in ventilation that occur during the intrahospital transport of neurosurgical patients ventilated either manually or with a portable ventilator. METHODS: 40 patients were randomized to receive either manual ventilation (Group A, n = 20) during transport or ventilation by a portable ventilator (Group P, n = 20) during the immediate postoperative period. In group A, an adult laerdal resuscitator bag with a reservoir bag (2,600 ml) was used and oxygen (15 L/min) was supplied from a portable oxygen tank. In group P, a portable ventilator was set to controlled mechanical ventilation or synchronized intermittent mandatory ventilation mode, 8.5-10 ml/kg of tidal volume, 1:2 of inspiratory to expiratory ratio, and 100% oxygen concentration. Respiratory rates were adjusted to maintain normocarbia. Hemodynamic parameters were recorded before and during transport. Arterial blood gas levels were also obtained before and during transport. RESULTS: PaCO2 during transport was significantly lower in Group A than in Group P (P < 0.05). Manually ventilated patients showed greater deviations from normocarbia (35-45 mmHg) than mechanically ventilated patients (P < 0.01). PaO2 during transport was no different in the two groups. Blood pressure and heart rates during transport increased significantly in both groups versus before transport (P < 0.01). CONCLUSIONS: The use of a portable ventilator can effectively maintain normocarbia and produce the stable ventilatory pattern during the intrahospital transport of neurosurgical patients during immediate postoperative period.

Effects of Isoflurane on Hypoxic Pulmonary Vasocontriction in Human during One Lung Ventilation / 대한마취과학회지

BACKGROUND: AMBU bag is a useful equipment in the cardiopulmonary resuscitation(CPR) and respiratory therapy. The volume delivered during ventilation with AMBU bag may be influenced by many factors. METHOD: We evaluated the effects of ventilation method(one-hand, open-palm, two-hand) and resuscitator's sex on volume in 30 intubated patients under general anesthesia with inhalational anesthetics and muscle relaxants. RESULTS: Mean tidal volume was significantly greater with two-hand method than one-hand and open-palm method in both sex. PaO2 was significantly decreased in all ventilation methods. PaCO2 was also decreased and pH was increased in all methods. CONCLUSION: The results suggest that all ventilation methods with AMBU bag in intubated patients may suitable in the CPR. If airway management by intubation is impossible and mask ventilation, two-hand method may be effective in both resuscitator but open-palm method may not suitable to female resuscitator.

Effects of Isoflurane on Hypoxic Pulmonary Vasocontriction in Human during One Lung Ventilation / 대한마취과학회지

BACKGROUND: AMBU bag is a useful equipment in the cardiopulmonary resuscitation(CPR) and respiratory therapy. The volume delivered during ventilation with AMBU bag may be influenced by many factors. METHOD: We evaluated the effects of ventilation method(one-hand, open-palm, two-hand) and resuscitator's sex on volume in 30 intubated patients under general anesthesia with inhalational anesthetics and muscle relaxants. RESULTS: Mean tidal volume was significantly greater with two-hand method than one-hand and open-palm method in both sex. PaO2 was significantly decreased in all ventilation methods. PaCO2 was also decreased and pH was increased in all methods. CONCLUSION: The results suggest that all ventilation methods with AMBU bag in intubated patients may suitable in the CPR. If airway management by intubation is impossible and mask ventilation, two-hand method may be effective in both resuscitator but open-palm method may not suitable to female resuscitator.

The Effects of Patterns of AMBU bag Ventilation on the Inspiratory Oxygen Concentration / 대한마취과학회지

The AMBU bag is a useful equipment at the cardiopulmonary resuscitation (CPR) or the respiratory therapy. The AMBU bag eonsists simply of a self-reflating bag, a patient valve and a inlet valve. The patient valve is a non-rebreathing valve and the self-inflating bag is a recoiled rubber bag. The inlet valve on the posterior site of self-inflstion bag is closed during the bag is squeezed, and opened during the bag is released. During reflation of bag, fresh room air through the one-way valve and fresh oxygen through the orifice for oxygen supply will mix. Therefore the inspiratory oxygen concentration is decided by a speed of re- flation of the self-reflating bag. We measured inspiratory oxygen concentration during AMBU bag ventilation under different inspiration : expiration (I:E) ratio, frequency of venti- lation, ventilatory volume and flow rate of oxygen. The results were that factors increase a inspirstory oxygen concentration are 1) decrease of I:E ratio, 2) decrease of frequency of ventilation, 3) decrease of ventilatory volume, 4) inerease of flow rate. We found that haste of physician makes frequent squeezing of AMBU bag and the haste results a decrease of inspiratory oxygen concentration.