Objective: To determine the oxygen outflow delivered by seven different models of manually operated self-inflating resuscitation bags (with and without an oxygen reservoir connected), which were tested using different oxygen supply rates without manipulating the bag, by simulating their use in patients breathing spontaneously. Methods: The oxygen outflow was measured using a wall oxygen flow meter and a flow meter/respirometer attached to the bag, together with another flow meter/respirometer attached to the patient connection port. The resuscitation bags that allow the connection of an oxygen reservoir were tested with and without this device. All resuscitation bags were tested using oxygen supply rates of 1, 5, 10, and 15 L/min. Statistical analyses were performed using analysis of variance and t-tests. Results: The resuscitation bags that allow the connection of an oxygen reservoir presented a greater oxygen outflow when this device was connected. All resuscitation bags delivered a greater oxygen outflow when receiving oxygen at a rate of 15 L/min. However, not all models delivered a sufficient oxygen outflow even when the two previous conditions were satisfied. Conclusions: Of the resuscitation bags studied, those that allow the connection of an oxygen reservoir must have this reservoir connected to the bag when used as a source of oxygen in nonintubated spontaneously breathing patients. All of the models studied should receive oxygen at a rate ≥ 15 L/min. It is not safe to use manually operated self-inflating resuscitation bags for this purpose without knowing their characteristics.

Keywords: Oxygen/administration & dosage; Resuscitation; Equipment and supplies; Respiration; Intensive care.

Objective: The purpose of this study was to investigate endotracheal tube cuff pressure (Pcuff) alteration in patients under mechanical ventilation after changes in position. Methods: All selected patients were initially placed in the 35° semi-Fowler position, with Pcuff adjusted to 20 mmHg, and randomly divided into two groups. Group A, in which patients were moved to the lateral decubitus position, facing away from the ventilator (measurement designated Pcuff A1), returned to the initial position (measurement designated Pcuff A2), moved to a lateral decubitus position, facing the ventilator (measurement designated Pcuff A3) and then returned to the initial position (measurement designated Pcuff A4); and Group B, in which patients were moved to the lateral decubitus position, facing the ventilator (measurement designated Pcuff B1), returned to the initial position (measurement designated Pcuff B2), moved to the lateral decubitus position; facing away from the ventilator (measurement designated Pcuff B3) and then returned to the initial position (measurement designated Pcuff B4). Results: The study comprised 70 patients, 31 allocated to group A and 39 allocated to group B. Values >22 mmHg were observed in 142(50.7%) of the 280 Pcuff measurements taken, and values <18 mmHg were observed in 14 (5%). When moved from the 35° semi-Fowler position to the lateral decubitus position, facing away from the ventilator, 58 (82.2%) of the patients presented mean Pcuff values in the higher range (>22 mmHg). Conclusions: Changes in body position can cause significant Pcuff variations in patients under mechanical ventilation.

Keywords: Pressure; Intubation, intratracheal; Posture; Supine position.

Objective: To assess possible alterations in the tidal volume and peak inspiratory pressure delivered by seven models of manually operated self-inflating resuscitation bags as a function of the oxygen supply rate used. Methods: The resuscitation bags tested were the following: Oxigel, models A and B; CE Reanimadores; ProtecSolutions; Missouri; Axmed; and Narcosul. For the measurements, a wall oxygen flow meter, a flow meter/respirometer, a resuscitation bag, a sensor (Tracer 5 unit), and a test lung were connected. In addition, the Tracer 5 unit was connected to a notebook computer. Oxygen supply rates of 1, 5, 10, and 15 L/min were used. Results: The tidal volume delivered by the Oxigel model A resuscitation bag when receiving oxygen at a rate of 15 L/min was approximately 99% greater than that delivered when receiving oxygen at a rate of 1 L/min. Similarly, peak inspiratory pressure was approximately 155% greater. Under the same conditions, the tidal volume delivered by the Narcosul resuscitation bag was 48% greater, and peak inspiratory pressure was 105% greater. The remaining resuscitation bags tested showed no significant alterations in the tidal volume or peak inspiratory pressure delivered. Conclusions: Under the resistance and compliance conditions used, the resuscitation bags in which the oxygen inflow is directed to the interior of the bag had the patient valve stuck at the inspiratory position when receiving oxygen at a rate ≥ 5 L/min, significantly increasing the tidal volume and peak inspiratory pressure delivered. This did not occur with the resuscitation bags in which the oxygen inflow is directed to the exterior of the bag.

Keywords: Oxygen/administration & dosage; Resuscitation; Equipment and supplies; Pulmonary ventilation; Intensive care.