Comparison of commercial and noncommercial endotracheal tube-securing devices.

BACKGROUND: Tracheal intubation is used to establish a secure airway in patients who require mechanical ventilation. Unexpected extubation can have serious complications, including airway trauma and death. Various methods and devices have been developed to maintain endotracheal tube (ETT) security. Associated complications include pressure ulcers due to decreased tissue perfusion. Device consideration includes ease of use, rapid application, and low exerted pressure around the airway. METHODS: Sixteen ETT holders were evaluated under a series of simulated clinical conditions. ETT security was tested by measuring distance displaced after a tug. Nine of the 16 methods could be evaluated for speed of moving the ETT to the opposite side of the mouth. Sensors located on a mannequin measured applied forces when the head was rotated vertically or horizontally. Data were analyzed using multivariate analysis of variance, with P < .05. RESULTS: Median displacement of the ETT by the tug test was 0 cm (interquartile range of 0.0-0.10 cm, P < .001). The mean time to move the ETT from one side of the mouth to the other ranged from 1.25 ± 0.2 s to 34.4 ± 3.4 s (P < .001). Forces applied to the face with a vertical head lift ranged from < 0.2 newtons (N) to a maximum of 3.52 N (P < .001). Forces applied to the face with a horizontal rotation ranged from < 0.2 N to 3.52 N (P < .001). Commercial devices produced greater force than noncommercial devices. CONCLUSIONS: Noncommercial airway holders exert less force on a patient's face than commercial devices. Airway stability is affected by the type of securing method. Many commercial holders allow for rapid but secure movement of the artificial airway from one side of the mouth to the other.

Performance comparison of 15 transport ventilators.

BACKGROUND: Numerous mechanical ventilators are designed and marketed for use in patient transport. The complexity of these ventilators differs considerably, but very few data exist to compare their operational capabilities. METHODS: Using bench and animal models, we studied 15 currently available transport ventilators with regard to their physical characteristics, gas consumption (duration of an E-size oxygen cylinder), battery life, ease of use, need for compressed gas, ability to deliver set ventilation parameters to a test lung under 3 test conditions, and ability to maintain ventilation and oxygenation in normal and lung-injured sheep. RESULTS: Most of the ventilators tested were relatively simple to operate and had clearly marked controls. Oxygen cylinder duration ranged from 30 min to 77 min. Battery life ranged from 70 min to 8 hours. All except 3 of the ventilators were capable of providing various F(IO2) values. Ten of the ventilators had high-pressure and patient-disconnect alarms. Only 6 of the ventilators were able to deliver all settings as specifically set on the ventilator during the bench evaluation. Only 4 of the ventilators were capable of maintaining ventilation, oxygenation, and hemodynamics in both the normal and the lung-injured sheep. CONCLUSIONS: Only 2 of the ventilators met all the trial targets in all the bench and animal tests. With many of the ventilators, certain of the set ventilation parameters were inaccurate (differed by > 10% from the values from a cardiopulmonary monitor). The physical characteristics and high gas consumption of some of these ventilators may render them less desirable for patient transport.

The impact of closed endotracheal suctioning systems on mechanical ventilator performance.

BACKGROUND: Closed endotracheal suctioning during mechanical ventilation is increasingly used, but its impact on ventilator function has not been fully studied. METHODS: We evaluated the impact of closed suctioning with 11 critical-care ventilators, during assisted ventilation in pressure-support mode, pressure-assist/control mode, volume-assist/control mode, and during continuous positive airway pressure, with 2 suctioning pressures (-120 mm Hg and approximately -200 mm Hg), and with 2 tidal volumes (450 mL and 900 mL). We continuously measured airway pressure, flow at the airway, and pressure distal to the catheter tip, before, during, and after a single 15-second period of continuous suctioning. RESULTS: No ventilator malfunctioned as a result of the closed suctioning. During suctioning, end-expiratory pressure markedly decreased in all modes, and peak flow increased in all modes except volume-assist/control (p < 0.001). Respiratory rate increased during suctioning in pressure- and volume-assist/control (p < 0.001) but not during pressure support or continuous positive airway pressure. Gas delivery was most altered during volume-assist/control with the smaller tidal volume (p < 0.05) and least altered during pressure-assist/control with the larger tidal volume. CONCLUSION: There are large differences between the ventilators evaluated (p < 0.001). Closed suctioning does not cause mechanical ventilator malfunction. Upon removal of the suction catheter, these ventilators resumed their pre-suctioning-procedure gas delivery within 2 breaths, and, during all the tested modes, all the ventilators maintained gas delivery. However, closed suctioning can decrease end-expiratory pressure during suctioning.