Sir,The traditional ambu resuscitator (AR) is constructed with a semirigid self-inflating reservoir bag, which allows for hand ventilation of patients. This device is utilized with either a tight-fitting face mask or a tracheal tube. However, the AR does not allow for detection of a patient's spontaneous ventilation. Other “portable” anesthesia circuits, such as the Mapleson D or Jackson-Reese, allow for the detection of a patient's spontaneous breathing by making use of collapsible reservoir bags.[1]The principle advantage, of the AR, is that it can provide room air in the event that oxygen is not available. Whereas those systems, which utilize collapsible bags, will not allow for the entrainment of room air should their associated oxygen supplies fail.A typical AR has been modified by incorporating an incentive spirometer. This allows for the detection and volume assessment of a patient's spontaneous breathing and is illustrated in the accompanying Figure 1. This early-stage prototype has been developed by a modification of the positive end-expiratory pressure (PEEP) valve connector located within the AR. Furthermore, the incorporation of the incentive spirometer does not interfere with the entrainment of room air in the event of an oxygen supply failure.
Figure 1
An ambu resuscitator has been prototypically modified by incorporating an incentive spirometer, which assists in the detection of spontaneous respiration
An ambu resuscitator has been prototypically modified by incorporating an incentive spirometer, which assists in the detection of spontaneous respirationAdditional development of this device would continue to allow for a cost-effective means of assessing spontaneous ventilation while preserving the established clinical safety of the AR. Ultimately, an improved AR would allow for the measurement of minute ventilation, spontaneous ventilation, and possibly detect an oxygen disconnect.[2]
Figure 1