Ventilation is the mechanical process whereby air is taken into and out of the lungs. Situations in which a patient might require venitlatory support range from apnea to patients experiencing depressed respiratory function. If the patients rate of breathing decreases significantly it can lead to hypercarbia, hypoxia, a lowered pH level and a decrease in respiratory minute volume. This can result in cardiac or respiratory arrest if it isnt corrected. Expired air ventilation has been accepted as the technique of choice since the late 1950s. It has been shown to be an effective practice for both professionals and lay persons including young children over 5 years of age. Ventilation using the expired air of the rescuer can be applied to the mouth or nose of the adult victim and to the mouth and nose of the infant. Mouth-to-Mouth ventilation and Mouth-to-Nose ventilation can provide effective ventilatory support to a patient. A major advantage of these methods of ventilation is that no equipment is required to effectively offer ventilatory support to the patient. However, the disadvantage of these methods of ventilatory support are that both methods only offer a limited oxygen supply due to the fact that oxygen expired from the rescuer will only contain 17 percent oxygen. Mouth-to-Mask Ventilation or Pocket Mask Ventilation A clear, plastic, molded facemask similar to that used in anesthesia may be used to provide mouth to mask ventilation. A unidirectional valve diverts the patient's expired air away from the rescuer and traps any macroscopic particles emerging from the patient. This valve improves the aesthetics and reduces risk of cross infection. The mouth to mask method is a two handed technique which produces a better seal than that obtained during single-person bag-valve-mask ventilation. As with mouth-to-mouth ventilation it is possible to generate high tidal volumes, high airway pressures and increase the risk of...
