Abstract: A disposable pressure gauge comprises a pair of bellows members, a returning member that tends to return the bellows members to a base-line position, and a housing member that contains the pair of bellows member and returning member. The pair of bellows members and housing member have apertures disposed in such a way that the gauge measures both positive and "negative" pressure, relative to atmospheric pressure, and is pre-calibrated, inexpensive, portable and disposable, thereby avoiding a need for heavy, expensive conventional manometers that must frequently be sterilized and recalibrated. In use, the gauge is attached to an endotracheal tube, and optionally to a resuscitator bag via the endotracheal tube. Color coordination aids in use of the gauge. Attachment of the gauge will not adversely affect the operation of such a resuscitator bag.