V . O2 is identical to tissue V . O2. This is extremely diffi cult to achieve clinically, particularly in mechanically ventilated subjects. Also determination of V . O2 becomes progressively less accurate as FIO2 increases. Various alternative means of measuring V . O2 which overcome some of these diffi culties are available and may be more appropriate for clinical use. For example, a pneumotac...

TRuTH IS more likely to come out of error than confusion. Lavoisier's assumption that combustion occurred in the lungs did not go unchallenged, but blood gas analysis remained uncertain until the physicist, Gustav Magnus, introduced a reliable vacuum pump. Physiologists, from Bernard and Ludwig down, joined in the investigation, and then, just as tissue metabolism was established, came Haldane'...

Acid-base physiology is among the most complex topics in clinical medicine. Disturbances of this system are common in the critically ill, and important clinical decisions based on measured acid-base parameters occur on a daily, even hourly basis. Therefore, a sound understanding of acid-base physiology is mandatory for the intensivist. The field is full of complicated concepts and equations tha...