0000000000037338
AUTHOR
Fritz Mertzlufft
Tentative Recommendation on Terminology and Definitions in Respiratory Physiology: Résumé of the Isott Consensus Session 1992
1 The use of small letters for the symbols “p” (partial pressure), “s” (saturation) and “c” (concentration) (e.g. pO2, sO2, cO2) follows recommendations of the IFCC and IUPAC [4]. This supports the use of contemporary word processing systems and mostly eliminates the need to use subscripts (except for chemical valencies: e.g. O2, CO2, H2CO3 etc.). The potential risk of misinterpretations and double meanings is reduced also (e.g. “cO2” [oxygen concentration] v.s. “CO2” [carbon dioxide] and “sO2” [oxygen saturation] v.s. “sO2” [sulfur dioxide]). 2 The symbol shall include the site of measurement or description, e.g. paO2 (arterial O2 partial pressure), svO2 (mixed venous oxygen saturation), o…
Optimal Pre-Oxygenation: The Nasoral-System
The human body’s intra-and extrapulmonary O2 reserves, i.e. the oxygen stores of the functional residual capacity (FRC) and the blood, will be rapidly depleted during any kind of respiratory arrest (apnea). Application of oxygen prior to iatrogenic apnea (e.g. for endotracheal intubation procedures), therefore, commonly is discussed [e.g. Miller, 1990] as the proposed measure designed to achieve an increase in the human body’s oxygen stores sufficient to avoid hypoxemia. This prophylactic application of oxygen simply has become to be termed “pre-oxygenation”, regardless of the amount of increase in the O2 stores actually achieved. A myriad of different techniques and procedures are practica…
Clinical Use of Oxygen Stores: Pre-oxygenation and Apneic Oxygenation
During states of respiratory arrest the human oxygen stores may be used therapeutically, regardless of the origin, i.e. either prior to the routinely induced apnea for endotracheal intubation or as an emergency measure in any other case of apnea. The present considerations focus on the clinical use of the oxygen stores available, applying.
Hyperoxic Intubation Apnoea: An In Vivo Model for the Proof of the Christiansen-Douglas-Haldane Effect
The Christiansen-Douglas-Haldane effect (HALDANE effect) describes the different CO2 binding capacity of haemoglobin on its degree of oxygenation and was first demonstrated in vitro in 1914 (Christiansen, Douglas and Haldane, 1914).
Determination Of Pulmonary Parameters (V̇A, $$ {D_{{L_{{O^2}}}}} $$ ) From Arterial O2 and CO2 Partial Pressures During Exercise
The arterial O2 and CO2 partial pressures mainly depend on the ventilation-perfusion ratio VA/Q and on the O2 diffusing capacity-perfusion ratio DLO2/Q. According to RAHN’s VA/Q concept, the dependence of the alveolar O2 and CO2 partial pressures on the ventilation-perfusion ratio can be determined graphically, and displayed in the form of a diagram (2,3). However, the application of the RAHN diagram is limited by the fact that during the passage of the blood through the lung capillaries, a complete adjustment of the capillary O2 partial pressure to the alveolar value frequently does not occur. This is particularly valid for gas exchange during exercise. For this case, the alveolar-endcapil…