Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0085383 (hypocapnia)
 1,697 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In 660 supine, intubated and anaesthetized, healthy patients scheduled for various elective surgical procedures, the distribution of arterial carbon dioxide tension (PaCO2) was investigated during manual non-monitored ventilation. The study comprised six equal groups: group 1: ventilation with a circle circuit absorber system; group 2: ventilation with the Hafnia A circuit using a total fresh gas flow (FGF) of 100 ml . kg-1 . min-1; groups 3-6: ventilation with a Hafnia D circuit with fresh gas flows of 100, 80, 70 and 60 ml . kg-1 . min-1, respectively. The mean PaCO2's of the first three groups were situated in the lower range of normocapnia (the observations in the first group having the greatest total range), whereas the rebreathing (Hafnia A and D) circuits resulted in a clustering of observed data. Employing the rebreathing circuits, protection against hypocapnia can be achieved by lowering the fresh gas flow. The most satisfying result was obtained with the Hafnia D circuit with a fresh gas flow of 70 ml . kg-1 . min-1 resulting in normocapnia with a modest and limited spread towards hypo- and hypercapnia. FGF in excess of this level must be considered as wasted. The study indicates that corrections of fresh gas flows for age are superfluous. Use of relaxants and type of surgery had no influence on the observations.
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PMID:Arterial carbon dioxide tensions during anaesthesia with manual ventilation. A descriptive study of the effects of various non-polluting circuits. 3 15

The effects of varying ventilations (VE) and fresh gas flows (FGF) on end-expiratory CO2 (FECO2) levels were investigated in an experimental model lung, employing the Hafnia modification of the Mapleson A and D anaesthetic systems during CO2-absorption and CO2-wash-out (rebreathing). Identical results were found in both systems: FECO2 was constant and independent of FGF with CO2-absorption and constant VE, whereas rebreathing resulted in increasing FECO2 levels as FGF was decreased. As control of FECO2 in the rebreathing systems by regulating FGF could only take place within FECO2 levels higher than that determined by VE at complete CO2-absorption, e.g. for the Hafnia A and D rebreathing systems, control of FGF necessitates relative hyperventilation. FECO2 with constant FGF decreased with increasing VE during CO2-absorption, as well as during rebreathing, although this decrease was less in the rebreathing systems. Thus a decrease in FECO2 with rising VE can be avoided and hypocapnia prevented. The results agree with those obtained in clinical studies.
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PMID:Control of carbon dioxide in modified Mapleson A and D (Hafnia) anaesthetic systems. An experimental model. 679 19