PMID- 2035819
OWN - NLM
STAT- MEDLINE
DCOM- 19910627
LR  - 20131121
IS  - 0003-2417 (Print)
IS  - 0003-2417 (Linking)
VI  - 40
IP  - 3
DP  - 1991 Mar
TI  - [The meaningfulness of central venous blood samples. Central venous versus mixed 
      venous O2 status].
PG  - 131-44
AB  - Both mixed-venous and "central-venous" oxygen status (O2 partial pressure [pO2], 
      O2 saturation [sO2], O2 concentration [cO2], hemoglobin concentration [cHb]) are 
      often considered to adequately represent total-body oxygen supply. Since modern 
      technology has made continuously in vivo measurement possible, mixed-venous O2 
      saturation (svO2) and partial O2 saturation (psO2) have become extensively used 
      for that purpose. Both venous sites of measurement are used as diagnostic 
      adjuncts regarding hemodynamic status. However, both are associated with certain 
      problems. There is a lack of any clear definition of a "central-venous" site of 
      the catheter tip (right atrium, superior vena cava, inferior vena cava). Instead, 
      the location of the catheter tip depends upon the approach to the central venous 
      system. One must also be aware of significant migrational tendencies of the 
      catheter tip. Thus, "central-venous" samples can only represent the situation in 
      a single portion of the circulation, whereas the respective organ areas may vary 
      considerably with the same catheter from one time point to another. Furthermore, 
      the state of the coronary circulation never can be evaluated. The frequently 
      postulated correlation of mixed-venous and "central-venous" values decreases with 
      increasing deterioration of the cardiovascular system, especially in patients 
      with high cardiovascular risks. The main overall parameters of mixed-venous 
      oxygen status are oxygen content (cvO2), cardiac output (C.O.), and oxygen 
      consumption (QO2) of the tissues. The relation between arterial and mixed-venous 
      O2 status is given by Fick's principle: caO2-cvO2 = QO2/C.O. From this, it 
      becomes obvious that a relation between cvO2 and C.O. may only be presumed if QO2 
      and caO2 remain constant. Evaluation of O2 availability (AO2) using cvO2 or the 
      determining components of cvO2 seems reasonable only if the modulating influences 
      of C.O. and QO2 are taken into consideration. Therefore, any empirically deduced 
      relation between svO2 and C.O. (regardless of the origin, i.e., linear or 
      nonlinear) must be viewed as being accidental. This implies that svO2 and cvO2 
      per se are only partly helpful in evaluating the hemodynamic situation. The best 
      parameters for interpreting the cardiovascular situation seem to be arteriovenous 
      O2 difference (avDO2) and C.O. In particular, the avDO2 can be accepted as an 
      integrating parameter for AO2 and QO2, and may therefore serve as a diagnostic 
      indication of cardiovascular imbalance.
FAU - Brandt, L
AU  - Brandt L
AD  - Institut fur Anaesthesie, Kliniken der Stadt Wuppertal.
FAU - Mertzlufft, F
AU  - Mertzlufft F
LA  - ger
PT  - Comparative Study
PT  - English Abstract
PT  - Journal Article
PT  - Review
TT  - Zur Aussagekraft "zentralvenoser" Blutproben. "Zentralvenoser" vs. 
      gemischtvenoser O2-status.
PL  - Germany
TA  - Anaesthesist
JT  - Der Anaesthesist
JID - 0370525
RN  - S88TT14065 (Oxygen)
SB  - IM
MH  - Humans
MH  - Oxygen/*blood
MH  - Veins
RF  - 51
EDAT- 1991/03/01 00:00
MHDA- 1991/03/01 00:01
CRDT- 1991/03/01 00:00
PHST- 1991/03/01 00:00 [pubmed]
PHST- 1991/03/01 00:01 [medline]
PHST- 1991/03/01 00:00 [entrez]
PST - ppublish
SO  - Anaesthesist. 1991 Mar;40(3):131-44.