Chest
Volume 95, Issue 6, June 1989, Pages 1216-1221
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Clinical Investigations
Comparison of Central-Venous to Mixed-Venous Oxygen Saturation During Changes in Oxygen Supply/Demand

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Because central venous O2 saturation (superior vena cava, SCVO2) can be monitored with less patient risk than mixed venous O2 saturation (pulmonary artery, Sv¯O2), we examined the correlations between Sv¯O2 and ScvO2 over a broad range of cardiorespiratory conditions, including hypoxia, hemorrhage, and resuscitation in anesthetized dogs. The correlation coefficient (r) between Sv¯O2 and ScvO2 in 179 simultaneously drawn blood samples from 22 dogs was 0.97. In another nine dogs, the two sites were continuously and simultaneously monitored with fiberoptic catheters; r was 0.96 with a mean difference of 3.7 ± 2.9 percent (SD) saturation. In each dog the changes in ScvO2 closely paralleled the changes in Sv¯O2. Although absolute values of ScvO2 are not sufficiently identical to Sv¯O2 to calculate O2 uptake or pulmonary shunt precisely, close tracking of changes in the two sites across a wide range of hemodynamic conditions warrant further consideration of ScvO2 for patient monitoring of trends in O2 supply/demand.

Section snippets

METHODS

Thirty-eight mongrel dogs of either sex (av wt, 18 ± 2 kg) were anesthetized with pentobarbital sodium (30 mg/kg IV), with supplemental doses given as needed. They were intubated and ventilated with a Harvard respirator at ten breaths/min and a tidal volume sufficient to maintain arterial PCO2 at 35 to 40 mm Hg. The animals were paralyzed with succinylcholine chloride. Systemic and PA pressures, heart rate, and ECG were continuously recorded.

In the first series of experiments (n = 24)

RESULTS

In vitro O2 Saturation Measurements

The correlation between Sv¯O2 and ScvO2 for the first series of experiments obtained from intermittent simultaneous blood sampling is shown in Figure 1. The individual correlation coefficients between the two sites for each of 22 dogs ranged from 0.92 to 0.99. The various experimental interventions, from hyperoxia to severe hypoxia, produced a range in venous O2 saturation from greater than 80 percent to less than 10 percent. When changes in O2 saturation

DISCUSSION

The O2 saturation values for the pulmonary artery and superior vena cava were generally in close accordance throughout all the experimental conditions of this study. Furthermore, during abrupt changes in the oxygen supply to demand ratio, changes in ScvO2 matched changes in Sv¯O2 almost immediately. Hypoxia caused the greatest divergence of values with an average difference of –6 percent saturation and a worse-case difference of –20 percent. ScvO2 was expected to be slightly lower

ACKNOWLEDGMENTS

Fiberoptic catheters and O2 saturation monitors were provided by Baxter Edwards Corp., Irvine, CA. Dopexamine was generously supplied by Fisons plc, Loughborough, UK.

REFERENCES (29)

  • RobinED.

    Death by pulmonary artery flow-directed catheter [Editorial]

    Chest

    (1987)
  • GoreJM et al.

    A community-wide assessment of the use of pulmonary artery catheters in patients with acute myocardial infarction

    Chest

    (1987)
  • BaelePL et al.

    Continuous monitoring of mixed venous oxygen saturation in critically ill patients

    Anesth Analg

    (1982)
  • DivertieMB et al.

    Continuous monitoring of mixed venous oxygen saturation

    Chest

    (1984)
  • ReinhartK et al.

    Physiologische Grundlagen and klinische Erfahrungen mit der kontinuierlichen In vivo-Registrierung der gemischtve-nösen Sauerstoffsättigung bei Risikopatienten

    Intensivmed

    (1986)
  • WallerJL et al.

    Clinical evaluation of a new fiberoptic catheter oximeter during cardiac surgery

    Anaesth Analg

    (1982)
  • KandelG et al.

    Mixed venous oxygen saturation

    Arch Intern Med

    (1983)
  • NelsonLD.

    Continuous venous oximetry in surgical patients

    Ann Surg

    (1986)
  • ReinhartK.

    Zum Monitoring des Sauerstofftransportsystems

    Anaesthesist

    (1988)
  • RobinED.

    Defenders of the pulmonary artery catheter

    Chest

    (1988)
  • PuriVK et al.

    Complications of vascular catheterization: a prospective study

    Crit Care Med

    (1980)
  • GoldmanRH et al.

    Measurement of central venous oxygen saturation in patients with myocardial infarction

    Circulation

    (1968)
  • ScheinmanMM et al.

    Critical assessment of use of central venous oxygen saturation as a mirror of mixed venous oxygen in severely ill cardiac patients

    Circulation

    (1969)
  • LeeJ et al.

    Central venous oxygen saturation in shock: a study in man

    Anesthesiology

    (1972)
  • Cited by (0)

    Supported by NHLBI grants HL14693, HL26927, and 5T32HL0755305, and Braun Melsungen Foundation (Germany).

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