Polarografia

Historical Review

HISTORY OF BLOODGAS ANALYSIS.
IV. LELANDCLARK'SOXYGENELECTRODE
John W. Severinghaus, MD,*
and Poul B. Astrup, Dr med]"

Severinghaus JW, Astrup PB. History of blood gas analysis.
IV. The Clark oxygen electrode.
J Clin Monk 1986;2:125-139
ABSTRACT. T he electrochemical reduction of oxygen was dis-

covered by Heinrich Danneel and Walther Nernst in 1897.
Polarographyusing dropping mercury was discovered accidentally by Jaroslav Heyrovsky in Prague in 1922. This
method produced the first measured oxygen tension values in
plasma and blood in the 1940s. Brink, Davies, and Bronk
implanted platinum electrodes in tissue to study oxygen supply, or availability, from about 1940, but these bare electrodes
became poisoned when immersed in blood. Leland Clarksealed a platinum cathode in glass and covered it first with
cellophane; he then tested silastic and polyethylene membranes. In 1954 Clark conceived and constructed the first
membrane-covered oxygen electrode having both the anode
and cathode behind a nonconductive polyethylene membrane.
The limited permeability of polyethylene to oxygen reduced
depletion of oxygen from the sample, makingpossible quantitative measurements of oxygen tension in blood, solutions,
or gases. This invention led to the introduction of modern
blood gas apparatus.
KEY WORDS. M easurement techniques: electrodes, polaro-

graphic, membrane, dropping mercury; cathodes, oxygen.
Brain: oxygen waves.

" O x y g e n is Like L o v e " was the title o f Leland Clark's
paper at the M a r b u r g S y m p o s i u mon Transcutaneous
Blood Gas Monitoring [1]. Referring to a popular English song, he said he hoped that Priestley, Lavoisier,
Scheele, Faraday, Nernst, and H e y r o v s k y would smile
as he played this music:
Love is like oxygen, love is like oxygen.
You get too much, you get too high, too high.
Not enough and you're gonna die, gonna die.

* From the Department of Anesthesia and theAnesthesia Research
Center, University of California Medical Center, San Francisco, CA.
tProfessor Emeritus, Department of Clinical Chemistry, Rigshospital, University of Copenhagen, Copenhagen, Denmark.
Received Nov t, 1985, and in revised form Nov. 18. Accepted for
publication Nov 20, 1985.
Address correspondence to Dr Severinghaus, Anesthesia Research
Center, 1386 HSE, University of CaliforniaMedical Center, San
Francisco, CA 94143.

Mountaineers eagerly climb to their hypoxic limits,
w o o e d not only by the scenery and the publicity but
also by the subtle euphoria o f hypoxia. Surely blood
oxygen tension (Po2) or saturation will soon be measured on the s u m m i t o f M o u n t Everest, where a climber's inspired POE is only 29% that at sea level.
O x y g e n is addicting;in its grip are all the mitochondria-rich eukaryotes w h o learned to depend on it during
the past 1.4 billion years. This, the first atmospheric
pollutant, is the waste product o f stromatolites (formations o f algal plankton), which excreted it at least 2.3
billion years ago. Since then, all sediments have been
rusted or oxidized. O x y g e n is toxic. It rusts a person in
a century or less.With oxygen came the danger, and the
blessing, o f fire. I f introduced today, this gas might
have difficulty getting approved by the Food and Drug
Administration.
125

126 Journal of Clinical Monitoring Vol 2 No 2 April 1986

PREELECTRODEMETHODSOF BLOODGAS ANALYSIS

G ases have been extracted from blood by vacuum for
more than 300 years. For some 200 years, the identity o f
thesegases has been known, and for more than 150
years, with the introduction and improvement o f blood
pumps, the amounts have been measured with increasing precision. Initially, however, these measurements o f
blood gas content contributed relatively little to patient
care. Cyanosis and blood color were easier to measure
and offered more to the detection and treatment o f hypoxia, particularly...