Sodium bicarbonate administration during cardiac arrest. Effect on arterial pH PCO2, and osmolality
R. L. Bishop and M. L. Weisfeldt
Arterial pH, Pco2, and osmolality were determined serially during cardiac
resuscitation in patients and in dogs, with and without administration of
sodium bicarbonate. These studies demonstrate that (1) in the absence of
preexisting acidosis, severe acidosis can be prevented by adequate
ventilation alone; (2) sodium bicarbonate administration results in a
significant rise in arterial Pco2, which parallels the rise in pH despite
adequate ventilation; (3) during prolonged cardiac and resuscitation, there
is a rise in arterial osmolality that is accentuated by sodium bicarbonate.
These studies suggest that sodium bicarbonate should not be used during
resuscitation (1) in the absence of effective hyperventilation or where
carbon dioxide removal is inadequate despite adequate ventilation, (2) in
repeated doses, without confirmation of substantial acidosis, or (3) when
cardiac arrest has been of brief duration and preexisting acidosis is
unlikely. These studies also point to the need for a reappraisal of other
buffers that do not elevate the arterial Pco2.
