Duration of Carbon Dioxide Absorption by Soda Lime at Low Rates of Fresh Gas Flow Maria Ohm, MD,* Nikolaus Gravenstein, Michael L. Good, MD$ Departments
of Anesthesiology
of Medicine,
Gainesville,
and Neurosurgery,
Study Objective:
To determine
the impact
of a low fresh
duration
dioxide
absorption
by soda lime.
of carbon
(CO,)
u test lung with a CO, inflow 0.5,
interface
was determined
with a mainstream
each fresh considered
in Anesthesiology
*Assistant
in Anesthesiology
Professor
circle ventilating
Fresh gas,flow
Duration
rates of 0.25,
CO, tension
The times of this interual
min than at 1 Llmin fresh
gas flow and at 1 Llmin
circuit
of CO, absorption
(PICO,)
to increase from
were recorded four
gas flow rate and compared by analysis of variance; significant. Time to soda lime failure was significantly
and
Conclusion: breathing
Because
circle
the CO, absorbent
Address reprint requests to at the Editorial Office, Anesthesiology, Box J-254, Health Center, Gainesville, C’SA.
Dr. Gravenstein Department of J. Hillis Miller FL 32610-0254,
Received for publication March 28, 1990; revised manuscript accepted for publication September 28, 1990. 0 199 1 Butterworth-Heinemann
J. Clin.
breathing
rate on the
times for
p < 0.05 was longer at 2 Ll
than at 0.25 Llmin fresh
gas
flow.
tAssociate Professor Neurosurgery
104
cupnometer.
as the time for the inspired
0 mm to 7 mm of mercury.
of
and a semiclosed
of 250 ml per minute.
gas jlow
were studied. and Main Results: CO, was measured at the breathing
Measurements
Department
College
1, 2, und 4 Limin
test lung
Medicine,
of Florida
FL.
Design: Nonclinical, experimental. Setting: Experimental laboratory. Methods: In vitro test with Sodasorb
*Resident in Anesthesiology
University
MD,-!
Anesth.,
vol. 3, March/April
soda lime color indicators
is used at a low rate qf fresh must be replaced
Keywords: Anesthesia; equipment; supplies.
are unreliable,
when a semiclosed
gas flow without CO, monitoring,
more frequently.
blood gas monitoring;
carbon dioxide;
Introduction Economic considerations,l operating room (OR) pollution control,” heat and moisture conservation,“,’ and closed-circuit anesthesia have contributed to the increasing use of lower rates of fresh gas flow (i.e.,
of Anesthesiology
of Medicine,
Gainesville,
and Neurosurgery,
Study Objective:
To determine
the impact
of a low fresh
duration
dioxide
absorption
by soda lime.
of carbon
(CO,)
u test lung with a CO, inflow 0.5,
interface
was determined
with a mainstream
each fresh considered
in Anesthesiology
*Assistant
in Anesthesiology
Professor
circle ventilating
Fresh gas,flow
Duration
rates of 0.25,
CO, tension
The times of this interual
min than at 1 Llmin fresh
gas flow and at 1 Llmin
circuit
of CO, absorption
(PICO,)
to increase from
were recorded four
gas flow rate and compared by analysis of variance; significant. Time to soda lime failure was significantly
and
Conclusion: breathing
Because
circle
the CO, absorbent
Address reprint requests to at the Editorial Office, Anesthesiology, Box J-254, Health Center, Gainesville, C’SA.
Dr. Gravenstein Department of J. Hillis Miller FL 32610-0254,
Received for publication March 28, 1990; revised manuscript accepted for publication September 28, 1990. 0 199 1 Butterworth-Heinemann
J. Clin.
breathing
rate on the
times for
p < 0.05 was longer at 2 Ll
than at 0.25 Llmin fresh
gas
flow.
tAssociate Professor Neurosurgery
104
cupnometer.
as the time for the inspired
0 mm to 7 mm of mercury.
of
and a semiclosed
of 250 ml per minute.
gas jlow
were studied. and Main Results: CO, was measured at the breathing
Measurements
Department
College
1, 2, und 4 Limin
test lung
Medicine,
of Florida
FL.
Design: Nonclinical, experimental. Setting: Experimental laboratory. Methods: In vitro test with Sodasorb
*Resident in Anesthesiology
University
MD,-!
Anesth.,
vol. 3, March/April
soda lime color indicators
is used at a low rate qf fresh must be replaced
Keywords: Anesthesia; equipment; supplies.
are unreliable,
when a semiclosed
gas flow without CO, monitoring,
more frequently.
blood gas monitoring;
carbon dioxide;
Introduction Economic considerations,l operating room (OR) pollution control,” heat and moisture conservation,“,’ and closed-circuit anesthesia have contributed to the increasing use of lower rates of fresh gas flow (i.e.,
