2004 OPEN FORUM Abstracts
EVALUATION OF SEASONAL PRESENCE OF CHLORINE (Cl) GAS IN AN URBAN HOSPITAL MEDICAL AIR SYSTEM
Jeffrey P. Natterman MA, RRT, Joseph
G. Dwyer BS, RRT. The Johns Hopkins Hospital, Baltimore Maryland.
Introduction: During routine repair
and maintenance of clinical equipment, discoloration of bronze
filters from air inlet ports revealed sintered material suggesting
possible contamination through the hospital medical air system.
Chemical analysis by an Applied Physics Lab resulted in the presence
of Chlorine bound to the copper in bronze. Chlorine is a known
respiratory irritant in concentrations as low as 3 ppm, therefore the
following procedure was implemented to detect, measure and assess the
impact of chlorine in the hospital medical air system. The process
for comparing levels based on differing seasons was a result of more
frequent clinical equipment repairs being required following the
summer months.
Methods: Twenty (20) samples were
collected (10 in January, 10 in July) in four (4) liter (L) Teldar
bags equipped with one-way valves. The samples were then passed
through Draeger graduated ten-stroke chlorine cuvettes (by means of
the Draeger calibrated hand pump) with the capacity to analyze the
presence of chlorine in concentrations from 0.2 – 3.0 ppm.
Absence of chlorine results in no color change from white in the
cuvettes, presence of chlorine results in a color change to
yellow/orange depending on the level of concentration.
Results:There was no detectable Chlorine
from any of the 10 samples measured during the winter months,
however, the summer month samples resulted in Chlorine levels ranging
from 0.2 ppm – 1.0 ppm with a mean value of .48 ppm.
Conclusions: The measurable
presence of Chlorine gas within the hospital medical air system is
concerning enough to evaluate potential exposures and outcomes from a
risk management standpoint. The low levels (and lack of Chlorine
during specific time frames) invite investigation to determine
source, seasonal activities and potential increases in future levels.
Urban medical facilities, especially those with aging medical air
systems frequently use water cooling mechanisms during air
compression before introducing the gas into the hospital lines.
Mechanical ventilators and air/oxygen blenders to deliver mixed gas
to the patient population then use the water-cooled air. During
summer months, especially during peak water usage, or drought
conditions, river water is occasionally used to supplement reservoir
use. The use of various water sources requires city water departments
to use higher levels of chlorine to maintain acceptable standards for
water purity. Continued monitoring and tracking for trends and spikes
in concentrations could result in more informed management of
systems, reduced cost for equipment repair and replacement, and above
all a more educated approach to patient care delivery.