Jr. Rudnick et al., GRAM-NEGATIVE BACTEREMIA IN OPEN-HEART-SURGERY PATIENTS TRACED TO PROBABLE TAP-WATER CONTAMINATION OF PRESSURE-MONITORING EQUIPMENT, Infection control and hospital epidemiology, 17(5), 1996, pp. 281-285
OBJECTIVE: To determine the cause(s) of an outbreak of gram-negative b
acteremia (GNB) in open-heart-surgery (OHS) patients at hospital A. DE
SIGN: Case-control and cohort studies and an environmental survey. RES
ULTS: Nine patients developed GNB with Enterobacter cloacae (6), Pseud
omonas aerugi;nosa (5), Klebsiella pneumoniae (3), Serratia marcescens
(2), or Klebsiella oxytoca (1) following OHS; five of nine patients h
ad polymicrobial bacteremia. When the GNB patients were compared with
randomly selected OHS patients, having had the first procedure of the
day (8 of 9 versus 12 of 27, P=.02), longer cardiopulmonary bypass (me
dian, 122 versus 83 minutes, P=.01) or cross-clamp times (median, 75 v
ersus 42 minutes, P=.008), intraoperative dopamine infusion (9 of 9 ve
rsus 15 of 27, P=.01), or exposure to scrub nurse 6 (6 of 9 versus 4 o
f 27, P=.001) were identified as risk factors. When stratified by leng
th of the procedure, only being the first procedure of the day and exp
osure to scrub nurse 6 remained significant. First procedures used pre
ssure-monitoring equipment that was assembled before surgery and left
open and uncovered overnight in the operating room, whereas other proc
edures used pressure-monitoring equipment assembled immediately before
the procedure. At night, operating rooms were cleaned by maintenance
personnel who used a disinfectant-water solution sprayed through a hos
e connected to an automatic diluting system. Observation of the use of
this hose documented that this solution could have contacted and ente
red uncovered pressure-monitoring equipment left in the operating room
. Water samples from the hose revealed no disinfectant, but grew P aer
uginosa. The outbreak was terminated by setting up pressure-monitoring
equipment immediately before the procedure and discontinuing use of t
he hose-disinfectant system. CONCLUSIONS: This outbreak most likely re
sulted from contamination of uncovered preassembled pressure-monitorin
g equipment by water from a malfunctioning spray disinfectant device.
Pressure-monitoring equipment should be assembled immediately before u
se and protected from possible environmental contamination (Infect Con
trol Hosp Epidemiol 1996;17:281-285).