NTRAVENOUS LINE TIP CULTURES AND BACTERAEMIA IN THE INTENSIVE CARE UNIT OF THE UNIVERSITY COLLEGE HOSPITAL, IBADAN

Abstract

Patients in the intensive care unit (ICU) often require the insertion of various
invasive devices such as peripheral venous lines, urinary catheters and tracheal tubes
for monitoring and or therapy. These devices predispose them to a high risk of acquiring
nosocomial infection.
The aim of this prospective study was to determine the microbial pattern and
antibiotic sensitivity of agents causing colonization of intravenous (IV) line and
bacteraemia in ICU patients.
This prospective observational study was conducted in the ICU of the University
College Hospital (UCH) Ibadan, which is a 5-bedded unit. All patients admitted into the
ICU over a 4-month period, from June to September 2004 were included in the study.
Intravenous lines once discontinued had their tips cut using a non-touch
technique. Line tip culture was based on the Maki semi-quantitative roll technique. The
tip was rolled onto 5% Blood agar and MacConkey plates using sterile forceps. Colony
counts was performed after overnight incubation in 5% carbon dioxide (CO2 ) at 37o C.
Plates with no apparent growth were re-examined at 48 hours and 72 hours following
further incubation. Results were recorded as positive if colony counts were more than
15; and negative for either no growth or less than 15 colonies. Following skin
preparation with 70% alcohol, 5 ml of venous blood was withdrawn aseptically from all
patients at a site different from the site of intravenous access, for culture on days one,
two and three. Aerobic and anaerobic blood culture sets were incubated and bacterial
isolates were identified using standard methods.
A hundred and twenty-one patients admitted during the study period had 242
peripheral intravenous lines. No central line was inserted during the study period.
Seventy-three (60.3%) patients had two lines and the most frequent site of insertion was
the dorsum of the left hand which accounted for 51 (21.1%) of the lines. Of the 242
peripheral intravenous lines, 175 were discontinued and removed. One hundred and
seventy four of these discontinued peripheral lines were processed. Sixty-five (37.4%)
of these processed lines, from 50 patients had bacterial growth, with some patients
having growth from more than one line. The bacterial isolates were Staphylococcus
aureus 23 (35.4%), Klebsiella 17 (26.1%), Pseudomonas 13 (20%), coagulase negative
Staphylococcus 7 (10.8%) and mixed growth 5 (7.7%). Among the 121 patients, blood
culture was positive in four patients and the same organism (Staphylococcus aureus)
was isolated from the catheter tip and blood in two and coagulase negative
staphylococcus and Klebsiella were isolated from the other two patients. The other
invasive devices inserted in these patients were urinary catheters in 108 patients
(89.26%), tracheal tubes in 64 patients (52.89%), nasogastric tubes in 47 patients
(38.84%), wound drains in 13 patients (10.74%) and chest tubes in 8 patients (6.61%).
This study revealed that bacterial colonisation of peripheral intravenous lines was
common in patients admitted into the ICU.
Institution of guidelines for placement and management of intravascular access
is desirable. The lines should be inspected daily and dressed as appropriate. Lines no
longer in use should be removed and the site dressed. The site of intravenous cannulae
and fluid administration sets should be changed every 48 – 72 hours.