Indian Journal of Medical Microbiology Medknow Publications on behalf of Indian Association of Medical Microbiology ISSN: 0255-0857 EISSN: 1998-3646 Vol. 29, Num. 2, 2011, pp. 169-171

Indian Journal of Medical Microbiology, Vol. 29, No. 2, April-June, 2011, pp. 169-171

Brief Communication

Central venous catheter-related blood stream infection rate in critical care units in a tertiary care, teaching hospital in Mumbai

K Chopdekar, C Chande, S Chavan, P Veer, V Wabale, K Vishwakarma, A Joshi

Department of Microbiology, Grant Medical College and Sir J.J. Hospital, Mumbai - 400 008, India

Correspondence Address:C Chande Department of Microbiology, Grant Medical College and Sir J.J. Hospital, Mumbai - 400 008 India cachande@gmail.com

Date of Submission: 09-Feb-2011
Date of Acceptance: 09-Apr-2011

Code Number: mb11039

PMID: 21654114

DOI: 10.4103/0255-0857.81796

Abstract

Keywords: Central venous catheter, blood stream infections

Introduction

Central venous catheter (CVC) is often used as a portal for the delivery of medications, parenteral nutrition, collection of blood samples and monitoring hemodynamic variables in critically ill patients. Noninfectious and infectious complications are frequently reported with central venous catheterization. ^[1] Blood stream infections related to central venous catheterization constitute one of the major nosocomial device associated infections. ^[1],[2],[3] For the surveillance of device-associated infections, the data needs to be expressed as the number of device-associated infections per 1000 device days as per the recommendations from the Center for Disease Control and Prevention, USA. ^[4] Very few published studies reporting rate of BSI related to CVC in pediatric and adult critical care units are available in the Indian literature. ^[1],[2]

Material and Methods

The study was conducted in a tertiary care hospital with 1400 bed capacity. The patients requiring CVCs admitted in adult intensive care units (Medical and Surgical, Bed size - 27), pediatric intensive care unit (bed size 14) and neonatal intensive care unit (bed size 40) during the study period (December 2008 to November 2009) were included in the study. Patient presenting with clinical symptoms and signs of septicemia after central venous catheterization were surveyed for blood stream infections. Data pertaining to age, sex, clinical diagnosis, site of insertion of CVC, treatment received, duration of CVC catheterization, duration of hospitalization and clinical outcome were recorded in each patient.

The catheter tip culture was done in all the patients at the time of removal of catheter. Semiquantitative method used by Maki et al. ^[5] was followed for catheter tip culture. Isolation of >15 CFU was taken as cut-off for positive tip culture.

Peripheral blood cultures were collected from the patients with clinical evidence of sepsis. For this 1 to 5 ml blood was collected under aseptic precautions in Hartley′s blood culture broth and cultures were processed by standard microbiological methods. ^[6] Bacterial isolates recovered from the blood cultures and corresponding tip cultures were subjected to antibiotic sensitivity testing as per CLSI 2009 guidelines. ^[7] CRBSI was defined as a positive blood culture obtained from a peripheral vein with clinical evidence of sepsis and with no apparent source of septicemia except tip and catheter tip colonization with same organism as in blood culture. ^[8]

Results and Discussio

During the study period, 85 CVCs were used in 78 patients in various critical care units who developed signs of septicemia during catheterization period. The maximum patients requiring CVCs were from pediatric ICU [Table - 1]. Eleven culture-proven blood stream infections occurred in 78 patients of which six were classified as CVC-related blood stream infections as per the definition. ^[8] The average CRBSI rate was 9.26 per 1000 catheter days ranging from 8.64 per 1000 catheter days in PICU to maximum rate of 27.02 per 1000 catheter days in NICU. In adult CCU, medical ICU has much lower CRBSI as compared to surgical ICU. CRBSI rate varies considerably in the different studies. ^[1],[2],[9] National nosocomial infection surveillance system of the Center for Disease Control and Prevention, Atlanta, USA, reports a CRBSI rate of 5.8 per 1000 catheter days. ^[4] As the patients receiving critical care were on the antibiotic treatment, the rate of CRBSI in the present study is likely to be influenced by this factor. Since most of the Indian data has not been expressed in terms of device utilization frequencies as the denominator, comparison with other studies in nosocomial infection surveillance becomes difficult. The two sites, femoral (74 catheters) and subclavian (11 catheters) employed for the placement of catheters showed CRBSI of 6.7% (5/74) and 9% (1/11), respectively. The site of insertion did not appear to influence the rate of CRBSI in this study. Femoral site has been reported to be the safest site by many workers. ^[1]

For interpretation of catheter tip colonization, criteria suggested by Maki et al. was used. ^[5] A total of 49 (57.6%) catheter tips were colonized with bacteria and fungi. The microbial pattern of catheter colonization revealed maximum colonization with Candida spp. all belonging to non-albicans type [Table - 2].

Catheter colonization did not appear to have direct bearing on blood stream infection (P-value 0.59, Fisher test, not significant). The predictive value of positive tip culture for diagnosis of CRBSI was found to be very low (0.1224). Hence antibiotic treatment based on the positive tip culture does not appear to be justified. No relation was observed by us with the duration of catheterization and CRBSI.

Coagulase-negative Staphylococci were the major (50%) cause of CRBSI followed by Klebsiella pneumoniae, Pseudomonas aeruginosa and non-albicans Candida spp. in one case each. All these four organisms are known to produce biofilms, which are reported to be universally present on CVCs. ^[10] All the bacterial isolates were multidrug-resistant showing resistant to more than two different classes of antibiotics. The antibiogram of these isolates also matched with the corresponding isolates from the catheter.

Mortality in CRBSI was observed in 33.3% cases compared to 20% mortality in cases of BSI in catheterized patients not related to CVC. CRBSI are reported to be associated with attributable mortality in the range of 10% to 25%. ^[9]

Since CVCs are increasingly being used in the critical care and have direct bearing on the mortality and morbidity and cost of treatment in the catheterized patients, regular surveillance needs to be undertaken for the formulation of appropriate infection control practices.

Acknowledgments

We thank Dr. Abhiram Kasbe, Associate Professor, Department of Preventive and Social Medicine from T.N. Medical College, B.Y.L.Ch. Hospital, Mumbai, for his help in providing statistical analysis of our data.

References

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