|Year : 2017 | Volume
| Issue : 2 | Page : 78-82
Central line-associated bloodstream infection: A study on creating awareness about specimen collection
Kavita Raja, Gracyamma Bridget
Infection Control Nurse, Hospital Infection Control Unit, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, Kerala, India
|Date of Web Publication||19-Jan-2018|
Dr. Kavita Raja
Professor of Microbiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum - 695 011, Kerala
Source of Support: None, Conflict of Interest: None
Background: Central line associated Blood stream infection(CLA-BSI) is a hospital acquired infection that is often missed. In a patient on a central line, culture of peripheral blood along with a sample of blood taken through the CL or CL tips is imperative, for a better laboratory diagnosis of CLA-BSI.
Aim: (1) To compare the number of CLA- BSI detected in 2010 with the number in 2012 after the awareness campaign was conducted in 2011. (2) To compare specimen collection in different units and formulate strategies for improvement.
Methods: Using the laboratory information network, the number of cannula tips and blood cultures sent for culture in 2010 was taken. An intensive campaign to detect CLA-BSI, was initiated in 2011 by the Infection Control Team. The total number of CLA-BSI detected in 2010 was then compared with the number in 2012 after this campaign.
Results: A total of 158 cannula tips were sent for culture during the year 2010, while in 2012, 276 cannula tips were sampled. In 2010, while incomplete sampling occurred in 39%, this was reduced to 33% in 2012. Number of correctly diagnosed CLA-BSI increased from 13 to 27 cases in 2012.
Conclusion: The campaign has led to detection of more correctly defined CLA-BSI and hence, continuing the training in sending samples is essential to collect the correct data of CLA-BSI. The case studies included show the benefits of correctly identifying such infections.
Keywords: CLA-BSI, Methods of collection, Specimen
|How to cite this article:|
Raja K, Bridget G. Central line-associated bloodstream infection: A study on creating awareness about specimen collection. J Patient Saf Infect Control 2017;5:78-82
|How to cite this URL:|
Raja K, Bridget G. Central line-associated bloodstream infection: A study on creating awareness about specimen collection. J Patient Saf Infect Control [serial online] 2017 [cited 2018 Sep 20];5:78-82. Available from: http://www.jpsiconline.com/text.asp?2017/5/2/78/223695
| Introduction|| |
Central line-associated bloodstream infection (CLA-BSI) is a hospital-acquired infection that is often missed. In cases of fever of unknown origin in a patient on a CL, culture of peripheral blood along with a sample of blood taken through the cannula or cannula tips is imperative, for a better laboratory diagnosis of CLA-BSI. Increasing awareness and thereby improving detection reduces morbidity and mortality.
Sampling pattern adopted by different units for diagnosing CLA-BSI will give an idea about the kind of intervention needed in that unit to improve awareness and sampling efficiency.
The aim of this study is to compare the specimen collection for CLA-BSI diagnosis between 2 years, 2010 and 2012, after a campaign for proper specimen collection was initiated in 2011.
(1) To compare the number of properly diagnosed CLA-BSI in 2010 with the number in 2012 after the campaign was started in 2011. (2) To compare specimen collection techniques for detection of CLA-BSI in different units and formulate strategies for improvement.
| Materials and Methods|| |
Sree Chithra Tirunal Institute for Medical Sciences and Technology (SCTIMST) is a 254 bedded tertiary level referral institute under the Government of India that has 4 broad specialities, namely cardiology, neurology, cardiovascular and thoracic surgery (CVTS) and neurosurgery. There is a separate paediatric (congenital heart) surgery unit for children. There are seven Intensive Care Units (ICUs) with 70 beds where patients are admitted after undergoing very complicated procedures. Hence, they have to be on different life support systems such as ventilators, multiple CL s, urinary catheters and different kinds of monitors for prolonged periods.
The different intravascular devices used here are:
- Single lumen central venous catheter (CVC)
- Triple lumen CVC
- Double lumen CVC - FG14 (for plasmapheresis)
- Peripherally inserted central catheter.
In 2011, according to the National Healthcare Safety Network (NHSN), definition of CLA-BSI is: A laboratory-confirmed bloodstream infection (LCBI) where a CL was in place for >2 calendar days when all elements of the LCBI infection criterion were first present together, with day of device placement being day 1, and a CL was in place on the date of the event or the day before. If the patient is admitted or transferred into a facility with a CL in place (e.g., tunnelled or implanted central line), day of first access is considered day 1.
There should be no site-specific specimen culture positive, only a positive blood culture.
In this study, a CLA-BSI was diagnosed in the laboratory as per the above definition and only when the same isolate was obtained from both CL tip and blood culture. The same isolate means the same species and same antimicrobial susceptibility pattern in the case of bacterial isolates. No typing was done for any of the isolates.
CL tips are removed and sent when there is an unexplained fever, and hence that day was taken as the day of the sentinel event. Blood samples taken within 5 days before within 5 days after the CL tip was removed, were included as proper sample collection. This was before the new NHSN guidelines mandating blood drawn through the line was issued in 2013.
Counts of CL tips taken alone (wrong specimen collection) and the number of discrepant isolates if both were taken, were also recorded. The total number of each such category in 2010 was compared with the number of each category in 2012 after the start of this campaign. The categories were as follows:
- Positive for CLA-BSI (as per definition)
- Negative for CLA-BSI
- Indeterminate, i.e., different organism from the two samples
- Cannula tip alone.
Using the laboratory information network, the total number of cannula tips received in the Microbiology laboratory in 2010 and 2012, was counted. Percentages were calculated for all above categories using this total number as the denominator. There was no provision to calculate CL days at that time.
The different isolates and their number in each year were noted.
In the year 2010, there was no specific programme to detect CLA-BSI. An intensive campaign was initiated in 2011 by the infection control team.
- Training for link nurses who were the nurses who report to the infection control nurse (ICN) from each ward
- Follow-up of each CL tip that was sent, especially those without simultaneous blood culture
- Encouraging sampling of CL tips and blood culture when there is fever without any obvious site of infection.
Data were entered into MS EXCEL, rates calculated for each unit in 2010 and 2012 for comparison and charts prepared using EXCEL.
A few case histories where morbidity was reduced by the correct recognition of the infection due to proper sample collection, during this campaign are also described.
| Results|| |
A total of 158 CL tips were sent for culture during the year 2010 while in 2012, 276 CL tips were received at the microbiology laboratory. To prevent dilution of the overall outcome, the CL tips sent by the CVTS unit were excluded from the analysis as they had a protocol of sending the CL tips of all the prosthetic valve patients at the time of discharge without any obvious signs of infection or fever. No blood culture is sent with these samples. In 2010, the number was 398 and in 2012, it was 415.
[Table 1] shows the numbers for each category (1, 2, 3 and 4 described above) for 2010 and 2012. Unit-wise rate of positive CLA-BSI according to the definition is given as percentage of total CL tips, in [Figure 1] and [Figure 2] comparing the performance of the different units in 2010 and 2012. [Figure 5] shows the prevalence of different organisms. In 2010, non-albicans Candida was the most common while in 2012 Klebsiella was the most common isolate. Pseudomonas was the second highest in both the years.
|Figure 1: Number of proved central line associated blood stream infection per total CL tips as percentage, in different units in 2010|
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|Figure 2: Number of proved central line associated blood stream infection per total CL tips as percentage in different units in 2012|
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Proper diagnosis of CLA-BSI is shown in [Figure 1]and 2 with the proportion contributed by each unit. Neurology has contributed to 48% of the total correctly diagnosed CLA-BSI in 2012. While 38% was the contribution of paediatric surgery in 2010, it was CVTS that contributed 30% in 2012.
In the following [Figure 3], [Figure 4], [Figure 5], [Figure 6] comparing the proper sample collection performance of the different units in 2010 and 2012, unit-wise data are given as a percentage of the total CL tips sent from that unit. In the pie charts shown below, the entire sector including positive, negative and indeterminate are the ones representing correct specimen collection. The blood not sent sector of the pie chart represents incorrect specimen collection (violet colour). The size of the violet sectorin 2010 and 2012 can be easily compared in the pie charts.
|Figure 3: Comparison of proved CLA-BSI in Neurology unit in 2010 and 2012|
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|Figure 4: Comparison of proved CLA-BSI in Neurosurgery unit in 2010 and 2012|
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|Figure 6: Comparison of proved CLA-BSI in Paediatric Surgery unit in 2010 and 2012|
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[Figure 7] shows the prevalence of different organisms. In 2010, Candida spp, (albicans and non-albicans) was the most common while in 2012, Klebsiella spp was the most common isolate. Pseudomonas aeruginosa was the second highest in both the years.
| Discussion|| |
This study has the primary aim of promoting the proper collection of specimen for a correct diagnosis of CLA-BSI. Hence, any increase does not mean that there was an increased rate in the corresponding year. It only means that more CLA-BSI have been identified. A similar concept is described in the article on arterial catheters (AC) where the authors say that ACs are neglected while taking samples to diagnose CLA-BSI, though they are also responsible for CLA-BSI. Very few articles could be found in the literature that looked into improving sample collection to improve detection of CLA-BSI.
From the results, comparing the violet coloured sectors in the pie charts between 2010 and 2012 for each unit, it can be seen that:
- Neurology unit has adhered to the diagnostic criteria and this unit with a lot of chronic patients in the ICU has managed to detect more BSIs accurately
- Neurosurgery unit has shown the least response to the campaign with only a small change in the accurate diagnosis of CLA-BSI
- CVTS unit has a protocol for sending cannula tips without any blood cultures as a matter of routine for all patients with prosthetic valves. This concept was challenged, and change is noticed where blood culture is sent if the patient has a fever or a CL tip is positive by culture
- Paediatric surgery where infants and neonates undergo open heart surgery has also diagnosed more BSIs, but extensive sampling has led to more of indeterminate results
- The cardiology unit uses very few central lines, and hence though the study was done, no comparison could be made.
In confirmed or suspected CLA-BSI, management is multi-faceted and encompasses the selection of an empiric antibiotic, the determination of whether the infected catheter should be removed and the narrowing of antibiotic spectrum once a pathogen has been isolated. In 2010, the most common cause for CLA-BSI was Candida spp. In 2012 probably due to improved diagnostic approaches, the most common organism was Klebsiella spp. This is in contrast to the Western literature where Gram positives and Candida spp. are more common.
In this centre, in 2010 a need for better diagnosis of CLA-BSI was felt, but it came up as a campaign only in 2011. Only after proper specimen collection is achieved can data on CLA-BSI can be generated and used to monitor efforts to reduce them.
As the awareness grew, more and more cases came up, and patients with unexpected fevers were quickly taken off catheters. As an example of the impact this kind of campaign has on individual patient management, four instances are described here, where lives could be saved due to the insistence for correct microbiological specimen collection.
A case of post-operative complications following surgery for intra-cranial aneurysm
A 52-year-old female, who underwent emergency surgery for clipping of the intra-cranial aneurysm, had a prolonged stay in the Neurosurgery ICU. She was on mechanical ventilation for 1 ½ months. On 1/12/12, she was off the ventilator and moved out of the ICU. However, on 4/12/12, she suddenly developed high-grade fever. Blood culture grew Elizabethkingia meningosepticum, but cerebrospinal fluid (CSF) was sterile, and there were minimal respiratory secretions. On advice from the ICN, the remaining triple lumen subclavian line was removed, and the tip sent for culture. The same organism was recovered from the cannula tip. Fever remitted as soon as the CL was removed. She was treated with vancomycin for 7 days.
A case of infective endocarditis
Female 16 years, was diagnosed with infective endocarditis (IE) of the Mitral valve with vegetations. Blood culture grew Streptococcus mitis resistant to Gentamicin (high-level aminoglycoside resistance). Since the organism was sensitive to Penicillin and Streptomycin, she was started on that combination. Although she became afebrile, the vegetations embolised and she had to undergo intracranial mycotic aneurysm removal and right renal artery aneurysm coiling. After these procedures, the renal arterial line was in situ. She developed a fever after the renal artery surgery that persisted until the renal arterial line was removed. This was mistaken for recurrence of IE until the ICN advised removal of the arterial line and the fever remitted. There was no growth on blood culture, and the line was not sent for culture. Although sample collection was incomplete, the remittance of fever is an indication that it was the cause for the fever.,
A case of viral encephalitis
Female, 26 years, developed high-grade fever and loss of consciousness 4 months after delivery. In the Neurology ICU, she was treated with a ventilator and multiple lines for supportive therapy. During her stay in the ICU, the fever was controlled until it suddenly went up to 104°F. Blood cultures were taken and again on advice from ICN 3 different central lines were removed and tips sent for culture. The blood and the triple lumen tip grew E. meningosepticum. Her general condition improved after fresh lines were put. She was started on Vancomycin, but the fever maintained at 100°F, as the encephalitis was persisting.
A case of post-traumatic seizures and meningitis following intracranial device insertion
Male 23 years, was admitted with meningitis and CSF grew Klebsiella sensitive to Chloramphenicol and Gentamicin. He recovered after treatment with intrathecal Gentamicin. However, on the day of transfer to the ward from the ICU, he developed high-grade fever. Recurrence of meningitis was suspected and CSF culture repeated. On advice from the ICN, his blood and the CL tip were sent for culture. Blood was sterile, but the CL tip grew Klebsiella pneumoniae with a different sensitivity pattern from the CSF isolate. His fever remitted at once, and he did not need any specific treatment other than line removal.
From these case histories, it is evident that CL infection can present in different ways. The fever can be mistaken for the failure of antibiotic treatment of the original condition such as meningitis or IE. CL removal caused remission of the fever, but in some cases, antibiotic treatment was also necessary.
| Conclusions|| |
The numbers involved were too low for statistical analysis. Hence, a significant improvement could not be established between 2010 and 2012. In the different units, different strategies are needed to improve specimen collection:
- CVTS: Continuing awareness programmmes for better diagnosis of CLABSIs by proper sample collection of both blood culture and central lines on the same day, only in cases of fever
- Paediatric surgery: Concentrating on getting better and less contaminated blood samples and trying to salvage the catheters
- Dissemination of data to all units, which can help in preventive measures being taken up seriously.
- Scientific and Technical staff of the Department of Microbiology, SCTIMST, for the proper identification of the isolates
- Nursing and other clinical staff of the units for cooperating with the study.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
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Clinical practice guidelines for the diagnosis and management of intravascular catheter-related infection: 2009 Update by the Infectious Diseases Society of America. Clin Infect Dis 2009;49:1-45.
[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6], [Figure 7]