|Year : 2023 | Volume
| Issue : 1 | Page : 43-49
Evaluation of the incidence of central venous catheter-associated infections in patients admitted in the intensive care unit of a tertiary hospital in Nigeria
Onyekachi V Okafor1, Adaobi O Amucheazi2, Fidelis A Onyekwulu2
1 Department of Anaesthesia, University of Nigeria Teaching Hospital, Ituku/Ozalla, Enugu State, Nigeria
2 Department of Anaesthesia, College of Medicine, University of Nigeria, Ituku/Ozalla Campus, University of Nigeria Teaching Hospital, Ituku/Ozalla, Enugu State, Nigeria
|Date of Submission||08-Mar-2022|
|Date of Decision||27-Jun-2022|
|Date of Acceptance||05-Oct-2022|
|Date of Web Publication||13-Dec-2022|
Adaobi O Amucheazi
Department of Anaesthesia, College of Medicine, University of Nigeria, Ituku/Ozalla Campus, University of Nigeria Teaching Hospital, Ituku/Ozalla, Enugu State
Source of Support: None, Conflict of Interest: None
Background: Presence of a central venous catheter (CVC) though useful may lead to CVC-associated bloodstream infections (CVCBSIs), resulting in increased morbidity and mortality. Objectives: The objectives of the study were to determine the incidence of CVCBSIs, the predominant causative microorganisms, the antibiotic sensitivity pattern of the microorganisms, and the associated risk factors. Materials and Methods: This prospective observational study evaluated the incidence of CVCBSIs in patients who had the catheter inserted on admission into the intensive care unit (ICU) of a tertiary hospital in South-East, Nigeria. Sixty-eight patients were recruited for the study. Blood samples were collected aseptically from a peripheral vein on admission, 72 h after the insertion of CVC, and at removal of CVC for blood culture. The distal 5 cm of the CVC was also collected at removal for microscopy, culture, and sensitivity testing. Results: Six out of all the patients recruited developed CVCBSIs, giving an incidence rate of 9.2%, whereas 48% (n = 31) developed catheter bacterial colonization. Over one-fifth (22.7%) of the patients with catheter duration beyond 5 days had CVCBSIs. Patients whose CVC duration was beyond 5 days had a higher risk of CVCBSIs (P = 0.015) than others. The commonest microorganism isolated was Staphylococcus aureus, whereas the most susceptible antibiotic was aminoglycoside (gentamycin). Conclusion: The incidences of CVCBSIs and CVC colonization were 9.2% and 48%, respectively. The duration of catheterization was found to be a major risk factor for CVCBSIs. The most predominant organism isolated was S. aureus. The most sensitive antibiotic agent was the aminoglycoside (gentamycin). It is therefore recommended that catheter care bundle which includes hand hygiene, use of chlorhexidine for skin preparation during insertion, use of barrier precautions during insertion, and the removal of unnecessary central lines should be strictly adhered to. Gentamycin should be used as empirical antibiotics in the ICUs.
Keywords: Blood, central venous catheter, infection, pathogen
|How to cite this article:|
Okafor OV, Amucheazi AO, Onyekwulu FA. Evaluation of the incidence of central venous catheter-associated infections in patients admitted in the intensive care unit of a tertiary hospital in Nigeria. Int J Med Health Dev 2023;28:43-9
|How to cite this URL:|
Okafor OV, Amucheazi AO, Onyekwulu FA. Evaluation of the incidence of central venous catheter-associated infections in patients admitted in the intensive care unit of a tertiary hospital in Nigeria. Int J Med Health Dev [serial online] 2023 [cited 2023 Mar 30];28:43-9. Available from: https://www.ijmhdev.com/text.asp?2023/28/1/43/363247
| Introduction|| |
Central venous catheter (CVC) is an integral component of patient care in the intensive care unit (ICU). Unfortunately, infection is a leading complication of CVC insertion., Risk factors include less stringent barrier precautions during placement, inexperienced personnel, long duration, and site of the catheter. The incidence is reported to be 3–8%. The resulting infection may worsen morbidity and increase mortality and healthcare costs. These are undesirable especially in resource-poor countries in which funding for medical bills is out-of-pocket payment. This study will help in understanding the burden of CVC-associated infections and identifying risk factors, leading to a modification of practice. The objectives of this study therefore were to determine the incidence of CVC-associated bloodstream infections (CVCBSIs), the predominant causative microorganisms, the antibiotic sensitivity pattern of the microorganisms, and the associated risk factors.
| Materials and Methods|| |
Ethical clearance for this study was obtained from the Research and Ethics Committee of the University of Nigeria Teaching Hospital (UNTH), Ituku-Ozalla, Enugu (UNTH/CSA/329/OL.5:NHREC/05/01/2008B-FWA00002458-1RB00002323). All the guidelines outlined in the Declaration of Helsinki were met and a written informed consent from each patient or caregiver was obtained. This prospective observational study was conducted on patients admitted to the ICU of the University of Nigeria Teaching Hospital (UNTH), Ituku-Ozalla, Enugu State, Nigeria. The inclusion criteria were adult patients (18 years and above) who had CVC inserted in the ICU and normal full blood count on admission. Patients were excluded if they were less than 18 years, had white blood cell count on admission of < 4 × 109/L or >12 × 109/L, platelet count ≤ 50,000, or had features of sepsis prior to ICU admission [temperature >38oC or <36oC, heart rate >90 beats/min, respiratory rate >20 breaths/min, low blood pressure (systolic blood pressure <90 mmHg), persistently low urine output (< 20 mL/h)]. They were also excluded if the stay in the ICU is anticipated to be brief (<72 h) (the CVC is usually removed before discharge and the literature suggests that duration greater than 72 h is a risk factor for infection) or had burns or infection over the site of proposed vascular puncture. The study was conducted over 14 months. The sample size was calculated using the formula for determining the minimum sample size for the prevalence rate of a condition in a population, assuming a confidence level of 95%, a power of 80%, and a degree of accuracy of 0.05. The sample size was calculated to be 68. Attrition was factored in. Each patient was connected to a standard monitor (GE Solar 8000m Multiparameter Monitor) and vital signs documented. The CVCs were inserted following strict asepsis by one researcher using a size 7.5fr triple lumen CVC set (ARROW International USA) using the right internal jugular vein. The date of insertion was noted. Following the standard procedure, the dressing, stopcocks, and injection membrane were aseptically changed every third day. Each site was cleaned with chlorhexidine/70% alcohol solution. Systemic antibiotics were given through peripheral line. The vital signs were monitored and the highest and lowest values recorded daily. The patients were checked daily for signs of inflammation which include swelling, pain, erythema, warmth, and exudates at the site of insertion. A positive sign of inflammation was managed by removing the catheter, taking a swab for microscopy culture and sensitivity, cleaning the site with an antiseptic solution, and application of sterile dressing. The CVC was aseptically removed when no longer needed or there was inflammation/malfunction. Early removal was defined as catheter removed before 5 days and late removal as catheter removed after 5 days of insertion (standard for the indication for insertion). On removal, the distal 5 cm of the CVC tip was cut off, placed in a sterile container, and immediately transported to the laboratory. The sample was cultured within 30 min of collection by a microbiologist. Samples were stored at 4–6°C. Line culture was based on the Maki Semi Quantitative Roll Technique. The catheter tip was rolled onto 5% blood agar and MacConkey plates using sterile forceps. Colony counts were performed after overnight incubation in 5% carbon dioxide (CO2) at 37°C. Plates with no apparent growth were re-examined at 48 and 72 h following further incubation. Result was recorded as positive if colony counts were > 15 CFU and negative for either no growth or <15 colonies. Blood was collected aseptically from a peripheral vein at the time of insertion of CVC, after 72 h, and at removal of CVC for full blood count. Also 10 mL of blood was collected aseptically and injected in a blood culture medium (oxide medium capable of growing both aerobic and anaerobic organisms) at 72 h and at the time of removal of CVC line for blood culture. The sample in the oxide medium was incubated for up to 6 days using an automated blood culture system, and bacterial isolates were identified using standard methods. Sensitivity testing was carried out on all isolates using a wide range of antibiotics including gentamycin, imipenem, perfloxacin, clindamycin, and so on.
Other information collected were demographic data, diagnosis, date of admission, as well as the presence of other invasive devices such as tracheal tube, chest tube, and urinary catheter. Antibiotic therapy was also documented. Data were collected on forms specifically designed for the study. Statistical analysis was performed using Statistical Package for Social Sciences (SPSS), version 17. Data were presented in tables and figures expressed as mean (±SD). Statistical association was determined using the χ2 test for categorical variables (sex and diagnosis). A P-value of less than 0.05 was considered significant.
| Results|| |
Sixty-eight patients were recruited but 65 patients completed the study. Three patients were dropped because their catheters were removed without prior information to the researcher. The age range of patients was 19–70 years with a mean age of 40.32 years and standard deviation ± 11.49%. The age range (31–40 years) was the most frequent age group [Table 1].
The incidence of CVC colonization was 31 (48%). Six (9%) of all the patients recruited developed CVCBSIs. CVCBSIs developed in 1 (2.3%) patient when the catheter was removed within 5 days of insertion. Of the catheters that were kept for longer than 5 days, 5 (22.7%) patients developed CVCBSIs. Subjects with late removal of CVC were more likely to have BSIs than those that were earlier removed (Fisher’s exact significance = 0.015) [Table 2]. Furthermore, no statistically significant association was found between the presence of tracheal tube, urinary catheter, chest tube, and BSIs [Table 2].
|Table 2: Duration of catheterization with other invasive devices vs. CVCBSIs|
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The CVCs were placed in 21 (32.3%) patients for both drug administration and blood transfusion. In 14 (21.5%) patients, it was used for both drug administration and CVP monitoring. The rest 14 (21.5%) patients had CVC placed for blood transfusion alone [Table 3]. Considering the indication for CVC placement and subsequent development of CVCBSIs, the following resulted: for the blood transfusion and drug administration subgroup, 4 (19.0%) developed CVCBSIs. While in the blood transfusion subgroup, 1 patient (7.1%) developed CVCBSIs (χ2 = 115.271, P = 0.018). While for the fluid and drug administration subgroup, the only patient there developed CVCBSIs [Table 4].
The bacterial isolates from the catheters with a positive tip isolate were mainly Staphylococcus aureus 11 (16.9%), Escherichia coli 4 (6.2%), Peptostreptococcus 1 (10.5%), and Enterobacter spp. 1 (1.5%). Blood culture was positive in six patients and the same organisms also isolated in their catheter tip [Table 5].
Seventy-two (72) hours after insertion of the catheter, blood culture revealed the growth of S. aureus 3 (4.6%), E. coli 2 (3.1%), and Salmonella typhi 1 (1.5%). The same organisms were cultured at the removal of CVC line at the same frequency [Table 6].
[Table 7] shows the antibiotic sensitivity pattern of all the bacterial isolates. Most of the isolates were highly sensitive to gentamycin: 26 (70.3%) of 37 organisms, whereas 19 (51.4%) of the isolates were sensitive to imipenem. This was followed by floxacine 15 (40%).
The study also showed that Pseudomonas and Enterobacter spp. are 100% highly sensitive to imipenem, whereas Pseudomonas alone is 100% moderately sensitive to floxacin. Peptostreptococus had the highest sensitively to cotrimoxazole alone. The bacterial isolates from catheter tip and blood culture had similar antibiotic sensitivity pattern.
[Table 8] shows the antibiotic resistance of isolated bacteria. Klebsiella, Pseudomonas, and Enterobacter were all 100% resistant to ceftriaxone, augmentin, nitrofurantoin, and clarithromycin, whereas Enterobacter was all 100% resistant to all the antimicrobials tested. Pseudomonas and Enterobacter are both 100% resistant to gentamycin. Thirty (81.1%) of the 37 bacteria isolated were resistant to ceftriaxone, whereas 23 (62.2%) were resistant to augmentin. S. aureus showed various resistant patterns to all the antimicrobial agents used in this study but resistance to gentamycin was insignificant 1 (7.1%).
[Table 9] shows the results of full blood counts at insertion of VC line of all 65 patients studied. The mean white blood cell (WBC) at insertion was 7.03 ± 1.45, hemoglobin 10.19 ± 1.19, and platelet was 178.06 ± 44.84. Seventy-two hours after insertion, the mean WBC was 8.64 ± 2.19, hemoglobin 9.95 ± 1.04, and mean platelet was 173.60 ± 42.44. At the removal of CVC line, the mean WBC was 8.72 ± 2.43, mean hemoglobin 9.64 ± 1.07, and mean platelet was 171.88 ± 39.68.
All the patients studied were on antibiotic therapy during the course of the study. The main antibiotic regimen was first-generation cephalosporin with metronidazole in 33 (50.8%) patients, followed by third-generation cephalosporin with metronidazole in 8 (12.3%) patients. Imipenem and metronidazole were used in 4 (6.2%) patients.
In patients who developed CVCBSIs, temperature was initially normal on the first and second days following insertion of the catheter but began to increase 72 h later and peaked to 39–40°C on the 10th day. Pulse had a similar response, whereas respiratory rate (RR) and oxygen saturation (SpO2) were simultaneously linear. Mean arterial pressure progressively decreased from the third day following insertion of CVC line.
| Discussion|| |
This study has shown that the incidence of CVC colonization and catheter-related bloodstream infections (CRBSIs) was 48% and 9%, respectively. According to the National nosocomial infectious surveillance system report, 1–13% of CVC insertions lead to CVCBSI and the incidence density ranges from 2 to 4.5/1000 catheter day., The incidence in this study is much higher than this rate in a study by Vassiliki et al. Their results showed that the incidence of colonization and CRBSI was at the internal jugular vein 7.34 and 3.73, respectively. They observed high colonization rate with the femoral site and lower rates with the internal jugular route. Another study by Maria-Jesus et al. also revealed a lower incidence of colonization (18.3%) compared with our study. Abirami et al. in a study found incidence of 20.75% and 17.6% for CVC colonization and CRBSI, respectively. These figures were lower than what we obtained in the study. The difference could have been in the number of attempts and environmental factors.
Duration of catheterization was the only risk factor in this study, which was statistically significant. Among the 6 patients who developed CVCBSIs, 5 (22.7%) had their catheters removed beyond 5 days of insertion (late removal). In a study by Cheng et al. in patients for renal replacement therapy, they observed that longer duration of catheter was associated with BSIs. This is similar to our findings. However, in a study by Vassiliki et al., the finding was at variance with our study: the duration of catheter stay did not contribute to BSI.
Gram-positive S. aureus was the most common pathogen for CVCBSIs followed by E. coli and S. typhi, whereas for catheter colonization, Staphylococcus also was the most common followed by Klebsiella. Our finding differs from that of Vassiliki et al. Their study showed a prevalence of Gram-negative organisms. The commonest pathogen in their study was Acinetobacter baumanii. However, other authors showed similar pathogens as found in this present study. In a study by Cheng et al. in patients on renal replacement therapy, they found Gram-positives, especially S. aureus as the common pathogen. So did Weiner et al. and Lin et al., Most studies carried out to identify the colonized and infecting organism have documented that the microorganism implied in CVC-BSI are part of normal skin microorganisms. Gram-positive Cocci are responsible for at least two-thirds of these infections with predominance of Staphylococcus. The change in the pattern of pathogens causing CVC colonization and CVCBSIs may reflect the differences in the resident flora as well as alteration in the epidemiology of bacteria among population, geographical regions, and different institutions. The isolation of S. aureus in large numbers from CVCBSIs probably suggests the colonization by the skin flora of the patient or medical personnel as the origin of infection. It is also an indication of poor catheter care protocol.
A total of 19 antibiotics belonging to different classes were tested in this study against 37 bacterial pathogens. Gentamycin had the highest sensitivity of 70.3%. This is similar to the findings of Salau et al. in Zaria, Kaduna State where most of the bacterial isolates showed 100% susceptibility to gentamycin among other antibiotics. This implies that gentamycin would be effective for empirical antibiotics therapy in our locality. Aminoglycosides still play an important role in anti-Staphylococcus therapies, although emerging resistance among Staphylococcus is widespread.
The limitations of this study include the use of full blood count, resulting in the initial recruitment to determine patients without infection. Also all patients were on antibiotics and this might have affected the results of this study.
In conclusion, the incidence of CVCBSIs and CVC colonization was 9% and 48%, respectively. Duration of catheterization was found to be a major risk factor for CVCBSIs. The most predominant organism isolated was S. aureus. The most sensitive antibiotic agent was the aminoglycoside (gentamycin). It is therefore recommended that catheter care bundle which includes hand hygiene, use of chlorhexidine for skin preparation during insertion, use of barrier precautions during insertion, and the removal of unnecessary central lines should be strictly adhered to. Gentamycin should be used as empirical antibiotics in the ICUs.
We owe a debt of gratitude to our research assistants.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
Literature search: OVO;
Manuscript drafting/revision: OVO, AOA, FAO;
Final Approval: OVO, AOA, FAO.
This original article is the edited version of the Part 2 dissertation submitted to the National Postgraduate Medical College, Nigeria.
This manuscript has been read and approved by all the authors. The requirements for authorship have been met by the authors and the manuscript represents honest work by the authors.
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[Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6], [Table 7], [Table 8], [Table 9]