Central Line-Related Bloodstream Infections and Microbiological Study

Table of Contents

Introduction Central Venous Catheter is utilized to administer parentral fluids or high alert medication , obtain venous samples and measure central venous pressure in critically ill patients. (1). Insertion of CV catheters have been associated with many hazards. The most frequent hazard is blood-stream infections (BSIs) (2). The risk factors of catheter-related blood-stream infections (CRBSIs) have been categorized into catheter-related factors, patient-related factors and technical related factors. (3). Thus, Critical care nurses can manage and control these factors by applying the strict aseptic techniques and following the CDC evidence-based guidelines(4,5). . Gram-negative bacilli and gram-positive cocci are responsible for a higher proportion of catheter-related infections in the critical care units(CCUs) than other health care settings. (6). Biofilm formation has not only been considered as a key factor in a venous catheter-related infection but also include resistance to antibiotic administration. (7). The compliance to preventive measures and maximal barrier precautions such as the use of antimicrobial-coated catheters during catheter insertion have been verified to reduce the spread of blood stream infection. (4) And health care costs (8). Owing to insufficient data related to central venous catheter bloodstream infection originated from critical care settings in our country, this study was conducted in one critical care unit at a ministry of health hospital to determine the incidence, risk factors, microbes and investigates the antimicrobial susceptibility and resistance by CVC-BSI isolates.Research questions:The following research questions were stated:1-what is the incidence rate of CLABSI among the studied ICU patients?2- What are the predisposing factors to CLABSI among the studied ICU patients?3-what are the microorganisms responsible for the incidence of to CLABSI among the studied ICU patients?4- What are the patterns of antibiotic sensitivity of the separated bacteria in critically ill patients?2-Subjects and methods2.1. Design: a descriptive exploratory design was employed. Consecutive critically ill patients were engaged into the study between September 2015 and September 20162.2. SettingThe study was conducted at a medical critical care unit at a ministry of health hospital in Egypt. 2.3. Sample A purposive sample of 120 adult patients admitted to the critical care unit and underwent insertion of central venous catheters were recruited. The inclusion criteria involved patients who showed negative blood culture before insertion of central venous catheters. 2.4. Methods- Patients’ demographic and clinical data: such as age, gender, body mass index, pre-morbid disease, length of hospital stay.-Central venous catheter-related data: such as insertion site , number of catheter lumen, use of guide wire, duration of insertion, duration of Cather in situ, and location of insertion-Blood culture Specimen collection: This Procedure was performed by critical care nurses. It contained hand wash before the procedure, cleaning the puncture site with 10% povidone and wearing the sterile gloves. After that, blood samples were obtained from the peripheral vein utilizing strict aseptic technique measures. Next, that sample was used for qualitative culture and incubated at 37⁰C. A cultural groups within a larger culture were carried out on MacConkey’s and blood agar plates after 24, 48 and 72 hr and incubated for 24 hrs at 37⁰C. Organisms were identified by gram staining, the configuration of bacterial colony and biochemical tests achieved by routine laboratory techniques (9). Blood cultures were withdrawn at immediate admission and seven days after insertion of central venous catheterAntibiotic sensitivity testing: Antibiotic sensitivity test of bacterial strain separation on 23 frequently used antibiotics were applied on MullerHinton agar medium by disk diffusion technique according to National Committee for Clinical Laboratory Standards (NCCLS) as mentioned by (10) utilizing Disc of antibiotics such as Erythromycin (15μg), Cephalexin(30μg), Ceftriaxone(30μg), Chloramphenicol (30μg Piperacillin (100μg), Colistin(50μg), Streptomycin (25μg), Cefotaxime (30μg), Gentamycin (10μg), Amikacin (30μg), Neomycin(30μg), Vancomycin(30μg), Azithromycin (30μg), Tetracycline (30μg), Amoxicillin(30μg), Penicillin ( 10μg), Ceftazidime (30μg) , Cloxacillin (1μg), Nalidixic acid (30μg), Ciprofloxacin(5μg), Cotrimoxazole (25μg) Levofloxacin (5μg), and Imipenem (10μg) were placed on each isolated bacteria respectively and incubated at 37°C. Later, after 24 hours of incubation, the diameter of zone of inhibition that encircles the antibiotics was quantified as suggested by the Clinical Laboratory Standard Institute (11).The procedure of data collection The patients were contacted by the researchers to explain the steps of the CVP insertion and withdrawing sample for blood culture. Later the written permissions were taken from the patients to engage in the study. Next, the patients’ demographic data and clinical profile were fulfilled by the researchers from the medical records including age, sex, body mass index, pre-morbid disease, length of hospital stay. This stage consumed half an hour for each patient. Later, the nurse researchers attended the procedure of insertion of central venous catheters for each patient. Central venous CVCs were supplied as an available kit and inserted using a Seldinger technique by intensive care physician. Insertion was carried out under strict aseptic techniques (gowns, gloves, and masks). The insertion site ( jugular or subclavian ) was cleaned with 10% povidone-iodine solution for at least 1-2 min and a sterile field protected with long wraps . After sterilization of the insertion site, the physician underwent the insertion process. During this invasive intervention, the researchers observed the procedural steps and recorded the CVCs related data including the site of insertion, duration of insertion, the use of guide wire, the number of lumens, and duration of Cather in situ. . Following completion of CVC insertion, the critical care nurses withdrew the venous blood culture. The site of insertion was covered by sterile gauze and a transparent adhesive tape. This phase took 30-45 minutes for each patient. Later, the withdrawn samples were aseptically transferred to the laboratory to be cultured. Dressings were replaced if the gauze became soiled. CVCs were not routinely replaced unless they were suspected of being contaminated. The blood culture was repeated again on the seventh of insertion. After 72 hours, the researcher got the patients’ blood culture reports and recorded them. If blood culture was positive , the bacterial isolates and sensitivity test were carried out and documented . The overall data collection took 16 months starting from May 2015 to September 2016. Ethical consideration This study was authorized by the ethical committee of faculty of nursing, Cairo University. As well, written official permission was got from the head of the critical care unit at Al-Haram Hospital in Egypt. Every patient was reviewed by the researchers to explain the main issue of the study. In addition, formal consent was taken from all engaged patients. Moreover, Confidentiality of patients’ data was secured throughout the study. Content validity and reliability Content validity of study tools such as an observational checklist of central venous catheter-related data and patients’ clinical profile were reviewed by nine experts in the critical care nursing and microbiology specialties . Based on experts’ recommendations, the researchers employed the content validity index (CVI) to investigate the quantitative content validity of the established data collection tools utilizing a 4-point likert scale (12). The critical threshold value for CVI was adopted at 0.79 (Polit et al., 2007). Items that showed a CVI of 0.79 or more were incorporated in the final form of both tools . Concerning the content validity ratio, the assigned experts were requested to calculate each item quantitively on a 3-point Likert scale– distributed as follows ; important (graded 1), Useful but not important (graded 2) and not important (graded 3). In relation to the number of experts and the critical values of content validity ratio as proposed by (13). Elements that revealed a CVR of 0.5 or more were adopted . Reliability for both checklists were tested utilizing the Cronbach Alpha (r=0.83) in a pilot study of 12 patients. Data AnalysisThe present data were analyzed employing the statistical package for social sciences (SPSS) version 21. Continuous data was calculated such as mean and standard deviation (SD), while the qualitative data were illustrated as frequencies and percentages. Moreover, Chi-square was tested for correlates qualitative data. The level of significance was adopted at 0.05.Results:Patients ‘ demographic and clinical characteristics Out of 120 patients, more than half of patients (57.5%) were male, their mean age was 52.2 . Moreover, 43.3 % of patients were overweight. Regarding the clinical characteristics’ of enrolled patients , most of them were hypertensive 82(68.3%). Furthermore, the reason for the insertion of CVC in most of the patients was emergent intervention 108(90%). Concerning the duration of hospital stay, the majority of patients 81(67.5%), their duration of hospital stay was less than 10 days with the mean 9 days. (Table 1).Microbiological characteristics of the studied cases Of the 120 patients enrolled in this study, all subjects’ displayed negative blood culture i.e. no growth of microorganisms immediately after the insertion of central venous catheters. On the other hand, 13 patients (10.8%) displayed positive culture 7 days after insertion (fig.1). Concerning the finding pertinent to bacterial separates from blood cultures of infectious cases, it revealed that 10 cases were infected with Staphylococcus epidermis and the other 3 cases were infected with Staphylococcusaureus .(table 2).Catheter profile and risk factors to CRBSI among the studied patients Of the 120 critically ill patients participated in this study, all patients’ CV catheters were inserted in the critical care setting and had a three lumen (triple lumen) . In relation to the duration of CVC insertion, all thirteen cases of CRBSI spent more than 15 minutes in the procedure of CVC insertion utilizing guide wire. Furthermore , almost half of studied patients ( 52.5%) underwent insertion of central venous catheters through the jugular vein, However, the occurrence of CRBSI was higher in patients with the subclavian route ( 6.66%) when compared with Jugular route (4.16%). Regarding the duration of the central venous catheter in place, more than two-thirds of patients (67.5%) spent less than 7 days. However, all the CRBSI cases (10.83%) stayed more than seven days as seen in table 3.Cultural sensitivity of bacterial isolates to antibioticsRegarding examining he cultural sensitivity of bacterial isolates to antibiotics in the current study, it showed that all separated bacteria were sensitive to Vancomycin, Amikin, and Levofloxacin. Whereas, most of the bacterial isolates were resistant to Amoxycillin Clavulanic acid (80) . and Meropenem, (60%) as seen in figure 2).Discussion This study aimed to investigate the incidence, organisms and risk factors for central venous catheter related bloodstream infection in critical care unit at one of ministry of health hospital in Egypt. Of the 120 patients engaged in the present study, 13 (10.8%) acquired blood stream infection after seven days (fig.1). These findings are in line with (14) who investigated bloodstream infections and found that CLBSI in critically ill patients reached 6.0%. As well, the present findings are agreed with (15) who found that the ratio of blood stream infection 10.2 per one thousand catheters per day. Also, 16 found the proportion of bloodstream infection represented 1.4 per 1000 catheter per day. Similarly, our findings are in line with other previous studies done by (17-19 ) who mentioned a bloodstream infection proportion was 9.2 per 1,000 catheters / day in developing countries that have similar obstacles in Egypt such as inadequate compliance with infection control measures and the nurse-patient ratio is inappropriate On studying the separation of bacteria from blood cultures in the present study, it revealed thirteen cases of bloodstream infections, ten of these cases were infected with Staphylococcus epidermidis. The possible rationale for that finding has been related to inadequate compliance with disinfection of the skin with antiseptics surrounding insertion site of venous catheter. So, Staphylococcus epidermidis lives normally on the surface of the skin and could enter the invasive sites easily and causes infection . This finding was agreed with (20) who examined bloodstream infection in patients who underwent hemodialysis and found that most of these patients caught blood stream infection caused by Staphylococcus epidermidis. As well, the current finding is agreed with a similar study carried out by (21) who examined the incidence of bloodstream infection in a tertiary teaching hospital in India and found that negative staphylococci were the common organisms causing bloodstream infection. Furthermore, the present finding is in line with 22-24 who found a dominance of Gram-negative bacteria that may have relevant to bacterial colonization of the patients care providers’ hands. Similarly, our findings are reinforced by other study done by (25) that showed that most of Gram-negative bacteria resulting in BSI in a pediatric critical care unit . On the contrary, our finding is contradicted with a similar study done by (26) who found gram-positive cocci were the most common organisms colonizing CVCs . Regarding the study of the culture sensitivity of S aureus and S epidermidis to antibiotics , the findings revealed that these bacteria were sensitive to vancomycin, amikacin, and levofloxacin. This finding is partially agreed with another similar study done by (27) who mentioned that all isolated bacteria from CRLI were Staphylococcus and sensitive to vancomycin, teicoplanin, and linezolid. Moreover , the current finding is agreed with (28) who investigated the occurrence of bloodstream infection in the critical care unit and detected that all the bacterial isolates from blood culture were sensitive to vancomycin and teicoplanin. Respecting to the study of the antibiotic resistance of S. epidermidis isolates and S.aureus in the current study, it illustrated that the most of cases were resistant to Amoxycillin and Meropenem, on the other hand, half of the cases were resistant to ofloxacin, , ceftriaxone , and clindamycinPossible risk factors for BSI have been mentioned in previous studies, e.g., catheter type , insertion site , duration of catheterization, , duration of hospital stay, three lumen catheter . Respecting to our study, it was noticed that the average mean of hospital stay length was ten days in non infected patients. While the patients who stayed more ten days, they developed bloodstream infection. This finding is supported by (22) who studied prevalence of hospital acquired infections in Estonia and mentioned that prolonged hospital stay have been related to higher proportions of blood stream infection. Whether the number of lumens in the CVCs was associated with a higher rate of infection is controversial. In our study, the nurses utilized the three-lumen catheter (triple lumen) for all the studied patients. The possible explanation for selecting a triple lumen catheter was an administration of parenteral fluids, medications, blood products and measuring CVP. Therefore, the catheter was manipulated many times per day. Our finding is in agreement with (29-30) who detected in the multivariate analysis that the possibility of acquiring a bloodstream infection was high when a patient had used a multiple-lumen CVC compared to a one -lumen catheter. Regarding the location of patients’ CVC insertion. Our study findings revealed that all insertion cases were implemented in critical care setting and almost half of them were carried out in emergency situations. As a result, the occurrence of blood stream infection was predicted . The possible explanation is the best attention to adherence to preventive measures during the CVC insertion in emergency cases might not be achievable due to frequent handling of CV catheters per day to monitor patients’ hemodynamic status or to obtain venous samples for laboratory investigation. Our findings are matched with (31) who mentioned that the occurrence of infection is higher in critical care settings than other settings. They associated the probable reasons with the procedure of insertion of central venous catheter that might need longer duration of time in insertion and frequent handling per day for administering fluids, medications, and blood transfusion. It has been validated that insertion site of CV catheter is risk factor for the induction of blood stream infection (24). The insertion of CV catheters via jugular vein is more prone to catch infection than those inserted in the sub-clavian vein. This may have related to factors that enrich contamination of the skin next to jugular veins such as the spread of sputum droplets, difficulties in catheter fixation and frequent dressing (17).