Nosocomial infections associated with long-term radial artery cannulation

Noninvasive Monitoring of Arterial Pressure: Finger or Lower Leg As Alternatives to the Upper Arm: A Prospective Study in Three ICUs

OBJECTIVES

When the upper arm is inaccessible for measurements of arterial pressure (AP), the best alternative site is unknown. We performed a between-site comparison of the agreement between invasive and noninvasive readings of AP taken at the lower leg, the finger, and the upper arm. The risk associated with measurement errors and the trending ability were also assessed.

DESIGN

Prospective observational study.

SETTING

Three ICUs.

PATIENTS

Patients having an arterial catheter and an arm circumference less than 42 cm.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Three triplicates of AP measurements were collected via an arterial catheter (reference AP), a finger cuff system (ClearSight; Edward Lifesciences, Irvine, CA), and an oscillometric cuff (at the lower leg then the upper arm). Trending ability was assessed through an additional set of measurements after a cardiovascular intervention. The default bed backrest angle was respected. Failure to measure and display AP occurred in 19 patients (13%) at the finger, never at other sites. In 130 patients analyzed, the agreement between noninvasive and invasive readings was worse at the lower leg than that observed at the upper arm or the finger (for mean AP, bias ± sd of 6.0 ± 15.8 vs 3.6 ± 7.1 and 0.1 ± 7.4 mm Hg, respectively; p < 0.05), yielding a higher frequency of error-associated clinical risk (no risk for 64% vs 84% and 86% of measurements, respectively, p < 0.0001). According to the International Organization for Standardization (ISO) 81060-2:2018 standard, mean AP measurements were reliable at the upper arm and the finger, not the lower leg. In 33 patients reassessed after a cardiovascular intervention, both the concordance rate for change in mean AP and the ability to detect a therapy-induced significant change were good and similar at the three sites.

CONCLUSIONS

As compared with lower leg measurements of AP, finger measurements were, when possible, a preferable alternative to upper arm ones.

The fall and rise of cleanliness in British healthcare and the nursing contribution

This paper discusses the term ‘cleanliness’ and applies it to healthcare. Ways of achieving cleanliness in premises where healthcare is delivered are explored. It is concluded that although once a world-leader in infection control practice and research, the United Kingdom is now lagging behind other countries. Traditionally hands have been regarded as the main vectors of healthcare-associated infection. However, hands can never be rendered entirely free of micro-organisms, so it is inevitable that healthcare-associated infection will always be a challenge. Decontamination of the healthcare environment, its fixtures, fittings and clinical equipment are also of pivotal importance in maintaining cleanliness, controlling infection and regaining consumer confidence in healthcare. Nurses play a major role in ensuring that appropriate decontamination processes and procedures are in place to meet required standards. To do so they must receive the appropriate education and training.

Arterial Catheterization and Infection: Toll-like Receptors in Defense against Microorganisms and Therapeutic Implications

Radial artery catheterization has become a preferred route over femoral artery catheterization, in order to monitor the blood pressure of hemodynamically unstable patients or for repeated sampling of arterial blood gases. While the incidence of catheter-related infection is lower in the radial artery than the femoral artery, infection remains a major issue that requires attention. In this review of the literature, we discuss infectious complications of radial artery catheterization, with a focus on various risk factors and establishing the most common causative agents. We also critically review the role of the innate immune system involving Toll-like receptors (TLRs) in host-defense, with the goal of establishing a common pathway used by the innate immune system via TLRs to combat the pathogens that most commonly cause infection in radial artery catheterization. If this pathway can be therapeutically manipulated to preemptively attack pathogenic agents, immunomodulation may be an option in reducing the incidence of infection in this procedure.

Guideline for Prevention of Intravascular-Device–Related Infections

The “Guideline for Prevention of Intravascular Device-Related Infections” is designed to reduce the incidence of intravascular device-related infections by providing an over view of the evidence for recommendations considered prudent by consensus of Hospital Infection Control Practices Advisor y Committee (HICPAC) members. This two-part document updates and replaces the previously published Centers for Disease Control's (CDC) Guideline for Intravascular Infections (Am J Infect Control1983;11:183-199). Part I, “Intravascular Device-Related Infections: An Over view” discusses many of the issues and controversies in intravascular-device use and maintenance. These issues include definitions and diagnosis of catheter-related infection, appropriate barrier precautions during catheter insertion, inter vals for replacement of catheters, intravenous (IV) fluids and administration sets, catheter-site care, the role of specialized IV personnel, and the use of prophylactic antimi-crobials, flush solutions, and anticoagulants. Part II, “Recommendations for Prevention of Intravascular Device-Related Infections” provides consensus recommendations of the HICPAC for the prevention and control of intravascular device-related infections. A working draft of this document also was reviewed by experts in hospital infection control, internal medicine, pediatrics, and intravenous therapy. However, all recommendations contained in the guideline may not reflect the opinion of all reviewers.

Guidelines for the Prevention of Intravascular Catheter–Related Infections

Background:

Although many catheter-related blood-stream infections (CRBSIs) are preventable, measures to reduce these infections are not uniformly implemented.

Objective:

To update an existing evidenced-based guideline that promotes strategies to prevent CRBSIs.

Data Sources:

The MEDLINE database, conference proceedings, and bibliographies of review articles and book chapters were searched for relevant articles.

Studies Included:

Laboratory-based studies, controlled clinical trials, prospective interventional trials, and epidemiologic investigations.

Outcome Measures:

Reduction in CRBSI, catheter colonization, or catheter-related infection.

Synthesis:

The recommended preventive strategies with the strongest supportive evidence are education and training of healthcare providers who insert and maintain catheters; maximal sterile barrier precautions during central venous catheter insertion; use of a 2% chlorhexidine preparation for skin antisepsis; no routine replacement of central venous catheters for prevention of infection; and use of antiseptic/antibiotic-impregnated short-term central venous catheters if the rate of infection is high despite adherence to other strategies (ie, education and training, maximal sterile barrier precautions, and 2% chlorhexidine for skin antisepsis).

Conclusion:

Successful implementation of these evidence-based interventions can reduce the risk for serious catheter-related infection.

Catheter-related and infusion-related sepsis

This article focuses on the pathogenesis, diagnosis, prevention, and management of infectious complications of intravascular cannulation and fluid infusion. Although continuous vascular access is one of the most essential modalities in modern-day medicine, there is a substantial and underappreciated potential for producing iatrogenic complications, the most important of which is blood-borne infection. Clinicians often fail to consider the diagnosis of infusion-related sepsis because clinical signs and symptoms are indistinguishable from bloodstream infections arising from other sites. Understanding and consideration of the risk factors predisposing patients to infusion-related infections may guide the development and implementation of control measures for prevention.

Comparison of bacterial contamination of blood conservation system and stopcock system arterial sampling lines used in critically ill patients

BACKGROUND

Commonly placed to monitor blood pressure and to aspirate blood, arterial lines frequently cause complications. The blood conservation system (BCS) forms a closed infusion line and may be expected to reduce complications caused by intraluminal contamination. We compared microbial contamination resulting from use of BCS and 3-way stopcock catheterization.

METHODS

Patients who required arterial catheterization for at least 24 hours in our intensive care unit were randomly assigned to receive an arterial pressure monitoring system either with the BCS (test group) or with a 3-way stopcock (comparator group). To evaluate arterial line contamination, we qualitatively assessed the contamination of the catheter tip and intraluminal fluid.

RESULTS

We analyzed microbial contamination for a total of 216 arterial catheters: 109 in the test group and 107 in the comparator group. We found no difference in the incidence of catheter tip colonization in the 2 groups (test group, 8/109 vs comparator group, 11/107; P = .48). There was a statistically significant correlation between catheter tip colonization and duration of arterial line utilization. We found statistically significantly lower intraluminal fluid contamination in the test group (test group, 2/109 vs comparator group, 9/107; P = .03). There was no relationship between intraluminal fluid contamination and catheter tip contamination.

CONCLUSION

There was less microbial contamination of intraluminal fluid when BCS was used for arterial catheterization.

A Retrospective Study to Determine Whether accessing Frequency Affects the Incidence of Microbial Colonisation in Peripheral Arterial Catheters

Peripheral arterial catheters are used for the continuous monitoring of blood pressure and repeated blood sampling in critically ill patients, but can be a source of catheter-related bloodstream infection. A common assumption is that the more frequently an arterial catheter is accessed, the greater the likelihood of contamination and colonisation to occur. We sought to determine whether the accessing frequency has an influence on the rate of colonisation in a peripheral arterial catheter.

A retrospective, unmatched, nested case control study was conducted in our intensive care unit. The intensive care unit charts of 96 arterial catheters from 83 patients were examined to measure the number of times each respective arterial catheter was accessed. Multivariate Cox proportional hazards regression was used to compare the rate of accessing of arterial catheters and account for varying arterial catheter in situ duration. Arterial catheters which had a high access rate of 8.1 or more times/day (five colonised of 32 patients: hazards ratio 1.69, 95% confidence interval 0.52 to 5.49; P=0.77), or a medium access rate of 6.7 to 8.0 times/day (six colonised of 32 patients: hazards ratio, 1.35, 95% confidence interval, 0.37 to 4.92: P=0.65) were not significantly more colonised when compared to arterial catheters which had a low access rate of 0 to 6.6 times/day (six colonised of 32 patients), adjusted for arterial catheter insertion site and place in hospital where the arterial catheter insertion was performed.

We were unable to demonstrate that the accessing frequency of an arterial catheter was a major predisposing factor for the likelihood of colonisation. Other mechanisms other than hub colonisation should be investigated further.

Radial artery cannulation: a comprehensive review of recent anatomic and physiologic investigations

Consistent anatomic accessibility, ease of cannulation, and a low rate of complications have made the radial artery the preferred site for arterial cannulation. Radial artery catheterization is a relatively safe procedure with an incidence of permanent ischemic complications of 0.09%. Although its anatomy in the forearm and the hand is variable, adequate collateral flow in the event of radial artery thrombosis is present in most patients. Harvesting of the radial artery as a conduit for coronary artery bypass grafting, advances in plastic and reconstructive surgery of the hand, and its use as an entry site for cardiac catheterization has provided new insight into the collateral blood flow to the hand and the impact of radial arterial instrumentation. The Modified Allen's Test has been the most frequently used method to clinically assess adequacy of ulnar artery collateral flow despite the lack of evidence that it can predict ischemic complications in the setting of radial artery occlusion. Doppler ultrasound can be used to evaluate collateral hand perfusion in an effort to stratify risk of potential ischemic injury from cannulation. Limited research has demonstrated a beneficial effect of heparinized flush solutions on arterial catheter patency but only in patients with prolonged monitoring (>24 h). Conservative management may be equally as effective as surgical intervention in treating ischemic complications resulting from radial artery cannulation. Limited clinical experience with the ultrasound-guided arterial cannulation method suggests that this technique is associated with increased success of cannulation with fewer attempts. Whether use of the latter technique is associated with a decrease in complications has not yet been verified in prospective studies. Research is needed to assess the safety of using the ulnar artery as an alternative to radial artery cannulation because the proximity and attachments of the ulnar artery to the ulnar nerve may potentially expose it to a higher risk of injury.

Prospective study of peripheral arterial catheter infection and comparison with concurrently sited central venous catheters

OBJECTIVE

Peripheral arterial catheters are perceived as having low infective potential compared with other catheters and may be overlooked as a cause of catheter-related bloodstream infection. We aimed to measure colonization and rates of catheter-related bloodstream infection in arterial catheters, to investigate risk factors for arterial catheter colonization, and to compare arterial catheter infection rates with those in concurrently sited and managed central venous catheters.

DESIGN

Prospective 24-month cohort study.

SETTING

Eight-bed combined general intensive care and high-dependency unit of a 350-bed Australian teaching hospital.

PATIENTS

Three hundred twenty-one arterial catheters in 252 adult and pediatric patients were observed for 1,082 catheter days, and 618 central venous catheters in 410 patients were observed for 4,040 catheter days. All catheters were inserted in, or presented to, the intensive care unit. Both arterial catheters and central venous catheters were inserted by trained personnel under aseptic conditions, and management was standardized.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The incidence per 1,000 (95% confidence interval) catheter days of colonization (> or = 15 colonies) and catheter-related bloodstream infection was 15.7 (9.5-25.9) and 0.92 (0.13-6.44) for arterial catheters and 16.8 (13.3-21.3) and 2.23 (1.12-4.44) for central venous catheters. Arterial catheter colonization was not significantly different than that in central venous catheters (hazard ratio, 1.17; 95% confidence interval, 0.41-3.36; p = .77). Arterial catheter colonization increased with dwell time and was similar to central venous catheters over time. Femoral arterial catheters were colonized more often than radial arterial catheters (hazard ratio, 5.08; 95% confidence interval, 0.85, 30.3; p = .075), and colonization was significantly higher when the catheter was inserted in the operating theater or emergency department (hazard ratio, 4.45; 95% confidence interval, 1.42-13.9; p = .01) compared with the intensive care unit.

CONCLUSIONS

The incidence of catheter-related bloodstream infection from arterial catheters was low. However, both arterial catheter colonization and rates of catheter-related bloodstream infection were similar to those in concurrently sited and identically managed central venous catheters. By inference, the arterial catheter should be accorded the same degree of importance as the central venous catheter as a potential source of sepsis.

The risk of bloodstream infection in adults with different intravascular devices: a systematic review of 200 published prospective studies

OBJECTIVE

To better understand the absolute and relative risks of bloodstream Infection (BSI) associated with the various types of intravascular devices (IVDs), we analyzed 200 published studies of adults In which every device in the study population was prospectively evaluated for evidence of associated infection and microbiologically based criteria were used to define IVD-related BSI.

METHODS

English-language reports of prospective studies of adults published between January 1, 1966, and July 1, 2005, were identified by MEDLINE search using the following general search strategy: bacteremla [Medical Subject Heading, MeSH] OR septicemia [MeSH] OR bloodstream Infection AND the specific type of intravascular device (e.g., central venous port). Mean rates of IVD-related BSI were calculated from pooled data for each type of device and expressed as BSIs per 100 IVDs (%) and per 1000 IVD days.

RESULTS

Point incidence rates of IVD-related BSI were lowest with peripheral Intravenous catheters (0.1%, 0.5 per 1000 IVD-days) and midline catheters (0.4%, 0.2 per 1000 catheter-days). Far higher rates were seen with short-term noncuffed and nonmedicated central venous catheters (CVCs) (4.4%, 2.7 per 1000 catheter-days). Arterial catheters used for hemodynamic monitoring (0.8%, 1.7 per 1000 catheter-days) and peripherally inserted central catheters used in hospitalized patients (2.4%, 2.1 per 1000 catheter-days) posed risks approaching those seen with short-term conventional CVCs used in the Intensive care unit. Surgically implanted long-term central venous devices--cuffed and tunneled catheters (22.5%, 1.6 per 1000 IVD-days) and central venous ports (3.6%, 0.1 per 1000 IVD-days)--appear to have high rates of Infection when risk Is expressed as BSIs per 100 IVDs but actually pose much lower risk when rates are expressed per 1000 IVD-days. The use of cuffed and tunneled dual lumen CVCs rather than noncuffed, nontunneled catheters for temporary hemodlalysis and novel preventive technologies, such as CVCs with anti-infective surfaces, was associated with considerably lower rates of catheter-related BSI.

CONCLUSIONS

Expressing risk of IVD-related BSI per 1000 IVD-days rather than BSIs per 100 IVDs allows for more meaningful estimates of risk. These data, based on prospective studies In which every IVD in the study cohort was analyzed for evidence of infection by microbiologically based criteria, show that all types of IVDs pose a risk of IVD-related BSI and can be used for benchmarking rates of infection caused by the various types of IVDs In use at the present time. Since almost all the national effort and progress to date to reduce the risk of IVD-related Infection have focused on short-term noncuffed CVCs used in Intensive care units, Infection control programs must now strive to consistently apply essential control measures and preventive technologies with all types of IVDs.

Prospective study of arterial and central venous catheter colonization and of arterial- and central venous catheter-related bacteremia in intensive care units

OBJECTIVE

To compare the rates of positive quantitative culture (PQC) of arterial catheter (AC) and central venous catheter (CVC) tips and of CVC- and AC-related bacteremia in intensive care unit patients undergoing placement of both ACs and CVCs.

DESIGN

Prospective, descriptive survey. To control for a difference in the severity of patients having an AC or CVC, only patients having both an AC and a CVC were included.

SETTING

An adult, nine-bed medical/surgical intensive care unit at a university teaching hospital.

SUBJECTS

The analysis included 308 CVCs and 299 ACs inserted in 212 severely ill patients, with a mean +/- sd Simplified Acute Physiology Score II of 52 +/- 22 and an intensive care unit mortality of 33% (69 of 212).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The same insertion and maintenance procedures were used for both types of catheter. A PQC was defined by a catheter tip culture yielding >/=10(3) colony forming units/mL. Catheter-related bacteremia was defined by a PQC and a blood culture positive for the same microorganism. The cumulative incidence (PQCs/number of catheters inserted) was 9.4% (29/308) for CVCs and 7.7% (23/299) for ACs (p = .44). Incidence density (PQCs/1,000 catheter days) was 12.0 for CVCs versus 9.3 for ACs. At the femoral site, there was no significant difference between CVCs and ACs in the cumulative incidences and incidence densities of PQCs. Two instances of catheter-related bacteremia were observed, one involving a CVC and one involving an AC.

CONCLUSIONS

Among severely ill patients with both CVCs and ACs, the epidemiology of PQCs of CVCs and ACs is comparable when the same infection control measures are used for the insertion and maintenance of both types of catheters.

Guidelines for the prevention of intravascular catheter-related infections

BACKGROUND

Although many catheter-related bloodstream infections (CRBSIs) are preventable, measures to reduce these infections are not uniformly implemented.

OBJECTIVE

To update an existing evidenced-based guideline that promotes strategies to prevent CRBSIs.

DATA SOURCES

The MEDLINE database, conference proceedings, and bibliographies of review articles and book chapters were searched for relevant articles.

STUDIES INCLUDED

Laboratory-based studies, controlled clinical trials, prospective interventional trials, and epidemiologic investigations.

OUTCOME MEASURES

Reduction in CRBSI, catheter colonization, or catheter-related infection.

SYNTHESIS

The recommended preventive strategies with the strongest supportive evidence are education and training of healthcare providers who insert and maintain catheters; maximal sterile barrier precautions during central venous catheter insertion; use of a 2% chlorhexidine preparation for skin antisepsis; no routine replacement of central venous catheters for prevention of infection; and use of antiseptic/antibiotic-impregnated short-term central venous catheters if the rate of infection is high despite adherence to other strategies (ie, education and training, maximal sterile barrier precautions, and 2% chlorhexidine for skin antisepsis).

CONCLUSION

Successful implementation of these evidence-based interventions can reduce the risk for serious catheter-related infection.

Guidelines for the Prevention of Intravascular Catheter–Related Infections

These guidelines have been developed for practitioners who insert catheters and for persons responsible for surveillance and control of infections in hospital, outpatient, and home health-care settings. This report was prepared by a working group comprising members from professional organizations representing the disciplines of critical care medicine, infectious diseases, health-care infection control, surgery, anesthesiology, interventional radiology, pulmonary medicine, pediatric medicine, and nursing. The working group was led by the Society of Critical Care Medicine (SCCM), in collaboration with the Infectious Disease Society of America (IDSA), Society for Healthcare Epidemiology of America (SHEA), Surgical Infection Society (SIS), American College of Chest Physicians (ACCP), American Thoracic Society (ATS), American Society of Critical Care Anesthesiologists (ASCCA), Association for Professionals in Infection Control and Epidemiology (APIC), Infusion Nurses Society (INS), Oncology Nursing Society (ONS), Society of Cardiovascular and Interventional Radiology (SCVIR), American Academy of Pediatrics (AAP), and the Healthcare Infection Control Practices Advisory Committee (HICPAC) of the Centers for Disease Control and Prevention (CDC) and is intended to replace the Guideline for Prevention of Intravascular Device–Related Infections published in 1996. These guidelines are intended to provide evidence-based recommendations for preventing catheter-related infections. Major areas of emphasis include 1) educating and training health-care providers who insert and maintain catheters; 2) using maximal sterile barrier precautions during central venous catheter insertion; 3) using a 2% chlorhexidine preparation for skin antisepsis; 4) avoiding routine replacement of central venous catheters as a strategy to prevent infection; and 5) using antiseptic/antibiotic impregnated short-term central venous catheters if the rate of infection is high despite adherence to other strategies (i.e., education and training, maximal sterile barrier precautions, and 2% chlorhexidine for skin antisepsis). These guidelines also identify performance indicators that can be used locally by health-care institutions or organizations to monitor their success in implementing these evidence-based recommendations.

Guidelines for the prevention of intravascular catheter-related infections

BACKGROUND

Although many catheter-related bloodstream infections (CR-BSIs) are preventable, measures to reduce these infections are not uniformly implemented.

OBJECTIVE

To update an existing evidenced-based guideline that promotes strategies to prevent CR-BSIs.

DATA SOURCES

The MEDLINE database, conference proceedings, and bibliographies of review articles and book chapters were searched for relevant articles.Studies Included: Laboratory-based studies, controlled clinical trials, prospective interventional trials, and epidemiological investigations.

OUTCOME MEASURES

Reduction in CR-BSI, catheter colonization, or catheter-related infection.

SYNTHESIS

The recommended preventive strategies with the strongest supportive evidence are education and training of healthcare providers who insert and maintain catheters; maximal sterile barrier precautions during central venous catheter insertion; use of a 2% chlorhexidine preparation for skin antisepsis; no routine replacement of central venous catheters for prevention of infection; and use of antiseptic/antibiotic impregnated short-term central venous catheters if the rate of infection is high despite adherence to other strategies (i.e. education and training, maximal sterile barrier precautions and 2% chlorhexidine for skin antisepsis).

CONCLUSION

Successful implementation of these evidence-based interventions can reduce the risk for serious catheter-related infection.

Guidelines for the prevention of intravascular catheter-related infections. The Hospital Infection Control Practices Advisory Committee, Center for Disease Control and Prevention, U.S

These guidelines have been developed for practitioners who insert catheters and for persons responsible for surveillance and control of infections in hospital, outpatient, and home health-care settings. This report was prepared by a working group comprising members from professional organizations representing the disciplines of critical care medicine, infectious diseases, health-care infection control, surgery, anesthesiology, interventional radiology, pulmonary medicine, pediatric medicine, and nursing. The working group was led by the Society of Critical Care Medicine (SCCM), in collaboration with the Infectious Disease Society of America (IDSA), Society for Healthcare Epidemiology of America (SHEA), Surgical Infection Society (SIS), American College of Chest Physicians (ACCP), American Thoracic Society (ATS), American Society of Critical Care Anesthesiologists (ASCCA), Association for Professionals in Infection Control and Epidemiology (APIC), Infusion Nurses Society (INS), Oncology Nursing Society (ONS), Society of Cardiovascular and Interventional Radiology (SCVIR), American Academy of Pediatrics (AAP), and the Healthcare Infection Control Practices Advisory Committee (HICPAC) of the Centers for Disease Control and Prevention (CDC) and is intended to replace the Guideline for Prevention of Intravascular Device-Related Infections published in 1996. These guidelines are intended to provide evidence-based recommendations for preventing catheter-related infections. Major areas of emphasis include 1) educating and training health-care providers who insert and maintain catheters; 2) using maximal sterile barrier precautions during central venous catheter insertion; 3) using a 2% chlorhexidine preparation for skin antisepsis; 4) avoiding routine replacement of central venous catheters as a strategy to prevent infection; and 5) using antiseptic/antibiotic impregnated short-term central venous catheters if the rate of infection is high despite adherence to other strategies (ie, education and training, maximal sterile barrier precautions, and 2% chlorhexidine for skin antisepsis). These guidelines also identify performance indicators that can be used locally by health-care institutions or organizations to monitor their success in implementing these evidence-based recommendations.

Clinical review: complications and risk factors of peripheral arterial catheters used for haemodynamic monitoring in anaesthesia and intensive care medicine

In order to evaluate the complications and risk factors associated with peripheral arterial catheters used for haemodynamic monitoring, we reviewed the literature published from 1978 to 2001. We closely examined the three most commonly used arterial cannulation sites. The reviewed papers included a total of 19,617 radial, 3899 femoral and 1989 axillary artery catheterizations. Factors that contribute to higher complication rates were investigated. Major complications occurred in fewer than 1% of the cases, and rates were similar for the radial, femoral and axillary arteries. We conclude that arterial cannulation is a safe procedure.

A 25-year study of nosocomial bacteremia in an adult intensive care unit

OBJECTIVE

To identify the organisms, their antibiotic susceptibility, and the associated focus on infection causing nosocomial bacteremia in patients in an adult intensive care unit (ICU) between 1971 and 1995.

DESIGN

Prospective observational study.

SETTING

A 12-bed general adult ICU in a 1,000-bed tertiary referral teaching hospital.

PATIENTS

Four hundred eighty-six episodes of bacteremia involving 570 organisms in 425 patients.

MEASUREMENTS AND MAIN RESULTS

Blood cultures taken from patients with suspected nosocomial infection were analyzed. Isolated organisms were identified, and their susceptibility to commonly used antibiotics was determined. Clinical details, including antibiotic treatment, were recorded for all patients. From 1986 to 1995, culture results of samples obtained from other sites were used to help identify the focus of infection causing bacteremia. All results were collected prospectively by clinical microbiologists. Between 1971 and 1990, the number of bacteremias and the relative frequency of isolation of individual organisms changed little, with Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Klebsiella species predominating. During 1991 to 1995, the number of bacteremias increased two-fold, largely attributable to increased isolation of Enterococcus species, coagulase-negative staphylococci, intrinsically antibiotic-resistant gram-negative organisms (particularly P. aeruginosa), and Candida species. The most commonly used antibiotics for the treatment of bacteremic patients throughout the 1970s were amoxicillin and gentamicin. After the introduction of cephalosporins in the early 1980s, their use increased progressively to equal that of gentamicin in the 1990s, whereas amoxicillin use decreased. Since the introduction of cephalosporins, increases in the antibiotic resistance of gram-negative organisms have been largely confined to an outbreak of gentamicin- and ceftazidime-resistant organisms caused by contaminated arterial pressure monitors during 1992 and 1993 and a two-fold increase in ceftazidime resistance of the Pseudomonas species. Gentamicin resistance of gram-negative aerobes remained unchanged (excluding the arterial pressure monitor outbreak), despite gentamicin being one of the most frequently prescribed antibiotics throughout the 25-yr period. Between 1986 and 1995, two thirds of all bacteremic organisms were cultured from intravascular catheters, which were designated as the focus of infection, 7% were secondary to gastrointestinal pathology, but only approximately 3% were secondary to wound, respiratory tract, or urinary tract infections.

CONCLUSIONS

Bacteremias have become more frequent in the ICU, probably because of the increased use of intravascular catheters, which are the most frequent foci for bacteremic infection. The spectrum of organisms has changed, and this can be temporally related to the changes in the antibiotics prescribed. Gentamicin resistance of gram-negative organisms has not increased during a 25-yr period, despite being one of the most frequently prescribed antibiotics in the ICU.

Specific problems of arterial, Swan-Ganz, and hemodialysis catheters

In our experience, the incidence and pathogenesis of colonization may vary in different types of catheters. Arterial, Swan-Ganz, and hemodialysis catheters are good examples of this problem. This observation has implications for diagnosis, and the best method for each type of catheter may not be the same. In our opinion, laboratory diagnosis in daily practice should be limited to external surface cultures of the tip of intravascular catheters. Intraluminal cultures should be limited to research purposes, except in catheters used for parenteral nutrition or hemodialysis. In this case, the intradermal segment gives more sensitive information. Sensitivity in diagnosing pulmonary artery colonization can be improved by evaluating both the tip and intradermal segments. In presence of an indwelling introducer the intradermal segment should be replaced by the introducer tip.

Coagulase-negative staphylococcal bacteraemia with special reference to septic shock: experience in an intensive care unit

During a period of 4.5 years, 48 patients with bacteraemia due to coagulase-negative staphylococci were studied prospectively in order to evaluate their clinical profile, management and outcome. There were 25 males and 23 females with ages ranging between 13 and 100 years. Over 60% of patients belonged to the age group 30 to 69 years. Shock was recorded in 23 (48%) of the 48 patients. Of the shocked patients, 16 were immunocompromised and also had abnormal coagulation. Their mortality was 44%. By contrast, none of the immunocompromised patients without shock died. Abnormal coagulation was found in 17 patients without septic shock. Their mortality was 5.9%. The commonest underlying disease was respiratory failure especially in shocked patients. The source of infection was identified in the majority of cases. In addition, most patients had an indwelling intravascular catheter especially an arterial one. The overall mortality was 16.7% (8/48). It was significantly higher in patients with shock than in those without shock (30.4% vs. 4.0%, P < 0.05).

Nurses' hands as vectors of hospital-acquired infection: a review

Hospital-acquired infections (HAI) are notorious for the manner in which they complicate the course of the original illness, increase costs of hospital stay and delay recovery. This review will briefly outline the problems presented by HAI in developed countries and present evidence that Staphylococcus aureus and gram negative bacilli, the main causative agents, reach susceptible patients via the contact rather than airborne route, predominantly on the hands of hospital staff. Good hand hygiene could help reduce the economic burden and patient distress caused by HAI, but there is evidence that it is infrequently and poorly performed by nurses, the health care staff most frequently in continuous contact with patients. Possible reasons are explored in an attempt to identify strategies to improve hand hygiene.