A 72-year-old man with a history of stroke, hypertension, hyperlipidemia, and metastatic lung cancer with known metastases to the brain and bone presents with status epilepticus. The patient had four generalized tonic clonic seizures lasting less than 1 minute each. He was initially treated with 6 mg of lorazepam en route, but his seizures persisted. Upon arrival in the emergency department he was intubated, loaded with phosphenytoin, and transferred to the neurologic intensive care unit (NeuroICU), and EEG monitoring was initiated. In the NeuroICU he continued to have convulsive and nonconvulsive seizures, eventually requiring high doses of midazolam and propofol to create burst suppression. His tunneled chemotherapy port was accessed for immediate infusion of midazolam. In addition, a radial arterial line was placed for blood pressure monitoring. His seizures stop on hospital day 4, but then he develops a fever of 101.9°F (38.8°C) on hospital day 6.
Would you have concern for central line–associated bloodstream infection in this patient?
Diagnostic evaluation of fever in a patient in the NeuroICU can be challenging. Despite testing for infectious etiology of fever, many NeuroICU patients do not have an infectious source identified. Catheter-related bloodstream infections (CRBSIs) are relatively common hospital-acquired infections causing fever in the critical care setting. CRBSIs are the most common cause of nosocomial bacteremia, accounting for significant morbidity and mortality.1 Many types of catheters are utilized in the management of critically ill patients, including peripheral intravenous lines, arterial catheters, and central venous catheters (CVCs). All catheter types have potential to cause bloodstream infections, albeit with varying frequency depending on the catheter type and anatomic location. Peripheral venous catheters, arterial lines, and midline catheters have been reported as having lower rates of CRBSIs than CVCs.2 CVCs are commonly used in the ICU for administration of medication, fluid resuscitation, transfusing blood products, hemodialysis, parenteral nutrition, intravascular cooling, and hemodynamic monitoring.3
Studies suggest that placement of nontunneled subclavian catheters may pose a reduced risk of a CRBSI when compared with femoral or internal jugular vein insertion.4 Numerous risk factors for CRBSIs have been described (Table 55-1).
| Duration of catheterization |
| Conditions of insertion, submaximal barrier precautions during insertion, and emergent procedure |
| Nontunneled compared with tunneled catheters |
| Femoral or internal jugular compared with subclavian insertion |
| Bare compared with antibiotic-impregnated catheters |
| Catheter site care |
| Skill of the catheter inserter |
| Parenteral nutrition |
| Immunocompromised patient |
Laboratory results reveal a leukocytosis of 18,000 B/L with 12% immature band forms. The patient has become hypotensive and is started on norepinephrine to maintain his mean arterial pressure of > 65 mm Hg. Blood, urine, and sputum cultures are collected, and the patient is started on broad spectrum antibiotics with vancomycin and cefepime while culture data are pending.
Critically ill patients with fever and indwelling CVCs should raise the suspicion for a possible CRBSI. Fever is the most sensitive clinical finding for central line associated blood stream infection (CLABSI) but has poor specificity.9
Blood cultures should be collected prior to initiation of antimicrobial therapy in order to increase the yield of isolating the pathogen.9 Paired blood samples from the catheter and from a peripheral vein should be drawn, with labeling of the bottles accordingly. If a blood culture cannot be drawn from a peripheral vein, it is recommended that two or more blood samples should be obtained through different catheter lumens.5,9 Drawing blood cultures from a central line hub is associated with false-positive culture results, compared with cultures from a peripheral venipuncture.9 Adequate catheter hub and skin preparation with alcohol, iodine tincture, or chlorhexidine decrease blood culture contamination,5,9
Inflammation at the insertion site carries high specificity but poor sensitivity for CRBSI.9 Erythema, tenderness, or purulent drainage at the catheter site should raise concern for catheter infection, and the catheter should be removed.9 In the absence of obvious purulence at the catheter insertion site or along the tunnel tract, the catheter can be retained until blood culture results become available. Retention of a CVC is appropriate for an ICU patient with new fever while blood cultures are pending, provided that the patient is hemodynamically stable and without a pacemaker, prosthetic valve, or recent vascular graft. Catheter removal can be an option reserved for patients in whom blood cultures are positive or who are hemodynamically unstable (Figure 55-1).5,9
There are various means by which catheters become infected and cause bacteremia. The outer surface of the catheter along the catheter tract can become colonized with bacteria, most notably by skin flora. Bacteria then proliferate on the catheter surface and on the inner lumen. Bacteria are shed from the catheter and enter the bloodstream. Organisms can also be introduced into the lumen of the catheter through poor technique while accessing lines. Less common means of infection include hematogenous seeding of central lines during bacteremia from a distant source or by administration of contaminated infusate.3
The microbiology laboratory calls to inform the resident that both sets of blood cultures are positive for gram-positive cocci in clusters. Vancomycin is continued.
Common causes of nosocomial bloodstream infections include gram-positive pathogens such as staphylococcal species and enterococci. Gram-negative organisms account for approximately 25% of all hospital-acquired bacteremias, whereas fungal pathogens, such as Candida species, cause nearly 10% of such infections.10
