Safety and Effectiveness of Novel Nitroglycerin Based Catheter Lock Solution

Inclusion Criteria: * Inpatients who have a long term central venous catheter (CVC)-and the CVC has been in place for at least 14 days and is expected to remain in place at least for 30 days after enrollment * The CVC consists of a 5.0 French size, dual-lumen, peripherally inserted central catheter * Patients who are willing and capable to provide Informed Consent * Patients who are willing and capable to follow the instructions required to complete the study * Females (of child bearing potential) and males (of child bearing potential) must be abstinent or agree to use birth control during the study. Exclusion Criteria: * Patients who have an antimicrobial CVC. * Patients who have a short term CVC that have been placed in ICU (mainly rigid wall CVCs placed for acute care in ICU). * Patients who are hypotensive with a systolic blood pressure reading of \<110 mmHg at any time over the 3 days prior to study entry * Patients who are not awake, not alert, or who cannot express pain or discomfort related to the catheter locks * Patients with an existing local or systemic infection as defined by evidence of fever (a body temperature \> 38.0o C with two readings taken at least 10 minutes apart or one body temperature \> 38.3o) and any of the following within 24 hours of enrollment: Pulse rate \> 100 beats/min.; Respiratory rate \> 20/min.; WBC count \>12,000/mm3, \<4,000/mm3 or differential count showing \>10% band forms. Patient will still be eligible for the study if the participant's white blood cell count (WBC) is outside normal limits due to chemotherapy treatment or underlying conditions. Systolic blood pressure \<90 mm Hg. * Signs and symptoms of localized catheter-related infection (tenderness and/or pain, erythema, swelling, purulent exudates within 2 cm of entry site) * Patients with an occluded (partially or totally) catheter defined as inability to either withdraw blood or instill 3cc of fluid without resistance through any catheter lumen * Patients with multiple co-existing central venous catheters at the time of enrollment will not be enrolled. * Patients in whom the lock solution application will interfere with routine treatment of the underlying disease * Patients with a known history of allergic reaction to ethanol, nitroglycerin, or citrate. * Female patients who are pregnant or breast feeding * Patients who are on disulfiram, metronidazole or are dependent on alcohol * Patients receiving phosphodiesterase type 5 (PDE-5) inhibitors (such as sildenafil, tadalafil, vardenafil).