Central Venous Catheter Occlusion Management Learning Module September 2013 adapted from Calgary Zone Alberta Health Services Education Table of Contents Introduction 3 Qualification 6 Objectives 7 Target Audience 8 Required Reading 9 Types of Occlusion 10 Non-Thrombotic Occlusions 13 Thrombotic Occlusions 26 Assessment of Occlusion 37 Catheter Clearance Agents 44 Calculating Catheter Lumen Volume 72 Instillation of Catheter Clearance Agents 77 Education and Documentation 85 Learning Resources and Activities 91 Frequently Asked Questions 97 Post-Test 104 Skills Checklist 112 Introduction • Occlusion is one of the most common complications associated with central venous catheters • It is a significant complication because it can result in: – – – – – Infusion therapy being disrupted Thrombosis of the blood vessel Infection Infiltration and extravasation Need for catheter removal or replacement Whenever possible… • “Salvaging the dysfunctional catheter, as opposed to removal and insertion of a replacement, is the preferred approach” (Haire, WD., & Herbst, SF., 2000) If catheter patency is not restored… • “…catheter removal should be considered ...” (INS, 2011, p.S77). • “…microbiological studies have shown that the proteins within a clot, such as fibrinogen and fibronectin, attract staphylococcal species and enhance their adherence to the catheter surface, thereby increasing the risk of catheter infection” (Baskin, JI, Pui, Ch and Reiss, U et al, 2009, 164) Qualification • Management of occluded central venous catheters (CVCs) is a specialized clinical competency which is defined as any procedure that requires the nurse to have additional cognitive and psychomotor skill and qualification prior to performing the procedure. • Qualification is achieved by successfully completing the educational program which includes the following components: – Covenant Health policies, procedures and protocols – Learning module – Qualification examination - Obtain 85% prior to demonstration of skills – Skill demonstration as per checklist Objectives On completion of the learning module, the learner will be able to: • Identify the different types of central venous catheter occlusions • Describe assessment of an occluded catheter • Describe methods to restore catheter patency • Differentiate the various types of catheter clearance agents • Describe how to calculate catheter clearance volume • Distinguish between the various methods of catheter clearance instillation • Describe required patient and staff education • Describe required documentation • Successfully demonstrate occlusion management procedures as per checklist Target Audience • Nurses who will be a Unit resource • Nurses in specialized areas where this skill is deemed necessary • Prior to undertaking this module, the nurse must be qualified in: – CVC - General Care and Maintenance – CVC - Removal. Required Reading • Covenant Health- Central Venous Catheter Occlusion Management Procedure – – Appendix A Medical Protocol for Occlusion Management – Appendix B Priming Volumes and Catheter Composition • Covenant Health Latex Allergy Precautions – Care of the Patient/ Client/Resident, Corporate Policy #VII-B-105 Types of Occlusions Types of Occlusions • It is estimated that 25% of catheters will become occluded • Signs that may indicate a catheter occlusion include: – Unable to flush or aspirate - complete occlusion – Able to flush but unable to aspirate - withdrawal occlusion – Increased resistance to flushing - sluggish catheter Types of Occlusions • Types of occlusions include: – Thrombotic – Non-thrombotic • While the majority of occlusions are thrombotic, the literature states 42% are nonthrombotic • Occlusions may have more than one cause Genentech Inc. Non-Thrombotic Occlusions Non-thrombotic Occlusions There are 4 types of non-thrombotic occlusions including: 1. 2. 3. 4. Mechanical Malpositioned tip Drug or mineral precipitate Lipid residue Mechanical Occlusions • Mechanical occlusions are caused by an external factor that prevents flushing or aspiration • Examples of mechanical occlusions include: – Closed clamps – Tight sutures around catheter – Kinked catheter or tubing – Clogged injection cap – Catheter collapsing with forceful aspiration – Incorrect placement of non-core needle in implanted port – Incorrect length of non-coring needle in implanted port – Pinch-off syndrome Mechanical Occlusions • When a catheter appears to be occluded, the first step is to rule out a mechanical obstruction Mechanical Occlusions Incorrect Placement of Non-Core Needle • Remember, if unable to flush or aspirate blood with an implanted port the first step is to re-access to rule out needle malposition Mechanical Occlusions Pinch-Off Syndrome • Catheters inserted into the subclavian vein may be “pinched off” between the clavicle and first rib • Signs and Symptoms: – inability to infuse and/or withdraw that is resolved when changing the patient’s position (raising arms or rolling shoulders forward) • Chest X-ray must be taken to confirm pinch-off syndrome • If pinch-off syndrome confirmed on CXR – catheter must be removed due to risk of catheter rupture or fracture Catheter Tip Malposition • Ideal CVC tip placement is in the lower 1/3 of the SVC • Incidence of malposition has been reported to be as high as 29% for CVCs inserted in the subclavian vein and up to 55% for PICCs • Factors that may increase the incidence of malposition include: – Initial tip placement not in the lower 1/3 of SVC – Increased intrathoracic pressure coughing and vomiting – Vigorous movements of upper extremities – Inadequate catheter securement Catheter Tip Malposition • In addition to the inability to infuse and/or withdraw, there may be additional signs and symptoms of catheter tip malposition including: – Change in length of external portion of catheter – Arm or shoulder discomfort – Arrhythmias – Feeling a sensation in neck or hearing a gurgling sound during infusion Catheter Tip Malposition • If any of the additional signs and symptoms of catheter tip malposition exist, radiographic studies must be undertaken prior to instilling a catheter clearance agent • Possible interventions to assist with tip reposition include: – repositioning patient – coughing – vigorous flushing of catheter, if appropriate Drug or Mineral Precipitates • Causes of drug or mineral precipitates include: – Drug crystallization – Drug-drug incompatibility – Drug-solution incompatibility • Drugs that are notorious causes of precipitate include: – Phenytoin – Heparin (given after a drug without first flushing with normal saline) – Calcium and phosphate safeinfusiontherapy.com Drug or Mineral Precipitates Understanding drug precipitate is simple chemistry. • Acidic drugs (low pH) are more soluble in an acidic environment. They will have a tendency to precipitate when mixed with a basic drug (high pH). • Basic drugs (high pH) are more soluble in a basic environment. They will have a tendency to precipitate when mixed with an acidic drug (low pH). Lipid Residue • Lipid residue – Drugs with lipid-containing vehicles (eg. Propofol) – Total nutrient admixtures (3-in-1) • The exact cause of the waxy lipid build-up is unknown; however, formation of a lipid protein complex has been suggested Lipid Residue • It is often difficult to distinguish between lipid and thrombotic occlusions. • Typically with a lipid occlusion, increasing resistance to flushing will be noted for several days prior to the catheter completely occluding with lipid sludge. • In some cases, a waxy like substance may be visualized in the hub of the catheter when the cap is removed. Thrombotic Occlusions Thrombotic Occlusions • Thrombotic occlusions involve the formation of fibrin or thrombus within/around the CVC or in the surrounding vessel. • 4 types of thrombotic occlusions include: – – – – Intraluminal thrombus Fibrin tail Fibrin sheath or sleeve Mural thrombus Thrombotic Occlusions • Thrombotic occlusions involve the formation of fibrin or thrombus within/around the CVC or in the surrounding vessel. • 4 types of thrombotic occlusions include: – – – – Intraluminal thrombus Fibrin tail Fibrin sheath or sleeve Mural thrombus Four Types of Thrombotic Occlusions • Forms inside catheter lumen • May cause partial or complete occlusion • Fibrin extends from the end of the catheter • Can act as a oneway valve causing a partial occlusion Images courtesy of Genentech, Inc. used with permission. • Fibrin from vessel wall injury binds to fibrin on catheter surface • May cause venous thrombus as well as catheter obstruction • Forms when fibrin adheres to the external catheter surface, encasing it like a sock, covering the opening of the catheter tip Haire WD. J Vasc Access Devices. 2000; Wingerter. L. Clin J Oncol Nurs. 2003; 7:435 Intraluminal Thrombus • Internal lumen of catheter is obstructed either by clotted blood or the accumulation of fibrin. • Coagulation and clot formation results from inadequate flushing or reflux of blood due to negative pressure within the catheter (i.e. coughing, valsalva maneuver, failure to use positive pressure). Genentech Inc. Fibrin Tail • Platelet aggregation and fibrin accumulation can cause a “tail” of fibrin that extends off the end of the catheter tip. • The tail may not interfere with infusion but may occlude the catheter during aspiration, if it is drawn up against the tip. This type of occlusion is called a withdrawal occlusion. Genentech Inc. Fibrin Sleeve or Sheath • Platelet aggregation and fibrin deposit encase the external surface of the catheter and form a sac around the distal end. • The sleeve or sheath may cause retrograde flow of infusate back up the length of the catheter. • If the sleeve or sheath extend to the vein insertion site, the infusate may even be observed on the skin, or in subcutaneous pocket. Genentech Inc. Genentech Inc. Mural Thrombus • Endothelial damage to the blood vessel results in fibrin deposition at the point of cellular damage. • If the thrombus occurs only along the wall of the vein, it is called a mural thrombus. • If thrombus completely occludes the vein, it is called a venous thrombus. Genentech Inc. • If mural or venous thrombosis involves the tip of the catheter, obstruction may occur. Assessment for Occlusion Management Risk vs. Benefit • Although occlusion management has many benefits, it may also be associated with some risks including: – Releasing bacteria into the venous system that may have been embedded in the clot, biofilm, fibrin, or precipitate – Adverse reactions to catheter clearance agent – Catheter damage – Embolization of clot, precipitate or catheter Risk vs. Benefit When assessing risk vs. benefit, the following questions may assist in determining if the occlusion should be managed or the catheter removed: • Is the CVC still required? If so, for how long? • Are there any other venous access options? Would alternate appropriate venous access be easily obtained? • Is there a suspected or confirmed catheter related infection? • Are there any contraindications to using a specific unblocking agent? The main question that must be answered is: Does the need to salvage this catheter outweigh the risks associated with treating the occlusion? Assessment • Prior to initiating occlusion management the qualified nurse must confirm: – The type of catheter – That an occlusion exits and the most likely cause • The qualified nurse must also review the patient’s physical status, allergies and any other contraindications to using the catheter clearance agent Assessing Type of Catheter Tunneled CVCs, PICCs and Implanted Ports Unblocking procedures may be used if deemed appropriate Direct Percutaneous CVCs and Midlines Blocked lumens should be labeled as blocked and consideration given to removing catheter as soon as possible. If catheter is not removed, manage the occlusion. Apheresis or Dialysis Catheters Blocked lumens must be managed by qualified staff in those specialty areas Assessing the Cause • • • • • • • Does patient have a history of hypercoagulation? Have mechanical causes of occlusion been ruled out? Are there any indications that the tip may be malpositioned? What was the last medication infused? Is the patient receiving incompatible medications? Has the catheter been flushed with saline between infusions/medications? Is the catheter locked with heparin? Assessing the Cause • Are drugs with lipid containing vehicles or TNA being infused? • Did the occlusion develop suddenly or over several days? • Has the catheter been used for blood sampling? • Are push/pause flushing and positive pressure being used? • Are blood or lipids visible in the catheter? Catheter Clearance Agents Catheter Clearance Agents Indication Clearance Agent Thrombotic Occlusions Alteplase (Cathflo) Lipid Occlusions Ethyl Alcohol Precipitates of low pH (acidic) drugs or calcium phosphorus precipitates Hydrochloric Acid Precipitates of high pH (alkaline) drugs Sodium Bicarbonate i.e. gancyclovir, acyclovir, ampicillin, phenytoin, septra The most common type of occlusion is thrombotic. If an occlusion is caused by precipitate or lipid, contact site resource for assistance with occlusion management. Note... • The majority of catheter occlusions are thrombotic, therefore, if unable to determine the cause of the occlusion, and there are no contraindications, a thrombolytic should be tried first. Genentech Inc. pH of common drugs Medication Alkaline Acidic pH Unblocking Agent Ampicillin 8 - 10 Sodium Bicarbonate Dilantin 10 - 12 Acyclovir 10 - 12 Gancyclovir 11 Vancomycin 2.5 – 4.5 Ciprofloxacin 3.5 – 4.6 Dopamine 3.3 – 3.6 Gentamicin 3.0 – 5.5 Morphine 2.5 – 6.5 Amikacin 3.5 – 5.5 Piperacillin/Tazobatam 4.5 – 6.9 Hydrochloric Acid Note: Information regarding pH of medications is located in Micromedix – Trissel’s IV Compatibility Note: Some medications have a tendency to precipitate which is not related to pH. The use of sodium bicarbonate or hydrochloric acid is unlikely to be effective. Some examples include: cloxacillin, heparin, diazepam Cathflo Description • Converts plasminogen to plasmin which initiates local fibrinolysis. Indications and Usage • Cathflo is indicated for restoration of function to CVCs - as assessed by the ability to withdraw blood. Genentech Inc. Cathflo Breaks Down the Clot Genentech Inc. See How Cathflo Works • http://www.cathflo.com/moa/index.jsp Cathflo Efficacy • Efficacy has been shown in 2 major studies – COOL-1 and COOL-2 Concentration • Cathflo 2mg vial – 1 mg/mL Preparation • • • • • • Add 2.2 mL of sterile water for injection (nonbacteriostatic) Do not shake vial – swirl and/or invert gently to mix Attach a 5 micron filter needle to 10mL syringe Withdraw 2mL (2mg) of solution from the reconstituted vial Remove the filter needle from syringe Note: For patients with a latex allergy, prepare medication according Covenant Health Policy & Procedure. Stability • • Reconstituted vial may be stored for 8 hours when stored between 2 - 30° C Unreconstituted vials must be refrigerated Genentech Inc. Cathflo Instillation Volume • 2 mL or equal to volume of catheter lumen, if indicated Dwell Time • 30 -120 minutes • May be left in catheter overnight if required • Aspirate 4-5mLs and discard • May repeat dose x 1 Genentech Inc. Monitoring • Baseline BP, pulse, respirations and temperature Cathflo Genentech Inc. Cathflo Contraindications • Cathflo should not be administered to patients with known hypersensitivity to Alteplase or any component of the formulation. Precautions • Caution with patients who have active internal bleeding or who have had any of the following within 48 hours: – Surgery – Obstetrical delivery – Percutaneous biopsy of viscera or deep tissues or puncture of non-compressible vessels • Caution with patients who have thrombocytopenia, other hemostatic defects or any condition for which bleeding is a significant risk or would be difficult to manage because of its location or who are at high risk for embolic complications (venous thrombosis in the region of the catheter) • Use in pregnancy only if potential benefit justifies the potential risk to the fetus • Caution in the presence of known or suspected infection in the catheter Genentech Inc. Reconstituting Cathflo See Resource List for video Ethyl Alcohol Description • Acts as a solvent to dissolve the lipid residue Indications and Usage • Lipid occlusions in central venous catheters Efficacy • In a study by Werlin (1995), 58% of catheters thought to be occluded with lipid were cleared with ethyl alcohol. Ethyl Alcohol Concentration • 70% ethyl alcohol for injection Preparation • • Prepared by pharmacy Supplied in vial Stability • May be stored for 24 hours at room temperature Instillation Volume • Equal to volume of catheter lumen Ethyl Alcohol Dwell Time • • • 60 minutes Aspirate 3mLs and discard May repeat dose x 1 Monitoring • Baseline BP, pulse, respirations and temperature Ethyl Alcohol Adverse Reactions • • • • • Sepsis Tiredness Headaches Dizziness Nausea Contraindications • • Hypersensitivity to ethanol DO NOT use with polyurethane catheters Precautions • • Patients should be advised not to drive following instillation of ethanol Caution in the presence of known or suspected infection in the catheter Hydrochloric Acid Description • Dissolves drug precipitate by altering the pH in the catheter. Acidic drugs become more soluble in an acidic environment Indications and Usage • Calcium phosphorus precipitates or precipitates of low pH drugs in CVCs i.e. amikacin, piperacillin, vancomycin, heparin, morphine, adriamycin, ciprofloxacin Efficacy • In a study by Duffy, et al (1989), 58% of occlusions attributed to mineral precipitate cleared with HCl Hydrochloric Acid Concentration • 0.1 N (molar) Preparation • • Prepared by pharmacy Supplied in vial Stability • May be stored for 24 hours at room temperature Instillation Volume • Equal to volume of catheter lumen Hydrochloric Acid Dwell Time • • • 20-60 minutes Aspirate 3mL and discard May repeat dose x 3 Monitoring • Baseline BP, pulse, respirations and temperature Hydrochloric Acid Adverse Reactions • • • Febrile reaction Sepsis Otherwise, minimal risk of adverse reactions when used for occlusion management Contraindications • None Precautions • • DO NOT use hydrochloric acid (HCL) after sodium bicarbonate (or vice versa) – even in final effort to clear a catheter. The combination could generate heat and damage the catheter material. Measures must be taken to protect the patient and the nurse from a potential splash to eyes or exposed skin Sodium Bicarbonate Description • Dissolves drug precipitate by altering the pH in the catheter. Alkaline drugs become more soluble in an alkaline environment Indications and Usage • Precipitates of high pH drugs in CVCs i.e. gancyclovir, acylovir, ampicillin, phenytoin, septra Efficacy • Although literature describes the use of sodium bicarbonate, there are no reported statistics on the efficacy Sodium Bicarbonate Concentration • 8.4% NaHCO3 Preparation • • Prepared by pharmacy Supplied in vial Stability • May be stored for 24 hours at room temperature Instillation Volume • Equal to volume of the catheter lumen Sodium Bicarbonate Dwell Time • • • 20-60 minutes Aspirate 3mLs and discard May repeat dose x 1 Monitoring • Baseline BP, pulse, respirations and temperature Sodium Bicarbonate Adverse Reactions • • • Febrile reactions Sepsis Otherwise, minimal risk of adverse reactions when used for occlusion management Contraindications • None Precautions • DO NOT use sodium bicarbonate after hydrochloric acid (or vice versa) – even in final effort to clear a catheter. The combination could generate heat and damage the catheter material. Calculating Lumen Volume Calculating Lumen Volume • • • Calculating lumen volume may rarely be required when instilling catheter clearance agents If catheter has been trimmed on insertion you will need to calculate volume after trimming To calculate lumen volume refer to: – catheter insertion record – Appendix 2 – Priming Volumes and Catheter Composition Calculating Lumen Volume Example • 4 FR Groshong PICC originally 60 cm long with a volume 0.45 mL • Inserted length 37 cm, external length 3 cm (remember to add 2 cm for hub) Calculation 60 cm = 42 cm 0.45 mL X Lumen Volume = 0.32mL Calculating Lumen Volume Example • Implanted port: Bard PowerPort isp MRI implanted port – (no documentation of trimmed length) • Non-Core Needle: Bard Safestep 22 gauge without needleless y-site Calculation • Power Port: 1.5 mL volume • Safestep Non-Coring Needle: 0.3mL volume Lumen Volume = 1.8mL (before trimming) Instillation of Catheter Clearance Agents Instillation of Catheter Clearance Agents Technique Indication Direct Instillation Technique Withdrawal occlusion or sluggish catheter Negative Pressure Technique Without Stopcock Complete occlusion Negative Pressure Technique Using Stopcock Complete occlusion when catheter clearance agent is supplied in syringe smaller than 10 mL . Direct Instillation Technique Indication • Withdrawal occlusion or sluggish catheter Technique • Flush catheter with saline • Direct instillation of agent • Allow agent to dwell for appropriate amount of time • Withdraw and discard agent • Flush catheter well with NS Negative Pressure Technique No Stopcock Indication • Complete Occlusion Technique • Create negative pressure with empty syringe • Instill agent using gentle push/pull action – DO NOT use force when pushing • Allow agent to dwell for appropriate amount of time • Withdraw and discard agent • Flush catheter well with NS Negative Pressure Technique No Stopcock See Resource List for video Negative Pressure Technique Stopcock Indication • Complete occlusion when catheter clearance agent is supplied in syringe smaller than 10mL Technique • Using stopcock create negative pressure • Open stopcock to catheter clearance agent • Allow agent to dwell for appropriate amount of time • Withdraw and discard agent • Flush catheter well with NS Negative Pressure Technique Stopcock Preparing Supplies See Resource List for video Negative Pressure Technique Stopcock Procedure See Resource List for video Education and Documentation Education • Prior to instillation of an agent, explain the procedure and instruct the patient regarding possible adverse effects of the catheter clearance agent • Post instillation of an agent, instruct the patient about safe behaviours and mandatory restrictions regarding the use of the catheter, including: – Lumen to remain labelled – Adverse reactions – Lumen not to be used until agent removed – Any agent specific precautions Documentation • Label the lumen with a “Medication Added” label with the following: – DO NOT USE – Medication – amount – date – time – signature Documentation Post instillation of agent, document in patient’s health record: • Education • Baseline vital signs (if required) • Catheter clearance agent instilled • Lumens instilled • Do not use labeled lumen • Dwell time required Documentation Post aspiration of agent, document in patient’s health record: • Number of attempts • Outcome of procedure • Patient’s response to procedure • Recommendations for any required changes in procedures for maintenance of catheter patency. Learning Resources and Activities Additional Learning Resources • Site / Provincial Drug Monographs • Package insert for the appropriate declotting/unblocking agent • Cathflo website: http://www.cathflo.com/home/index.jsp Learning Activities Case Study Mrs. J. is a 54 year old woman who has been receiving parenteral nutrition at home through a Bard 9.6 FR single lumen tunneled Hickman catheter which has been insitu for 2 years. The insertion documentation does not indicate the length of the catheter. She reported that over the last few weeks she had increasing resistance while flushing and today she is unable to flush at all. • Identify the most likely cause of the occlusion • What is the most appropriate catheter clearance agent? • Can the indicated unblocking agent be safely used in this type of catheter? If she had a Power PICC Solo would you be able to treat the occlusion? • Can you determine the priming volume of the catheter? • What volume of catheter clearance agent would you use? Learning Activities Case Study Mr. G. has been in hospital for 6 days receiving ampicillin through his #4FR Groshong PICC. Inserted length 42cm, external length 3cm. Today the nurse infused ampicillin just after infusing an incompatible medication and she forgot to flush in between medications. Immediately after she started the pump it showed a downstream occlusion and she was unable to flush the catheter. – Identify the most likely cause of the occlusion – What is the most appropriate catheter clearance agent? – Calculate the lumen volume of the catheter – Write out how the order should be sent to pharmacy – Are there any precautions to consider prior to instilling the unblocking agent? Learning Activities Case Study On PICC rounds you notice that Mr. T’s 5FR dual lumen Groshong PICC has tape around the white lumen and it is labeled “blocked-do not use”. You note blood backed up into the injection cap. The nurse tells you that it has been blocked for about a week, but they only require one lumen so they are not concerned. • Do you agree with the nurse that you should not be concerned? • What are the risks of leaving a lumen blocked? • Considering what you know about the efficacy of Cathflo, if the lumen has been blocked for 1 week, is it worth trying to treat the occlusion? Learning Activities Case Study Your are called to a unit to assess Mrs. C’s PICC. She has a dual lumen 5FR Power PICC Solo. The purple lumen is functioning well but the red lumen is completely occluded. The nurse reports that the red lumen occluded yesterday, shortly after she obtained blood samples from the lumen. Mrs. C. has been on IV cefazolin for 5 days for left leg cellulitis and it is anticipated that she will receive 2 more days of therapy. • What is the most appropriate catheter clearance agent? • Would you instill this agent? Explain your rationale Frequently Asked Questions Frequently Asked Questions Q. What happens if the catheter clearance agent is unsuccessful and you are not able to withdraw it? Can you attempt to flush the catheter? A. The catheter clearance literature recommends withdrawing and discarding catheter clearance agents. However, when catheter clearance has not been effective, this may not be possible. Unless, there is a clinical indication that patient should not receive any of the agent systemically (eg. haematological disorder and Cathflo) you may need to flush the agent in to fully assess the patency of the catheter. If you have any concerns you should review the patient’s situation with his/her physician. Frequently Asked Questions Q. A power PICC solo has had several thrombotic occlusions which have been treated successfully with Cathflo. Flushing and locking technique is appropriate and the tip is positioned in the lower 1/3 of the superior vena cava. Is there anything else that should be tried to prevent further occlusions? A. Some patients may have issues with hyper-coagulation. If your patient’s history indicates that this could be an issue, you may want to discuss with the physician whether a heparin lock or sodium citrate 4% lock should be used to prevent further occlusions. Frequently Asked Questions Q. What if you can’t determine the lumen volume of the catheter and the agent is supposed to be instilled according to the lumen volume? A. In most situations, alteplase is not ordered according to lumen volume. As per monograph, the usual dosage is 2mL. All other agents are ordered according to lumen volume, so prior to proceeding you must discuss with the ordering physician if they want to proceed knowing that some of the agent may be injected into the venous system. Frequently Asked Questions Q. What if you can’t determine the most likely cause of the occlusion? A. If your assessment suggests that it is appropriate to proceed with occlusion management – Cathflo should be the first catheter clearance agent used because the majority of catheter occlusions are thrombotic. Ensure that there are no contraindications to using Cathflo prior to proceeding. Frequently Asked Questions Q. What if you can’t determine what type of implanted port a patient has and the physician has ordered ethyl alcohol to treat a lipid occlusion? A. If you are unable to determine if the catheter is polyurethane or silicone, you cannot proceed with instillation of ethyl alcohol because of the risk of damaging the a polyurethane catheter Frequently Asked Questions Q. Do vital signs need to be taken immediately prior to instilling a catheter clearance agent? A. Baseline vital signs are necessary to rule out such precautions as a catheter related infection. Vital signs also provide baseline data in case of any adverse reaction to the catheter clearance agent. If there are already documented vital signs for the shift, review these and if appropriate proceed with instillation. If there are no vital signs documented for the shift, obtain vital signs prior to instillation.