Procedures that can be accomplished by the generalist or ED personnel include establishing access, performing phlebotomy, and infusing fluids or medications The general procedure for establishing access and patency is similar for both tunneled and totally implanted devices ( Table 135.6 ) Aseptic technique is mandatory Because tincture of iodine solution can damage Silastic catheters, 2% chlorhexidine gluconate or povidone-iodine solution is used to clean the site Recent studies have demonstrated lower bloodstream infection rates with the use of 2% tincture of chlorhexidine and chlorhexidine-impregnated dressings Antimicrobial locks, including ethanol locks, and antibiotic/antifungal locks are often instilled daily in patients with long-term CVCs who have limited venous access and a history of recurrent central line infections, and those who are a highest risk of severe sequelae from an infection Locks dwell from to 24 hours Ethanol locks are highly recommended for at-risk patients, but can only be instilled into silicone catheters due to risk of degradation of polyurethane, in which case, and antibiotic lock may be ordered Clamps or hemostats with teeth should not be used, as these instruments can damage the external portion of the catheter In addition, smaller (less than mL) syringes can generate too much pressure inside the catheter, causing catheter breakage Therefore, 5- or 10-mL syringes are recommended to flush the system; never force flush against resistance Fluid or medications should never be infused until patency is established because the risk of administering these solutions into a nonvascular space is high To prevent air emboli, all clamps must remain closed when any part of the circuit is open For accurate blood test results, the amount of blood that needs to be withdrawn and discarded prior to obtaining a laboratory sample is mL from a tunneled CVC and mL from a totally implanted CVC Recent literature has demonstrated that compared with heparin, tissue-type plasminogen activator (tPA) is more successful in reducing the chances of clot formation in central venous hemodialysis catheters However, further research on other types of catheters and cost analyses remain to be performed to determine if tPA should replace heparin in this regard TABLE 135.6 TIPS FOR THE ROUTINE USE OF INDWELLING VENOUS ACCESS DEVICES Aseptic technique Do not use clamps or hemostats with teeth for external catheters Flush entire intravenous circuit before accessing system Always close clamps when any part of the circuit is open Clean the needleless cap for 15 seconds and allow to dry prior to every entry into the cap Do not infuse fluids or medications until patency is established Flush the catheter/port with 5–10 mL of saline between medications Flush cap or port with heparin when procedure is complete When a tunneled CVC is accessed, these steps should be followed: Before accessing the system, prime the intended IV circuit, including connection tubing, with saline to remove air Clamp the IV tubing closed Clamp any external portions of central catheter on the protected area near the hub Clean the cap on the end of the system using at last 15 seconds of mechanical friction, preferentially with a device, such as Site-Scrub, that contains alcohol, povidone iodine, or chlorhexidine Allow the solution to dry Repeat cap cleaning prior to each entry Flush the system with to mL of saline in a 5- to 10-mL syringe and then aspirate to mL of blood to check patency; not use this as a blood sample —discard Absence of blood return may indicate the formation of fibrin sheath on internal catheter tip or malpositioning of the tip If no blood returns, consider treatment with tPA if a fibrin sheath is suspected If not successful after two doses, consider a dye study and not use the catheter for vesicant infusion Draw off blood needed for laboratory analysis and administer medications or fluids as needed Flush again with saline and then either flush the device with heparin or connect the IV tubing to the needleless cap using Luer lock connections If the catheter is to be heparin-locked, clamp the line prior to removal of the flush syringe; this maneuver is not necessary for the saline-flushed Groshong device If the needleless cap is removed, discard the old needleless cap and replace it with a new one using sterile technique The procedure differs slightly when accessing a totally implanted CVC or port Because intact skin is penetrated, the use of a topical anesthetic cream before access should be considered when feasible After leaving the topical anesthetic on for the manufacturers’ recommended time, it should be wiped off and the skin should be cleansed with 2% chlorhexidine gluconate, alcohol, or povidone-iodine Povidone-iodine should not be cleaned off with alcohol Using a sterile technique, triangulate the port body with three fingers, and insert a Huber needle through the skin directly into the reservoir diaphragm when resistance is met at the back of the reservoir The needle should be secured in place and patency should be confirmed with aspiration and flushing After use, the totally implanted device must be flushed using to mL of heparin (10 units/mL) When the port is not being used, patency is maintained with to mL of 100 units/mL flush on a monthly basis Complications resulting from accessing CVCs include occlusion, air embolus, catheter breakage or displacement, and infection Although most of these complications can be avoided if care is taken to maintain aseptic technique, the clinician should be aware of their diagnosis and management Clinical Findings/Management Catheter Occlusion Difficulty drawing blood or infusing fluid through a CVC can be the result of catheter malposition or occlusion The catheter may be positioned against a vessel wall, or fibrin or blood may clot in the lumen In addition, various precipitates can occlude the lumen of the catheter Waxy precipitates can result when parenteral nutrition solutions contain combinations of fat, protein, and carbohydrate, and particulate precipitates can result from the poor solubility of calcium and phosphorus IV phenytoin (especially when administered in a glucose-containing solution) and diazepam can also precipitate Children who require IV medications or fluids at home may present for shortterm management of catheter occlusions Increasing the venous pressure gradient along the catheter can facilitate phlebotomy These maneuvers include having the patient hold his or her arms above the head, cough or perform Valsalva maneuver, and placing the patient in Trendelenburg position If blood still cannot be drawn, mL of saline should be used to gently irrigate the CVC Never flush against resistance as the pressure can force a clot into the bloodstream or rupture the catheter, particularly if the practitioner uses too much force or too small a syringe Care should be taken to observe the catheter for a balloon “aneurysm,” a sign of impending rupture Totally implanted systems are much less likely to clot than are tunneled catheters This situation is fortunate because irrigating the clot is more difficult to perform on a totally implanted system Specific agents may help dissolve precipitates or clots For waxy precipitates, 70% ethanol should be used For particulate precipitates, 0.1N hydrochloric acid (HCl) or 8.4% sodium bicarbonate should be used depending on the pH of the drugs/solutions infusing prior to the precipitate formation Fibrinolytic agents such as tPA (up to mg, dependent on catheter size) may dissolve a blood clot, and similar to HCl, may be used up to two times in 24 hours if necessary Ethanol should be used only one time per episode tPA infusions may be started at the suggestion of the surgical or interventional radiology consultants, who should be involved in the treatment plan if initial attempts are unsuccessful Air Embolism Failure to maintain a closed system during manipulation of indwelling venous catheters can result in embolism of air into the chambers of the heart Passage of the embolus to the systemic or pulmonary circulation can result in severe and irreversible tissue damage Air embolus can cause a patient to experience sudden onset of tachypnea, tachycardia, hypotension, or loss of consciousness Other diagnoses that should be considered in patients with these symptoms are pneumothorax, liberation of septic emboli, and direct cardiac insult If an air embolus is suspected, the patient should be placed in the left-sided Trendelenburg position and oxygen should be administered In addition, the indwelling catheter should be clamped and remain unused as other peripheral access is obtained Catheter Breakage The family members and physicians caring for the child with a tunneled catheter may have considered the nightmare of catheter breakage and subsequent exsanguination Although catheter breakage is a distinct possibility, most events occur during routine care rather than during playtime and therefore the blood loss is easily apparent and correctable A tunneled catheter can acquire a small hole from inadvertent needle puncture or even ordinary wear and tear Totally implanted catheters, in contrast, are less susceptible to local events or wear and tear However, trauma to the area can result in detachment of the proximal portion of the catheter from the implanted port Leakage of blood or fluid from the externalized portion of a tunneled catheter is easily noticed Externalized catheters must be immediately clamped proximal