The real reasons your IV lines are occluding
Quick tips to stop the problem before it begins
Occluded catheter lines are nothing new to home infusion nurses, and they’re not likely to end any time soon considering there are numerous causes, ranging from anatomical to insertion-related problems. The fact is, however, that there are several causes that are the most prevalent. By using the following tips on preventing occluded lines, it’s likely your agency can significantly reduce the occurrence and enjoy the accompanying benefits of fewer follow-up visits and patient calls as a result.
Lynn Hadaway, MEd, RNC, CRNI, principal of Hadaway and Associates, an infusion therapy consulting firm in Milner, GA, says the problem of occluded lines must be taken seriously.
"I think it’s a significant problem and a very complex issue," she says. "Prevention should always be the ultimate goal because occluded catheters present a significant risk ranging from loss of the catheter to serious infections."
The following are the most common reasons lines become occluded:
• User error.
According to Nina Elledge, RN, CRNI, who does per diem work for home infusion providers as well as serving as president of Castro, CA-based Access Professionals, an infusion therapy consulting firm specializing in pediatrics, this is the most frequent reason for calls from home infusion patients.
"Usually it is user error, where a clamp is on, or the lines are kinked," she says.
• Blood clotting.
It doesn’t take long for the human body to react to a foreign object and begin the clotting process. However, by combining manufacturers’ biocompatibility testing of their products with proper insertion techniques by nurses, blood clotting in the line can be an entirely avoidable problem, says Hadaway. The situation usually arises as a result of user error.
"There are situations where the infusion is completed and it’s not disconnected and flushed quickly enough," she says. "The blood then backs up and clots."
However, technology has increased the incidence of such blood clotting. "Some needleless injection systems tend to allow reflux of blood back into the catheter lumen," notes Hadaway.
By flushing the total solution into the line and then withdrawing the syringe from the injection cap, a dead space is left inside the cap which leads to the reflux of blood. "That blood does not mix with the heparin solution, so over a period of time it builds up a clot that goes from a small, partial occlusion to possibly a complete occlusion."
Eliminating such an incidence of blood clotting simply requires the use of positive pressure flushing techniques that prevent the long-term build-up of such a clot.
Not all patients are created equal, however. Patients in a hypercoaguable state, such as cancer patients, pregnant women, and diabetics, are more prone to clotting and therefore should be monitored closely.
• Chemical reactions.
In particular, drug precipitates and mineral precipitates occur when there is an interaction between two incompatible medications.
"The biggest culprits are things like valium and dilantin, as well as calcium and phosphate in TPN [total parenteral nutrition]," notes Hadaway. She also adds that some professionals forget that heparin is incompatible with numerous drugs including amikacin sulfate, erythromycin lactobionate, gentamicin sulfate, meperidine HCl, methicillin sodium, morphine sulfate, promethazine HCl, tobramycin sulfate, and vancomycin HCl.
But even when flushing a line with a drug incompatible with heparin, using the saline, antibiotic, saline, heparin (SASH) procedure eliminates the problem. "You need the heparin, so you have to flush with saline in between the heparin and the medication on the front end and the back end," she says.
Elledge notes that by working with experienced professionals, drug precipitate problems should be rare. "This is probably the least frequent reason, and that is the result of working with pharmacists who are familiar with infusion pumps, rates, and drug incompatibilities."
But don’t think the problem of occluded lines will always be as cut and dried as one of the three reasons listed above. "It is all these problems rolled into one, such as the venipuncture and catheter advancement techniques, the flushing technique used and the drugs being infused," says Hadaway.
When prevention fails
Even with the best of intentions, you may find yourself dealing with an occluded catheter. Treatment presents a unique problem for home infusion providers. "You’ve got to have the physician’s orders to use these medications to clear out the occlusions," says Hadaway, noting that urokinase is used for blood clots and either hydrochloric acid or sodium bicarbonate is used for a drug precipitate.
It may sound simple enough, but logistics prove to be the big hurdle for home infusion providers when trying to obtain the medication once the nurse is already at the patient’s home.
"If the nurse is 50 miles away from the office and makes an assessment that a dose of urokinase is needed to declot the catheter, even if there is a standing order, the pharmacy has not released a dose of the drug to be in the patient’s home," notes Hadaway. "Because of state pharmacy laws the nurse cannot carry those drugs so the they are is stuck far away from the office without the drug needed to address the situation."
Elledge says it’s important not to put off handling an occluded line. "If a patient calls in and says their line is blocked, deal with the complications immediately," she says. With proper patient education, you’ll likely be able to troubleshoot problems by phone.
Patients should always have 24-hour access to a professional trained in home infusion. They also should be trained in aseptic technique and, most importantly, on proper flushing technique. "Patients must understand that they have to flush the line as soon as the infusion is finished, that they have to flush with saline, followed by heparin, and use positive pressure when flushing," says Hadaway, who notes there are two proper ways to teach positive pressure flushing techniques to patients.
The first is as they’re flushing in the last 1¼2 cc of the solution, to withdraw the syringe from the cap. This fills up the "dead space" with solution and prevents the reflux of blood into the catheter lumen.
However, because valve systems don’t allow this procedure, instead you must hold your thumb on the plunger of the syringe while you close a clamp on the short extension set between the catheter and the hub. In both cases, the presence of continuous positive pressure on the solution prevents the reflux of solution and blood.
Elledge ads that it’s important to allow the patient to demonstrate the flushing procedure on the initial visit so they can get a sense of how the flushing process should feel when done correctly.
With the above training, it makes troubleshooting over the line a simple three-step process.
1. "The first thing that should be done when a patient calls is have them check all the lines and the clamps to make sure the line is open," says Elledge.
2. Next, she has the patient trace the tubing from the pump all the way back to the insertion point of the line and make sure there are no kinks.
3. "Next, with a 10cc syringe I will have them do a gentle attempt at aspiration and then flushing, aspirating first in case there may be a clot in there that they can pull out," says Elledge.
By having a patient flush during their education, the patient can immediately tell if they meet up with more resistance than they should.
"I make it a real strong point during training to tell patients that if they have any problems with the line – If it feels different than it does now’ then you call us and don’t do anything," she says.
If none of the above steps work, Elledge instructs the patient to stop the infusion and, if applicable, clamp the line. If possible, a nurse is sent out to troubleshoot the line. If not, the patient is told to call his or her doctor.
There’s some debate on whether use of midclavicular tip location increases the likelihood of blood clotting. Hadaway takes the position that it does, and notes that there is a growing number of studies that supports her position.
"The biggest problem in home care is the use of the midclavicular tip location," she says. "When you put the catheter tip in the midclavicular region, the clot begins inside the vein and it can propigate into the catheter lumen. There is a tremendous amount of clinical research that shows the complications associated with midclavicular tip location. Although tip placement in the superior vena cava does not totally eliminate the problem, it drastically reduces it."
Elledge disagrees. "In my experience in the field, I just haven’t seen that," she says. "There is literature that says there are problems with midclavicular tip placements, but you have to look at the big picture. How many of these lines have been placed, and how many of these lines result in thrombosis that cannot be treated by declotting agents: I believe that percentage is small."
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