Can the kidney community make it safer for patients to self-dialyze? Debbie Brouwer Maier, a hemodialysis nurse and long-time Transonic employee, says the issue is deeper than it looks. When Debbie says a topic merits discussion, we sit up and listen, because overstatement does not apply to Debbie’s credentials. She recently testified for a Congressional Hill briefing about hemodialysis VND and ABLS risk, if that tells you anything…
In truth, this query has been rumbling around for a while, and it’s pulling a storm across the hemodialysis horizon. It has put some clinicians at odds with patients, kept insurance agents awake at night, and called enough government regulations into question that the FDA has weighed in. The waters have been muddied further by the financial momentum of facility-based dialysis, and as with any subject that involves big money and big corporations, an unbiased opinion can be elusive. Fortunately, at Transonic, we have Debbie to set the record straight. In a recent phone call with the Editor, Debbie explained that many nephrologists are hesitating, and for good reasons.
Hemodialysis has been engineered as a two-person process, i.e., the machines are designed to be operated by someone who has unencumbered, standing access to the device, not by someone sitting in an easy chair, partially immobilized by a needle in their arm. The needle itself poses more problems. If the patient isn’t at a facility, who is going to insert it? The patient has only one available hand. The same applies for removal. To extract their own needle, a patient must perform an awkward “press-with-one-hand-while-sliding-the-other” maneuver. Taping the needle securely adds another layer of complication.
But the patients argue back. They claim they’re more comfortable in their own home, and who would disagree? More importantly, they insist they feel safer at home because they are safer. We all know that dialysis staff are well-meaning, but that they are also overworked. Why, patients ask, should they place their life in the hands of a person who is trying to care for twenty other patients at the same time? Should their treatment only receive 5% of someone else’s attention when it could receive 100% of their own or their care partner’s? Ironically, COVID casts its vote with the patients, since they are far less likely to be infected in their own house than in a packed clinic.
But many nephrologists don’t agree. Dialysis is a draining procedure (no pun intended) and patients often fall asleep during treatment. So, what happens when a sleeping patient accidentally dislodges their own needle? (This occurs with alarming regularity.) The patient’s precious lifeblood drains out at such a rate that even a trained clinician would have only 1-3 minutes to save the patient’s life. Even if a home-patient did awaken, say, at minute 2, they would not have the equipment, nor at that point of blood loss, perhaps even the cognizance to help themselves.
And with that thought, Debbie brought us to the crux of the matter: Venous Needle Disconnect. Broadly, a hemodialysis machine has two “sides:” arterial (withdraw) and venous (infusion). If the arterial needle dislodges, air will be pulled into the lines, causing them to collapse, which in turn causes a pressure change. Even if the pressure monitor doesn’t respond, the air won’t pass the detector before the machine automatically shuts down.
The venous side, however, operates under positive pressure, so if the needle dislodges, no air is inducted to set off the alarm. Furthermore, the needle has to land somewhere (the patient’s clothing, a blanket, the chair) which usually creates additional resistance. In short, the resulting change in pressure is so miniscule that if the monitor were set up to detect it, the alarm would sound every time the patient squirmed.
“Fortunately,” Debbie concluded, “Pressure isn’t the only metric.” When a venous needle dislodges, there is a brief moment of low-restriction flow before it lands. We all know a company that specializes in cutting-edge flow-measurement equipment. A Transonic flow sensor, built into a hemodialysis machine, could shut down the pump the moment the needle slips free. With the right OEM partner, Transonic’s technology could relieve doctor’s worries about exsanguination, allow patients to return home, let insurance agents rest easy, and assure the FDA that patients are being properly safeguarded.
And in modern medicine, a solution that pleases everyone is a minor miracle.
But that’s what we do at Transonic.
