Standards and Recommendations relating to the prevention and detection of Venous Needle Dislodgement
This document deals with how the risk of venous needle dislodgement is treated in International, US and European Medical Standards as well as in the medical literature.
In all sets of standards, it is acknowledged that venous needle dislodgement can cause potentially lethal situations and that there is currently no optimal system available for detection.
Various organizations and other sources confirm the lack of an optimal alarm, adding proof of incidents where an adequate alarm could have changed the fatal course of events. Redsense is the first clinically tested monitoring system for venous needle dislodgement in hemodialysis.
Venous Pressure Monitoring: Acceptable But Not Optimal
The International Standard for Medical Electrical Equipment/Haemodialysis(1) states that: “Monitoring of the venous pressure is not always suitable for detecting a blood loss in time, in case the venous puncture cannula slips out. The venous pressure is determined mainly by the hydraulic resistance of the venous puncture cannula, particularly with today’s usual high blood flow rates of up to 500 ml/min. A venous pressure alarm is, hence, not able to always detect whether or not the puncture cannula slips out”.
This standard also mentions that “most reported cases of fatal blood loss are caused by blood access cannulas slipping from the fistula or graft and that “this cannot be prevented by the Haemodialysis equipment”.
According to the American National Standard for Hemodialysis Systems(2) the dialysis machines must be equipped with venous pressure monitoring. However, here it is also acknowledged that this method is not optimal for detecting venous needle dislodgement: “Blood line separation or needle pullout is uncommon but does occur, and can cause potentially lethal situations enabling a -- significant blood loss from venous disconnection. No system in current use will reliably detect such a venous separation or needle pullout”.(3)
Safety Even More Important in Home Dialysis
The International Standard for Medical Electrical Equipment/Haemodialysis4 states that “if staff is not present (e.g. home patient) or delayed for a long period in the case of venous puncture cannula slippage, the blood loss from the venous access (backwards) may become hazardous to the patient.
Nocturnal Home Hemodialysis (NHHD) takes place in the home while the patient is sleeping, typically at night, up to seven times per week, for approximately six to ten hours per treatment. It is administered by the patient or a trained partner, rather than by a trained medical professional.
According to FDA guidelines(5), in NHHD; “safety becomes a primary concern” and:“Any device malfunction, access problems, or break in the seal of the hemodialysis circuit (e.g., dislodged access needle, blood leaks) would be life threatening, even with the lower blood flows used in nocturnal home hemodialysis.”
These guidelines recommend alarms to detect fluid (blood or
dialysate) leaks, and a moisture detector (until now, the only
alternative detection method) at the site of hemodialysis access.
Note: the
Redsense alarm is
approved for use
in home-hemodialysis in
Europe & worldwide. However, in the USA,
The
Redsense device is
intended to monitor for potential blood loss from the hemodialysis
access site in the clinical setting only.
Venous Pressure Monitoring and Needle Dislodgement
In 1998, the ECRI Institute(6) received
two reports of hemodialysis machine venous line needles dislodging from
patients during treatment without triggering a venous pressure alarm.
Their conclusion:
“ECRI believes that the venous pressure monitor is not a
reliable means of detecting needle dislodgments and agrees with
manufacturers that visually monitoring the status of blood lines appears
to be the only sure way to spot these problems.”(7)
Instances in which the venous pressure alarm may not activate are
described in an article from 2006.(8) These instances are confirmed by
reports of incidents from the MAUDE Database(9):
1. If the venous pressure alarm limit is not properly set. Even complete
disconnections of blood lines from catheters or cannulas resulting in
total loss of the extracorporeal blood flow may go undetected. (MAUDE
515860)
2.
Even with properly set alarm limits, the venous pressure monitor may not
alarm if the venous cannula slips from the fistula or graft, which may
happen if the cannula is not properly fixated. (MAUDE 557216)
Measuring fistula pressure to identify patients at risk
HD Polaschegg10 has showed that fistula pressure is crucial if you want
to identify high-risk patients for venous needle dislodgement. Whilst
low fistula pressure is optimal for many reasons, the venous pressure
monitor is unlikely to detect needle dislodgement if the fistula
pressure is below 25 mmHg.
He recommends that venous fistula pressure is measured before treatment,
and that if fistula pressure is below 25 mmHg, the patient should be
regarded as “high risk patient”. According to him, low fistula pressure
may be present with more than fifty percent of the patients and
recommends:
“For patients with low fistula pressure, i.e .the majority of patients,
use external devices or other measures”
Risk Reduction & Intended Use
The European Council Directive concerning medical devices11 state that manufacturers must – when a risk cannot be eliminated or reduced – take adequate protection measures including alarms if necessary. The manufacturer must also inform users of the residual risks due to any shortcomings of the protection measures adopted.
Risk Reduction also includes ensuring that any equipment, disposables
or systems in dialysis is used according to its Intended Use. For
example, moisture detectors such as enuresis pads are sometime used to
detect needle disconnections during hemodialysis though it is not their
intended use. In some countries, for example in Germany, according to
the guidelines on Safe Application of Medical Devices(12),
using devices outside of “intended use” may have serious consequences:
“If a clinic, knowingly or unknowingly, uses devices or disposables that
are not approved, this is considered to be Non-Intended Use. In such
cases, the organization bears the responsibility for any resulting
damage.”
For matters related to product specifications, contact the
manufacturer:
CEO Patrik Byhmer
+ 46 (0)35 10 60 30
E-mail: patrik.byhmer@redsensemedical.com
1 International Standard, IEC 60601-2-16 ed 3.0 Copyright © 2008 IEC, Geneva, Switzerland. www.iec.ch
2 AANSI/AAMI RD5:2003
3 AANSI/AAMI RD5:2003, Section A.4.2.4.1, General
4 International Standard, IEC 60601-2-16 ed 3.0
Copyright © 2008 IEC, Geneva, Switzerland. www.iec.ch
5 On June 8, 2003, The Medical devices advisory committee held an open
public hearing for the purposes of evaluating devices and guidelines for
nocturnal home dialysis
6 An independent international organization focusing on medical device
safety:www.ecri.org
7 Undetected Venous Line Needle Dislodgment during Hemodialysis, Health
Devices Nov 1998;27(11):404-6
8 Neglected Safety Aspects in Hemodialysis and Their Related Problems,
H-D Polaschegg, Hemodialysis Horizons, AAMI, 2006
9 MAUDE: Manufacturer and User Facility Device Experience Database,
hosted by FDA/US. MAUDE data represents reports of adverse events
involving medical devices
10 EDTNA/ERCA Conference, Prague, September 2008,
Seminar, Hans-Dietrich Polaschegg: “Venous needle dislodgement: A safety
issue. Possible methods for detection and prevention of major blood
loss”
11 93/42 EEC, from 14 June 1993
12 Principles for Safe Application of Medical Devices in Extracorporeal
Renal Replacement Therapy, Deuthsche Norm VDE 0753-4
Credit and disclaimer: Excerpts from International Electrotechnical Commission (IEC) for permission to reproduce information from its International Standard IEC 60601-2-16 ed.3.0 (2008). All such extracts are copyright of IEC, Geneva, Switzerland. All rights reserved. Further information on the IEC is available from www.iec.ch. IEC has no responsibility for the placement and context in which the extracts and contents are reproduced by the author, nor is IEC in anyway responsible for the other content or accuracy therein.