Reducing risks of tourniquets left on after finger and toe surgery: summary of a safety report from the National Patient Safety Agency
BMJ 2010; 340 doi: https://doi.org/10.1136/bmj.c1981 (Published 21 April 2010) Cite this as: BMJ 2010;340:c1981
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Whilst we agree with the overall message in the NPSA report [1]
(including BMJ summary [2]) highlighting the risks associated with digital
tourniquets and the need for regulation, we wish to reiterate the views of
previous responders and expand with our own concerns relating to the
publication.
We believe there should be a greater focus on the process rather than
non-evidence-based products. The process of checking digital tourniquets
is fundamentally more important than the type of tourniquet used. Using
bold text in the NPSA briefing sheet has placed an overemphasis on product
over process. Imposing a new and unfamiliar product into a surgical
procedure without established safety mechanisms has the potential to cause
greater harm than no change at all.
We are aware of one near-miss incident in Devon following the
introduction of new unfamiliar CE marked digital tourniquets, as
recommended by NPSA guidance this year. A patient was discharged with a
finger tourniquet in situ but was fortunately called back by the surgeon
involved after doubts arose a few hours post-procedure. This compares with
only one incident (anecdotally) in the last fifteen years from the same
region. If this can occur in a controlled environment, we are concerned
about the increased possibility in busy emergency departments or community
practices.
We agree with the concerns of Choudhury and Malhas [3] relating to
the geographical locations where digital tourniquets are commonly used.
More importantly, we feel there is a greater danger if unfamiliar CE
marked digital tourniquets are used in the community, general practice,
podiatry clinics and emergency departments without access to or the
ability to carry out two-person checklists such as a modified WHO surgical
checklist, swab checks and "time-outs". The latest rapid response from the
NPSA [4] shows that thought has been given to this issue but
disappointingly gives no indication of any suggested procedural changes
for busy, understaffed departments.
There are CE marked digital tourniquets that are clearly not fit for
intended purpose (Figure 1). The tourniquets can be skin/pastel coloured
and although designed for safety some have a paper label which can be
easily torn off especially when wet. In addition, there is little
instructional documentation available on packaging to enable accurate
sizing; this may be exerting unacceptably high pressures on digital nerves
deep to the tourniquet.
Surgeons are trained to innovate where necessary and continue to do
so in many areas of practice with various unlicensed products, featuring
widely in many technical note publications worldwide providing ever
expanding and improving evidence with which to base modern practice -
again, the NPSA has briefly mentioned a few techniques but whilst clearly
recognising that there is a lack of evidence they have chosen to promote
only "intended for use" CE marked tourniquets. Would the authors complain
if life saving chest decompression for tension pneumothorax was carried
out (as is standard) using a non-licensed intravenous cannula?
With respect to the use of gloves there is published evidence
demonstrating that the pressures are acceptable [5]. Additionally, there
are a range of sizes available and assessment of required sizes is much
easier than with many CE marked tourniquets. Irrespective of tourniquet
type, we have considered safety issues and recommend the use of bright
colours and attachment of an artery clip.
In addition to the above, we are disappointed with the one-sided
nature of the NPSA report, briefing sheet and poster resource they have
provided. The intention to promote safe use is clearly evident however
this is overshadowed by an over-emphasised message that the main point of
the alert is to prevent the use of gloves. In the briefing sheet the
authors quote 15 serious incidents between 2005 and 2009 however the main
report states that a search was actually carried out from with RLS
(Reporting and Learning System) data between 2003 and 2009. This simple
omission significantly alters the incidence, adding bias to the argument.
The literature review provided in the NPSA report is also biased towards
evidence for harm and fails to expand on a number of studies showing
evidence of pressure studies including the study by Naim et al [6] cited
by Barai et al [7] in their rapid response. The authors might be
interested to read one of a series of BMJ correspondences in 1973 which
refers to the use of clear commercially available tourniquets as the focus
of litigation [8] - will events repeat themselves with poor CE marked
tourniquets?
In summary, we believe that rapid change to surgical practice and
equipment has the potential to cause significant harm if applied without
due thought to the process. Emphasis on reduction of litigation by making
the main message "Surgical gloves are not to be used as tourniquets" [1]
has taken the focus off the real issue which is the need for due
consideration of the process involved. We would argue that a safer alert
would have been provided if the main message was "Do you have an adequate
system in place to ensure finger tourniquets are always removed?" We would
propose that better guidelines would be: 1. Always use bright coloured
materials and 2. Apply a clip from the set, even if a CE marked tourniquet
is used. These guidelines ensure safety when used with sensible changes to
the process. The current guidelines have lead to a false sense of security
in theatres where they think they are now complying simply because they no
longer use gloves.
References
1. Rapid Response Report NPSA/2009/RRR007: Reducing risks of
tourniquets left on after finger and toe surgery. National Patient Safety
Agency. December 2009.
2. Lamont T, Watts F, Stanley J, Scarpello J, Panesar S. Reducing
risks of tourniquets left on after finger and toe surgery: summary of a
safety report from the National Patient Safety Agency BMJ 2010;340:c1981,
doi: 10.1136/bmj.c1981 (Published 21 April 2010)
3. Choudhury M, Malhas A. Where (geographically) is the tourniquet
being applied?? BMJ (Published 13 May 2010)
4. Lamont TJ, Watts F, Panesar S. Safer practice with digital
tourniquets. BMJ (Published 22 October 2010)
5. Hixson FP, Shafiroff BB, Werner FW, Palmer AK. Digital
tourniquets:
a pressure study with clinical relevance. J Hand Surg [Am]
1986;11(6):865-8.
6. Naim S, Srinivasan MS. Digital tourniquets: a comparative analysis
of pressures and pain perception. Acta Orthop Belg. 2008 Apr;74(2):195-9
7. Barai K, Jain R, Srinivasan M. Does evidence confirm CE marked
digital tourniquets are safer? BMJ (Published 3 May 2010)
8. Hoare E. Simple Finger Tourniquet. Br Med J. 1973 August 4;
3(5874): 293.
Competing interests: No competing interests
From the authors:
We were interested in responses received since publication of our
piece on retained digital tourniquets, based on a safety alert issued in
December 2009. It is heartening that 95% of eligible trusts (264/277) now
report compliance with the actions in this alert .
The particular point raised by Choudhury and Malhras concerned risks
outside operating theatres. We wholeheartedly agree with this. As noted,
almost half of the (small number) of reported incidents came from
emergency departments and settings outside hospitals, such as podiatry
clinics, and we know there is substantial under-reporting. One of the
explicit aims of the guidance was to raise awareness and transfer routine
checks from surgical practice (counting and recording on-off times of
tourniquets as part of swab and instrument counts) to other settings.
This is true of other safety alerts issued by the NPSA - for instance,
applying swab counts (routine perioperative practice for caesarian
deliveries) to the setting of normal births to prevent retained vaginal
swabs. In the words of another respondent (Fitchett) on that issue,
"context sometimes blinds us to best practice."
We agree with Barai et al that there is a lack of evidence on the
effectiveness of different types of tourniquet and the Naim study is an
interesting addition to this. Although your findings appear to suggest
surgical gloves can achieve good digital pressure compared with commercial
tourniquets or urinary catheters, artery clips are still needed to prevent
the glove being accidentally left on. This contravenes the safety
principle, enshrined in regulation, of devices being used for their
intended purpose only. We believe that right sized commercial tourniquets
can achieve adequate titration and are designed for that use. We are also
aware that more commercial tourniquets are now on the market than at the
time of testing for the Naim paper some years ago.
It is worth reminding ourselves that this safety alert was issued in
response to serious incidents in which tourniquets (of whatever form) had
been left on by mistake, resulting in loss of digits. Our actions
included checks to monitor and remove touniquets (recording on/off time)
and using only purpose-designed, coloured devices. We share Barai's
belief that these incidents can be prevented by simple checks led by the
surgeon to prevent harm, as set out in our guidance.
Competing interests: No competing interests
The work by Lamont et al raises valid concerns about the use of
extremity
tourniquets, issuing the guidelines(1) from which the summary of the
immediate response document(2) was drawn:
"1. Guidelines include the removal of digital tourniquets as part of
the swab
counting procedure and specify the need to record the length of time a
tourniquet is in place.
3. The WHO Surgical Safety Checklist is reviewed locally to consider
adding
tourniquet removal at ‘Sign Out’ stage"
While the focus of the alert appears to be the operating theatre, 6
of 15
incidents occurred outwith the operating theatre environment where to our
knowledge no rigidly structured swab or instrument count would routinely
take place. This perhaps misses almost 50% of such incidents. Furthermore
we would venture that the actual incidence of these complications in terms
of
absolute percentage would be higher in the non-operating theatre setting,
for example a busy Emergency Department.
The technique described by Smith et al(3) is extremely reliable,
though as far
as we are aware evidence for its efficacy is anecdotal, though the final
points
made by Lamont et al- checking perfusion post op and being aware of
complications are merely good practice rather than evidence based.
Additionally one of the outcome measures appears to relate to the
increase in
purchasing of CE marked tourniquets, which does not necessarily equate to
their increased use!
While we applaud this work we feel that perhaps equal focus needs to
be put
on other areas outside the operating theatre where such tourniquets are
used.
References:
1. http://www.nrls.npsa.nhs.uk/resources/?entryid45=65568
2. Lamont T, Watts F, Stanley J, Scarpello J, Panesar S. Reducing
risks of
tourniquets left on after finger and toe surgery: summary of a safety
report
from the National Patient Safety Agency BMJ 2010;340:c1981, doi:
10.1136/bmj.c1981
3.Smith IM, Austin OM, Knight SL. A simple and fail safe method for
digital
tourniquet. J Hand Surg 2002;27:363-4
Competing interests:
None declared
Competing interests: No competing interests
We read with interest the recent Rapid Response Report ‘Reducing
risks of tourniquets left on after finger and toe surgery’, issued by the
National Patient Safety Agency, and applaud its intentions [1]. In
reference to advice advocating the use of only CE marked digital
tourniquets, we would like to draw your attention to a recent study
conducted by our team, its conclusions authored by Naim & Srinivasan
[2].
Through an objective comparison of digital pressures applied by three
different tourniquets types, we concluded the rubber glove tourniquet
subjected the lowest mean pressure to the digit neurovascular bundle (mean
pressure differences were statistically significant). Commercially
available band tourniquets and Foley urinary catheters made up the
comparators and pressures were measured on a sample of 20 healthy
volunteers by utilising specifically designed apparatus to acquire direct
pressure measurements. The band tourniquet was applied as per
manufacturer’s recommendations.
Undoubtedly past case reports underline harm potentially inflicted by
tourniquets when used in a negligent fashion; indeed succumbing a patient
to a digit amputation is a travesty in duty of care. Therefore these are
important considerations. Nevertheless our study demonstrates that
specifically designed, CE approved tourniquets may not always equate to
optimised management.
The Rapid Response Report further references a concern made by the
Pennsylvania Patient Safety authority about the visibility of tan-coloured
tourniquets [2]. Lamont & colleagues offer reference to the use of
coloured gloves, often utilised as an underglove in double gloving
technique, and this is a viable alternative [3].
Our intentions in this response were to inform you of our recent
investigations, given the scarcity of published evidence otherwise. We
believe our study provides reasoned conclusions favouring use of glove
tourniquets. From our literature searches, we are led to believe our
comparative study provides a high level of evidence, in accordance with
accepted standards of grading, and therefore warrants consideration as
well [4].
It is critical for the surgeon in charge to ensure that the time
finger tourniquet was applied and released is documented, and
fundamentally his/her responsibility to maintain a vigilant approach
otherwise. In turn may we propose that the choice of tourniquet
application remain at the surgeon’s discretion, in light of their
experience and coupled with recent published evidence, thereby upholding
to principles of evidence based practice?
References
1.Rapid Response Report NPSA/2009/RRR007: Reducing risks of
tourniquets left on after finger and toe surgery. National Patient Safety
Agency. December 2009.
2.Naim S, Srinivasan MS. Digital tourniquets: a comparative analysis
of pressures and pain perception. Acta Orthop Belg. 2008 Apr;74(2):195-9
3.Lamont T, Watts F, Stanley J, Scarpello J, Panesar S. Reducing
risks of tourniquets left on after finger and toe surgery: summary of a
safety report from the National Patient Safety Agency BMJ 2010;340:c1981,
doi: 10.1136/bmj.c1981 (Published 21 April 2010)
4.CEBM Levels of Evidence. Updated March 2009.
http://www.cebm.net/index.aspx?o=1025. accessed 18/03/2010
Competing interests:
None declared
Competing interests: No competing interests
Re: Reducing risks of tourniquets left on after finger and toe surgery: summary of a safety report from the National Patient Safety Agency
Reducing the Risk of Digital Tourniquets: Product and Process
William Green, M.D., Fellow of the American College of Emergency Physicians
I read the recommendations of the Rapid Response Report and the comments that have since been contributed. Together, the report and responses highlight the two significant risks associated with digital tourniquets: necrosis due to a retained tourniquet and injury due to excessive tourniquet pressure.
I applaud the work of Naim and Srinivasan regarding digital tourniquet pressures (1). In their comments regarding this article, Barai et al (2) suggest the use of glove tourniquets may be favored compared to CE marked tourniquets, based on the comparative pressure being more acceptable. Humphry et al (3) also acknowledge the risks of “unacceptably high pressures on the digital nerves” if an accurate size tourniquet is not used. These comments highlight the less dramatic, but more common complication of the use of digital tourniquets –neurovascular injury secondary to excessive pressure.
The recommended pressure for any upper extremity tourniquet is 200 mmHg (4), the “not to exceed" pressure is 300 mm Hg (5), and nerve injury occurs at 500 mm Hg (6). In Naim and Srinivasan’s study, the glove method applied an average pressure to the digit of 561mm Hg, the elastic catheter 834mmHg, and the commercial silicon band 636 mmHg. While Barai et al are correct that the glove applied the lowest pressures, all methods exceeded the pressure known to cause nerve injury. It would be considered negligent to use pressures of this magnitude when using a pneumatic tourniquet on an extremity, why are we comfortable with the use of such pressures on digits? These pressures are not only excessive, they are unnecessary- pressures of 150 mm Hg are noted to be “very adequate” to achieve hemostasis for a digit (7).
Pressure related injuries may occur quickly; reports note neurovascular injuries after 20 minutes of tourniquet application (8). Two studies performed using methods similar to current digital tourniquets reported tourniquet-induced nerve injury in 71% (9) and 77% (10) of patients. McEwen and Casey note that elastic bands, rolls and straps similar to current digital tourniquet methods apply substantially higher pressures than pneumatic tourniquets and warn that their use may increase the incidence of injury and unnecessarily expose the user to potential legal liability (11).
The inability of traditional methods to reliably apply a safe pressure and their potential to be forgotten on a digit led to the development of the T-Ring, a one size fits all tourniquet that adjusts to any digit size, eliminating the risk of excessive pressure. A recent study by Lahham showed the T-Ring applied a very consistent pressure (149 – 165 mm Hg) on all digit sizes (12). Unlike other methods, the T-Ring did not have to be correctly sized, and in every case it applied the lowest pressure of all methods (surgical glove, Penrose drain, Tourni-cot), while consistently preventing digital blood flow. The T-Ring is also the most conspicuous method; extending 14 mm from the digit, compared to 2 mm for the glove and 3-4 mm for the commercial bands (Tourni-cot, Toe-niquet).
The response by Humphry et al, The danger with finger tourniquets: Product or Process? (3), notes that “there are CE marked digital tourniquets that are clearly not fit for intended purpose”, because they are inconspicuous, have been left on digits and may apply excessive pressure if incorrectly sized. Unfortunately, these risks are associated with all traditionally used digital tourniquets. There are numerous reports of commercial bands and gloves being left on digits, and Naim’s study demonstrates that commercial bands, gloves and elastic catheters apply excessive pressure even when correctly sized. Humphry et al do note that glove tourniquets may apply pressures that are acceptable (13); however, the same study found pressures of 630 mm Hg if a glove one half size too small was used. Additionally, while applying an artery clip will reduce the risk of leaving a tourniquet on a digit, this technique significantly increases the pressure applied to the digit (12). The recent case report (14) by Selvan et al demonstrates that applying a high profile instrument like an artery clip to a low profile tourniquet does not insure that the tourniquet will be removed. A better solution is to use a tourniquet that is conspicuous in it is own right.
In attempting to manage digital tourniquet risks, the following must be acknowledged:
1) there is an inability to monitor the tourniquet pressure
2) traditional methods generate pressures that are highly variable,
excessive and dependent on the application method
3) the least amount of pressure necessary to achieve hemostasis must be used
4) a conspicuous tourniquet must be used
While there are numerous references in the literature that note the above, these points are inherently obvious. If we want to minimize digital tourniquet complications, we cannot continue to justify the use of makeshift methods and commercial devices that have been left on digits and shown to apply excessive pressure.
Finally, there are two reasons that following a safe tourniquet process alone will not sufficiently reduce tourniquet complications. First, while the process will help minimize the risk of prolonged application time and a forgotten tourniquet, it will do little to reduce the risk of neurovascular injury resulting from excessive pressures. Secondly, there will always be a greater risk of complications outside the operating theater, where the process is less familiar, the staffing stretched, the environment is chaotic, and patients with conditions that make them susceptible to injury from excessive tourniquet pressures have not always been identified. While a process will certainly help, there will be a higher rate of process neglect in these less controlled settings. If we want to minimize the risk of digit necrosis from a retained tourniquet or injury related to excessive pressure, a process of tourniquet use needs to be followed. More importantly, however, providers must use a highly conspicuous tourniquet that applies a safe and effective pressure with each application, regardless of the user, the size of the digit or method of application.
1. Naim S, Srinivasan M. Digital tourniquets: a comparative analysis of pressures and pain. Acta Orthop. Belg.2008:74:195-9
2. Barai K, Jain R, Srinivasan M. Does evidence confirm CE marked digital tourniquets are safer? BMJ 3 May 2010
3. Humphry S, Tucker S, Watts A. The danger with finger tourniquets: Product or Process? BMJ 15 Dec 2010
4. Tejwani N, Immerman I, Achan, P et al. Tourniquet pressure: the gulf between science and Practice. J of Trauma. 2006;61:1415-8
5. Sanders R. The tourniquet, instrument or weapon? Hand. 1973;
5(2):119-23.
6. Ochoa J, Fowler TJ, Gilliatt RW. Anatomical changes in peripheral nerves compressed by a pneumatic tourniquet. J Anat 1972: 113 (Pt3): 433-55.
7. Shaw JA, Demuth WW, Gillespy AW. Guidelines for the use of digital tourniquets based on physiologic pressure measurements.
J of Bone and Joint Surg. 1985:67A:1086-90.
8. Dove A and Clifford R. Ischemia after use of finger tourniquet. BritishMed Journal. 1982:284 :1162-3.
9. Dobner JJ, Nitz AJ. Postmeniscectomy tourniquet palsy and functional sequelae. Am J Sports Med. 1982;10:211-4.
10. Nitz AJ, Dobner JJ. Upper extremity tourniquet effects in carpal tunnel release. J Hand Surg Am. 1989;14:499-504.
11. McEwen J, Casey V. Measurement of hazardous pressure levels and gradients produced on human limbs by non-pneumatic tourniquets. In: Proceedings of the 32nd Conference of the
Canadian Med. and Bio Engineering Society 2009. Calgary, Canada; 2009 May 20-22. p 1-4.
12. Lahham S, Tu K, Tran V, et al. Comparison of pressures applied by digital tourniquets in the emergency department. West J Emerg Med 2011 May: 12(2):242-9
13. Hixson P, Shafiroff B, Werner F, et al. Digital tourniquets: a pressure study with clinical relevance. J Hand Surg. 1986:11(6):865-8.
14. Selvan D, Harle D, Fischer J. Beware of finger tourniquets: A case report and update by the National Patient Safety Agency.
Acta Orthop. Belg., 2011 Vol 77: 15-17
Competing interests: Dr. William Green is the Inventor of "The T-Ring", a CE marked, sterile tourniquet for digits manufactured in USA