Archive for June, 2011

Tourniquet Safety: Which tourniquet cuffs can be reused safely, and how?

Posted on June 24, 2011. Filed under: Disposable Cuffs, Reprocessing, Reusable Cuffs, Tourniquet Safety |

Some tourniquet cuffs are designed and manufactured to be reusable in multiple surgeries and their reuse is authorized by the manufacturer. Limited guidance on cleaning, reprocessing, testing and evaluation of reusable cuffs may be provided by the manufacturer, but there is a general need for improvement and more guidance for users.

Other types of tourniquet cuffs are designed manufactured to be safely used as single-use, sterile disposable tourniquet cuffs, and their reprocessing and reuse is not authorized by the manufacturer.

Some general recommendations about tourniquet cuff safety are given in the AORN Recommended Practices for Use of the Pneumatic Tourniquet. [1] Published literature provides still further guidance, eg [2-9].

The current (2009) AORN Recommended Practices (RPs) are in need of updating regarding tourniquet cuff safety, tourniquet cuff reuse and tourniquet cuff reprocessing. For example:

1. For single-use disposable tourniquet cuffs, the RPs do not indicate the hazards to the patient that may be associated with unauthorized reprocessing and inadequate testing of disposable cuffs after reprocessing and prior to any reuse.

2. For reusable tourniquet cuffs, the RPs do not provide recommendations on what type of testing of reusable cuffs should be performed after cleaning and before reuse.

3. For both reusable and single-use disposable tourniquet cuffs, the RPs do not recommend how the results of cuff testing and inspection should be documented and evaluated after cleaning and before any reuse.

4. In current RPs such as those excerpted below, it is not clear which recommendations are meant to include tourniquet cuffs as well as tourniquet instruments.

Relevant excerpts from the current (2009) AORN RPs are given below:

Recommended Practice II: The pneumatic tourniquet and its accessories should be inspected, tested and maintained according to manufacturers’ written instructions.

6. Before each use, the entire tourniquet system should be checked. The cuff and tubing should be inspected for cracks, leaks, and the security of the closure mechanism. Unintentional pressure loss can result from loose tubing connectors, deteriorated tubing, or cuff bladder leaks, and may result in patient injury.

Recommended Practice XIV: The pneumatic tourniquet and accessories should be cleaned after each use.

4. Single-use cuffs should be discarded in an appropriate receptacle.

Recommended Practice XVII: Policies and procedures for pneumatic tourniquets should be developed, reviewed periodically, revised as necessary, and readily available in the practice setting.

1. Policies and procedures for the pneumatic tourniquet should include, but are not limited to:
– safety features required on pneumatic tourniquets;
– equipment maintenance programs; supplemental safety monitors required;
– equipment checks before initial use;
– reporting and impounding malfunctioning equipment;
– preoperative, intraoperative, and postoperative patient assessments;
– responsibility for cuff application;
– precautions during use;
– reporting of injuries;
– potential adverse events;
– care and cleaning of the tourniquet after use; and
– documentation.

2. The frequency, method, and criteria for pneumatic tourniquet testing should be established according to manufacturers’ written instructions. A pneumatic tourniquet management program assists in identifying equipment problems that may have adverse effects on patient safety.


Recommendations Regarding Future Guidelines

The following recommendations for guidelines, based on published literature (eg [2-9]) and manufacturers’ recommendations as available, as well as the current AORN RPs [1], would better reflect current practices and would improve tourniquet cuff safety and effectiveness.


1. For patient safety and for facility risk management purposes, establishment of a tourniquet cuff testing program is recommended, so that each cuff is thoroughly tested according to a written protocol after each use, and prior to the next use, with the results thoroughly documented. (Some modern tourniquet instruments allow this to be done automatically.[10])

2. For each reusable tourniquet cuff, it is recommended that the cuff have a unique identifier, that the number of reuse cycles be recorded, and that the cuff be thoroughly tested on a regular basis by qualified personnel, with results documented and evaluated.

3. For reusable cuffs used in certain procedures, eg IVRA or Bier block anesthesia, it is further recommended that consideration be given to replacing the cuff after a maximum number of reuse cycles is reached, to reduce the risk of cuff failure and patient injuries during use.

4. It is recommended that the tourniquet cuff testing protocol be established in accordance with the recommendations of the original manufacturer of the cuff. At a minimum, a cuff testing protocol should include:

(a) a leak test, including inflating the cuff to a maximum pressure recommended by the manufacturer for a period of time, with the cuff wrapped around a test mandrel or laid flat,

(b) a fastener integrity test, to assure that the fasteners are not degraded to the point of being unsafe at the maximum pressure specified by the manufacturer,

(c) a physical inspection of the cuff to detect blockages of the pneumatic passageway in any portion of the inflatable bladder or tubing due to reprocessing damage or fluid entry,

(d) a visual inspection of the cuff to detect damage or deterioration, including: any warping of stiffener due to inappropriate reprocessing; discolouration or contamination of the cuff surface; damage or deterioration of the cuff connector or inflatable portion; and

(e) written documentation and evaluation of the test results before a decision is made regarding cuff reuse.


Rationale

Results of hospital-based inspections and testing of reusable (not disposable) tourniquet cuffs, identifying patient hazards and risks, have been published in the AORN Journal and elsewhere, eg [2-9].

Reusable tourniquet cuffs that are specifically intended by their manufacturers to be used in multiple surgeries generally are accompanied by some instructions on how to inspect, clean and test such cuffs between uses. Often, the instructions are limited and no information is provided on cuff testing programs, on cuff testing protocols and on the documentation and evaluation of cuff testing results.

Disposable tourniquet cuffs are generally supplied as sterile, single-use products by manufacturers. Some facilities and individuals reuse disposable cuffs. However, there are no established guidelines at present to assure patient safety during reuse.

Hazards and risks are associated with unauthorized reprocessing and inadequate testing of reprocessed disposable cuffs. [11] Reprocessing efforts typically involve saving rather than discarding a disposable tourniquet cuff after surgery, visually examining the cuff to identify any obvious deterioration that might suggest reprocessing is not appropriate, attempting to remove any blood and other surgical debris by washing the cuffs with water combined with any of a variety of detergents or other cleaning liquids, disinfecting in some instances with various disinfecting agents, and in some cases conducting functional tests of the cuff, often using non-standard protocols and results that are neither documented nor evaluated relative to established criteria.

Some of these disposable cuffs may be reused as non-sterile cuffs after only cleaning, or after only cleaning and disinfection, with no functional testing and with no attempt to re-sterilize the cuff. In other situations, cleaned cuffs may be re-packaged and then re-sterilized by exposure to a sterilization agent within a sterilization process that may be different from that determined by the original manufacturer to be safe and effective. Reprocessing of disposable tourniquet cuffs, with or without re-sterilization, may be carried out within hospitals or surgery centers or by third-party reprocessors, and the quality and methods of reprocessing are highly variable.

Reprocessing of disposable tourniquet cuffs may result in hazards for the surgical patients on whom such cuffs are subsequently used. One such hazard arises from deterioration of cuff materials due to the use of any of a variety of chemical or physical agents that are attendant with the reprocessing, cleaning, disinfection and possible re-sterilizing processes. For example, exposure of a cuff to liquids during cleaning and disinfection may allow the liquids to enter and partially or completely block the pneumatic passageway within the port and inflatable portion of the cuff. If the cuff is re-sterilized as part of the reprocessing, any water remaining within the pneumatic passageway after cleaning may subsequently react chemically with ethylene oxide, a sterilizing agent commonly used in reprocessing, to form ethylene glycol, a sticky substance that may completely or partially block the pneumatic passageway.

Repeated exposure of cuffs containing flexible thermoplastic materials to an elevated temperature during drying after cleaning or disinfection with liquids, or during re-sterilization, may soften thermoplastic materials and components, increasing the likelihood of hazardous deformation of some components, including: substantial deformation of the thermoplastic stiffener included in some cuffs that may impair the application of pressure by such a cuff to an underlying limb upon subsequent use in surgery; partial or complete blockages of the pneumatic passageways within ports or thermoplastic connectors of some cuffs; and weakening of the retention force of typical thermoplastic barb-type port connectors so that such connectors cannot establish or reliably maintain a gas-tight passageway between the tourniquet cuff and tourniquet instrument upon reuse. In general, repeated reuse of a disposable tourniquet cuff beyond the limit of usage specified by the manufacturer, including exposure to cleaning and disinfection agents and processes not anticipated by the manufacturer if reused as non-sterile cuffs, and including exposure to re-sterilization agents and processes if reused as sterile cuffs, may progressively increase the hazards for the surgical patients on whom the cuff is used.


References and Citations

1. http://www.aorn.org/PracticeResources/AORNStandardsAndRecommendedPractices/EDocuments/ AORN, Recommended Practices for the Use of the Pneumatic Tourniquet, 2009.

2. www.tourniquets.org – McEwen JA, Educational website focused on surgical tourniquets, and related tourniquets for military and emergency applications, including tourniquet safety and usage.

3. McEwen JA, Auchinleck GF. “Advances in surgical tourniquets.” AORN Journal, 36(5) (1982): 889-96.

4. McEwen JA, Kelly DL, Jardanowski T, Inkpen K. “Tourniquet safety in lower leg applications.” Orthopaedic Nursing, 21(5) (2002): 55-62.

5. McEwen JA, Inkpen K. “Tourniquet safety: Preventing skin injuries.” The Surgical Technologist, 24(8) (2002): 6-15.

6. McEwen JA, Inkpen K, Younger A.”Thigh tourniquet safety.” The Surgical Technologist, 24(7) (2002): 9-18.

7. Tredwell SJ, Wilmink M, Inkpen K, McEwen JA. “Pediatric tourniquets: Analysis of cuff/limb interface and guidelines for use.” Journal of Pediatric Orthopaedics, 21(5) (2001): 671-6.

8. McEwen JA. “Complications of and improvements in pneumatic tourniquets used in surgery.” Medical Instrumentation, 15(4) (1981): 253-7.

9. Noordin et al. “Surgical Tourniquets in Orthopaedics” Journal of Bone and Joint Surgery, 91 (2009): 2958-2967. http://www.jbjs.org/

10. McEwen JA et al, “Integrated tourniquet system.” US Pat. App. No. 20100211096, Aug 2010. http://patft.uspto.gov/

11. McEwen JA and Jameson M. “Surgical tourniquet cuff for limiting usage to improve safety.” US Pat No. 7,955,352, June 2011. http://patft.uspto.gov/


 

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Tourniquet Safety and Intravenous Regional Anesthesia (IVRA, also called Bier Block Anesthesia): What’s New and Why?

Posted on June 21, 2011. Filed under: Bier Block Anesthesia, IVRA, Tourniquet Safety |

Many tourniquet systems are used for intravenous regional anesthesia (IVRA), also known as Bier block anesthesia.   IVRA is a tourniquet-related alternative to general anesthesia for limb surgery that is inexpensive and widely used with adult and pediatric patients, with the frequency varying by type of surgery and patterns of practice [1].

In IVRA, blood is first exsanguinated from the limb, usually by wrapping it with an elastic bandage, beginning distally and squeezing and wrapping toward the heart.  A dual-bladder tourniquet cuff is then applied proximal to the operative site and pressurized.  The elastic bandage is removed and a local anesthetic agent is injected into the limb through an intravenous cannula.  The local anesthetic remains in the limb as long as the tourniquet is inflated.  About 20 minutes after infusion, most of the anesthetic agent has been absorbed into the limb tissues and deflation of the tourniquet will not result in systemic release of the agent in high concentration.  IVRA may be performed by anaesthesiologists, anesthetists, nurse-anesthetists, surgeons, or occasionally others.

Surgical tourniquet systems, including tourniquet cuffs and instruments, play a vital role in the safety and success of IVRA.  [2]   Safe and successful IVRA typically requires the use of tourniquet instruments and cuff having advanced capabilities, including: two independent pneumatic channels, additional IVRA hazard suppression features, and special-purpose dual-bladder tourniquet cuffs (although special single-channel cuffs may occasionally be used).  [3-4]   Thorough testing of tourniquet instruments and cuffs prior to use, with results documented and checked, is also necessary to prevent hazards. [5-6]

IVRA has proven to be very simple, safe and effective over many years and large numbers of patients, when performed properly according to established protocols with safe, accurate and reliable tourniquet instruments and cuffs that have been thoroughly tested prior to use.  [3-6] However, IVRA is not without risk.  [1-2]  Risks may be associated with inherent safety limitations of tourniquet instruments and tourniquet cuffs not specifically designed for IVRA, with failures of tourniquet instruments and cuffs during use, and with incomplete testing of instruments and cuffs prior to use.  Those risks increase with non-standard protocols and with staff having limited training and experience with IVRA. [1]   Some reports of IVRA-related injuries, hazards and their causes are given in the reference and citations below [1-7].

In the past, injuries associated with IVRA have been reported, eg [1].  The deaths involved a combination of an agent no longer recommended for IVRA, failure of tourniquet instruments and cuffs and human error.    Hazards associated with IVRA can include failure to establish limb anesthesia, complete or partial loss of limb anesthesia, the sudden release of a bolus of anesthetic agent into systemic circulation, venous congestion and the loss of a clear surgical field.

Safe IVRA requires the use of advanced tourniquet systems, including both tourniquet cuffs and instruments, which are reliable, accurate, safe and effective [3, 4, 6].  Some notable and unique improvements which have added considerable value and safety to modern tourniquet instruments and cuffs for IVRA include:

Tourniquet instruments having two completely independent channels for independent, accurate and reliable control of the tourniquet pressure in each bladder of a tourniquet cuff used for IVRA.  This is especially important when individual bladders are being selectively depressurized, pressurized and regulated during IVRA.

Variable-contour dual-bladder tourniquet cuffs, in which the cuff shape matches patient-specific limb shapes from proximal edge to distal edge beneath each of the dual bladders, improving the uniform and reliable application of tourniquet pressure from each bladder to the underlying limb.  Such cuffs include additional features to improve safety in IVRA, such as dual independent fasteners to help prevent sudden cuff detachment and release, positive locking connectors and improved gas passageways within the cuffs.

Automatic measurement of Limb Occlusion Pressure (LOP) embedded in some tourniquet instruments, so that patient-specific tourniquet pressures can be accurately determined or checked (for each bladder of a dual-bladder cuff), for each surgical procedure, limb location, limb shape, and technique of cuff application.

IVRA safety lockout embedded in some tourniquet instruments, to help prevent staff from inadvertently and unintentionally deflating both bladders of a dual-bladder cuff during a procedure, thereby helping prevent the hazard of a sudden and unanticipated loss of IVRA.

Automatic cuff testing capability embedded in some tourniquet instruments, to allow staff to quickly, automatically and thoroughly test tourniquet cuffs, according to recommended practices, prior to use in IVRA and especially after any cleaning or reprocessing. [8]

Automatic cuff leak detection embedded in some tourniquet instruments, to detect leaking cuffs, connectors and tubing during use and to identify them to users after each procedure, thereby helping to prevent their hazardous use in subsequent IVRA procedures.

 

Further Reading

Advanced safety lockout mechanisms for IVRA tourniquets.

References and Citations

[1]  Henderson CL, Warriner CB, McEwen JA, Merrick PM. “A North American survey of intravenous regional anesthesia.” Anesthesia and Analgesia, 85 (1997): 858-63.

[2]  ECRI, Pneumatic Tourniquets Used for Regional Anesthesia: Hazard. Health Devices Dec 1982;12(2):48-9  www.mdsr.ecri.org/summary/detail.aspx?doc_id=8080

[3]  Noordin et al. “Surgical Tourniquets in Orthopaedics” Journal of Bone and Joint Surgery, 91 (2009): 2958-2967.

[4]  www.tourniquets.org – McEwen JA, Educational website focused on surgical tourniquets, and related tourniquets for military and emergency applications, including tourniquet safety and usage.

[5]  McEwen JA, Auchinleck GF. “Advances in surgical tourniquets.” AORN Journal, 36(5) (1982): 889-96.

[6]  McEwen JA. “Complications of and improvements in pneumatic tourniquets used in surgery.” Medical Instrumentation, 15(4) (1981): 253-7.

[7]  http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/search.cfm – MAUDE – Manufacturer and User Facility Device Experience, US Food and Drug Administration

[8]  http://www.aorn.org/PracticeResources/AORNStandardsAndRecommendedPractices/EDocuments/  AORN, Recommended Practices for the Use of the Pneumatic Tourniquet, 2009.

 

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