Intravenous Regional Anesthesia (IVRA)

What is Intravenous Regional Anesthesia?

Intravenous regional anesthesia is a tourniquet-related alternative to general anesthesia for limb surgeries. It is inexpensive and widely used for both adults and pediatric patients, with the frequency varying by the type of surgery and practice patterns [1].

In IVRA, a dual-bladder cuff or two single-bladder cuffs are applied proximal to the operative site. Blood is subsequently exsanguinated from the limb by elevation or by using an elastic bandage wrapped around the limb, beginning distally and squeezing and wrapping toward the heart. The cuff is then pressurized, and the elastic bandage is removed. 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. Approximately 20 minutes after infusion, most of the anesthetic agent has been absorbed into the limb tissues and the deflation of the tourniquet cuff will not result in the systemic release of the agent in high concentration. Dual-bladder cuffs and two single-bladder cuffs allow the anesthesia professional to control the inflation and deflation of each bladder separately, thereby increasing patient safety and comfort during surgery.

IVRA has proven to be very simple, safe, and effective over many years in a large number 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 [2-4]. However, IVRA is not without risk. These risks may be associated with the inherent safety limitations of tourniquet instruments and cuffs that are 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 who have limited training and experience with IVRA.

The following should be considered when performing an IVRA procedure:

Tourniquet users must be familiar with safe inflation-deflation sequence when using a dual-bladder cuff or when using two single-bladder cuffs together for IVRA. If the wrong bladder or cuff is released inadvertently due to user error, a significant hazard to the patient could result [5]. In addition, the user must be familiar with operation of the tourniquet instrument and any auxiliary pneumatic valves connected to the cuffs. The safest tourniquet systems incorporate IVRA interlocks and other safety features to help reduce the risk of accidental deflation during an IVRA procedure. To further reduce risks, users must be fully aware of which bladder or cuff is proximal, which bladder or cuff is distal, and the inflation/deflation status of each at all times.

The tourniquet procedure for IVRA is similar to other tourniquet procedures, with the following important differences:

  1. When conducting a preoperative assessment prior to IVRA, it is very important to note any allergies to local anesthetics.
  2. A dual-bladder tourniquet cuff is required.
  3. A wider placement site is needed because of the dual-bladder cuff.
  4. A higher pressure is generally required because each cuff bladder is narrower, and the optimal pressure should be based on Limb Occlusion Pressure (LOP) measurement. Click here to learn more about LOP.

Tourniquet application for IVRA

  1. The patient will be awake for the procedure.  To alleviate any fears related to the procedure, explain the equipment, alarms, or other unfamiliar items.
  2. Cannulate a vein in the distal portion of the limb. (An angiocath is preferred to a butterfly needle because it is less likely to be moved out of position during application of the elastic bandage.)
  3. Apply limb protection (if used) to the limb. If available, select a limb protection sleeve matched to the tourniquet cuff 6-7]. Click here to learn more about matching limb protection sleeves.
  4. Apply the dual-bladder tourniquet smoothly and snugly, individually fitting each bladder to the shape and circumference of the patient’s limb.
  5. Connect each bladder of the dual-bladder cuff to the tourniquet instrument. (Consult the tourniquet instrument instruction manual for more information on this connection. If a dual-cuff control valve is used between the tourniquet instrument and the cuff, ensure that you are familiar with the connection and safe operation of the valve.
  6. Fold the distal portion of the limb protection sleeve back over the distal edge of the cuff. Place the protective plastic drape around the tourniquet and limb.
  7. Elevate the limb and wrap with the elastic bandage to exsanguinate the limb.
  8. Inflate the proximal bladder to the desired pressure. (Generally, the proximal bladder is inflated first, but sometimes the distal bladder is the first one inflated in order to complete exsanguination). Limb Occlusion Pressure (LOP) is particularly useful in setting the cuff pressure in IVRA procedures due to the importance of maintaining occlusion and the generally higher pressures required due to the narrow width of each bladder.
  9. Remove the elastic bandage.
  10. Verify full occlusion by palpation and/or auscultation.

Induction of anesthesia

After tourniquet placement, the following steps may be taken to induce IVRA. This procedure is presented as a general guideline and may differ in your institution:

  1. A predetermined amount of local anesthetic is slowly injected into the cannulated vein via syringe or drip method (usually the responsibility of the anesthesia professional). Care must be exercised not to over distend the vein by rapid infusion.
  2. Immediately begin to observe the patient’s physiological status for any sign or symptom of a toxic reaction to the local anesthetic. (The presence of an anesthesia professional in this instance does not release the nurse from noting any adverse or toxic reactions to the anesthetic agent.)
  3. The anesthetic agent circulates throughout the veins and venules distal to the tourniquet and perfuses the sensory and motor nerve trunks and endings.
  4. In about 3 minutes, the limb should be anesthetized. During this time the limb may be prepped and draped for the surgical procedure.
  5. About 20-30 minutes following the onset of anesthesia, if the patient feels pain from the cuff, inflate the distal tourniquet over the anesthetized limb and deflate the proximal tourniquet. The patient should feel more comfortable since the tissue under the distal bladder has been anesthetized. NOTE: Tourniquet users must be familiar with the safe inflation-deflation sequence described below when using a dual-bladder cuff.

Deflating the tourniquet

NOTE: Tourniquet users must be familiar with the safe inflation-deflation sequence when using a dual-bladder cuff or using two single-bladder cuffs together. If the wrong bladder or cuff is released accidentally, it could be hazardous to the patient [5]. Never leave the patient unattended for any reason during intermittent deflation.

  1. When IVRA is used, it has been suggested in published literature that the tourniquet remain inflated for a minimum of 20 minutes from the time of injection to ensure that most of the anesthetic agent has been absorbed into the limb tissue. For a procedure requiring only a few minutes, too rapid a release of anesthetic agent can be prevented by quickly deflating and reinflating the cuff several times, or by slowly decreasing the cuff pressure.
  2. Upon completion of the procedure, fully deflate the tourniquet bladder, while the surgeon elevates the limb to enhance venous return and exerts pressure over the incision to prevent bleeding and hematoma formation. Deflation to zero pressure each time is important to prevent venous distention, which leads to bleeding and hematoma formation. A short (15 second) deflation period permits the wash of local anesthesia and anaerobic waste products back into the general circulation in small doses to minimize toxic reactions.
  3. Observe the patient’s mental status and cardiac monitor carefully, as this is the time when complications are most likely to occur.
  4. Reinflate for 30-45 seconds to allow nourishment of the tissue with oxygenated blood and diffusion of the anesthetic agent and waste products back into venous circulation.
  5. Apply the dressing and move the patient to the recovery area.
  6. The anesthetic effect recedes within 15-20 minutes, and patients can be safely discharged from the post anesthesia care unit more promptly than when other anesthetic techniques are used.

Some notable and unique improvements that have added considerable value and safety to modern tourniquet instruments and cuffs for IVRA include:

  • Tourniquet instruments having two completely independent channels:
    • Two channels provide 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:
    • With these cuffs, the cuff shape matches patient-specific limb shapes from the proximal edge to the distal edge beneath each of the dual bladders, thereby improving the uniform and reliable application of tourniquet pressure from each bladder to the underlying limb. These cuffs also 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. Click here to find out more about tourniquet cuff technology.
  • IVRA safety lockout:
    • This capability is embedded in some modern tourniquet instruments to help prevent the surgical staff from inadvertently or 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 [8].
  • Automatic cuff testing capability:
    • Also embedded in some modern tourniquet instruments, this capability allows the perioperative nurse to quickly, automatically, and thoroughly test tourniquet cuffs, according to recommended practices, prior to use in IVRA and, in particular, after cleaning and reprocessing [9].
  • Automatic cuff leak detection:
    • This capability, embedded in some tourniquet instruments, detects leaking cuffs, connectors, and tubing during use and alerts the staff after each procedure, thus helping prevent their hazardous use in subsequent IVRA procedures [10].
  • Automatic measurement of LOP:
    • This capability is embedded in some tourniquet instruments so that patient-specific tourniquet pressures can be accurately determined (for each bladder of a dual-bladder cuff) for each procedure, limb location, limb shape, and technique of cuff application.
    • In literature, 250 mmHg or 100 mmHg above the patient’s systolic pressure are commonly cited as the most often used pressures for upper-extremity IVRA, despite little scientific evidence to support this [1].
    • Limb occlusion pressure has been recommended as the most appropriate method for determining the optimal tourniquet pressure, making evaluation of LOP for every patient an important prerequisite to choosing the tourniquet inflation pressure [2]. Click here to learn more about Limb Occlusion Pressure.

Sources

[1] Henderson CL, Warriner CB, McEwen JA, Merrick PM. A North American survey of intravenous regional anesthesia. Anesthesia & Analgesia. 1997 Oct 1;85(4):858-63.

[2] Noordin S, McEwen JA, Kragh Jr CJ, Eisen A, Masri BA. Surgical tourniquets in orthopaedics. JBJS. 2009 Dec 1;91(12):2958-67.

[3] McEwen JA, Auchinleck GF. Advances in surgical tourniquets. AORN journal. 1982 Nov 1;36(5):889-96.

[4] McEwen JA. Complications of and improvements in pneumatic tourniquets used in surgery. Med Instrum. 1981 Jul;15(4):253-7.

[5] AORN. Recommended practices for care of patients undergoing pneumatic tourniquet-assisted procedures. In: Perioperative Standards and Recommended Practices. AORN, Inc.; 2015.

[6] Tredwell SJ, Wilmink M, Inkpen K, McEwen JA. Pediatric tourniquets: analysis of cuff and limb interface, current practice, and guidelines for use. Journal of Pediatric Orthopaedics. 2001 Sep 1;21(5):671-6.

[7] Olivecrona C, Tidermark J, Hamberg P, Ponzer S, Cederfjäll C. Skin protection underneath the pneumatic tourniquet during total knee arthroplasty: a randomized controlled trial of 92 patients. Acta orthopaedica. 2006 Jan 1;77(3):519-23.

[8] McEwen JA, Jameson M, inventors; Mcewen, James A., Jameson, Michael, assignee. Physiologic tourniquet for intravenous regional anesthesia. United States patent US 5,556,415. 1996 Sep 17.

[9] McEwen JA, inventor; Western Clinical Engineering Ltd., assignee. Adaptive pneumatic tourniquet. United States patent US 4,479,494. 1984 Oct 30.

[10] McEwen JA, Jameson M, Gebert MA, Cheung WK, inventors; Western Clinical Engineering Ltd., assignee. Apparatus and method for estimating leakage in a surgical tourniquet system. United States patent US 8,083,763. 2011 Dec 27.