Safety Considerations During Use
The following should be considered during tourniquet use to reduce the risk of tourniquet-related complications:
- Intraoperative monitoring
- Tourniquet deflation
- Bilateral procedures
- Intravenous Regional Anesthesia procedures
Intraoperative monitoring of tourniquet safety parameters reduces the risk of complications. During the procedure, it is important to monitor the patient’s blood pressure, tourniquet pressure, and tourniquet time.
Monitor the patient’s blood pressure for fluctuations and relate this information to the surgeon.
Adjust the tourniquet pressure at the physician’s request. Many studies published in the medical literature have shown that higher tourniquet pressures and pressure gradients are associated with higher risks of tourniquet-related injuries [1-7]. Studies have also shown that lower tourniquet pressures are associated with lower complications and pain [8, 9]. Therefore, the best practice for setting tourniquet pressure is to set a personalized pressure that is based on Limb Occlusion Pressure (LOP). Click here to learn more about Limb Occlusion Pressure.
Monitor the cuff pressure display during surgery and immediately report any changes to the surgeon. Any sudden loss of cuff pressure intraoperatively is a cause for serious concern. If the tourniquet cuff fails for any reason, deflate it fully, and re-exsanguinate the limb before re-inflation. Re-inflation over blood-filled vasculature may lead to intravascular thrombosis.
Tourniquet inflation time has a direct correlation to tourniquet-related complications (ie, increased inflation time increases the risk for injury) . There is no clearcut rule as to how long a tourniquet may be inflated safely, although various investigators have addressed effects of ischemia on muscle and nerve to define a relatively “safe” period of tourniquet hemostasis. In practice, safe tourniquet inflation time depends greatly on the patient’s anatomy, age, physical status, and the vascular supply to the extremity. Unless instructed otherwise, report to the surgeon when 60 minutes of tourniquet time has elapsed. There is general agreement that for reasonably healthy adults, 90 minutes should not be exceeded without releasing the tourniquet for a short time. However, it should be remembered that longer tourniquet times are associated with higher probability of injury.
It is the physician’s responsibility to determine when the tourniquet is to be inflated, at what pressure, for how long, and at what point in the procedure the tourniquet should be released. It is customary to prominently note the time of cuff inflation and to notify the physician after a certain time has elapsed and at pre-established intervals thereafter. Modern electronic tourniquet systems have an elapsed time display and an alarm which can be set to sound after a predetermined amount of tourniquet inflation time.
Releasing the tourniquet allows for removal of metabolic waste products from the limb and nourishment of the tissue with oxygenated blood. During this time, elevate the limb 60 degrees to encourage venous return and apply steady pressure to the incision with a sterile dressing. Tissue aeration periods should last at least 10 and preferably 15 minutes the first time and 15-20 minutes subsequently. To proceed with the surgery, re-exsanguinate the limb before reinflating the cuff. Take care during this procedure to maintain the sterility of the operative field. No known safe limit to the number of aeration intervals during prolonged tourniquet time has been established.
At the surgeon’s request, deflate the tourniquet cuff by taking the following steps:
- Apply pressure dressings over the incision to protect the wound from blood resurgence. Ideally, the final bandage is applied and pressure is exerted over the incision prior to tourniquet cuff deflation, to prevent blood resurgence. Sometimes, however, the tourniquet is deflated before incisional closure in order to better identify and control bleeding.
- If necessary to prevent blood resurgence, elevate the limb 45-60 degrees. Transient pain upon tourniquet release can also be lessened by elevating the limb.
- Deflate the tourniquet cuff rapidly to establish immediate venous return and prevent engorgement.
- Record the time of deflation.
- Immediately remove the deflated cuff and any underlying limb protection following cuff deflation. Even the slightest impedance of venous return by the deflated cuff or padding may lead to congestion and pooling of blood in the operative field.
- Record the time of cuff removal.
- Check the circulation of the limb. Note the return of color to the limb and any abnormalities. If full color does not return within 3-4 minutes after release, place the limb slightly below body level.
- Inspect the cuff site and note any signs of soft tissue damage.
Additional care must be taken in bilateral procedures involving tourniquet control on two limbs, as the risk of complications and the effects of tourniquet use may be increased. Exsanguinating and inflating the cuff on both limbs in rapid succession may cause a more pronounced blood pressure rise due to the sudden decrease in effective circulation system volume. In studies, clotting time decreases and more pronounced blood pressure decreases were found after second cuff deflation. In children, body temperature rise during surgery has been shown to be significantly greater with bilateral tourniquets compared to unilateral, and more pronounced pH drops (greater lactate increases) were found when bilateral cuffs were deflated simultaneously. If possible, bilateral tourniquet deflations should be staggered by 30 to 45 minutes.
It is particularly important in the bilateral case to confirm that the first tourniquet cuff has been completely deflated (and the cuff and limb protection removed if possible) and that circulation in the first limb has been restored, because any related problems could go unnoticed throughout the second limb procedure.
Intravenous Regional Anesthesia Procedures
Tourniquet users must be familiar with the 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, it could cause severe injury to the patient. In addition, the users must be familiar with operation of the tourniquet instrument and any auxiliary pneumatic valves connected to the cuffs. Some more sophisticated tourniquet systems incorporate safety functions to help reduce the risk of accidental deflation of both cuffs during an IVRA procedure. To further reduce risks, users must be fully aware of which cuff is proximal, which cuff is distal, and the inflation/deflation status of each at all times. Click here to learn more about IVRA and its procedural differences with other tourniquet procedures.
Documentation of tourniquet use is always a nursing responsibility. Documentation provides information for continuity of care, retrospective review, and research. Careful records become particularly important if a patient sustains an injury and a lawsuit is filed. Record only observable facts, rather than any judgmental opinion.
Information is usually entered on a special record. Such records include, at minimum, the following items:
- Identification/serial number and model of the tourniquet
- Identification of the person who applied the cuff
- Location of the cuff
- Times of inflation and deflation of the tourniquet
- Length of tissue aeration periods, if applicable
- Original tourniquet pressure
- Initial systolic blood pressure
- Subsequent systolic blood pressures
- The fact that the surgeon was informed of elapsed tourniquet time and any alterations in systolic blood pressure
- Skin and tissue integrity under the cuff before use of the pneumatic tourniquet and when the patient is sent to postanesthesia recovery
- Any abnormal or adverse occurrences.
If an abnormal event occurs, note the time any symptoms began and ended. Enter adverse reactions on the appropriate record, as dictated by institutional policy. If a malfunction in the pneumatic tourniquet causes serious injury, or contributes to the death of a patient or other individual, this information should be reported to the manufacturer and to the U.S. Food and Drug Administration, in accordance with the Safe Medical Devices Act of 1990.
Table 1 provides sample troubleshooting guidelines. Many of these problems are device-specific, and may not apply to your tourniquet system. This is particularly true for computerized, digital systems. Read the manufacturer’s operating manual carefully for troubleshooting guidelines specific to your system.
Table 1. Troubleshooting Guide
|Malfunctioning pressure regulator||None, especially for non-computerized units||Calibrate regularly by biomedical
|Malfunctioning pressure display||Fails to return to 0 on complete depressurization||Pull out of service and send for repair.|
|Malfunctioning pressure display||Error of 10% or more when checked with mercury manometer||Have serviced regularly by biomedical engineering.|
|Malfunctioning pressure display||Computerized system indicates a calibration error||Have serviced by biomedical engineering.|
|Bladder or connecting tubing leaks||Gradual deflation of bladder; feel or hear leak through or around cuff, computerized system indicates low pressure or leak alarm||Tighten all connectors; replace cuffs or tubing if necessary.|
|Kinking of tubing||Failure of bladder to inflate; excess venting of gas through pressure release valve, computerized system indicates occlusion alarm||Turn connecting device to unkink tubing.|
|Failure to operate||Loss of electrical power receptacle.||Make sure plug is securely in|
 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 Medical and Biological Engineering Society 2009. Calgary, Canada; 2009 May 20-22. p 1-4.
 Graham B, Breault MJ, McEwen JA, McGraw RW. Perineural pressures under the pneumatic tourniquet in the upper extremity. The Journal of Hand Surgery: British & European Volume. 1992 Jun 1;17(3):262-6.
 Olivecrona C, Ponzer S, Hamberg P, Blomfeldt R. Lower tourniquet cuff pressure reduces postoperative wound complications after total knee arthroplasty. J Bone Joint Surg Am. 2012 Dec 19;94(24):2216-21.
 Younger AS, McEwen JA, Inkpen K. Wide contoured thigh cuffs and automated limb occlusion measurement allow lower tourniquet pressures. Clinical orthopaedics and related research. 2004 Nov 1;428:286-93.