Lower tourniquet cuff pressure reduces postoperative wound complications after total knee arthroplasty
An interesting paper from the Södersjukhuset Karolinska Institutet, in Stockholm Sweden evaluating the benefit of measuring limb occlusion pressure before surgery was recently published in the December 2012 issue of the Journal of Bone and Joint Surgery .
This randomized controlled study of 164 patients demonstrated a significant reduction in tourniquet pressure and more individual cuff pressures among patients when LOP was measured using 140 mm wide contour cuffs. Although the study method demonstrated no difference in postoperative pain between the LOP and control groups, the authors note that patients with cuff pressures below 225 mmHg had fewer postoperative complications.
The full abstract of the publication in the Journal of Bone and Joint Surgery is given below. 
Background: Measurement of limb occlusion pressure before surgery might lead to the use of a lower tourniquet cuff pressure during surgery and thereby reduce the risk of postoperative pain and complications. The primary aim of this study was to investigate whether the limb-occlusion-pressure method reduces the tourniquet cuff pressure used during total knee arthroplasty and if this leads to less postoperative pain compared with that experienced by patients on whom this method is not used. The secondary aim was to investigate whether there were any differences regarding the quality of the bloodless field, range of motion, and postoperative wound complications.
Methods: One hundred and sixty-four patients scheduled to be treated with a total knee arthroplasty were randomized to a control group or to undergo the intervention under study (the limb-occlusion-pressure [LOP] group). In the control group, the tourniquet cuff pressure was based on the patient’s systolic blood pressure and a margin decided by the surgeon (the routine method). In the LOP group, the tourniquet cuff pressure was based on the measurement of the limb occlusion pressure. The primary outcome measure was postoperative pain, and the secondary outcome measures were the quality of the bloodless field, knee motion, and wound-related complications at discharge and two months after surgery.
Results: The tourniquet cuff pressure was significantly lower in the LOP group than in the control group (p < 0.001). We could not demonstrate any differences between the groups regarding postoperative pain or complications, although the number of postoperative complications was relatively high in both groups. However, at discharge forty of the forty-seven patients with a wound complication had had a cuff pressure above 225 mm Hg and at the two-month follow-up evaluation fourteen of the sixteen patients with a wound complication had had a cuff pressure above 225 mm Hg.
Conclusions: The limb-occlusion-pressure method reduces the cuff pressure without reducing the quality of the bloodless field, but there were no differences in outcomes between the groups. An important secondary finding was that patients with a cuff pressure of 225 mm Hg had no postoperative infections and a lower rate of wound complications.
Level of Evidence: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.
 Olivecrona C, Ponzer S, Hamberg P, Blomfeldt R (2012) Lower tourniquet cuff pressure reduces postoperative wound complications after total knee arthroplasty: a randomized controlled study of 164 patients. J Bone Joint Surg Am 94:2216–2221Read Full Post | Make a Comment ( None so far )
What evidence exists to show the extent to which the use of limb protection sleeves underlying tourniquet cuffs improves patient safety? It is known that high pressures, high pressure gradients and shear forces applied to skin and soft tissues underlying a tourniquet cuff can cause injuries to the skin and soft tissues including petechiae, blistering, bruising, and pinching. To reduce the nature and extent of such injuries, studies have been published to determine the relative effectiveness of underlying padding, underlying stockinette, and underlying limb protection sleeves that are matched to specific limb sizes and cuff sizes.
Olivecrona et al.  compared the use of elastic stockinette, cast padding, and no protective material underneath a pneumatic tourniquet in 92 patients who underwent a primary total knee arthroplasty and confirmed that an elastic stockinette provided the most effective skin protection during tourniquet use, of the three that were studied. McEwen et al.  compared five different tourniquet cuff sleeve and padding configurations in healthy adult volunteers, and Tredwell et al.  tested four different tourniquet cuff sleeve and padding configurations on healthy child volunteers. Both studies found that stretched sleeves made of two-layer tubular elastic material and matched to specific tourniquet cuff sizes, and thus to limb sizes, produced significantly fewer, less severe pinches and wrinkles in the skin surface than other types of underlying limb protection that were tested, including cast padding, single-layer stockinette, and stockinette not matched to the cuff and limb size.
These studies present evidence that limb protection sleeves improve safety by protecting the skin underlying tourniquet cuffs during tourniquet use, and further provide evidence that greatest safety is achieved through the use of matching limb protection sleeves consisting of two-layer tubular stockinette specifically matched to the limb size and cuff size. Detailed information about matching limb protection sleeve products is available elsewhere .
 S. J. Tredwell, M. Wilmink, K. Inkpen, and J. a McEwen, “Pediatric tourniquets: analysis of cuff and limb interface, current practice, and guidelines for use.,” Journal of Pediatric Orthopedics, vol. 21, no. 5, pp. 671–6, 2001.
 C. Olivecrona, J. Tidermark, P. Hamberg, S. Ponzer, and C. Cederfjäll, “Skin protection underneath the pneumatic tourniquet during total knee arthroplasty: a randomized controlled trial of 92 patients.,” Acta Orthopaedica, vol. 77, no. 3, pp. 519–23, Jun. 2006.Read Full Post | Make a Comment ( None so far )
This article discusses hazards and limitations associated with the use of a Hemaclear elastic ring as a tourniquet.
The Hemaclear elastic ring has been shown to apply high pressure levels and high pressure gradients to the underlying limb and soft tissues [1, 2]. Such high pressure levels and high pressure gradients produced by this elastic ring have resulted in reports of high levels of pain [3, 4, 5]. In addition to pain, evidence in the published literature has shown that higher pressure gradients and higher pressure levels in tourniquets are associated with higher probabilities of injuries to underlying nerves and soft tissues [2,6].
Elastic tourniquets were used as tourniquets in the nineteenth century. However, their use was abandoned early in the twentieth century because of many recurring reports of serious nerve and soft tissue injuries resulting from elastic tourniquets, including permanent limb paralysis. They were replaced by pneumatic tourniquet systems which safely and reliably stop arterial blood flow at much lower tourniquet pressures and lower tourniquet pressure gradients [2,6].
Related hazards and limitations associated with recent efforts to re-introduce a non-pneumatic elastic ring as a tourniquet include the following.
1. The Hemaclear elastic ring does not measure the actual tourniquet pressure applied to the limb, nor does it measure the pressure gradient applied to the patient’s limb.
2. Thus a Hemaclear ring cannot provide the user with an accurate indication of the actual tourniquet pressure and pressure gradient applied to the patient’s limb.
3. There is no documented evidence of the actual pressure levels and pressure gradients applied to limbs by each size of Hemaclear elastic rings.
4. It is not possible to control the pressure applied by the Hemaclear elastic ring to the patient’s limb during a surgical procedure.
5. The surgical user is left with no practical contingency plan in the event of arterial bleeding in the limb distal to the Hemaclear ring during surgery, other than finding and cutting off the ring, and then using a pneumatic tourniquet.
6. Use of a Hemaclear elastic ring is impractical if there is a need for reperfusion of the limb during a long procedure that is typical of revision surgery.
7. Although the Hemaclear elastic ring has had very limited usage in the US to date, problems and hazards associated with this limited usage have already been reported to the FDA. For example: Report of Severe Pain and Report of Skin Tearing.
References (VIEW DETAILS)
 McEwen JA, Casey V. “Measurement of hazardous pressure levels and gradients produced on human limbs by non-pneumatic tourniquets.” Proc 32nd Can Med Biol Eng Conf. 2009, pp 1-4.
 Noordin S, McEwen JA, Kragh JF Jr, Eisen A, Masri BA. “Current Concepts Review: Surgical Tourniquets in Orthopaedics.” J Bone Joint Surg Am. 2009; 91:2958-67.
 Smith OJ, Heasley R, Eastwood G, Royle SG. “Comparison of pain perceived when using pneumatic or silicone ring tourniquets for local anaesthetic procedures in the upper limb.” J Hand Surg Eur. 19 June 2012. DOI: 10.1177/1753193412449116
 Report to FDA MedWatch on the Hemaclear elastic ring tourniquet, 2009
 McEwen JA. “Complications of and improvements in pneumatic tourniquets used in surgery.” Medical Instrumentation. 1981;14(4):253-7.Read Full Post | Make a Comment ( None so far )