Over a two-year period, 265 Norwegian orthopaedic surgeons working at 71 institutions performed 63 484 operations under a tourniquet. Their replies to a questionnaire revealed that they mostly followed modern guidelines in their use of the tourniquet. Most felt that the tourniquet could be left on for two hours, and that it could be re-applied after 15 minutes. A total of 26 complications (one in 2442 operations) that might have been due to the tourniquet were reported, of which 15 were neurological. Three were in the upper limb (one in 6155 operations) and 12 in the lower limb (one in 3752 operations). Two were permanent (one in 31742 operations), but the remainder resolved within six months. One permanent and one transient complication occurred after tourniquet times of three hours. The incidence of tourniquet complications is still at least as high as that estimated in the 1970s.
The pneumatic tourniquet was introduced by Harvey Cushing in 1904 and is widely used in orthopaedic surgery to create a bloodless field in limb surgery. It allows meticulous surgical dissection and causes less morbidity than when an Esmarch bandage is used as a tourniquet.1 Nonetheless, complications still occur, of which nerve damage causing paralysis is the most feared.
Middleton and Varian2 reported that the incidence of tourniquet complications in Australia in the 1970s was approximately one in 5000 applications on the upper limb and one in 13 000 on the lower limb. Since then the design of the pneumatic tourniquet has been improved. It has been made wider, and the most recent models are conical to give a better fit. These changes reduce the pressure needed to stop arterial flow, thereby minimising the pressure on the compromised peripheral nerves, given that pressure and the duration of nerve ischaemia are the two main factors causing nerve injury.3–5
The purpose of this study was to survey how the tourniquet is used in clinical practice in Norway and to estimate the incidence and nature of complications of its use.
A questionnaire was sent to all members of the Norwegian Orthopaedic Society enquiring about their use of the tourniquet. Specific questions were asked about the type of tourniquet, pressure, location, and time limits. Respondents were asked whether they released the tourniquet temporarily during long operations, how long they felt the interval should be, and for how long they could keep it inflated afterwards. They were also asked to report any complications at their hospital due to tourniquet use during the previous two years (1998 and 1999). If a complication had been reported, the hospital was contacted again two years later and details were obtained about the operation and its outcome.
In order to establish the incidence of complications, we obtained from the Norwegian patient register the total number of operations that had probably been performed in a bloodless field during the same two-year period. We only included hospitals from which a surgeon had replied to the questionnaire.
A total of 265 of 398 (67%) orthopaedic surgeons from 71 hospitals replied to the questionnaire. The estimated number of operations carried out using a tourniquet at these hospitals during this two-year period was 63 484.
Many surgeons reported that they varied in their individual practice, using either a fixed tourniquet pressure or a pressure related to the patient’s systolic blood pressure. The most common method was to apply a pressure of 100 mmHg above the systolic blood pressure (Table I⇓). If a fixed pressure was used, it was usually 250 mmHg on the upper arm and 300 mmHg on the thigh (Table II⇓).
There were 108 surgeons who stated that one should use a lower tourniquet pressure for children, and 40 felt that the pressure could be reduced with a wider cuff. Five surgeons reported that they took account of the circumference of the extremity when deciding on tourniquet pressure, and one used a lower tourniquet pressure with general anaesthesia than with a local anaesthetic.
Most respondents felt that they could operate safely for two hours with the tourniquet inflated (Table III⇓). When asked if they released the tourniquet for a while if the operation lasted longer than two hours, 80% answered yes, 13% no, and 7% that their operations never exceeded two hours. The median deflation time was 15 minutes and median permitted operation time after re-inflation was 60 minutes.
A pneumatic tourniquet was used by 72%, 14% used the Esmarch bandage as a tourniquet, and the remaining 14% did not reply to this question. The tourniquet was most frequently placed on the upper arm or the thigh, whether fixed or systolic-related tourniquet pressures were used (Table IV⇓).
Over the two-year period 26 complications were reported to have occurred. Six were compartment syndrome or deep-vein thrombosis, which were thought more likely to be a complication of the injury or the operation than due to the use of a tourniquet. It was not possible to obtain further information on two complications, as neither the surgeon who had reported them nor anyone else on the medical staff could remember them. They were therefore excluded from the study. The remaining 18 complications consisted of three cases of blistering and skin necrosis, and 15 nerve complications, only two of which were permanent. Both were a paresis, one of the extensors of the wrist and hand, leading to a wrist drop, and the other of the peroneal nerve causing a foot drop. The remaining 13 nerve complications resolved spontaneously within six months of surgery. These included one patient with a complete sensory and motor palsy in the arm, six patients with a paresis and six with sensory disturbance. Most of the complications occurred after the tourniquet had been inflated for less than two hours at a pressure of 300 mmHg or less. The permanent wrist drop, however, occurred after a tourniquet time of 130 minutes and a pressure of 300 mmHg in an otherwise healthy 55-year-old man. The patient with a temporary but complete sensory and motor palsy in the arm had a tourniquet time of 180 minutes at a pressure of 250 mmHg.
Only three of the nerve complications (one in 6155 operations) were in the arm, the other 12 (one in 3752 operations) were in the lower limb. The overall incidence of neurological complications was 0.024% (one in 4232 operations; 15 in 63 484) and of permanent injury 0.032% (one in 31 742; 2 in 63 484). If the skin complications are included, the overall incidence of tourniquet complications was 0.028% (one in 3526), and if the two possible complications where data were lacking are also included, the incidence was 0.032% (one in 3174).
Complications of tourniquet use are fortunately very rare, although this inevitably makes an exact estimate of their incidence difficult.
For this study, in order to estimate the total number of operations carried out, we had to make the assumption that all operations that are usually performed in a bloodless field required the use of a tourniquet.
Of all Norwegian orthopaedic surgeons, two-thirds took part in the study. Our findings, therefore, probably reflect the use of the tourniquet in Norway fairly accurately. It appears that most surgeons follow modern recommendations regarding cuff pressures and ischaemia time. The most frequent cause of blistering of the skin is seepage of antiseptic solution into the padding beneath the cuff during skin preparation, resulting in a chemical burn. This is easily prevented by wrapping a plastic drape around the distal edge of the cuff. A median time of 15 minutes’ reperfusion in our study is somewhat short. The recommended time according to Wilgis6 is 15 to 20 minutes after two hours’ inflation.
The maximum permitted tourniquet time has been the subject of much debate. Klenerman7 concluded that three hours’ ischaemia is well within the timescale likely to produce irreversible muscle damage. Korthals, Maki and Gieron8 showed that nerves in ischaemic limbs in cats undergo mild necrotic changes after five hours, and moderate to severe changes after eight hours. Paletta, Willman and Ship9 showed that the tourniquet time could be prolonged considerably by cooling the limb and by giving heparin pre-operatively or just before releasing the tourniquet.
Klenerman7 has pointed out that the usual cause of nerve damage in clinical practice is an abnormally high cuff pressure. Neimkin and Smith10 developed a method using double tourniquet cuffs which they alternated at one-hour intervals, thereby preventing continued compression of a localised segment of the limb. This, however, does not reduce the total pressure on the arm, which can only be achieved by using a wider tourniquet.11
Our findings of a neurological complication for approximately every 6000 tourniquets on the upper limb and one for approximately every 3700 on the lower limb are similar to those of Middleton and Varian2 for the upper limb, but much higher than the one in 13 000 they estimated for the lower limb. The total incidence in our study was one in 4200, compared with one in 8000 in Middleton and Varian’s report.2 In spite of increased awareness of the potential for nerve damage when using the tourniquet, and modifications to the tourniquet which allow lower and more controlled pressures, there has been no reduction in the total incidence of neurological tourniquet complications. On the contrary, in our study the incidence seems to be higher. In Middleton and Varian’s study,2 about half the surgeons used an Esmarch bandage as a tourniquet on the lower limb. This can produce extremely high pressures, and a disproportionate number of their complications occurred after such use.2 We were, therefore, expecting a lower complication rate in our study, but in the event found it to be higher. A possible explanation for this is that in our estimate of the number of operations performed we may be closer to the true number than were Middleton and Varian,2 who simply estimated that each surgeon had performed 200 operations.
A few Norwegian surgeons still use the Esmarch bandage as a tourniquet. However, none of the complications occured among these patients. Two of the major complications occurred with tourniquet times of 130 and 180 minutes and with acceptable pressures of 250 and 300 mmHg, suggesting that the ischaemia time is an important factor.
Bushell et al12,13 found that, in rats, a preliminary period of ischaemia of five minutes, followed by reperfusion for five minutes before the main period of ischaemia, seemed to have a protective effect on the skeletal musculature. This may have an application in clinical practice.
Much effort has gone into reducing the required tourniquet pressure by changing the cuff size and design.4,10,11,14,15 Until further design improvements are made, possibly in the form of double tourniquets with alternating inflation, or cuffs incorporating a cooling system, it would seem appropriate to observe the common recommendation of a maximum of two hours’ ischaemia time in order to reduce the occurrence of permanent nerve damage.
A further opinion by Professor Leslie Klenerman is available with the electronic version of this paper on our website at www.jbjs.org.uk
No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article.
- Received January 18, 2006.
- Accepted April 11, 2006.
- © 2006 British Editorial Society of Bone and Joint Surgery