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The tourniquet. Instrument or weapon?
The Tourniquet: Instrument or W e a p o n ? - - R o y Sanders
THE TOURNIQUET. INSTRUMENT
OR WEAPON?
R O Y SANDERS, Northwood, Middlesex We owe the term tourniquet to " L e grand" Petit who in 1718 engineered a screw compression device and first used the word "tourniquet" to describe it. Perhaps it is as well that only the term has persisted in daily use by hand surgeons. The original Esmarch bandage was a rubber tube the thickness of a finger and was later modified by von Langenbeck to its present form (Thompson, 1942). Griffiths (1970) pointed out that it is popular because it is convenient and easy to apply. It is always effective, probably because the pressure is too high; and it does not fail during operation. It is more stable than other tourniquets when applied to a flabby conical limb, but there is no British Standard for such tourniquets. They are usually 9 ft. (2,743 mm.) long, 3 ins. (76 ram.) wide and 155 in. (1.016 ram.) thick. Neither is there a standard arm to which it may be applied, nor a standard surgeon to apply it. Griffiths found that four turns on a limb of 15 ins. (382 ram.) circumference exerted an average pressure of 280 ram. Hg. We shall see later whether this is adequate and safe. A tourniquet, to be safe, should exert uniform and controlled pressure over a wide area. Harvey Cushing (1904), realised this. Having seen several paralyses resulting from too prolonged and energetic use of the elastic tourniquet, he developed the pneumatic tourniquet. This tool, although sometimes inconvenient and unreliable, provides the safest form of surgical ischaemia if properly padded; inflated to a known pressure; and observed by an interested anaesthetist. THE SITE OF APPLICATION OF THE TOURNIQUET
The tourniquet is most safely applied to that part of the limb which is of maximum circumference, and well padded with periosseous muscle. This is the most proximal part of the limb. Whereas it would be best to limit the ischaemia to the operative field only, this is usually, and unfortunately, the most distal part of the limb. Safety overrules convenience. Tourniquets should never be applied distal to knee or elbow. A pressure of 700 ram. Hg. in the cuff around a rabbit's thigh exerts a pressure of only 110 ram. Hg. on the sciatic nerve (Lundborg, 1970). Even in the presence of high pressure in a small limb the nerve is well protected. The circumference of the distal part of the limb is too small, and the nerves too vulnerable to 1ocalised high pressures for a tourniquet to be applied there. The dark venous and capillary ooze which occurs too often at the critical operative moment is usually blamed on a snoozing, smoking or coffee drinking anaesthetist who is alleged to have allowed the cuff to deflate. Furlow (1971) offers another explanation. He applied a tourniquet to the most proximal part of the limb of anaesthetised dogs and carried out amputations at various levels. Amputation just below the tourniquet caused venous ooze from the bony medulla only. Amputation at the elbow caused ooze from the muscle only. If the humerus was stripped of muscle below the tourniquet blood dripped from the veins emerging through the cortex of the lower end of the humerus. Thus the ooze is due to blood entering the bony medulla through nutrient arteries in the most proximal part of the limb. It escapes beneath the occluding tourniquet through the veins of the medulla, and emerges distally through the cortex into the muscular veins, and thence to our operative field. This "Medullary Bypass" is the cause of a bloody operation in the presence of an " a d e q u a t e " tourniquet. The solution is either to apply an arterial tourniquet at the level of the elbow which is unsafe, or to apply an arterial tourniquet proximally, and a venous one above and below the elbow. Pressure over bony structures is avoided and haemostasis is complete. The H a n d - - V o l . 5
No. 2
1973
119
7"he Tourniquet: Instrument or Weapon?--Roy Sanders EXSANGUINATION
Whether the vessels are empty of blood during operation will depend upon the preferences of the surgeon, and upon the operation being performed. Exsanguination has not been shown in the short or long term to be deleterious to the tourniquet limb, nor advantageous either. Bradford (1969) has shown that with the application of bilateral exsanguinating tourniquets to the lower limbs 700-800 mls of blood will be added to the remaining circulation of an adult patient. The central venous pressure m a y rise to a m e a n value of 17.5 cm water and when applied to one lower limb only, central venous pressure m a y rise to a mean value of 9.7 cm for five minutes. There is then a slow fall to resting levels. Exsanguination of one upper limb causes a rise of central venous pressure to 6 cm water, and a fall below zero on release. Without exsanguination no change in central venous pressure occurs on application or release of the pneumatic tourniquet. Thus care needs to be taken in cases where congestive cardiac failure is imminent or present, lest by exsanguination of one or more limbs a rapid increase of central venous pressure precipitates or exacerbates cardiac failure. PRESSURE I N THE C U F F
It has been empirically stated (Campbell, 1956) that m a x i m u m safe pressure for upper limb tourniquets is 300 ram. Hg., and for the lower limb 500 ram. Hg. Would it not be more sensible to use the m i n i m u m e~ective pressure rather than the m a x i m u m safe pressure? Clearly tourniquet pressure needs to be greater than arterial pressure. The arterial pressure m a y rise during surgery. H i n m a n (1945) noted rises in arterial pressure above preoperative levels of up to 70 ram. Hg. Thus a vigilant anaesthetist could maintain such a m i n i m u m effective pressure using a m e r c u r y manometer. The use of aneroid gauges m a y lead to disaster and to avoid such a possibility a safety device, like a pressure cooker valve which exhausts at known pressure, m a y be used (Hamilton and Sokoll, 1967). M a n y causes of tourniquet paralysis appear in the literature, and the number of reported cases has decreased with increased use of the pneumatic tourniquet (Moldaver, 1954). All types of tourniquet have been blamed but in each case the pressure was too high, or applied for too long. F o r years the debate has gone on as to whether nerve palsies are due to localised pressure or distal isehaemia. Lundborg (1970) has shown that ischaemia alone, for as much as six hours did not result in injury to walls of endoneural vessels sufficient to give rise to an extravascular leakage of albumin. Eight to ten hours of ischaemia were necessary for this to occur. In the compressed nerve segment, a prominent leakage of albumin f r o m endoneural vessels occurred after four hours cuff compression. Recovery of nerve conduction after two hours of ischaemia was rapid, but one hour after a limb had been subjected to two hours of compression and isehaemia, there was only minimal return of nerve excitability. Thus, localised compression of the nerve segment is the principal pathogenic factor in the production of nerve lesions after the use of a tourniquet. It should be r e m e m b e r e d that localised high pressure of a nerve against a bony prominence is more likely to produce injury than if the nerve is protected by a large muscle mass. In respect of nerve lesions therefore, it is the effective pressure of the tourniquet which is so critical. The correct pressure is the minimal pressure required to produce a bloodless field, and should not need to exceed preoperative systolic pressure by much more than 70 ram. Hg. 120
The Hand--Vol. 5
No. 2
1973
The Tourniquet: Instrument or Weapon?--Roy Sanders C H A N G E S O C C U R R I N G D U R I N G THE P E R I O D OF I S C H A E M I A
There are no significant microscopic or haematological changes in the ischaemic limb in animals or man during tourniquet times of less than four hours. The skin temperature of arms subjected to tourniquet falls by 1.5°C during one hour of ischaemia, and then rises above preoperative levels by a similar or greater margin on release. A spotlight and theatre light, in my experience, does not prevent this fall. CONSEQUENCES OF THE R E L E A S E OF THE T O U R N I Q U E T
Increased B l e e d i n g : -
By using a tourniquet we achieve a bloodless field during surgery, but pay the price on release. The phenomenon of reactive hyperaemia is well known. It may be used to advantage, as in McGregor's "tourniquet test" as a method of estimation of skin viability in degloving injuries (McGregor, 1960). More often it proves troublesome in that bleeding from damaged tissues seems to be increased. Nakahara (1967) confirmed a significant increase in bleeding tendency in dogs after tourniquet release. They found that it was greatest immediately after release, but still three times normal ten minutes later. We need to wait longer with gentle pressure for spontaneous haemostasis therefore than with a similar situation in a non-ischaemic wound. Blood coagulation time is increased immediately after release, is maximum five minutes later and significantly raised for at least one hour after release (Nakahara, 1967), and so offsets in part the vasodilatation. Many authors recommend the release of a tourniquet at hourly intervals, or less. On release of a tourniquet there is an initial phase when the blood flow is less than resting levels, probably due to a reflex vasoconstriction (Freeberg and Hyman, 1960) and the period of reduced flow tends to be proportional to the duration of ischaemia. If the tourniquet is to be reinflated after two hours ischaemia, it seems likely that at least ten minutes should be allowed before reinflation, for return of normal circulation (Walker, Paletta and Cooper, 1960). Swelling:-
The puffy, stiff hand is sometimes seen after operation under tourniquet. It is worthwhile to establish whether the tourniquet contributes to this oedema. Most of the experimental work into the cause and extent of tourniquet 0edema has been carried out on animals, with limb tourniquets applied for long periods. In the absence of added accidental or surgical trauma the swelling occurs within ten minutes of the release of the tourniquet (Paletta, 1960), and contains up to five per cent of proteins (Pochin, 1942). It is usually maximal at two hours and disappears after about one week (Lundborg, 1970). If trauma is added to ischaemia the swelling is greater than with either alone (Duncan and Blalock, 1943). There is no record in the literature of the minimum time a tourniquet needs to be applied to produce detectable oedema. In our patients, as opposed to animals, oedema probably results from tourniquet ischaemia to an extent related to its duration. During operation under tourniquet, however, oedema does not develop and the advantage gained by its proper use may outweigh the consequence unless abused. The presence of a protein-rich exudate in tissue spaces, increased in quantity by ischaemia, in addition to injury, can only contribute to stiffness of the hand and impair the mobility we prize so much. The Hand--Vol. 5
No. 2
1973
121
The Tourniquet: Instrument or W e a p o n ? - - R o y Sanders HOW L O N G M A Y W E L E A V E THE T O U R N I Q U E T I N F L A T E D ?
Bruner (1951) claims that a tourniquet time of twenty to thirty minutes presents no problem in respect of oedema. After fifty to sixty minutes oedema of significant degree arises in a few susceptible patients. After one or two hours he suggests that the tourniquet should be periodically released to decrease the oedema consequent upon the ischaemia. HOW C A N W E LIMIT THE D I S A D V A N T A G E O U S EFFECT OF ISCHAEMIA?
The simplest limiting factor is "tourniquet time". Careful preoperative planning will reduce time wasted after application of the tourniquet. Release of the tourniquet as soon as our dissection and repair is performed, although inconvenient, and aesthetically unpleasing should be mandatory. Infusion of heparin with dextran in saline ten minutes before release of the tourniquet has been shown (Rhea, 1961) in dogs to reduce oedema and palsy by fifty per cent (Paletta, 1960, Shehadi, 1961). Preoperative cooling of the ischaemic limb greatly increases nerve conduction (Paletta, 1960) and decreases oedema (Shehadi, 1961) and results in more rapid recovery of circulation after release of the tourniquet. These adjuncts may be employed if prolonged ischaemia is intended or enforced. Allen (1939) showed that warming the limb during the period of ischaemia greatly increases the mortality of dogs subjected to tourniquet. Thus local heat should be used with great care. Remembering that most of the oedema will develop in the two hours after tourniquet release, each operation should end with the application of a firm, safe well-padded dressing, as a compliment to a careful dissection made possible by a controlled, safe well-padded tourniquet. SUMMARY
I. Nothing but a pneumatic arterial tourniquet should be selected. 2. It should be applied o n l y to the well-padded proximal segment of the limb. 3. It may be used in conjunction with a venous tourniquet above and below knee or elbow. 4. Care should be taken with exsanguination in patients with decompensated cardiac function. 5. It should be inflated to, and maintained at a pressure approximately 70 ram. Hg. above systolic pressure. 6. It should be inflated for no more than one hour and then deflated for at least ten minutes before reinflation. 7. At least ten minutes should be allowed for spontaneous haemostasis to occur. 8. Careful preoperative planning and dextrous dissection will reduce tourniquet time and therefore reduce swelling and stiffness. 9. All operations on the hand, especially under tourniquet, should be complemented with a firm well-padded dressing and high elevation for five days. ACKNOWLEDGEMENT
I would like to acknowledge the help in this work of Mr. B. D. G. Morgan, and the inspiration and guidanceof Mr. S. H. Harrison. 122
The H a n d - - V o l . 5
No, 2
1973
The Tourniquet: Instrument o1" Weapon?--Roy Sanders
REFERENCES BRADFORD, E. M. W. (1969) Haemodynamic changes associated with the application of lower limb tourniquets. Anaesthesia, 24: 190-197. BRUNER, J. M. (19511 Safety Factors in the Use of the Pneumatic Tourniauet for Hemostasis in Surgery of the Hand, Journal of Bone and Joint Surgery, 33A: 22-1-224. CAMPBELL, W. C. (1956) In Campbell's Operative Orthopaedics, London, Henry Kimpton 3rd Edition. Chapter 4 Surgical Technic. 129-191. CUSHING, H. (1904) Pneumatic Tourniquets: with Especial Reference to their use in Craniotomies. Medical News, New York 84: 577-580. DUNCAN, G. W. and BLALOCK, A. (1943) The effects of the application of a tourniquet on the general response to gross trauma to an extremity. Surgery, 13: 401-405. FREEBURG, B. R. and HYMAN, C. (1960) Blood-borne vasodilating agent from ischemie tissues. Journal of Applied Physiology, 15: 1041-1045. EURLOW, J. T. Jr. (1971) Cause and Prevention of Tourniquet Ooze. Surgery, Gynecology and Obstetrics, 132: 1069-1072. GRIFFITHS, J. C. and HAMILTON, P. H. (1970) The Esmarch Bandage as a Tourniquet. Journal of the Royal College of Surgeons of Edinburgh, 15: 114-117. HAMILTON, W. K., and SOKOLL, M. D. (1967) Tourniquet Paralysis. Journal of the American Medical Association, 199: 37. HINMAN, F. Jr. (1945) The rational use of tourniquets. International Abstracts of Surgery, 81: 357-366. LUNDBORG, G. (1970) Ischemic nerve injury: Experimental studies on intraneural microvascular pathophysiology and nerve function in a limb subjected to temporary circulatory arrest. Scandinavian Journal of Plastic and Reconstructive Surgery, Supplement 6. McGREGOR, I. A. (1960) Fundamental Techniques of Plastic Surgery and their Surgical Application. Edinburgh, E. & S. Livingstone p. 150. MOLDAVER, J. (1954) Tourniquet Paralysis Syndrome. Archives of Surgery 68: 136-144. NAKAHARA, M. and SAKAHASHI, H. (1967) Effect of Application of a Tourniquet on Bleeding Factors in Dogs. Journal of Bone and Joint Surgery, 49 A: 1345-1351. PALETTA, F. X., WILLMAN, V., and SHIP, A. G. (1960) Prolonged Tourniquet Ischaemia of Extremities. Journal of Bone and Joint Surgery, 42 A: 945-950. POCHIN, E. E. (1942) Oedema following ischaemia in the rabbit's ear. Clinical Science, 4: 341-347. RHEA, W. G. Jr. and FOSTER, J. H. (1961) A study of the influence of heparin and low molecular weight dextran on tourniquet palsy. Surgical Forum, 12: 437-438. SHEHADI, S., PALETTA, F. X. and COOPER, T. (1961) Effect of hypothermia on circulatory responses in the canine hind limb after tourniquet ischemia. Surgical Forum, 12466-468. THOMPSON, C. J. S. (1942) The History and Evolution of Surgical Instruments Ch 10, Tourniquets, New York, Schuman's, p. 84-88. WALKER, J. W., PALETTA, F. X. and COOPER, T. (1960) The relationship of postischemic histopathological change to muscle and subcuticular temperature patterns in the canine extremity. Surgical Forum 10: 836-838.
The Hand--Vol. 5
No. 2
1973
123
THE TOURNIQUET. INSTRUMENT
OR WEAPON?
R O Y SANDERS, Northwood, Middlesex We owe the term tourniquet to " L e grand" Petit who in 1718 engineered a screw compression device and first used the word "tourniquet" to describe it. Perhaps it is as well that only the term has persisted in daily use by hand surgeons. The original Esmarch bandage was a rubber tube the thickness of a finger and was later modified by von Langenbeck to its present form (Thompson, 1942). Griffiths (1970) pointed out that it is popular because it is convenient and easy to apply. It is always effective, probably because the pressure is too high; and it does not fail during operation. It is more stable than other tourniquets when applied to a flabby conical limb, but there is no British Standard for such tourniquets. They are usually 9 ft. (2,743 mm.) long, 3 ins. (76 ram.) wide and 155 in. (1.016 ram.) thick. Neither is there a standard arm to which it may be applied, nor a standard surgeon to apply it. Griffiths found that four turns on a limb of 15 ins. (382 ram.) circumference exerted an average pressure of 280 ram. Hg. We shall see later whether this is adequate and safe. A tourniquet, to be safe, should exert uniform and controlled pressure over a wide area. Harvey Cushing (1904), realised this. Having seen several paralyses resulting from too prolonged and energetic use of the elastic tourniquet, he developed the pneumatic tourniquet. This tool, although sometimes inconvenient and unreliable, provides the safest form of surgical ischaemia if properly padded; inflated to a known pressure; and observed by an interested anaesthetist. THE SITE OF APPLICATION OF THE TOURNIQUET
The tourniquet is most safely applied to that part of the limb which is of maximum circumference, and well padded with periosseous muscle. This is the most proximal part of the limb. Whereas it would be best to limit the ischaemia to the operative field only, this is usually, and unfortunately, the most distal part of the limb. Safety overrules convenience. Tourniquets should never be applied distal to knee or elbow. A pressure of 700 ram. Hg. in the cuff around a rabbit's thigh exerts a pressure of only 110 ram. Hg. on the sciatic nerve (Lundborg, 1970). Even in the presence of high pressure in a small limb the nerve is well protected. The circumference of the distal part of the limb is too small, and the nerves too vulnerable to 1ocalised high pressures for a tourniquet to be applied there. The dark venous and capillary ooze which occurs too often at the critical operative moment is usually blamed on a snoozing, smoking or coffee drinking anaesthetist who is alleged to have allowed the cuff to deflate. Furlow (1971) offers another explanation. He applied a tourniquet to the most proximal part of the limb of anaesthetised dogs and carried out amputations at various levels. Amputation just below the tourniquet caused venous ooze from the bony medulla only. Amputation at the elbow caused ooze from the muscle only. If the humerus was stripped of muscle below the tourniquet blood dripped from the veins emerging through the cortex of the lower end of the humerus. Thus the ooze is due to blood entering the bony medulla through nutrient arteries in the most proximal part of the limb. It escapes beneath the occluding tourniquet through the veins of the medulla, and emerges distally through the cortex into the muscular veins, and thence to our operative field. This "Medullary Bypass" is the cause of a bloody operation in the presence of an " a d e q u a t e " tourniquet. The solution is either to apply an arterial tourniquet at the level of the elbow which is unsafe, or to apply an arterial tourniquet proximally, and a venous one above and below the elbow. Pressure over bony structures is avoided and haemostasis is complete. The H a n d - - V o l . 5
No. 2
1973
119
7"he Tourniquet: Instrument or Weapon?--Roy Sanders EXSANGUINATION
Whether the vessels are empty of blood during operation will depend upon the preferences of the surgeon, and upon the operation being performed. Exsanguination has not been shown in the short or long term to be deleterious to the tourniquet limb, nor advantageous either. Bradford (1969) has shown that with the application of bilateral exsanguinating tourniquets to the lower limbs 700-800 mls of blood will be added to the remaining circulation of an adult patient. The central venous pressure m a y rise to a m e a n value of 17.5 cm water and when applied to one lower limb only, central venous pressure m a y rise to a mean value of 9.7 cm for five minutes. There is then a slow fall to resting levels. Exsanguination of one upper limb causes a rise of central venous pressure to 6 cm water, and a fall below zero on release. Without exsanguination no change in central venous pressure occurs on application or release of the pneumatic tourniquet. Thus care needs to be taken in cases where congestive cardiac failure is imminent or present, lest by exsanguination of one or more limbs a rapid increase of central venous pressure precipitates or exacerbates cardiac failure. PRESSURE I N THE C U F F
It has been empirically stated (Campbell, 1956) that m a x i m u m safe pressure for upper limb tourniquets is 300 ram. Hg., and for the lower limb 500 ram. Hg. Would it not be more sensible to use the m i n i m u m e~ective pressure rather than the m a x i m u m safe pressure? Clearly tourniquet pressure needs to be greater than arterial pressure. The arterial pressure m a y rise during surgery. H i n m a n (1945) noted rises in arterial pressure above preoperative levels of up to 70 ram. Hg. Thus a vigilant anaesthetist could maintain such a m i n i m u m effective pressure using a m e r c u r y manometer. The use of aneroid gauges m a y lead to disaster and to avoid such a possibility a safety device, like a pressure cooker valve which exhausts at known pressure, m a y be used (Hamilton and Sokoll, 1967). M a n y causes of tourniquet paralysis appear in the literature, and the number of reported cases has decreased with increased use of the pneumatic tourniquet (Moldaver, 1954). All types of tourniquet have been blamed but in each case the pressure was too high, or applied for too long. F o r years the debate has gone on as to whether nerve palsies are due to localised pressure or distal isehaemia. Lundborg (1970) has shown that ischaemia alone, for as much as six hours did not result in injury to walls of endoneural vessels sufficient to give rise to an extravascular leakage of albumin. Eight to ten hours of ischaemia were necessary for this to occur. In the compressed nerve segment, a prominent leakage of albumin f r o m endoneural vessels occurred after four hours cuff compression. Recovery of nerve conduction after two hours of ischaemia was rapid, but one hour after a limb had been subjected to two hours of compression and isehaemia, there was only minimal return of nerve excitability. Thus, localised compression of the nerve segment is the principal pathogenic factor in the production of nerve lesions after the use of a tourniquet. It should be r e m e m b e r e d that localised high pressure of a nerve against a bony prominence is more likely to produce injury than if the nerve is protected by a large muscle mass. In respect of nerve lesions therefore, it is the effective pressure of the tourniquet which is so critical. The correct pressure is the minimal pressure required to produce a bloodless field, and should not need to exceed preoperative systolic pressure by much more than 70 ram. Hg. 120
The Hand--Vol. 5
No. 2
1973
The Tourniquet: Instrument or Weapon?--Roy Sanders C H A N G E S O C C U R R I N G D U R I N G THE P E R I O D OF I S C H A E M I A
There are no significant microscopic or haematological changes in the ischaemic limb in animals or man during tourniquet times of less than four hours. The skin temperature of arms subjected to tourniquet falls by 1.5°C during one hour of ischaemia, and then rises above preoperative levels by a similar or greater margin on release. A spotlight and theatre light, in my experience, does not prevent this fall. CONSEQUENCES OF THE R E L E A S E OF THE T O U R N I Q U E T
Increased B l e e d i n g : -
By using a tourniquet we achieve a bloodless field during surgery, but pay the price on release. The phenomenon of reactive hyperaemia is well known. It may be used to advantage, as in McGregor's "tourniquet test" as a method of estimation of skin viability in degloving injuries (McGregor, 1960). More often it proves troublesome in that bleeding from damaged tissues seems to be increased. Nakahara (1967) confirmed a significant increase in bleeding tendency in dogs after tourniquet release. They found that it was greatest immediately after release, but still three times normal ten minutes later. We need to wait longer with gentle pressure for spontaneous haemostasis therefore than with a similar situation in a non-ischaemic wound. Blood coagulation time is increased immediately after release, is maximum five minutes later and significantly raised for at least one hour after release (Nakahara, 1967), and so offsets in part the vasodilatation. Many authors recommend the release of a tourniquet at hourly intervals, or less. On release of a tourniquet there is an initial phase when the blood flow is less than resting levels, probably due to a reflex vasoconstriction (Freeberg and Hyman, 1960) and the period of reduced flow tends to be proportional to the duration of ischaemia. If the tourniquet is to be reinflated after two hours ischaemia, it seems likely that at least ten minutes should be allowed before reinflation, for return of normal circulation (Walker, Paletta and Cooper, 1960). Swelling:-
The puffy, stiff hand is sometimes seen after operation under tourniquet. It is worthwhile to establish whether the tourniquet contributes to this oedema. Most of the experimental work into the cause and extent of tourniquet 0edema has been carried out on animals, with limb tourniquets applied for long periods. In the absence of added accidental or surgical trauma the swelling occurs within ten minutes of the release of the tourniquet (Paletta, 1960), and contains up to five per cent of proteins (Pochin, 1942). It is usually maximal at two hours and disappears after about one week (Lundborg, 1970). If trauma is added to ischaemia the swelling is greater than with either alone (Duncan and Blalock, 1943). There is no record in the literature of the minimum time a tourniquet needs to be applied to produce detectable oedema. In our patients, as opposed to animals, oedema probably results from tourniquet ischaemia to an extent related to its duration. During operation under tourniquet, however, oedema does not develop and the advantage gained by its proper use may outweigh the consequence unless abused. The presence of a protein-rich exudate in tissue spaces, increased in quantity by ischaemia, in addition to injury, can only contribute to stiffness of the hand and impair the mobility we prize so much. The Hand--Vol. 5
No. 2
1973
121
The Tourniquet: Instrument or W e a p o n ? - - R o y Sanders HOW L O N G M A Y W E L E A V E THE T O U R N I Q U E T I N F L A T E D ?
Bruner (1951) claims that a tourniquet time of twenty to thirty minutes presents no problem in respect of oedema. After fifty to sixty minutes oedema of significant degree arises in a few susceptible patients. After one or two hours he suggests that the tourniquet should be periodically released to decrease the oedema consequent upon the ischaemia. HOW C A N W E LIMIT THE D I S A D V A N T A G E O U S EFFECT OF ISCHAEMIA?
The simplest limiting factor is "tourniquet time". Careful preoperative planning will reduce time wasted after application of the tourniquet. Release of the tourniquet as soon as our dissection and repair is performed, although inconvenient, and aesthetically unpleasing should be mandatory. Infusion of heparin with dextran in saline ten minutes before release of the tourniquet has been shown (Rhea, 1961) in dogs to reduce oedema and palsy by fifty per cent (Paletta, 1960, Shehadi, 1961). Preoperative cooling of the ischaemic limb greatly increases nerve conduction (Paletta, 1960) and decreases oedema (Shehadi, 1961) and results in more rapid recovery of circulation after release of the tourniquet. These adjuncts may be employed if prolonged ischaemia is intended or enforced. Allen (1939) showed that warming the limb during the period of ischaemia greatly increases the mortality of dogs subjected to tourniquet. Thus local heat should be used with great care. Remembering that most of the oedema will develop in the two hours after tourniquet release, each operation should end with the application of a firm, safe well-padded dressing, as a compliment to a careful dissection made possible by a controlled, safe well-padded tourniquet. SUMMARY
I. Nothing but a pneumatic arterial tourniquet should be selected. 2. It should be applied o n l y to the well-padded proximal segment of the limb. 3. It may be used in conjunction with a venous tourniquet above and below knee or elbow. 4. Care should be taken with exsanguination in patients with decompensated cardiac function. 5. It should be inflated to, and maintained at a pressure approximately 70 ram. Hg. above systolic pressure. 6. It should be inflated for no more than one hour and then deflated for at least ten minutes before reinflation. 7. At least ten minutes should be allowed for spontaneous haemostasis to occur. 8. Careful preoperative planning and dextrous dissection will reduce tourniquet time and therefore reduce swelling and stiffness. 9. All operations on the hand, especially under tourniquet, should be complemented with a firm well-padded dressing and high elevation for five days. ACKNOWLEDGEMENT
I would like to acknowledge the help in this work of Mr. B. D. G. Morgan, and the inspiration and guidanceof Mr. S. H. Harrison. 122
The H a n d - - V o l . 5
No, 2
1973
The Tourniquet: Instrument o1" Weapon?--Roy Sanders
REFERENCES BRADFORD, E. M. W. (1969) Haemodynamic changes associated with the application of lower limb tourniquets. Anaesthesia, 24: 190-197. BRUNER, J. M. (19511 Safety Factors in the Use of the Pneumatic Tourniauet for Hemostasis in Surgery of the Hand, Journal of Bone and Joint Surgery, 33A: 22-1-224. CAMPBELL, W. C. (1956) In Campbell's Operative Orthopaedics, London, Henry Kimpton 3rd Edition. Chapter 4 Surgical Technic. 129-191. CUSHING, H. (1904) Pneumatic Tourniquets: with Especial Reference to their use in Craniotomies. Medical News, New York 84: 577-580. DUNCAN, G. W. and BLALOCK, A. (1943) The effects of the application of a tourniquet on the general response to gross trauma to an extremity. Surgery, 13: 401-405. FREEBURG, B. R. and HYMAN, C. (1960) Blood-borne vasodilating agent from ischemie tissues. Journal of Applied Physiology, 15: 1041-1045. EURLOW, J. T. Jr. (1971) Cause and Prevention of Tourniquet Ooze. Surgery, Gynecology and Obstetrics, 132: 1069-1072. GRIFFITHS, J. C. and HAMILTON, P. H. (1970) The Esmarch Bandage as a Tourniquet. Journal of the Royal College of Surgeons of Edinburgh, 15: 114-117. HAMILTON, W. K., and SOKOLL, M. D. (1967) Tourniquet Paralysis. Journal of the American Medical Association, 199: 37. HINMAN, F. Jr. (1945) The rational use of tourniquets. International Abstracts of Surgery, 81: 357-366. LUNDBORG, G. (1970) Ischemic nerve injury: Experimental studies on intraneural microvascular pathophysiology and nerve function in a limb subjected to temporary circulatory arrest. Scandinavian Journal of Plastic and Reconstructive Surgery, Supplement 6. McGREGOR, I. A. (1960) Fundamental Techniques of Plastic Surgery and their Surgical Application. Edinburgh, E. & S. Livingstone p. 150. MOLDAVER, J. (1954) Tourniquet Paralysis Syndrome. Archives of Surgery 68: 136-144. NAKAHARA, M. and SAKAHASHI, H. (1967) Effect of Application of a Tourniquet on Bleeding Factors in Dogs. Journal of Bone and Joint Surgery, 49 A: 1345-1351. PALETTA, F. X., WILLMAN, V., and SHIP, A. G. (1960) Prolonged Tourniquet Ischaemia of Extremities. Journal of Bone and Joint Surgery, 42 A: 945-950. POCHIN, E. E. (1942) Oedema following ischaemia in the rabbit's ear. Clinical Science, 4: 341-347. RHEA, W. G. Jr. and FOSTER, J. H. (1961) A study of the influence of heparin and low molecular weight dextran on tourniquet palsy. Surgical Forum, 12: 437-438. SHEHADI, S., PALETTA, F. X. and COOPER, T. (1961) Effect of hypothermia on circulatory responses in the canine hind limb after tourniquet ischemia. Surgical Forum, 12466-468. THOMPSON, C. J. S. (1942) The History and Evolution of Surgical Instruments Ch 10, Tourniquets, New York, Schuman's, p. 84-88. WALKER, J. W., PALETTA, F. X. and COOPER, T. (1960) The relationship of postischemic histopathological change to muscle and subcuticular temperature patterns in the canine extremity. Surgical Forum 10: 836-838.
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No. 2
1973
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