Tourniquet application is considered an effective and easily applied (by medical and nonmedical personnel) method for prevention of exsanguination in military prehospital settings.1-3 According to Israeli Defense Force protocols, there are several indications for tourniquet application on the battlefield, including (1) amputation of a limb, (2) multiplesite injury, (3) uncontrolled bleeding from a major limb vessel, (4) multiple-casualty event, and (5) night scenario.
Tourniquets are widely used in medical settings, particularly in orthopedic and vascular limb procedures. Pressure slightly higher than systolic pressure is induced by using an ad hoc sphygmomanometer (one designed especially for this purpose) and is applied proximal to the surgical area for a restricted period of time (usually no longer than 2 hours). Complications of tourniquet placement such as neuropraxia and nerve paralysis4 attributable to direct nerve pressure or ischemia,5 rhabdomyolysis,6 compartment syndrome,7 increased intravascular coagulation,8 and limb ischemia are well known. Tourniquet-induced reperfusion injury is an event known to produce a significant systemic inflammatory effect..910 To date, there is a paucity of literature regarding the indications for and complications of prolonged tourniquet application on the battlefield. Lakstein et al.3 described a 4-year retrospective analysis of silicone and improvised tourniquet applications used in battle by Israeli Defense Force soldiers with almost no complications. Volpin et al.11 described an anecdotal case of nerve paralysis following prolonged use of a tourniquet.
We describe five cases involving soldiers wounded in different battles during the conflict between Israeli and Hezbollah troops in Lebanon in 2006. All soldiers arrived at the emergency department (ED) after prolonged periods of limb tourniquet application. In each case, evacuation of the wounded soldier was delayed because of the inability of rescue forces to reach the battle site earlier.
A 20-year-old male soldier was transported to the ED from the battlefield after he sustained a proximal arm bullet injury. Immediately after the injury, an army medic placed a tourniquet on the wounded arm just distal to the bullet entrance wound (Fig. 1). Overall, tourniquet time was -10 hours, the approximate time it took for a rescue to be completed. Soon after arrival at the ED, the tourniquet was removed. While on the battlefield, the soldier complained of decreased sensation in the ulnar and radial nerve supply regions of his wounded arm and total anesthesia in the median nerve supply zone distal to the area of tourniquet placement. Physical examination in the ED showed a slight reduction in wrist and finger extension power (4 of 5), and laboratory studies indicated an elevated creatine phosphokinase level (>1,400 U/L). In the 3 weeks of follow-up monitoring after the incident, neurological function improved gradually to normal, and no consequence of rhabdomyolysis was seen.
A 20-year-old male soldier was brought to the ED from the battlefield after he sustained a bullet injury to his thigh. No major bleeding was observed by army medics; however, a tourniquet was placed proximal to the injury site. Upon arrival at the ED, there was evidence of overt cyanosis of the affected limb, which was thought to have occurred because of inadequate induced pressure, which allowed for venous rather than arterial occlusion (Fig. 2). The patient complained of hypoesthesia in the entire leg distal to the region of tourniquet placement. Overall tourniquet time was 12 hours. During that period, the tourniquet remained in place and the wound was never examined for continued bleeding. After tourniquet removal in the ED, skin color rapidly returned to normal, and no neurovascular damage was observed in the physical examination. Creatine phosphokinase levels were high (> 1,000 U/L), but kidney function remained unaffected in follow-up evaluations. Sensation gradually returned to normal by follow-up day 5.
A 22-year-old male soldier was brought to the ED from the battlefield after he sustained a bullet injury to the proximal leg. Soon after the injury, a medical doctor serving on the battlefield placed a tourniquet above the knee and a pressure bandage on the wound distal to the tourniquet. The physician, noticing a visible spot of blood soaking through the pressure bandage, then placed a second pressure bandage on top of the first, without first exploring the wound or assessing the bleeding. Both the tourniquet and pressure bandages remained in place for >20 hours while the unit waited for evacuation. Throughout the entire period until arrival at the ED, the wound was not assessed for continued bleeding. After arrival at the ED, the tourniquet and the pressure bandages were removed and a neurological examination was performed, revealing complete peroneal nerve palsy. The nerve damage was apparently caused by the pressure bandage. The creatine phosphokinase level on arrival at the ED was in the normal range (100 U/L), which leads us to think that the tourniquet was incorrectly placed.
A 22-year-old male soldier was brought to the ED from the battlefield after he sustained a gunshot injury to the distal tiiird of his right arm and multiple shrapnel wounds to his forearm and hand. A tourniquet had been applied to the injured arm by an army medic in the field. Upon arrival at the ED, radial nerve palsy was seen in the neurological examination. The tourniquet was removed, and the patient was transferred to the operating room for surgical exploration of the wound. Except for a minimal amount of bleeding from a small branch of the radial artery, no major hemorrhage was found. In addition to the vascular repair, a fasciotomy was performed to correct the compartment syndrome that had developed in the injured forearm. Surgical exploration of the radial nerve was also performed, revealing it to be contused and continuous.
A 22-year-old male soldier was brought to the ED from the battlefield after he sustained a traumatic amputation of the right leg. The level of the amputation was 5 cm below the knee. A tourniquet applied just above the knee was left in place for ~11 hours because of problems with evacuation from the battlefield. In the operating room, the patient required an above-knee amputation. The knee could not be preserved because of severe muscle damage and soft tissue problems associated with the extended tourniquet application (Fig. 3).
In this study, we present five cases of nerve damage induced by prolonged tourniquet placement. Although an indication for tourniquet application existed in all of the cases, placement was performed either incorrectly or inefficiently for proper arterial occlusion and for too long a period before removal, during which time there was no exploration of the wound or evaluation of any continued blood loss. When patients did complain of pain and decreased sensations in the wounded limb, which under normal conditions would have alerted the caregivers to signs characteristic of ischemia and nerve damage, the patients were given analgesics. Furthermore, for most of the time that each injured soldier was waiting for evacuation, no fighting was taking place; this means that the medical team was fully available to reexamine and to evaluate the wounded site for any continued bleeding and to adjust the tourniquet accordingly.
The battlefield setting offers a unique environment for the treatment of injuries. It is characterized by a high degree of stress and by conditions that are extremely difficult for die proper evaluation and treatment of combat injuries. To our knowledge, only one previously published, retrospective study assessed the efficiency of tourniquet application on the battlefield. That study found that tourniquet use can be effective and easy and is best when tourniquets are applied by medical doctors.3 However, the time periods during which the tourniquets were in place in that study were short (1-300 minutes), compared witii our cases.
Excessive pressure and long duration of nerve ischemia are the two main factors causing nerve injury.12 After an experimental investigation in dogs, it was recommended that a pneumatic tourniquet not be left inflated for periods of >75 minutes.13 In human research, experiments have shown that nerve conduction velocities always return to within normal ranges if the tourniquet is not inflated for >2 hours and pressure does not exceed 500 mm Hg.14 Accordingly, it seems reasonable to suggest that, in cases where a tourniquet is required to be in place for >2 hours, the tourniquet should be loosened for short intervals. If the patient's condition is stable and release of the tourniquet does not restart the bleeding, then a change to a pressure bandage is mandatory."
Tourniquet types routinely used in the field are strips of either rubber or silicone (for the upper limb and leg) or an improvisation consisting of a large bandage and two sticks (for the thigh) (Fig. 3). Monitoring of induced pressure is impossible. Consequently, because the surface area under the tourniquet is small, nerves may be subjected to areas of extremely high pressure,15 with subsequent crush injury. In other cases, the pressure exerted by the tourniquet may be too low, causing venous occlusion, which can lead to increased blood loss if other proximal bleeding wounds exist. A need exists for a commercial sphygmomanometer cuff with a large surface area that is suitable for application to all limb parts. This would allow for the use of lower pressures,16 better pressure control, temporary release, and safe constant decreases in pressure to the minimal pressure necessary. In addition, because of its large contact surface, the cuff would cause less soft tissue and neural damage.17
It is widely recognized tiiat the vast majority of medical doctors who are called upon to treat emergency cases on the battlefield are not qualified in emergency orthopedic trauma medicine. Their entire qualification in trauma management currently is based on training intended to improve their trauma skills through repetitive practice and memorization of military medicine doctrines. Therefore, we think that more training is essential, with more emphasis on the proper application technique and timing of removal.18
Although the indications for placement of a tourniquet in the battlefield setting are quite reasonable and solid, indications for removal or loosening of a tourniquet in the pre-ED setting simply do not exist, which leaves untrained medical doctors in a serious conflict. Therefore, it may be justified to add the following recommendations. (1) The caregiver should remove the tourniquet and evaluate a bleeding wound every 2 hours. (2) If the bleeding is under control, then the tourniquet should be replaced by a pressure bandage. (3) Signs of impending limb ischemia (i.e., pain, dysesthesia, or changes in color) should be thoroughly sought by the caregiver. (4) Commercial tourniquets should replace the current rubber ones, which would enable precise monitoring of pressure and duration of application.
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Source: Military Medicine