gms | German Medical Science

Compared with common burn injuries, high voltage injuries are caused by thermic tissue trauma as well; in contrast, though, extent and severity are not sufficiently assessable by mere inspection of the affected body surface area. In order to accurately evaluate the total suffered tissue damage, intracorporal areas affected by the high voltage current are at least equally significant and therefore have to be taken into account. The variables determining the total damage are current voltage and amperage, duration and area of contact as well as resistance of the concerning tissue [2]. In contrast to the types of affected human tissue, above stated factors are highly variable. Electric currents usually flow towards areas with little resistance, i.e. tissues with high electric conductivity like dermal, neurovascular and particularly muscular tissues [2].

Posttraumatic development of rhabdomyolisis after high voltage injuries, especially in the upper and lower extremities, is a highly significant prognostic factor: Due to the hazardous electric currents causing muscular and neurovascular necrosis, known haemorheologic alterations in the blood flow occur leading to massive edema of the extremities. In regions with stiff muscle surrounding fasciae, such as the crural or forearm compartments, this can cause compressive compartment syndrome with additional tissue loss due to the increasing pressure and consecutive malperfusion within the first couple of hours. Only sufficient decompression can stop the progressing vicious cycle, hence operative therapy is indicated as soon as possible.

In intubated Patients, accurate clinical criteria of a suspected compartment syndrome are rarely found. Therefore, continuous monitoring including parameters indicating rhabdomyolysis such as serum creatine kinase (CK) and assessment of brown urine (myoglobinuria), which is known to correlate with myoglobinaemia caused by massive muscular tissue loss, was performed. If compartment syndrome is suspected, positive findings of the above stated diagnostics are highly relevant and immediate operative decompressive fasciotomy is indicated.

Rapid diagnostics as well as sufficient fasciotomy are highly significant for the patients’ overall-survival; decreasing the risk of renal and cardial complications due to the known nephrotoxic potential of myoglobin and cardiac arrythmia caused by elevated potassium levels after necroptosis, respectively. Moreover the incidence of septic complications is reduced.

An 18-year-old patient in intoxicated condition climbed a railway waggon at night. On top, he was struck by an electric arc from the trolley wire charged with 15,000 volts and fell from the waggon headfirst. Initially the patient was responsive, so he could be transferred to the next hospital. Initial clinical examination revealed 3^rd degree burns affecting 50% of the total body surface area (TBSA), so immediate rescue-helicopter-transfer to our Burns Center was organized. After 3 hours of transport, the patient was admitted protectively intubated. In the mean time monocle haematomas in both periorbital had developed; the ordered craniocervical CT-scans revealed a complex midface fracture involving the zygomatic bone, maxilla and the orbital floor. No additional traumatological injuries, especially no intracranial lesions, were found.

In our Burns Center, clinical evaluation revealed 20% 2a degree and 13% 2b degree burns, totaling 33% TBSA with affected areas of the head, neck, ventral torso, left thigh and entire right leg (Figure 1 [Fig. 1]). The right leg showed 2b degree burn injuries, upon palpation, though, the integument was flaccid, foot pulses were palpable, no signs of compartment syndrome could be found. The abbreviated burn severity index (ABSI) scored six points at the time. One hour after admission to our hospital, four hours after the suffered trauma, respectively, immediate necrosectomy in the burns cleaning bath was performed and the patient was transferred to our burns intensive care unit (BICU).

7.5 hours after trauma, a notably high serum CK concentration was detected (Figure 2 [Fig. 2]), yet, all extremities remained inconspicuous concerning compartment syndrome. Upon monitoring of the thigh circumferences a 1 cm increase on the right side was noticed. The increase of serum CK and myoglobinuria taken into account, diagnosis of a progressing compartment syndrome was confirmed. Accurate localization oft the affected area in the limbs could not be determined with clinical criteria, so that excessive preventive decompression of both extremities had to be considered. Because of the patient’s considerable morbidity we decided to order an emergency whole-body MRI-scan to ascertain the location first; it was performed 10.5 hours post trauma (sequential mode: neck, thorax , abdomen, pelvis, thigh, lower leg in SPiR, SPAIR und T1 coronal). Edematous fluid accumulations with corresponding intramuscular hyperintensity of the thigh (M. quadriceps femoris, M. adduktor longus) and the three crural compartments of the right leg were revealed (Figure 3 [Fig. 3]). Consequently the indication for targeted decompressing fasciotomy was set, but limited to the earlier defined areas. The operation was performed 12.5 hours post trauma; intraoperatively macroscopic signs of muscle ischemia showed, but regressed throughout the procedure (Figure 4 [Fig. 4] and Figure 5 [Fig. 5]). Thus, urgent and sufficient operative decompression was ensured, which could be monitored as decreasing serum CK concentrations (Figure 2 [Fig. 2]).

After 25 days of intensive care and another five surgical interventions, the patient was transferred to the normal ward. Postoperatively a complete motoric and sensational failure of the right leg had developed which regressed spontaneously throughout his stay. Six months after the suffered trauma no residual neurologic deficits were detectable (Figure 6 [Fig. 6]).

Unlike in traumatology, localization of the compressing compartment in high voltage injured patients based exclusively on diagnostics like serum CK and myoglobinuria (Figure 7 [Fig. 7]) can be difficult. Therefore preventive fasciotomy of all assumed compartments is recommended [7]. However, an increase of survival could not yet be proven, hence, recommendation of preventive fasciotomy is today relativized [5]. Furthermore, there is even evidence that selective decompression is effective preventing secondary malperfusion caused by compartment syndrome. But amputation cannot be avoided in every case, since the decision is primarily dependent on the extent of the trauma [4]. In this respect, the significance of intracompartmental pressure monitoring is investigated; there are authors who set indication for operative decompression, others explicitly do not decide based on an increase of the monitored pressure [5]. This matter is also thoroughly discussed in traumatology. As opposed to the other forms of compartment syndrome, absence of palpable pulses in high voltage injured patients does not occur regularly [7], therefore it might be important to pay particular attention to peripheral pulse monitoring.

Since accurate localization of the affected compartment based on clinical parameters is difficult, full body MRI-investigation might be useful to decide exactly where operative decompression is indicated. The current data is not encouraging, though: Back in 1995, Fleckenstein et al. reported about a high voltage injured patient intending to evaluate vitality of muscular tissue [1]. Edematous alterated muscles without enhancement, and therefore inadequate haemoperfusion, were defined non-vital, whereas enhanced tissue was categorized vital. Yet, they also concluded that in MRI-investigation, non-vital non-edematous muscular substance cannot be distinguished from normal tissue, which compromises sensitivity of this method. Ohashi et al. showed that MR-imaging can be used to determine extremity amputation levels in the high voltage injured [6]. Recently, MRI was increasingly regarded as an early-phase-detection-tool for muscular tissue necrosis [3], however confirming data are yet to be published. In this regard, accurate early phase imaging for detection of compartment syndrome is not yet empirically established [5].

Modern 1.5-Tesla-Multichannel-MRIs with movable patient tables allow high resolution full-body-scans in less than thirty minutes without repositioning of the patient. Usually full-body-scans are recommended for early detection, follow up and staging diagnostics of tumors but can also be useful in benign diseases [8].

In instable acute patients every examination outside of the BICU is considered potentially risky, therefore indications should be thoroughly reflected. Some authors consider serum CK a sufficient parameter to diagnose compartment syndrome and consecutively justify operative decompression [3]. But like stated in our case report, localization of the compartment based on mere clinical criteria is slightly impossible. Hence, stable patient conditions and appropriate institutional circumstances provided, we recommend early stage full body MRI-investigation for a sparing but more accurate approach.

Our case report shows that, in contrast to older devices, new generation MRI-scanners are capable of detecting locally defined compartment areas in a short amount of time. Hence, the indicated decompressive faciotomy can be limited to the defined locus and excessive preventive procedures are unnecessary. Decreased morbidity may justify monetary and logistic efforts.

The authors declare that they have no competing interests.