Compartment syndrome: a complication of acute extremity trauma

Comparison and convergence of compartment syndrome techniques: a narrative review

INTRODUCTION

Compartment syndrome (CS) continues to be a legitimate orthopedic emergency as it leads to thousands of amputations and permanent nerve and tissue damage to undiagnosed patients for more than eight hours. In CS, intracompartmental pressure is elevated, causing reduced blood flow inside the limb compartments. An erroneous diagnosis may result in unnecessary fasciotomies, the only treatment for this condition.

AREAS COVERED

This review examines the previous and current diagnostic and therapeutic practices for compartment syndrome. It also performs a comparative analysis of each diagnostic technique and its foresights.

EXPERT OPINION

Currently, most clinicians rely on a physical examination of the patient to diagnose CS. The primary reason for the physical examination is the lack of a gold-standard device. The invasive intracompartmental pressure (ICP) measurement technique is still the most commonly used. On the other hand, many non-invasive approaches have the potential to be used as diagnostic tools; however, more research is needed before they can be accepted as standard clinical approaches.

Aetiology of trauma-related acute compartment syndrome of the leg: A systematic review

BACKGROUND

Acute compartment syndrome (ACS) is characterised by abnormal pressure inside a compartment, resulting in ischemia of muscles and nerves. Most orthopaedic surgeons, especially those who work in major trauma centres, have been or will be facing a case of ACS in their clinical activity. Fortunately, complications related to untreated compartment syndrome have become less frequent thanks to a better understanding of pathogenesis and to early recognition and prompt surgical treatment. The aim of this study is to identify the existing evidence regarding aetiology of trauma-related ACS of the leg.

METHODS

A systematic review of the literature was undertaken using PubMed Medline, Ovid Medline and the Cochrane library, extended by a manual search of bibliographies. Retrieved articles were eligible for inclusion if they reported data about aetiology of trauma-related compartment syndrome of the tibia.

RESULTS

Ninety-five studies that fulfilled the inclusion criteria were identified. By dividing the studies into three groups according to the traumatic aetiology, we were able to classify traumatic ACS as fracture related, soft tissue injury related and vascular injury related. Fracture related was the most represented group, comprising 58 papers, followed by the soft tissue injury related group which includes 44 articles and vascular injury related group with 24 papers.

CONCLUSIONS

Although traditionally ACS has been associated mainly with fractures of tibial diaphysis, literature demonstrates that other localisations, in particular in the proximal tibia, are associated with an increased incidence of this serious condition. The forms of ACS secondary to soft tissues injuries represent an extremely variable spectrum of lesions with an insidious tendency for late diagnosis and consequently negative outcomes. In the case of vascular injury, ACS should always be carefully considered as a priority, given the high incidence reported in the literature, as a result of primitive vascular damage or as a result of revascularisation of the limb. Knowledge of aetiology of this serious condition allows us to stratify the risk by identifying a population of patients most at risk, together with the most frequently associated traumatic injuries.

A cadaveric model of anterior compartment leg syndrome: Subcutaneous minimally invasive fasciotomy versus open fasciotomy

OBJECTIVE

Because of disabling sequelae of open fasciotomy in anterior compartment syndrome (ACS) of the leg, we wanted to describe and validate a cadaveric model of ACS. We hypothesized that, first, anterior compartment syndrome (ACS) could be reproduced in cadaveric leg and, second, fasciotomy without complete skin incision could lower the intramuscular pressure (IMP) in an equivalent range to complete dermatofasciotomy.

MATERIALS AND METHODS

Lower limb ACS was reproduced by progressive injection of physiologic serum in the anterior compartment of 23 fresh frozen cadaveric legs with monitoring of IMP, in order to reach a maximal stabilised IMP higher than 30mmHg. Subcutaneous minimally invasive fasciotomy was performed on 14 legs through 5 transversal mini-incisions of the skin (2cm) along the axis from the tibial tuberosity to the posterior aspect of the lateral malleolus. Standard open fasciotomy of the anterior compartment was performed on the remaining 9 legs as control. IMP was measured after the skin incisions and after every fasciotomy through skin incisions in the first group and after skin and fascia incisions in the control group.

RESULTS

A maximal IMP of 43±2mmHg was obtained by injection of 177±9ml physiologic serum into the anterior compartment of the leg. In the control open fasciotomy group, the skin incision alone did not lower IMP significantly, whereas fasciotomy lowered IMP to 10±1mmHg, which is statistically different from maximal IMP (p<0.001). In the subcutaneous fasciotomy group, complete fasciotomy lowered significantly the IMP to 11±4mmHg (p<0.001), without statistical difference with the control group.

DISCUSSION

This cadaveric model is effective to reproduce the hyperpressure encountered in ACS. In this model, IMP release after fasciotomy is as efficient through minimally invasive subcutaneous incision as with control open fasciotomy. This in vitro technique appears as an attractive alternative treatment in anterior compartment syndrome of the leg. It should be tested in the other compartments of the leg and its in vivo feasibility in acute conditions has to be clarified.

LEVEL OF EVIDENCE

III, control laboratory study.

Contemporary Management and Outcome After Lower Extremity Fasciotomy in Non-Trauma-Related Vascular Surgery

INTRODUCTION

Acute compartment syndrome (ACS) is a challenging and recognized complication to vascular surgery revascularization. The aim of this study was to investigate the current epidemiology, management, and early outcomes of fasciotomy in vascular surgery.

METHODS

Retrospective cohort study of all patients undergoing lower extremity fasciotomy at a single university center between January 2008 and December 2014. Patient demographics, operative techniques, and outcomes were analyzed.

RESULTS

The cohort (n = 113 limbs; 107 patients; 48% women; mean age was 74 (12) years [range, 50-97 years]) included 81 (72%) limbs undergoing revascularization for acute limb ischemia, 7 (6.2%) limbs related to acute aortic disease, and 23 (20%) limbs undergoing elective vascular surgery. Five patients underwent bilateral lower extremity fasciotomy. In all, 64 (57%) limbs had signs of ACS and underwent a therapeutic fasciotomy, while 49 (43%) fasciotomies were prophylactic. There were 20 (18%) fasciotomies performed after endovascular interventions. A 4-compartment fasciotomy was performed in 82% (n = 93) of limbs with a double incision technique. Split thickness skin graft was required in 11% (12/112) and vacuum-assisted closure treatment in 11% (12/111). The mean length of stay in hospital was 11 (9) days. Most common complication was lower extremity nerve deficit 32% (33/104) followed by wound infection 30% (32/108). At 30-day follow-up, amputation rate was 13% (14/107 limbs) and mortality 23% (25/107 patients). In the multivariate logistic regression analysis, prophylactic fasciotomy was associated with amputation (odds ratio: 28.9; 95% confidence interval: 1.96-425; P = .014).

CONCLUSION

Acute compartment syndrome is primarily related to acute ischemic conditions but occurs after both aortic or elective vascular procedures and endovascular treatments. There are significant complications related to lower extremity fasciotomy in vascular surgery.

Acute compartment syndrome: How long before muscle necrosis occurs?

Objectives:

Acute compartment syndrome (ACS) is a limb-threatening condition often first diagnosed by emergency physicians. Little is known about the rapidity with which permanent damage may occur. Our objective was to estimate the time to muscle necrosis in patients with ACS.

Methods:

This historical cohort analysis of all patients who had a fasciotomy for ACS was conducted in 4 large teaching hospitals. Diagnosis was confirmed clinically or by needle measurement of compartment pressure. Muscle necrosis was determined using pathology reports and surgeons’ operative protocols. We used descriptive statistics and estimated tissue survival probability using the Vertex exchange method for interval-censored data.

Results:

Between 1989 and 1997 there were 76 cases of ACS. Most cases occurred in young men (median age 32) as a result of a traumatic incident (82%). Forty-nine percent (37/76) of all patients suffered some level of muscle necrosis, and 30% (11/37) of those with necrosis lost more than 25% of the muscle belly. Necrosis occurred in 2 of 4 cases in which the patient had been operated on within 3 hours of the injury, and our exploratory survival analysis estimates that 37% (95% confidence interval, 13%-51%) of all cases of ACS may develop muscle necrosis within 3 hours of the injury.

Conclusions:

This is the largest cohort of ACS and the first clinical estimation of time to muscle necrosis ever published. Ischemia from ACS can cause muscle necrosis before the 3-hour period post-trauma that is traditionally considered safe. Further research to identify risk factors associated with the development of early necrosis is necessary.

Wound closure of leg fasciotomy: comparison of vacuum-assisted closure versus shoelace technique. A randomised study

BACKGROUND

Fasciotomies, though essential for the prevention and management of compartment syndromes, may increase morbidity and prolong hospitalisation. Two widely applied methods of delayed primary closure are compared in leg fasciotomy wounds.

PATIENTS AND METHODS

Two groups, each of 25 patients with leg fasciotomies due to fractures and soft tissue injuries, who were randomly assigned to be treated either by vacuum assisted closure (VAC®, n=42 wounds, group V) or by the shoelace technique (n=40 wounds, group S), were evaluated in this study. Wound length, time to definite closure, complications, need for additional interventions and daily treatment costs were data collected and statistically assessed.

RESULTS

Wound closure time was significantly higher in group V compared to group S (p=0.001; 95% CI of the difference, 1.8-6.3 days). Five group V patients required split thickness skin grafts. In six group S patients, the vessel loops had to be replaced. The mean daily cost of negative pressure therapy alone was 135 euro (range 117-144 euro), whilst the mean daily cost of treatment for the shoelace technique was 14 euro ranging from 8 to 18 euro (p=<0.001).

CONCLUSIONS

Both VAC® and the shoelace technique are safe, reliable and effective methods for closure of leg fasciotomy wounds. VAC® requires longer time to definite wound closure and is far more expensive than the shoelace technique, especially when additional skin grafting is required.

Crush syndrome: a case report and review of the literature

BACKGROUND

Crush trauma to the extremities, even if not involving vital organs, can be life threatening. Crush syndrome, the systemic manifestation of the breakdown of muscle cells with release of contents into the circulation, leads to metabolic derangement and acute kidney injury. Although common in disaster scenarios, emergency physicians also see the syndrome in patients after motor-vehicle collisions and patients "found down" due to intoxication.

OBJECTIVE

The objectives of this review are to discuss the pathophysiology of crush syndrome, report on prehospital and emergency department treatment, and discuss the relationship between crush syndrome and compartment syndrome.

DISCUSSION

We present the case of a young man found down after an episode of intoxication, with compartment syndrome of his lower extremity and crush syndrome. Although he eventually required an amputation, aggressive fluid resuscitation prevented further kidney injury and metabolic derangement.

CONCLUSIONS

Early, aggressive resuscitation in the prehospital setting, before extrication if possible, is recommended to reduce the complications of crush syndrome. Providers must be aware of the risk of hyperkalemia shortly after extrication. Ongoing resuscitation with i.v. fluids is the mainstay of treatment. Compartment syndrome is a common complication, and prompt fasciotomies should be performed when compartment syndrome is present.

Quantifying delays in the recognition and management of acute compartment syndrome

OBJECTIVE

To identify where most efforts should be made to decrease ischemia time and necrosis in acute compartment syndrome (ACS) and to determine the causes for late interventions.

METHODS

This was a multicentre, historical cohort study of patients who underwent fasciotomy for ACS within the McGill Teaching Hospitals between 1989 and 1997. Patients studied had a clinical diagnosis of ACS or compartment pressures greater than 30 mm Hg. In all cases, ACS was confirmed at the time of fasciotomy. Patients were stratified into traumatic and non-traumatic groups, and a step-by-step analysis was performed for each part of the process between injury and operation.

RESULTS

Among the 62 traumatic ACS cases, the longest delays occurred between initial assessment and diagnosis (median time 2h56, range from 0 to 99h20) and between diagnosis and operation (median 2h13, range 0h15-29h45). Among the 14 non-traumatic ACS cases, delays primarily occurred between inciting event and hospital presentation (median 9h19, range 0h04-289h29) and between initial assessment and diagnosis (median 8h18, range 0-104h15).

CONCLUSIONS

ACS is a limb-threatening condition for which early intervention is critical. Substantial delays occur after the time of patient presentation. For traumatic and non-traumatic ACS, increased physician awareness and faster operating room access may reduce treatment delays and prevent disability.

Sonographic evaluation of peripheral nerve injuries following the Wenchuan earthquake

PURPOSE

To analyze retrospectively the sonographic characteristics of the peripheral nerve injuries (PNIs) resulted from Wunchuan earthquake.

METHODS

The sonographic images of 38 patients with surgically proved PNIs were reviewed and compared with the surgical findings.

RESULTS

A total of 78 nerves in 38 patients were found injured in surgery, which included 16 median nerves in the forearm (20.5%), 6 ulnar nerves in the forearm or arm (7.7%), 8 radial nerves in upper limb (10.0%), 8 sciatic nerves (10.3%) in gluteal region, 17 tibial nerves in the leg (21.8%), and 23 peroneal nerves (29.5%). The most common injured nerve in the lower extremity was the peroneal nerve (29.5%) and in upper extremity was the median nerve (20.5%). Sonography correctly diagnosed 72 earthquake-related nerve injuries (92.3%), which included 5 complete disruption (6.4%), 4 partial disruption (5.1%), 63 nerve entrapment (88.5%, included 1 entrapment by bone calus, 38 entrapments by the scar tissue, 13 entrapments by the thickened muscle or tendinous arch, and 11 entrapment in the narrowed osteofibrous tunnels).

CONCLUSIONS

Nerve entrapment injury was the common sonographic finding in earthquake-related PNI.

Are certain fractures at increased risk for compartment syndrome after civilian ballistic injury?

BACKGROUND

Compartment syndrome after ballistic fracture is uncommon but potentially devastating. Few data are available to help guide clinicians regarding risk factors for developing compartment syndrome after ballistic fractures. Our primary hypothesis was that ballistic fractures of certain bones would be at higher risk for development of compartment syndrome.

METHODS

A retrospective review at a Level I trauma center from 2001 through 2007 yielded 650 patients with 938 fractures resulting from gunshots. We reviewed all operative notes, clinic notes, discharge summaries, and data from our prospective trauma database. Cases in which the attending orthopedic surgeon diagnosed compartment syndrome and performed fasciotomy were considered cases with compartment syndrome. We excluded all prophylactic fasciotomies. Univariate analyses were conducted to identify risk factors associated with development of compartment syndrome.

RESULTS

Twenty-six (2.8%) of the 938 fractures were associated with compartment syndrome. Only fibular (11.6%) and tibial (11.4%) fractures had incidence significantly higher than baseline for all ballistic fractures (p < 0.001). Fractures of the proximal third of the fibula were more likely to result in compartment syndrome than fractures of the middle or distal third (p = 0.03), as were fractures of the proximal third of the tibia (p = 0.01). No other demographic or injury parameters were associated with compartment syndrome.

CONCLUSION

Ballistic fractures of the fibula and tibia are at increased risk for development of compartment syndrome over other ballistic fractures. We recommend increased vigilance when treating these injuries, particularly if the fracture is in the proximal aspect of the bone or is associated with vascular injury.

Risk management and avoiding legal pitfalls in the emergency treatment of high-risk orthopedic injuries

Avoiding legal pitfalls of orthopedic injuries in the emergency department (ED) requires an understanding of certain high-risk injuries, their presentation, evaluation, and disposition. Various pitfalls pertaining to both upper and lower extremity injuries are discussed in detail, with recommendations regarding the history, physical examination, and radiographic techniques that minimize the risk inherent in these injuries. When approaching these injuries in the ED, a high level of suspicion coupled with appropriate evaluation and management will allow the practitioner to avoid mismanagement of these potential pitfall cases.

High-risk chief complaints III: abdomen and extremities

Abdominal and extremity complaints are a frequent reason for presentation to the emergency department. Although these are common complaints, several abdominal and extremity disease entities may be missed or may be subject to delayed diagnosis. This article provides an overview of the diagnosis and management of several high-risk abdominal and extremity complaints, including appendicitis, abdominal aortic aneurysm, mesenteric ischemia, bowel obstruction, retained foreign body, hand and finger lacerations, fractures, and compartment syndrome. Each section focuses primarily on the pitfalls in diagnosis by highlighting the limitations of history, physical examination findings, and diagnostic testing and provides specific risk management strategies.

Acute traumatic compartment syndrome: a systematic review of results of fasciotomy

Issues around diagnosis and treatment of acute compartment syndrome were investigated through a systematic review that examined results of 55 reports of fasciotomy published over four decades and reporting on 1920 fasciotomies. Most were reported since 2000. Injuries below the elbow and knee accounted for at least 75% of cases. The consensus was that diagnosis of compartment syndrome remains primarily based on a high index of suspicion and interpretation of clinical signs and symptoms over high technology methods of diagnosis. Compartment syndrome related amputation occurred in 5.5% of cases and death in 3.3% overall. Compared with fasciotomy before 6 h, delayed fasciotomy beyond 12 h was associated with a lower rate of acceptable outcome (15% for more than 12 h vs. 88% for <6 h), a higher rate of amputation (14% vs. 3.2%) and death (4.3% vs. 2.0%).

Acute limb compartment syndrome: a review

Acute limb compartment syndrome (LCS) is a limb-threatening and occasionally life-threatening condition caused by bleeding or edema in a closed muscle compartment surrounded by fascia and bone, which leads to muscle and nerve ischemia. Well-known causative factors are acute trauma and reperfusion after treatment for acute arterial obstruction. Untreated compartment syndrome usually leads to muscle necrosis, limb amputation, and, if severe, in large compartments, renal failure and death. Alertness, clinical suspicion of the possibility of LCS, and occasionally intracompartmental pressure (ICP) measurement are required to avoid a delay in diagnosis or missed diagnosis. Open fasciotomy, by incising both skin and fascia, is the most reliable method for adequate compartment decompression. The techniques of measuring ICP have advantages and disadvantages, whereas the pressure level that mandates fasciotomy is controversial. Increased awareness of the syndrome and the advent of measurements of ICP pressure have raised the possibility of early diagnosis and treatment. This review reports LCS, including etiology, pathophysiology, diagnosis, ICP measurement, management, and outcome.

Evaluation and management of the high-risk orthopedic emergency

Orthopedic injuries are frequently seen in the ED. Whereas the diagnosis and management of most of these injuries is straightforward, there are distinct pitfalls to avoid. The common theme among the high-risk "pitfall" injuries discussed in this article, besides a thorough patient history and careful physical examination with appropriate radiographs, is a high suspicion for the presence of these injuries. When the EP is knowledgeable about these orthopedic pitfalls, these injuries are much less likely to slip by in clinical practice.

The effect of externally applied subatmospheric pressure on serum myoglobin levels after a prolonged crush/ischemia injury

BACKGROUND

Patients with injuries that cause significant muscle death often develop rhabdomyolysis. The subsequent release and entry of myoglobin into the systemic circulation leads to myoglobinuria, renal injury, and potentially acute renal failure.

METHODS

Large (5 kg) adult rabbits (n = 8) were anesthetized and a 15-kg weight placed on the posterior compartment for 4 hours. After this time, the weight was removed and releasing incisions were made. Subatmospheric pressure (125 mm Hg) was continuously applied to the wounds of four rabbits. Systemic serum samples were obtained at the time of weight removal and at 2, 4, and 8 hours postremoval, and were analyzed for myoglobin content.

RESULTS

Serum myoglobin levels were similar for both groups at the time of weight removal. Serum myoglobin levels demonstrated a progressive increase with time in nontreated animals, and were significantly elevated compared with subatmospheric pressure-treated animals at all time points (p < 0.001).

CONCLUSION

This study shows that application of subatmospheric pressure to an affected body part is associated with lower serum myoglobin levels.

The impact of lower leg compartment syndrome on health related quality of life

Although the aetiology, pathophysiology and treatment of acute compartment syndrome have been well described in the literature, there is limited information on the long-term impact of compartment syndrome on quality of life. We reviewed the medical records and radiographs of all the patients treated with surgical decompression of compartment syndrome. Between 1993 and 1998, 42 cases were identified. There were 30 cases of tibial compartment syndrome and 12 cases involving other limbs. These 30 patients were recalled for a follow-up assessment during which they were asked to complete an EQ-5D (EuroQol), a standardised measure of health related quality of life based on five dimensions (self-care, pain/discomfort, mobility, usual activities and anxiety/depression). Patients were compared with EQ-5D age/sex norms derived from a randomly selected group of patients that had sustained isolated closed tibial shaft fractures. The minimum follow-up time was 12 months. Patients who stated that the appearance of the surgical site was a problem, reported significantly poorer health related quality of life than did patients who had no problem with the appearance. Patients with skin graft reported more problems with pain and discomfort than patients without skin graft. Patients with faster closure times of the wound showed significantly better self-rated health status than patients in whom the wound closure time was longer. Although the patients in this study reported significantly more problems on the dimensions of EQ-5D than were reported in the control group, their overall self-rated health was not statistically different. This study has demonstrated that compartment syndrome may be associated with long-term impact on health related quality of life.

Orthopedic pitfalls in the ED: acute compartment syndrome

Acute compartment syndrome is a rare but potentially disastrous complication of orthopedic injury to the extremities. Compartment syndrome occurs when the circulation and function of muscle within a closed fascial space are compromised by increased pressure within that space. Early diagnosis and treatment is crucial to prevent the devastating complications of this condition. This review article examines the clinical presentation, diagnostic techniques, and management options applicable to the emergency practitioner.

Hyperbaric medicine in soft tissue trauma

Severe crush injuries of the soft tissues can result in tears of the large vessels and destruction of the microcirculation. This produces ischaemia and tissue necrosis and contributes to the development of oedema and compartment syndromes. All these factors compromise tissue survival. Immediately following a crush injury some areas of tissue are obviously irreversibly damaged, and others undamaged. It is common to have a ‘grey area’ between these, where there is uncertainty as to what will survive. Management of crush injury must involve surgical repair of vessels and soft tissues, debridement of obviously dead tissue, and bone stabilization. At the same time tissue perfusion must be maintained by manoeuvres such as fluid replacement and diminution of oedema, and when necessary fasciotomy. It has been proposed that hyperbaric oxygen therapy has a role, as an adjunct, in the maintenance of tissue oxygenation under these conditions, and will improve survival of tissues in the grey area, and thus minimize tissue loss. Hyperbaric oxygen therapy involves breathing 100% oxygen at pressures greater than one atmosphere. Presently, the pressures most often used are in the range 2-3 atmospheres absolute.

Is compartment pressure related to plasma colloid osmotic pressure, in patients during and after cardiac surgery?

Haemodilution is always considerable during cardiopulmonary bypass (CPB). If this extra fluid sits in the muscle compartments then a corresponding rise in the compartment pressure (CP) is to be expected. The aim of this study was to measure pressure changes in a body compartment with new equipment, the MTC (Microtransducer). Changes in plasma colloid osmotic pressure (COP) were also measured during and after CPB to find a connection, if any, between CP and plasma COP. Ten elective consecutive CPB patients were studied. A 3-French (3-F) catheter-size electronic MTC was inserted in an anterior tibial compartment before CPB. The CP was monitored for 48 h. Plasma COP was also measured before, during and after CPB. CP increased significantly during and after CPB in all patients (p=0.01). COP decreased significantly in all patients (p=0.005), but no correlation was found between changes in COP and CP values in this study. Most of the patients reached their highest CP just after weaning off bypass. The CP remained elevated for 48 h, even though it then tended to decrease again. None of the patients reached the starting value within 48 h. COP decreased rapidly after going on bypass, but returned towards its starting value approximately 6 h after bypass. It is concluded that CP increases considerably during and after CPB and stays increased for at least 2 days after CPB. COP decreases during CPB, but reaches normal values 6 h after the CPB. No correlation was found between changes in CP and COP The MTC is a safe and easy way to measure intracompartment pressure.

A simpler, less expensive technique for delayed primary closure of fasciotomies

A variety of techniques have recently been advanced for delayed primary closure of wounds following emergent fasciotomy for compartment syndrome. We introduce a very simple, effective method for gradual reapproximation of margins using daily reapplication of Steri-strips (3M Surgical Products, St. Paul, Minnesota). This method allows final closure of fasciotomy wounds with simple suture in 5-8 days without scar contractures, marginal necrosis, infection, or significant pain. Moreover, because it requires no specialized equipment and can be applied in skilled nursing centers or at home by trained nurses, this technique could reduce the cost of caring for fasciotomy patients.

Magnetic resonance imaging detection of vascular occlusion of a pedicled muscle flap

Contrast-enhanced magnetic resonance imaging (MRI) can be a highly sensitive monitor of tissue blood perfusion. This technique has been used to assess blood flow through liver, kidney, and certain tumors, but has not been widely applied to the study of skeletal muscle circulation. In our study, we used a novel scanning software to obtain contrast-enhanced T2*-weighted gradient echo MRI images of pedicled quadriceps muscle flaps in rabbits in order to study images of arterial, venous, and arterio-venous occlusion. We administered an intravenous bolus of gadoteridol contrast agent at the initiation of scanning, which produces a decrease in T2*-signal and improves the sensitivity of measuring blood perfusion. Within 30 seconds of MRI scanning, control flaps with intact pedicles exhibited a rapid decrease in T2*-signal intensity, indicating adequate perfusion of blood through muscle tissue; however, occluded pedicled flaps showed no significant change in signal intensity, indicating lack of blood perfusion. Differences in signal intensities as measured by MRI between occluded and control flaps were statistically significant (P < 0.05). Selective vascular occlusion of either artery alone, or both artery and vein were detected within 15 minutes, whereas selective venous occlusion could be detected after 2 hours. We conclude that MRI has the ability to assess skeletal muscle perfusion, and is capable of noninvasively evaluating a cross-section of tissue in both superficial and buried flaps. MRI, therefore, may have the potential for evaluating perfusion in muscle flaps (including buried flaps), and other disorders of muscle circulation such as compartment syndrome.

Environmental injuries

Environmental injuries and illnesses can happen in home, work, or recreational settings. The variety and severity of these injuries might require the clinician to call on skills from internal medicine, emergency medicine, and toxicology. Diseases of thermoregulation are hypothermia and hyperthermia. In each instance, treatment is based on the need to restore the patient's core temperature to normal and on monitoring for complications. The victim of a fire might suffer inhalation injury in addition to burns, and it is more likely that the inhalation injury will be fatal. Oxygen deprivation and inhalation of irritant or asphyxiant chemicals contribute to injury. Toxic plants can be the source of poisoning emergencies, especially in children. Misinformation and myths that surround common plants can create diagnostic problems (i.e., which plants really are toxic and require emergency measures). Venomous marine organisms can cause a wide range of injury, from cutaneous eruption to fatal envenomation. Most are encountered in a recreational setting, such as water sports, but keepers of home aquariums are subject to stings from venomous fish. Lightning injury can present many diagnostic and treatment dilemmas. An important point in this regard is that lightning injury and high-voltage electrical injury are different in pathology and require different approaches for treatment. A discussion of electrical, chemical, and thermal burns makes such differences apparent.

The effects of simulated Bier block IVRA on intracompartmental tissue pressure

BACKGROUND

Intravenous regional anesthesia (IVRA) is a useful anesthetic method for closed reduction of fractures. However, IVRA has been associated with an increased incidence of compartment syndrome when treating tibial shaft fractures. The purpose of this study was to measure changes in anterior leg compartment pressures during simulated IVRA.

METHODS

A volunteer study was performed. An indwelling catheter placed in a consistent location between subjects was used to measure tissue pressure. A vinyl leg splint was used for exsanguination followed by thigh tourniquet inflation (300 mmHg). Normal saline (1.5 mL/kg) was injected through the greater saphenous vein (1.0 mL/s). Pressure measurements were obtained before and after tourniquet inflation, at 10 mL increments during saline injection, and intermittently after volume injection with the tourniquet inflated, then deflated.

RESULTS

There was no significant difference in tissue pressure before (2.4 +/- 2.2 mmHg) and after (4.3 +/- 3.7 mmHg) tourniquet inflation (P = 0.11). No significant difference in tissue pressure were found as a function of injected volume (P = 0.62), as a function of time following saline injection during tourniquet inflation (P = 0.08), and after tourniquet deflation (P = 0.16).

CONCLUSIONS

We conclude that in the normal atraumatic limb, simulated IVRA using normal saline does not increase tissue pressure within the anterior leg compartment.

A simple device for closure of fasciotomy wounds

Early decompressive fasciotomy is essential in the prevention of the sequelae of compartment syndrome. Many techniques have been described for the closure of the fasciotomy wound, and controversy exists as to which method is the best. Primary closure is often impossible secondary to tissue retraction and edema. Split-thickness skin grafting leaves a thin, insensate, and often aesthetically unpleasing result. Gradual mechanical dermal apposition has been used with increasing frequency, and has been shown to be effective in the closure of fasciotomies, but often takes 7-10 days for closure. We present our experience with the STAR, a mechanical method of fasciotomy wound closure that is effective in 2-4 days, and is extremely simple to use.