Rockwood, Green, and Wilkins' Fractures, 10e Package

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CHAPTER 6 • Compartment Syndrome in Children

regional anesthesia with complete motor and sensory blockade masked nociceptive pain, not ischemic pain, and therefore does not affect compartment syndrome evaluation. 16 Despite this, there is currently not a strong recommendation for or against the use of regional anesthesia or patient-controlled analgesia in chil dren when there is a concern for development of compartment syndrome. 9 The American and European Society on Regional Anesthesia have established guidelines for dosing of periph eral nerve blocks in children to reduce variability in practice. 43 Further data are needed in this area. In the case of “silent compartment syndrome,” there is an absence of pain. 1,26 Agitation and anxiety may be present instead. Pressure , swelling, and tenseness of the affected com partment may be objective but often unreliable findings of early compartment syndrome. 26,38 Paralysis is a late and insensitive finding of compartment syndrome. One retrospective study at a pediatric tertiary care center reviewed 10 years of data and identified five cases of silent compartment syndrome. 17 Three were associated with upper extremity fractures and two with lower extremity fractures. At the time of diagnosis, silent com partment syndrome patients demonstrated no pulselessness, no pain with range of motion (ROM), no anxiety, and all had com pressible compartments. Four out of five had paralysis. This atypical presentation may be due to sensory deficits. 17 In unclear clinical presentations, compartment pressure measurements are recommended. In the pediatric setting, com partment pressures are best measured under conscious seda tion or anesthesia. Multiple measurements at different sites and depths within each compartment are recommended. Compart ment pressure measurements close to the level of fracture may be most accurate. Historically, the threshold for lower leg fasciotomies in both adults and children was an absolute pressure greater than 30 mm Hg or pressures within 30 mm Hg of either the diastolic blood pressure or the mean arterial pressure. Application of this threshold to children may not be appropriate. Baseline com partment pressures have been shown to be higher in children compared to adults: normal adult leg compartment pressures are between 5.2 and 9.7 mm Hg, whereas in children they are 13.3 to 16.6 mm Hg. 41 Also, children have been shown to tol erate compartment pressures above traditional thresholds for fasciotomies, and many do not develop compartment syndrome without surgical treatment. A prospective study identified 41 children with fractured forearms. Of these patients, 15 had nee dle manometry compartment pressure readings above 30 mm Hg in the injured extremity. Only 1 in 15 went on to develop compartment syndrome. All the remaining children tolerated pressures greater than 30 mm Hg without developing com partment syndrome. Authors argue that traditional surgical cutoff pressure measurements may not apply to children and that children may be closely observed and may ultimately avoid the need for fasciotomies. 44 We recommend serial evaluation of the at-risk extremity and decompressive fasciotomy when there are clinical signs of compartment syndrome development and elevated compartment pressure readings. The 2020 Amer ican Academy of Orthopaedic Surgery Clinical Practice Guide line on Management of Acute Compartment Syndrome noted

TABLE 6-1. Causes of Compartment Syndrome

Intrinsic

Extrinsic

Fracture

Compressive casts, dressings

Soft tissue trauma without fracture Pneumatic antishock garments

Vascular injury

Penetrating trauma

Burns

Burn eschar

Animal + insect bites Fluid infusion secondary to intravenous (or intraosseous) extravasation (also arthroscopy)

Bleeding disorders

Reperfusion injury following prolonged ischemia

Elective orthopaedic procedure— osteotomy

syndrome, the FDA recommended validation with further inter ventional studies. 39 The diagnosis of compartment syndrome is challenging and can be more difficult in children, and particularly in infants. In addition, a high index of suspicion must be main tained in obtunded or sedated patients. The six Ps— pain, pressure, pallor, paresthesia, paralysis, and pulselessness— have been described as clinical markers of com partment syndrome. The reliability of these clinical findings is questionable, however, as they may be difficult to obtain in the pediatric or obtunded patient or in a patient with delayed presentation in whom irreversible tissue damage has already occurred. In younger children, the three As are more useful in making a diagnosis of compartment syndrome, and they are anxiety (or restlessness), agitation (or crying), and an increasing analgesia requirement. 2,6 Pain out of proportion to the injury, especially aggravated by passive motion of the compartment, is a sensitive and early physical finding of compartment syndrome. 26 An increasing analgesia requirement, both in dose and frequency, is also a helpful early marker in children. 2 A retrospective review of 21 pediatric compartment syndrome patients demonstrated that swelling and worsening pain were presenting signs in 100% of cases and paresthesias were seen in 75%. 19 A systematic review investigating if regional anesthesia or patient-controlled analgesia masked the pain of compartment syndrome in children reported mixed results, with 75% of studies after 2009 demonstrating that regional anesthesia and patient-controlled analgesia can safely be used in children with out masking compartment syndrome. Authors postulate that modernized ultrasound-guided techniques for regional blocks allow for better targeting and thus lower volumes of injected anesthetic into a given compartment. Authors also argue that