Military and AAOS Collaboration Yields New CPG on Acute Compartment Syndrome

During its December 2018 meeting, the AAOS Board of Directors approved a clinical practice guideline (CPG) on Management of Acute Compartment Syndrome (ACS). The CPG is the first of a series of planned guidelines funded by the Department of Defense (DoD) and created by a collaborative effort of military and civilian surgeon members of the Major Extremity Trauma and Rehabilitation Consortium (METRC) and Academy research staff.

“A particular challenge in constructing this particular CPG is the fact that there are no standard diagnostic criteria for ACS,” the guideline development group noted in its introduction to the CPG document. “Clinicians diagnose compartment syndrome using their clinical judgment and/or results of objective measurements (such as compartment pressure), and once the diagnosis is made, emergent fasciotomy is nearly always performed (Fig. 1).


Fig. 1 Surgical release of a compartment (fasciotomy) in a patient with a dislocated knee. An external fixator is used to stabilize the knee; the open wound shows the surgical release of the compartments.
Reproduced from Schenck RC, Hunter RE, Ostrum RF, et al: Knee dislocations. Instr Course Lect 1999;48:519.

The literature does not offer a wealth of strong scientific evidence supporting any specific method for the diagnosis and treatment of compartment syndrome. This is reflected by the recommendations offered in the CPG, which the reader will note are not fully backed by the highest possible level of evidence (Strong: comprising evidence from two or more high-quality studies with consistent findings for recommending for or against the intervention). Nonetheless, as with other CPGs covering orthopaedic conditions for which numerous randomized, controlled trials are not available, the workgroup for this guideline distilled the existing evidence that is available in order to offer useful guidance for clinicians encountering suspected or confirmed ACS.

Among the 15 recommendations, three are backed by the second highest, or Moderate, level of evidence—defined as evidence from two or more moderate-quality studies with consistent findings, or evidence from a single high-quality study for recommending for or against the intervention—as follows:

  1. Under serum biomarkers, in patients with acute vascular ischemia, femoral vein lactate concentration sampled during surgical embolectomy may assist in the diagnosis of ACS.
  2. Under pressure methods, intracompartmental pressure monitoring assists in diagnosing ACS.
  3. Under pressure methods, there is moderate evidence supporting the use of repeated/continuous intracompartmental pressure monitoring and a threshold of diastolic blood pressure minus intracompartmental pressure > 30 mmHg to assist in ruling out ACS.

Four other recommendations are offered with support from evidence characterized as Limited—including that serial clinical examination findings can help rule out ACS and that negative pressure wound therapy for management of fasciotomy wounds may be effective in reducing time to wound closure and need for skin grafting. The remaining entries are classified as Consensus, meaning the CPG group is making a recommendation based on its members’ clinical opinion.

Weighing the evidence

Andrew Schmidt, MD, representing the Orthopaedic Trauma Association and serving as co-chair of the guideline development group—along with Col. Patrick Osborn, MD, representing the Society of Military Orthopaedic Surgeons—commented: “A rigorous review of the literature demonstrates a dearth of evidence and consensus regarding specific criteria for the precise diagnosis of ACS. Thus, the CPG stresses the importance of vigilance and a high index of suspicion for those treating patients at risk for ACS. The CPG group agreed that if ACS is diagnosed or suspected, prompt, complete release of the affected compartment(s) is warranted.”

Dr. Schmidt noted that “the guidelines emphasize that both the clinical examination (Limited evidence) and either repeated or continuous compartment pressure measurement (Moderate evidence) play a role in the early diagnosis of ACS.” In the matter of diagnosis, the CPG notes that evidence classified as Limited supports the effectiveness of a reliable physical examination, and evidence characterized as Moderate indicates that continuous or repeated compartment pressure measurements assist in the diagnosis of ACS when using a perfusion pressure of < 30 mmHg. Yet, Dr. Schmidt noted, no specific recommendations are made for a particular compartment measurement method.

Laboratory biomarkers, he said, “remain unproven in discerning ACS from other causes of muscle injury.” When a clinician is faced with late presentation of ACS, the CPG development group agreed that neither laboratory biomarkers nor pressure measurements provide reliable guidance on deciding to perform fasciotomy. In fact, Dr. Schmidt noted, “the CPG group does not recommend performing fasciotomy when there is evidence of irreversible muscle and nerve damage in the extremity.”

Practical guidance

Advances continue to be made in the understanding and management of ACS, and many innovations in technique and technology for treating this potentially devastating complication have been made in the military setting. As in other spheres of orthopaedics, available evidence may trail what is being put to successful use in practice.

“Many promising and/or alternative diagnostic modalities, such as near-infrared spectroscopy or direct oxygen measurement, currently do not have evidence supporting their use, and there are no guidelines regarding diagnosis and management of late-presenting or missed ACS,” Dr. Schmidt said. “The consensus opinions developed by the panel represent what is currently done by expert orthopaedic traumatologists, which can serve as a reasonable basis for clinical practice until the time comes when a more evidence-based approach to these questions is possible.”

Thus, clinicians who encounter suspected ACS in their practices may benefit from considering this CPG in its entirety. Overall, Dr.
Schmidt said, the CPG stresses the importance of vigilance and a high index of suspicion for those treating patients at risk for ACS.

The development group noted that although this CPG was developed in a collaboration with military surgeons and the DoD, it is designed to address ACS in all settings; however, it may be particularly important for military applications.

“As we are in the longest period of continuous warfare in U.S. history, topics germane to Tactical Combat Casualty Care remain a primary concern in military medicine,” the group wrote. “The survival rate of extremity injured casualties is associated with two Joint Trauma System interventions: educational programs on tourniquet usage and fasciotomy education prior to deployment. As combat trauma is typically composed of the mechanisms of injury associated with ACS but in an austere, remote environment, evidence-based guidelines for the rapid treatment and comprehensive management of ACS are vital.”

The DoD/METRC CPG on ACS, and other Academy-approved CPGs, may be accessed at www.orthoguidelines.org/guidelines, or via the Ortho Guidelines app.

Terry Stanton is the senior science writer for AAOS Now.

Advertisements


Advertisement