Relationship between Near Infrared Spectroscopy and Intra-compartmental Pressures

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.

Diagnostic Modalities for Acute Compartment Syndrome of the Extremities: A Systematic Review

Importance

Acute compartment syndrome (ACS) can cause catastrophic tissue damage leading to permanent muscle and nerve loss. Acute compartment syndrome is a clinical diagnosis, with intracompartmental pressure (ICP) used in equivocal cases. There are no reliable diagnostic methods. The clinical evaluation is impossible to standardize, and the threshold for ICP has been known to be unreliable; thus, guidelines for diagnosis can result in overtreatment or delayed diagnosis.

Objective

To present and review the advantages and disadvantages of each diagnostic modality and identify gaps that need to be addressed in the future and to review the most used and appropriate animal and human ACS models.

Evidence Review

We included clinical studies and animal models investigating diagnostic modalities for ACS of the extremities. A MEDLINE and Web of Science search was performed. The protocol for the study was registered on PROSPERO (CRD42017079266). We assessed the quality of the clinical studies with Newcastle-Ottawa scale and reported level of evidence for each article.

Findings

Fifty-one articles were included in this study, reporting on 38 noninvasive and 35 invasive modalities. Near-infrared spectroscopy and direct ICP measurement using a Stryker device were the most common, respectively. Cadaveric studies used saline infusions to create an ACS model. Most studies with human participants included injured patients with acquired ACS or at risk of developing ACS. In healthy human participants, tourniquets formed the most commonly used ACS model. Application of tourniquets and infusion of saline or albumin were the most used ACS models among animal studies.

Conclusions and Relevance

This article reports on the most common as well as many new and modified diagnostic modalities, which can serve as inspiration for future investigations to develop more effective and efficient diagnostic techniques for ACS. Future studies on diagnostic modalities should include the development of tools for continuous assessment of ICP to better identify the earliest alterations suggestive of impending ACS. With the advent of such technologies, it may be possible to develop far less aggressive and more effective approaches for early detection of ACS.

Noninvasive diagnostics for extremity compartment syndrome following traumatic injury: A state-of-the-art review

Acute compartment syndrome (ACS) is a serious medical condition that can occur following traumatic injury to an extremity. If left undiagnosed, ACS can eventuate in amputation of the limb or even death. Because of this, fasciotomy to release the pressure within the muscle and restore tissue perfusion is often performed upon suspicion of ACS, as the sequelae to fasciotomy are less severe than those associated with not performing the fasciotomy. Currently, the "gold standard" of diagnosis is based on clinical assessment of such symptoms as pain out of proportion to the injury, obvious high pressure and swelling, pain on passive stretch of the muscles in the affected compartment, and deficits in sensory and/ormotor functions. Diagnosis is often confirmed using invasive measurements of intramuscular pressure (IMP); however, controversy exists as to how direct IMP measurement should be accomplished and threshold pressures for accurate diagnosis. Because of this and the attendant issues with invasive measurements, investigators have been searching over the last 25 years for a noninvasive means to quantitatively measure IMP or perfusion to the limb. The purpose of this review is to summarize the current state of the art of noninvasive devices that could potentially be used to diagnose ACS accurately and objectively. To do this, we divide the discussion into those medical devices that primarily measure mechanical surrogates of IMP (e.g., tissue hardness or myofascial displacement) and those that primarily measure indices of tissue perfusion (e.g., tissue oxygen saturation via near-infraredspectroscopy). While near-infrared spectroscopy-basedtechnologies have shown the most promise, whether such technologies will be of diagnostic benefit await the completion of ongoing clinical trials. LEVEL OF EVIDENCE: Systematic Review, level II.

Lower limb perfusion during robotic-assisted laparoscopic radical prostatectomy evaluated by near-infrared spectroscopy: an observational prospective study

Background

Decreased perfusion in the lower extremities is one of the several adverse effects of placing patients in a lithotomy or Trendelenburg position during surgery. This study aimed to evaluate the effects of patient positioning in lower limb perfusion patients undergoing robotic-assisted laparoscopic radical prostatectomy (RARP) using near-infrared spectroscopy (NIRS).

Methods

This observation study comprised 30 consenting males with American Society of Anaesthesiologists physical status classes I and II (age range, ≥20 to < 80 years). Regional saturation of oxygen measurements was obtained using an INVOS™ oximeter (Somanetics, Troy, MI, USA). A NIRS sensor was positioned on the surface of the skin at the mid-diaphyseal region of the calf muscles (the gastrocnemius and soleus), over the posterior compartment, in the right lower leg. Regional saturation of oxygen (rSO₂) was sampled during the following time points: before and 5 min after induction of anaesthesia (T0,T1); 5 min after establishment of pneumoperitoneum in a 0° lithotomy position (T2); 5 min after a 25° Trendelenburg position (T3); 30, 60, 90 and 120 min after pneumoperitoneum in a Trendelenburg position (T4, T5, T6 and T7, respectively); after desufflation in a supine position (T8); and after tracheal extubation (T9).

Results

Lower limb perfusion evaluated by NIRS was increased after induction of anaesthesia and maintained during steep Trendelenburg positions in RARP patients with no risk for lower limb compartment syndrome (LLCS) (T0:65 ± 7.2%, T1:69 ± 6.1%, T2:70±:6.1%, T3:68 ± 6.7%, T4:66 ± 7.5%, T5:67 ± 6.9%, T6:68 ± 7.2%, T8:73 ± 7.2%, T9:71 ± 7.9%, respectively).

Conclusions

Lower limb perfusion evaluated by NIRS was maintained during the RARP procedure. Correct patient positioning and careful assessment of risk factors such as vascular morbidity could be important for the prevention of LLCS during RARP.

Continual near-infrared spectroscopy monitoring in the injured lower limb and acute compartment syndrome: an FDA-IDE trial

Aims

The aim of this study was to evaluate near-infrared spectroscopy (NIRS) as a continuous, non-invasive monitor for acute compartment syndrome (ACS).

Patients and Methods

NIRS sensors were placed on 86 patients with, and 23 without (controls), severe leg injury. NIRS values were recorded for up to 48 hours. Longitudinal data were analyzed using summary and graphical methods, bivariate comparisons, and multivariable multilevel modelling.

Results

Mean NIRS values in the anterior, lateral, superficial posterior, and deep posterior compartments were between 72% and 78% in injured legs, between 69% and 72% in uninjured legs, and between 71% and 73% in bilaterally uninjured legs. In patients without ACS, the values were typically > 3% higher in injured compartments. All seven limbs with ACS had at least one compartment where NIRS values were 3% or more below a reference uninjured control compartment. Missing data were encountered in many instances.

Conclusion

NIRS oximetry might be used to aid the assessment and management of patients with ACS. Sustained hyperaemia is consistent with the absence of ACS in injured legs. Loss of the hyperaemic differential warrants heightened surveillance. NIRS values in at least one injured compartment(s) were > 3% below the uninjured contralateral compartment(s) in all seven patients with ACS. Additional interventional studies are required to validate the use of NIRS for ACS monitoring. Cite this article: Bone Joint J 2018;100-B:787-97.

Preliminary Experience in Combined Somatic and Cerebral Oximetry Monitoring in Liver Transplantation

OBJECTIVE

The use of cerebral near-infrared spectroscopy (NIRS) has become widespread in cardiac surgery after research demonstrated an association between perioperative cerebral desaturations and postoperative complications. Somatic NIRS desaturation also is associated with an increased risk of postoperative complications and mortality. The objective of this study was to explore the trends of both somatic and cerebral NIRS during liver transplantation.

DESIGN

A prospective, single-site, observational case series.

SETTING

Tertiary care center.

PARTICIPANTS

The study comprised 10 patients undergoing liver transplantation.

INTERVENTIONS

NIRS sensors were placed on the forehead (cerebral regional oxygen saturation [rSO₂]) and on the right arm and right leg (somatic rSO₂) to measure tissue perfusion. Desaturation was defined as a 20% decrease of baseline values for 15 seconds.

MEASUREMENTS AND MAIN RESULTS

In all patients, parallel changes in both cerebral and somatic rSO₂ values were observed during phlebotomy, bleeding, transfusion, portal vein clamping, and the use of vasoactive agents. Induction of anesthesia increased cerebral rSO₂ more than it did somatic values. However, ascites removal, abdominal manipulation, and clamping of the inferior vena cava (IVC) were associated with nonparallel changes in cerebral and somatic rSO₂. Ascites removal was associated with increased somatic leg rSO₂, and IVC clamping and abdominal hypertension were associated with a significant reduction in somatic leg rSO₂. Somatic leg desaturation instead of arm or cerebral desaturation was associated with more postoperative complications.

CONCLUSIONS

The use of combined NIRS monitoring allows for the identification of the source of somatic or cerebral desaturation. Compromised venous flow from the IVC from clamping or abdominal compartment syndrome typically is associated with the appearance of more pronounced leg than arm desaturation.

Compartment Pressures in Children With Normal and Fractured Forearms: A Preliminary Report

INTRODUCTION

Acute compartment syndrome (ACS) can lead to irreversible damage if fasciotomy is not performed in a timely manner. Needle manometry is a tool to confirm suspected ACS. The threshold for compartment pressures that can be tolerated has been debated. The aim of this study is to assess the normal compartment pressures in noninjured forearms of children. Further, we sought to quantify the maximum tolerable compartment pressures in fractured forearms of children, thus establishing a baseline and providing guidance in evidence-based decision making to evaluate children with suspected ACS.

METHODS

This prospective study included children up to the age of 16 years with forearm fractures that needed reduction with or without osteosynthesis. Between June 2009 and March 2013, 41 children were included. Mean age was 9.25 years (range, 4 to 15.4 y). We used needle manometry to measure the pressures in the superficial and deep volar as well as in the dorsal compartments (DCs) on both the forearms. The mean pressures between compartments in healthy versus injured arms were analyzed using a 1-sided, paired t test.

RESULTS

On the injured side, the mean compartment pressure was 19.12 mm Hg (range, 3 to 49 mm Hg) in the deep volar compartment, 15.56 mm Hg (range, 5 to 37 mmHg) in the DC, and 14.8 mm Hg (range, 2 to 35 mm Hg) in the superficial volar compartment. On the noninjured side, the mean compartment pressure was 12.9 mm Hg (range, 6 to 31 mm Hg) in the DC, 10.22 mm Hg (range, 3 to 22 mm Hg) in the deep volar compartment, and 9.66 mm Hg (range, 3 to 21 mm Hg) in the superficial volar compartment. We measured an absolute compartment pressure of >30 mm Hg in 15 patients on the fractured side. Three of them had an absolute compartment pressure of >45 mm Hg. Only 1 had ACS. This patient underwent fasciotomy and was excluded for further analysis. On follow-up (mean, 24.84 mo), no patient was found to have any sequelae of ACS.

DISCUSSION

This is the first study to report normal compartment pressure measurements in noninjured forearms and in fractured forearms without clinical suspicion of ACS in children.The mean compartment pressure measured in the deep volar compartment (DVC) in healthy children was 10.22 mm Hg (range, 3 to 22 mm Hg) and therefore slightly higher than in adults. Some children with fractures tolerated absolute compartment pressures >30 mm Hg without clinical signs of ACS. Fasciotomy in children under close observation could eventually be delayed despite surpassing the accepted pressure limits for adults.

LEVEL OF EVIDENCE

Level I-prognostic.

[Acute extremity compartment syndrome: current concepts in diagnostics and therapy]

Acute compartment syndrome of the upper and lower limbs is observed following trauma, reperfusion or as an intraoperative complication caused by positioning. The pathophysiology of the disorder has been extensively described and is well known as a loss of perfusion due to rising compartmental pressures. It is a serious and potentially limb- and life-threatening complication. Early diagnosis is made primarily based on clinical findings. Early and focused therapy is crucial to prevent the devastating complications of this acute condition. However, diagnosis can be difficult, particularly in unconscious patients. Thus, in uncertain cases, pressure measurements are essential. Dermato-fasciotomy is the routine method to decompress the compartmental space. This review article examines the clinical findings, diagnostic techniques, and management options for the patient with musculoskeletal injuries.

Upper extremity acute compartment syndrome during tissue plasminogen activator therapy for pulmonary embolism in a morbidly obese patient

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Deep vein thrombosis (DVT) and pulmonary embolism (PE) are more frequently observed morbidly obese patients.

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As the use of thrombolytic therapy has become more common in the treatment of myocardial infarction (MI) and PE, acute compartment syndrome (ACS) has been reported as a rare complication of thrombolytic therapy.

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As soon as the diagnosis of compartment syndrome is made, an emergency fasciotomy should be performed.

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Close follow-up is required to avoid wound healing problems after the fasciotomy.

Introduction

Deep vein thrombosis (DVT) and pulmonary embolism (PE) are more frequently observed in morbidly obese patients. Tissue plasminogen activator (tPA) is a thrombolytic agent which dissolves the thrombus more rapidly than conventional heparin therapy and reduces the mortality and morbidity rates associated with PE. Compartment syndrome is a well-known and documented complication of thrombolytic treatment. In awake, oriented and cooperative patients, the diagnosis of compartment syndrome is made based on clinical findings including swelling, tautness, irrational and continuous pain, altered sensation, and severe pain due to passive stretching. These clinical findings may not be able to be adequately assessed in unconscious patients.

Presentation of case

In this case report, we present compartment syndrome observed, for which fasciotomy was performed on the upper right extremity of a 46-year old morbidly obese, conscious female patient who was receiving tPA due to a massive pulmonary embolism.

Discussion

Compartment syndrome had occurred due to the damage caused by the repeated unsuccessful catheterisation attempts to the brachial artery and the accompanying tPA treatment. Thus, the bleeding that occurred in the volar compartment of the forearm and the anterior compartment of the arm led to acute compartment syndrome (ACS). After relaxation was brought about in the volar compartment of the forearm and the anterior compartment of the arm, the circulation in the limb was restored.

Conclusion

As soon as the diagnosis of compartment syndrome is made, an emergency fasciotomy should be performed. Close follow-up is required to avoid wound healing problems after the fasciotomy.