Intraoperative acute lower extremity ischemia detected by near-infrared spectroscopy

Recommendations for haemodynamic and neurological monitoring in repair of acute type a aortic dissection

During treatment of acute type A aortic dissection there is potential for both pre- and intra-operative malperfusion. There are a number of monitoring strategies that may allow for earlier detection of potentially catastrophic malperfusion (particularly cerebral malperfusion) phenomena available for the anaesthetist and surgeon. This review article sets out to discuss the benefits of the current standard monitoring techniques available as well as desirable/experimental techniques which may serve as adjuncts in the monitoring of these complex patients.

Near-infrared spectroscopy to monitor peripheral blood flow perfusion

BACKGROUND

Non-invasive evaluation of peripheral perfusion may be useful in many contexts including peri-operative monitoring. We validated a novel non-invasive spectroscopy technique to assess peripheral perfusion. This method, which is based on the measurement of tissue saturation variations after an ischemic period, was compared to strain gauge plethysmography and radionuclide plethysmography. The technique uses near-infrared spectroscopy (NIRS) to determine the rate of change of forearm tissue saturation during reactive hyperemia.

METHODS

In a prospective crossover study, 25 subjects were simultaneously evaluated with NIRS and strain gauge plethysmography. Six baseline flow measurements were performed to assess the reproducibility of each method. Twenty-seven serial measurements were then made to evaluate flow variation during forearm reactive hyperemia.

RESULTS

Strain gauge and NIRS methods showed excellent reproducibility with intra-class correlation coefficients of 0.96 and 0.93, respectively.

CONCLUSION

The NIRS technique appears well suited for the non-invasive evaluation of limb perfusion.

Near-infrared spectroscopy identifies compartment syndrome in an infant

Acute compartment syndrome is a surgical emergency requiring immediate intervention to limit tissue and nerve injury. Although the measurement of compartment pressure is frequently performed, there is controversy regarding the pressure at which fasciotomy should be performed. Near-infrared spectroscopy (NIRS) uses the same technology as pulse oximetry to estimate tissue oxygenation. To date, NIRS is used most commonly to estimate cerebral oxygenation during intraoperative anesthetic care. The authors present a 1-month-old infant who developed an acute compartment syndrome of the right lower extremity after cardiac surgery. In addition to the measurement of compartment pressures, the diagnosis of compartment syndrome was confirmed by NIRS with a value of 15% in the involved leg versus 40% to 50% in the noninvolved contralateral lower extremity. The potential use of this modality in identifying compartment syndrome is reviewed.