Table 2.
Summary of the evidence on NIRS-derived autoregulation in TBI.
| Author, Year | N (m:f) | Device (Type) | Output | Control | Conclusion |
|---|---|---|---|---|---|
| (Adelson et al., 1998) [86] | 10 (6:4) | INV03100A, Medtronic, MN, USA and NIRO500, Hamamatsu Photonics, Hamamatsu, Japan. (SRS and CW respectively; S-D NR) |
THb, HbO2, Hb, and rSO2 | CPP, MAP, ICP and PaCO2 |
High ICP and decreased CPP correlated with increased THb and HbO2 indicating raised CBV and hyperemia. MAP was not associative. NIRS positively predicted cerebral oxygen desaturations with hyperventilation. |
| (Dunham et al., 2002) [92] | 4 (3:1) | INVOS 4100, Medtronic, MN, USA. (SRS; S-D NR) |
rSO2 | CPP, MAP, ICP | Cerebral oximetry correlated significantly with CPP. As such, it could be an adjunct to CPP management. |
| (Zweifel et al., 2010) [93] | 40 (31:9) | NIRO 200, Hamamatsu Photonics U.K. Ltd., Hertfordshire, UK. (SRS; S-D NR) |
THx | PRx | THx showed a significant correlation with the validated volume reactivity index PRx. |
| (Shafer et al., 2010) [94] | 22 (10:12) | INVOS 5100, Medtronic, MN, USA. (CW; S-D NR) |
rSO2 | XeCT | The relationship between either the left or right NIRS values and Xe/CT scan was not significant. |
| (Diedler et al., 2011) [95] | 37 (NR) | NIRO 200, Hamamatsu Photonics U.K. Ltd., Hertfordshire, UK. (SRS; S-D NR) |
THx | PRx | The agreement between PRx and THx is a function of the power of slow oscillations in the input signals. |
| (Taussky et al., 2012) [96] | 8 (2:6) | Bifrontal NIRS optodes, Casmed, Branford, CT, USA. (CW; S-D 4.5 cm) |
rSO2 | CBF | CT perfusion CBF has a significant linear correlation with NIRS derived rSO2. |
| (Kim et al., 2014) [97] | 10 (7:3) | Inhouse, DCS and NIRS system, Noncommercial. (SRS; S-D 2.5 cm) |
CBF, ΔHbO2, ΔHb and ΔTHb in 10 TBI patients | CBF, ΔHbO2, ΔHb and THb in 10 healthy controls | HbO2, Hb, and THb concentration increased significantly in the brain-injured cohort with head-of-bed lowering. Accordingly, DCS/NIRS hybrid device is well-suited to provide non- invasive, continuous hemodynamic monitoring. |
| (Highton et al., 2015) [98] | 27 (13:14) | NIRO 100, Hamamatsu Photonics U.K. Ltd., Hertfordshire, UK. (SRS; S-D 4 cm) |
THx, TOx | PRx, Mx | Significant agreement among PRx and THx, and between Mx and TOx. However, the strength of the interrelationship between ICP or TCD and NIRS signals, THI or rSo2, limits the degree of agreement between these reactivity indices. |
| (Bindra et al., 2015) [99] | 19 (12:7) | ForeSight, Casmed, Connecticut, USA. (CW; S-D NR) |
nTOx | iTOx | nTOx from Finometer photoplethysmography and NIRS gives a similar measurement of cerebrovascular autoregulation to iTOx. |
Abbreviations: regional tissue oxygen saturation (rSO2), oxyhemoglobin concentration (HbO2), total hemoglobin concentration (THb), deoxyhemoglobin concentration (Hb), concentration change (Δ), cerebral perfusion pressure (CPP), intracranial pressure (ICP), cerebral blood flow (CBF), partial pressures of arterial carbon dioxide (PaCO2), xenon-enhanced computed tomography (XeCT), mean arterial pressure (MAP), pressure reactivity index (PRx), total hemoglobin reactivity index (THx), tissue oxygen reactivity index (TOx), mean velocity index (Mx), noninvasive tissue oxygen reactivity index (nTOx), invasive tissue oxygen reactivity index (iTOx), near-infrared spectroscopy (NIRS), continuous wave modified Beer–Lambert law (CW), spatially resolved spectroscopy (SRS), source detector distance (S-D), not reported (NR).