Using the relationship between brain tissue regional saturation of oxygen and mean arterial pressure to determine the optimal mean arterial pressure in patients following cardiac arrest: A pilot proof-of-concept study

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• 作者：Mypinder S. Sekhon^a ; Peter Smielewski^b ; Tahara D. Bhate^a ; Penelope M. Brasher^c ; Denise Foster^a ; David K. Menon^b ; Arun K. Gupta^b ; Marek Czosnyka^d ; William R. Henderson^a ; Kenneth Gin^e ; Graham Wong^e ; Donald E. Griesdale^a ; ^c ; ^f ; ^{donald.griesdale@vch.ca" class="auth_mail" title="E-mail the corresponding author}
• 关键词：AHA ; American Heart Association ; CCU ; coronary care unit ; COx ; correlational coefficient between MAP and rSO2 ; CPP ; cerebral perfusion pressure ; FVd/FVm ; flow velocity diastolic/mean ; HIBI ; hypoxemic ischemic brain injury ; ICP ; intracranial pressure ; ICU ; intensive care unit ; IQR ; interquartile range ; MAP ; mean arterial pressure ; MAPOPT ; optimal mean arterial pressure ; ONSD ; optic nerve sheath diameter ; ROSC ; return of spontaneous circulation ; rSO2 ; regional saturation of oxygen ; SD ; standard de
• 刊名：Resuscitation
• 出版年：2016
• 出版时间：September 2016
• 年：2016
• 卷：106
• 期：Complete
• 页码：120-125
• 全文大小：1017 K

文摘

Prospectively assess cerebral autoregulation and optimal mean arterial pressure (MAP_OPT) using the dynamic relationship between MAP and regional saturation of oxygen (rSO₂) using near-infrared spectroscopy.

Methods

Feasibility study of twenty patients admitted to the intensive care unit following a cardiac arrest. All patients underwent continuous rSO₂ monitoring using the INVOS^® cerebral oximeter. ICM+^® brain monitoring software calculates the cerebral oximetry index (COx) in real-time which is a moving Pearson correlation coefficient between 30 consecutive, 10-s averaged values of MAP and correspond rSO₂ signals. When rSO₂ increases with increasing MAP (COx ≥0.3), cerebral autoregulation is dysfunctional. Conversely, when rSO₂ remains constant or decreases with increasing MAP (COx <0.3), autoregulation is preserved. ICM+^® fits a U-shaped curve through the COx values plotted vs. MAP. The MAP_OPT is nadir of this curve.

Results

The median age was 59 years (IQR 54–67) and 7 of 20 were female. The cardiac arrest was caused by myocardial infarction in 12 (60%) patients. Nineteen arrests were witnessed and return of spontaneous circulation occurred in a median of 15.5 min (IQR 8–33). Patients underwent a median of 30 h (IQR 23–46) of monitoring. COx curves and MAP_OPT were generated in all patients. The mean overall MAP and MAP_OPT were 76 mmHg (SD 10) and 76 mmHg (SD 7), respectively. MAP was outside of 5 mmHg from MAP_OPT in 50% (SD 15) of the time. Out of the 7672 5-min averaged COx measurements, 1182 (15%) were at 0.3 or above, indicating absence of autoregulation. Multivariable polynomial fractional regression demonstrated an increase in COx with increasing temperature (P = 0.008).

Conclusions

We demonstrated the feasibility to determine a MAP_OPT using cerebral oximetry in patients after cardiac arrest.