Statistical cerebrovascular reactivity signal properties after secondary decompressive craniectomy in traumatic brain injury : A CENTER-TBI pilot analysis

• Decompressive craniectomy (DC) in traumatic brain injury (TBI) has been suggested to influence cerebrovascular reactivity. We aimed to determine if the statistical properties of vascular reactivity metrics and slow-wave relationships were impacted after DC, as such information would allow us to comment on whether vascular reactivity monitoring remains reliable after craniectomy. Using the CENTER-TBI high-resolution intensive care unit (ICU) cohort, we selected those secondary DC patients with high-frequency physiologic data for both: at least 24 hours before DC, and more than 48 hours post-DC. Data for all physiology measures was separated into: the 24 hours before DC, the first 48 hours post DC, and beyond 48 hours post-DC. We produced slow-wave data sheets for intra-cranial pressure (ICP) and mean arterial pressure (MAP) per patient. We also derived pressure reactivity index (PRx) as continuous cerebrovascular reactivity metrics updated every minute. The time-series behavior of PRx was modeled for each time period per patient. Finally, the relationship between ICP and MAP during these 3 time periods was assessed using time-series vector autoregressive integrative moving average (VARIMA) models, impulse response function (IRF) plots, and Granger causality testing. Ten patients were included in this study. Mean PRx and proportion of time above PRx thresholds were not affected by craniectomy. Similarly, PRx time-series structure was not affected by DC, when assessed in each individual patient. This was confirmed with Granger causality testing, and VARIMA IRF plotting for the MAP/ICP slow-wave relationship. PRx metrics and statistical time-series behavior appears not to be substantially influenced by DC. Similarly, there is little change in the relationship between slow-waves of ICP and MAP before and after DC. This may suggest that cerebrovascular reactivity monitoring in the setting of DC may still provide valuable information regarding autoregulation. Keywords: cerebrovascular reactivity, decompressive craniectomy, DC, PRx, TBI.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Neurologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Neurology (hsv//eng)

Nyckelord

Adult brain injury

Blood flow

CFB autoregulation

Traumatic brain injury

neurokirurgi

Neurosurgery

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)