Temporal relationship between vasopressor and sedative administration and cerebrovascular response in traumatic brain injury: a time-series analysis

Intensive Care Medicine Experimental

Table 2 Granger causality testing

Agent	Mean dose change	ICP and ABP	rSO2_L and ABP	rSO2_R and ABP	AMP and ABP	AMP and CPP
Norepinephrine	Increase	99.6	99.2	99.8	99.6	99.5
Norepinephrine	Decrease	99.8	99.6	99.7	99.8	99.6
Propofol	Increase	99.4	98.9	99.4	99.2	99.2
Propofol	Decrease	100	98.9	99.6	99.1	99.6
Fentanyl	Increase	98.9	98.9	98.9	98.9	98.9
Fentanyl	Decrease	98.9	98.4	98.9	98.9	98.9
Fentanyl	Bolus	98.9	98.4	98.9	98.9	98.9

The table shows from Granger testing the percent that the directional relationship remained the same pre/post dose change for each type of mean dose change, window type and agent. Given the similar proportions of number in the pre/post windows for each agent, it can be seen that the impact of said agent on the physiological relationship was minimal. ABP arterial blood pressure, AMP pulse amplitude of intracranial pressure, CPP cerebral perfusion pressure, ICP intracranial pressure, rSO2_L regional oxygen saturation on left side, rSO2_R regional oxygen saturation on right side