From the Guidelines
Sedation is crucial in managing intracranial pressure (ICP) by mitigating cough and changes in ICP and cerebral perfusion pressure (CPP) during tracheal suctioning, as evidenced by a prospective crossover study 1.
Key Points
- Sedation helps reduce cerebral metabolic demand and prevents activities that can raise ICP, such as coughing, straining, and agitation.
- The combination of opioids and neuromuscular blocking agents (NMBAs) therapy can reduce suctioning-induced ICP elevation more than opioids alone 1.
- All currently available NMBAs appear to have minimal effects on ICP and systemic blood pressure in most patients when administered as a single dose 1.
- However, the use of NMBAs has been associated with longer length of stay, more pneumonia, and a higher proportion of survivors with persistent vegetative state or severe disability in patients with traumatic brain injury 1.
Sedation Management
- Sedation should be titrated to the minimum effective dose to allow neurological assessments when possible.
- The choice of sedative should be based on patient-specific and drug-specific factors, such as comorbidities, onset, offset, and route of elimination.
- Propofol, midazolam, and dexmedetomidine are commonly used sedatives, which decrease cerebral oxygen consumption, blood flow, and subsequently ICP.
- Deep sedation may be necessary for patients with severe ICP elevations, often targeting a Richmond Agitation-Sedation Scale (RASS) of -4 to -5.
From the FDA Drug Label
As CSFP is an indirect measure of intracranial pressure (ICP), propofol injectable emulsion, when given by infusion or slow bolus in combination with hypocarbia, is capable of decreasing ICP independent of changes in arterial pressure.
Sedation with propofol helps with intracranial pressure by decreasing ICP. This effect is seen when propofol is given by infusion or slow bolus in combination with hypocarbia. The decrease in ICP is independent of changes in arterial pressure 2.
- Key points:
- Propofol decreases ICP
- Effect is seen with infusion or slow bolus administration
- Combination with hypocarbia is necessary
- Decrease in ICP is independent of changes in arterial pressure
From the Research
Sedation and Intracranial Pressure Management
- Sedation is a critical component in the management of intracranial pressure (ICP) in patients with traumatic brain injury (TBI) 3, 4, 5.
- The primary goal of sedation in TBI patients is to prevent secondary brain injury by regulating cerebral metabolism and reducing ICP 3.
- Various sedative agents, including propofol, benzodiazepines, narcotics, barbiturates, etomidate, ketamine, and dexmedetomidine, are used to manage ICP in TBI patients 4, 5, 6.
Effectiveness of Sedative Agents
- Propofol and midazolam are effective in achieving sedation without notable differences in efficacy or safety, although high-dose propofol may disrupt cerebral autoregulation 4.
- Dexmedetomidine and propofol/dexmedetomidine combination may cause clinically significant hypotension, but dexmedetomidine is effective in achieving a target sedation score 4, 6.
- Ketamine bolus and infusions are not associated with increased ICP and may reduce the incidence of cortical spreading depolarization events 4.
Sedation Techniques and Monitoring
- Continuous monitoring and titration of sedatives are crucial to achieve the intended treatment goals and prevent sedative-related complications 3.
- Multimodal monitoring, including intracranial pressure, brain temperature, oximetry, and microdialysis, can help assess the cerebral physiologic effects of sedation 6.
- The use of sedation scales, such as the Richmond Agitation Sedation Scale, can help guide sedation management and ensure effective sedation 6.