From the Guidelines
Burst suppression is indicated in adult ICU patients with either known or suspected seizures, or to titrate electrosuppressive medication to achieve burst suppression in adult ICU patients with elevated intracranial pressure, as recommended by the clinical practice guidelines for the management of pain, agitation, and delirium in adult patients in the intensive care unit 1. The protocol for burst suppression typically involves continuous EEG monitoring while administering anesthetic agents to achieve 6-10 bursts per minute or suppression periods of 2-10 seconds. Some key points to consider when implementing burst suppression in the ICU include:
- First-line agents for burst suppression include propofol, midazolam, or pentobarbital, with ketamine as an adjunct 1
- The choice of sedative agent should be driven by specific indications and sedation goals for each patient, as well as the clinical pharmacology of the drug and its side effect profile 1
- Maintaining lighter levels of sedation in ICU patients is associated with improved clinical outcomes, and brain function monitors can be used to monitor depth of sedation in patients receiving neuromuscular blocking agents 1
- EEG monitoring should be used to monitor non-convulsive seizure activity in ICU patients at risk for seizures, and to titrate burst suppression therapy in ICU patients with elevated intracranial pressure 1
- Regular assessment of liver and kidney function is essential, as is monitoring for propofol infusion syndrome with prolonged high-dose administration
- Burst suppression works by profoundly decreasing cerebral metabolic demand and neural activity, potentially breaking the cycle of excitotoxicity in seizures or reducing metabolic needs in injured brain tissue. Some of the key benefits of burst suppression include:
- Improved outcomes in patients with refractory status epilepticus or severe traumatic brain injury
- Reduced metabolic needs in injured brain tissue
- Potential to break the cycle of excitotoxicity in seizures However, burst suppression also carries some risks, including:
- Hypotension requiring vasopressors
- Metabolic acidosis with propofol
- Immunosuppression
- Ileus
- Propofol infusion syndrome with prolonged high-dose administration.
From the FDA Drug Label
The rate of administration and the dosage of propofol injectable emulsion should be reduced to approximately 80% of the usual adult dosage in these patients according to their condition, responses, and changes in vital signs. For intubated, mechanically ventilated adult patients, Intensive Care Unit (ICU) sedation should be initiated slowly with a continuous infusion in order to titrate to desired clinical effect and minimize hypotension. When indicated, initiation of sedation should begin at 5 mcg/kg/min (0.3 mg/kg/h). The infusion rate should be increased by increments of 5 mcg/kg/min to 10 mcg/kg/min (0. 3 mg/kg/h to 0.6 mg/kg/h) until the desired level of sedation is achieved.
The indications for propofol in the Intensive Care Unit (ICU) include:
- Continuous sedation and control of stress responses in intubated, mechanically ventilated adult patients The protocol for burst suppression in the ICU is not explicitly stated in the provided drug labels. However, the protocol for ICU sedation is as follows:
- Initiate sedation slowly with a continuous infusion
- Start at 5 mcg/kg/min (0.3 mg/kg/h)
- Increase infusion rate by 5 mcg/kg/min to 10 mcg/kg/min (0.3 mg/kg/h to 0.6 mg/kg/h) until desired level of sedation is achieved
- Maintain minimal level of sedation throughout weaning process and when assessing level of sedation 2 2 2
From the Research
Indications for Burst Suppression
- Burst suppression is used in medical coma, a drug-induced brain state, to help recovery after brain injuries and to treat epilepsy that is refractory to conventional drug therapies 3
- It is also used as an electrophysiological endpoint in pharmacologically induced coma for brain protection after traumatic injury and during status epilepticus 4
- In nonconvulsive status epilepticus (NCSE), treating to burst-suppression is considered as an option to stop NCSE, especially when combined with acute brain injury 5
Protocol for Burst Suppression
- The state of coma is maintained manually by administering an intravenous infusion of an anesthetic, such as propofol, to target a pattern of burst suppression on the EEG 3
- A brain-machine interface (BMI) can be used to automate the control of drug infusion rate to track a desired target burst suppression trajectory 3, 6
- The burst suppression level can be quantified using the burst suppression probability (BSP), which is the brain's instantaneous probability of being in the suppressed state 3
- Automatic detection of burst suppression events can be achieved using a novel method based on segmentation and detection of the suppression component of the BS event using integrated EEG signal across the channels of interest 7
Considerations and Risks
- The risks of burst-suppression are common to many intensive care interventions and can be minimized with expert management 5
- Treating with coma-inducing medication is highly risky and has a high mortality rate, often due to iatrogenic complications 5
- It remains unclear if nonconvulsive seizures cause permanent neuronal injury, and nonconvulsive seizures should be diagnosed and treated as quickly as possible, but with non-coma-inducing treatments in most cases 5