emergency and critical care
Sedation in neurocritical care
Sedation is an essential therapeutic strategy in the care of neurocritical patients . Potential benefits and risks of limiting deep sedation and daily interruption of sedation remain unclear
Berta Monleón MD
Cristina Álvarez MD
Rafael Badenes MD PhD Department Anesthesiology and Surgical-Trauma Intensive Care , Hospital Clinic Universitari de València , Spain . University of Valencia
Sedation is one of the main facilities in the intensive care unit ( ICU ). However , it is well known that no sedation , or minimising it , results in better outcomes , such as decreased length of hospital stay , shorter duration of mechanical ventilation , reduced healthcare costs and a reduced need for additional examinations to determine brain function . It is also related to early mobilisation of the patient , but it is unclear if it decreases delirium . Most of the review studies supporting this evidence are based on populations with non-acute brain injury . Traditionally , these patients were kept under sedation in the early phase to prevent the secondary insult . 1 , 2
Sedation in the ICU has different roles . The drugs used are intravenous , such as propofol and midazolam . 2 The objective is to control pain and anxiety , reduce agitation and achieve patient – ventilator synchrony . Nonetheless , there are situations where sedation has specific roles such as in patients with high intracranial pressure ( ICP ), those requiring muscular relaxation for any reason , and those with a status epilepticus . 2
The trend now is to interrupt sedation as soon as possible and avoid it during the day . However , these two new settings have to be analysed and compared with the benefit they may have concerning the risk of exacerbating intracranial hypertension in patients with reduced brain compliance . 1
The ideal sedative drug should be able to decrease ICP and maintain an appropriate cerebral perfusion without interfering with its autoregulation . Additionally , it should decrease the cerebral metabolic rate of oxygen and have neuroprotective and anticonvulsant properties . In regard to its pharmacological properties , it should have a predictable response , rapid onset and wake-up , and minimum secondary effects . 2
There are no management of sedation guidelines in neurocritical patients . Each ICU bases its decisions on its own experiences and follows basic recommendations that are well accepted in the scientific community ; however , we need to establish algorithms for the management of sedation these patients .
Need for sedation Sedation in neurocritical patients is essential to relieve pain , anxiety , reduce ICP , decrease oxygen consumption , tolerate therapeutic manoeuvres , and improve adaptation to mechanical ventilation . However , it has its
69 HHE 2018 | hospitalhealthcare . com drawbacks . It prevents frequent neurological evaluation , thus decreasing prognostic capacity because clinicians are incapable of detecting changes in the brain state .
By contrast , sedation is part of management in certain other conditions ; targeted temperature management , elevated ICP and refractory status epilepticus . 1 It is a first-line treatment when ICP is high , together with other measures . In most cases , elevated ICP develops within 48 hours of the brain insult ; however , it can develop earlier than this .
Prolonged deep sedation might possibly worsen cognitive results after its cessation and contribute to polyneuropathy in critical patients . Unless deep sedation or general anaesthesia is necessary , analgesia must precede sedation . Nowadays , there is a new trend to base sedation on opioids . 3
The guidelines for sedoanalgesia in massive cerebral infarction establish the following recommendations : 4
• Analgesia and sedation are recommended if signs of pain , anxiety , or agitation arise ( strong recommendation , very low quality of evidence )
• The lowest possible sedation intensity and earliest possible sedation cessation is recommended , while avoiding physiological instability and discomfort ( strong recommendation , very low quality of evidence )
• The routine use of daily wake-up trials is not recommended . Caution is particularly warranted in patients prone to ICP crisis . Neuromonitoring of at least ICP and CPP is recommended to guide sedation , and daily wake-up trials should be abandoned or postponed at signs of physiological compromise or discomfort .
Sedation assessment Neurophysiological monitoring should be considered a routine practice for neurocritical patients requiring sedation . Over-sedation increases the risk of infection , delays the removal of mechanical ventilation , and increases the length of stay in ICUs . On the other hand , infrasedation causes agitation , anxiety , and risk of accidents such as selfextubation , pulling out of catheters , discomfort , or ventilator asynchronies 5 and has prevented neurologic deterioration . 6 , 7
A number of scales to evaluate arousal , deep of sedation and response to stimuli are available : 8
• Ramsay Scale : evaluates consciousness