HHE Emergency care supplement 2018 - Page 9

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 manoeuvers, and improve adaptation to mechanical ventilation. However, it has its 9 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 self- extubation, 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