Clinical Study of the Safety and Efficacy of Analgesia-first Minimal Sedation as an Early Antihypertensive Treatment for Spontaneous Intracerebral Hemorrhage

Spontaneous intracerebral hemorrhage (ICH) is hemorrhage in the brain parenchyma caused by non-traumatic spontaneous rupture of cerebral artery, arteriole, vein and capillary in adults. ICH is a common problem, with subarachnoid hemorrhage. About 90% ICH patients have increased blood pressure (BP) that usually occurs immediately after disease onset. BP elevation in the acute phase of ICH is associated with poor prognosis, and its mechanism of action includes the local increase of initial hemorrhage, early hematoma expansion at hemorrhagic sites, the increased risk of early recurrent hemorrhage, serious cerebral edema, and recurrent stroke, this affects the most within the few hours following the onset of the disease. The current American Heart Association guidelines recommended early antihypertensive treatment and suggested that rapid decrease of BP to 140 mmHg is safe in ICH patients with no obvious antihypertensive contraindications. However, the significant differences between large studies conducted in recent years have led to great controversy on the effect of early antihypertensive treatment in acute ICH and disease prognosis. A meta-analysis of early antihypertensive treatment for ICH showed that differences in early BP control rate and BP increase variability are also the major causes of inconsistency between these studies. There is currently no consensus on the best antihypertensive regimen as it is difficult to reach the optimal BP level timely. Some studies have shown that stress response, pain, ICP increase and pre-onset BP elevation are factors that cause acute BP increase in ICH patients. In particular, restlessness, sleep deprivation, and stress due to intolerable pain can lead to dramatic BP and intracranial pressure (ICP) increases, further lead to secondary intracerebral hematoma expansion and subsequently cause neurologic degeneration and cerebral tissue damage. Therefore, the primary principles of ICH acute BP increase treatment are to keep quiet, restore BP to normal level, stably reduce BP, decrease BP variability, lower the chance of recurrent hemorrhage, and thereby improve long-term prognosis. Traditional antihypertensive treatment can only resolve the issue of BP elevation but not the root cause of disease. Analgesia and sedation is a critical component of and a global consensus in the clinical management of ICH patients. Remifentanil is a fentanyl μ-type opioid receptor agonist with strong and fast-acting analgesic effects, does not induce ICP elevation and can alleviate pain induced by sputum aspiration, body turning and back clapping in severe patients. A randomized trial on patients with craniocerebral injury has indicated that a remifentanil-based sedation strategy can significantly reduce the amount of sedative used and shorten the time of mechanical ventilation without affecting the functional assessment of the nervous system. Dexmedetomidine is an α2-adrenergic agonist that inhibits sympathetic activity by activating the pre-synaptic α2-receptor in the locus coeruleus, which in turn reduces norepinephrine release, that only slightly affects consciousness and breathing and helps patients with craniocerebral injury stay conscious while under sedation, allowing real-time functional assessment of the nervous system. Therefore, the research group developed a treatment strategy in which sufficient analgesia is applied in combination with a minimal sedation program as an effective and safe early an- tihypertensive treatment.We hypothesize that applying sufficient analgesia in combination with a minimal sedation program will involve the use of remifentanil for pain relief and dexmedetomidine for antisympathetic activity to restore elevated BP to normal levels in patients with spontaneous ICH, and we further hypothesize that this strategy will be more effective than conventional symptomatic antihypertensive treatment for controlling BP.