Transcranial Doppler Monitoring of Intracranial Pressure Therapy with Mannitol, Sorbitol and Glycerol in Patients with Acute Stroke

Abstract

Introduction: The noninvasive management of the conservative therapy for intracranial pressure (ICP) with hyperosmolar substances is a central problem in the treatment of brain edema. Using transcranial Doppler (TCD), a continuous monitoring of ICP is now possible, because the TCD pulsatility index (PI) intraindividually closely correlates with the level of ICP. Patients and Methods: We administered an ICP-lowering treatment 113 times in 10 patients with intracranial bleeding or ischemic stroke who also had signs of elevated ICP in the computer tomogram. The treatment was carried out over a period of 9 days, using 50 g each of intravenous sorbitol (n = 38) and mannitol (n = 32) or oral glycerol (n = 43). Results: PI was significantly lowered between 20.0 and 23.9% (p < 0.01) by all substances in the affected and unaffected sides. The differences between the three substances and the differences between the affected and unaffected sides were not significant. The duration of the therapeutic effect of glycerol (190 ± 41 min) was significantly longer (p < 0.01) than that of sorbitol (150 ± 28 min) or mannitol (130 ± 20 min). The duration of the therapeutic effect was also significantly shorter (p < 0.01) in patients with a high PI (> 1.5). All three substances led to a significant increase (p < 0.01) in minimal (= diastolic) flow velocity (V_min). The increase was highest for glycerol (56.3 ±72.6%). Summary: The decrease in PI under therapy was caused by an increase in V_min. This indicates that ICP therapy with hyperosmolar substances improves brain edema and does not suggest a therapy-induced vasoconstriction.

Association of Pretreatment Blood Pressure With Tissue Plasminogen Activator-Induced Arterial Recanalization in Acute Ischemic Stroke

“…20 Interestingly, in the present study, higher pretreatment SBP values were observed in patients with persisting high-resistance occlusions. Because brain swelling is associated with increased resistance to residual blood flow, 21,22 it may be assumed that high pretreatment blood pressure values by exacerbating early brain swelling could have a possible detrimental effect on vessel recanalization. In addition, cyto- toxic edema can impede microcirculation in the core of infarction during the first 3 hours of ictus as seen in animal models of the MCA occlusion.…”

Recommendations for the Management of Cerebral and Cerebellar Infarction With Swelling

“…29,61,62 Other descriptions include effacement of the ipsilateral sulci and lateral ventricle 63 and CT signs of elevated ICP. 64 Most commonly, the degree of midline shift is used as the benchmark for radiographic deterioration, either undefined 16,60,65 or specified as >5 mm at the level of septum pellucidum, 19,41,47,[66][67][68] >2 mm at the level of septum pellucidum or pineal gland, 69,70 or >10 mm. 71 Although all these arbitrary parameters are indicative of tissue shift, further development and validation of serial CT measures that identify patients at highest risk of clinical deterioration are required.…”

Unsolved Issues in the Management of High Blood Pressure in Acute Ischemic Stroke

“…The reason for poor outcome after initial high blood pressure seems more complex. High blood pressure after acute ischemic stroke causes brain edema [10], and brain edema decreases cerebral blood flow [11, 12], thus aggravating cerebral ischemia. Another mechanism could be that endogenous tPA release is reduced when blood pressure is high due to the damage at the endothelium [13–15].…”