Blood Pressure Changes in Association with Nimodipine Therapy in Patients with Spontaneous Subarachnoid Hemorrhage

Nimodipine in Aneurysmal Subarachnoid Hemorrhage: Are Old Data Enough to Justify Its Current Treatment Regimen?

Nimodipine, a dihydropyridine L-type calcium channel antagonist, constitutes one of the mainstays of care to prevent delayed cerebral ischemia in patients with aneurysmal subarachnoid hemorrhage (aSAH) because it has been associated with a reduction in infarction rates and improvement in functional outcomes despite not significantly preventing angiographic vasospasm. Although it is a widely accepted treatment, controversies surrounding the current regimen of nimodipine in patients with aSAH exist. Still, there is a wide space open for randomized controlled trials or alternative study designs comparing different routes of administration, dosing, and timing of nimodipine treatment regimen in patients with aSAH.

Ultrasound-Induced Release Profile of Nimodipine from Drug-Loaded Block Copolymers after Singular vs. Repeated Sonication: In Vitro Analysis in Artificial Cerebrospinal Fluid

OBJECTIVE

Nimodipine still represents a unique selling point in the prevention of delayed cerebral ischemia (DCI) following aneurysmal subarachnoid hemorrhage (aSAH). Its intrathecal effect is limited by a low oral bioavailability, leading to the development of nanocarrier systems to overcome this limitation. This study investigated the ultrasound-induced release profile of nimodipine from drug-loaded copolymers in artificial cerebrospinal fluid (CSF) within 72 h after a singular versus repeated sonication.

METHODS

Pluronic® F127 copolymers (Sigma-Aldrich, Taufkirchen, Germany)were loaded with nimodipine by direct dissolution. Spontaneous and on-demand drug release by ultrasound (1 MHz at 1.7 W/cm2) was determined in artificial cerebrospinal fluid using the dialysis bag method. Nimodipine concentrations were measured at predefined time points within 72 h of sonication.

RESULTS

Spontaneous release of nimodipine was enhanced by ultrasound application with significantly increased nimodipine concentrations two hours after a repeated sonication compared to a singular sonication (median 1.62 vs. 17.48 µg/µL, p = 0.04). A further trend was observed after four hours (median 1.82 vs. 22.09 µg/µL, p = 0.06). There was no difference in the overall nimodipine concentrations between the groups with a singular versus repeated sonication (357.2 vs. 540.3 µg/µL, p = 0.60) after 72 h.

CONCLUSIONS

Repeated sonication resulted in an acceleration of nimodipine release from the drug-loaded copolymer in a CSF medium. These findings confirm the proof of principle of an on-demand guidance of nimodipine release from nimodipine-loaded nanodrugs by means of ultrasound, which suggests that evaluating the concept in an animal model may be appropriate.

Contemporary management of aneurysmal subarachnoid haemorrhage. An update for the intensivist

Aneurysmal subarachnoid haemorrhage (aSAH) is a rare yet profoundly debilitating condition associated with high global case fatality and morbidity rates. The key determinants of functional outcome include early brain injury, rebleeding of the ruptured aneurysm and delayed cerebral ischaemia. The only effective way to reduce the risk of rebleeding is to secure the ruptured aneurysm quickly. Prompt diagnosis, transfer to specialized centers, and meticulous management in the intensive care unit (ICU) significantly improved the prognosis of aSAH. Recently, multimodality monitoring with specific interventions to correct pathophysiological imbalances has been proposed. Vigilance extends beyond intracranial concerns to encompass systemic respiratory and haemodynamic monitoring, as derangements in these systems can precipitate secondary brain damage. Challenges persist in treating aSAH patients, exacerbated by a paucity of robust clinical evidence, with many interventions showing no benefit when tested in rigorous clinical trials. Given the growing body of literature in this field and the issuance of contemporary guidelines, our objective is to furnish an updated review of essential principles of ICU management for this patient population. Our review will discuss the epidemiology, initial stabilization, treatment strategies, long-term prognostic factors, the identification and management of post-aSAH complications. We aim to offer practical clinical guidance to intensivists, grounded in current evidence and expert clinical experience, while adhering to a concise format.

Twelve controversial questions in aneurysmal subarachnoid hemorrhage

Critical care management of aneurysmal subarachnoid hemorrhage (aSAH) remains a major challenge. Despite the recent publication of guidelines from the American Heart Association/American Stroke Association and the Neurocritical Care Society, there are many controversial questions in the intensive care unit (ICU) management of this population. The authors provide an analysis of common issues in the ICU and provide guidance on the daily management of this specific population of neurocritical care patients.