The Effect of Clevidipine on Cerebral Blood Flow Velocity and Carbon Dioxide Reactivity in Human Volunteers

The Current Role of Clevidipine in the Management of Hypertension

Acute hypertension, which may damage blood vessels, causes irreversible organ damage to the vasculature, central nervous system, kidney, and heart. Clevidipine, the first third-generation calcium channel antagonist approved by the Food and Drug Administration (FDA) in the past 20 years, is an ultra-short-acting calcium channel blocker that inhibits L-type calcium channels with high clearance and low distribution, can be rapidly metabolized into the corresponding inactive acid, and is rapidly hydrolyzed into inactive metabolites by esterase in arterial blood. Clevidipine is the same as nicardipine in that the main physiological effect is vasodilation and the main target is the arterial system, which has a limited effect on capacitor vessels. Unlike nitroglycerin, clevidipine has a limited effect on preload. In contrast to other direct-acting vasodilators, clevidipine has an ultra-short half-life due to metabolism by nonspecific blood and tissue esterases. Clevidipine trials conducted in adult populations have proven that it can rapidly control blood pressure in cardiac surgery situations and that adverse reactions to clevidipine are similar to those with other antihypertensive agents. In recent years, clinical trials have shown that clevidipine has excellent blood pressure-lowering capability in patients with acute neurological injury (hemorrhage, stroke, and subarachnoid and acute intracerebral hemorrhage), those  undergoing coronary artery bypass graft or spinal surgery, and in those with cerebral aneurysm/pheochromocytoma, acute heart failure, acute aortic syndromes, or renal insufficiency with severe hypertension, and it is equivalent to commonly used blood pressure-lowering medicines such as nicardipine or nitroglycerin. However, there is a lack of large-scale clinical trial data on the efficacy and safety of clevidipine in children during the perioperative period.

Cerebral blood flow is reduced in ME/CFS during head-up tilt testing even in the absence of hypotension or tachycardia: A quantitative, controlled study using Doppler echography

OBJECTIVE

The underlying hypothesis in orthostatic intolerance (OI) syndromes is that symptoms are associated with cerebral blood flow (CBF) reduction. Indirect CBF measurements (transcranial Doppler flow velocities), provide inconsistent support of this hypothesis. The aim of the study was to measure CBF during a 30 min head-up tilt test (HUT), using Doppler flow imaging of carotid and vertebral arteries, in individuals with chronic fatigue syndrome/myalgic encephalomyelitis (ME/CFS), a condition with a high prevalence of OI.

METHODS

429 ME/CFS patients were studied: 247 had a normal heart rate (HR) and blood pressure (BP) response to HUT, 62 had delayed orthostatic hypotension (dOH), and 120 had postural orthostatic tachycardia syndrome (POTS). We also studied 44 healthy controls (HC). CBF measurements were made at mid-tilt and end-tilt. Before mid-tilt, we administered a verbal questionnaire to ascertain for 15 OI symptoms.

RESULTS

End-tilt CBF reduction was 7% in HC versus 26% in the overall ME/CFS group, 24% in patients with a normal HR/BP response, 28% in those with dOH, and 29% in POTS patients (all P < .0005). Using a lower limit of normal of 2SD of CBF reduction in HC (13% reduction), 82% of patients with normal HR/BP response, 98% with dOH and 100% with POTS showed an abnormal CBF reduction. There was a linear correlation of summed OI symptoms with the degree of CBF reduction at mid-tilt (P < .0005).

CONCLUSIONS

During HUT, extracranial Doppler measurements demonstrate that CBF is reduced in ME/CFS patients with POTS, dOH, and even in those without HR/BP abnormalities.

SIGNIFICANCE

This study shows that orthostatic intolerance symptoms are related to CBF reduction, and that the majority of ME/CFS patients (90%) show an abnormal cerebral flow reduction during orthostatic stress testing. This may have implications for the diagnosis and treatment of ME/CFS patients.

Clevidipine Versus Nicardipine for Acute Blood Pressure Reduction in a Neuroscience Intensive Care Population

BACKGROUND

Currently, a lack of published literature exists regarding the use of clevidipine in the neuroscience population. This agent may be preferred in some patients because of its short half-life, potentially leading to more narrow blood pressure (BP) control in comparison with other agents. The purpose of this study was to compare the difference in time to achieve target systolic blood pressure (SBP) goals with clevidipine versus nicardipine infusions in patients admitted to the neuroscience intensive care unit (NSICU) at our institution.

METHODS

A retrospective review was performed on patients receiving clevidipine or nicardipine infusions while in the NSICU between July 1, 2011 and June 30, 2014. Patients were matched based on indication for BP lowering and target SBP. Primary endpoints included time to target SBP and percentage of time within target BP range.

RESULTS

Of the 57 patients included in the study, the median time to target SBP was 30 min in the clevidipine group and 46 min in the nicardipine group (p = 0.13). The percentage of time spent within target BP range was 79 versus 78% (p = 0.64). Clevidipine administration resulted in significantly less volume administered per patient versus nicardipine (530 vs. 1254 mL, p = 0.02).

CONCLUSIONS

There were no statistically significant differences in acute BP management between the two agents; however, there was a trend toward shorter time to target and significantly less volume administered in the clevidipine group. Either agent should be considered a viable option in a NSICU population.