Early Experiences with Intrathecal Administration of Amphotericin B Liposomal Formulation at a Neurosurgical Center.

BACKGROUND: Intrathecal administration of amphotericin B represents an important adjunctive therapy for management of severe fungal meningitis. Intrathecal preparations have traditionally used amphotericin B deoxycholate. Liposomal amphotericin B is an alternative formulation with good clinical outcomes as systemic therapy, but scant data exist investigating intrathecal use. OBJECTIVE: The aim of this exploratory study was to evaluate outcomes following intrathecal administration of liposomal amphotericin B for treatment of severe fungal meningitis. METHODS: A national shortage of amphotericin B deoxycholate necessitated revision of institutional protocols at a southwestern neurosurgical center in Spring 2023. A starting intrathecal daily dose of 0.125-0.5 mg liposomal amphotericin B was recommended (dependent on insertion device), with 0.125-0.25 mg slow titration every 48 h and up to a 2 mg maximum daily dose. RESULTS: Four cases of fungal meningitis treated with adjunctive intrathecal amphotericin B liposomal formulation were reviewed. This included three cases of coccidioidal meningitis and one case of presumed Fusarium solani meningitis following an outbreak. All patients had initial disease improvement following initiation of intrathecal amphotericin B and were able to tolerate long-term therapy. One coccidioidal meningitis patient expired of neurologic complications shortly after being moved from the intensive care unit (ICU) to a floor unit. All other patients were successfully discharged from the hospital. New headache was the only reported adverse effect, which was managed with dose reduction and did not require therapy discontinuation. CONCLUSIONS: Liposomal amphotericin B may be feasibly administered intrathecally for the adjunctive treatment of severe fungal meningitis.

Rapid administration of undiluted loading doses of levetiracetam.

OBJECTIVE: Rapid administration of antiseizure medications is a critical concept in the treatment of status epilepticus. Although undiluted levetiracetam (LEV) doses of up to 2500 mg have been evaluated, minimal data exist to support the safety of loading doses up to 4500 mg. This study will evaluate intravenous (IV) push administration of undiluted LEV from 2500 to 4500 mg for safety outcomes as well as tolerability. METHODS: This is a retrospective, observational, cohort analysis of adult patients who received at least one loading dose of undiluted IV push LEV from October 15, 2019, to April 30, 2022, at a large academic medical center in Phoenix, Arizona. Relevant outcomes include the safety and tolerability of rapid administration of undiluted LEV at higher loading doses. RESULTS: We evaluated 518 loading doses in 518 unique patients included during the study period. LEV was a new medication for witnessed or suspected seizures in 80.3% of patients, with 31.2% having a documented history of epilepsy or seizure disorder. At the time of LEV administration, 52.9% of patients were on a general medicine floor, 34.3% were in the intensive care unit, and 12.7% were in the emergency department. The median loading dose of LEV was 3600 mg (3000-4000 mg), with 4000 mg being the most common loading dose given. Peripheral IV lines were documented as the only available line in 78.6% of patients for loading dose administration. No adverse events associated with LEV administration were documented. SIGNIFICANCE: Rapid IV administration of undiluted doses of LEV is both safe and tolerable in loading doses of 2500-4500 mg, allowing for rapid drug administration in the setting of status epilepticus.

Levetiracetam pharmacokinetics in critically ill patients undergoing renal replacement therapy.

PURPOSE: To determine clearance of levetiracetam in patients requiring continuous renal replacement therapy (CRRT) or sustained low efficiency dialysis (SLED). MATERIALS AND METHODS: Adult patients with acute kidney injury or end stage renal disease requiring either CRRT or SLED and levetiracetam were eligible for inclusion. Simultaneous arterial, venous, and effluent samples for analysis of levetiracetam concentrations were collected every two hours for up to 6-8 h. Levetiracetam clearance (CL) and half-life (t1/2) were calculated for each modality. RESULTS: Eight CRRT patients and 4 SLED patients completed the study: 67% male, mean age 50 ± 13 years, and 83% had AKI. Seven CRRT patients received continuous venovenous hemodiafiltration (CVVHDF) [median pre-replacement rate 700 mL/h (range 500-1000), post-replacement rate 500 mL/h (range 200-1000), effluent rate 2500 mL/h (range 1700-3650) and delivered CRRT dose 27 mL/kg/h (range 19-54)] and one patient received CVV hemofiltration (CVVH). The mm mean levetiracetam CL during CVVHDF was 31.2 ± 8.5 mL/min, and the and the mean t1/2 was 10.4 ± 2.2 h. For the patient requiring CVVH, clearance and t1/2 were 22.5 mL/min and 9.5 h, respectively. Mean levetiracetam CL during SLED performed at a blood flow rate of 250 mL/min and a dialysate flow rate of 100 mL/min was 74.0 ± 25.3 mL/min and t1/2 was 4.8 ± 2.3 h. CONCLUSIONS: Levetiracetam clearance was substantial with both modalities under the operating conditions reported. There is the potential for subtherapeutic concentrations with current recommended dosing strategies that account only for kidney function and not these extracorporeal routes of elimination.

An Association Between Hyperchloremia and Acute Kidney Injury in Patients With Acute Ischemic Stroke.

BACKGROUND AND PURPOSE: While an association between hyperchloremia and worse outcomes, such as acute kidney injury and increased mortality, has been demonstrated in hemorrhagic stroke, it is unclear whether the same relationship exists after acute ischemic stroke. This study aims to determine the relationship between moderate hyperchloremia (serum chloride ≥115 mmol/L) and acute kidney injury in patients with ischemic stroke. METHODS: This is a multicenter, retrospective, propensity-matched cohort study of adults admitted for acute ischemic stroke. The primary objective was to determine the relationship between moderate hyperchloremia and acute kidney injury, as defined by the Acute Kidney Injury Network criteria. Secondary objectives included mortality and hospital length of stay. RESULTS: A total of 407 patients were included in the unmatched cohort (332 nonhyperchloremia and 75 hyperchloremia) and 114 patients (57 in each group) were matched based upon propensity scores. In the matched cohort, hyperchloremia was associated with an increased risk of acute kidney injury (relative risk 1.91 [95% confidence interval 1.01-3.59]) and a longer hospital length of stay (16 vs 12 days; P = .03). Mortality was higher in the hyperchloremia group (19.3% vs 10.5%, P = .19), but this did not reach statistical significance. CONCLUSIONS: In this study, hyperchloremia after ischemic stroke was associated with increased rates of acute kidney injury and longer hospital length of stay. Further research is needed to determine which interventions may increase chloride levels in patients with acute ischemic stroke and the association between hyperchloremia and clinical outcomes.

Effect of Alteplase Administration on International Normalized Ratio in Patients With Acute Ischemic Stroke.

BACKGROUND/OBJECTIVE: Alteplase may elevate international normalized ratio (INR) results, although the exact rate of elevation occurrence is not firmly established in the literature. The purpose of this study is to determine the occurrence rate of INR elevation following alteplase administration. We also aimed to determine what factors are independently associated with the development of elevated INR following alteplase administration for ischemic stroke. METHODS: We conducted a multicenter, retrospective, cohort study of patients who received alteplase for acute ischemic stroke. Patients were screened for baseline INR measurement and a repeat value within 24 hours of alteplase administration. The primary outcome was the percent of patients who experienced ≥0.4-point increase in INR. Secondary outcomes included the rate of adverse bleeding events and identification of factors independently associated with elevated INR following alteplase administration. RESULTS AND CONCLUSIONS: Two hundred and sixty-one patients were included, with 44 (16.9%) patients having an INR increase of 0.4 or more. Patients with an INR increase ≥0.4 experienced a nonstatistically significant increase in bleeding episodes (8.8% vs 18.2%; P = .10). We identified African American race (odds ratio, 3.48, 95% confidence interval, 1.5-7.6; P = .002) as an independent predictor of INR increase ≥0.04. An INR elevation is common following receipt of alteplase for ischemic stroke. Those of African American race were at increased risk of INR elevation; however, more studies are needed to determine whether these patients are at a higher bleeding risk as a result of INR elevation.

Use of Intraventricular Medications in Critically Ill Patients: A Systematic Review.

New evidence and increased use of intracranial devices have increased the frequency of intraventricular (IVT) medication administration in the neurologic intensive care unit. Significant benefits and risks are associated with administration of medications directly into the central nervous system. This review summarizes important literature, along with key information for clinicians regarding the administration, dosing, monitoring, and adverse effects related to IVT medication usage. Multiple medications have supporting literature for their use in critically ill patients including amphotericin B, aminoglycosides, colistimethate, daptomycin, quinupristin/dalfopristin, vancomycin, alteplase, and nicardipine. Sterile preparation and delivery, along with different types of devices that support medication administration, are also reviewed. One randomized, placebo-controlled trial of alteplase demonstrated decreased mortality but no change in good functional outcome. Other reports of IVT medication use are mainly limited to case reports and retrospective case series. There is a need for increased research on the topic; however, several practical barriers decrease the likelihood of a large, placebo-controlled, prospective study for most indications. Providers should consider implementing protocols to maximize safety of IVT medication delivery to ensure optimal patient outcomes.

Acute Management of Hypertension Following Intracerebral Hemorrhage.

Intracerebral hemorrhage (ICH) is responsible for approximately 15% of strokes annually in the United States, with nearly 1 in 3 of these patients dying without ever leaving the hospital. Because this disproportionate mortality risk has been stagnant for nearly 3 decades, a main area of research has been focused on the optimal strategies to reduce mortality and improve functional outcomes. The acute hypertensive response following ICH has been shown to facilitate ICH expansion and is a strong predictor of mortality. Rapidly reducing blood pressure was once thought to induce cerebral ischemia, though has been found to be safe in certain patient populations. Clinicians must work quickly to determine whether specific patient populations may benefit from acute lowering of systolic blood pressure (SBP) following ICH. This review provides nurses with a summary of the available literature on blood pressure control following ICH. It focuses on intravenous and oral antihypertensive medications available in the United States that may be utilized to acutely lower SBP, as well as medications outside of the antihypertensive class used during the acute setting that may reduce SBP.