Buprenorphine in the Intensive Care Unit: Commentary on the Unanswered Questions

The removal of the X-waiver in the Mainstreaming Addiction Treatment (MAT) Act of 2023 has substantial implications for buprenorphine prescribing as one of the options to treat opioid use disorder. The purpose of this commentary is to discuss the unanswered questions regarding buprenorphine in the intensive care unit (ICU) including how the passage of the MAT Act will affect ICU providers, which patients should receive buprenorphine, what is the most appropriate route of administration and dose of buprenorphine, what medications interact with buprenorphine, and how can transitions of care be optimized for these patients.

Delayed CCL23 response is associated with poor outcomes after cardiac arrest

Chemokines, a family of chemotactic cytokines, mediate leukocyte migration to and entrance into inflamed tissue, contributing to the intensity of local inflammation. We performed an analysis of chemokine and immune cell responses to cardiac arrest (CA). Forty-two patients resuscitated from cardiac arrest were analyzed, and twenty-two patients who underwent coronary artery bypass grafting (CABG) surgery were enrolled. Quantitative antibody array, chemokines, and endotoxin quantification were performed using the patients blood. Analysis of CCL23 production in neutrophils obtained from CA patients and injected into immunodeficient mice after CA and cardiopulmonary resuscitation (CPR) were done using flow cytometry. The levels of CCL2, CCL4, and CCL23 are increased in CA patients. Temporal dynamics were different for each chemokine, with early increases in CCL2 and CCL4, followed by a delayed elevation in CCL23 at forty-eight hours after CA. A high level of CCL23 was associated with an increased number of neutrophils, neuron-specific enolase (NSE), worse cerebral performance category (CPC) score, and higher mortality. To investigate the role of neutrophil activation locally in injured brain tissue, we used a mouse model of CA/CPR. CCL23 production was increased in human neutrophils that infiltrated mouse brains compared to those in the peripheral circulation. It is known that an early intense inflammatory response (within hours) is associated with poor outcomes after CA. Our data indicate that late activation of neutrophils in brain tissue may also promote ongoing injury via the production of CCL23 and impair recovery after cardiac arrest.

A multi-center, randomized, double blinded, placebo-controlled trial of amantadine to stimulate awakening in comatose patients resuscitated from cardiac arrest

Objectives

We hypothesized that the administration of amantadine would increase awakening of comatose patients resuscitated from cardiac arrest.

Methods

We performed a prospective, randomized controlled pilot trial, randomizing subjects to amantadine 100mg twice daily or placebo for up to 7 days. The study drug was administered between 72-120 hours after resuscitation and patients with absent N20 cortical responses, early cerebral edema, or ongoing malignant electroencephalography patterns were excluded. Our primary outcome was awakening, defined as following two-step commands, within 28 days of cardiac arrest. Secondary outcomes included length of stay, awakening, time to awakening, and neurologic outcome measured by Cerebral Performance Category (CPC) at hospital discharge. We compared the proportion of subjects awakening and hospital survival using Fisher's exact tests and time to awakening and hospital length of stay using Wilcoxon rank sum tests.

Results

After 2 years, we stopped the study due to slow enrollment and lapse of funding. We enrolled 14 subjects (12% of goal enrollment), 7 in the amantadine arm and 7 in the placebo arm. The proportion of patients who awakened within 28 days after cardiac arrest did not differ between amantadine (n=2, 28.57%) and placebo groups (n=3, 42.86%) (p = 1.00). There were no differences in secondary outcomes. Study medication was stopped in three (21%) subjects. Adverse events included a recurrence of seizures (n=2; 14%), both of which occurred in the placebo arm.

Conclusion

We could not determine the effect of amantadine on awakening in comatose survivors of cardiac arrest due to small sample size.

Medications for opioid use disorder prescribed at hospital discharge associated with decreased opioid agonist dispensing in patients with opioid use disorder requiring critical care: A retrospective study

INTRODUCTION

Buprenorphine is highly effective for the treatment of opioid use disorder (OUD), and, in recent years, the rates of patients maintained on buprenorphine requiring critical care have been steadily increasing. Currently, no unified guidance exists for buprenorphine management during critical illness. Likewise, we do not know if patients maintained on buprenorphine for OUD are prescribed medications for OUD (MOUD) following hospital discharge or if buprenorphine management influences mu opioid agonist dispensing.

METHODS

In our cohort of adults over the age of 18 with OUD, receiving buprenorphine formulations in the 3 months preceding their ICU admission, we sought to investigate the relationship between receipt of MOUD and non-MOUD opioid prescribing up to 12 months following hospital discharge. This was a single-center, retrospective cohort study approved by the MaineHealth institutional review board. The study analyzed differences in prescription rates between discharge and subsequent time points using chi square or Fisher's exact test, as appropriate. We performed analyses using SPSS Statistical Software version 28 (IBM SPSS Inc., Armonk, NY) with significance set at p < 0.05.

RESULTS

We identified a statistically significant increase in MOUD prescribing 3 months posthospital discharge in patients who received MOUD at time of discharge (87.9 % vs 40 % p = 0.002.) The study found a significant increase in nonbuprenorphine opioid prescribing in patients who did not receive an MOUD prescription at time of discharge (24.2 % vs 70 % p = 0.007). This trend persisted at the 6-month and 12-month time points; however, it did not reach statistical significance. Additionally, the study identified a significant reduction in the incidence of non-MOUD opioid dispensing in patients prescribed MOUD at each time point measured (p = 0.007, p < 0.001. p < 0.001 and p = 0.008 at discharge, 3, 6, and 12 months, respectively).

CONCLUSIONS

These findings support continuing buprenorphine dispensing following hospital discharge.

Derivation and Validation of a New Equation for Estimating Free Valproate Concentration in Critically Ill Adult Patients

IMPORTANCE

Protein binding of valproate varies among ICU patients, altering the biologically active free valproate concentration (VPAC). Free VPAC is measured at few laboratories and is often discordant with total VPAC. Existing equations to predict free VPAC are either not validated or are inaccurate in ICU patients.

OBJECTIVES

We designed this study to derive and validate a novel equation to predict free VPAC using data from ICU patients and to compare its performance to published equations.

DESIGN

Retrospective cohort study.

SETTING

Two academic medical centers.

PARTICIPANTS

Patients older than 18 years old with concomitant free and total VPACs measured in the ICU were included in the derivation cohort if admitted from 2014 to 2018, and the validation cohort if admitted from 2019 to 2022.

MAIN OUTCOMES AND MEASURES

Multivariable linear regression was used to derive an equation to predict free VPAC. Modified Bland-Altman plots and the rate of therapeutic concordance between the measured and predicted free VPAC were compared.

RESULTS

Demographics, median free and total VPACs, and valproate free fractions were similar among 115 patients in the derivation cohort and 147 patients in the validation cohort. The Bland-Altman plots showed the new equation performed better (bias, 0.3 [95% limits of agreement, -13.6 to 14.2]) than the Nasreddine (-9.2 [-26.5 to 8.2]), Kodama (-9.7 [-30.0 to 10.7]), Conde Giner (-7.9 [-24.9 to 9.1]), and Parent (-9.9 [-30.7 to 11.0]) equations, and similar to Doré (-2.0 [-16.0 to 11.9]). The Doré and new equations had the highest therapeutic concordance rate (73%).

CONCLUSIONS AND RELEVANCE

For patients at risk of altered protein binding such as ICU patients, existing equations to predict free VPAC are discordant with measured free VPAC. A new equation had low bias but was imprecise. External validation should be performed to improve its precision and generalizability. Until then, monitoring free valproate is recommended during critical illness.

Buprenorphine Continuation During Critical Illness Associated With Decreased Inpatient Opioid Use in Individuals Maintained on Buprenorphine for Opioid Use Disorder in a Retrospective Study

The number of patients maintained on buprenorphine is steadily increasing. To date, no study has reported buprenorphine management practices for these patients during critical illness, nor its relationship with supplemental full-agonist opioid administration during their hospital stay. In this single-center retrospective study, we have explored the incidence of buprenorphine continuation during critical illness among patients receiving buprenorphine for the treatment of opioid use disorder. Additionally, we investigated the relationship between nonbuprenorphine opioid exposure and buprenorphine administration during the intensive care unit (ICU) and post-ICU phases of care. Our study included adults maintained on buprenorphine for opioid use disorder admitted to the ICU between December 1, 2014, and May 31, 2019. Nonbuprenorphine, full agonist opioid doses were converted to fentanyl equivalents (FEs). Fifty-one (44%) patients received buprenorphine during the ICU phase of care, with an average dose of 8 (8-12) mg/day. During the post-ICU phase of care, 68 (62%) received buprenorphine, with an average dose of 10 (7-14) mg/day. Lack of mechanical ventilation and acetaminophen use were also associated with buprenorphine use. Full agonist opioid use was more frequent on days when buprenorphine was not given (odds ratio [OR], 6.2 [95% CI, 2.3-16.4]; P < .001). Additionally, the average cumulative dose of opioids given on nonbuprenorphine administration days was significantly higher both in the ICU (OR, 1803 [95% CI, 1271-2553] vs OR, 327 [95% CI, 152-708] FEs/day; P < 0.001) and after ICU discharge (OR, 1476 [95% CI, 962-2265] vs OR, 238 [95% CI, 150-377] FEs/day; P < .001). Given these findings, buprenorphine continuation during critical illness should be considered, as it is associated with significantly decreased full agonist opioid use.

The number of circulating CD26 expressing cells is decreased in critical COVID-19 illness

We evaluated the number of CD26 expressing cells in peripheral blood of patients with COVID-19 within 72 h of admission and on day 4 and day 7 after enrollment. The majority of CD26 expressing cells were presented by CD3+ CD4+ lymphocytes. A low number of CD26 expressing cells were found to be associated with critical-severity COVID-19 disease. Conversely, increasing numbers of CD26 expressing T cells over the first week of standard treatment was associated with good outcomes. Clinically, the number of circulating CD26 cells might be a marker of recovery or the therapeutic efficacy of anti-COVID-19 treatment. New therapies aimed at preserving and increasing the level of CD26 expressing T cells may prove useful in the treatment of COVID-19 disease.

Decreased circulating CD73 and adenosine deaminase are associated with disease severity in hospitalized patients with COVID-19

OBJECTIVE

SARS-CoV-2 infection has been shown to result in increased circulating levels of adenosine triphosphate and adenosine diphosphate and decreased levels of adenosine, which has important anti-inflammatory activity. The goal of this pilot project was to assess the levels of soluble CD73 and soluble Adenosine Deaminase (ADA) in hospitalized patients with COVID-19 and determine if levels of these molecules are associated with disease severity.

METHODS

Plasma from 28 PCR-confirmed hospitalized COVID-19 patients who had varied disease severity based on WHO classification (6 mild/moderate, 10 severe, 12 critical) had concentrations of both soluble CD73 and ADA determined by ELISA. These concentrations were compared to healthy control plasma that is commercially available and was biobanked prior to the start of the pandemic. Additionally, outcomes such as WHO ordinal scale for disease severity, ICU admission, needed for invasive ventilation, hospital length of stay, and development of thrombosis during admission were used as markers of disease severity.

RESULTS

Our results show that both CD73 and ADA are decreased during SARS-CoV-2 infection. The level of circulating CD73 is directly correlated to the severity of the disease defined by the need for ICU admission, invasive ventilation, and hospital length of stay. Low level of CD73 is also associated with clinical thrombosis, a severe complication of SARS-CoV-2 infection.

CONCLUSION

Our study indicates that adenosine metabolism is down-regulated in patients with COVID-19 and associated with severe infection. Further large-scale studies are warranted to investigate the role of the adenosinergic anti-inflammatory CD73/ADA axis in protection against COVID-19.

Community consultation for Exception from Informed consent (EFIC) before and during the COVID-19 pandemic

Aim

Describe community consultation and surrogate consent rates for two Exception From Informed Consent (EFIC) trials for out-of-hospital cardiac arrest (OOHCA) - before and during the COVID-19 pandemic.

Methods

The PEARL study (2016–2018) randomized OOHCA patients without ST-elevation to early cardiac catheterization or not. Community consultation included flyers, radio announcements, newspaper advertisements, mailings, and in-person surveys at basketball games and ED waiting rooms. The PROTECT trial (2021-present) randomizes OOHCA survivors to prophylactic ceftriaxone or placebo; the community consultation plan during the pandemic included city council presentations, social media posts, outpatient flyers, but no in-person encounters. Demographics for PROTECT community consultation were compared to PEARL and INTCAR registry data, with p-value < 0.05 considered significant.

Results

PEARL surveyed 1,362 adults, including 64 % ≥60 years old, 96 % high school graduates or beyond; research acceptance rate was 92 % for the community and 76 % for personal level. PROTECT initially obtained 221 surveys from electronic media – including fewer males (28 % vs 72 %,p < 0.001) and those > 60 years old (14 % vs 53 %;p < 0.001) compared to INTCAR. These differences prompted a revised community consultation plan, targeting 79 adult in-patients with cardiac disease which better matched PEARL and INTCAR data: the majority were ≥ 60 years old (66 %) and male (54 %). Both PEARL and PROTECT enrolled more patients using surrogate consent vs EFIC (57 %, 61 %), including 71 % as remote electronic consents during PROTECT.

Conclusions

Community consultation for EFIC studies changed with the COVID-19 pandemic, resulting in different demographic patterns. We describe effective adaptations to community consultation and surrogate consent during the pandemic.

Evaluation of Free Valproate Concentration in Critically Ill Patients

Protein binding of valproate is variable in ICU patients, and the total valproate concentration does not predict the free valproate concentration, even when correcting for albumin. We sought to quantify valproate free concentration among ICU patients, identify risk factors associated with an increasing free valproate concentration, and evaluate the association between free valproate concentration with potential adverse drug effect.

DESIGN

Retrospective multicenter cohort study.

SETTING

Two academic medical centers.

PATIENTS

Patients greater than or equal to 18 years of age with concomitant free and total valproate concentrations collected in the ICU.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Two-hundred fifty-six patients were included in the study, with a median age of 56 years (42-70) and 65% of patients were male. The median total valproate concentration was 53 µg/mL (38-70 µg/mL), the free valproate concentration was 12 µg/mL (7-20 µg/mL), and the free fraction was 23.6% (17.0-33.9%). Therapeutic discordance between the free and total valproate concentration occurred in 70% of patients. On multivariable analysis, increased free valproate concentration was associated with higher total valproate concentration (per 5 µg/mL increase, increase 1.72 µg/mL, 95% CI, 1.48-1.96) and lower serum albumin (per 1 g/dL decrease, increase 4.60 µg/mL, 95% CI, 2.71-6.49). There was no association between free valproate concentration and adverse effects.

CONCLUSIONS

The valproate total and free concentration was discordant in the majority of patients (70%). Increased valproate free concentration was associated with hypoalbuminemia and total valproate concentration. Clinical decisions based on total valproate concentration may be incorrect for many ICU patients. Prospective, controlled studies are needed to confirm these findings and their clinical relevance.

Perceptions Regarding the SARS-CoV-2 Pandemic's Impact on Neurocritical Care Delivery: Results From a Global Survey

BACKGROUND

The SARS-CoV-2 (COVID-19) pandemic has impacted many facets of critical care delivery.

METHODS

An electronic survey was distributed to explore the pandemic's perceived impact on neurocritical care delivery between June 2020 and March 2021. Variables were stratified by World Bank country income level, presence of a dedicated neurocritical care unit (NCCU) and experiencing a COVID-19 patient surge.

RESULTS

Respondents from 253 hospitals (78.3% response rate) from 47 countries (45.5% low/middle income countries; 54.5% with a dedicated NCCU; 78.6% experienced a first surge) participated in the study. Independent of country income level, NCCU and surge status, participants reported reductions in NCCU admissions (67%), critical care drug shortages (69%), reduction in ancillary services (43%) and routine diagnostic testing (61%), and temporary cancellation of didactic teaching (44%) and clinical/basic science research (70%). Respondents from low/middle income countries were more likely to report lack of surge preparedness (odds ratio [OR], 3.2; 95% confidence interval [CI], 1.8-5.8) and struggling to return to prepandemic standards of care (OR, 12.2; 95% CI, 4.4-34) compared with respondents from high-income countries. Respondents experiencing a surge were more likely to report conversion of NCCUs and general-mixed intensive care units (ICUs) to a COVID-ICU (OR 3.7; 95% CI, 1.9-7.3), conversion of non-ICU beds to ICU beds (OR, 3.4; 95% CI, 1.8-6.5), and deviations in critical care and pharmaceutical practices (OR, 4.2; 95% CI 2.1-8.2). Respondents from hospitals with a dedicated NCCU were less likely to report conversion to a COVID-ICU (OR, 0.5; 95% CI, 0.3-0.9) or conversion of non-ICU to ICU beds (OR, 0.5; 95% CI, 0.3-0.9).

CONCLUSION

This study reports the perceived impact of the COVID-19 pandemic on global neurocritical care delivery, and highlights shortcomings of health care infrastructures and the importance of pandemic preparedness.

Ceftriaxone to PRevent pneumOnia and inflammaTion aftEr Cardiac arresT (PROTECT): study protocol for a randomized, placebo-controlled trial

BACKGROUND

Pneumonia is the most common infection after out-of-hospital cardiac arrest (OHCA) occurring in up to 65% of patients who remain comatose after return of spontaneous circulation. Preventing infection after OHCA may (1) reduce exposure to broad-spectrum antibiotics, (2) prevent hemodynamic derangements due to local and systemic inflammation, and (3) prevent infection-associated morbidity and mortality.

METHODS

The ceftriaxone to PRevent pneumOnia and inflammaTion aftEr Cardiac arrest (PROTECT) trial is a randomized, placebo-controlled, single-center, quadruple-blind (patient, treatment team, research team, outcome assessors), non-commercial, superiority trial to be conducted at Maine Medical Center in Portland, Maine, USA. Ceftriaxone 2 g intravenously every 12 h for 3 days will be compared with matching placebo. The primary efficacy outcome is incidence of early-onset pneumonia occurring < 4 days after mechanical ventilation initiation. Concurrently, T cell-mediated inflammation bacterial resistomes will be examined. Safety outcomes include incidence of type-one immediate-type hypersensitivity reactions, gallbladder injury, and Clostridioides difficile-associated diarrhea. The trial will enroll 120 subjects over approximately 3 to 4 years.

DISCUSSION

The PROTECT trial is novel in its (1) inclusion of OHCA survivors regardless of initial heart rhythm, (2) use of a low-risk antibiotic available in the USA that has not previously been tested after OHCA, (3) inclusion of anti-inflammatory effects of ceftriaxone as a novel mechanism for improved clinical outcomes, and (4) complete metagenomic assessment of bacterial resistomes pre- and post-ceftriaxone prophylaxis. The long-term goal is to develop a definitive phase III trial powered for mortality or functional outcome.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04999592 . Registered on August 10, 2021.

DEspRhigh neutrophils are associated with critical illness in COVID-19

SARS-CoV-2 infection results in a spectrum of outcomes from no symptoms to widely varying degrees of illness to death. A better understanding of the immune response to SARS-CoV-2 infection and subsequent, often excessive, inflammation may inform treatment decisions and reveal opportunities for therapy. We studied immune cell subpopulations and their associations with clinical parameters in a cohort of 26 patients with COVID-19. Following informed consent, we collected blood samples from hospitalized patients with COVID-19 within 72 h of admission. Flow cytometry was used to analyze white blood cell subpopulations. Plasma levels of cytokines and chemokines were measured using ELISA. Neutrophils undergoing neutrophil extracellular traps (NET) formation were evaluated in blood smears. We examined the immunophenotype of patients with COVID-19 in comparison to that of SARS-CoV-2 negative controls. A novel subset of pro-inflammatory neutrophils expressing a high level of dual endothelin-1 and VEGF signal peptide-activated receptor (DEspR) at the cell surface was found to be associated with elevated circulating CCL23, increased NETosis, and critical-severity COVID-19 illness. The potential to target this subpopulation of neutrophils to reduce secondary tissue damage caused by SARS-CoV-2 infection warrants further investigation.

Vasopressin-Induced Hyponatremia in Patients With Aneurysmal Subarachnoid Hemorrhage: A Case Series and Literature Review

OBJECTIVE

Vasopressin may be administered to treat vasospasm following aneurysmal subarachnoid hemorrhage (aSAH). The objectives of this study were to describe five cases of suspected vasopressin-induced hyponatremia after aSAH and to review the literature.

DESIGN

Single-center, observational case series of intensive care unit (ICU) patients.

SETTINGS

Ten-bed neurological ICU at Maine Medical Center in Portland, Maine.

PATIENTS

Convenience sample of patients with aSAH treated with a vasopressin for symptomatic, radiologically confirmed vasospasm.

RESULTS

A total of five patients were included in the case series with a median age of 57 (51, 65) years and all were women. The median Glasgow coma scale score was 15 (11, 15) on admission, and the Hunt and Hess scale score was 3, (3, 4). All patients were treated with endovascular coiling of their aneurysm. Vasopressin was administered to treat symptomatic, radiographically confirmed vasospasm on median post-bleed day (PBD) 10 (10, 15) at a fixed-dose of .03 units/min. Serum sodium at baseline was 140 (140, 144) mEq/L and decreased to 129 (126, 129) mEq/L within 26 (17, 83) hours of vasopressin initiation for a median change of -16 (-10, -16) mEq/L. Serum sodium returned to baseline within 18 (14, 22) hours of stopping the infusion.

CONCLUSIONS

Vasopressin use in vasospasm after aSAH may be associated with clinically significant hyponatremia within 24 hours of starting the infusion. Hyponatremia appears to resolve within 24 hours of stopping the infusion. Additional study in a larger sample size is needed to determine if a causal relationship exist.

Heparin-induced thrombocytopenia with thrombosis in COVID-19 adult respiratory distress syndrome

Early reports of coronavirus disease 2019 (COVID-19) clinical features describe a hypercoagulable state, and recent guidelines recommend prophylactic anticoagulation for patients with COVID-19 with low-molecular-weight heparin, but this would be contraindicated in the presence of heparin-induced thrombocytopenia (HIT). We address the key clinical question whether HIT is also present during COVID-19. We report 3 cases of thrombocytopenia with antiplatelet factor 4 antibodies among 16 intubated patients with COVID-19 with adult respiratory distress syndrome, a higher-than-expected incidence of 19%. Each patient had evidence of thrombosis (pulmonary embolism, upper extremity venous thromboses, and skin necrosis, respectively). The serotonin release assay confirmed HIT in 1 case, and 2 cases were negative. We believe this is the first reported case of HIT during the COVID-19 pandemic. Recognition that the thrombocytopenia represented HIT in the confirmed case was delayed. We recommend clinicians monitor platelet counts closely during heparin therapy, with a low threshold to evaluate for HIT.

Pharmacist-Managed Inpatient Dofetilide Initiation Program: Description and Adherence Rate Post-Root Cause Analysis

The aim of this article is to describe the pharmacist-managed dofetilide initiation program at Maine Medical Center (MMC), assess the adherence rate to 8 core clinical metrics, and review adverse effects before and after a root cause analysis (RCA). Core clinical metrics included pharmacist note entered within 4 hours of dose administration, dose chosen correctly per renal function, QTc measurements obtained and reviewed 2 hours after each dose, appropriate dose adjustment per the most recent QTc measurement, documentation of patient education, and assessment of conduction abnormality, drug-drug interactions, and serum potassium and magnesium concentrations. The primary outcome was adherence rate to all 8 core clinical metrics before and after the RCA. The safety outcome was the total number of adverse events. One hundred patients undergoing elective dofetilide initiation were evaluated: 50 pre-RCA and 50 post-RCA. Adherence rate to all core metrics was 14% in the pre-RCA group and 44% in the post-RCA group (P < .001). Torsade de pointes occurred 3 times in the pre-RCA group and never in the post-RCA group. After the RCA, adherence to MMC's pharmacist-managed inpatient dofetilide initiation program significantly improved.

An Analysis of Psychoactive Medications Initiated in the ICU but Continued Beyond Discharge: A Pilot Study of Stewardship

BACKGROUND

Psychoactive medications (PM) are frequently administered in the intensive care unit (ICU) to provide comfort. Interventions focused on preventing their continuation after the acute phase of illness are needed.

OBJECTIVE

To determine the frequency that patients with ICU-initiated PM are continued upon ICU and hospital discharge.

METHODS

This single-center, prospective, observational study assessed consecutive adult ICU patients who received scheduled PM. Frequency of PM continued at ICU and hospital discharge was recorded. The patient's primary treatment team was contacted by the pharmacist within 72 hours of ICU discharge to establish rationale for continued use or to suggest discontinuation.

RESULTS

Of the 60 patients included, 72% were continued on PM at ICU discharge and 30% at hospital discharge. The pharmacist contacted 40% of treatment teams after ICU discharge and intervention resulted in PM discontinued in 50% of patients. Post ICU discharge, the indication of 41% of patients' PM was unknown by the non-ICU care team or incorrect. Medical ICU patients or those transferred to an outside facility were more likely remain on PM at hospital discharge.

CONCLUSION

PM are frequently continued during transitions of care and often without knowledge of the initial indication. Future studies should establish effective PM stewardship methods.

Repurposing Valproate, Enteral Clonidine, and Phenobarbital for Comfort in Adult ICU Patients: A Literature Review with Practical Considerations

Provision of adequate sedation is a fundamental part of caring for critically ill patients. Propofol, dexmedetomidine, and benzodiazepines are the most commonly administered sedative medications for adult patients in the intensive care unit (ICU). These agents are limited by adverse effects, need for a monitored environment for safe administration, and lack of universal effectiveness. Increased interest has recently been expressed about repurposing older pharmacologic agents for patient comfort in the ICU. Valproate, enteral clonidine, and phenobarbital are three agents with increasing evidence supporting their use. Potential benefits associated with their utilization are cost minimization and safe administration after transition out of the ICU. This literature review describes the historical context, pharmacologic characteristics, supportive data, and practical considerations associated with the administration of these agents for comfort in critically ill adult patients.

Cefepime-induced neurotoxicity: a systematic review

BACKGROUND

Cefepime is a widely used antibiotic with neurotoxicity attributed to its ability to cross the blood-brain barrier and exhibit concentration-dependent ϒ-aminobutyric acid (GABA) antagonism. Neurotoxic symptoms include depressed consciousness, encephalopathy, aphasia, myoclonus, seizures, and coma. Data suggest that up to 15% of ICU patients treated with cefepime may experience these adverse effects. Risk factors include renal dysfunction, excessive dosing, preexisting brain injury, and elevated serum cefepime concentrations. We aimed to characterize the clinical course of cefepime neurotoxicity and response to interventions.

METHODS

A librarian-assisted search identified publications describing cefepime-associated neurotoxicity from January 1980 to February 2016 using the CINAHL and MEDLINE databases. Search terms included cefepime, neurotoxicity, encephalopathy, seizures, delirium, coma, non-convulsive status epilepticus, myoclonus, confusion, aphasia, agitation, and death. Two reviewers independently assessed identified articles for eligibility and used the Preferred Reporting Items for Systematic review and Meta-Analysis Protocols (PRISMA-P) for data reporting.

RESULTS

Of the 123 citations identified, 37 (representing 135 patient cases) were included. Patients had a median age of 69 years, commonly had renal dysfunction (80%) and required intensive care (81% of patients with a reported location). All patients exhibited altered mental status, with reduced consciousness (47%), myoclonus (42%), and confusion (42%) being the most common symptoms. All 98 patients (73% of cohort) with electroencephalography had abnormalities, including non-convulsive status epilepticus (25%), myoclonic status epilepticus (7%), triphasic waves (40%), and focal sharp waves (39%). As per Food and Drug Administration (FDA)-approved dosing guidance, 48% of patients were overdosed; however, 26% experienced neurotoxicity despite appropriate dosing. Median cefepime serum and cerebrospinal fluid (CSF) concentrations were 45 mg/L (n = 21) and 13 mg/L (n = 4), respectively. Symptom improvement occurred in 89% of patients, and 87% survived to hospital discharge. The median delay from starting the drug to symptom onset was 4 days, and resolution occurred a median of 2 days after the intervention, which included cefepime discontinuation, antiepileptic administration, or hemodialysis.

CONCLUSIONS

Cefepime-induced neurotoxicity is challenging to recognize in the critically ill due to widely varying symptoms that are common in ICU patients. This adverse reaction can occur despite appropriate dosing, usually resolves with drug interruption, but may require additional interventions such as antiepileptic drug administration or dialysis.

Valproate Protein Binding Is Highly Variable in ICU Patients and Not Predicted by Total Serum Concentrations: A Case Series and Literature Review

STUDY OBJECTIVE

The free fraction of valproate (the pharmacologically active moiety, normally 5-10%) may vary significantly in critically ill patients, but this topic is understudied, with only four prior intensive care unit (ICU) case reports. The objective of this study was to evaluate the range of valproate plasma protein binding in ICU patients.

DESIGN

Observational study of consecutive ICU patients.

SETTING

Neurocritical and medical critical care services in a nonuniversity academic medical center.

PATIENTS

Consecutive ICU patients treated with valproate with serum albumin less than 4 g/dl.

MEASUREMENTS AND MAIN RESULTS

Simultaneous total and free trough serum valproate concentrations were measured as were serum creatinine, blood urea nitrogen, albumin, platelets, and transaminase values. The reference concentration range was 50-125 mg/L (total) and 5-17 mg/L (free). Valproate concentrations were categorized as within reference range, low, or high, and as concordant if both concentrations were in the same category. Data are reported as median (interquartile range). Fifteen patients (nine men) were evaluated. The median age was 63 (34-70) years. The valproate dose was 3 g/day (35 mg/kg/day). No patient had a valproate free fraction of 5-10%; the median was 48%, and the range was 15-89%. Total and free concentrations showed poor correlation (0.43) and were concordant in only two patients (both in the reference range). Free valproate concentration was poorly predicted by an equation correcting for albumin (r = 0.45). Suspected adverse drug events occurred in 10 patients: hyperammonemia in 7 of 12 tested (58%), elevated transaminases in 2 of 15 (13%), and thrombocytopenia in 5 of 15 (33%).

CONCLUSIONS

Protein binding of valproate was highly inconsistent in this cohort of ICU patients, and total valproate concentrations did not predict free concentrations, even when correcting for albumin. Additional research to define best practice for dosing and monitoring valproate and the relationship between free valproate concentrations and clinical or adverse effects in ICU patients is needed.

The Evolving Paradigm of Individualized Postresuscitation Care After Cardiac Arrest

The postresuscitation period after a cardiac arrest is characterized by a wide range of physiological derangements. Variations between patients include preexisting medical problems, the underlying cause of the cardiac arrest, presence or absence of hemodynamic and circulatory instability, severity of the ischemia-reperfusion injury, and resuscitation-related injuries such as pulmonary aspiration and rib or sternal fractures. Although protocols can be applied to many elements of postresuscitation care, the widely disparate clinical condition of cardiac arrest survivors requires an individualized approach that stratifies patients according to their clinical profile and targets specific treatments to patients most likely to benefit. This article describes such an individualized approach, provides a practical framework for evaluation and triage at the bedside, and reviews concerns specific to all members of the interprofessional postresuscitation care team.

Valproate for agitation in critically ill patients: A retrospective study

PURPOSE

The purpose was to describe the use of valproate therapy for agitation in critically ill patients, examine its safety, and describe its relationship with agitation and delirium.

MATERIALS AND METHODS

This retrospective cohort study evaluated critically ill adults treated with valproate for agitation from December 2012 through February 2015. Information on valproate prescribing practices and safety was collected. Incidence of agitation, delirium, and concomitant psychoactive medication use was compared between valproate day 1 and valproate day 3. Concomitant psychoactive medication use was analyzed using mixed models.

RESULTS

Fifty-three patients were evaluated. The median day of valproate therapy initiation was ICU day 7, and it was continued for a median of 7 days. The median maintenance dose was 1500 mg/d (23 mg/kg/d). The incidence of agitation (96% vs 61%, P < .0001) and delirium (68% vs 49%, P = .012) significantly decreased by valproate day 3. Treatment with opioids (77% vs 65%, P = .02) and dexmedetomidine (47% vs 24%, P = .004) also decreased. In mixed models analyses, valproate therapy was associated with reduced fentanyl equivalents (-185 μg/d, P = .0003) and lorazepam equivalents (-2.1 mg/d, P = .0004). Hyperammonemia (19%) and thrombocytopenia (13%) were the most commonly observed adverse effects.

CONCLUSIONS

Valproate therapy was associated with a reduction in agitation, delirium, and concomitant psychoactive medication use within 48 hours of initiation.

Transition from dexmedetomidine to enteral clonidine for ICU sedation: an observational pilot study

INTRODUCTION

Enteral clonidine represents a potentially less costly alternative to dexmedetomidine for sedation in intensive care unit (ICU) patients. This study describes our practice of transitioning selected adult ICU patients from dexmedetomidine to clonidine with a focus on efficacy, safety, and drug acquisition costs.

METHODS

We conducted a single-center prospective observational pilot study from January through March 2014. Consecutive patients 18 years and older treated with dexmedetomidine and transitioned to clonidine were followed. The transition was assessed in five phases: dexmedetomidine maintenance, transition, clonidine maintenance, clonidine taper, and post clonidine. Efficacy data included any occurrence of significant pain, excessive agitation or oversedation, delirium, and need for ancillary psychoactive medications. Safety data included any occurrence of bradycardia, hypotension, new second- or third-degree atrioventricular node blockade, and clonidine withdrawal syndrome. Drug acquisition cost avoidances were estimated using average wholesale price.

RESULTS

Twenty patients were evaluated. Fifteen (75%) were successfully transitioned from dexmedetomidine within 48 hours of starting clonidine. The initial and maintenance clonidine regimens were 0.3 mg every 6 hours. Clonidine was the sole α2A -receptor agonist administered for 45 hours while in the ICU and for 54 hours outside the ICU. Fentanyl requirements were lower when clonidine was administered as the sole α2A -receptor agonist as compared to dexmedetomidine alone (387 vs. 891 μg/day, p = 0.03). Otherwise, there were no statistically significant differences in efficacy data during the dexmedetomidine and clonidine maintenance phases. No statistically significant differences in safety data were observed. Clonidine withdrawal syndrome criteria were met in one patient. The potential drug acquisition cost avoidance was $819-$2338 per patient during the 3-month study.

CONCLUSIONS

Transitioning from dexmedetomidine to clonidine may be an efficacious, safe, and less costly method of maintaining α2A -receptor agonist therapy in critically ill adults; these results warrant confirmation in expanded studies.

Implementation of the systems approach to improve a pharmacist-managed vancomycin dosing service

PURPOSE

Quality improvements achieved by applying the systems approach to assess the clinical effectiveness, operational efficiency, and financial feasibility of a pharmacist-managed vancomycin dosing service are described.

SUMMARY

Faced with increased patient volumes and resource demands, the pharmacy department at Tufts Medical Center conducted an evaluation of its adult inpatient vancomycin dosing service using the systems approach, which emphasizes multidisciplinary assessment of system inputs, processes, and outcomes and consensus-building methods to identify needed changes and recommended action steps. A multidisciplinary committee composed of representatives of the medical center's pharmacy, internal medicine, infectious diseases, nursing, phlebotomy, and clinical laboratory services was assembled; in a series of three moderated monthly sessions, committee members deliberated and ultimately reached consensus on a list of action items. Relative to a concurrent intradepartmental assessment of the vancomycin dosing service based solely on pharmacist feedback, the systems approach identified a greater number and wider array of needed improvements in key program areas. Quality improvements implemented as a direct result of the systems-based analysis included a policy change authorizing pharmacists to order serum vancomycin determinations without physician cosignature and inclusion of a vancomycin dosing algorithm in the institutional antibiotic dosing guide. Future changes based on deliverable action items will result in a structured process to help direct program resources toward the patients most in need of pharmacist-managed vancomycin dosing services.

CONCLUSION

The systems approach allowed for a comprehensive multidisciplinary evaluation of the service, as indicated by the identification of process improvements not identified by the department of pharmacy alone.

Prophylactic antibiotics are associated with a lower incidence of pneumonia in cardiac arrest survivors treated with targeted temperature management

INTRODUCTION

Prophylactic antibiotics (PRO) reduce the incidence of early-onset pneumonia in comatose patients with structural brain injury, but have not been examined in cardiac arrest survivors undergoing targeted temperature management (TTM). We investigated the effect of PRO on the development of pneumonia in that population.

METHODS

We conducted a retrospective cohort study comparing patients treated with PRO to those not receiving PRO (no-PRO) using Northern Hypothermia Network registry data. Cardiac arrest survivors ≥ 18 years of age with a GCS<8 at hospital admission and treated with TTM at 32-34 °C were enrolled in the registry. Differences were analyzed in univariate analyses and with logistic regression models to evaluate independent associations of clinical factors with incidence of pneumonia and good functional outcome.

RESULTS

416 of 1240 patients (33.5%) received PRO. Groups were similar in age, gender, arrest location, initial rhythm, and time from collapse to return of spontaneous circulation. PRO patients had less pneumonia (12.6% vs. 54.9%, p < 0.001) and less sepsis (1.2 vs. 5.7%, p < 0.001) compared to no-PRO patients. ICU length of stay (98 vs. 100 h, p = 0.2) and incidence of a good functional outcome (41.1 vs. 36.6%, p = 0.19) were similar between groups. Backwards stepwise logistic regression demonstrated PRO were independently associated with a lower incidence of pneumonia (OR 0.09, 95% 0.06-0.14, p < 0.001) and a similar incidence of good functional outcome.

CONCLUSIONS

Prophylactic antibiotics were associated with a reduced incidence of pneumonia but a similar rate of good functional outcome.

Serotonin syndrome following methylene blue administration during cardiothoracic surgery

INTRODUCTION

Despite its favorable safety profile, there have been reports of methylene blue-induced encephalopathy and serotonin syndrome in patients undergoing parathyroidectomy. We report a case of serotonin syndrome following methylene blue administration in a cardiothoracic surgery patient.

CASE REPORT

A 59-year-old woman taking preoperative venlafaxine and trazodone was given a single dose of 2 mg/kg methylene blue (167 mg) during a planned coronary artery bypass and mitral valve repair. Postoperatively, she was febrile to 38.7°C and developed full-body tremors, rhythmic twitching of the perioral muscles, slow conjugate roving eye movements, and spontaneous movements of the upper extremities. Electroencephalography revealed generalized diffuse slowing consistent with toxic encephalopathy, and a computed tomography scan showed no acute process. The patient's symptoms were most consistent with a methylene blue-induced serotonin syndrome. Her motor symptoms resolved within 48 hours and she was eventually discharged home.

DISCUSSION

Only 2 cases of methylene blue-induced serotonin syndrome during cardiothoracic surgery have been described in the literature, with this report representing the third case. Methylene blue and its metabolite, azure B, are potent, reversible inhibitors of monoamine oxidase A which is responsible for serotonin metabolism. Concomitant administration of methylene blue with serotonin-modulating agents may precipitate serotonin syndrome.

Tremors and agitation following low-dose intravenous hydromorphone administration in a patient with kidney dysfunction

OBJECTIVE

To report a case of tremors and agitation associated with the administration of low doses of intravenous hydromorphone in a patient with acute kidney injury in the setting of chronic kidney disease.

CASE SUMMARY

A 91-year-old man was admitted for a left intertrochanteric hip fracture. On hospital days 1 and 2, the patient received hydromorphone 1 mg intravenously for pain. By hospital day 3, the patient had received a total of 3.5 mg of hydromorphone. He then became tremulous and agitated, which worsened as the dose was increased. During hospital day 4, the hydromorphone dosage was increased to 0.5 mg intravenously every 4 hours for what was perceived to be inadequate pain control, manifesting as tremors and agitation. On hospital day 5, hydromorphone, now considered a potential cause of the tremors and agitation, was discontinued. The total amount of hydromorphone administered was 8 mg over 5 days. By hospital day 6, the tremors and agitation had decreased in severity and had resolved by hospital day 7.

DISCUSSION

Previous reports suggest that hydromorphone-induced neurotoxicity is more likely to occur following high doses over extended periods, especially in patients with kidney dysfunction. There is a paucity of evidence suggesting that neurotoxicity can occur following low doses for short periods of time. Morphine-3-glucuronide has neuroexcitatory properties including myoclonus, allodynia, agitation, or tremors. Structural similarities between morphine-3-glucuronide and hydromorphone-3-glucuronide suggest that neuroexcitatory effects with hydromorphone are feasible. The Naranjo probability scale indicated that hydromorphone-induced tremors were possible. Our case is distinct because the patient received low doses of hydromorphone over a short period.

CONCLUSIONS

Neurotoxicity can occur in patients with kidney dysfunction while they receive low doses of intravenous hydromorphone over short periods. Diligent monitoring and reporting of such effects are necessary to better understand risk factors and a mechanism.

The influence of vesical distension on the urethral resistance to flow: a possible role for prostaglandins?

The possible role of prostaglandins in the mediation and/or modulation of the urethral response to vesical distension was investigated in female dogs. Three criteria for the possible involvement of these mediators have been investigated. Indomethacin could block the reduction of urethral resistance observed during vesical distension. Intra-arterial infusion of exogenous prostaglandin E2 resulted in a dose-dependent reduction in the urethral resistance to flow. Moreover, a significant release of prostaglandin E2 in the venous blood during the course of vesical distension could be demonstrated. The functional significance, mechanisms of release and mode of action of these highly active lipids are discussed.

Lithium-angiotensin interaction in rat neurohypophysis

The effects of various concentrations of lithium upon basal and angiotensin-stimulated cyclic AMP accumulation were studied in isolated rat neurohypophysis. High doses of lithium diminished significantly the spontaneous accumulation of the nucleotide. This effect was not influenced by pre-incubation. Angiotensin-stimulated accumulation was inhibited by lithium at a dose which did not interfere with the basal accumulation of cyclic AMP. The possible physiological significance and mechanism of action are discussed.

The influence of vesical distension on urethral resistance to flow: the collecting phase

Using female dogs, changes in the urethral pressure profile in response to vesical distension were studied. It was noted that during the collecting phase there was an increase in the amplitude of the profile tracing. These experiments revealed that this increase is not mediated through an autonomic reflex and does not reflect a significant enhancement of alpha-adrenergic activity. These changes are mainly due to increased tension of the urethral muscle, secondly to detrusor stretch.

The influence of vesical distension on urethral resistance to flow: the expulsion phase

The influence of vesical distension of the urethral pressure profile was studied in female dogs, using a model in which the bladder and urethra were separated. There was a reduction in the urethral resistance involving its smooth and striated muscle components. This reduction was completely blocked by ganglion blocking agents. Atropine did not influence these changes. Propranolol could only partially block this reflex. The other possible mechanisms that could be involved were discussed.

Structural requirements for angiotensin analogues to accumulate cyclic AMP and release vasopressin from the incubated rat neurohypophysis

1. Angiotensin I, a decapeptide, stimulated the accumulation of cyclic 3',5'-AMP (cyclic AMP) and the release of vasopressin from incubated rat neurohypophyses. 2. Various octapeptides related to angiotensin II were capable of producing similar neurohypophyseal effects. 3. Longer incubation periods were needed with peptides having alterations or omission (e.g. heptapeptide 2-8) at position 1 of the parent molecule to evoke similar effects to those of angiotensin II. 4. Our results suggest strongly that physiological doses of angiotensin-related molecules stimulate the secretion of vasopressin through cyclic AMP, and that the neurohypophyseal receptor responsible for these effects is similar to that involved in their peripheral actions.

Stimulation by angiotensin II of the release of vasopressin from incubated rat neurohypophyses---possible involvement of cyclic AMP

1. Calcium did not influence the spontaneous release of vasopressin from rat neurohypophyses in vitro when used in concentrations of 0.05, 0.5 and 2.8 mM in the bathing medium. 2. Stimulation of the basal output of vasopressin by angiotensin II (1 X 10(-9) M) required at least 0.5 mM calcium in the medium. 3. Angiotensin II stimulated the release of vasopressin within 2.5 min of incubation, maximal release was observed after 10 min. 4. Angiotensin II rapidly promoted the accumulation of tissue cyclic AMP; maximal accumulation was observed after 5 min of incubation. 5. Theophylline and dibutyryl cyclic AMP produced varying degree of stimulation of the release of vasopressin. 6. Increases in vasopressin secretion and in the accumulation of cyclic AMP were always present when neurohypophyses were exposed to optiman concentrations of angiotensin II. The results presented suggested that cyclic AMP may be an intermediate step for the release of vasopressin by endogenous angiotensin II.