Letter to Editor

Acute brain injuries are commonly encountered in the intensive care unit. Alterations in cerebrovascular physiology triggered by the initial insult can lead to neurological worsening, further brain injury, and poor outcomes. Robust methods for assessing cerebrovascular physiology continuously at the bedside are limited. In this review, we aim to assess the potential of near-infrared spectroscopy (NIRS) as a bedside tool to monitor cerebrovascular physiology in critically ill patients with acute brain injury as well as those who are at high risk for developing brain injury. We first review basic principles of cerebral blood flow regulation and how these are altered after brain injury. We then discuss the potential role for NIRS in different acute brain injuries. We pay specific attention to the potential for NIRS to (1)identify new brain injuries and clinical worsening, (2)non-invasively measure intracranial pressure (ICP) and cerebral autoregulation, and (3)identify optimal blood pressure (BP) targets that may improve patient outcomes. A growing body of work supports the use of NIRS in the care of brain injured patients. NIRS is routinely used during cardiac surgeries to identify acute neurologic events, and there is some evidence that treatment algorithms using cerebral oximetry may result in improved outcomes. In acute brain injury, NIRS can be used to measure autoregulation to identify an "optimum" BP where autoregulation status is best preserved. Finally, NIRS has been utilized to identify oximetry thresholds that correlate with poor outcome as well as identify new focal intracranial hemorrhages. NIRS is emerging as a tool that can non-invasively measure brain function in critically ill patients. Future work will be aimed at technical refinements to improve diagnostic accuracy, as well as larger scale clinical trials that can establish a definitive impact on patient outcomes.

To the Editor: We were pleased to read the publication “Evolution and Impact of the Brain Trauma Foundation Guidelines” and are proud to be among the many people over the years who have contributed to the important work of the Brain Trauma Foundation (BTF).1 Thank you for bringing this history together. We are writing with one clarification and one comment. Our clarification is about the Guidelines for the Acute Medical Management of Severe Traumatic Brain Injury in Infants, Children, and Adolescents, first edition.2 The first edition was an independent project and not supported by the BTF. The administrative machinery to carry out the extensive, 3-year project was provided by the Evidence-based Practice Center located at Oregon Health & Science University. Investigators, authors, and administrative staff were volunteers; funding for the simultaneous publication in 3 journals was provided by the National Institute of Neurological Disorders and Stroke, and the National Center for Medical Rehabilitation Research of the Eunice Kennedy Shriver National Institute of Child Health and Human Development. The Oregon Health & Science University team subsequently partnered with the BTF to generate further editions of the pediatric, adult, and prehospital guidelines.3-8 Our comment is in reference to the statement from the publication regarding the third edition of the pediatric guidelines: “The treatment algorithm which accompanies the third edition was conceived independent of other projects such as the Seattle International Severe Traumatic Brain Injury Consensus Conference (SIBICC) algorithms. Of interest, the panelists who have participated in the creation of the pediatric guidelines largely differ from those of the adult guidelines. Because of this, differences between the recommendations for adult and pediatric patients inspire reflection as to whether they reflect a true difference in adult and pediatric best care or whether they reflect a distinct interpretation of similar literature.” We find this reflection to be somewhat paradoxical to the direction of the field of neurocritical care in the treatment of severe traumatic brain injury (TBI). It is unlikely that best care for a 3-month-old victim of abusive head trauma would be equally well-directed by an algorithm generated from studies that included elderly adults who suffer TBI, or even young adults, for that matter. It is surprising in this era where in both pediatric and adult TBI we seek to endophenotype to direct precision care. For example, a recent work by Woods et al9 questions whether an intracranial pressure threshold of 15 mm Hg might be more appropriate in pediatrics at the same time that the adult threshold has risen to 22 mm Hg.7 Propofol use in adults but not children is another key difference that is impossible to ignore and well beyond interpretation.5 Similarly, given the concerns over apoptosis in the developing brain, optimal medications for sedation have not been well elucidated.10 Finally, issues of sex differences across ages have not been studied. We believe that we should be redoubling our efforts to better understand and further enhance precision care within the age epochs of both pediatric and adult neurocritical care in severe TBI, learning from the studies across the entire field and continuing the dialog. Thank you for the opportunity to clarify and contribute to this dialog.

Alcohol withdrawal syndrome (AWS) can range from mild jittery movements, nausea, sweating to more severe symptoms such as seizure and death. Severe AWS can worsen cognitive function, increase hospital length of stay, and in-hospital mortality and morbidity. Due to a lack of reliable history of present illness in many patients with neurological injury as well as similarities in clinical presentation of AWS and some commonly encountered neurological syndromes, the true incidence of AWS in neurocritical care patients remains unknown. This review discusses challenges in the assessment and treatment of AWS in patients with neurological injury, including the utility of different scoring systems such as the Clinical Institute Withdrawal Assessment and the Minnesota Detoxification Scale as well as the reliability of admission alcohol levels in predicting AWS. Treatment strategies such as symptom-based versus fixed dose benzodiazepine therapy and alternative agents such as baclofen, carbamazepine, dexmedetomidine, gabapentin, phenobarbital, ketamine, propofol, and valproic acid are also discussed. Finally, a treatment algorithm considering the neurocritical care patient is proposed to help guide therapy in this setting.

Current advances in clinical and translational research bring into sharper focus the importance of epidemiologic, neurobiologic and pathophysiologic factors that contribute to neonatal seizure occurrence, and potential consequences for subsequent neurologic deficits. Diagnostic and therapeutic algorithms must integrate prenatal, peripartum and postnatal contributions to neonatal seizures with or without the expression of neonatal encephalopathy. Neonatal seizure classifications must consider time-dependent vulnerabilities to injury from different etiologies in specific brain regions as a function of gestational maturity. The design of therapeutic protocols for neuroprotection must consequently consider both prenatal and postnatal strategies for prevention as well as rescue and repair. Neonatal neurointensive care programs need to integrate these protocols into the care paths of preterm and/or full-term neonates who express neonatal seizures in the context of acute and/or chronic brain disorders. A newborn with seizures represents a complex phenotype of past, present and future risks for brain injury.

Background: Bedside nurses have been recognized as potential antibiotic stewards; however, data on effective ways that nurses can contribute to stewardship activities in acute-care hospitals are scarce. Methods: A nurse-driven urine culture intervention to improve urine culture ordering practices was implemented in a medicine and a neurocritical care unit (NCCU) at The Johns Hopkins Hospital. Bedside nurses implemented an algorithm (Fig. 1) developed by the antibiotic stewardship program (ASP) to review the appropriateness of urine culture and to guide discussions with ordering providers regarding unnecessary urine cultures. Nurses received in-person training by an ASP physician champion on how to use the algorithm and education on the definition and indications for evaluation for asymptomatic bacteriuria and urinary tract infections. The ASP physician periodically visited the units to address concerns and questions. In both units, a nurse champion was identified to serve as liaison between the ASP and bedside nurses, and physician support was obtained before the intervention. The pre- and postintervention periods for the medicine unit were September 2017–August 2018 and September 2018–August 2019, respectively. For the NCCU, these periods were September 2018–February 2019 and March 2019–September 2019, respectively. Trends in urine cultures per 100 patient days (PD) were examined with statistical process charts and compared before and after the intervention using a standard incident ratio (IRR) and Poisson regression. Results: In total, 327 urine cultures were collected in the medicine unit and 293 in the NCCU over the study period. Although the intervention led to a significant 34% reduction in the rate of urine cultures on the medicine unit (from 2.3 to 1.5 cultures/100 PD; IRR, 0.66; 95% CI, 0.50–0.87; P < .01), the number of urine cultures remained without a significant change in the NCCU (from 4.5 to 3.7 cultures/100 PD; IRR, 0.89; 95% CI, 0.65–1.22; P = .48) (Fig. 2). Conclusions: Algorithm-based, nurse-driven review of urine culture indications reduced urine cultures on a medicine unit but not in a neurosciences ICU. Success on the medicine unit may have been driven by highly engaged nurse and physician champions and by patients being able to respond questions about symptoms. The following factors might have impacted results on NCCU: presence of conflicting protocols (eg, panculturing patients every 48 hours per a hypothermia protocol), unit tradition (eg, obtaining cultures to assess treatment response), perception of greater risk benefit in NCCU patients, and unit dynamics (open unit with other primary services placing orders for patients). Unit and team dynamics can affect effective implementation of antimicrobial stewardship interventions by nurses.Funding: NoneDisclosures: None