Bedside detection of intracranial midline shift using portable magnetic resonance imaging

Neuroimaging is crucial for assessing mass effect in brain-injured patients. Transport to an imaging suite, however, is challenging for critically ill patients. We evaluated the use of a low magnetic field, portable MRI (pMRI) for assessing midline shift (MLS). In this observational study, 0.064 T pMRI exams were performed on stroke patients admitted to the neuroscience intensive care unit at Yale New Haven Hospital. Dichotomous (present or absent) and continuous MLS measurements were obtained on pMRI exams and locally available and accessible standard-of-care imaging exams (CT or MRI). We evaluated the agreement between pMRI and standard-of-care measurements. Additionally, we assessed the relationship between pMRI-based MLS and functional outcome (modified Rankin Scale). A total of 102 patients were included in the final study (48 ischemic stroke; 54 intracranial hemorrhage). There was significant concordance between pMRI and standard-of-care measurements (dichotomous, κ = 0.87; continuous, ICC = 0.94). Low-field pMRI identified MLS with a sensitivity of 0.93 and specificity of 0.96. Moreover, pMRI MLS assessments predicted poor clinical outcome at discharge (dichotomous: adjusted OR 7.98, 95% CI 2.07–40.04, p = 0.005; continuous: adjusted OR 1.59, 95% CI 1.11–2.49, p = 0.021). Low-field pMRI may serve as a valuable bedside tool for detecting mass effect.

First-in-clinical application of a time-gated diffuse correlation spectroscopy system at 1064nm using superconducting nanowire single photon detectors

Recently proposed time-gated DCS (TG-DCS) has significant advantages compared to conventional CW-DCS, but it is still in an early stage and clinical capability has yet to be established. The main challenge for TG-DCS is the lower SNR when gating for the deeper travelling late photons. Longer wavelengths, such as 1064nm have a smaller effective attenuation coefficient and a higher power threshold in humans, which significantly increases the SNR. Here, we demonstrate the clinical utility of TG-DCS at 1064 nm in a case study on a patient with severe traumatic brain injury admitted to the neuroscience intensive care unit (NSICU). We showed a significant correlation between TG-DCS early (ρ = 0.67) and late (ρ = 0.76) gated against invasive thermal diffusion flowmetry. We also analyzed TG-DCS at high temporal resolution (50 Hz) to elucidate pulsatile flow data. Overall, this study demonstrates the first clinical translation capability of the TG-DCS system at 1064nm using superconducting nanowire single photon detector.

Neuromuscular Disease in the Neuroscience Intensive Care Unit

Neurologists may meet patients with neuromuscular disease and subsequent respiratory failure in the inpatient setting. Common clinical conditions include Guillain-Barré syndrome (GBS) and myasthenia gravis (MG). Recognition of impending respiratory failure for such patients is of great importance. This chapter describes general features of neuromuscular weakness and neuromuscular respiratory failure. In addition, it reviews the clinically important aspects of GBS, MG, and botulism. Finally, the chapter outlines the clinical symptoms, diagnosis, and treatment of critical illness polyneuropathy, a commonly encountered condition in the medical intensive care unit.

Investigation of Pansusceptible Pseudomonas aeruginosa Meningitis Cases in Patients With External Ventricular Devices

Background: During a 2-month period at an academic medical system, 4 cases of pansusceptible P. aeruginosa (PsA) meningitis were identified among neuroscience intensive care unit (NSICU) patients with an external ventricular device (EVD). Methods: We reviewed microbiology data for the previous 2 years to determine background PsA rates and to identify additional cases of PsA meningitis. A case was defined as the isolation of PsA from a CSF specimen. We convened a multidisciplinary group of stakeholders to review medical records of case patients and to conduct a series of observational rounds. Scalp swab specimens were collected from NSICU patients to detect possible skin colonization. Pulsed-field gel electrophoresis (PFGE) analyses were performed on PsA isolates from the 4 case patients and 5 patients with PsA isolates from other body sites. Results: There was no hospital-wide increase in PsA incidence, and no patient without an EVD had PsA cultured from CSF. Infections occurred, on average, 10 days (range, 6–15 days) after EVD insertion. Cases were geographically dispersed in the NSICU and did not share common staff. None of the PsA isolates were genetically related and all scalp cultures were negative. Observations included multiple opportunities for contact with water sources: sinks in proximity to the head of the bed, storage of supplies next to sinks, reuse of bath basins, and use of dilute peroxide to clean surgical wounds. Multiuse shampoos, conditioners and lotions, not approved for hospital use, were found on the unit. Furthermore, 3 of 4 patients received cefazolin >24 hours after 6 of their 7 neurosurgeries for an average of 4.7 days (range, 0.8–4 days). Care practices were changed to mitigate contact between EVD sites and environmental water sources, and extended cefazolin surgical prophylaxis was discontinued. EVD practices were revised, and clinical teams had their competency confirmed. No additional cases have been identified in the 16 months following these interventions. Conclusions: This cluster of EVD infections was likely caused by patient care practices that resulted in independent introductions of PsA from multiple nonsterile or contaminated water sources. Antibiotic selection of PsA by extended use of cefazolin perioperative prophylaxis may have also contributed. EVD care practices should be designed to limit contact between and EVD insertion sites and nonsterile water sources or potentially contaminated care supplies. To substantiate performance improvement efforts and ensure interinstitutional comparability, a practical, standardized EVD-associated infection surveillance definition is needed.Funding: NoneDisclosures: None

COVID-19 and Decompressive Hemicraniectomy for Acute Ischemic Stroke

Background and Purpose: Young patients with malignant cerebral edema have been shown to benefit from early decompressive hemicraniectomy. The impact of concomitant infection with coronavirus disease 2019 (COVID-19) and how this should weigh in on the decision for surgery is unclear. Methods: We retrospectively reviewed all COVID-19–positive patients admitted to the neuroscience intensive care unit for malignant edema monitoring. Patients with >50% of middle cerebral artery involvement on computed tomography imaging were considered at risk for malignant edema. Results: Seven patients were admitted for monitoring of whom 4 died. Cause of death was related to COVID-19 complications, and these were either seen both very early and several days into the intensive care unit course after the typical window of malignant cerebral swelling. Three cases underwent surgery, and 1 patient died postoperatively from cardiac failure. A good outcome was attained in the other 2 cases. Conclusions: COVID-19–positive patients with large hemispheric stroke can have a good outcome with decompressive hemicraniectomy. A positive test for COVID-19 should not be used in isolation to exclude patients from a potentially lifesaving procedure.