Prolonged Hourly Neurologic Examinations are Associated with Increased Delirium and No Discernible Benefit in Mild/Moderate Geriatric Traumatic Brain Injury

BACKGROUND

Serial neurologic examinations (NE) are routinely recommended in the ICU within the first 24 hours following a TBI. There are currently no widely accepted guidelines for the frequency of NE. Disruptions to the sleep-wake cycles increase the delirium rate. We aimed to evaluate whether there is a correlation between prolonged Q1-NE and development of delirium and to determine if this practice reduces the likelihood of missing the detection of a process requiring emergent intervention.

METHODS

Retrospective analysis of patients with mild/moderate TBI, admitted to the ICU with serial-NE. Cohorts were stratified by the duration of exposure to Q1-NE, into Prolonged(≥24 h) and Not Prolonged(<24 h). Our primary outcomes of interest was delirium, evaluated using the Confusion Assessment Method (CAM-ICU), radiological progression from baseline images, neurological deterioration (focal neurological deficit, abnormal pupillary exam, or GCS decrease >2), and neurosurgical procedures.

RESULTS

A total of 522 patients were included. No significant differences were found in demographics. Patients in the Prolonged Q1-NE group (26.1%) had higher ISS with similar AIS Head, and significantly higher delirium rate [59% vs 35%, p < .001], and a longer Hospital/ICU length of stay when compared to the Not Prolonged Q1-NE group. No neurosurgical interventions were found to be performed emergently as a result of findings on NE. Multivariate analysis demonstrated that Prolonged Q1-NE was the only independent risk factor associated with a 2.5-fold increase in delirium rate. The Number Needed to Harm for prolonged Q1-NE was 4.

CONCLUSIONS

Geriatric patients with mild/moderate TBI exposed to Q1-NE for periods longer than 24 h had nearly a 3-fold increase in ICU-Delirium rate. One out of five patients exposed to prolonged Q1-NE is harmed by the development of delirium. No patients were found to directly benefit as a result of more frequent neurological examinations.

B cells mediate lung ischemia/reperfusion injury by recruiting classical monocytes via synergistic B cell receptor/TLR4 signaling

Ischemia/reperfusion injury-mediated (IRI-mediated) primary graft dysfunction (PGD) adversely affects both short- and long-term outcomes after lung transplantation, a procedure that remains the only treatment option for patients suffering from end-stage respiratory failure. While B cells are known to regulate adaptive immune responses, their role in lung IRI is not well understood. Here, we demonstrated by intravital imaging that B cells are rapidly recruited to injured lungs, where they extravasate into the parenchyma. Using hilar clamping and transplant models, we observed that lung-infiltrating B cells produce the monocyte chemokine CCL7 in a TLR4-TRIF-dependent fashion, a critical step contributing to classical monocyte (CM) recruitment and subsequent neutrophil extravasation, resulting in worse lung function. We found that synergistic BCR-TLR4 activation on B cells is required for the recruitment of CMs to the injured lung. Finally, we corroborated our findings in reperfused human lungs, in which we observed a correlation between B cell infiltration and CM recruitment after transplantation. This study describes a role for B cells as critical orchestrators of lung IRI. As B cells can be depleted with currently available agents, our study provides a rationale for clinical trials investigating B cell-targeting therapies.