Modulation of the allosteric and vasoregulatory arms of erythrocytic oxygen transport.

Efficient distribution of oxygen (O2) to the tissues in mammals depends on the evolved ability of red blood cell (RBC) hemoglobin (Hb) to sense not only O2 levels, but metabolic cues such as pH, PCO2, and organic phosphates, and then dispense or take up oxygen accordingly. O2 delivery is the product of not only oxygen release from RBCs, but also blood flow, which itself is also governed by vasoactive molecular mediators exported by RBCs. These vascular signals, including ATP and S-nitrosothiols (SNOs) are produced and exported as a function of the oxygen and metabolic milieu, and then fine-tune peripheral metabolism through context-sensitive vasoregulation. Emerging and repurposed RBC-oriented therapeutics can modulate either or both of these allosteric and vasoregulatory activities, with a single molecule or other intervention influencing both arms of O2 transport in some cases. For example, organic phosphate repletion of stored RBCs boosts the negative allosteric effector 2,3 biphosphoglycerate (BPG) as well as the anti-adhesive molecule ATP. In sickle cell disease, aromatic aldehydes such as voxelotor can disfavor sickling by increasing O2 affinity, and in newer generations, these molecules have been coupled to vasoactive nitric oxide (NO)-releasing adducts. Activation of RBC pyruvate kinase also promotes a left shift in oxygen binding by consuming and lowering BPG, while increasing the ATP available for cell health and export on demand. Further translational and clinical investigation of these novel allosteric and/or vasoregulatory approaches to modulating O2 transport are expected to yield new insights and improve the ability to correct or compensate for anemia and other O2 delivery deficits.

Exploring the feasibility of pupillometry training and perceptions of potential use for intracranial pressure monitoring in Uganda: A mixed methods study.

INTRODUCTION: Traumatic brain injury (TBI) accounts for the majority of Uganda's neurosurgical disease burden; however, invasive intracranial pressure (ICP) monitoring is infrequently used. Noninvasive monitoring could change the care of patients in such a setting through quick detection of elevated ICP. PURPOSE: Given the novelty of pupillometry in Uganda, this mixed methods study assessed the feasibility of pupillometry for noninvasive ICP monitoring for patients with TBI. METHODS: Twenty-two healthcare workers in Kampala, Uganda received education on pupillometry, practiced using the device on healthy volunteers, and completed interviews discussing pupillometry and its implementation. Interviews were assessed with qualitative analysis, while quantitative analysis evaluated learning time, measurement time, and accuracy of measurements by participants compared to a trainer's measurements. RESULTS: Most participants (79%) reported a positive perception of pupillometry. Participants described the value of pupillometry in the care of patients during examination, monitoring, and intervention delivery. Commonly discussed concerns included pupillometry's cost, understanding, and maintenance needs. Perceived implementation challenges included device availability and contraindications for use. Participants suggested offering continued education and engaging hospital leadership as implementation strategies. During training, the average learning time was 13.5 minutes (IQR 3.5), and the measurement time was 50.6 seconds (IQR 11.8). Paired t-tests to evaluate accuracy showed no statistically significant difference in comparison measurements. CONCLUSION: Pupillometry was considered acceptable for noninvasive ICP monitoring of patients with TBI, and pupillometer use was shown to be feasible during training. However, key concerns would need to be addressed during implementation to aid device utilization.

A Mixed-Methods Assessment of the Feasibility of Conducting Neurosurgical Clinical Research in Uganda.

BACKGROUND: Clinical research is necessary to evaluate neurosurgical interventions, yet clinical trials are conducted less frequently in low- and middle-income countries. Because specific barriers, facilitating factors, and strategies for neurosurgical clinical research in Uganda have not been previously identified, this study evaluated neurosurgical providers' perspectives on clinical research and documentation patterns of neurosurgical variables at Mulago National Referral Hospital. METHODS: Retrospective review of 166 neurosurgical patient charts assessed the frequency of documentation of key variables. Twenty-two providers working in neurosurgery participated in 6 focus group discussions with qualitative analysis utilizing the framework method. RESULTS: Chart review showed that primary diagnosis (99.4%), pupil light response (97.6%), and computed tomography scan results (93.3%) were documented for most patients. Cranial nerve exam (61.5%), pupil size (69.9%), and time to neurosurgical intervention (45%) were documented less frequently. On average, Glasgow Coma Scale was documented for 86.6% of days hospitalized, while vital signs were documented for 12.3%. In most focus group discussions, participants identified follow-up, financing, recruitment, time, approval, and sociocultural factors as research barriers. Participants described how the current health workforce facilitates successful research. To improve research capacity, suggested strategies focused on research networks, data collection, leadership, participant recruitment, infrastructure, and implementation. CONCLUSIONS: At Mulago National Referral Hospital, there was variability in the frequency of documentation of neurosurgical variables, which may impact data collection for future studies. While multiple barriers were identified, sociocultural, financing, and time barriers greatly impacted neurosurgical clinical research. Despite that, identified facilitating factors and strategies could be utilized to support neurosurgical research capacity growth.