Cerebro-spinal fluid glucose and lactate concentrations changes in response to therapies in patIents with primary brain injury: the START-TRIP study.

INTRODUCTION: Altered levels of cerebrospinal fluid (CSF) glucose and lactate concentrations are associated with poor outcomes in acute brain injury patients. However, no data on changes in such metabolites consequently to therapeutic interventions are available. The aim of the study was to assess CSF glucose-to-lactate ratio (CGLR) changes related to therapies aimed at reducing intracranial pressure (ICP). METHODS: A multicentric prospective cohort study was conducted in 12 intensive care units (ICUs) from September 2017 to March 2022. Adult (> 18 years) patients admitted after an acute brain injury were included if an external ventricular drain (EVD) for intracranial pressure (ICP) monitoring was inserted within 24 h of admission. During the first 48-72 h from admission, CGLR was measured before and 2 h after any intervention aiming to reduce ICP ("intervention"). Patients with normal ICP were also sampled at the same time points and served as the "control" group. RESULTS: A total of 219 patients were included. In the intervention group (n = 115, 53%), ICP significantly decreased and CPP increased. After 2 h from the intervention, CGLR rose in both the intervention and control groups, although the magnitude was higher in the intervention than in the control group (20.2% vs 1.6%; p = 0.001). In a linear regression model adjusted for several confounders, therapies to manage ICP were independently associated with changes in CGLR. There was a weak inverse correlation between changes in ICP and CGRL in the intervention group. CONCLUSIONS: In this study, CGLR significantly changed over time, regardless of the study group. However, these effects were more significant in those patients receiving interventions to reduce ICP.

Detection of cerebral hypoperfusion with a dynamic hyperoxia test using brain oxygenation pressure monitoring.

INTRODUCTION: Brain multimodal monitoring including intracranial pressure (ICP) and brain tissue oxygen pressure (PbtO2) is more accurate than ICP alone in detecting cerebral hypoperfusion after traumatic brain injury (TBI). No data are available for the predictive role of a dynamic hyperoxia test in brain-injured patients from diverse etiology. AIM: To examine the accuracy of ICP, PbtO2 and the oxygen ratio (OxR) in detecting regional cerebral hypoperfusion, assessed using perfusion cerebral computed tomography (CTP) in patients with acute brain injury. METHODS: Single-center study including patients with TBI, subarachnoid hemorrhage (SAH) and intracranial hemorrhage (ICH) undergoing cerebral blood flow (CBF) measurements using CTP, concomitantly to ICP and PbtO2 monitoring. Before CTP, FiO2 was increased directly from baseline to 100% for a period of 20 min under stable conditions to test the PbtO2 catheter, as a standard of care. Cerebral monitoring data were recorded and samples were taken, allowing the measurement of arterial oxygen pressure (PaO2) and PbtO2 at FiO2 100% as well as calculation of OxR (= ΔPbtO2/ΔPaO2). Regional CBF (rCBF) was measured using CTP in the tissue area around intracranial monitoring by an independent radiologist, who was blind to the PbtO2 values. The accuracy of different monitoring tools to predict cerebral hypoperfusion (i.e., CBF < 35 mL/100 g × min) was assessed using area under the receiver-operating characteristic curves (AUCs). RESULTS: Eighty-seven CTPs were performed in 53 patients (median age 52 [41-63] years-TBI, n = 17; SAH, n = 29; ICH, n = 7). Cerebral hypoperfusion was observed in 56 (64%) CTPs: ICP, PbtO2 and OxR were significantly different between CTP with and without hypoperfusion. Also, rCBF was correlated with ICP (r = - 0.27; p = 0.01), PbtO2 (r = 0.36; p < 0.01) and OxR (r = 0.57; p < 0.01). Compared with ICP alone (AUC = 0.65 [95% CI, 0.53-0.76]), monitoring ICP + PbO2 (AUC = 0.78 [0.68-0.87]) or ICP + PbtO2 + OxR (AUC = 0.80 (0.70-0.91) was significantly more accurate in predicting cerebral hypoperfusion. The accuracy was not significantly different among different etiologies of brain injury. CONCLUSIONS: The combination of ICP and PbtO2 monitoring provides a better detection of cerebral hypoperfusion than ICP alone in patients with acute brain injury. The use of dynamic hyperoxia test could not significantly increase the diagnostic accuracy.

Diaphragm Ultrasound: A Valuable Predictor of the Outcome of Extubation. An Observational Pilot Study in Covid-19 Related ARDS.

Introduction: Because both early and delayed weaning are associated with increased mortality, longer stay in the ICU and higher economic costs, performing extubation once the patient can cope with the respiratory load is completely recommended. Ultrasound Sonography (US) is an available bedside tool that allows a rapid assessment and visualization of the different structures involved in spontaneous breath. M-mode ultrasonography can be useful for the assessment of diaphragm kinetics, providing valuable information about diaphragm disfunction. Aim of the Study: The aim of this study is to find a correlation between the value of the acceleration of the diaphragm detected with the US M-mode and the outcome of the weaning. Materials and Methods: We have enrolled 19 patients admitted in our ICU. Each patient underwent the trial with the ultrasound M-mode to assess the acceleration of the diaphragm during the contraction. We have analyzed the results relating them to the outcome of the weaning. Results: While 11 of our patients have had a successful weaning, 8 have failed it, and we can see that the outcome is associated to the values of acceleration. Discussion: Our study has demonstrated that an assessment of the diaphragm function using US could represent a usable and effective technique as the acceleration is related to the force generated by the diaphragm contraction. Conclusions: In conclusion, the acceleration could be a useful parameter to consider when it comes to the prediction of the outcome of the weaning process.

Impaired platelet reactivity in patients with septic shock: a proof-of-concept study.

Coagulation disorders and thrombocytopenia are common in patients with septic shock, but only few studies have focused on platelet variables beyond platelet count. The aim of this study was to evaluate whether platelets reactivity predicts sepsis-induced thrombocytopenia in patients with septic shock. We therefore enrolled consecutive patients with septic shock and platelets count >150*103/µL on the day of the diagnosis. Platelets reactivity tests were performed daily from the diagnosis of septic shock until day five; platelet volume distribution and mean platelet volume were also recorded daily. Sepsis-induced thrombocytopenia was defined as a platelet count <150*103/µL. Thirty patients were included; sepsis-induced thrombocytopenia occurred in 11 (31%) patients. Platelets reactivity and platelet count at day of septic shock diagnosis were not correlated. Patients who experienced thrombocytopenia had lower maximal aggregation at diagnosis than others. Maximal aggregation tests were predictors of thrombocytopenia (AUROC from 0.756 to 0.797, depending on the agonist used). Both platelet volume distribution width and mean platelet volume were predictors of 90-day mortality (AUROC 0.866 and 0.735, respectively). In this pilot study, impaired platelets reactivity was more common in patients who subsequently developed sepsis-induced thrombocytopenia; also, platelet volume distribution width and mean platelet volume were predictors of 90-day mortality.