Autoimmune Hemolytic Anemia and Pulmonary Embolism: An Association to Consider.

Autoimmune hemolytic anemia (AIHA) is increasingly recognized as a strong risk factor for venous thrombosis. However, there are currently no guidelines on thromboembolism prevention and management during AIHA. Here, we describe the case of a patient with AIHA and pulmonary embolism and resume the current knowledge on epidemiology, risk factors, treatment, and pathophysiology of thrombosis during AIHA, as well as new therapeutic perspectives to prevent thrombus formation during AIHA.

[The Internal medicine articles that struck us the most in 2020]. / L'année 2020 mise en perspective par les internistes hospitaliers.

2020 has continued to bring important progress in all areas of internal medicine, impacting our daily practice. From a shift to oral stepdown antibiotics in infectious endocarditis, to new indications for apixaban, SLGT-2 inhibitors and macrolide antibiotics, passing by the catheter-based renal denervation in hypertension, early paracentesis in cirrhosis and new diagnostic criteria in pulmonary embolism, internal medicine journals are full of novelties. Every year, the chief residents of internal medicine at the Swiss University Hospital of Lausanne meet up to share their readings: here is their selection of eleven articles, summarized and commented for you.

L'année 2020 a vu de notables progrès dans tous les domaines de la médecine interne, avec un impact important sur notre pratique quotidienne. Du passage à une antibiothérapie orale dans l'endocardite infectieuse, aux nouvelles indications pour l'apixaban, les inhibiteurs du SGLT2 (sodium-glucose co-transporteur de type 2) et les macrolides en passant par la dénervation rénale dans l'hypertension artérielle, la ponction d'ascite et les changements de critères diagnostiques de l'embolie pulmonaire, les nouveautés abondent dans la littérature. Chaque année, les chefs de clinique du Service de médecine interne du CHUV se réunissent pour partager leurs lectures : voici une sélection de onze articles choisis, revus et commentés pour vous.

Modulation of cerebral ketone metabolism following traumatic brain injury in humans.

Adaptive metabolic response to injury includes the utilization of alternative energy substrates - such as ketone bodies (KB) - to protect the brain against further damage. Here, we examined cerebral ketone metabolism in patients with traumatic brain injury (TBI; n = 34 subjects) monitored with cerebral microdialysis to measure total brain interstitial tissue KB levels (acetoacetate and ß-hydroxybutyrate). Nutrition - from fasting vs. stable nutrition state - was associated with a significant decrease of brain KB (34.7 [10th-90th percentiles 10.7-189] µmol/L vs. 13.1 [6.5-64.3] µmol/L, p < 0.001) and blood KB (668 [168.4-3824.9] vs. 129.4 [82.6-1033.8] µmol/L, p < 0.01). Blood KB correlated with brain KB (Spearman's rho 0.56, p = 0.0013). Continuous feeding with medium-chain triglycerides-enriched enteral nutrition did not increase blood KB, and provided a modest increase in blood and brain free medium chain fatty acids. Higher brain KB at the acute TBI phase correlated with age and brain lactate, pyruvate and glutamate, but not brain glucose. These novel findings suggest that nutritional ketosis was the main determinant of cerebral KB metabolism following TBI. Age and cerebral metabolic distress contributed to brain KB supporting the hypothesis that ketones might act as alternative energy substrates to glucose. Further studies testing KB supplementation after TBI are warranted.

Protocolized Brain Oxygen Optimization in Subarachnoid Hemorrhage.

BACKGROUND: Brain tissue hypoxia (PbtO2 < 20 mmHg) is common after subarachnoid hemorrhage (SAH) and associated with poor outcome. Recent data suggest that brain oxygen optimization is feasible and reduces the time spent with PbtO2 < 20 mmHg from 45 to 16% in patients with severe traumatic brain injury. Here, we intended to quantify the brain tissue hypoxia burden despite implementation of a protocolized treatment approach in poor-grade SAH patients and to identify the simultaneous occurrence of pathologic values potentially amenable to treatment. METHODS: We present a bi-centric observational cohort study including 100 poor-grade SAH patients admitted to two tertiary care centers who underwent multimodal brain monitoring and were managed with a PbtO2-targeted protocolized approach. PbtO2 optimization (≥ 20 mmHg) included a stepwise neuro-intensive care approach, aiming to prevent low cerebral perfusion pressure (CPP), and blood hemoglobin, and to keep normocapnia, normoxemia, and normothermia. Based on routine blood gas analysis, hemoglobin, PaCO2, and PaO2 data were matched to 2-h averaged data of continuous CPP, PbtO2, core temperature, and to hourly cerebral microdialysis (CMD) samples over the first 11 days. RESULTS: Patients had a Glasgow Coma Scale of 3 (IQR 3-4) and were 58 years old (IQR 48-66). Overall incidence of brain tissue hypoxia was 25%, which was not different between both sites despite differences in the treatment approach. During brain tissue hypoxia, episodes of CPP < 70 mmHg (27%), PaCO2 < 35 mmHg (19%), PaO2 < 80 mmHg (14%), Hb < 9 g/dL (11%), metabolic crisis (CMD-lactate/pyruvate ratio > 40, and CMD-glucose < 0.7 mmol/L; 7%), and temperature > 38.3 °C (4%) were common. CONCLUSIONS: Our results demonstrate that brain tissue hypoxia remains common despite implementation of a PbtO2-targeted therapy in poor-grade SAH patients, suggesting room for further optimization.

Hypertonic Lactate to Improve Cerebral Perfusion and Glucose Availability After Acute Brain Injury.

OBJECTIVES: Lactate promotes cerebral blood flow and is an efficient substrate for the brain, particularly at times of glucose shortage. Hypertonic lactate is neuroprotective after experimental brain injury; however, human data are limited. DESIGN: Prospective study (clinicaltrials.gov NCT01573507). SETTING: Academic ICU. PATIENTS: Twenty-three brain-injured subjects (13 traumatic brain injury/10 subarachnoid hemorrhage; median age, 59 yr [41-65 yr]; median Glasgow Coma Scale, 6 [3-7]). INTERVENTIONS: Three-hour IV infusion of hypertonic lactate (sodium lactate, 1,000 mmol/L; concentration, 30 µmol/kg/min) administered 39 hours (26-49 hr) from injury. MEASUREMENTS AND MAIN RESULTS: We examined the effect of hypertonic lactate on cerebral perfusion (using transcranial Doppler) and brain energy metabolism (using cerebral microdialysis). The majority of subjects (13/23 = 57%) had reduced brain glucose availability (baseline pretreatment cerebral microdialysis glucose, < 1 mmol/L) despite normal baseline intracranial pressure (10 [7-15] mm Hg). Hypertonic lactate was associated with increased cerebral microdialysis lactate (+55% [31-80%]) that was paralleled by an increase in middle cerebral artery mean cerebral blood flow velocities (+36% [21-66%]) and a decrease in pulsatility index (-21% [13-26%]; all p < 0.001). Cerebral microdialysis glucose increased above normal range during hypertonic lactate (+42% [30-78%]; p < 0.05); reduced brain glucose availability correlated with a greater improvement of cerebral microdialysis glucose (Spearman r = -0.53; p = 0.009). No significant changes in cerebral perfusion pressure, mean arterial pressure, systemic carbon dioxide, and blood glucose were observed during hypertonic lactate (all p > 0.1). CONCLUSIONS: This is the first clinical demonstration that hypertonic lactate resuscitation improves both cerebral perfusion and brain glucose availability after brain injury. These cerebral vascular and metabolic effects appeared related to brain lactate supplementation rather than to systemic effects.

Standardized EEG interpretation in patients after cardiac arrest: Correlation with other prognostic predictors.

INTRODUCTION: Standardized EEG patterns according to the American Clinical Neurophysiology Society (ACNS) ("highly malignant", "malignant" and "benign") demonstrated good correlation with outcome after cardiac arrest (CA). However, this approach relates to EEGs after target temperature management (TTM), and correlation to other recognized outcome predictors remains unknown. OBJECTIVES: To investigate the relationship between categorized EEG and other outcome predictors, during and after TTM, at different temperatures. METHODS: In a prospective adult CA registry between 01.2014 and 06.2017, EEG at day one and two after CA were reclassified into pre-defined categories. Correlations between EEG and clinical, biochemical, neurophysiological outcome predictors, and prognosis (CPC at three months; good: 1-2), were assessed. RESULTS: Of 203 CA episodes, 31.5% were managed targeting 33 °C, 60.6% targeting 36 °C, and 7.9% with spontaneous temperature. "Highly malignant" EEG was found in 36.7% of patients at day one (predicting poor prognosis with 91% specificity -95%CI: 83%-97%-, and 63% sensitivity -95% CI: 53%-72%), and 27.1% at day two. "Benign" EEG occurred in 19.2% at day one (sensitivity to good prognosis: 35% -95%CI: 26%-46%-, positive predictive value: 89% -95% CI: 75%-97%), and in 33.2% at day two. Categorized EEG showed robust correlations with all prognostic predictors. Results were similar between EEGs recorded at day one or two, and, especially for poor prognosis, across TTM targets. DISCUSSION: Standardized EEG categorization after CA shows strong correlation with other outcome predictors, without marked variation across EEG recording time or TTM targets, underscoring its prognostic role in a multimodal approach.

Non-Ischemic Cerebral Energy Dysfunction at the Early Brain Injury Phase following Aneurysmal Subarachnoid Hemorrhage.

BACKGROUND: The pathophysiology of early brain injury following aneurysmal subarachnoid hemorrhage (SAH) is still not completely understood. OBJECTIVE: Using brain perfusion CT (PCT) and cerebral microdialysis (CMD), we examined whether non-ischemic cerebral energy dysfunction may be a pathogenic determinant of EBI. METHODS: A total of 21 PCTs were performed (a median of 41 h from ictus onset) among a cohort of 18 comatose mechanically ventilated SAH patients (mean age 58 years, median admission WFNS score 4) who underwent CMD and brain tissue PO2 (PbtO2) monitoring. Cerebral energy dysfunction was defined as CMD episodes with lactate/pyruvate ratio (LPR) >40 and/or lactate >4 mmol/L. PCT-derived global CBF was categorized as oligemic (CBF < 28 mL/100 g/min), normal (CBF 28-65 mL/100 g/min), or hyperemic (CBF 69-85 mL/100 g/min), and was matched to CMD/PbtO2 data. RESULTS: Global CBF (57 ± 14 mL/100 g/min) and PbtO2 (25 ± 9 mm Hg) were within normal ranges. Episodes with cerebral energy dysfunction (n = 103 h of CMD samples, average duration 7.4 h) were frequent (66% of CMD samples) and were associated with normal or hyperemic CBF. CMD abnormalities were more pronounced in conditions of hyperemic vs. normal CBF (LPR 54 ± 12 vs. 42 ± 7, glycerol 157 ± 76 vs. 95 ± 41 µmol/L; both p < 0.01). Elevated brain LPR correlated with higher CBF (r = 0.47, p < 0.0001). CONCLUSION: Cerebral energy dysfunction is frequent at the early phase following poor-grade SAH and is associated with normal or hyperemic brain perfusion. Our data support the notion that mechanisms alternative to ischemia/hypoxia are implicated in the pathogenesis of early brain injury after SAH.

Early prediction of coma recovery after cardiac arrest with blinded pupillometry.

OBJECTIVE: Prognostication studies on comatose cardiac arrest (CA) patients are limited by lack of blinding, potentially causing overestimation of outcome predictors and self-fulfilling prophecy. Using a blinded approach, we analyzed the value of quantitative automated pupillometry to predict neurological recovery after CA. METHODS: We examined a prospective cohort of 103 comatose adult patients who were unconscious 48 hours after CA and underwent repeated measurements of quantitative pupillary light reflex (PLR) using the Neurolight-Algiscan device. Clinical examination, electroencephalography (EEG), somatosensory evoked potentials (SSEP), and serum neuron-specific enolase were performed in parallel, as part of standard multimodal assessment. Automated pupillometry results were blinded to clinicians involved in patient care. Cerebral Performance Categories (CPC) at 1 year was the outcome endpoint. RESULTS: Survivors (n = 50 patients; 32 CPC 1, 16 CPC 2, 2 CPC 3) had higher quantitative PLR (median = 20 [range = 13-41] vs 11 [0-55] %, p < 0.0001) and constriction velocity (1.46 [0.85-4.63] vs 0.94 [0.16-4.97] mm/s, p < 0.0001) than nonsurvivors. At 48 hours, a quantitative PLR < 13% had 100% specificity and positive predictive value to predict poor recovery (0% false-positive rate), and provided equal performance to that of EEG and SSEP. Reduced quantitative PLR correlated with higher serum neuron-specific enolase (Spearman r = -0.52, p < 0.0001). INTERPRETATION: Reduced quantitative PLR correlates with postanoxic brain injury and, when compared to standard multimodal assessment, is highly accurate in predicting long-term prognosis after CA. This is the first prognostication study to show the value of automated pupillometry using a blinded approach to minimize self-fulfilling prophecy. Ann Neurol 2017;81:804-810.

Early Lance-Adams syndrome after cardiac arrest: Prevalence, time to return to awareness, and outcome in a large cohort.

INTRODUCTION: Early myoclonus after cardiac arrest (CA) is traditionally viewed as a poor prognostic sign (status myoclonus). However, some patients may present early Lance-Adams syndrome (LAS): under appropriate treatment, they can reach a satisfactory functional outcome. Our aim was to describe their profile, focusing on pharmacologic management in the ICU, time to return of awareness, and long-term prognosis. METHODS: Adults with early LAS (defined as generalized myoclonus within 96h, with epileptiform EEG within 48h after CA) were retrospectively identified in our CA registry between 2006 and 2016. Functional outcome was assessed through cerebral performance categories (CPC) at 3 months, CPC 1-2 defined good outcome. RESULTS: Among 458 consecutive patients, 7 (1.5%) developed early LAS (4 women, median age 59 years). Within 72h after CA, in normothemia and off sedation, all showed preserved brainstem reflexes and localized pain. All patients were initially treated with valproate, levetiracetam and clonazepam; additional agents, including propofol and midazolam, were prescribed in the majority. First signs of awareness occurred after 3-23 days (median 11.8); 3/7 reached a good outcome at 3 months. CONCLUSION: Early after CA, myoclonus together with a reactive, epileptiform EEG, preserved evoked potentials and brainstem reflexes suggests LAS. This condition was managed with a combination of highly dosed, large spectrum antiepileptic agents including propofol and midazolam. Even if awakening was at times delayed, good outcome occurred in a substantial proportion of patients.