Transcranial, Non-Invasive Evaluation of Potential Misery Perfusion During Hyperventilation Therapy of Traumatic Brain Injury Patients.

Hyperventilation (HV) therapy uses vasoconstriction to reduce intracranial pressure (ICP) by reducing cerebral blood volume. However, as HV also lowers cerebral blood flow (CBF), it may provoke misery perfusion (MP), in which the decrease in CBF is coupled with increased oxygen extraction fraction (OEF). MP may rapidly lead to the exhaustion of brain energy metabolites, making the brain vulnerable to ischemia. MP is difficult to detect at the bedside, which is where transcranial hybrid, near-infrared spectroscopies are promising because they non-invasively measure OEF and CBF. We have tested this technology during HV (∼30 min) with bilateral, frontal lobe monitoring to assess MP in 27 sessions in 18 patients with traumatic brain injury. In this study, HV did not lead to MP at a group level (p > 0.05). However, a statistical approach yielded 89 events with a high probability of MP in 19 sessions. We have characterized each statistically significant event in detail and its possible relationship to clinical and radiological status (decompressive craniectomy and presence of a cerebral lesion), without detecting any statistically significant difference (p > 0.05). However, MP detection stresses the need for personalized, real-time assessment in future clinical trials with HV, in order to provide an optimal evaluation of the risk-benefit balance of HV. Our study provides pilot data demonstrating that bedside transcranial hybrid near-infrared spectroscopies could be utilized to assess potential MP.

Planning for the assistance of critically ill patients in a Pandemic Situation: The experience of Vall d'Hebron University Hospital.

INTRODUCTION: In the context of community transmission of the virus, the impact of the pandemic on health-care systems, mainly on intensive care units (ICU), was expected to be devastating. Vall d'Hebron University Hospital (HUVH) implemented an unprecedented critical patient-care planning and management of resources. METHODS: We describe a cohort of critically ill patients during the first two months of the pandemic (from March 3, 2020, to May 2, 2020) in HUVH, Barcelona. In this manuscript, we report our previsions, strategies implemented, and the outcomes obtained. RESULTS: Three-thousand and thirty-three patients were admitted to the HUVH Critical Care Units. Throughout the study period, the proportion of patients on IMV or IMV and ECMO remained above 78%. Most patients were men (65%); the most common age group was 60-70 years. Twenty-three patients received ECMO, and eighteen were cannulated at another center and transferred to HUVH. At the end of the study, fourteen patients were successfully decannulated, three patients died, and the rest of the patients were still on ECMO. Eight pregnant women have been treated in the ICU, with a survival rate of 100%. The ICU mortality of patients younger than 60 years was 3.2%. The mean ICU stay of both survivors and nonsurvivors was 14 days. CONCLUSION: The adequate preparation for resource expansion for critically ill patients care, main challenges, and overall positive results can serve as a precedent for similar future scenarios.

Planning for the assistance of critically ill patients in a Pandemic Situation: The experience of Vall d'Hebron University Hospital. / Organización de la atención a pacientes críticos en situación de pandemia: Experiencia del Hospital Vall d'Hebron durante el brote de neumonía por SARS-CoV-2.

INTRODUCTION: In the context of community transmission of the virus, the impact of the pandemic on health-care systems, mainly on intensive care units (ICU), was expected to be devastating. Vall d́Hebron University Hospital (HUVH) implemented an unprecedented critical patient-care planning and management of resources. METHODS: We describe a cohort of critically ill patients during the first two months of the pandemic (from March 3, 2020, to May 2, 2020) in HUVH, Barcelona. In this manuscript, we report our previsions, strategies implemented, and the outcomes obtained. RESULTS: Three-thousand and thirty-three patients were admitted to the HUVH Critical Care Units. Throughout the study period, the proportion of patients on IMV or IMV and ECMO remained above 78%. Most patients were men (65%); the most common age group was 60-70 years. Twenty-three patients received ECMO, and eighteen were cannulated at another center and transferred to HUVH. At the end of the study, fourteen patients were successfully decannulated, three patients died, and the rest of the patients were still on ECMO. Eight pregnant women have been treated in the ICU, with a survival rate of 100%. The ICU mortality of patients younger than 60 years was 3.2%. The mean ICU stay of both survivors and nonsurvivors was 14 days. CONCLUSION: The adequate preparation for resource expansion for critically ill patients care, main challenges, and overall positive results can serve as a precedent for similar future scenarios.

Non-Invasive Estimation of Intracranial Pressure by Diffuse Optics: A Proof-of-Concept Study.

Intracranial pressure (ICP) is an important parameter to monitor in several neuropathologies. However, because current clinically accepted methods are invasive, its monitoring is limited to patients in critical conditions. On the other hand, there are other less critical conditions for which ICP monitoring could still be useful; therefore, there is a need to develop non-invasive methods. We propose a new method to estimate ICP based on the analysis of the non-invasive measurement of pulsatile, microvascular cerebral blood flow with diffuse correlation spectroscopy. This is achieved by training a recurrent neural network using only the cerebral blood flow as the input. The method is validated using a 50% split sample method using the data from a proof-of-concept study. The study involved a population of infants (n = 6) with external hydrocephalus (initially diagnosed as benign enlargement of subarachnoid spaces) as well as a population of adults (n = 6) with traumatic brain injury. The algorithm was applied to each cohort individually to obtain a model and an ICP estimate. In both diverse cohorts, the non-invasive estimation of ICP was achieved with an accuracy of <4 mm Hg and a negligible small bias. Further, we have achieved a good correlation (Pearson's correlation coefficient >0.9) and good concordance (Lin's concordance correlation coefficient >0.9) in comparison with standard clinical, invasive ICP monitoring. This preliminary work paves the way for further investigations of this tool for the non-invasive, bedside assessment of ICP.

Intensive Care to Facilitate Organ Donation: A Report on the 4-Year Experience of a Spanish Center With a Multidisciplinary Model to Promote Referrals Out of the Intensive Care Unit.

BACKGROUND: Intensive care to facilitate organ donation (ICOD) has been defined as the initiation or continuation of intensive care measures in patients with a devastating brain injury (DBI) in whom treatment for curative purposes is deemed futile, and who are considered possible organ donors, with the aim of offering donation after brain death (DBD) inside their end-of-life care plans. We describe the effect on the donation and transplantation activity of the implementation of ICOD protocol at a university hospital. METHODS: Retrospective analysis (2015-2018) of demographics and outcomes of all patients with a DBI, in whom ICOD was considered as part of their end-of-life care in Vall d'Hebron University Hospital, Barcelona. RESULTS: Of the 983 possible donors evaluated, ICOD was considered in 206 (21%), of whom 115 (55.8%) were medically unsuitable for donation. Family consent was obtained for 69 (76%) of the remaining patients. Refusal rate was twice as high when nontherapeutic ventilation was required for organ donation (34%) vs patients previously ventilated (13.6%) (P = .02). Patients subject to ICOD died in a median of 2 days (1-3 d) and 88.4% became actual donors (39 after brain death; 22 after circulatory death). Nine (17.6%) donors were finally not utilized. ICOD contributed to 29% (ranging from 27.7% in 2015 to 31.6% in 2018) of the 208 actual donors and 26% of the 603 organs transplanted. CONCLUSIONS: ICOD is well-accepted by families and offers the donation option to an increasing number of patients at our hospital. It provides an important and sustained increment of the organ pool for transplantation.

Ventricular enlargement after moderate or severe head injury: a frequent and neglected problem.

The primary goal of this study was to determine the incidence of post-traumatic ventriculomegaly (Evans' index > or = 0.30) in 95 head-injured patients with a Glasgow Coma Scale (GCS) score of < or =13 at admission. Additional objectives were to determine the relationship between an increase in ventricular size and several clinical and radiological features and outcome. A planimetric study was carried out in the sequential control computed tomography (CT) scans of 34 moderately head-injured (GCS 9-13) and 61 severely head-injured (GCS 3-8) patients with a minimum follow-up of 2 months. Between two and six CT scans were evaluated in each patient. The presence of subarachnoid hemorrhage (SAH) was registered. Evans' index was determined in all CT scans. In the final CT scan of each patient, ventricular size was related to the admission GCS score, age, the presence of SAH in the initial CT scans, type of brain lesion (classified according to the final diagnosis in the Traumatic Coma Data Bank classification), and outcome. Ventriculomegaly was found in 39.3% of patients with severe head injury and in 27.3% of those with a moderate head injury. Increased ventricular size was evident 4 weeks after injury in 57.6% and 2 months after injury in 69.7%. No relationship was found between post-traumatic ventriculomegaly and age, initial GCS score, the presence of SAH, or type of lesion (focal or diffuse). Post-traumatic ventriculomegaly was significantly correlated with outcome. Post-traumatic ventriculomegaly is a frequent and early finding in patients with moderate or severe traumatic brain injury.

Fiberoptic intraparenchymal brain pressure monitoring with the Camino V420 monitor: reflections on our experience in 163 severely head-injured patients.

To assess the safety and accuracy of the Camino intraparenchymal sensor, we prospectively evaluated hemorrhagic complications, zero-drift, infection, and system malfunction in 163 patients monitored after a severe head injury. Mean duration of intracranial pressure (ICP) monitoring was 5 +/- 2.2 days (range: 12 h to 11 days). Of the 141 patients with a control CT scan, four showed a 1-2-cc collection of blood at the catheter's end. When removed, the sensors underread the true ICP value (negative zero-drift) in 80 of the 126 sensors evaluated (63.5%). Fourteen sensors showed no zero-drift, and 32 sensors overread the true ICP value (positive zero-drift) (median: -1 mm Hg; interquartile range: -4 to +1 mm Hg). No significant relationship was found between zero-drift, the surgeon who implanted the sensor, intracranial hypertension, or duration of ICP monitoring. No clinical infections could be attributed to the devices. Sixteen patients (9.8%) required more than one ICP sensor due to malfunctioning of the system. In conclusion, continuous ICP monitoring using the Camino intraparenchymal sensor has a low complication rate. However, this sensor may underread the real ICP values in a high number of patients. The lack of correlation between duration of ICP monitoring and zero-drift suggests that, contrary to the recommendations of other reports, the intraparenchymatous Camino sensor can provide reliable readings after the fifth day of use.