[Recommendations For The Management Of Spontaneous Intracerebral Hemorrhage During Hospitalization]

Stroke is the leading cause of neurological disability in people over 40 years of age and the fourth leading cause of death in Argentina. In the last ten years, the indexed publications related to the treatment of ischemic stroke were more numerous than those of hemorrhagic stroke. The objective of this material is to provide local and updated recommendations for the management of patients with spontaneous intracerebral hemorrhage during hospitalization. For the writing of this manuscript, diferent specialists were convened to form working groups. Ten central topics expressed as epidemiology, initial care, imaging, blood pressure treatment, reversal of antithrombotics, indication for surgery, seizure prophylaxis, prognosis, prevention of complications and resumption of antithrombotics were raised. For each topic, the most frequent questions of daily practice were raised through PICO questions. After a systematic review of the literature, recommendations were generated, evaluated using the GRADE system and agreed between authors and patients.

Estimation of changes in cyclic lung strain by electrical impedance tomography: Proof-of-concept study

RATIONALE

Cyclic strain may be a determinant of ventilator-induced lung injury. The standard for strain assessment is the computed tomography (CT), which does not allow continuous monitoring and exposes to radiation. Electrical impedance tomography (EIT) is able to monitor changes in regional lung ventilation. In addition, there is a correlation between mechanical deformation of materials and detectable changes in its electrical impedance, making EIT a potential surrogate for cyclic lung strain measured by CT (Strain_CT ).

OBJECTIVES

To compare the global Strain_CT with the change in electrical impedance (ΔZ).

METHODS

Acute respiratory distress syndrome patients under mechanical ventilation (V_T 6 mL/kg ideal body weight with positive end-expiratory pressure 5 [PEEP 5] and best PEEP according to EIT) underwent whole-lung CT at end-inspiration and end-expiration. Biomechanical analysis was used to construct 3D maps and determine Strain_CT at different levels of PEEP. CT and EIT acquisitions were performed simultaneously. Multilevel analysis was employed to determine the causal association between Strain_CT and ΔZ. Linear regression models were used to predict the change in lung Strain_CT between different PEEP levels based on the change in ΔZ.

MAIN RESULTS

Strain_CT was positively and independently associated with ΔZ at global level (P < .01). Furthermore, the change in Strain_CT (between PEEP 5 and Best PEEP) was accurately predicted by the change in ΔZ (R² 0.855, P < .001 at global level) with a high agreement between predicted and measured Strain_CT .

CONCLUSIONS

The change in electrical impedance may provide a noninvasive assessment of global cyclic strain, without radiation at bedside.

A physiological approach to understand the role of respiratory effort in the progression of lung injury in SARS-CoV-2 infection

Deterioration of lung function during the first week of COVID-19 has been observed when patients remain with insufficient respiratory support. Patient self-inflicted lung injury (P-SILI) is theorized as the responsible, but there is not robust experimental and clinical data to support it. Given the limited understanding of P-SILI, we describe the physiological basis of P-SILI and we show experimental data to comprehend the role of regional strain and heterogeneity in lung injury due to increased work of breathing.

In addition, we discuss the current approach to respiratory support for COVID-19 under this point of view.

Progression of regional lung strain and heterogeneity in lung injury: assessing the evolution under spontaneous breathing and mechanical ventilation

BACKGROUND

Protective mechanical ventilation (MV) aims at limiting global lung deformation and has been associated with better clinical outcomes in acute respiratory distress syndrome (ARDS) patients. In ARDS lungs without MV support, the mechanisms and evolution of lung tissue deformation remain understudied. In this work, we quantify the progression and heterogeneity of regional strain in injured lungs under spontaneous breathing and under MV.

METHODS

Lung injury was induced by lung lavage in murine subjects, followed by 3 h of spontaneous breathing (SB-group) or 3 h of low V_t mechanical ventilation (MV-group). Micro-CT images were acquired in all subjects at the beginning and at the end of the ventilation stage following induction of lung injury. Regional strain, strain progression and strain heterogeneity were computed from image-based biomechanical analysis. Three-dimensional regional strain maps were constructed, from which a region-of-interest (ROI) analysis was performed for the regional strain, the strain progression, and the strain heterogeneity.

RESULTS

After 3 h of ventilation, regional strain levels were significantly higher in 43.7% of the ROIs in the SB-group. Significant increase in regional strain was found in 1.2% of the ROIs in the MV-group. Progression of regional strain was found in 100% of the ROIs in the SB-group, whereas the MV-group displayed strain progression in 1.2% of the ROIs. Progression in regional strain heterogeneity was found in 23.4% of the ROIs in the SB-group, while the MV-group resulted in 4.7% of the ROIs showing significant changes. Deformation progression is concurrent with an increase of non-aerated compartment in SB-group (from 13.3% ± 1.6% to 37.5% ± 3.1%), being higher in ventral regions of the lung.

CONCLUSIONS

Spontaneous breathing in lung injury promotes regional strain and strain heterogeneity progression. In contrast, low V_t MV prevents regional strain and heterogeneity progression in injured lungs.

Mapping regional strain in anesthetised healthy subjects during spontaneous ventilation

Introduction

Breathing produces a phenomenon of cyclic deformation throughout life. Biomechanically, deformation of the lung is measured as strain. Regional strain recently started to be recognised as a tool in the study of lung pathophysiology, but regional lung strain has not been studied in healthy subjects breathing spontaneously without voluntary or pharmacological control of ventilation. Our aim is to generate three-dimensional (3D) regional strain and heterogeneity maps of healthy rat lungs and describe their changes over time.

Methods

Micro-CT and image-based biomechanical analysis by finite element approach were carried out in six anaesthetised rats under spontaneous breathing in two different states, at the beginning of the experiment and after 3 hours of observation. 3D regional strain maps were constructed and divided into 10 isovolumetric region-of-interest (ROI) in three directions (apex to base, dorsal to ventral and costal to mediastinal), allowing to regionally analyse the volumetric strain, the strain progression and the strain heterogeneity. To describe in depth these parameters, and systematise their report, we defined regional strain heterogeneity index [1+strain SD ROI(x)]/[1+strain mean ROI(x)] and regional strain progression index [ROI(x)-mean of final strain/ROI(x)-mean of initial strain].

Results

We were able to generate 3D regional strain maps of the lung in subjects without respiratory support, showing significant differences among the three analysed axes. We observed a significantly lower regional volumetric strain in the apex sector compared with the base, with no significant anatomical systematic differences in the other directions. This heterogeneity could not be identified with physiological or standard CT methods. There was no progression of the analysed regional volumetric strain when the two time-points were compared.

Discussion

It is possible to map the regional volumetric strain in the lung for healthy subjects during spontaneous breathing. Regional strain heterogeneity and changes over time can be measured using a CT image-based numerical analysis applying a finite element approach. These results support that healthy lung might have significant regional strain and its spatial distribution is highly heterogeneous. This protocol for CT image acquisition and analysis could be a useful tool for helping to understand the mechanobiology of the lung in many diseases.

[Preoperative embolisation with absorbable gelatine sponge in intracranial meningiomas]

AIMS

The purpose of this study was to evaluate the benefits of preoperative embolisation with an absorbable gelatine sponge in selected intracranial meningiomas.

PATIENTS AND METHODS

We performed a retrospective study of a series of 33 patients who had undergone surgery for meningiomas with a diameter of over 4 cm between the years 2000 and 2007. Two groups were analysed: group A (n = 16) with preoperative embolisation and group B (n = 17) without it. Eligibility criteria for embolisation were: exclusive or predominant irrigation through the external carotid artery, high tumour flow and pronounced vascularisation through the pial branches. The location of the lesion was evaluated preoperatively; blood losses, number of units of blood transfused, surgery time and surgeon's opinion were evaluated intraoperatively.

RESULTS

A statistically significant difference was found between the group of embolised patients and those who had not been embolised as far as surgery time (217.5 +/- 69.61 versus 291.76 +/- 56.94 min; p =< 0.002) and blood loss (613.75 +/- 231.42 versus 987.65 +/- 206.68 mL; p => 0.001) were concerned. A positive coloration (r = 0.568; p = 0.001) was found between surgery time and blood loss. No statistically significant relation was observed between age and the number of units of blood transfused. Embolisation was considered to be beneficial by 75% of surgeons.

CONCLUSIONS

Preoperative embolisation with an absorbable gelatine sponge in patients with intracranial meningiomas with a diameter above 4 cm and exclusive or predominant irrigation by the external carotid artery is effective and safe; it also reduces intraoperative bleeding and surgery time.