Background

Microcirculatory compartment involves those small blood vessels (below 20 micrometers) in which substance and gas exchange takes place between blood and tissue cells. Microcirculatory disturbances have been independently linked to adverse outcomes in critically ill patients. Although functioning of the microcirculatory compartment has been clearly linked to systemic hemodynamics, in certain clinical conditions, uncoupling of micro and macrocirculation might lead to tissue hypoperfusion and organ failure. Thus, in critically ill children, it is very important to guarantee both, adequate systemic and microcirculatory blood flow.

Microcirculation has been mostly evaluated using different indirect methods: from physical examination with determination of the temperature gradient or capillary refill time, to determination of different biochemical markers of tissue perfusion. In the last years introduction of different generations of hand-held videomicroscopy devices has allowed direct evaluation of different microcirculatory parameters.

Objectives

Main objective of the presentation is to discuss existing evidence about the use of different microcirculatory evaluation methods.

We will make special focus discussing last recommendations existing on microcirculatory evaluation using hand-held videomicroscopy devices, but also we will discuss applications and existing recommendations of microcirculatory evaluation in different critical clinical situations.

Methods

Revision of currently existing evidence of the aplication of microcirculatory evaluation in the management of pediatric critically ill patients and existing microcirculatory evaluation recommendations.

Results

We will review different aspects of the topic.

Conclusion

Adequate microcirculatory functioning is crucial to guarantee organ functioning in critically ill pediatric patients. Evaluation of microcirculation is possible using different techniques. Some of them have specific recommendations about their clinical use.

Background

Previous 1H-MRS studies reported significant decrease of major neuronal marker (N-acetylaspartate (NAA)) concentration after severe TBI, The possible reasons of NAA reduction is not still completely known. Disruption of the NAA synthesis from aspartate Asp may result to its decrease.

Objectives

The main idea of this study is investigation of dynamic changes in NAA, Asp and glutamate (Glu) concentrations using proton magnetic resonance spectroscopy.

Methods

We studied 2 patients groups: Eight children (mean age-14±2 years) with acute sTBI (23±4 hours after trauma) and seven patients with chronic sTBI (3 months after trauma). were Control group consisted of 11 healthy children (mean age-15±1 years) without history of any TBI. ^AspMEGA PRESS were acquired from voxels located in the frontal lobe (fig.1).

Results

NAA and Asp concentrations are reduced in the both patient groups (acute sTBI - on 65% and 61%, chronic sTBI – on 65% and 61%). Glu is significantly reduced only in acute sTBI, however, a significant decrease in the Asp/Glu ratio was found in patients with chronic sTBI.

Conclusion

Since stoichiometric Asp-Glu ratio is maintained by the exchange of glutamate with mitochondrial aspartate, significant reduction of [Asp]/[Glu] may indicates a disruption in the normal functioning of the malate-aspartate shuttle in chronic sTBI. Reduced Glu and Asp concentrations in acute sTBI are associated with excitotoxicity.

This work was supported by RFBR grant 17-04-01149.

Background

Hyperoxia is harmful and can increase morbidity & mortality. Baseline data from our Paediatric Intensive Care Unit (PICU) reflected 80/185 episodes with Oxygen Saturation measurements (SpO2) ≥ 97% and Fraction of Inspired Oxygen (FiO2) >21%. FiO2 was not weaned in 55% of these episodes.

Objectives

To wean FiO2 in ≥ 90% of episodes when SpO2 are ≥ 97%; in invasively ventilated patients within their first 10 days of admission to the PICU, in a 5 month study period.

Methods

SpO2, FiO2 and weaning records were collected prospectively from Clinical Information System at fixed times (3:00,7:00,11:00,15:00,19:00,23:00) on Monday, Thursday and Saturday over 8 weeks in two phases 4 weeks apart. Patients with cardiac disease and pulmonary hypertension were excluded. PDSA cycles were used for every test of change and Statistical Process Control (SPC) charts plotted to determine change. Interventions included education (Phase 1, 2), raising awareness (Phase 1, 2), and visual and verbal reminders (Phase 2).

Results

In Phase 1, the percentage of FiO2 weaning reached 67% at best and gradually decreased to 60% by the end of 8 weeks. In Phase 2, the percentage of weaning steadily increased reaching 89.5% by the end of 8 weeks. Using visual reminders and one to one discussion with nurses to raise awareness brought maximum improvement. Poor rates of weaning seen over weekends and nights also improved with completion of the project.

Conclusion

Once awareness was raised, regular personal reminders to staff responsible for weaning ventilation improved FiO2 weaning habits and staff involvement in this quality improvement.

Background

Recent data suggest that normocapnia could be the ventilatory target after returning of spontaneous circulation (ROSC).

Objectives

To compare ventilation, oxygenation and haemodynamics during the first hour after ROSC with two respiratory rates.

Methods

50 piglet (median weight 11 kg) which achieved ROSC after an experimental model of asphyxial cardiopulmonary arrest (CA), were randomized to 20 or 30 rpm (tidal volume 10 ml/kg). Arterial blood gases and haemodynamic parameters were obtained 5, 15, 30 and 60 minutes after ROSC.

Results

There were no statistical differences between both groups in any variable before ROSC. After ROSC, there were no differences in arterial blood pressure, cerebral blood flow or somatic/cerebral near-infrared spectroscopy either. Lower PaCO₂ values was observed in the 30 rpm group (Table 1) with no differences in oxygenation. Normocapnia was achieved in a higher number of piglets in the 30 rpm group at 5 min (48% vs 8% p 0.002), 15 min (90.5% vs 12.5% p<0.001), 30 min (87% vs 32% p<0.001) and 60 min (91.3% vs 60% p 0.012). There was one hyperventilated piglet in the 30 rpm group at 30 and 60 minutes after ROSC.

Conclusion

30 rpm is better than 20 rpm to achieve normocapnia in the first hour after ROSC in a model of asphyxial pediatric CA.