The principal purpose of this study is to describe the changes in cerebral circulation (assessed by transcranial ultrasound) and oxygenation (assessed by Near InfraRed spectroscopy, NIRS) during resuscitation for hemodynamic failure (arterial hypotension or shock) in critically ill children treated with vasoactive or inotropic drugs. The secondary objectives are : i) to evaluate the association between an alteration of cerebral circulation and/or oxygenation and an alteration in macro-circulatory parameters (Mean Arterial Blood Pressure and cardiac output) or a bad outcome, ii) to study if cerebral autoregulation is impaired
Pediatric shock is a frequent and serious cause of hospitalization in pediatric intensive care unit that can lead to multi-organ failure and death. Its early recognition improves patients' outcome, as well as the establishment of targeted guidelines pursuing normalization of macro-circulatory parameters (ie blood pressure and lactate). However, regional hypoperfusion leading to organ failure can be present before the alteration of these parameters, and persist after their restoration. Brain lesions are common in critically ill children with cerebral hypoperfusion, since they may have impaired autoregulation and permeable blood-brain barrier. Vasoactive and inotropic drugs used for hemodynamic resuscitation should restore systemic and regional circulation, but may be inadequate on brain perfusion because of i) their variable and unpredictable cardiovascular effects , and ii) a strong interindividual variability between patients. As such, the impact of this medication on cerebral circulation and oxygenation is unknown. Monitoring cerebral circulation and oxygenation during a hemodynamic resuscitation using catecholamines is a first step to identify risk factors of an altered brain perfusion, and to improve treatment of shock.
Study Type
OBSERVATIONAL
Enrollment
27
Regional Cerebral Oxygen saturation (rScO2 ) values will be collected for all patients during the procedure using a 2-wavelength (730-810 nm) cerebral oxymeter (monitor INVOS 5100C®, Medtronics). Two transducers will be placed on both fronto-parietal sides of the patient's head. To assess the balance between oxygen delivery and consumption, the Fractional cerebral Tissue Oxygen Extraction (FTOE) will be calculated as this ratio: FTOE=\[SpO2-rScO2\]/SpO2. Data will be collected for a period of 3 hours starting from the beginning of catecholamine treatment.
Transcranial Doppler ultrasound will be performed for all patients during the procedure using a VIVID S-5 (General Electric®) echograph. All examinations will be performed by a single trained operator. A 3 MHz probe will be placed on left and right temporal window to detect signal from the middle cerebral artery. 2 measures will be performed for each side to have the mean of the two measures; In case of difference in measures of more than 20%, a third measure will be performed. Measures will be performed for a period of 3 hours starting from the beginning of catecholamine treatment.
Transthoracic echocardiography will be realized for all patients during the procedure using a transthoracic ultrasound device (VIVID S-5, General Electric®) with a 3 to 6 MHz probe. All examinations will be performed by a single trained operator. Two echocardiographic views will be examined to assess cardiac output : the two-chamber long-axis view to measure sub-aortic diameter (d), and the four-chamber view to measure the Left ventricular outflow tract velocity time integral (LVOT VTI). Cardiac output (Qc) will then be calculated taking account these parameters and heart rate with this formula : Qc = \[π x d2 x VTI x HR\] / 4 2 measures will be performed to have the mean of the two measures; In case of difference in measures of more than 20%, a third measure will be performed. Measures will be performed for a period of 3 hours starting from the beginning of catecholamine treatment.
Hôpital Trousseau
Paris, France
Hôpital Necker
Paris, France
Hôpital Robert Debré
Paris, France
Near InfraRed Spectroscopy (NIRS)
rScO2 and FTOE variations (left and right). A cerebral desaturation will be defined by a rScO2 delta \>20% from the baseline value (before premedication).
Time frame: 3 hours
Variations of velocities of middle cerebral artery (left and right), in cm/s
Transcranial Doppler ultrasound
Time frame: 3 hours
Variations of pulsatility index of middle cerebral artery (left and right)
Transcranial Doppler ultrasound
Time frame: 3 hours
Variations of resistance index of middle cerebral artery (left and right)
Transcranial Doppler ultrasound
Time frame: 3 hours
Mean arterial pressure
Correlation between microcirculatory parameters (transcranial Doppler ultrasound and NIRS) and mean arterial pressure
Time frame: 3 hours
Cardiac output calculated with Left ventricular outflow tract velocity time integral (LVOT VTI) measured by cardiac ultrasound
Correlation between microcirculatory parameters (transcranial Doppler ultrasound and NIRS) and cardiac output (Qc), which will be calculated taking account these parameters and heart rate with this formula : Qc = \[π x d2 x VTI x HR\] / 4
Time frame: 3 hours
PEdiatric logistic organ dysfunction score (PELOD-2)
Correlation between cerebral perfusion (transcranial Doppler ultrasound and NIRS) and Organ Dysfunction assessed by PELOD-2 score. PELOD-2 score includes 10 variables corresponding to 5 organ dysfunctions. Values extend from 0 (best outcome) to 33 (worst outcome).
Time frame: 3 hours
Death in pediatric intensive care unit
Correlation between cerebral perfusion (transcranial doppler ultrasound and NIRS) and outcome (PELOD-2, death in PICU = pediatric intensive care unit)
Time frame: 3 hours
Cerebral autoregulation evaluation
Cerebral autoregulation will be estimated thanks to a Pearson coefficient correlation between mean arterial pressure (MAP) and rScO2. A ratio MAP/rScO2 \> 0,5 defines an impaired cerebral autoregulation
Time frame: 3 hours
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.