title: Evaluation of sublingual microcirculation in a paediatric intensive care unit: prospective observational study about its feasibility and utility.
abstract: Evaluation of the microcirculation in critically ill patients is usually done by means of indirect parameters. The aim of our study was to evaluate the functional state of the microcirculation by direct visualization of sublingual microcirculation using Sidestream Dark Field Imaging, to determine the correlation between these findings and other parameters that are commonly used in the clinical practice and to assess the applicability of the systematic use of this technique in critically ill children.
  
  
  
  A prospective observational study was carried out in a Pediatric Intensive Care Unit (PICU) of a tertiary referral hospital. All patients admitted to the PICU during a three-month period were included in the study after obtaining the informed consent from the patient. Systematic evaluation of sublingual microcirculation was done in these patients (Total Vessel Density, Proportion of Perfused Vessels, Perfused Vessel Density, De Backer Score, Microvascular Flow Index, Heterogeneity Index) within the first day of admission (T1) and between the second and third day of admission (T2). Other clinical, hemodynamic, and biochemical parameters were measured and registered simultaneously. When the evaluation of the microcirculation was not feasible, the reason was registered. Descriptive analysis of our findings are expressed as means, medians, standard deviations and interquartile ranges. Mann-Whitney-Wilcoxon and Fisher tests were used to compare variables between patients with and without evaluation of the microcirculation. Pearson Correlation Coefficient (ρ) was used to evaluate the correlation between microcirculatory parameters and other clinical parameters.
  
  
  
  One hundred fine patients were included during the study period. Evaluation of the microcirculation was feasible in 18 patients (17.1%). 95.2% of them were intubated. The main reason for not evaluating microcirculation was the presence of respiratory difficulty or the absence of collaboration (95.1% on T1and 68.9% on T2). Evaluated patients had a higher prevalence of intubation and ECMO at admission (72.2% vs. 14.9% and 16.6% vs. 1.1%, respectively), and longer median duration of mechanical ventilation (0 vs. 6.5 days), vasoactive drugs (0 vs. 3.5 days) and length of stay (3 vs. 16.5 days) than non-evaluated patients. There was a moderate correlation between microcirculatory parameters and systolic arterial pressure, central venous pressure, serum lactate and other biochemical parameters used for motoring critically ill children.
  
  
  
  Systematic evaluation of microcirculation in critically ill children is not feasible in the unstable critically ill patient, but it is feasible in stable critically ill children. Microcirculatory parameters show a moderate correlation with other parameters that are usually monitored in critically ill children.
authors.affiliation: Paediatric Intensive Care Unit, Gregorio Marañón General University Hospital, Calle Doctor Castelo 47, Madrid, 28009, Spain.|Gregorio Marañón Health Research Institute, Calle Doctor Castelo 47, Madrid, 28009, Spain.|Mother and Child Health and Development Network (Red SAMID), RETICS funded by the PN I+D+I 2008-2011, ISCIII-Sub-Directorate General for Research Assessment and Promotion and the European Regional 10.1186/s12887-017-0837-5 Development Fund, ref. RD12/0026., Madrid, Spain.
authors.forename: Rafael
authors.initials: R
authors.lastname: González
authors.affiliation: Paediatric Intensive Care Unit, Gregorio Marañón General University Hospital, Calle Doctor Castelo 47, Madrid, 28009, Spain.|Gregorio Marañón Health Research Institute, Calle Doctor Castelo 47, Madrid, 28009, Spain.|Mother and Child Health and Development Network (Red SAMID), RETICS funded by the PN I+D+I 2008-2011, ISCIII-Sub-Directorate General for Research Assessment and Promotion and the European Regional 10.1186/s12887-017-0837-5 Development Fund, ref. RD12/0026., Madrid, Spain.
authors.forename: Jorge
authors.initials: J
authors.lastname: López
authors.affiliation: Paediatric Intensive Care Unit, Gregorio Marañón General University Hospital, Calle Doctor Castelo 47, Madrid, 28009, Spain.|Gregorio Marañón Health Research Institute, Calle Doctor Castelo 47, Madrid, 28009, Spain.|Mother and Child Health and Development Network (Red SAMID), RETICS funded by the PN I+D+I 2008-2011, ISCIII-Sub-Directorate General for Research Assessment and Promotion and the European Regional 10.1186/s12887-017-0837-5 Development Fund, ref. RD12/0026., Madrid, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Urbano
authors.affiliation: Paediatric Intensive Care Unit, Gregorio Marañón General University Hospital, Calle Doctor Castelo 47, Madrid, 28009, Spain.|Gregorio Marañón Health Research Institute, Calle Doctor Castelo 47, Madrid, 28009, Spain.|Mother and Child Health and Development Network (Red SAMID), RETICS funded by the PN I+D+I 2008-2011, ISCIII-Sub-Directorate General for Research Assessment and Promotion and the European Regional 10.1186/s12887-017-0837-5 Development Fund, ref. RD12/0026., Madrid, Spain.
authors.forename: María José
authors.initials: MJ
authors.lastname: Solana
authors.affiliation: Paediatric Intensive Care Unit, Gregorio Marañón General University Hospital, Calle Doctor Castelo 47, Madrid, 28009, Spain.|Gregorio Marañón Health Research Institute, Calle Doctor Castelo 47, Madrid, 28009, Spain.|Mother and Child Health and Development Network (Red SAMID), RETICS funded by the PN I+D+I 2008-2011, ISCIII-Sub-Directorate General for Research Assessment and Promotion and the European Regional 10.1186/s12887-017-0837-5 Development Fund, ref. RD12/0026., Madrid, Spain.
authors.forename: Sarah Nicole
authors.initials: SN
authors.lastname: Fernández
authors.affiliation: Gregorio Marañón Health Research Institute, Calle Doctor Castelo 47, Madrid, 28009, Spain.|Mother and Child Health and Development Network (Red SAMID), RETICS funded by the PN I+D+I 2008-2011, ISCIII-Sub-Directorate General for Research Assessment and Promotion and the European Regional 10.1186/s12887-017-0837-5 Development Fund, ref. RD12/0026., Madrid, Spain.
authors.forename: María José
authors.initials: MJ
authors.lastname: Santiago
authors.affiliation: Paediatric Intensive Care Unit, Gregorio Marañón General University Hospital, Calle Doctor Castelo 47, Madrid, 28009, Spain. pielvi@hotmail.com.|Gregorio Marañón Health Research Institute, Calle Doctor Castelo 47, Madrid, 28009, Spain. pielvi@hotmail.com.|Mother and Child Health and Development Network (Red SAMID), RETICS funded by the PN I+D+I 2008-2011, ISCIII-Sub-Directorate General for Research Assessment and Promotion and the European Regional 10.1186/s12887-017-0837-5 Development Fund, ref. RD12/0026., Madrid, Spain. pielvi@hotmail.com.|School of Medicine, Complutense University of Madrid, Madrid, Spain. pielvi@hotmail.com.
authors.forename: Jesús
authors.initials: J
authors.lastname: López-Herce
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003422:Critical Care / Q000379:methods*; D016638:Critical Illness; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007223:Infant; D015278:Intensive Care Units, Pediatric; D008297:Male; D008833:Microcirculation; D008991:Monitoring, Physiologic / Q000379:methods; D009060:Mouth Floor / Q000098:blood supply*; D011446:Prospective Studies
keywords: Critically ill child; Microcirculation; Monitoring; Paediatric intensive care; Shock