The Immunnity Status Of Patients In Paediatric Intensive Care Unit In Early Phase

Background/ObjectivesCritical illness is a disease or state in which death is possible or imminent. There is increasing evidence show that,during critical illness,there is a systemic anti-inflammatory state intended to avoid the spread of the local pro-inf-lammatory response.But overwhelming anti-inflammatory response results to im munosuppression.Researches indicate an immunity status called immune dysfunction in patients of sepsis,injury,stress,et al.The changes include lymphopenia, CD4⁺/CD8⁺ ratio inversion,immune profile shift,T cell apoptosis,decrease of polymorphonuclear neutrophils' chemotaxis and phagocytic and increase of O₂ radicals.The complement changes and immunoglobulin reduces.But there are different viewpoints about when immune dysfunction onsets.Some researches show it's a biphasic pattern including a systemic inflammatory response during the first phase and immune paralysis during the second.In addition to this biphasic model,there is evidence indicating that inflammation and immunoparalysis do not only occur in sequence to each other but in parallel.We undertook a study about the immunity status of admissions to the paediatric intensive care unit,include trauma and infective patients.MethodsWe undertook a retrospective discriptive study of critical ill admissions to the paediatric intensive care unit to find out their immune status.The objectives were scored in 24 hours after admission and were divided into critical ill children versus without critical illness,sepsis versus non-sepsis.3ml peripheral blood was withdrawn at the same time.The peripheral T lymphocyte subsets CD3⁺,CD4⁺,CD8⁺ T cells,the function of polymorphonuclear neutrophil,complements,immunoglobins were measured.Outcomes were recorded.All the statistics were anlysized by SPSS11.5.ResultsWe studied 73 admissions to the paediatric intensive care unit.There were 22 critical ill children,51 uncritical ill children and 36 septic patients,37 non-septic patients.17 of them died.Severe pneumonia counted for a high proportion as primary disease.The mortality of critical ill children was 40.90%,significantly higher than that in children without critical illness.The motality on septic children was 23.29%, significantly higher than that in non-septic children.1.25 patients had elevated white blood cell count which high PMN proportion dominated.The mean of patients' white blood cell count in sepsis and non-sepsis group,critical and uncritical group had no significant difference.But there were more children having elvated WBC in septic group than in non-septic group.2.61.64%of the patients had elavation PBS control value.The mean value of PBS control in septic group was(32.33±30.32)%.No significant difference was found between septic and non-septic group.3 patients had low PMN activity after PMA stimulation and all were septic children.3.50.68%of the patients had low CD3⁺ T,CD4⁺ T,CD8⁺ T lymphocyte simultaneously.The mean of septical patinets' CD3⁺ T lymphocyte percentage was 55.83±15.36%without significant difference from non-septical patients'.The mean of CD3⁺ T lymphocyte percentage in patients with critical illness score less than 80 was 55.83±15.36%and han no significant difference from patients with critical illness score more than 80.The mean of CD4⁺ T lymphocyte percentage and CD8⁺ T lymphocyte percentage had no significant difference between septical and non-septical patients,either between critical group and non-critical group.But the mortality of patients with low CD3⁺ T,CD4⁺ T lymphocyte in critical ill group was higher than that in uncritical ill group.4.Critical ill children had low serum C3,CH50 level than those uncritical children's. Children who died had higher C3 level than those survived.5.17.81%of the subjects had low IgG level.The percentage of children with low IgG in critical ill group was 27.27%,significantly higher than that of uncritical ill group.The percentage of children with high IgM in critical ill group was 4.55%, significantly lower than that of uncritical ill group.Conclusion1.Few patients had dysfunction of PMN's respiratory burst.2.The admissions of PICU had low T lymphocyte subsets CD3⁺,CD4⁺,CD8⁺ T cells.3.Patients of critical illness had low serum C3 and CH50 level.Patients that had an outcome of death had a relatively high C3 level than those survived.4.The proportion of patients with low IgG level in critical ill children were high and the proportion of patients with high IgM level in critical ill children were low.