[Kinetics of C-reactive protein and procalcitonin after paediatric cardiac surgery]

Procalcitonin Is a Better Biomarker than C-Reactive Protein in Newborns Undergoing Cardiac Surgery: The PROKINECA Study

OBJECTIVES

To assess the kinetics of procalcitonin (PCT) and C-reactive protein (CRP) in newborns after cardiothoracic surgery (CS), with and without cardiopulmonary bypass, and to assess whether PCT was better than CRP in identifying sepsis in the first 72 hours after CS.

PATIENTS AND METHODS

This is a prospective study of newborns admitted to the neonatal intensive care unit after CS.

INTERVENTIONS

PCT and CRP were sequentially drawn 2 hours before surgery and at 0, 12, 24, 48, and 72 hours after surgery.

RESULTS

A total of 65 patients were recruited, of which 14 were excluded because of complications. We compared the kinetics of PCT and CRP after CS in bypass and non-bypass groups without sepsis; there were no differences in the PCT values at any time (24 hours, P = 0.564; 48 hours, P = 0.117; 72 hours, P = 0.076). Thirty-five patients needed bypass, of whom four were septic (11.4%). Significant differences were detected in the PCT values on comparing the septic group to the nonseptic group at 48 hours after cardiopulmonary bypass (P = 0.018). No differences were detected in the CRP values in these groups. A suitable cutoff for sepsis diagnosis at 48 hours following bypass would be 5 ng/mL, with optimal area under the curve of 0.867 (confidence interval 0.709–0.958), P < 0.0001, and sensitivity and specificity of 87.5% (29.6–99.7) and 72.6% (53.5–86.4), respectively.

CONCLUSION

This is a preliminary study but PCT seems to be a good biomarker in newborns after CS. Values over 5 ng/mL at 48 hours after CS should alert physicians to the high risk of sepsis in these patients.

Cardiopulmonary bypass changes the plasma proteome in children undergoing tetralogy of Fallot repair

Introduction:

Cardiopulmonary bypass (CPB) can be associated with deleterious clinical effects. However, the impact of CPB on inflammatory, immunological and other homeostatic pathways remains poorly understood. We investigated the impact of CPB on the plasma proteome in children undergoing tetralogy of Fallot repair.

Methods:

Blood samples were taken from 20 children prior to and at the end of CPB and 6h, 12h and 24h after CPB. Plasma was analysed by liquid chromatography-mass spectrometry (LC-MS) in a label-free, untargeted approach. Data were analysed using Genedata software to identify peptides that were differentially expressed (p<0.01 above a false discovery rate). Proteins were identified from peptides that demonstrated differential expression.

Results:

The proteins that were found to be differentially expressed were haptoglobin isoform 1 preproprotein, isoform 2 of semaphorin-6C, vitamin D-binding protein, inter-alpha-trypsin inhibitor, ceruloplasmin, apolipoprotein B100 and fibrinogen alpha.

Conclusion:

CPB alters the plasma proteome with differences most apparent at 6h and 12h post CPB. There was a return to baseline with no proteins differentially regulated by 24h.

Alkaline phosphatase activity after cardiothoracic surgery in infants and correlation with post-operative support and inflammation: a prospective cohort study

Introduction

Limited evidence suggests that serum alkaline phosphatase activity may decrease after cardiac surgery in adults and children. The importance of this finding is not known. Recent studies, however, have identified a potential role for alkaline phosphatase as modulator of inflammation in multiple settings, including during adult cardiopulmonary bypass. We sought to describe the change in alkaline phosphatase activity after cardiothoracic surgery in infants and to assess for a correlation with intensity and duration of post-operative support, markers of inflammation, and short-term clinical outcomes.

Methods

Sub-analysis of a prospective observational study on the kinetics of procalcitonin in 70 infants (≤90 days old) undergoing cardiothoracic surgery. Subjects were grouped based on the use of cardiopulmonary bypass and delayed sternal closure. Alkaline phosphatase, procalcitonin, and C-reactive protein (CRP) levels were obtained pre-operation and on post-operative day 1. Mean change in alkaline phosphatase activity was determined in each surgical group. Generalized linear modeling and logistic regression were employed to assess for associations between post-operative alkaline phosphatase activity and post-operative support, inflammation, and short term outcomes. Primary endpoints were vasoactive-inotropic score at 24 hours and length of intubation. Secondary endpoints included procalcitonin/CRP levels on post-operative day 1, length of hospital stay, and cardiac arrest or death.

Results

Mean decrease in alkaline phosphatase was 30 U/L (p = 0.01) in the non-bypass group, 114 U/L (p<0.0001) in the bypass group, and 94 U/L (p<0.0001) in the delayed sternal closure group. On multivariate analysis, each 10 U/L decrease in alkaline phosphatase activity on post-operative day 1 was independently associated with an increase in vasoactive-inotropic score by 0.7 (p<0.0001), intubation time by 6% (p<0.05), hospital stay by 5% (p<0.05), and procalcitonin by 14% (P<0.01), with a trend towards increased odds of cardiac arrest or death (OR 1.3; p = 0.06). Post-operative alkaline phosphatase activity was not associated with CRP (p = 0.7).

Conclusions

Alkaline phosphatase activity decreases after cardiothoracic surgery in infants. Low post-operative alkaline phosphatase activity is independently associated with increased procalcitonin, increased vasoactive/inotropic support, prolonged intubation time, and prolonged hospital stay. Alkaline phosphatase may serve as a biomarker and potential modulator of post-operative support and inflammation following cardiothoracic surgery in infants.

Procalcitonin: a useful biomarker to discriminate infection after cardiopulmonary bypass in children

OBJECTIVE

To determine whether procalcitonin discriminates between postcardiopulmonary bypass inflammatory syndrome and infectious complication in children better than does C-reactive protein.

DESIGN

Prospective study of children admitted to the intensive care unit after cardiopulmonary bypass.

PATIENTS

Classified according to a diagnosis of systemic inflammatory response syndrome and bacterial infection or systemic inflammatory response syndrome but no bacterial infection. Two hundred thirty-one cases were recruited.

MEASUREMENT AND MAIN RESULTS

Procalcitonin, C-reactive protein, and leukocyte count were measured daily from surgery until day 3. Twenty-two patients were infected (9.5%). Significant differences were detected in the procalcitonin values of the infected group vs. the noninfected group, especially at day 2 (p = .000). There were no differences in the C-reactive protein values. The optimal cutoff for procalcitonin was >2 ng/mL at day 1 and above 4 ng/mL at the day 2. There was a greater sensitivity and specificity than with C-reactive protein as an infection predictor.

CONCLUSION

Procalcitonin is useful in the diagnosis of bacterial infection after cardiopulmonary bypass. Because procalcitonin kinetics are different in postcardiopulmonary bypass patients, the cutoff to diagnose infection should be different from the normal cutoff.