Procalcitonin in Early Post Pediatric Cardiac Surgery

In This Article

Abstract and Introduction

Abstract

Objective: Procalcitonin has emerged as a promising infection marker, but previous reports from small-sized studies suggest nonspecific elevation of procalcitonin after pediatric heart surgery. As procalcitonin is increasingly used as a marker for infection in the PICU, the aim of this study was to identify factors associated with postoperative procalcitonin elevation and to investigate the role of procalcitonin as an early marker of outcome after cardiac surgery.

Design: Prospective observational study.

Setting: Single, tertiary referral PICU.

Patients: Patients aged 0–16 years following cardiac surgery with or without cardiopulmonary bypass.

Interventions: Procalcitonin was measured in all patients at admission to PICU, and on postoperative day 1 and 2. Outcome variables included major adverse event, length of stay in PICU, postoperative renal failure requiring temporary dialysis, duration of mechanical ventilation and duration of inotropic support. A major adverse event was defined as cardiac arrest, need for postoperative extracorporeal life support or death within 3 months of cardiac surgery.

Measurements and Main Results: In 221 included patients who underwent 232 operations, procalcitonin at admission to PICU was significantly associated with mechanical ventilation prior to surgery (p = 0.001), preoperative myocardial dysfunction (p = 0.002), duration of cardiopulmonary bypass (p < 0.001), intraoperative cross-clamp time (p = 0.015), and serum lactate at admission (p < 0.001). Patients suffering a major adverse event and patients with postoperative renal failure had significantly higher procalcitonin levels at admission to PICU (p = 0.04 and 0.01, respectively). Furthermore, procalcitonin levels at admission correlated significantly with the length of stay in the PICU (p = 0.005), time on mechanical ventilation (p = 0.03), and duration of inotropic support (p = 0.02).

Conclusions: Elevated levels of procalcitonin in the early phase after pediatric cardiac surgery are a marker for increased risk for major adverse events and postoperative renal failure and increased postoperative morbidity.

Introduction

The immediate postoperative phase after cardiac surgery is affected by bypass-induced systemic inflammatory response syndrome (SIRS), which is difficult to differentiate from with microorganism-induced SIRS. Procalcitonin, has emerged recently as a marker of infection in PICU. As with many other inflammatory markers, procalcitonin has been shown to be non specifically elevated in the absence of infection after uncomplicated pediatric open heart surgery,^[1] reaching a maximum level within 24 hours postoperatively.^[2] In adults, high procalcitonin levels after cardiac surgery have been shown to correlate with several severity of illness scoring systems, including the acute physiology and chronic health evaluation II and the simplified acute physiology score. Nonsurvivors were more likely to have high levels.^[3–6] There is a limited number of publications based on small sample size describing the postoperative changes of procalcitonin in children after cardiac surgery.^[1,7]

In view of the increasing use of procalcitonin as a sepsis marker in children, including postoperative patients, better knowledge on the course of procalcitonin post cardiac surgery is required. The aim of this study was to investigate the factors associated with high procalcitonin levels and to investigate the role of procalcitonin as a prognostic marker for outcome after surgery in a large cohort of infants and children undergoing surgery for congenital heart disease.

Table 1. Preoperative Risk Factors of All Included Patients
Preoperative Risk Factor	n (%)
Mechanical ventilation	10 (4)
Myocardial dysfunction	3 (1)
Seizures, stroke, intracranial hemorrhage	6 (3)
Chromosomal/syndromic abnormality	28 (12)
Necrotizing enterocolitis	2 (1)
Renal failure	2 (1)

Table 2. Indications for Cardiac Surgery of All Included Patients
Anatomic Diagnosis	n (%)	Mean Age (mo)	Mean Weight (kg)	Mean Basic Aristotle Complexity Scores	Mean Comprehensive Aristotle Complexity Scores	Mean Risk Adjusted Congenital Heart Surgery Score
Ventricular septal defect	52 (22)	23.6 (0–125)	10.4 (2.5–45.4)	7.4 (4–14.5)	8.6 (5–21)	1,929 (1,913–1,978)
Atrial septal defect	28 (12)	60.4 (6–165)	20.4 (9–41)	3.6 (3–9)	4 (3–9)	1,904 (1,901–1,921)
Coarctation of the aorta	24 (10)	14.7 (0–118)	10.3 (2.5–40)	7.6 (6–10)	9.3 (6–13)	1,934 (1,904–1,971)
Transposition of the great arteries	19 (8)	11.9 (0–145)	4.6 (2.7–15.9)	9.8 (6–12)	11.5 (6–13)	1,955 (1,943–1,991)
Tetralogy of Fallot	17 (7)	19.5 (2–174)	7.1 (3.5–13.6)	8.5 (7.5–11)	10.1 (8–17)	1,926 (1,919–1,947)
Pulmonary regurgitation	12 (5)	175.4 (141–226)	54.8 (38.5–76)	6.7 (6.5–7.5)	9.7 (6.5–12.5)	1,871 (1,609–1,943)
Totally anomalous pulmonary venous drainage	9 (4)	10.4 (0–87)	5.3 (3.1–14.6)	9 (9–9)	12.7 (9–19)	1,933 (1,920–1,961)
Pulmonary atresia	9 (4)	27.3 (0–150)	6.3 (3–10)	7.7 (6.3–9)	12.4 (6.3–16.3)	1,949 (1,943–1,951)
Double outlet right ventricle	8 (3)	18.6 (0–60)	8.7 (3–16)	9.8 (7–14.5)	12.2 (7–19.5)	1,943 (1,919–1,978)
Left ventricular outflow tract obstruction	6 (2)	66 (41–131)	16.5 (10.5–20)	6.6 (6.3–8)	9.7 (6.3–12.8)	1,914 (1,907–1,943)
Pulmonary stenosis	6 (2)	81.5 (2–141)	25.1 (4.9–38.7)	6.5 (6.0–7.0)	6.5 (6.0–7.0)	1,926 (1,909–1,943)
Hypoplastic left heart syndrome	5 (2)	14 (3–53)	7.7 (5.3–13)	7.8 (7–9)	11.3 (9.5–11)	1,934 (1,921–1,946)
Aortic valve stenosis	5 (2)	72.8 (5–201)	41.1 (8.8–69.5)	8.9 (6.3–12.5)	19.4 (6.8–12.5)	1,932 (1,906–1,959)

n = 4: aortic valve regurgitation; n = 3: right ventricular outflow tract obstruction, truncus arteriosus, Ebstein's anomaly, double inlet left ventricle, mitral regurgitation; n = 2: partially anomalous pulmonary venous drainage, vascular ring, tricuspid regurgitation; n = 1: pulmonary artery stenosis, hemitruncus arteriosus, levo: transposition of the great arteries, aortopulmonary window, mitral stenosis, ductus arteriosus, anomalous left coronary artery from the pulmonary artery.

Table 3. Multivariable Analysis (Multiple Linear Regression) of Predictors of Outcome and Preoperative Risk Factors Associated With Procalcitonin at Admission.
Predictors of Outcome	Length of Stay in the PICU		Time on Mechanical Ventilation		Duration of Inotropic Support
Predictors of Outcome	β (95% CI)	p	β (95% CI)	p	β (95% CI)	p
Mechanical ventilation	10.8 (1.9, 19.7)	0.18	222.15 (48.9, 395.4)	0.01	125.8 (53.7, 198.0)	0.01
Myocardial dysfunction	–11.3 (–27.9, 5.3)	0.18	–218.2 (–540.2, 103.8)	0.18	–105.1 (–224.5, 14.3)	0.08
Procalcitonin	2.9 (0.8, 5.1)	0.08	43.5 (1.7, 85.2)	0.04	16.3 (0.9, 31.8)	0.04

Table 4. Area Under the Receiver Operating Characteristic Curve, Cutoff, Significance, Sensitivity, Specificity, Positive and Negative Predictive Values for Procalcitonin at Admission as Predictor of Postoperative Outcome
Procalcitonin at Admission to PICU	Cutoff (ng/mL)	p	Area Under the Receiver Operating Characteristic Curve	Sensitivity (%)	Specificity (%)	Positive Predictive Value (%)	Negative Predictive Value (%)
Major adverse event	0.3	0.04	0.74	60	82	8	99
Postoperative renal failure	0.9	0.01	0.77	60	93	16	99
Length of stay in PICU over 90th percentile (= 9 d)	0.3	<0.0001	0.78	70	86	33	95
Length of mechanical ventilation over 90th percentile (= 118 hr)	0.3	<0.0001	0.79	71	86	40	95
Length of inotropic support over 90th percentile (= 184 hr)	0.3	0.005	0.69	53	83	22	96