Chylothorax after pediatric cardiac surgery complicates short-term but not long-term outcomes-a propensity matched analysis.

BACKGROUND: The occurrence of postoperative chylothorax in children with congenital heart disease is a rare and serious complication in cardiac intensive care units (ICUs). The aim of our study was to identify the perioperative characteristics, treatment options, resource utilization and long term complications of patients having chylothorax after a pediatric cardiac surgery. METHODS: Patients were retrospectively assessed for the presence of chylothorax between January 2002 and December 2012 in a tertiary national cardiac center. Occurrence, treatment options and long term outcomes were analyzed. Chylothorax patients less than 2 years of age were analyzed using propensity-matched statistical analysis in regard to postoperative complications after discharge. RESULTS: During the 10-year period, 48 patients had chylothorax after pediatric cardiac surgery. The highest incidence was observed on the second postoperative day (7 patients, 14.6%). Seven patients (14.6% of the chylothorax population) died. During the follow up period, 5 patients had additional thromboembolic complications (2 had confirmed thrombophilia). Eleven patients had a genetic abnormality (3 had Down's syndrome, 3 had Di-Giorge's syndrome, 1 had an IgA deficiency and 4 had other disorders). During the reoperations (49 cases), no chylothorax occurred. After propensity matching, the occurrence of pulmonary failure (P=0.001) was significantly higher in the chylothorax group, and they required prolonged mechanical ventilation (P=0.002) and longer hospitalization times (P=0.01). After discharge, mortality and neurologic and thromboembolic events did not differ in the matched groups. CONCLUSIONS: Chylothorax is an uncommon complication after pediatric cardiac surgery and is associated with higher resource utilization. Chylothorax did not reoccur during reoperations and was not associated with higher mortality or long-term complications in a propensity matched analysis.

Fluid Overload Is Associated With Higher Mortality and Morbidity in Pediatric Patients Undergoing Cardiac Surgery.

OBJECTIVES: Fluid overload after pediatric cardiac surgery is common and has been shown to increase both mortality and morbidity. This study explores the risk factors of early postoperative fluid overload and its relationship with adverse outcomes. DESIGN: Secondary analysis of the prospectively collected data of children undergoing open-heart surgery between 2004 and 2008. SETTING: Tertiary national cardiac center. PATIENTS: One thousand five hundred twenty consecutive pediatric patients (<18 years old) were included in the analyses. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: In the first 72 hours of the postoperative period, the daily fluid balance was calculated as milliliter per kilogram and the daily fluid overload was calculated as fluid balance (L)/weight (kg) × 100. The primary endpoint was in-hospital mortality; the secondary outcomes were low cardiac output syndrome and prolonged mechanical ventilation. One thousand three hundred and sixty-seven patients (89.9%) had a cumulative fluid overload below 5%; 120 patients (7.8%), between 5% and 10%; and 33 patients (2.1%), above 10%. After multivariable analysis, higher fluid overload on the day of the surgery was independently associated with mortality (adjusted odds ratio, 1.14; 95% CI, 1.008-1.303; p = 0.041) and low cardiac output syndrome (adjusted odds ratio, 1.21; 95% CI, 1.12-1.30; p = 0.001). Higher maximum serum creatinine levels (adjusted odds ratio, 1.01; 95% CI, 1.003-1.021; p = 0.009), maximum vasoactive-inotropic scores (adjusted odds ratio, 1.01; 95% CI, 1.005-1.029; p = 0.042), and higher blood loss on the day of the surgery (adjusted odds ratio, 1.01; 95% CI, 1.004-1.025; p = 0.015) were associated with a higher risk of fluid overload that was greater than 5%. CONCLUSIONS: Fluid overload in the early postoperative period was associated with higher mortality and morbidity. Risk factors for fluid overload include underlying kidney dysfunction, hemodynamic instability, and higher blood loss on the day of the surgery.

A comparison of the systems for the identification of postoperative acute kidney injury in pediatric cardiac patients.

BACKGROUND: The pediatric-modified Risk, Injury, Failure and Loss, and End-Stage (pRIFLE) criteria and a different but conceptually similar system termed Acute Kidney Injury Network (AKIN) were created to standardize the definition of acute kidney injury (AKI) in children. Kidney Disease: Improving Global Outcomes (KDIGO) currently recommends a combination of AKIN and pRIFLE in AKI. This study aimed to compare the three classifications for predicting AKI in pediatric patients undergoing cardiac operations. METHODS: We analyzed the prospectively collected data of 1,489 consecutive pediatric patients undergoing cardiac operations between January 2004 and December 2008. AKI presence and severity was assessed for each classification using the change in serum creatinine and estimated creatinine clearance levels calculated by the Schwartz equation. RESULTS: AKI was present in 285 (20%), 481 (34%), and 409 (29%) patients according to the AKIN, pRIFLE, and KDIGO systems, respectively. The KDIGO classification categorized 121 patients (8%) who were placed in the AKIN 0 category, whereas the pRIFLE system categorized 74 (5%) in KDIGO 0 and 200 (14%) in AKIN 0 stages as having an AKI. The overall mortality rate was 3.9%. The KDIGO stage III (odds ratio [OR], 18.8; 95% confidence interval [CI], 9.6 to 36.6, p < 0.001), the AKIN stage III (OR, 38.3; 95% CI, 20.6 to 70.9, p < 0.001), and pRIFLE failure group (OR, 13.6, 95% CI, 7 to 26.3; p < 0.001) were associated with increased mortality. CONCLUSIONS: The pRIFLE system was the most sensitive test in detecting AKI, and this was especially so in the infant age group and also in the early identification of AKI in low-risk patients. The AKIN system was more specific and detected mostly high-risk patients across all age groups. The KDIGO classification system fell between pRIFLE and AKIN in performance. All three had increasing severity of AKI associated with mortality.

Impact of the insulin and glucose content of the postoperative fluid on the outcome after pediatric cardiac surgery.

INTRODUCTION: The aim of this study was to investigate the role of the insulin and glucose content of the maintenance fluid in influencing the outcomes of pediatric patients undergoing heart surgery. METHODS: A total of 2063 consecutive pediatric patients undergoing cardiac surgery were screened between 2003 and 2008. A dextrose and an insulin propensity-matched group were constructed. In the dextrose model, 5% and 10% dextrose maintenance infusions were compared below 20 kg of weight. RESULTS: A total of 171 and 298 pairs of patients were matched in the insulin and glucose model, respectively. Mortality was lower in the insulin group (12.9% vs. 7%, p = 0.049). The insulin group had longer intensive care unit (ICU) stay [days, 10.9 (5.8-18.4) vs. 13.7 (8.2-21), p = 0.003], hospital stay [days, 19.8 (13.6-26.6) vs. 22.7 (17.6-29.7), p < 0.01], duration of mechanical ventilation [hours, 67 (19-140) vs. 107 (45-176), p = 0.006], and the incidence of severe infections (18.1% vs. 28.7%, p = 0.01) and dialysis (11.7% vs. 24%, p = 0.001) was higher. In the dextrose model, the incidence of pulmonary complications (13.09% vs. 22.5%, p < 0.01), low cardiac output (17.11% vs. 30.9%, p < 0.01), and severe infections (10.07% vs. 20.5%, p < 0.01) was higher, and the duration of the hospital stay [days, 16.4 (13.1-21.6) vs. 18.1 (13.8-24.6), p < 0.01] was longer in the 10% dextrose group. CONCLUSIONS: Insulin treatment appeared to decrease mortality, and lower glucose content was associated with lower occurrence of adverse events.

Down syndrome and postoperative complications after paediatric cardiac surgery: a propensity-matched analysis.

OBJECTIVES: The incidence of congenital heart disease is ~50%, mostly related to endocardial cushion defects. The aim of our study was to investigate the postoperative complications that occur after paediatric cardiac surgery. METHODS: Our perioperative data were analysed in paediatric patients with Down syndrome undergoing cardiac surgery. We retrospectively analysed the data from 2063 consecutive paediatric patients between January 2003 and December 2008. After excluding the patients who died or had missing data, the analysed database (before propensity matching) contained 129 Down patients and 1667 non-Down patients. After propensity matching, the study population comprised 222 patients and 111 patients had Down syndrome. RESULTS: Before propensity matching, the occurrences of low output syndrome (21.2 vs 32.6%, P = 0.003), pulmonary complication (14 vs 28.7%, P < 0.001) and severe infection (11.9 vs 22.5%, P = 0.001) were higher in the Down group. Down patients were more likely to have prolonged mechanical ventilation [median (interquartile range) 22 (9-72) h vs 49 (24-117) h, P = 0.007]. The total intensive care unit length of stay [6.9 (4.2-12.4) days vs 8.3 (5.3-13.2) days, P = 0.04] and the total hospital length of stay [17.3 (13.3-23.2) days vs 18.3 (15.1-23.6) days, P = 0.05] of the Down patients were also longer. Mortality was similar in the two groups before (3.58 vs 3.88%, P = 0.86) and after (5.4 vs 4.5%, P = 1.00) propensity matching. After propensity matching, there was no difference in the occurrence of adverse events. CONCLUSIONS: After propensity matching Down syndrome was not associated with increased mortality or complication rate following congenital cardiac surgery.

Postoperative differences between colonization and infection after pediatric cardiac surgery-a propensity matched analysis.

BACKGROUND: The objective of this study was to identify the postoperative risk factors associated with the conversion of colonization to postoperative infection in pediatric patients undergoing cardiac surgery. METHODS: Following approval from the Institutional Review Board, patient demographics, co-morbidities, surgery details, transfusion requirements, inotropic infusions, laboratory parameters and positive microbial results were recorded during the hospital stay, and the patients were divided into two groups: patients with clinical signs of infection and patients with only positive cultures but without infection during the postoperative period. Using propensity scores, 141 patients with infection were matched to 141 patients with positive microbial cultures but without signs of infection. Our database consisted of 1665 consecutive pediatric patients who underwent cardiac surgery between January 2004 and December 2008 at a single center. The association between the patient group with infection and the group with colonization was analyzed after propensity score matching of the perioperative variables. RESULTS: 179 patients (9.3%) had infection, and 253 patients (15.2%) had colonization. The occurrence of Gram-positive species was significantly greater in the colonization group (p=0.004). The C-reactive protein levels on the first and second postoperative days were significantly greater in the infection group (p=0.02 and p=0.05, respectively). The sum of all the positive cultures obtained during the postoperative period was greater in the infection group compared to the colonization group (p=0.02). The length of the intensive care unit stay (p<0.001) was significantly longer in the infection group compared to the control group. CONCLUSIONS: Based on our results, we uncovered independent relationships between the conversion of colonization to infection regarding positive S. aureus and bloodstream results, as well as significant differences between the two groups regarding postoperative C-reactive protein levels and white blood cell counts.