Michael J. Robertson

Outcomes associated with preoperative use of extracorporeal membrane oxygenation in children undergoing heart operation for congenital heart disease: a multi-institutional analysis.

There are very sparse data on patient outcomes related to the use of extracorporeal membrane oxygenation (ECMO) prior to heart operation in children with congenital heart disease. This study was designed to evaluate this association using the Pediatric Health Information System (PHIS) database.

Relationship between renal function and extracorporeal membrane oxygenation use: a single-center experience.

The effects of extracorporeal membrane oxygenation (ECMO) support on renal function in children with critical illness are unknown. The objective of this study was to investigate the impact of ECMO on renal function among children in different age groups. We performed a single-center retrospective observational study in critically ill children ≤ 18 years supported on ECMO for refractory cardiac or pulmonary failure (2006-2012). The patient population was divided into four age groups for the purpose of comparisons. The Acute Kidney Injury Networks (AKINs) validated, three-tiered staging system for acute kidney injury was used to categorize the degree of worsening renal function. Data on patient demographics, baseline characteristics, renal function parameters, dialysis, ultrafiltration, duration of mechanical cardiac support, and mortality were collected. Comparisons of baseline characteristics, duration of mechanical cardiac support, and renal function were made between the four age groups. During the study period, 311 patients qualified for inclusion, of whom 289 patients (94%) received venoarterial (VA) ECMO, 12 (4%) received venovenous (VV) ECMO, and 8 (3%) received both VV and VA ECMO. A total of 109 patients (36%) received ultrafiltration on ECMO, 58 (19%) received hemodialysis, and 51 (16%) received peritoneal dialysis. There was a steady and sustained improvement in renal function in all age groups during the ECMO run, with the maximum and longest-sustained improvement occurring in the oldest age group. Proportions of patients in different AKIN stages remained similar in the first 7 days after ECMO initiation. We demonstrate that renal dysfunction improves early after ECMO support. Irrespective of the underlying disease process or patient age, renal function improves in children with pulmonary or cardiac failure who are placed on ECMO.

Erratum to: Impact of varied center volume categories on volume–outcome relationship in children receiving ECMO for heart operations

To study the volume–outcome relationship among children receiving extracorporeal membrane oxygenation (ECMO), different studies from different databases use different volume categories. The objective of this study was to evaluate if different center volume categories impact the volume–outcome relationship among children receiving ECMO for heart operations. We performed a post hoc analysis of data from an existing national database, the Pediatric Health Information System. Centers were classified into five different volume categories using different cut-offs and different variables. Mortality rates were compared between the varied volume categories using a mixed effects logistic regression model after adjusting for patient- and center-level risk factors. Data collection included demographic information, baseline characteristics, pre-ECMO risk factors, operation details, patient diagnoses, and center data. In unadjusted analysis, there was a significant relationship between center volume and mortality, with low-and medium-volume centers associated with higher mortality rates compared to high-volume centers in all volume categories, except the hierarchical clustering volume category. In contrast, there was no significant association between center-volume and mortality among all volume categories in adjusted analysis. We concluded that high-volume centers were not associated with improved outcomes for the majority of the categorization schemes despite using different cut-offs and different variables for volume categorization.

Association of haematocrit and red blood cell transfusion with outcomes in infants with shunt-dependent pulmonary blood flow and univentricular physiology.

BACKGROUND The aim of this study was to investigate the association between red blood cell (RBC) transfusion and haematocrit values with outcomes in infants with univentricular physiology undergoing surgery for a modified Blalock-Taussig shunt. MATERIAL AND METHODS This study included infants ≤ 2 months of age who underwent modified Blalock-Taussig shunt surgery at the Arkansas Childrens Hospital (2006-2012). Infants undergoing a Norwood operation or Damus-Kaye-Stansel operation with modified Blalock-Taussig shunt were excluded. Demographics, pre-operative, operative, daily laboratory data, and post-operative variables were collected. We studied the association between haematocrit and blood transfusion with a composite clinical outcome. Multivariable logistic regression models were fitted to study the probability of study outcomes as a function of haematocrit values and RBC transfusions after operation. RESULTS Seventy-three patients qualified for inclusion. All study patients received blood transfusion within the first 48 hours after heart surgery. The median haematocrit was 44.3 (interquartile range [IQR] 42.5-46.2), and the median volume of RBC transfused was 28 mL/kg (IQR, 10-125) in the first 14 days after surgery. The overall in-hospital mortality rate was 13.6% (10 patients). A multivariable analysis adjusted for risk factors, including weight, prematurity, cardiopulmonary bypass and postoperative need for nitric oxide and dialysis, revealed no association between haematocrit values and RBC transfusion with the composite clinical outcome. DISCUSSION We did not find an association between higher haematocrit values and increasing RBC transfusions with improved outcomes in infants with shunt-dependent pulmonary blood flow and univentricular physiology. The power of our study was small, which prevents any strong statement on this lack of association. Future multi-centre, randomised controlled trials are needed to investigate this topic in further detail.

329: IMPACT OF VARIED CENTER VOLUME CATEGORIES ON MORTALITY IN CHILDREN RECEIVING ECMO FOR HEART DISEASE

Crit Care Med 2015 • Volume 43 • Number 12 (Suppl.) Living (ADLs) and Instrumental Activities of Daily Living (IADLs) and followed patients until death or hospital discharge. Results: In our cohort of 84 patients (mean (standard deviation, SD) age 57.4 (18.6), 32 had at least one impairment in ADL, with a median (interquartile range IQR) of 3 (1.5–4.5). Of the 52 without impairment in ADLs, 10 reported ≥ 1 impairment in IADL; 42 were completely independent. Patients with functional impairment were older (mean age (SD) 63.3 (19.9) versus 57.5 (15.3) in those without impairment, p=0.003); more likely to be admitted from a nursing facility (30.9 % versus 0%, p=0.002) and had higher Comorbidity Index (median (IQR) 3 (1–4) versus 1.5 (1–3), p=0.041). Patients with functional impairment did not appear to have significantly higher severity of illness on presentation to the ICU (mean APACHE II score (SD) 63.0 (23.4) versus 57.1 (20.7) in those without functional impairment, p=0.22). Of the 84 patients in the sample, 17 died in the hospital (20.5% hospital mortality). Pre-hospital functional impairment was not significantly associated with hospital mortality (unadjusted Odds Ratio (95% Confidence Interval (CI) 1.52 (0.51–4.47, p=0.449) nor was it associated with discharge to a skilled facility in those who were admitted from home (n=71) (Odds ratio 1.43 (95% CI 0.55–3.70, p=0.47). Conclusions: In this sample of critically ill adults, pre-hospital functional impairment was prevalent but not significantly associated with hospital mortality or discharge location. Other approaches for identifying critically ill patients at high risk of short-term outcomes are needed.