Inaccuracy of a continuous arterial pressure waveform monitor when used for congenital cardiac catheterization.

OBJECTIVE: To determine the accuracy of a continuous cardiac output monitor (FloTrac sensor) for measuring cardiac index in children with congenital heart disease undergoing cardiac catheterization. Cardiac index is a critical hemodynamic parameter measured during catheterizations in children with congenital heart disease. This has been challenging to measure accurately and many clinicians rely on predictive equations for calculating cardiac index. DESIGN: Prospective, nonrandomized trial. SETTING: Tertiary care congenital heart center. PATIENTS: Consecutive participants ≤18 years old undergoing clinically indicated cardiac catheterizations from September 2014 through August 2015. INTERVENTIONS: Oxygen consumption was measured using the Vmax Encore 229 monitor attached to the ventilator circuit. The FloTrac transducer with third generation software was connected to a pigtail catheter in the descending aorta and cardiac index was obtained. OUTCOME MEASURES: Cardiac index by the Fick equation using measured oxygen consumption was compared to cardiac index from the FloTrac sensor using paired t-test and Bland-Altman analysis. RESULTS: 39 participants (median age 5.1 years, 1.5-18.3, 64% female) were studied. Cardiac index by FloTrac was higher than cardiac index by Fick (6.4 ± 3.4 vs 3.7 ± 1.2 L/min/m2 , P < .001). Bland-Altman analysis showed a consistent overestimation of cardiac index by FloTrac which worsened as cardiac index increased (mean bias 2.7 L/min/m2 , 95% limits of agreement -4.2, 9.5). CONCLUSIONS: The results of this study show that the FloTrac sensor provides cardiac index measures which are not accurate enough to justify use in children with congenital heart disease undergoing catheterization. Further studies may allow for modifications of the algorithms to obtain more accurate cardiac index in this population.

Nurses' Attitudes Toward Clinical Research: Experience of the Therapeutic Hypothermia After Pediatric Cardiac Arrest Trials.

OBJECTIVES: To understand factors affecting nurses' attitudes toward the Therapeutic Hypothermia After Pediatric Cardiac Arrest trials and association with approach/consent rates. DESIGN: Cross-sectional survey of pediatric/cardiac intensive care nurses' perceptions of the trials. SETTING: Study was conducted at 16 of 38 self-selected study sites. SUBJECTS: Pediatric and cardiac intensive care nurses. MEASUREMENTS AND MAIN RESULTS: The primary outcome was the proportion of nurses with positive perceptions, as defined by agree or strongly agree with the statement "I am happy to take care of a Therapeutic Hypothermia after Pediatric Cardiac Arrest patient". Associations between perceptions and study approach/consent rates were also explored. Of 2,241 nurses invited, 1,387 (62%) completed the survey and 77% reported positive perceptions of the trials. Nurses, who felt positively about the scientific question, the study team, and training received, were more likely to have positive perceptions of the trials (p < 0.001). Nurses who had previously cared for a research patient had significantly more positive perceptions of Therapeutic Hypothermia After Pediatric Cardiac Arrest compared with those who had not (79% vs 54%; p < 0.001). Of the 754 nurses who cared for a Therapeutic Hypothermia After Pediatric Cardiac Arrest patient, 82% had positive perceptions, despite 86% reporting it required more work. Sixty-nine percent believed that hypothermia reduces brain injury and mortality; sites had lower consent rates when their nurses believed that hypothermia was beneficial. Institution-specific approach rates were positively correlated with nurses' perceptions of institutional support for the trial (r = 0.54; p = 0.04), ICU support (r = 0.61; p = 0.02), and the importance of conducting the trial in children (r = 0.61; p = 0.01). CONCLUSIONS: The majority of nurses had positive perceptions of the Therapeutic Hypothermia After Pediatric Cardiac Arrest trials. Institutional, colleague, and study team support and training were contributing factors. Despite increased work, nurses remained enthusiastic demonstrating that studies with intensive bedside nursing procedures are feasible. Institutions whose nurses believed hypothermia was beneficial had lower consent rates, suggesting that educating nurses on study rationale and equipoise may enhance study participation.

Clinical characteristics associated with postoperative intestinal epithelial barrier dysfunction in children with congenital heart disease.

OBJECTIVE: Children with congenital heart disease have loss of intestinal epithelial barrier function, which increases their risk for postoperative sepsis and organ dysfunction. We do not understand how postoperative cardiopulmonary support or the inflammatory response to cardiopulmonary bypass might alter intestinal epithelial barrier function. We examined variation in a panel of plasma biomarkers to reflect intestinal epithelial barrier function (cellular and paracellular) after cardiopulmonary bypass and in response to routine ICU care. DESIGN: Prospective cohort. SETTING: University medical center cardiac ICU. PATIENTS: Twenty children aged between newborn and 18 years undergoing repair or palliation of congenital heart disease with cardiopulmonary bypass. INTERVENTIONS: We measured baseline and repeated plasma intestinal fatty acid-binding protein, citrulline, claudin 3, and dual sugar permeability testing to reflect intestinal epithelial integrity, epithelial function, paracellular integrity, and paracellular function, respectively. We measured baseline and repeated plasma proinflammatory (interleukin-6, tumor necrosis factor-α, and interferon-γ) and anti-inflammatory (interleukin-4 and interleukin-10) cytokines, known to modulate intestinal epithelial barrier function in murine models of cardiopulmonary bypass. MEASUREMENTS AND MAIN RESULTS: All patients had abnormal baseline intestinal fatty acid-binding protein concentrations (mean, 3,815.5 pg/mL; normal, 41-336 pg/mL). Cytokine response to cardiopulmonary bypass was associated with early, but not late, changes in plasma concentrations of intestinal fatty acid-binding protein 2 and citrulline. Variation in biomarker concentrations over time was associated with aspects of ICU care indicating greater severity of illness: claudin 3, intestinal fatty acid-binding protein 2, and dual sugar permeability test ratio were associated with symptoms of feeding intolerance (p < 0.05), whereas intestinal fatty acid-binding protein was positively associated with vasoactive-inotrope score (p = 0.04). Citrulline was associated with larger arteriovenous oxygen saturation difference (p = 0.04) and had a complex relationship with vasoactive-inotrope score. CONCLUSIONS: Children undergoing cardiopulmonary bypass for repair or palliation of congenital heart disease are at risk for intestinal injury and often present with evidence for loss of intestinal epithelial integrity preoperatively. Greater severity of illness requiring increased cardiopulmonary support rather than the inflammatory response to cardiopulmonary bypass seems to mediate late postoperative intestinal epithelial barrier function.