Delirium in a Tertiary Pediatric Cardiac Intensive Care Unit: Risk Factors and Outcomes.

OBJECTIVE: Delirium is an increasingly recognized hospital complication associated with poorer outcomes in critically ill children. We aimed to evaluate risk factors for screening positive for delirium in children admitted to a pediatric cardiac intensive care unit (CICU) and to examine the association between duration of positive screening and in-hospital outcomes. STUDY DESIGN: Retrospective cohort study in a single-center quaternary pediatric hospital CICU evaluating children admitted from March 2014-October 2016 and screened for delirium using the Cornell Assessment of Pediatric Delirium. Statistical analysis used multivariable logistic and linear regression. RESULTS: Among 942 patients with screening data (98% of all admissions), 67% of patients screened positive for delirium. On univariate analysis, screening positive was associated with younger age, single ventricle anatomy, duration of mechanical ventilation, continuous renal replacement therapy, extracorporeal life support, and surgical complexity, as well as higher average total daily doses of benzodiazepines, opioids, and dexmedetomidine. On multivariable analysis, screening positive for delirium was independently associated with age <2 years, duration of mechanical ventilation, and greater than the median daily doses of benzodiazepine and opioid. In addition to these factors, duration of screening positive was also independently associated with higher STAT category (3-5) or medical admission, organ failure, acute kidney injury (AKI), and higher dexmedetomidine exposure. Duration of positive delirium screening was associated with both increased CICU and hospital length of stay (each additional day of positive screening was associated with a 3% longer CICU stay [95% CI = 1%-6%] and 2% longer hospital stay [95% CI = 0%-4%]). CONCLUSIONS: Screening positive for delirium is common in the pediatric CICU and is independently associated with prolonged intensive care unit (ICU) and hospital stay. Longer duration of mechanical ventilation and higher sedative doses are independent risk factors for screening positive for delirium. Efforts aimed at reducing these exposures may decrease the burden of delirium in this population.

Younger age remains a risk factor for prolonged length of stay after bidirectional cavopulmonary anastomosis.

OBJECTIVE: This study sets out to determine the influence of age at the time of surgery as a risk factor for post-operative length of stay after bidirectional cavopulmonary anastomosis. METHODS: All patients undergoing a Glenn procedure between January 2010 and July 2015 were included in this retrospective cohort study. Demographic data were examined. Standard descriptive statistics was used. A univariable analysis was conducted using the appropriate test based on data distribution. A propensity score for balancing the group difference was included in the multi-variable analysis, which was then completed using predictors from the univariable analysis that achieved significance of p<0.1. RESULTS: Over the study period, 50 patients met the inclusion criteria. Patients were separated into two cohorts of ⩾4 months (28 patients) and <4 months (22 patients). Other than height and weight, the two cohorts were indistinguishable in their pre-operative saturation, medications, catheterisation haemodynamics, atrioventricular valve regurgitation, and ventricular function. After adjusting group differences, younger age was associated with longer post-operative length of hospitalisation - adjusted mean 15 (±2.53) versus 8 (±2.15) days (p=0.03). In a multi-variable regression analysis, in addition to ventricular dysfunction (ß coefficient=8.8, p=0.05), Glenn procedures performed before 4 months were independently associated with longer length of stay (ß coefficient=-6.9, p=0.03). CONCLUSION: We found that Glenn procedures performed after 4 months of age had shorter post-operative length of stay when compared to a younger cohort. These findings suggest that balancing timing of surgery to decrease the inter-stage period should take into consideration differences in post-operative recovery with earlier operations.

Postoperative feeding problems in patients with tetralogy of Fallot, pulmonary atresia, and major aortopulmonary collaterals undergoing unifocalisation surgery.

BACKGROUND: Patients with tetralogy of Fallot, pulmonary atresia, and major aortopulmonary collaterals are at risk for prolonged hospitalisation after unifocalisation. Feeding problems after congenital heart surgery are associated with longer hospital stay. We sought to determine the impact of baseline, intra-operative, and postoperative factors on the need for feeding tube use at the time of discharge. METHODS: We included patients with the aforementioned diagnosis undergoing unifocalisation from ages 3 months to 4 years from 2010 to 2016. We excluded patients with a pre-existing feeding tube. Patients discharged with an enteric tube were included in the feeding tube group. We compared the feeding tube group with the non-feeding-tube group by univariable and multi-variable logistic regression. RESULTS: Of the 56 patients studied, 41% used tube feeding. Median age and weight z-score were similar in the two groups. A chromosome 22q11 deletion was associated with the need for a feeding tube (22q11 deletion in 39% versus 15%, p=0.05). Median cardiopulmonary bypass time in the feeding tube group was longer (335 versus 244 minutes, p=0.04). Prolonged duration of mechanical ventilation was associated with feeding tube use (48 versus 3%, p=0.001). On multi-variable analysis, prolonged mechanical ventilation was associated with feeding tube use (odds ratio 10.2, 95% confidence intervals 1.6; 63.8). CONCLUSION: Among patients with tetralogy of Fallot, pulmonary atresia, and major aortopulmonary collaterals who were feeding by mouth before surgery, prolonged mechanical ventilation after unifocalisation surgery was associated with feeding tube use at discharge. Anticipation of feeding problems in this population and earlier feeding tube placement may reduce hospital length of stay.

Association of dead space ventilation and prolonged ventilation after repair of tetralogy of Fallot with pulmonary atresia.

BACKGROUND: We set out to determine whether patients with tetralogy of Fallot with pulmonary atresia and major aortopulmonary collateral arteries (TOF/PA/MAPCA) are at risk for elevated dead space ventilation fraction (VD/VT), and whether this is associated with prolonged mechanical ventilation. We hypothesized that elevated VD/VT (>20%) in the first 24 hours after unifocalization surgery is associated with increased risk for prolonged mechanical ventilation (>7 days). METHODS: All patients with TOF/PA/MAPCA undergoing unifocalization surgery between January 2003 and December 2015 were included in this study. Average VD/VT was calculated over the first 24 hours after surgery. Demographic and surgical data were collected. Outcome data included duration of mechanical ventilation. Patients were separated into 2 groups: elevated VD/VT and normal DVSF. Groups were compared using the Student t test, Wilcoxon rank-sum test, and χ2 test. Univariable and multivariable regression analyses were performed with VD/VT as a continuous variable to test for association. RESULTS: Of the 265 included patients, 127 (48%) had an elevated VD/VT. The 2 groups did not differ significantly in any demographic characteristic. Patients with an elevated VD/VT had longer cardiopulmonary bypass times (P = .03), were more likely to have delayed sternal closure, and more likely to have prolonged respiratory failure (odds ratio, 2.2; 95% confidence interval, 1.2-4.0; P = .007). The percent VD/VT was associated with duration of mechanical ventilation in univariable (P < .001) and multivariable (P < .001) regression analyses when controlled for age, weight and bypass time. CONCLUSIONS: Elevated postoperative VD/VT is associated with prolonged mechanical ventilation in patients with TOF/PA/MAPCA following unifocalization. Elevated postoperative VD/VT may be an early indicator of patients who will require prolonged duration of mechanical ventilation, allowing optimization of medical management to promote better outcomes.

Bronchoscopy in children with tetralogy of fallot, pulmonary atresia, and major aortopulmonary collaterals.

OBJECTIVE: Children with Tetralogy of Fallot, Pulmonary Atresia, and Major Aortopulmonary Collaterals (TOF/PA/MAPCAs) undergoing unifocalization surgery are at risk for developing more postoperative respiratory complications than children undergoing other types of congenital heart surgery. Bronchoscopy is used in the perioperative period for diagnostic and therapeutic purposes. In this study, we describe bronchoscopic findings and identify factors associated with selection for bronchoscopy. DESIGN: Retrospective case-control. PATIENTS AND METHODS: All patients with TOF/PA/MAPCAs who underwent unifocalization surgery from September 2005 through March 2016 were included. Patients who underwent bronchoscopy in the perioperative period were compared to a randomly selected cohort of 172 control patients who underwent unifocalization without bronchoscopy during the study period. RESULTS: Forty-three children underwent perioperative bronchoscopy at a median of 9 days postoperatively. Baseline demographics were similar in bronchoscopy patients and controls. Patients who underwent bronchoscopy were more likely to have a chromosome 22q11 deletion and were more likely have undergone unifocalization surgery without intracardiac repair. These patients had a longer duration of mechanical ventilation, ICU duration, and length of hospitalization. Abnormalities were detected on bronchoscopy in 35 patients (81%), and 20 (35%) of bronchoscopy patients underwent a postoperative intervention related to abnormalities identified on bronchoscopy. CONCLUSION: Bronchoscopy is a useful therapeutic and diagnostic instrument for children undergoing unifocalization surgery, capable of identifying abnormalities leading to an additional intervention in over one third of patients. Special attention should be given to children with a 22q11 deletion to expedite diagnosis and intervention for possible airway complications.

Institution of Veno-arterial Extracorporeal Membrane Oxygenation Does Not Lead to Increased Wall Stress in Patients with Impaired Myocardial Function.

The effect of veno-arterial extracorporeal membrane oxygenation (VA ECMO) on wall stress in patients with cardiomyopathy, myocarditis, or other cardiac conditions is unknown. We set out to determine the circumferential and meridional wall stress (WS) in patients with systemic left ventricles before and during VA ECMO. We established a cohort of patients with impaired myocardial function who underwent VA ECMO therapy from January 2000 to November 2013. Demographic and clinical data were collected and inotropic score calculated. Measurements were taken on echocardiograms prior to the initiation of VA ECMO and while on full-flow VA ECMO, in order to derive wall stress (circumferential and meridional), VCFc, ejection fraction, and fractional shortening. A post hoc sub-analysis was conducted, separating those with pulmonary hypertension (PH) and those with impaired systemic output. Thirty-three patients met inclusion criteria. The patients' median age was 0.06 years (range 0-18.7). Eleven (33%) patients constituted the organ failure group (Gr2), while the remaining 22 (66%) patients survived to discharge (Gr1). WS and all other echocardiographic measures were not different when comparing patients before and during VA ECMO. Ejection and shortening fraction, WS, and VCFc were not statistically different comparing the survival and organ failure groups. The patients' position on the VCFc-WS curve did not change after the initiation of VA ECMO. Those with PH had decreased WS as well as increased EF after ECMO initiation, while those with impaired systemic output showed no difference in those parameters with initiation of ECMO. The external workload on the myocardium as indicated by WS is unchanged by the institution of VA ECMO support. Furthermore, echocardiographic measures of cardiac function do not reflect the changes in ventricular performance inherent to VA ECMO support. These findings are informative for the interpretation of echocardiograms in the setting of VA ECMO. ECMO may improve ventricular mechanics in those with PH as the primary diagnosis.

Acute Kidney Injury in Patients Undergoing the Extracardiac Fontan Operation With and Without the Use of Cardiopulmonary Bypass.

OBJECTIVES: To describe the prevalence and risk factors for acute kidney injury in patients undergoing the extracardiac Fontan operation with and without cardiopulmonary bypass, and to determine whether acute kidney injury is associated with duration of mechanical ventilation, cardiovascular ICU and hospital postoperative length of stay, and early mortality. DESIGN: Single-center retrospective cohort study. SETTING: Pediatric cardiovascular ICU, university-affiliated children's hospital. PATIENTS: Patients with a preoperative creatinine before undergoing first-time extracardiac Fontan between January 1, 2004, and April 30, 2012. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Acute kidney injury occurred in 55 of 138 patients (39.9%), including 41 (29.7%) with stage 1, six (4.4%) with stage 2, and eight (5.8%) with stage 3 acute kidney injury. Cardiopulmonary bypass was strongly associated with a higher risk of any acute kidney injury (adjusted odds ratio, 4.8 [95% CI, 1.4-16.0]; p = 0.01) but not stage 2/3 acute kidney injury. Lower renal perfusion pressure on the day of surgery (postoperative day, 0) was associated with a higher risk of stage 2/3 acute kidney injury (adjusted odds ratio, 1.2 [95% CI, 1.0-1.5]; p = 0.03). Higher vasoactive-inotropic score on postoperative day 0 was associated with a higher risk for stage 2/3 acute kidney injury (adjusted odds ratio, 1.9 [95% CI, 1.0-3.4]; p = 0.04). Stage 2/3 acute kidney injury was associated with longer cardiovascular ICU length of stay (mean, 7.3 greater d [95% CI, 3.4-11.3]; p < 0.001) and hospital postoperative length of stay (mean, 6.4 greater d [95% CI, 0.06-12.5]; p = 0.04). CONCLUSIONS: Postoperative acute kidney injury in patients undergoing the extracardiac Fontan operation is common and is associated with lower postoperative renal perfusion pressure and higher vasoactive-inotropic score. Cardiopulmonary bypass was strongly associated with any acute kidney injury, although not stage 2/3 acute kidney injury. Stage 2/3 acute kidney injury is a compelling risk factor for longer cardiovascular ICU and hospital postoperative length of stay. Increased attention to and management of renal perfusion pressure may reduce postoperative acute kidney injury and improve outcomes.

Postoperative Outcomes of Children With Tetralogy of Fallot, Pulmonary Atresia, and Major Aortopulmonary Collaterals Undergoing Reconstruction of Occluded Pulmonary Artery Branches.

BACKGROUND: Patients with tetralogy of Fallot, pulmonary atresia, and major aortopulmonary collaterals (TOF/PA/MAPCAs) undergoing unifocalization surgery are at risk for prolonged postoperative respiratory failure. We sought to understand whether patients undergoing reconstruction and incorporation of occluded pulmonary arterial branches were at risk for worse postoperative outcomes. METHODS: We performed a retrospective chart review to identify patients who underwent unifocalization or unifocalization revision with incorporation of occluded pulmonary artery branches. Patients with and without occluded branches were compared, with a focus on clinical outcomes. RESULTS: We studied 92 patients who underwent unifocalization procedures between 2010 and 2014, 17 (18%) of whom underwent reconstruction of occluded pulmonary artery branches. Patients with occluded vessels were more likely to require staged unifocalization procedures, although more than two thirds of this cohort eventually underwent complete intracardiac repair. Durations of mechanical ventilation, intensive care, hospital stay, and the need for early reoperation were similar between the two groups. CONCLUSIONS: Occluded pulmonary arterial branches can be safely recruited into the pulmonary vasculature in patients with TOF/PA/MAPCAs without a significant difference in postoperative outcomes compared with patients who did not have an occluded branch. Incorporation of occluded branches may also facilitate ultimate complete intracardiac repair in this complex population of patients.