Michael Gaies

Vasoactive–inotropic score as a predictor of morbidity and mortality in infants after cardiopulmonary bypass*

Objective: Inotrope score has been proposed as a marker of illness severity after pediatric cardiac surgery despite a lack of data to support its use as such. The goal of this study was to determine the association between inotropic/vasoactive support and clinical outcome in infants after cardiac surgery. Design: Retrospective chart review. Setting: Dedicated pediatric cardiothoracic intensive care unit at an academic, tertiary care medical center. Patients: One hundred seventy-four patients 0 to 6 months of age admitted to the cardiothoracic intensive care unit after cardiac surgery with cardiopulmonary bypass between August 2007 and June 2008. Forty-three percent were neonates, and 39% had functional single ventricle physiology. Interventions: None. Measurements and Main Results: Hourly doses of all vasoactive medications were recorded for the first 48 hrs after admission to the cardiothoracic intensive care unit and a vasoactive–inotropic score was calculated. The maximum vasoactive–inotropic score level over the first 48 hrs was a good predictor of poor clinical outcome (death, cardiac arrest, mechanical circulatory support, renal replacement therapy, and/or neurologic injury). After controlling for diagnosis, high maximum vasoactive–inotropic score was strongly associated with a poor outcome with an adjusted odds ratio of 8.1 (95% confidence interval, 3.4–19.2; p < .001) compared with patients with a low maximum vasoactive–inotropic score. High vasoactive–inotropic score was also associated with prolonged cardiothoracic intensive care unit stay, duration of mechanical ventilation, and time to negative fluid balance. Conclusions: The amount of cardiovascular support in the first 48 hrs after congenital heart surgery with cardiopulmonary bypass predicts eventual morbidity and mortality in young infants. The degree of support is best characterized by a maximum vasoactive–inotropic score obtained during this period. The usefulness of vasoactive–inotropic score as an independent predictor of clinical outcome in infants after cardiac surgery may have important implications for future cardiothoracic intensive care unit research. (Pediatr Crit Care Med 2010; 11:234–238)

Fluid overload and fluid removal in pediatric patients on extracorporeal membrane oxygenation requiring continuous renal replacement therapy.

Objective:In pediatric patients, fluid overload at continuous renal replacement therapy initiation is associated with increased mortality. The aim of this study was to characterize the association between fluid overload at continuous renal replacement therapy initiation, fluid removal during continuous renal replacement therapy, the kinetics of fluid removal and mortality in a large pediatric population receiving continuous renal replacement therapy while on extracorporeal membrane oxygenation. Design:Retrospective chart review. Setting:Tertiary children’s hospital. Patients:Extracorporeal membrane oxygenation patients requiring continuous renal replacement therapy from July 2006 to September 2010. Interventions:None. Measurements and Main Results:Overall intensive care unit survival was 34% for 53 patients that were initiated on continuous renal replacement therapy while on extracorporeal membrane oxygenation during the study period. Median fluid overload at continuous renal replacement therapy initiation was significantly lower in survivors compared to nonsurvivors (24.5% vs. 38%, p = .006). Median fluid overload at continuous renal replacement therapy discontinuation was significantly lower in survivors compared to nonsurvivors (7.1% vs. 17.5%, p = .035). After adjusting for percent fluid overload at continuous renal replacement therapy initiation, age, and severity of illness, the change in fluid overload at continuous renal replacement therapy discontinuation was not significantly associated with mortality (p = .212). Models investigating the rates of fluid removal in different periods, age, severity of illness, and fluid overload at continuous renal replacement therapy initiation found that fluid overload at continuous renal replacement therapy initiation was the most consistent predictor of survival. Conclusions:Our data demonstrate an association between fluid overload at continuous renal replacement therapy initiation and mortality in pediatric patients receiving extracorporeal membrane oxygenation. The degree of fluid overload at continuous renal replacement therapy discontinuation is also associated with mortality, but appears to reflect the effect of fluid overload at initiation. Furthermore, correction of fluid overload to ⩽10% was not associated with improved survival. These results suggest that intervening prior to the development of significant fluid overload may be more clinically effective than attempting fluid removal after significant fluid overload has developed. Our findings suggest a role for earlier initiation of continuous renal replacement therapy in this population, and warrant further clinical studies.

Reforming Procedural Skills Training for Pediatric Residents: A Randomized, Interventional Trial

BACKGROUND: Pediatric housestaff are required to learn basic procedural skills and demonstrate competence during training. To our knowledge, an evidenced-based procedural skills curriculum does not exist. OBJECTIVE: To create, implement, and evaluate a modular procedural skills curriculum for pediatric residents. METHODS: A randomized, controlled trial was performed. Thirty-eight interns in the Boston Combined Residency Program who began their training in 2005 were enrolled and randomly assigned. Modules were created to teach residents bag-mask ventilation, venipuncture, peripheral intravenous catheter (PIV) insertion, and lumbar puncture skills. The curriculum was administered to participants in the intervention group during intern orientation. Interns in the control group learned procedural skills by usual methods. Subjects were evaluated by using a structured objective assessment on simulators immediately after the intervention and 7 months later. Success in performing live-patient procedures was self-reported by subjects. The primary outcome was successful performance of the procedure on the initial assessment. Secondary outcomes included checklist and knowledge examination scores, live-patient success, and qualitative assessment of the curriculum. RESULTS: Participants in the intervention group performed PIV placement more successfully than controls (79% vs 35%) and scored significantly higher on the checklist for PIV placement (81% vs 61%) and lumbar puncture (77% vs 68%) at the initial assessment. There were no differences between groups at month 7, and both groups demonstrated declining skills. There were no statistically significant differences in success on live-patient procedures. Those in the intervention group scored significantly higher on knowledge examinations. CONCLUSIONS: Participants in the intervention group were more successful performing certain simulated procedures than controls when tested immediately after receiving the curriculum but demonstrated declining skills thereafter. Future efforts must emphasize retraining, and residents must have sufficient opportunities to practice skills learned in a formal curriculum.

Early and Intermediate Outcome After Anatomic Repair of Congenitally Corrected Transposition of the Great Arteries

BACKGROUND Anatomic repair of congenitally corrected transposition of the great arteries has become a useful surgical strategy with potential advantages over conventional surgical repair. We describe early and intermediate outcomes after anatomic repair and analyze potential risk factors influencing these outcomes. METHODS A retrospective review was performed on all patients undergoing anatomic repair between January 1993 and January 2009. The primary outcome was in-hospital mortality. Variables potentially associated with outcome were identified a priori. Bivariate analyses were performed to determine the association between these variables and all outcome measures. RESULTS In 65 patients who underwent anatomic repair, 35 had Senning/arterial switch and 30 had Senning/Rastelli. Early and intermediate survival rates for Senning/arterial switch operations were 94% and 91%, respectively. Repairs were successful in patients with tricuspid regurgitation, left ventricular outflow obstruction, and left ventricular dysfunction. Predictors of outcome were not identified in this subset. Early and intermediate survival rates for Senning/Rastelli operations were 77% and 60%, respectively. Longer aortic cross-clamp (p = 0.03) and cardiopulmonary bypass times (p = 0.01) were associated with mortality. Ventricular septal defect enlargement was associated with surgical heart block (p < 0.01). Age, prior procedures, atrial-apical discordance, and tricuspid regurgitation were not associated with outcome. CONCLUSIONS Senning/arterial switch operations can be performed with excellent intermediate-term outcomes in patients with lesions previously thought to confer higher risk. Candidates for Senning/Rastelli procedures may be at increased risk for postoperative morbidity and mortality. More data are necessary to determine factors influencing outcome after anatomic repair.

Extracorporeal Cardiopulmonary Resuscitation (E-CPR) During Pediatric In-Hospital Cardiopulmonary Arrest Is Associated With Improved Survival to Discharge: A Report from the American Heart Association's Get With The Guidelines-Resuscitation (GWTG-R) Registry.

Background— Although extracorporeal cardiopulmonary resuscitation (E-CPR) can result in survival after failed conventional CPR (C-CPR), no large, systematic comparison of pediatric E-CPR and continued C-CPR has been reported. Methods and Results— Consecutive patients <18 years old with CPR events ≥10 minutes in duration reported to the Get With the Guidelines–Resuscitation registry between January 2000 and December 2011 were identified. Hospitals were grouped by teaching status and location. Primary outcome was survival to discharge. Regression modeling was performed, conditioning on hospital groups. A secondary analysis was performed with the use of propensity score matching. Of 3756 evaluable patients, 591 (16%) received E-CPR and 3165 (84%) received C-CPR only. Survival to hospital discharge and survival with favorable neurological outcome (Pediatric Cerebral Performance Category score of 1–3 or unchanged from admission) were greater for E-CPR (40% [237 of 591] and 27% [133 of 496]) versus C-CPR patients (27% [862 of 3165] and 18% [512 of 2840]). Odds ratios (ORs) for survival to hospital discharge and survival with favorable neurological outcome were greater for E-CPR versus C-CPR. After adjustment for covariates, patients receiving E-CPR had higher odds of survival to discharge (OR, 2.80; 95% confidence interval, 2.13–3.69; P<0.001) and survival with favorable neurological outcome (OR, 2.64; 95% confidence interval, 1.91–3.64; P<0.001) than patients who received C-CPR. This association persisted when analyzed by propensity score–matched cohorts (OR, 1.70; 95% confidence interval, 1.33–2.18; P<0.001; and OR, 1.78; 95% confidence interval, 1.31–2.41; P<0.001, respectively]. Conclusion— For children with in-hospital CPR of ≥10 minutes duration, E-CPR was associated with improved survival to hospital discharge and survival with favorable neurological outcome compared with C-CPR.

The quest to optimize neurodevelopmental outcomes in neonatal arch reconstruction: The perfusion techniques we use and why we believe in them

Major advances in surgical techniques and medical care have brought exciting change to the outcomes of children treated for complex congenital heart disease. Hypoplastic left heart syndrome, for example, was uniformly fatal only 30 years ago, but now has a 5-year survival of approximately 70%. Although the survival for those with surgically repaired complex congenital heart defects has markedly improved, associated morbidities remain high. The neurodevelopmental outcomes of infants and children requiring multiple cardiac operations in childhood are among the major concerns of those who care for patients with congenital heart disease. Deep hypothermic circulatory arrest (DHCA), an adjunctive surgical technique that requires cooling the patient to 18 C and ceasing all blood flow to the entire body including the brain, has until recently been the standard intraoperative procedure used to perform aortic arch reconstruction in infants and young children. The development of DHCA in the early 1970s was a breakthrough that allowed for the operative treatment of many lesions previously not amenable to repair in neonates. Unfortunately, although still a mainstay in congenital heart surgery, DHCA is associated with the potential for poor neurodevelopmental outcomes.

Hemorrhagic complications in pediatric cardiac patients on extracorporeal membrane oxygenation: an analysis of the Extracorporeal Life Support Organization Registry.

Objectives: To determine the prevalence of and risk factors for hemorrhagic complications in children with cardiac disease requiring extracorporeal membrane oxygenation. Design: Retrospective review of the Extracorporeal Life Support Organization Registry (2002–2013). Setting: Participating Extracorporeal Life Support Organization centers. Patients: Patients less than 18 years old on extracorporeal membrane oxygenation. Interventions: None. Measurements and Main Results: Of 21,845 patients requiring extracorporeal membrane oxygenation during the study period, 8,905 (41%) had cardiac disease, and 79% of whom (6,995) had cardiac surgery. Hemorrhagic complications occurred in 8,480 patients (39% of overall cohort), with higher rates in cardiac versus noncardiac patients (49% vs 32%; p < 0.0001) related to cannulation and surgical site bleeding. Cardiac surgical patients had higher rates of hemorrhage compared with cardiac medical patients (57% vs 38%; p < 0.0001), and cardiac patients with hemorrhage had higher extracorporeal membrane oxygenation mortality compared with those without (42% vs 22% in medical patients and 34% vs 20% in surgical patients; both p < 0.0001). In multivariable analysis in both the cardiac medical and surgical groups, hemorrhage risk was higher in children greater than 1 year old and in patients with longer extracorporeal membrane oxygenation duration. Additional independent risk factors for hemorrhage in cardiac surgical patients included pre-extracorporeal membrane oxygenation mediastinal exploration (odds ratio, 3.6; 95% CI, 2.1–6.3), Society of Thoracic Surgeons morbidity category 4–5 (odds ratio, 1.2; 95% CI, 1.03–1.5), cannulation less than 24 hours after surgery (odds ratio, 1.6; 95% CI, 1.3–1.9), and longer cardiopulmonary bypass time (≥ 282 min [upper quartile]; odds ratio, 1.5; 95% CI, 1.3–1.9). Conclusions: In this large, multicenter analysis, hemorrhagic complications occurred in nearly half of children with heart disease on extracorporeal membrane oxygenation and were associated with a significant mortality risk. Several factors were associated with hemorrhagic complications in cardiac surgical patients including pre-extracorporeal membrane oxygenation mediastinal exploration, greater surgical complexity, early postoperative cannulation, and longer bypass times. Whether these risks can be mitigated by modifying or delaying systemic anticoagulation requires further investigation.

Collaborative quality improvement in the cardiac intensive care unit: development of the Paediatric Cardiac Critical Care Consortium (PC4)

Despite many advances in recent years for patients with critical paediatric and congenital cardiac disease, significant variation in outcomes remains across hospitals. Collaborative quality improvement has enhanced the quality and value of health care across specialties, partly by determining the reasons for variation and targeting strategies to reduce it. Developing an infrastructure for collaborative quality improvement in paediatric cardiac critical care holds promise for developing benchmarks of quality, to reduce preventable mortality and morbidity, optimise the long-term health of patients with critical congenital cardiovascular disease, and reduce unnecessary resource utilisation in the cardiac intensive care unit environment. The Pediatric Cardiac Critical Care Consortium (PC4) has been modelled after successful collaborative quality improvement initiatives, and is positioned to provide the data platform necessary to realise these objectives. We describe the development of PC4 including the philosophical, organisational, and infrastructural components that will facilitate collaborative quality improvement in paediatric cardiac critical care.

Clinical Epidemiology of Extubation Failure in the Pediatric Cardiac ICU: A Report From the Pediatric Cardiac Critical Care Consortium

Objective: To describe the clinical epidemiology of extubation failure in a multicenter cohort of patients treated in pediatric cardiac ICUs. Design: Retrospective cohort study using prospectively collected clinical registry data. Setting: Pediatric Cardiac Critical Care Consortium registry. Patients: All patients admitted to the CICU at Pediatric Cardiac Critical Care Consortium hospitals. Interventions: None. Measurements and Main Results: Analysis of all mechanical ventilation episodes in the registry from October 1, 2013, to July 31, 2014. The primary outcome of extubation failure was reintubation less than 48 hours after planned extubation. Repeated-measures analysis using generalized estimating equations to account for within patient and center correlation was performed to identify risk factors for extubation failure. Adjusted extubation failure rates for each hospital were calculated using logistic regression controlling for patient factors. Of 1,734 mechanical ventilation episodes (1,478 patients at eight hospitals) ending in a planned extubation, there were 100 extubation failures (5.8%). In multivariable analysis, only longer duration of mechanical ventilation was significantly associated with extubation failure (p = 0.01); the failure rate was 4% when ventilated less than 24 hours, 9% after 24 hours, and 13% after 7 days. For 503 patients intubated and extubated in the cardiac operating room, 15 patients (3%) failed extubation within 48 hours (12 within 24 hr). Case-mix-adjusted extubation failure rates ranged from 1.1% to 9.8% across hospitals. Patients failing extubation had greater median cardiac ICU length of stay (15 vs 3 d; p < 0.001) and in-hospital mortality (7.9 vs 1.2%; p < 0.001). Conclusions: Though extubation failure is uncommon overall, there may be opportunities to improve extubation readiness assessment in patients ventilated more than 24 hours. These data suggest that extubation in the operating room after cardiac surgery can be done with a low failure rate. We observed variation in extubation failure rates across hospitals, and future investigation must elucidate the optimal strategies of high-performing centers to reduce ventilation time while limiting extubation failures.

Personnel and unit factors impacting outcome after cardiac arrest in a dedicated pediatric cardiac intensive care unit

Objective: To assess the impact of personnel and unit factors on outcome from cardiac arrest in a dedicated pediatric cardiac intensive care unit. Design: Retrospective medical record review. Setting: Dedicated cardiac intensive care unit at a quaternary academic children’s hospital. Patients: Children and young adults who had cardiac arrest while cared for in the pediatric cardiac intensive care unit from January 1, 2006, to December 31, 2008. Interventions: None. Measurements and Main Results: One hundred two index cardiac arrests over a 3-yr period in our pediatric cardiac intensive care unit were reviewed. We defined successful resuscitation as either return of spontaneous circulation or successful cannulation to extracorporeal membrane oxygenation. Differences in resuscitation rates were assessed across categorical systems variables using logistic regression. The rate of successful resuscitation was 84% (return of spontaneous circulation 74%, extracorporeal membrane oxygenation 10%). Survival to hospital discharge was 48% for patients who had a cardiac arrest. 11% of arrests during the week and 31% during weekends (odds ratio 3.8; 95% confidence interval 1.2–11.5) were not successfully resuscitated. Unsuccessful resuscitation was significantly more likely when the primary nurse had <1 yr of experience in the pediatric cardiac intensive care unit (50% <1 yr vs. 13% >1 yr; odds ratio 6.8; confidence interval 1.5–31.0). Cardiac arrest on a weekend day and <1-yr pediatric cardiac intensive care unit nursing experience were also associated with unsuccessful resuscitation in a multivariable model. Resuscitation outcomes were similar when senior intensive care unit attending physicians were on-call at the time of arrest compared with other intensive care unit staff (17% unsuccessful vs. 15%; odds ratio 1.2; confidence interval 0.4–3.7). Arrests where the attending physician was present at the onset resulted in unsuccessful resuscitation 18% of the time vs. 14% for events where the attending was not present (odds ratio 1.3; confidence interval 0.5–3.9). Conclusions: Our data suggest that personnel and unit factors may impact outcome after cardiac arrest in a pediatric cardiac intensive care unit. Weekend arrests and less experience of the primary nurse were risk factors for unsuccessful resuscitation. Neither presence at arrest onset nor experience of the attending cardiac intensivist was associated with outcome.