Blood pressure variability during pediatric cardiac surgery is associated with acute kidney injury.

BACKGROUND: Blood pressure variability (BPV), defined as the degree of variation between discrete blood pressure readings, is associated with poor outcomes in acute care settings. Acute kidney injury (AKI) is a common and serious postoperative complication of cardiac surgery with cardiopulmonary bypass (CPB) in children. No studies have yet assessed the association between intraoperative BPV during cardiac surgery with CPB and the development of AKI in children. METHODS: A retrospective chart review of children undergoing cardiac surgery with CPB was performed. Intraoperative BPV was calculated using average real variability (ARV) and standard deviation (SD). Multiple regression models were used to examine the association between BPV and outcomes of AKI, hospital and intensive care unit (PICU) length of stay, and length of mechanical ventilation. RESULTS: Among 231 patients (58% males, median age 8.6 months) reviewed, 51.5% developed AKI (47.9% Stage I, 41.2% Stage II, 10.9% Stage III). In adjusted models, systolic and diastolic ARV were associated with development of any stage AKI (OR 1.40, 95% CI 1.08-1.8 and OR 1.4, 95% CI 1.05-1.8, respectively). Greater diastolic SD was associated with longer PICU length of stay (ß 0.94, 95% CI 0.62-1.2). When stratified by age, greater systolic ARV and SD were associated with AKI in infants ≤ 12 months, but there was no relationship in children > 12 months. CONCLUSIONS: Greater BPV during cardiac surgery with CPB was associated with development of postoperative AKI in infants, suggesting that BPV is a potentially modifiable risk factor for AKI in this high-risk population.

Sedation Management in Children Supported on Extracorporeal Membrane Oxygenation for Acute Respiratory Failure.

OBJECTIVES: To describe sedation management in children supported on extracorporeal membrane oxygenation for acute respiratory failure. DESIGN: Secondary analysis of prospectively collected data from a multicenter randomized trial of sedation (Randomized Evaluation of Sedation Titration for Respiratory Failure). SETTING: Twenty-one U.S. PICUs. PATIENTS: One thousand two hundred fifty-five children, 2 weeks to 17 years old, with moderate/severe pediatric acute respiratory distress syndrome. INTERVENTIONS: Sedation managed per usual care or Randomized Evaluation of Sedation Titration for Respiratory Failure protocol. MEASUREMENTS AND MAIN RESULTS: Sixty-one Randomized Evaluation of Sedation Titration for Respiratory Failure patients (5%) with moderate/severe pediatric acute respiratory distress syndrome were supported on extracorporeal membrane oxygenation, including 29 managed per Randomized Evaluation of Sedation Titration for Respiratory Failure protocol. Most extracorporeal membrane oxygenation patients received neuromuscular blockade (46%) or were heavily sedated with State Behavioral Scale scores -3/-2 (34%) by extracorporeal membrane oxygenation day 3. Median opioid and benzodiazepine doses on the day of cannulation, 0.15 mg/kg/hr (3.7 mg/kg/d) and 0.11 mg/kg/hr (2.8 mg/kg/d), increased by 36% and 58%, respectively, by extracorporeal membrane oxygenation day 3. In the 41 patients successfully decannulated prior to study discharge, patients were receiving 0.40 mg/kg/hr opioids (9.7 mg/kg/d) and 0.39 mg/kg/hr benzodiazepines (9.4 mg/kg/d) at decannulation, an increase from cannulation of 108% and 192%, respectively (both p < 0.001). Extracorporeal membrane oxygenation patients experienced more clinically significant iatrogenic withdrawal than moderate/severe pediatric acute respiratory distress syndrome patients managed without extracorporeal membrane oxygenation support (p < 0.001). Compared to extracorporeal membrane oxygenation patients managed per Randomized Evaluation of Sedation Titration for Respiratory Failure protocol, usual care extracorporeal membrane oxygenation patients received more opioids during the study period (mean cumulative dose of 183.0 vs 89.8 mg/kg; p = 0.02), over 6.5 greater exposure days (p = 0.002) with no differences in wakefulness or agitation. CONCLUSIONS: In children, the initiation of extracorporeal membrane oxygenation support is associated with deep sedation, substantial sedative exposure, and increased frequency of iatrogenic withdrawal syndrome. A standardized, goal-directed, nurse-driven sedation protocol may help mitigate these effects.

Nosocomial Bloodstream Infections in Patients Receiving Extracorporeal Life Support: Variability in Prevention Practices: A Survey of the Extracorporeal Life Support Organization Members.

Nosocomial blood stream infections (BSIs) increase both the morbidity and the mortality of patients receiving extracorporeal life support (ECLS). The aim of this study was to identify common practices for blood stream infection prevention among national Extracorporeal Membrane Oxygenation (ECMO) programs. An electronic survey that comprised of a 16-item questionnaire was sent out to all ECMO program directors and coordinators within the United States that are part of the Extracorporeal Life Support Organization (ELSO) registry. A total of 152 institutions in 40 states were surveyed, with 85 (55%) responses. One-quarter of the institutions responded that an ECMO infection-prevention bundle or checklist was used during the cannulation. Less than half responded that an ECMO infection-prevention bundle or checklist was used for cannula maintenance, although a majority (82.9%) of institutions responded that a "standard approach to cannula dressings" was used. Half of the respondents reported antimicrobial prophylaxis was routinely prescribed for patients on ECMO, although specific regimens varied widely. Of the institutions, 34.2% reported sending daily blood cultures as part of routine surveillance. Smaller programs were more likely to send daily surveillance blood cultures (58.8%, P < .01). We found no clear consensus on practices used to prevent BSI in patients receiving ECMO.

Acute Kidney Injury in Neonates in the PICU.

OBJECTIVES: Acute kidney injury is an independent risk factor for morbidity and mortality in critically ill children in the PICU. Neonates are a particularly vulnerable subgroup regarding acute kidney injury. The objectives were to define the prevalence of acute kidney injury to assess independent risk factors, for the development of acute kidney injury, and to determine the impact of acute kidney injury on outcomes in critically ill neonates without history of cardiac surgery. DESIGN: A retrospective study of neonates (≤ 28 d old and ≥ 32 wk of gestational age) admitted to a tertiary PICU was conducted. Acute kidney injury was classified using the Kidney Disease: Improving Global Outcomes definition. SETTING: PICU in a tertiary children's hospital. PATIENTS: A total of 80 neonates (62% male neonates) with a median gestational age of 38 weeks (interquartile range, 37-39 wk) were reviewed. INTERVENTION: None. MEASUREMENT AND MAIN RESULTS: Acute kidney injury was found in 35% (n = 28) of neonates. Fourteen (50%) reached stage I, 8 (29%) stage II, and 6 (21%) stage III acute kidney injury. Younger age was associated with acute kidney injury (p = 0.016; odds ratio, 0.93; CI, 0.88-0.98). In regression analysis adjusted for age and gender, bacteremia (p = 0.014; odds ratio, 5.4; CI, 1.4-20.4) and maximum sodium concentration (p = 0.02; odds ratio, 1.12; CI, 1.02-1.24) were associated with acute kidney injury. Mortality (p = 0.03) and length of mechanical ventilation (p = 0.001) were significantly higher in neonates with acute kidney injury compared with those without acute kidney injury. In an adjusted regression model, stages 2 and 3 combined were associated with increased mortality (p = 0.02; odds ratio, 5.64; CI, 1.33-23.8), length of ventilation (p = 0.016; ß, 12.2; CI, 2.39-22.0), and length of stay (p = 0.049; ß, 12.2; CI, 0.073-24.3). CONCLUSIONS: Acute kidney injury is common in neonates not requiring cardiac surgery and is associated with increased morbidity and mortality. Age, bacteremia, and maximum sodium concentration are independently associated with the development of acute kidney injury in this population.

Dexmedetomidine Use in Critically Ill Children With Acute Respiratory Failure.

OBJECTIVE: Care of critically ill children includes sedation but current therapies are suboptimal. To describe dexmedetomidine use in children supported on mechanical ventilation for acute respiratory failure. DESIGN: Secondary analysis of data from the Randomized Evaluation of Sedation Titration for Respiratory Failure clinical trial. SETTING: Thirty-one PICUs. PATIENTS: Data from 2,449 children; 2 weeks to 17 years old. INTERVENTIONS: Sedation practices were unrestrained in the usual care arm. Patients were categorized as receiving dexmedetomidine as a primary sedative, secondary sedative, periextubation agent, or never prescribed. Dexmedetomidine exposure and sedation and clinical profiles are described. MEASUREMENTS AND MAIN RESULTS: Of 1,224 usual care patients, 596 (49%) received dexmedetomidine. Dexmedetomidine as a primary sedative patients (n = 138; 11%) were less critically ill (Pediatric Risk of Mortality III-12 score median, 6 [interquartile range, 3-11]) and when compared with all other cohorts, experienced more episodic agitation. In the intervention group, time in sedation target improved from 28% to 50% within 1 day of initiating dexmedetomidine as a primary sedative. Dexmedetomidine as a secondary sedative usual care patients (n = 280; 23%) included more children with severe pediatric acute respiratory distress syndrome or organ failure. Dexmedetomidine as a secondary sedative patients experienced more inadequate pain (22% vs 11%) and sedation (31% vs 16%) events. Dexmedetomidine as a periextubation agent patients (n = 178; 15%) were those known to not tolerate an awake, intubated state and experienced a shorter ventilator weaning process (2.1 vs 2.3 d). CONCLUSIONS: Our data support the use of dexmedetomidine as a primary agent in low criticality patients offering the benefit of rapid achievement of targeted sedation levels. Dexmedetomidine as a secondary agent does not appear to add benefit. The use of dexmedetomidine to facilitate extubation in children intolerant of an awake, intubated state may abbreviate ventilator weaning. These data support a broader armamentarium of pediatric critical care sedation.

Association Between Progression and Improvement of Acute Kidney Injury and Mortality in Critically Ill Children.

OBJECTIVE: To determine whether the progression and/or improvement of acute kidney injury in critically ill children is associated with mortality. DESIGN: Retrospective. SETTING: Multidisciplinary, tertiary care, 24-bed PICU. PATIENTS: A TOTAL OF: 8,260 patients who were 1 month to 21 years old with no chronic kidney disease admitted between May 2003 and March 2012. INTERVENTIONS: We analyzed patients based on their acute kidney injury stage as per the Kidney Disease Improving Global Outcomes acute kidney injury serum creatinine staging criteria on ICU admission, peak (highest acute kidney injury stage reached), and trough (lowest acute kidney injury stage after the peak) during their ICU stay. Nonrenal organ dysfunction was measured with a modified Pediatric Logistic Organ Dysfunction score. The primary outcome was 28-day mortality. p values were based on Yates-corrected chi-square test and logistic regression. MEASUREMENTS AND MAIN RESULTS: Of the 8,260 patients, 529 (6.4%) had acute kidney injury on ICU admission and 974 (11.8%) had acute kidney injury during their ICU course. The 28-day mortality was 2.7% for patients with no acute kidney injury and 25.3% for patients with acute kidney injury. Patients in whom acute kidney injury developed or had worsening acute kidney injury from admission to peak and reached acute kidney injury stage 2 or 3 had higher mortality than those who remained at an acute kidney injury stage 1 (17.3-17.8% vs 32.2-37.9%; p ≤ 0.003). Patients whose acute kidney injury resolved after the peak had lower mortality than those who retained the same degree of acute kidney injury (9-13.5% vs 37.3-44%; p ≤ 0.04). Patients with acute kidney injury that resolved still had higher mortality than those who never developed acute kidney injury (11.2% vs 2.7%; p < 0.001). Multivariate regression demonstrated that the association between mortality and acute kidney injury progression was independent of severity of illness at admission and the severity of nonrenal organ dysfunction during the first week of ICU stay (p ≤ 0.01). CONCLUSION: Progression of acute kidney injury per the Kidney Disease Improving Global Outcomes staging criteria is independently associated with increased mortality in the PICU while its improvement is associated with a stepwise decrease in mortality.

Comparison of SpO2 to PaO2 based markers of lung disease severity for children with acute lung injury.

OBJECTIVE: Given pulse oximetry is increasingly substituting for arterial blood gas monitoring, noninvasive surrogate markers for lung disease severity are needed to stratify pediatric risk. We sought to validate prospectively the comparability of SpO2/Fio2 to PaO2/Fio2 and oxygen saturation index to oxygenation index in children. We also sought to derive a noninvasive lung injury score. DESIGN: Prospective, multicentered observational study in six pediatric intensive care units. PATIENTS: One hundred thirty-seven mechanically ventilated children with SpO2 80% to 97% and an indwelling arterial catheter. INTERVENTIONS: Simultaneous blood gas, pulse oximetry, and ventilator settings were collected. Derivation and validation data sets were generated, and linear mixed modeling was used to derive predictive equations. Model performance and fit were evaluated using the validation data set. MEASUREMENTS AND MAIN RESULTS: One thousand one hundred ninety blood gas, SpO2, and ventilator settings from 137 patients were included. Oxygen saturation index had a strong linear association with oxygenation index in both derivation and validation data sets, given by the equation oxygen saturation index = 2.76 1 0.547*oxygenation index (derivation). 1/SpO2/Fio2 had a strong linear association with 1/PaO2/Fio2 in both derivation and validation data sets given by the equation 1/SpO2/Fio2 = 0.00232 1 0.443/PaO2/Fio2 (derivation). SpO2/Fio2 criteria for acute respiratory distress syndrome and acute lung injury were 221 (95% confidence interval 215-226) and 264 (95% confidence interval 259-269). Multivariate models demonstrated that oxygenation index, serum pH, and Paco(2) were associated with oxygen saturation index (p < .05); and 1/PaO2/Fio2, mean airway pressure, serum pH, and Paco2 were associated with 1/SpO2/Fio2 (p < .05). There was strong concordance between the derived noninvasive lung injury score and the original pediatric modification of lung injury score with a mean difference of 20.0361 α0.264 sd. CONCLUSIONS: Lung injury severity markers, which use SpO2, are adequate surrogate markers for those that use PaO2 in children with respiratory failure for SpO2 between 80% and 97%. They should be used in clinical practice to characterize risk, to increase enrollment in clinical trials, and to determine disease prevalence.

Pediatric upper airway obstruction: interobserver variability is the road to perdition.

PURPOSE: The purposes of the study are to determine the interobserver variability in the clinical assessment of pediatric upper airway obstruction (UAO) and to explore how variability in assessment of UAO may contribute to risk factors and incidence of postextubation UAO. MATERIALS: This is a prospective trial in 2 tertiary care pediatric intensive care units. Bedside practitioners performed simultaneous, blinded UAO assessments on 112 children after endotracheal extubation. RESULTS: Agreement among respiratory therapists, pediatric intensive care nurses, and pediatric intensive care physicians was poor for cyanosis (κ = 0.01) and hypoxemia at rest (κ = 0.14) and fair for consciousness (κ = 0.27), air entry (κ = 0.32), hypoxemia with agitation (κ = 0.27), and pulsus paradoxus (κ = 0.23). When looking at "stridor" and "retractions," defined using more than 2 grades of severity from the Westley Croup Score, the interrelater reliability was moderate (κ = 0.43 and κ = 0.47, respectively). This could be improved marginally by dichotomizing the presence or absence of stridor (κ = 0.54) or retractions (κ = 0.53). The overall incidence of UAO after extubation (stridor plus retractions) could range from 7% to 22%, depending on how many providers were required to agree. CONCLUSIONS: Physical findings routinely used for UAO have poor interobserver reliability among bedside providers. This variability may contribute to inconsistent findings regarding incidence, risk factors, and therapies for postextubation UAO.