Diuretic response after neonatal cardiac surgery: a report from the NEPHRON collaborative.

BACKGROUND: Multicenter early diuretic response (DR) analysis of single furosemide dosing following neonatal cardiac surgery is lacking to inform whether early DR predicts adverse clinical outcomes. METHODS: We performed a retrospective cohort study utilizing data from the NEPHRON registry. Random forest machine learning generated receiver operating characteristic-area under the curve (ROC-AUC) and odds ratios for mechanical ventilation (MV) and respiratory support (RS). Prolonged MV and RS were defined using ≥ 90th percentile of observed/expected ratios. Secondary outcomes were prolonged CICU and hospital length of stay (LOS) and kidney failure (stage III acute kidney injury (AKI), peritoneal dialysis, and/or continuous kidney replacement therapy on postoperative day three) assessed using covariate-adjusted ROC-AUC curves. RESULTS: A total of 782 children were included. Cumulative urine output (UOP) metrics were lower in prolonged MV and RS patients, but DR poorly predicted prolonged MV (highest AUC 0.611, OR 0.98, sensitivity 0.67, specificity 0.53, p = 0.006, 95% OR CI 0.96-0.99 for cumulative 6-h UOP) and RS (highest AUC 0.674, OR 0.94, sensitivity 0.75, specificity 0.54, p < 0.001, 95% CI 0.91-0.97 UOP between 3 and 6 h). Secondary outcome results were similar. DR had fair discrimination for kidney failure (AUC 0.703, OR 0.94, sensitivity 0.63, specificity 0.71, 95% OR CI 0.91-0.98, p < 0.001, cumulative 6-h UOP). CONCLUSIONS: Early DR poorly discriminated patients with prolonged MV, RS, and LOS in this cohort, though it may identify severe postoperative AKI phenotype. Future work is warranted to determine if early DR or late postoperative DR later, in combination with other AKI metrics, may identify a higher-risk phenotype.

A Quality Improvement Initiative to Reduce Unnecessary Screening Chest Radiographs in a Pediatric ICU.

BACKGROUND: The Critical Care Societies Collaborative included not ordering diagnostic tests at regular intervals as one of their Choosing Wisely initiatives. A reduction in unnecessary chest radiographs (CXRs) can help reduce exposure to radiation and eliminate health care waste. We aimed to reduce daily screening CXRs in a pediatric ICU (PICU) by 20% from baseline within 4 months of implementation of CXR criteria. METHODS: All intubated patients in the PICU were included in this quality improvement project. Patients with tracheostomies were excluded. We developed criteria delineating which patients were most likely to benefit from a daily screening CXR, and these criteria were discussed for each patient on rounds. Patients on extracorporeal membrane oxygenation, on high-frequency oscillatory ventilation, or on high support on conventional mechanical ventilation were included as needing a daily screening CXR. We tracked the percentage of intubated subjects receiving a screening CXR as an outcome measure. Unplanned extubations and the number of non-screening CXRs per intubated subject were followed as balancing measures. RESULTS: The percentage of intubated subjects receiving a daily screening CXR was reduced from 79% to 31%. There was no increase in frequency of unplanned extubations or number of non-screening CXRs. With an estimated subject charge of roughly $270 and hospital cost of $54 per CXR, this project led to an estimated $300,000 in patient charge savings and $60,000 in hospital cost savings. CONCLUSIONS: Adopting criteria to delineate which patients are most likely to benefit from screening CXRs can lead to a reduction in the percentage of intubated patients receiving screening CXRs without appearing to increase harm.

A survey of current practices in sedation, analgesia, withdrawal, and delirium management in paediatric cardiac ICUs.

OBJECTIVE: To characterise the current approach to sedation, analgesia, iatrogenic withdrawal syndrome and delirium in paediatric cardiac ICUs. DESIGN: A convenience sample survey of practitioners at institutions participating in the Pediatric Cardiac Critical Care Consortium conducted from September to December 2020. SETTING: Paediatric cardiac ICUs. MEASUREMENTS AND MAIN RESULTS: Survey responses were received from 33 of 42 institutions contacted. Screening for pain and agitation occurs commonly and frequently. A minority of responding centres (39%) have a written analgesia management protocol/guideline. A minority (42%) of centres have a written protocol for sedation. Screening for withdrawal occurs commonly, although triggers for withdrawal screening vary. Only 42% of respondents have written protocols for withdrawal management. Screening for delirium occurs "always" in 46% of responding centres, "sometimes" in 36% of centres and "never" 18%. Nine participating centres (27%) have written protocols for delirium management. CONCLUSIONS: Our survey identified that most responding paediatric cardiac ICUs lack a standardised approach to the management of analgesia, sedation, iatrogenic withdrawal, and delirium. Screening for pain and agitation occurs regularly, while screening for withdrawal occurs fairly frequently, and screening for delirium is notably less consistent. Only a minority of centres use written protocols or guidelines for the management of these problems. We believe that this represents an opportunity to significantly improve patient care within the paediatric cardiac ICU.

A Quality Improvement Initiative to Reduce Unneeded Screening Chest Radiographs in a Pediatric Cardiovascular ICU.

BACKGROUND: Adult critical care and radiographical societies have recommended changing practice from routine screening radiographs to on-demand chest radiographs (CXRs) for stable mechanically ventilated adult patients. There are no similar recommendations for patients in the pediatric ICU. Reducing the frequency with which unneeded CXRs are obtained can decrease radiation exposure and reduce waste, a substantial contributor to rising health care costs. We aimed to reduce unneeded daily screening CXRs in a pediatric cardiovascular ICU (CICU) by 20% in 6 months. METHODS: Criteria delineating which subjects in the CICU required daily screening CXRs were created and added to the daily rounding sheet for discussion for each subject. The primary goal of this study was to reduce CXRs in mechanically ventilated subjects as our previous practice had been to order daily CXRs. Respiratory therapists increased the frequency of evaluating and documenting endotracheal tube positioning prior to the initiation of this project. The outcome measure was the percentage subjects who received a daily screening CXR. The ratio of daily screening CXRs to the number of total CXRs ordered and unplanned extubations were followed as balancing measures. RESULTS: The number of subjects who received a daily screening CXR decreased from a baseline of 67% to 44% over the course of this project. There was no change in the ratio of daily screening CXRs to the number of total CXRs ordered or an increase in unplanned extubations. With an estimated cost of $268 per CXR, a reduction of 33% in routine screening CXRs saves an estimated $250,000 annually. CONCLUSIONS: A decrease in daily screening CXRs can be sustained through the development of specific criteria to determine which patients need screening radiographs. This can be achieved without an increase in CXRs obtained at other times throughout the day or an increase in unplanned extubations. This eliminates unneeded health care expenditures, improves resource allocation for radiology technicians, and decreases disruptive interventions for patients.

PICU Pharmacology.

The care of the critically-ill child often includes medications used to optimize organ function, treat infections, and provide comfort. Pediatric pharmacology has some key differences that should be leveraged for safe pharmacologic management.

Analgesia, Sedation, Paralytics, Delirium, and Iatrogenic Withdrawal.

The care of the critically ill child often includes medications used for the relief of pain and anxiety. Children have key differences in pharmacokinetics and pharmacodynamics compared with adults that should always be considered to achieve safe medication use in this population. Pain must be addressed, and sedative use should be minimized when possible. Our understanding of sedation safety is evolving, and studies have shown that minimizing exposure to multiple medications can reduce the burden of delirium and iatrogenic withdrawal.

Fluid Accumulation After Neonatal Congenital Cardiac Operation: Clinical Implications and Outcomes.

BACKGROUND: This study was conducted to determine the association between fluid balance metrics and mortality and other postoperative outcomes after neonatal cardiac operation in a contemporary multicenter cohort. METHODS: This was an observational cohort study across 22 hospitals in neonates (≤30 days) undergoing cardiac operation. We explored overall percentage fluid overload, postoperative day 1 percentage fluid overload, peak percentage fluid overload, and time to first negative daily fluid balance. The primary outcome was in-hospital mortality. Secondary outcomes included postoperative duration of mechanical ventilation and intensive care unit (ICU) and hospital length of stay. Multivariable logistic or negative binomial regression was used to determine independent associations between fluid overload variables and each outcome. RESULTS: The cohort included 2223 patients. In-hospital mortality was 3.9% (n = 87). Overall median peak percentage fluid overload was 4.9% (interquartile range, 0.4%-10.5%). Peak percentage fluid overload and postoperative day 1 percentage fluid overload were not associated with primary or secondary outcomes. Hospital resource utilization increased on each successive day of not achieving a first negative daily fluid balance and was characterized by longer duration of mechanical ventilation (incidence rate ratio, 1.11; 95% CI, 1.08-1.14), ICU length of stay (incidence rate ratio, 1.08; 95% CI, 1.03-1.12), and hospital length of stay (incidence rate ratio, 1.09; 95% CI, 1.05-1.13). CONCLUSIONS: Time to first negative daily fluid balance, but not percentage fluid overload, is associated with improved postoperative outcomes in neonates after cardiac operation. Specific treatments to achieve an early negative fluid balance may decrease postoperative care durations.

Reducing Unnecessary Nitric Oxide Use: A Hospital-Wide, Respiratory Therapist-Driven Quality Improvement Project.

BACKGROUND: We sought to evaluate the institutional use of inhaled nitric oxide (INO) and to create a pathway to reduce waste using the Institute for Healthcare Improvement's model for improvement. Our aim was to reduce the use of INO by 20% within 8 months. METHODS: This was a prospective, respiratory therapist-driven, quality improvement project. We implemented a hospital-wide INO utilization protocol that was developed by neonatology, pediatric critical care, cardiac critical care, and respiratory therapy. INO use and respiratory therapist input for protocol failures were derived from the electronic medical record and were used to generate improvement opportunities. Monthly total hospital use of INO (in hours) was used as the primary outcome measure. Median hourly use per subject (evaluated in groups of 7 subjects) was used as a secondary outcome measure. New sildenafil dosing was tabulated for pre- and post-INO weaning protocol intervention as a balancing measure. Subjects included all patients in the hospital who were given INO therapy during the specified timeframe. RESULTS: Hospital-wide total hours were reduced from 1,515 h/month to 930 h/month. This hospital-wide reduction of 39% equates to a cost-avoidance of approximately $912,000 per year based on 2018 costs of INO of $130 per hour. Median hours of INO per subject decreased from 88 h to 50 h. Sildenafil was started in 18 of 98 subjects (18%) in the pre-intervention period and in 12 of 109 subjects (11%) in the post-intervention period (P = .27). CONCLUSIONS: A hospital-wide, multi-professional initiative led to a reduction in unnecessary INO use, resulting in decreased subject exposure and associated cost avoidance.

Analysis of Patient Characteristics and Risk Factors for Thrombosis After Surgery for Congenital Heart Disease.

OBJECTIVES: Thrombosis is a cause of morbidity in 4-15% of children who undergo pediatric cardiac surgery. Data on how to prevent this complication are sorely needed. We aimed to identify risk factors for thrombosis following pediatric cardiac surgery and determine if use of low molecular weight heparin prophylaxis is associated with a reduction in thrombosis risk. DESIGN: Retrospective cohort study. SETTING: Tertiary pediatric cardiovascular ICU. PATIENTS: Patients who underwent cardiac surgery between June 2014 and December 2015. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Data from patients with venous or arterial thrombosis confirmed by radiologic studies were matched two-to-one to controls based on age, Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery mortality category, and gender. Thrombosis was detected in 33 patients (6.2%): 25 patients (76%) had venous thromboses, five patients (15%) had arterial thromboses, and three patients (9%) had both. Median time to thrombosis detection was 13 days (25-75%; 7-31 d). On multivariate analysis, which included adjustment for postoperative disease severity, fresh frozen plasma exposure was independently associated with thrombosis (odds ratio, 3.7; 95% CI, 1.4-9.4). Twenty-eight patients (85%) had central venous catheter-related thromboses. Low molecular weight heparin prophylaxis use in this subset of patients was not statistically different from controls (50% vs 45%, respectively; p = 0.47). On multivariable analysis, fresh frozen plasma exposure was also independently associated with central venous catheter-related thrombosis (odds ratio, 3.6; 95% CI, 1.2-10.6). CONCLUSIONS: The occurrence of thrombosis after pediatric cardiac surgery at our institution was 6.2%, similar to what has been reported in other studies, despite frequent use of low molecular weight heparin. Further study is needed to determine the role of low molecular weight heparin for thromboprophylaxis and the relationship between fresh frozen plasma and thrombosis risk in children who undergo cardiac surgery.

Utility of routine methemoglobin laboratory assays in critically ill pediatric subjects receiving inhaled nitric oxide.

PURPOSE: Inhaled nitric oxide (iNO) has been associated with safety risks including reports of methemoglobinemia. While standard of care recommends routine monitoring of methemoglobin in subjects on iNO therapy, the utility of this practice remains unknown. MATERIALS AND METHODS: This retrospective chart review aimed to determine the frequency of methemoglobinemia in pediatric patients receiving iNO. Included subjects were under 18 years of age receiving iNO therapy with at least one methemoglobin concentration measured from 10/18/2014 to 11/18/2016. RESULTS: In total, 1809 methemoglobin concentrations were collected in 247 subjects during the study period. Median age was 0.33 (0.04-0.83) years. The mean methemoglobin concentration was 1.33% (±0.42) while receiving a mean iNO dose of 11.71 ppm (±7.97). Twenty-nine subjects had a total of 131 methemoglobin concentrations analyzed while receiving iNO doses above 20 ppm which were similar to the entire cohort at 1.33% (±0.42); (p = .95). CONCLUSIONS: Pediatric patients receiving iNO at doses below 40 ppm have minimal risk of developing clinically significant methemoglobinemia. Routine, ongoing monitoring of metHb levels in all pediatric subjects receiving iNO therapy at doses <40 ppm without the presence of risk factors predisposing the subject to increased risk of methemoglobinemia is unnecessary and should be avoided.

Portable Device for Measuring Breath Acetone Based on Sample Preconcentration and Cavity Enhanced Spectroscopy.

A portable and compact device is demonstrated for measuring acetone in breath samples. The device features a 7 cm long high finesse optical cavity as an optical sensor that is coupled to a miniature adsorption preconcentrator containing 0.5 g of polymer material. Acetone is trapped out of breath and released into the optical cavity where it is probed by a near-infrared diode laser operating at ∼1670 nm. With an optical cavity mirror reflectivity of 99.994%, a limit of detection of 159 ppbv (1σ) is demonstrated on samples from breath bags. Initial results on direct breath sampling are presented with a precision of 100 ppbv. The method is validated with measurements made using an ion-molecule reaction mass spectrometer. Data are presented on elevated breath acetone from two individuals following an overnight fast and exercise, and from a third individual during several days of routine behavior.

High Frequency Jet Ventilation in Respiratory Failure Secondary to Respiratory Syncytial Virus Infection: A Case Series.

OBJECTIVE: To describe the utility of high frequency jet ventilation (HFJV) as a rescue therapy in patients with respiratory failure secondary to respiratory syncytial virus (RSV) that was refractory to conventional mechanical ventilation (CMV). DESIGN: Descriptive study by retrospective review. SETTING: Pediatric intensive care unit at a tertiary care children's hospital. PATIENTS: Infants on mechanical ventilation for respiratory failure due to RSV. INTERVENTIONS: Use of HFJV. MAIN RESULTS: Eleven patients were placed on HFJV. There was sustained improvement in ventilation on HFJV with a mean decrease in PCO2 of 9 mmHg at 24 h and 11 mmHg at 72 h. There were no significant changes in oxygenation by oxygenation index. No patients required extracorporeal support or suffered pneumothorax, pneumomediastinum, or subcutaneous emphysema. Ten out of 11 (91%) patients survived to discharge from the hospital. CONCLUSION: High frequency jet ventilation may represent an alternative therapy for RSV-induced respiratory failure that is refractory to CMV.

Cumulative corticosteroid exposure and infection risk after complex pediatric cardiac surgery.

BACKGROUND: Children undergoing cardiac surgery may receive corticosteroids preoperatively to temper cardiopulmonary bypass-related inflammation, postoperatively for hemodynamic instability, and periextubation to reduce airway edema. Recent data have associated preoperative corticosteroids with infection. We aimed to determine if there is a relationship between cumulative corticosteroid exposure and infection. METHODS: A retrospective review of children who underwent cardiac surgery at our institution from January 2009 to July 2010 was performed. To limit study heterogeneity, patients who were 5 years or younger with basic Aristotle score of 7 or higher and intensive care unit stay of 7 days or more were included. Infections during the first 30 postoperative days were recorded, defined as clinically relevant positive blood, urine, respiratory, or wound cultures, or culture-negative sepsis treated with 7 or more days of antimicrobial therapy. Multivariate logistic regression analysis was performed to determine independent risk factors for infection. RESULTS: Seventy-six patients were reviewed. All patients received intraoperative methylprednisolone, 48% received postoperative hydrocortisone, and 86% received periextubation dexamethasone. Twenty-six patients (36%) had 58 infections. On univariate analysis, patients with infection had greater median comprehensive Aristotle score (14.5 [intraquartile range (IQR): 12.5 to 16] versus 11.5 [IQR: 10 to 13.1], p = 0.001), maximum vasoactive inotrope score (29 [IQR: 24 to 40] versus 24 [IQR: 17 to 31], p = 0.031, days endotracheally intubated (12 [IQR: 7 to 30] versus 5 [IQR: 4 to 6.5], p < 0.001), and days of corticosteroid exposure (7 [IQR: 5 to 12] versus 4 [IQR: 2 to 5), p < 0.001). Also, patients with infections more often underwent delayed sternal closure (p = 0.008). On multivariate analysis, days endotracheally intubated (p = 0.023) and days of corticosteroid exposure (p = 0.015) remained significant. CONCLUSIONS: For children undergoing complex cardiac surgery, greater cumulative duration of corticosteroid exposure is independently associated with postoperative infection.

Copeptin as a marker of relative arginine vasopressin deficiency after pediatric cardiac surgery.

PURPOSE: Relative arginine vasopressin (AVP) deficiency after pediatric cardiac surgery has recently been described. Copeptin, a more stable and easily measured product of pro-AVP processing, may be a means of identifying these patients. We aimed to determine if copeptin was correlated with AVP in these children and whether it can be a surrogate marker of relative AVP deficiency. METHODS: Patients <6 years of age with basic Aristotle scores ≥7 requiring surgery with cardiopulmonary bypass were prospectively enrolled. Plasma AVP and copeptin concentrations were measured pre-cardiopulmonary bypass and 4 and 24 h post-cardiopulmonary bypass. Relative AVP deficiency was defined a priori based on our previous work as AVP <9.2 pg/ml at 4 h post-cardiopulmonary bypass. RESULTS: Of 41 children enrolled, relative AVP deficiency was present in 13 (32 %). AVP and copeptin concentrations were significantly lower in these 13 children at 4 h post-cardiopulmonary bypass as compared to the other 28 patients. A significant positive association between plasma AVP and copeptin concentrations over time was determined. Based on log-transformed analyses, a 1 % increase in plasma AVP led to a 0.19 % increase in copeptin. Further, copeptin <1.12 ng/ml at 4 h post-cardiopulmonary bypass had a sensitivity of 92 % and a negative predictive value of 95 % for relative AVP deficiency. CONCLUSIONS: Plasma AVP and copeptin are positively associated in children undergoing cardiac surgery. Copeptin may represent a useful means of identifying relative AVP deficiency in these patients.

Early administration of intratracheal surfactant (calfactant) after hydrocarbon aspiration.

Hydrocarbon ingestions account for a substantial number of accidental poisonings; when aspirated, it can lead to severe pneumonitis. Treatment for severe pneumonitis is generally supportive, and outcomes are frequently poor. We report here the case of a 19-month-old girl who was treated successfully with early administration of exogenous surfactant for acute respiratory distress syndrome secondary to aspiration of lamp oil. Approximately 7 hours after aspiration, she required mechanical ventilation and had an oxygenation index (OI) of 13.2. Approximately 10 hours after ingestion, exogenous surfactant (calfactant) was instilled intratracheally, after which her OI improved markedly to 4.3. She received a second dose ∼19 hours after ingestion, after which her OI remained at <5 and she was progressively weaned from mechanical ventilation. She was extubated 64 hours after the ingestion with no residual lung disease. This case illustrates the importance of considering exogenous surfactant therapy early in the course of acute respiratory failure secondary to hydrocarbon aspiration. Because of the putative mechanisms of lung injury involved in hydrocarbon aspiration, surfactant-replacement therapy is a reasonable therapeutic intervention based on pathophysiologic rationale.

Ethanol lock therapy for catheter-associated blood stream infections in a pediatric intensive care unit.

OBJECTIVE: Ethanol locks are being used to prevent and eradicate central venous catheter infections. This study describes the efficacy of ethanol locks in clearing central venous catheter infections in a pediatric intensive care unit. DESIGN: Retrospective chart review. SETTING: Pediatric intensive care unit in a tertiary care children's hospital. PATIENTS: All patients who received ethanol lock therapy for the treatment of catheter-associated bloodstream infections from January 2008 through December 2009. INTERVENTIONS: Ethanol locks of central venous catheters. MEASUREMENTS AND MAIN RESULTS: The study period encompassed 26 catheter-associated bloodstream infections that were treated with ethanol lock therapy. Each catheter-associated bloodstream infection was defined by criteria set forth by the Centers for Disease Control/National Healthcare Safety Network 2008. Patients ranged in age from 77 days to 20 yrs. Of the 26 central venous catheters with associated bloodstream infections, 24 (92%) were sterilized as evidenced by negative repeat blood cultures obtained within 48 hrs of the initiation of the ethanol lock. Thirteen of the 26 treatment ethanol locks were single doses. The dwell times ranged between 4 and 48 hrs with a mean dwell time of 17 hrs. Twenty of the 26 catheters (77%) continued to be used, while six, which included the two treatment failures, were removed. CONCLUSIONS: Ethanol locks using 70% ethanol solution with dwell times as short as 4-6 hrs in conjunction with standard antibiotic therapy have 92% effective clearance of catheter-associated bloodstream infection and a 77% catheter salvage rate in our pediatric intensive care unit. The use of 70% ethanol locks appears to be well tolerated and represents a relatively inexpensive pharmacologic intervention that, along with systemic antibiotics, can help treat catheter-associated bloodstream infections and salvage central venous catheters.

Infantile iron poisoning: challenges in diagnosis and management.

OBJECTIVE: To describe the clinical course and treatment of an infant with iron poisoning. DESIGN: Case report. SETTING: Pediatric intensive care unit in a tertiary care children's hospital. PATIENT, INTERVENTION, AND RESULTS: A 7-week-old, ex-28-week premature infant, was accidentally poisoned with ferrous sulfate. She recovered completely from metabolic acidosis and shock after treatment with inotropes and chelation with deferoxamine, but her management was complicated by challenges of physiologic immaturity of developing organs. This is the youngest infant reported, to date, with iron poisoning resulting in metabolic acidosis and shock. CONCLUSIONS: This case illustrates the importance of including toxic exposure in the differential diagnosis of neonatal shock of unknown etiology. Because of physiologic immaturity, iron poisoning in young infants poses special diagnostic and therapeutic challenges.