Administration of Milrinone Following Tetralogy of Fallot Repair Increases Postoperative Volume Administration Without Improving Cardiac Output.

BACKGROUND: Phosphodiesterase inhibitors are known to relieve symptoms in the setting of heart failure, although their effects in restrictive ventricular physiology have been poorly characterized. We explored the association between the use of milrinone and volume administration during the first 72 hours following surgical repair of tetralogy of Fallot (TOF). METHODS: We reviewed all cases of primary surgical repair of TOF with pulmonary stenosis or atresia at Boston Children's Hospital between 2011 and 2020. To adjust for baseline differences between patients who did and did not receive milrinone, we matched patients with similar propensity scores in a 1:1 ratio (use of milrinone versus not). We then compared the need for volume administration during the first 72 hours postoperatively, vital signs, and measures of cardiac output between the matched cohorts. Additionally, in the group of patients receiving milrinone, linear regression modeling was used to explore the relationship between total dose of milrinone and total volume administration. RESULTS: Among 351 included patients, 134 received perioperative milrinone. A total of 212 patients (106 per group) were matched based on anatomic and surgical risks using a propensity score. After propensity matching, compared with nonmilrinone-treated patients, milrinone-treated patients were given postoperative volume more frequently (66% vs 52%; difference 14% [95% confidence interval, CI, 1%-27%]; P = .036). Milrinone-treated patients had a slower recovery of tachycardia during the first 12 hours (difference in slope 0.30 [95% CI, 0.14-0.47] beats per minute [BPM]/h; P < .001), and the intergroup difference peaked at 12 hours postoperatively (8 [95% CI, 5-12] BPM). Milrinone administration was not associated with improved cardiac output, including arteriovenous oxyhemoglobin saturation difference. In propensity-matched patients receiving milrinone, the total volume administered during the first 72 postoperative hours was significantly associated with the cumulative dose of postoperative milrinone ( r = 0.20; 95% CI, 0.01-0.38; P = .036). Based on the slope of the regression line, for every 1000 µg/kg of milrinone (equivalent to ~0.25 µg/kg/min for 72 hours) administered in the first 72 postoperative hours, an estimated 11.0 (95% CI, 0.6-21.4) mL/kg additional volume was administered. CONCLUSIONS: The use of milrinone within the first 72 hours following TOF repair is associated with more frequent administration of volume, a positive association between a higher total dose of postoperative milrinone and the amount of postoperative volume administered, a higher heart rate, and a lower blood pressure, but is not associated with improved cardiac output.

Impact of Dexmedetomidine Infusion on Opioid and Benzodiazepine Doses in Ventilated Pediatric Patients in the Cardiac Intensive Care Unit.

INTRODUCTION: Dexmedetomidine (DEX) is frequently used as an adjunct agent for prolonged sedation in the intensive care unit (ICU), though its effect on concomitant opioids or benzodiazepines infusions is unclear. We explored the impact of DEX on concomitant analgosedation in a cohort of ventilated pediatric patients in a cardiac ICU, with stratification of patients according to duration of ventilation (< 5 versus ≥ 5 days) following DEX initiation. METHODS: We conducted a retrospective analysis on ventilated patients receiving a DEX infusion ≥ 24 h and at least one other sedative/analgesic infusion (January 2011-June 2021). We evaluated trends of daily doses of opioids and benzodiazepines from 24 h before to 72 h following DEX initiation, stratifying patients based on ventilation duration after DEX initiation (< 5 versus ≥ 5 days). RESULTS: After excluding 1146 patients receiving DEX only, 1073 patients were included [median age 234 days (interquartile range 90, 879)]. DEX was associated with an opioid infusion in 99% of patients and a benzodiazepine infusion in 62%. Among patients ventilated for < 5 days (N = 761), opioids increased in the first 24 h following DEX initiation [+ 1.12 mg/kg/day (95% CI 0.96, 1.23), P < 0.001], then decreased [- 0.90 mg/kg/day (95% CI - 0.89, - 0.71), P < 0.001]; benzodiazepines slowly decreased [- 0.20 mg/kg/day (95% CI - 0.21, - 0.19), P < 0.001]. Among patients ventilated for ≥ 5 days (N = 312), opioid administration doubled [+ 2.09 mg/kg/day (95% CI 1.82, 2.36), P < 0.001] in the first 24 h, then diminished minimally [- 0.18 mg/kg/day (95% CI - 0.32, - 0.04), P = 0.015] without returning to baseline; benzodiazepine administration decreased minimally [- 0.03 mg/kg/day (95% CI - 0.05, - 0.01), P = 0.010]. Similar trends were confirmed when adjusting for age, gender, surgical complexity, recent major invasive procedures, duration of mechanical ventilation before DEX initiation, extubation within 72 h following DEX initiation, mean hourly DEX dose, and use of neuromuscular blocking infusion. CONCLUSION: While in patients ventilated < 5 days opioids initially increased and then quickly decreased in the 72 h following DEX initiation, among patients ventilated ≥ 5 days opioids doubled, then decreased only minimally; benzodiazepines decreased minimally in both groups, although more slowly in the long-ventilation cohort. These findings may inform decision-making on timing of DEX initiation in ventilated patients already being treated with opioid or benzodiazepine infusions.

Modeling severe functional impairment or death following ECPR in pediatric cardiac patients: Planning for an interventional trial.

AIM: We aimed to characterize extracorporeal CPR (ECPR) outcomes in our center and to model prediction of severe functional impairment or death at discharge. METHODS: All ECPR events between 2011 and 2019 were reviewed. The primary outcome measure was severe functional impairment or death at discharge (Functional Status Score [FSS] ≥ 16). Organ dysfunction was graded using the Pediatric Logistic Organ Dysfunction Score-2, neuroimaging using the modified Alberta Stroke Program Early Computed Tomography Score. Multivariable logistic regression was used to model FSS ≥ 16 at discharge. RESULTS: Of the 214 patients who underwent ECPR, 182 (median age 148 days, IQR 14-827) had an in-hospital cardiac arrest and congenital heart disease and were included in the analysis. Of the 110 patients who underwent neuroimaging, 52 (47%) had hypoxic-ischemic injury and 45 (41%) had hemorrhage. In-hospital mortality was 52% at discharge. Of these, 87% died from the withdrawal of life-sustaining therapies; severe neurologic injury was a contributing factor in the decision to withdraw life-sustaining therapies in 50%. The median FSS among survivors was 8 (IQR 6-8), and only one survivor had severe functional impairment. At 6 months, mortality was 57%, and the median FSS among survivors was 6 (IQR 6-8, n = 79). Predictive models identified FSS at admission, single ventricle physiology, extracorporeal membrane oxygenation (ECMO) duration, mean PELOD-2, and worst mASPECTS (or DWI-ASPECTS) as independent predictors of FSS ≥ 16 (AUC = 0.931) and at 6 months (AUC = 0.924). CONCLUSION: Mortality and functional impairment following ECPR in children remain high. It is possible to model severe functional impairment or death at discharge with high accuracy using daily post-ECPR data up to 28 days. This represents a prognostically valuable tool and may identify endpoints for future interventional trials.