The effect of milrinone on hemodynamic and gas exchange parameters in children

Factors associated with renal oxygen extraction in mechanically ventilated children after the Norwood operation: insights from high fidelity haemodynamic data

BACKGROUND

Maintaining the adequacy of systemic oxygen delivery is of utmost importance, particularly in critically ill children. Renal oxygen extraction can be utilised as metric of the balance between systemic oxygen delivery and oxygen consumption. The primary aim of this study was to determine what clinical factors are associated with renal oxygen extraction in children after Norwood procedure.

METHODS

Mechanically ventilated children who underwent Norwood procedure from 1 September, 2022 to 1 March, 2023 were identified as these patients had data collected and stored with high fidelity by the T3 software. Data regarding haemodynamic values, fluid balance, and airway pressure were collected and analysed using Bayesian regression to determine the association of the individual metrics with renal oxygen extraction.

RESULTS

A total of 27,270 datapoints were included in the final analyses. The resulting top two models explained had nearly 80% probability of being true and explained over 90% of the variance in renal oxygen extraction. The coefficients for each variable retained in the best were -1.70 for milrinone, -19.05 for epinephrine, 0.129 for mean airway pressure, -0.063 for mean arterial pressure, 0.111 for central venous pressure, 0.093 for arterial saturation, 0.006 for heart rate, -0.025 for respiratory rate, 0.366 for systemic vascular resistance, and -0.032 for systemic blood flow.

CONCLUSION

Increased milrinone, epinephrine, mean arterial pressure, and systemic blood flow were associated with decreased (improved) renal oxygen extraction, while increased mean airway pressure, central venous pressure, arterial saturation, and systemic vascular resistance were associated with increased (worsened) renal oxygen extraction.

Milrinone for the treatment of heart failure caused by severe Pneumonia in children with congenital heart disease: a meta-analysis

BACKGROUND

Children with congenital heart disease (CHD) are easily complicated by severe pneumonia and heart failure. We aimed to conduct a meta-analysis to evaluate the effects and safety of milrinone for the treatment of heart failure caused by severe pneumonia in children with CHD to provide evidence for the clinical CHD treatment.

METHODS

Two authors searched MEDLINE, PubMed, Embase, Science Direct, Cochrane Central Register of Controlled Trials, the Cochrane Library, Wanfang database, Chinese Biomedical Literature Database, China National Knowledge Infrastructure (CNKI) for randomized controlled trials (RCTs) about the application of milrinone in the treatment of heart failure caused by severe pneumonia in children with CHD in children up to December 10, 2022. Two evaluators independently selected the literature, extracted data and evaluated the methodological quality, meta-analysis was carried out with RevMan 5.3 software.

RESULTS

Eight RCTs involving 680 CHD children complicated by severe pneumonia and heart failure were included in this meta-analysis. Meta-analysis indicated that total effective rate of the milrinone group was higher than that of control group (RR = 1.25, 95%CI: 1.17 ~ 1.34, P < 0.001), the time to stable heart rate of the milrinone group was less than that of control group (RR=-0.88, 95%CI: -1.09~ -0.67, P < 0.001). The time to stable respiration of the milrinone group was less than that of control group (RR=-0.98, 95%CI: -1.17~ -0.78, P < 0.001). The LVEF of the milrinone group was higher than that of control group (RR = 6.46, 95%CI: 5.30 ~ 7.62, P < 0.001). There was no significant difference in the incidence of adverse reactions between the milrinone group and control group (RR = 0.85, 95%CI: 0.47 ~ 1.56, P = 0.061). Funnel plots and Egger regression test results indicated that there were no statistical publication bias amongst the synthesized outcomes (all P > 0.05).

CONCLUSIONS

Milrinone is beneficial to improve clinical symptoms and cardiac function and increase the therapeutic effect and safety in children with CHD complicated by severe pneumonia and heart failure. However, more RCTs with large samples and rigorous design are needed to verify this finding.

Milrinone for treatment of elevated lactate in the pre-operative newborn with hypoplastic left heart syndrome

BACKGROUND

There is a paucity of information reported regarding the use of milrinone in patients with hypoplastic left heart syndrome prior to the Norwood procedure. At our institution, milrinone is initiated in the pre-operative setting when over-circulation and elevated serum lactate levels develop. We aimed to review the responses associated with the administration of milrinone in the pre-operative hypoplastic left heart syndrome patient. Second, we compared patients who received high- versus low-dose milrinone prior to Norwood procedure.

METHODS

Single-centre retrospective study of patients diagnosed with hypoplastic left heart syndrome between January 2000 and December 2019 who underwent Norwood procedure. Patient characteristics and outcomes were compared.

RESULTS

During the study period, 375 patients were identified; 79 (21%) received milrinone prior to the Norwood procedure with median lactate 2.55 mmol/l, and SpO2 93%. Patients who received milrinone were older at the time of Norwood procedure (6 vs. 5 days) and were more likely to be intubated and sedated. In a subset analysis stratifying patients to low- versus high-dose milrinone, median lactate decreased from time of initiation (2.39 vs 2.75 to 1.6 vs 1.8 mmol/l) at 12 hours post-initiation, respectively. Repeated measures analysis showed a significant decrease in lactate levels by 4 hours following initiation of milrinone, that persisted over time, with no significant difference in mean arterial pressure.

CONCLUSIONS

The use of milrinone in the pre-operative over-circulated hypoplastic left heart syndrome patient is well tolerated, is associated with decreased lactate levels, and was not associated with significant hypotension or worsening of excess pulmonary blood flow.

Pulmonary hypertensive crisis in children with pulmonary arterial hypertension undergoing cardiac catheterization

Pediatric patients with pulmonary arterial hypertension (PAH) are considered to be at risk for pulmonary hypertensive crisis (PHC) or even death during right heart catheterization (RHC). This retrospective study was designed to identify the risks and clinical characteristics associated with PHC in pediatric PAH patients. We included 163 consecutive procedures from 147 pediatric patients diagnosed with PAH who underwent diagnostic RHC in Beijing Anzhen Hospital between January 2007 and December 2020. The average patient age was 9.0 ± 4.7 years and 84 (51.5%) were females. Before RHC, over 20% of patients were in New York Heart Association (NYHA) class III-IV. Sedation or general intravenous anesthesia was used in 103 procedures (63.2%), with spontaneous breathing in 93.2%. PHC occurred in 19 patients (11.7%), 5 (3.1%) required cardiac compression, and 1 died (0.6%). Compared to patients without PHC, those who experienced PHC were more likely to be in NYHA class III-IV (p = 0.012) before RHC, require sedation (p = 0.011), had echocardiographic indices of higher peak tricuspid regurgitation velocity (p = 0.018), and right ventricle (RV) to left ventricle (LV) ratio (p < 0.001). Multivariate logistic regression for PHC identified the need for sedation and a higher RV/LV ratio as independent predictors. In conclusion, the risk of RHC remains significant in children with PAH, particularly in those with severe RV dilation who require sedation during cardiac catheterization. Comprehensive evaluation, close monitoring, and appropriate treatment before and during the procedure are essential for reducing mortality.

Effects of Vasopressin Infusion After Pediatric Cardiac Surgery: A Meta-analysis

Vasopressin has been used to augment blood pressure; however, cardiovascular effects after cardiac surgery have not been well established. The primary objective of this study was to survey the current literature and quantify the pooled effect of vasopressin on hemodynamic parameters in children after pediatric cardiac surgery. A systematic review was conducted to identify studies characterizing the hemodynamic effects of vasopressin after pediatric cardiac surgery. Studies were assessed and those of satisfactory quality with pre- and post-vasopressin hemodynamics for each patient were included in the final analyses. 6 studies with 160 patients were included for endpoints during the first 2 h of infusions. Patients who received vasopressin infusion had greater mean, systolic, and diastolic blood pressures and lower heart rates at 2 h after initiation. 8 studies with 338 patients were included for the effects at 24 h. Patients who received vasopressin infusion had lower central venous pressures and decreased lactate concentrations 24 h after initiation. A subset analysis for children with functionally univentricular hearts found significant decrease in inotrope score and central venous pressure. A subset analysis for neonates found significant decrease in inotrope score and fluid balance. Vasopressin leads to decrease in heart rate and increase in blood pressure in the first 2 h of initiation. Later effects include decrease in inotrope score, central venous pressure, fluid balance, and in lactate within the first 24 h. Findings vary in neonates and in those with functionally univentricular hearts although beneficial effects are noted in both.