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Objectives: Ventricular-arterial coupling represents the interaction between the left ventricle and the arterial system. Ventricular-arterial coupling is measured as the ratio between arterial elastance and ventricular end-systolic elastance. Scant information is available in critically ill children about these variables. The aim of this study was to prospectively assess ventricular-arterial coupling after pediatric cardiac surgery and evaluate its association with other commonly recorded hemodynamic parameters. Design: Single-center retrospective observational study. Setting: Pediatric cardiac surgery operating room. Patients: Children undergoing corrective cardiac surgery. Interventions: Hemodynamic monitoring with transesophageal echocardiography. Measurements and Main Results: Twenty-seven patients with biventricular congenital heart disease, who underwent elective cardiac surgery with cardiopulmonary bypass, were enrolled before operating room discharge. Chen single-beat modified method was applied to calculate ventricular-arterial coupling. The median arterial elastance and end-systolic elastance values were 5.9 mm Hg/mL (2.2–9.3 mm Hg/mL) and 4.3 mm Hg/mL (1.9–8.3 mm Hg/mL), respectively. The median ventricular- arterial coupling was 1.2 (1.1–1.6). End-systolic elastance differences between patients with a ventricular-arterial coupling below (low ventricular-arterial coupling) and above (high ventricular-arterial coupling) the median value were –5.2 (95% CI, –6.28 to –0.7; p = 0.008). Differently, arterial elastance differences were –2.1 (95% CI, –5.7 to 1.6; p = 0.19). Ventricular-arterial coupling showed a significant association with pre-ejection time (r, 0.44; p = 0.02), total ejection time (r, –0.41; p = 0.003), cardiac cycle efficiency (r, –0.46; p = 0.02), maximal delta pressure over delta time (r, –0.44; p = 0.02), ejection fraction (r, –0.57; p = 0.01), and systemic vascular resistances indexed (0.56; p = 0.003). After adjustment, total ejection time (p = 0.001), pre-ejection time (p = 0.02), and ejection fraction (p = 0.001) remained independently associated with ventricular-arterial coupling. Conclusions: Median ventricular-arterial coupling values in children after cardiac surgery appear high (above 1). Uncoupling was particularly evident in high ventricular-arterial coupling patients who showed the lowest end-systolic elastance values (but not significantly different arterial elastance values) compared with low ventricular-arterial coupling. Ventricular-arterial coupling appears to be inversely proportional to pre-ejection time, total ejection time, and ejection fraction.

OBJECTIVES The use of levosimendan for paediatric patients with low cardiac output after congenital heart surgery has been recently described. We sought to evaluate ventriculo-arterial coupling (VAC) and other ventricular energetic parameters before and after 72 h from levosimendan start in infants with single-ventricle physiology and cardiac failure after palliation with Norwood or hybrid procedures. METHODS In this single-centre retrospective study, 9 consecutive patients affected by hypoplastic left heart syndrome-like anatomy were retrospectively analysed. Systolic elastance, diastolic elastance, arterial elastance, VAC and cardiac mechanical efficiency were calculated by measuring, through 2-dimensional echocardiography, end-systolic volume and end-diastolic volume and by recording mean arterial pressure and central venous pressure. RESULTS The median (range) weight and age were 2.8 (2.3–6) kg and 16.5 (6–116) days, respectively. After 72 h from levosimendan start, end-systolic volume significantly decreased (−1 ml, −3.2 to −0.1, P = 0.007), whereas mean arterial pressure and end-diastolic volume remained stable. Heart rate showed a significant decrease (−28 beats/min, −41 to 22, P = 0.008). Systolic elastance (2.9 mmHg/ml, 0.4–5.4, P = 0.008), arterial elastance (−5.9, −24 to −0.5, P = 0.038), VAC (−0.86, −1.5 to −0.16, P = 0.009) and cardiac mechanical efficiency (0.18, 0.03–0.22, P = 0.008) differences also showed significant modifications. CONCLUSIONS In a small case series of patients with single-ventricle physiology, levosimendan showed to improve contractility and optimize VAC, with a reduction of heart rate. Monitoring of VAC and ventricular energetics can be an interesting aspect to improve the management of heart failure in infants with univentricular anatomy.

Veno-arterial CO2 difference has been considered as a marker of low cardiac output. This study aimed to evaluate the correlation between veno-arterial CO2 difference and cardiac index estimated by MostCareTM in children after cardiac surgery and its association with other indirect perfusion parameters and the complex clinical course (vasoactive inotropic score above 15 or length of stay above 5 days). Data from 40 patients and 127 arterial and venous CO2 measurements for gap calculation taken 0–5 days postoperatively were available. The median (range) veno-arterial CO2 difference value was 9 (1–25 mmHg). The correlation between veno-arterial CO2 difference and cardiac index was not significant (r: −0.16, p = 0.08). However, there was a significant correlation between veno-arterial CO2 difference and vasoactive inotropic score (r: 0.21, p = 0.02), systolic arterial pressure (r: −0.43, p = 0.0001), dP/dtMAX (r: 0.26, p = 0.004), and arterio-venous O2 difference (r: 0.63, p = 0.0001). Systolic arterial pressure (OR 0.95, 95% CI 0.90–0.99), dP/dtMAX (OR 0.00, 95% CI 0.00–0.06), lactates (OR 1.87, 95% CI 1.21–3.31), and veno-arterial CO2 difference (OR 1.13, 95% CI 1.01–1.35) showed a significant univariate association with the complex clinical course. In conclusion, veno-arterial CO2 difference did not correlate with cardiac index estimated by MostCareTM in our cohort of post-cardiosurgical children, but it identified patients with the complex clinical course, especially when combined with other direct and indirect variables of perfusion.

Introduction: Few data are available regarding intraoperative plasma concentrations of vancomycin administered as prophylaxis in pediatric cardiac surgery. The aims of this study were to investigate during pediatric cardiac surgery with cardiopulmonary bypass(CPB) the attainment of the area-under-the-curve of the vancomycin serum concentrations versus time over surgery to minimum inhibitory concentration ratio(AUCintra/MIC) of 400 (mg × h)/l and/or a target concentration of 15–20 mg/l. Methods: In a prospective study, 40 patients divided into four subgroups (neonates, infants, children <10 years-old, ⩾10 years-old) undergoing cardiac surgery with cardiopulmonary bypass (CPB) were enrolled. A slow vancomycin bolus of 20 mg/kg, up to a maximum dose of 1000 mg was administered before skin incision and a further dose of 10 mg/kg (up to 500 mg) at CPB start. Vancomycin samples were collected intraoperatively at four time points. Results: The median (interquartile range) age was 241.5 days (47–3898) and the median weight was 7.1 kg (3.1–37). The median AUCintra/MIC was 254.73 (165.89–508.06). In 11 patients the AUCintra/MIC target was not reached. Neonates displayed the lowest AUCintra/MIC values, and these were significantly lower than those of children ⩾10 years old (p = 0.02). Vancomycin concentrations were above the maximal target of 20 mg/l in 82.5% and 80% of patients at surgery and CPB start, respectively. At CPB and surgery end, 42.5% of patients showed vancomycin concentrations above 20 mg/l and 42.5% below 15 mg/l. Patients⩾10 years old showed the highest peak values whereas neonates were those with the lowest troughs. AUCintra/MIC correlated with age(r:0.36, p = 0.02), weight(r:0.35, p = 0.03), intraoperative protein value(r:0.40, p = 0.01), CPB priming volume/kg(r:−0.33, p = 0.04), CPB duration(r:0.36, p = 0.02) and vancomycin troughs(r:0.35, p = 0.04). Conclusions: An AUCintra/MIC ⩾400 target was not reached in one-quarter of children undergoing heart surgery. Vancomycin peaked before the start of surgery and neonates were those with the lowest troughs. Vancomycin concentrations are affected by CPB hemodilution and by patients’ age and weight.