Cardiovascular catecholamine receptors in children: their significance in cardiac disease

Towards integrative physiological monitoring of the critically ill: from cardiovascular to microcirculatory and cellular function monitoring at the bedside

Current hemodynamic monitoring of critically ill patients is mainly focused on monitoring of pressure-derived hemodynamic variables related to systemic circulation. Increasingly, oxygen transport pathways and indicators of the presence of tissue dysoxia are now being considered. In addition to the microcirculatory parameters related to oxygen transport to the tissues, it is becoming increasingly clear that it is also important to gather information regarding the functional activity of cellular and even subcellular structures to gain an integrative evaluation of the severity of disease and the response to therapy. Crucial to these developments is the need to provide continuous measurements of the physiological and pathophysiological state of the patient, in contrast to the intermittent sampling of biomarkers. As technological research and clinical investigations into the monitoring of critically ill patients have progressed, an increasing amount of information is being made available to the clinician at the bedside. This complexity of information requires integration of the variables being monitored, which requires mathematical models based on physiology to reduce the complexity of the information and provide the clinician with a road map to guide therapy and assess the course of recovery. In this paper, we review the state of the art of these developments and speculate on the future, in which we predict a physiological monitoring environment that is able to integrate systemic hemodynamic and oxygen-derived variables with variables that assess the peripheral circulation and microcirculation, extending this real-time monitoring to the functional activity of cells and their constituents. Such a monitoring environment will ideally relate these variables to the functional state of various organ systems because organ function represents the true endpoint for therapeutic support of the critically ill patient.

Levosimendan infusion in newborns after corrective surgery for congenital heart disease: randomized controlled trial

PURPOSE

To evaluate the safety and efficacy of levosimendan in neonates with congenital heart disease undergoing cardiac surgery with cardiopulmonary bypass (CPB).

METHODS

Neonates undergoing risk-adjusted classification for congenital heart surgery (RACHS) 3 and 4 procedures were randomized to receive either a 72 h continuous infusion of 0.1 μg/kg/min levosimendan or standard post-CPB inotrope infusion.

RESULTS

Sixty-three patients (32 cases and 31 controls) were recruited. There were no differences between groups regarding demographic and baseline clinical data. No side effects were observed. There were no significant differences in mortality (1 vs. 3 patients, p = 0.35), length of mechanical ventilation (5.9 ± 5 vs. 6.9 ± 8 days, p = 0.54), and pediatric cardiac intensive care unit (PCICU) stay (11 ± 8 vs. 14 ± 14 days, p = 0.26). Low cardiac output syndrome occurred in 37 % of levosimendan patients and in 61 % of controls (p = 0.059, OR 0.38, 95 % CI 0.14-1.0). Postoperative heart rate, with a significant difference at 6 (p = 0.008), 12 (p = 0.037), and 24 h (p = 0.046), and lactate levels, with a significant difference at PCICU admission (p = 0.015) and after 6 h (p = 0.048), were lower in the levosimendan group. Inotropic score was significantly lower in the levosimendan group at PCICU admission, after 6 h and after 12 h, (p < 0.0001). According to multivariate analysis, a lower lactate level 6 h after PCICU admission was independently associated with levosimendan administration after correction for CPB time and the need for deep hypothermic circulatory arrest.

CONCLUSIONS

Levosimendan infused in neonates undergoing cardiac surgery was well tolerated with a potential benefit of levosimendan on postoperative hemodynamic and metabolic parameters of RACHS 3-4 neonates.