Author Of 5 Presentations
THE FUTURE OF PAEDIATRIC CRITICAL CARE
SEDATION AND ANALGESIA FOLLOWING THE FDA WARNING
ALTERED MICROCIRCULATORY BLOOD FLOW QUALITY AFTER ELECTIVE CARDIAC SURGERY ON CARDIOPULMONARY BYPASS
Abstract
Background
Monitoring of the sublingual microcirculation (SMC) offers insight into tissue oxygenation. In contrast to findings in adults, it remains unclear whether children undergoing cardiac surgery on cardiopulmonary bypass (CPB) also show SMC alterations and thus altered tissue oxygenation.
Objectives
To assess whether SMC is altered during the first 6h after cardiac surgery.
Methods
We performed a prospective observational study in a tertiary children’s hospital. Children aged 0–17 years undergoing cardiac surgery on CPB were eligible. SMC was monitored before and until 6h after surgery with handheld vital microscopy. Parameters of vessel density and perfusion were assessed for all vessels (diameter <100µm) and capillaries (<20µm). Mixed models were built to assess change over time and identify covariates.
Results
Thirty-eight patients (median age 0.62 years (IQR: 3.06), 16 females, 20 cyanotic heart defects, frequency RACHS-1 categories 1-6: 6, 21, 9, 1, 0 and 1 respectively) were included. All patients survived. Microcirculatory flow index of capillaries (MFI<20µm), i.e. flow quality, decreased after surgery (2.8 (IQR: 0.4) to 2.5 (IQR: 0.6)) and did not improve 6h after surgery. Other SMC parameters were unaltered after surgery and did not change over time. SMC parameters did not differ between cyanotic and acyanotic heart defects. Perfused vessel density of capillaries was higher in neonates or males or if PaO2 increased. MFI<20µm was higher if RACHS-1 category >2, if mean arterial pressure increased or if pH or bleeding decreased.
Conclusion
Blood flow quality of capillaries was decreased during the first hours after cardiac surgery, a sign of otherwise unnoticed altered tissue oxygenation.
THERAPEUTIC DRUG MONITORING IS ESSENTIAL FOR PHENOBARBITAL DOSING IN NEONATES ON EXTRACORPOREAL MEMBRANE OXYGENATION
Abstract
Background
Phenobarbital is a frequently used anticonvulsive drug in patients undergoing extracorporeal membrane oxygenation (ECMO). The use of ECMO is associated with significant changes in drug pharmacokinetics (PK), which may lead to insufficient or toxic effects.
Objectives
The aim of this study was to characterize PK of phenobarbital in neonates on ECMO.
Methods
Therapeutic data monitoring (TDM) data from 11 (6 female, 5 male) neonates (median (IQR), body weight (BW): 3.16 (2.63-4.02) kg; postnatal age (PNA): 8 (4-17) days, gestational age: 38.6 (38-41) weeks) treated with veno-venous or veno-arterial ECMO were available, 5 phenobarbital concentrations were determined before ECMO, 31 during ECMO and 17 concentrations after decannulation. TDM data from a control group included 50 neonates (BW: 3.3 (2.8 to 3.5) kg, PNA: 2 (1-3) days, GA: 39 (38 to 40) weeks). Population PK analysis was performed using NONMEM® version 7.3. Maturation functions based on BW and PNA for clearance (CL) and based on BW for distribution volume (Vd) were obtained from literature (1).
Results
CL values before start of ECMO were comparable to the reference population. There was a 3.5-fold increase in phenobarbital CL during ECMO compared to the reference population, with a trend towards a time-dependent increase. Furthermore, phenobarbital CL reduced 2-fold after decannulation compared to CL during ECMO. Changes in Vd with ECMO could not be identified.
Conclusion
CL is the only parameter driving steady state concentrations for phenobarbital. ECMO leads to high inter-individual variability in CL of phenobarbital, therefore TDM is essential in these patients.