Effect of timing and route of methylprednisolone administration during pediatric cardiac surgical procedures.

BACKGROUND: We compared the antiinflammatory and cardioprotective effects of the two most common regimens of corticosteroid administration in pediatric cardiac surgical procedures: a single dose delivered either at anesthesia induction or by cardiopulmonary bypass (CPB) prime. METHODS: Forty-five children, aged between 1 and 18 months and undergoing ventricular septal or atrioventricular septal defect correction, were randomized in double-blind fashion into three groups. The anesthesia induction group received 30 mg/kg methylprednisolone intravenously after anesthesia induction, and the CPB-prime group received 30 mg/kg methylprednisolone by CPB circuit. The placebo group received saline solution. Plasma concentrations of methylprednisolone, interleukin (IL)-6, IL-8 and IL-10, and troponin were measured at anesthesia induction before the study drug, 30 minutes on CPB, after patients were weaned from CPB, and 6 hours after cessation of CPB. RESULTS: Equally high methylprednisolone concentrations were detected in both methylprednisolone groups, but the measured peak concentration occurred earlier in the induction group. Significantly lower IL-8 concentrations were observed just after patients were weaned from and 6 hours after CPB in the anesthesia induction group compared with the placebo (p = 0.002, p = 0.001) and prime groups (p = 0.003, p = 0.006). Significant reductions of troponin were detected in both methylprednisolone groups compared with placebo (induction, p = 0.001; prime, p = 0.002) 6 hours after patients were weaned from CPB. CONCLUSIONS: Methylprednisolone administration at anesthesia induction was superior in terms of antiinflammatory action. Methylprednisolone administration in CPB-prime only a few minutes before aortic cross-clamping and cardioplegia resulted in mean troponin reductions similar to those of administration at anesthesia induction. Corticosteroids may have direct cardioprotective properties, as reported in experimental studies.

Methylprednisolone in neonatal cardiac surgery: reduced inflammation without improved clinical outcome.

BACKGROUND: Corticosteroids are widely used in pediatric open-heart surgery to reduce systemic inflammatory response and to mediate possible cardioprotective effects. However, the optimal dosing of corticosteroids is unknown and their administration varies considerably between different institutions. METHODS: Forty neonates undergoing open-heart surgery were randomized in a double-blind fashion equally into 2 groups. After the induction of anesthesia, 1 group received 30 mg/kg intravenous methylprednisolone and the other a placebo. Concentrations in plasma of interleukin 6 (IL-6), IL-8, IL-10, free methylprednisolone and total methylprednisolone were obtained for the following: (1) at anesthesia induction before the study drug was administered; (2) 30 minutes on cardiopulmonary bypass; (3) 5 minutes after protamine administration; and (4) 6 hours after weaning from cardiopulmonary bypass. Troponin T was measured at time points T1, T3, T4, and also at 6:00 on the first postoperative morning. Physiological and clinical outcome parameters were also recorded. RESULTS: Intravenous methylprednisolone resulted in high plasma drug concentrations that peaked at T2. Methylprednisolone significantly lowered concentrations of proinflammatory cytokines IL-6 and IL-8 and raised levels of anti-inflammatory IL-10. No significant differences in troponin T levels were detected. Blood glucose levels were significantly higher in the methylprednisolone group, and patients in this group received more often insulin therapy than controls. No significant differences were observed in other clinical or physiological outcome measurements. CONCLUSIONS: Intravenous 30 mg/kg methylprednisolone administered before cardiopulmonary bypass resulted in high effective plasma drug concentrations and a decreased inflammatory response. However, no cardioprotective effect or better clinical outcome was noticed.

Microbial growth inside insulated external walls as an indoor air biocontamination source.

The association between moisture-related microbial growth (mesophilic fungi and bacteria) within insulated exterior walls and microbial concentrations in the indoor air was studied. The studied apartment buildings with precast concrete external walls were situated in a subarctic zone. Actinomycetes in the insulation layer were found to have increased concentrations in the indoor air. The moisture content of the indoor air significantly affected all measurable airborne concentrations.