The effect of dexmedetomidine on renal function after surgery: A systematic review and meta-analysis.

WHAT IS KNOWN AND OBJECTIVE: Acute kidney injury (AKI) is a complication following surgery and has been associated with worsened patient outcomes. Providers have used agents that may confer a degree of renal protection in the perioperative stage. Such is the case of dexmedetomidine, a selective alpha-2 adrenergic agonist used in the intensive care unit (ICU) as a sedative agent. The primary objective of this meta-analysis was to characterize the use of dexmedetomidine and to evaluate its impact on renal markers and outcomes in patients after surgery. METHODS: A systematic review of manuscripts was performed to identify patients who received dexmedetomidine after surgery by searching the PubMed, Embase, and Cochrane databases. The following parameters were captured: blood urea nitrogen (BUN), serum creatinine, creatinine clearance, neutrophil gelatinase-associated lipoprotein (NGAL), cystatin C, urine output, duration of mechanical ventilation, ICU length of stay, AKI, need for dialysis, and mortality. RESULTS AND DISCUSSION: Nineteen studies with 3,395 patients were included in the analyses. The mean bolus and infusion dose of dexmedetomidine were 0.82 µg/kg and 0.54 mcg/kg/hr, respectively. There was a significant difference in creatinine clearance and NGAL in favour of the dexmedetomidine group. In addition, the dexmedetomidine group had a shorter ICU length of stay, and a lower risk of acute kidney injury and mortality compared to the control. There was no difference in the rest of the parameters. WHAT IS NEW AND CONCLUSION: Dexmedetomidine appears to have postoperative renal protective effects. This is evidenced by lower NGAL levels and increased creatinine clearance in those who received dexmedetomidine. These effects are associated with decreases in ICU length of stay and risk of AKI and mortality.

C-reactive protein and procalcitonin after congenital heart surgery utilizing cardiopulmonary bypass: When should we be worried?

INTRODUCTION: To assess the efficacy of C-reactive protein (CRP) and procalcitonin (PCT) at identifying infection in children after congenital heart surgery (CHS) with cardiopulmonary bypass (CPB). MATERIALS AND METHODS: Systematic review of the literature was conducted to identify studies with data regarding CRP and/or PCT after CHS with CPB. The primary variables identified to be characterized were CRP and PCT at different timepoints. The main inclusion criteria were children who underwent CHS with CPB. Subset analyses for those with and without documented infection were conducted in similar fashion. A p value of less than .05 was considered statistically significant. RESULTS: A total of 21 studies were included for CRP with 1655 patients and a total of 9 studies were included for PCT with 882 patients. CRP peaked on postoperative Day 2. A significant difference was noted in those with infection only on postoperative Day 4 with a level of 53.60 mg/L in those with documented infection versus 29.68 mg/L in those without. PCT peaked on postoperative Day 2. A significant difference was noted in those with infection on postoperative Days 1, 2, and 3 with a level of 12.9 ng/ml in those with documented infection versus 5.6 ng/ml in those without. CONCLUSIONS: Both CRP and PCT increase after CHS with CPB and peak on postoperative day 2. PCT has a greater statistically significant difference in those with documented infection when compared to CRP and a PCT of greater than 5.6 ng/ml should raise suspicion for infection.

Importance of D1 and D2 receptor stimulation for the induction and expression of cocaine-induced behavioral sensitization in preweanling rats.

The behavioral manifestations of psychostimulant-induced sensitization vary markedly between young and adult rats, suggesting that the neural mechanisms mediating this phenomenon differ across ontogeny. In this project we examined the importance of D1 and D2 receptors for the induction and expression of cocaine-induced behavioral sensitization during the preweanling period. In the behavioral experiments, rats were injected with reversible D1 and/or D2 antagonists (SCH23390 and/or raclopride) or an irreversible receptor antagonist (EEDQ) either before cocaine administration on the pretreatment day (induction) or before cocaine challenge on the test day (expression). In the EEDQ experiments, receptor specificity was assessed by using selective dopamine antagonists to protect D1 and/or D2 receptors from inactivation. Receptor binding assays showed that EEDQ caused substantial reductions in dorsal striatal D1 and D2 binding sites, while SCH23390 and raclopride fully protected D1 and D2 receptors from EEDQ-induced alkylation. Behavioral results showed that neither D1 nor D2 receptor stimulation was necessary for the induction of cocaine sensitization in preweanling rats. EEDQ disrupted the sensitization process, suggesting that another receptor type sensitive to EEDQ alkylation was necessary for the induction process. Expression of the sensitized response was prevented by an acute injection of a D1 receptor antagonist. The pattern of DA antagonist-induced effects described for preweanling rats is, with few exceptions, similar to what is observed when the same drugs are administered to adult rats. Thus, it appears that maturational changes in D1 and D2 receptor systems are not responsible for ontogenetic differences in the behavioral manifestation of cocaine sensitization.