Ultrasound-Guided Pecto-Intercostal Fascial Block for Postoperative Pain Management in Cardiac Surgery: A Prospective, Randomized, Placebo-Controlled Trial.

OBJECTIVE: To explore the effect of pecto-intercostal fascial plane block (PIFB) on postoperative opioid requirements, pain scores, lengths of intensive care unit and hospital stays and incidence of postoperative delirium in cardiac surgical patients. DESIGN: Single- center, prospective, randomized (1:1), quadruple- blinded, placebo-controlled trial. SETTING: Single center, tertiary- care center. PARTICIPANTS: The study comprised 80 adult cardiac surgical patients (age >18 y) requiring median sternotomy. INTERVENTION: Patients were randomly assigned to receive ultrasound-guided PIFB, with either 0.25% bupivacaine or placebo, on postoperative days 0 and 1. MEASUREMENTS AND MAIN RESULTS: Of the 80 patients randomized, the mean age was 65.78 ± 8.73 in the bupivacaine group and 65.70 ± 9.86 in the placebo group (p = 0.573). Patients receiving PIFB with 0.25% bupivacaine showed a statistically significant reduction in visual analog scale scores (4.8 ± 2.7 v 5.1 ± 2.6; p < 0.001), but the 48-hour cumulative opioid requirement computed as morphine milligram equivalents was similar (40.8 ± 22.4 mg v 49.1 ± 26.9 mg; p = 0.14). There was no difference in the incidence of postoperative delirium between the groups evaluated using the 3-minute diagnostic Confusion Assessment Method (3/40 [7.5%] v 5/40 [12.5%] placebo; p = 0.45). CONCLUSION: Patients who received PIFB with bupivacaine showed a decline in cumulative opioid consumption postoperatively, but this difference between the groups was not statistically significant. Low incidence of complications and improvement in visual analog scale pain scores suggested that the PIFB can be performed safely in this population and warrants additional studies with a larger sample size.

Decreased PGC-1α Post-Cardiopulmonary Bypass Leads to Impaired Oxidative Stress in Diabetic Patients.

BACKGROUND: The mechanism of mitochondrial dysfunction after cardiopulmonary bypass (CPB) in patients with diabetes mellitus lacks understanding. We hypothesized that impaired beta-oxidation of fatty acids leads to worsened stress response in this patient population after cardiac surgery. METHODS: After Institutional Review Board approval, right atrial tissue samples were collected from 35 diabetic patients and 33 nondiabetic patients before and after CPB. Patients with glycated hemoglobin of 6.0 or greater and a clinical diagnosis of diabetes mellitus were considered to be diabetic. Immunoblotting and microarray analysis were performed to assess protein and gene expression changes. Blots were quantified with ImageJ and analyzed using one-way analysis of variance with multiple Student's t test comparisons after normalization. All p values less than 0.05 were considered significant. Immunohistochemistry was performed for cellular lipid deposition assessment. RESULTS: Diabetic patients had significantly lower levels of PGC-1α before and after CPB (p < 0.01 for both) compared with nondiabetic patients. Several upstream regulators of PGC-1α (SIRT1 and CREB) were significantly higher in nondiabetic patients before CPB (p = 0.01 and 0.0018, respectively). Antioxidant markers (NOX4 and GPX4), angiogenic factors (TGF-ß, NT3, and Ang1), and the antiapoptotic factor BCL-xL were significantly lower in diabetic patients after CPB (p < 0.05). The expression of genes supporting mitochondrial energy production (CREB5 and SLC25A40) and angiogenic genes (p < 0.05) was significantly downregulated in diabetic patients after CPB. Immunohistochemistry results showed significantly increased lipid deposition in diabetic myocardial tissue. CONCLUSIONS: Decreased PGC-1α in diabetic patients may lead to impaired mitochondrial function and attenuated antiapoptotic and angiogenic responses after CPB. Therefore, PGC-1α and upstream regulators could serve as a target for improving beta-oxidation in diabetic patients.