Effects of the Prophylactic Use of Amiodarone Infusion to Prevent Postoperative Atrial Fibrillation after Cardiac Surgery

Postoperative atrial fibrillation（AF）is associated with significant morbidity after cardiac surgery. We examined the effects of a prophylactic postoperative amiodarone infusion to prevent postoperative AF. A prospective randomized study was performed in patients with a high risk of postoperative AF between March 2016 and March 2019. High risk of AF was defined as combined valve surgery, aortic valve replacement（age＞70）, or off-pump coronary bypass grafting（age＞65）. Forty-two patients were enrolled and randomly assigned to receive prophylactic amiodarone infusion（amiodarone group, n＝20）or saline infusion（control group, n＝22）. In the amiodarone group, amiodarone was infused intravenously for 48hr postoperatively（initially 125mg/10min, then 288mg/6hr, then maintenance of 1,040mg/42hr）. There were no significant differences between the two groups in age, sex, body height, body weight, surgical procedure, and perioperative use of beta blockers. The occurrence of sustained AF for＞1hr was significantly lower in the amiodarone group（30.0％）than in the control group（63.6％, p＝0.04）. The total duration of AF over one week was also significantly shorter in the amiodarone group（296.8±676.9min）than in the control group（921.4±1641.6min, p＝0.04）, as was the postoperative hospital stay（17.3±6.1 vs. 24.5±11.3 days, respectively, p＝0.01）. There were no major side effects with amiodarone infusion except for one case of bradycardia. These results show the prophylactic use of intravenous amiodarone infusion for the first 48hr of the postoperative period is a safe and effective treatment to prevent postoperative AF after cardiac surgery and to shorten the hospital stay

Factors influencing arterial oxygenation early after bidirectional cavopulmonary shunt without additional sources of pulmonary blood flow

AbstractObjectives: Although the arterial oxygen saturation after bidirectional cavopulmonary shunting should theoretically be homogeneous if additional pulmonary flow is obliterated, the arterial oxygen saturation has been found to vary in clinical practice. Knowledge of the preoperative and operative determinants of arterial oxygen saturation early after bidirectional cavopulmonary shunting may lead to a better understanding of this unique physiology. Methods: Thirty-five patients who underwent bidirectional cavopulmonary shunting with obliteration of additional pulmonary flow were included in this study. The arterial oxygen saturation was determined at the 5 time points over a 48-hour period. Multivariable regression analysis was used to identify the independent predictors of the arterial oxygen saturation. Results: No significant interval changes occurred in the arterial oxygen saturation during the 48 hours after bidirectional cavopulmonary shunting, which ranged from 61.6% to 95.6%. There was a significant inverse correlation between the postoperative superior vena cava pressure and the arterial oxygen saturation (P =.003). A low arterial oxygen saturation early after bidirectional cavopulmonary shunting was a predictor of mortality or exclusion from univentricular repair within 24 months (P =.012, odds ratio = 1.14). Of 11 factors identified by univariable analysis, multiple regression analysis indicated that age less than 8 months at the time of shunting (P <.0001) and ventricular volume overload (P =.002) predicted a lower arterial oxygen saturation after bidirectional cavopulmonary shunting. Conclusions: Even without additional sources of pulmonary blood flow, several preoperative factors, including younger age and severe ventricular volume overload, predicted a decrease in the arterial oxygen saturation early after bidirectional cavopulmonary shunting. This, in turn, predicted poor outcome during 2 years of follow-up. (J Thorac Cardiovasc Surg 2000;120:589-95

Clinical Implications of Determining Individualized Positive End-Expiratory Pressure Using Electrical Impedance Tomography in Post-Cardiac Surgery Patients: A Prospective, Non-Randomized Interventional Study

Optimal positive end-expiratory pressure (PEEP) can induce sustained lung function improvement. This prospective, non-randomized interventional study aimed to investigate the effect of individualized PEEP determined using electrical impedance tomography (EIT) in post-cardiac surgery patients (n = 35). Decremental PEEP trials were performed from 20 to 4 cmH2O in steps of 2 cmH2O, guided by EIT. PEEP levels preventing ventilation loss in dependent lung regions (PEEPONLINE) were set. Ventilation distributions and oxygenation before the PEEP trial, and 5 min and 1 h after the PEEPONLINE setting were examined. Furthermore, we analyzed the saved impedance data offline to determine the PEEP levels that provided the best compromise between overdistended and collapsed lung (PEEPODCL). Ventilation distributions of dependent regions increased at 5 min after the PEEPONLINE setting compared with those before the PEEP trial (mean &plusmn; standard deviation, 41.3 &plusmn; 8.5% vs. 49.1 &plusmn; 9.3%; p &lt; 0.001), and were maintained at 1 h thereafter (48.7 &plusmn; 9.4%, p &lt; 0.001). Oxygenation also showed sustained improvement. Rescue oxygen therapy (high-flow nasal cannula, noninvasive ventilation) after extubation was less frequent in patients with PEEPONLINE &ge; PEEPODCL than in those with PEEPONLINE &lt; PEEPODCL (1/19 vs. 6/16; p = 0.018). EIT-guided individualized PEEP stabilized the improvement in ventilation distribution and oxygenation. Individual PEEP varies with EIT measures, and may differentially affect oxygenation after cardiac surgery

Characteristic β-Globin Gene Cluster Haplotypes of Evenkis and Oroqens in North China

Haplotype frequencies of the β-globin gene cluster were estimated for 114 Evenkis and 81 Oroqens from northeast China, and their characteristics were compared with those in Japanese, Koreans, and three Colombian Amerindian groups of South America (Wayuu, Kamsa, and Inga tribes). A major 5 subhaplotype (5 to the δ-globin gene) was in Evenkis, whereas , , and were the major subhaplotypes in Oroqens. One possible candidate for an ancestral 5 subhaplotype, , was found in one Evenki (0.5%) and three Oroqen chromosomes (2.0%). They were observed as heterozygous forms for and . Major haplotypes were , , and in Evenkis, whereas they were , , , and in Oroqens. The lowest Nei’s genetic distance values of Evenkis or Oroqens based on the 5 subhaplotype frequency distributions were observed in relation to theWayuu or Koreans, respectively, but those of Evenkis and Oroqens based on the haplotype frequency distributions were found in relation to Koreans

beta-globin gene cluster haplotype frequencies in Khalkhs and Buryats of Mongolia

beta-globin gene cluster haplotype frequencies of 169 Khalkhs and 145 Buryats were estimated, and their characteristics were compared with those of Evenkis, Oroqens, Koreans, Japanese, and three Colombian Amerindian groups. The present study suggests that Colombian Amerindians diverged first from Asian populations and then Buryats diverged from other Asian populations.beta-globin gene cluster haplotype frequencies of 169 Khalkhs and 145 Buryats were estimated, and their characteristics were compared with those of Evenkis, Oroqens, Koreans, Japanese, and three Colombian Amerindian groups. The present study suggests that Colombian Amerindians diverged first from Asian populations and then Buryats diverged from other Asian populations