Nadir Oxygen Delivery During Pediatric Bypass as a Predictor of Acute Kidney Injury.

BACKGROUND: Cardiac surgery-associated acute kidney injury (CS-AKI) is common in infants and is associated with negative outcomes. Nadir indexed oxygen delivery (DO2i) during cardiopulmonary bypass (CPB) is associated with the occurrence of postoperative CS-AKI, with critical thresholds for DO2i reported to be 262 to 300 mL/min/m2 in adults. However, given that infants have a higher metabolic rate and oxygen demand, the critical DO2i in infants is not comparable with existing adult standards. This study aimed to explore the critical DO2i threshold during pediatric CPB. METHODS: Between March 2019 and April 2020, 106 consecutive infants undergoing cardiac surgery with CPB were admitted to this prospective observational cohort study. The DO2i levels of each patient were monitored during CPB. Pre- and intraoperative factors were tested for independent association with CS-AKI. The postoperative outcomes of patients with or without CS-AKI were compared. RESULTS: In our patient population (n = 83), we identified 25 patients (38.5%) with postoperative CS-AKI. Multivariate analysis revealed 2 independent risk factors for onset of CS-AKI: CPB duration and nadir DO2i. The lowest suitable DO2i during CPB in the present population was 353 mL/min/m2 (sensitivity, 65.6%; specificity, 74.5%). CS-AKI during pediatric CPB remained significantly associated with an increased morbidity, related mainly to a postoperative low cardiac output syndrome, but not to mortality. CONCLUSIONS: The lowest suitable DO2i during CPB in the infant population undergoing cardiac surgery was 353 mL/min/m2. Below this threshold, there was a high probability of inducing CS-AKI.

[Evaluation of adaptation of root canal filled with three obturation techniques in vitro].

OBJECTIVE: To evaluate the adaptation of root canal filled with three obturation techniques in vitro. METHODS: Fifty-seven cleaned and shaped premolars were divided into three groups, each group including 10 single root canal premolars and 9 double root canal premolars, and filled respectively with following techniques: GuttaFlow paste with single master cone (GF group), cold lateral compaction technique with AH plus sealer (LC group), warm vertical compaction technique with AH plus sealer (VC group). The roots were invested and sectioned at 1 mm interval from crown to apex using a microtome saw under water cooling. Both surfaces of the sections were digitally photographed and measured using a stereomicroscope. The number of sections with voids and the area of voids were measured and analyzed. RESULTS: The frequency of sections with voids: VC group (21.4%, 76/355) was significantly lower than GF group (47.7%, 173/363) and LC group (52.6%, 190/361), P < 0.0167. There was no significant difference between GF and LC group (P > 0.0167). The percentage of voids area (AV%): GF group was significantly higher than LC and VC group (P = 0.000, P = 0.008). The median of GF group was 2.67, LC group was 1.55, VC group was 1.01. No significant difference between VC and LC group (P = 0.076). The filling quality of isthmus: 86% (85/99) isthmus were well filled in VC, significantly higher than GF group (55%, 43/78) and LC group (58%, 49/84), P < 0.0167. There was no significant difference between GF and LC group (P > 0.0167). CONCLUSIONS: The adaptation of root canal filled with warm vertical compaction technique was superior to cold lateral compaction technique and GuttaFlow technique.

[The analysis of the content of bile acids in ox-bile powder and goat gall powder of Mongolian medicine].

The present study was to detect and compare the content of bile acids in ox bile powder and goat gall powder of Mongolia medicine by UV. Cholic acid with sulphuric acid were heated and dehydrated, and they produced conjugated double bond. The conjugated bond showed the same absorption peak in the ultraviolet range. The method of ultraviolet spectrophotometry can be used to detect and compare the content of bile acids in ox bile powder and goat gall powder. The result showed that the linear range was 0.003 3-0.016 7 mg x mL(-1) (r = 0.999 7). The average recovery (n = 5) of standard addition method of ox bile powder and goat gall powder was 98.48% (RSD = 1.79%) and 96.46% (RSD = 2.50%) respectively. The result of determination of five different samples showed that the content of bile acids in ox bile powder and goat gall powder was 40.85%-43.03% and 30.88%-32.64% respectively. The RSD of the analysis of ox bile powder and goat ball powder was 2.40% and 2.92% respectively, the RSD of stationary test of ox bile powder and goat ball powder in eight hours was 0.55% and 0.59% respectively, and the RSD of reproducibility of the analysis of ox bile powder and goat ball powder was 2.11% and 2.68% respectively. The method was simple, accurate, fast and easy to generalize and apply in many fields. It can be used to control the quality of ox bile powder and goat gall powder.