Cathodic nitriding and anodic polishing of Ti6Al4V alloy by plasma electrolysis

The paper presents the results of studies on modifying the surface of Ti6Al4V titanium alloy by combined exposure to cathodic nitriding and anodic polishing in electrolysis plasma. The morphology and roughness of the surface, microhardness of the modified layer have been investigated. Wear resistance was studied under dry friction conditions. The effect of combined treatment on corrosion resistance of Ti6Al4V alloy was examined by means of potentiodynamic polarization in Ringer’s solution. It has been established that cathodic nitriding at 750 °C for 10 min leads to the hardening of the surface layer up to 820 HV with an increase in roughness by 2 times and wear resistance almost 3 times. Subsequent anodic plasma electrolytic polishing of the nitriding surface in solution of ammonium sulfate leads to a decrease in roughness and friction coefficient with an increase in corrosion resistance.

The effect of acetate Ringer’s solution versus lactate Ringer’s solution on acid base physiology in infants with biliary atresia

Background The choice of the perioperative crystalloid is a key component of the fluid management and must take into account the liver function and the appearing metabolic disorders to avoid increase the liver extra metabolism. The aim of this study is to analyze the effect of acetate Ringer’s solution or lactate Ringer’s solution in biliary atresia patients. Methods We included 68 infant patients aged between 21 ~ 65 d, ASA physical status II or III, who underwent elective Kasai hepatoportoenterostomy, received either AR and LR for intravenous fluid resuscitation according to their group allocation. Lactate concentration, serum electrolytes and pH were noteded before skin incision (T1), end of surgery (T2) and postoperative 12 h. We also recorded the time of operation, stay of hospital, loss of blood and urinary, total volume of infusion of crystalloid. Results Lactate level was significantly higher in Group LR than in Group AR patients at T2 (0.76 ± 0.13 versus 0.57 ± 0.22, P = 0.03). Compared with T3, sodium and chlorine were significantly higher in two groups at T2 (145.2 ± 3.1 versus 143.4 ± 3.4 and 104.6 ± 3.7 versus 105.2 ± 2.1). No significant differences were noted in potassium, HCO3− and calcium. There was no statistically significant difference in pH. No glycopenia was recorded in two groups. No significant difference was noted in administration of vasoactive drug (0.7% versus 1%). Conclusions Resuscitation with AR and LR was associated with similar clinical improvement in infants with biliary atresia. Use of AR reduced the level of lactate comparison with LR.

Comparison of restrictive fluid therapy with goal-directed fluid therapy for postoperative delirium in patients undergoing spine surgery: a randomized controlled trial

Background Postoperative delirium (POD) is a common phenomenon after spinal surgery. Intraoperative fluid management may affect POD. The aim of this study was to compare the effects of restrictive fluid therapy (RF) with those of goal-directed fluid therapy (GDT) on POD. Methods A total of 195 patients aged ≥ 50 years who underwent spinal surgery were randomly divided into two groups: the RF group and the GDT group. In group RF, a bolus of lactated Ringer’s solution was administered at a dose of 5 mL·kg-1 before the induction of anesthesia, followed by a dose of 5 mL·kg-1·h-1 until the end of surgery. For patients in the GDT group, in addition to the initial administration of lactated Ringer’s solution at 5 mL·kg-1, the subsequent fluid therapy was adjusted by using a continuous noninvasive arterial pressure (CNAP) monitoring system to maintain pulse pressure variation (PPV) ≤ 14%. The primary endpoint was the incidence of POD, assessed once daily with the Confusion Assessment Method-Chinese Reversion (CAM-CR) scale at 1–3 days postoperatively. The secondary endpoints were intraoperative fluid infusion volume, urine volume, mean arterial pressure (MAP), heart rate (HR), cardiac index (CI), regional cerebral oxygen saturation (rSO2) value, lactic acid value, and visual analog scale (VAS) pain score at 1–3 days after surgery. Moreover, postoperative complications and the length of hospital stay were recorded. Results The incidence of POD was lower in the GDT group than in the RF group (12.4% vs 4.1%; P = 0.035) in the first 3 days after spine surgery. Compared to group RF, group GDT exhibited a significantly increased volume of intraoperative lactated Ringer’s solution [1500 (interquartile range: 1128 to 1775) mL vs 1000 (interquartile range: 765 to 1300) mL, P < 0.001] and urine volume [398 (interquartile range: 288 to 600) mL vs 300 (interquartile range: 200 to 530) mL, P = 0.012]. Intraoperative MAP, CI and rSO2 values were higher in the GDT group than in the RF group (P < 0.05). Moreover, the length of hospital stay [17.0 (14 to 20) days versus 14.5 (13 to 17.0) days, P = 0.001] was shorter in the GDT group than in the RF group. Conclusions GDT reduced the incidence of POD in middle- and old-aged patients undergoing spinal surgery possibly by stabilizing perioperative hemodynamic and improving the supply and demand of oxygen. Trial registration ChiCTR2000032603; Registered on May 3, 2020.

Significant features of association of hemostasis, electrolytic and acidic alkaline composition parameters using different variants of perioperative infusion therapy

The paper presents that the use of Ringer’s solution in the program of perioperative infusion therapy, compared with the use of an isotonic sterofundin solution, causes statistically significant adverse changes in the parameters of hemostasis, acid-base state and electrolyte composition, with the exception of potassium and sodium, venous blood. Also, the correlation analysis confirmed the relationship of significant adverse changes in the parameters of hemostasis, acid-base state and electrolyte composition of venous blood in patients when using Ringer’s solution in the perioperative infusion therapy program.