Bupivacaine-fentanyl isobaric spinal anesthesia reduces the risk of ICU admission in elderly patients undergoing lower limb orthopedic surgery.

BACKGROUND: To evaluate if bupivacaine-fentanyl isobaric spinal anesthesia could reduce the risk of ICU admission compared with general anesthesia in elderly patients undergoing lower limb orthopedic surgery. METHODS: This study comprised a retrospective review of all lower limb orthopedic surgeries performed at our hospital between January 2013 and December 2019. According to anesthesia methods, patients were divided into the spinal anesthesia group (n = 1,728) and the general anesthesia group (n = 188). The primary outcome evaluated was the occurrence of ICU admission. Secondary outcomes included hemodynamic changes, postoperative complications, and mortality. RESULTS: Repeated measure analysis of variance indicated that the difference between the two groups in the systolic blood pressure (SBP) was not significant before anesthesia (T0), immediately after anesthesia (T1), and before leaving the operation room (T8) (P > 0.05), but significant (P < 0.01) from 5 min after anesthesia (T2) to after operation (T7). The proportions of ICU admission (6.4% vs. 23.8%, P < 0.01) and unplanned intubation (0.1% vs. 3.8%, P < 0.01) were significantly lower in the spinal anesthesia group compared with those in the general anesthesia group. Multivariate logistic regression revealed that after controlling for potential confounding factors, the odds of ICU admission for patients in the spinal anesthesia group was 0.240 times (95% CI 0.115-0.498; P < 0.01) than those in the general anesthesia group. CONCLUSIONS: Bupivacaine-fentanyl isobaric spinal anesthesia significantly reduced the risk of ICU admission and unplanned intubation, and provided better intraoperative hemodynamics in elderly patients undergoing lower limb orthopedic surgery. TRIAL REGISTRATION: This study has been registered in the Chinese Clinical Trial Registry (ChiCTR2000033411).

Nano-Polycrystalline Cu Layer Interlaced with Ti3+-Self-Doped TiO2 Nanotube Arrays as an Electrocatalyst for Reduction of Nitrate to Ammonia.

The electrochemical nitrate reduction reaction (NO3RR) is considered as a promising strategy to degrade nitrate-containing wastewater and synthesize recyclable ammonia at atmospheric pressure and room temperature. In this work, the copper oxides-derived nano-polycrystalline Cu (NPC Cu) was integrated with Ti3+-self-doped TiO2 nanotube arrays (NTA) to fabricate the NPC Cu/H-TiO2 NTA. Ti3+-self-doped TiO2 NTAs and the NPC Cu facilitate electron transfer and mass transportation and create abundant active sites. The unique nanostructure in which Cu nano-polycrystals interlace with the TiO2 nanotube accelerates the electron transfer from the substrate to surface NPC Cu. The density functional theory calculations confirm that the built-in electric field between Cu and TiO2 improves the adsorption characteristic of the NPC Cu/H-TiO2 NTA, thereby converting the endothermic NO3- adsorption step into an exothermic process. Therefore, the high NO3- conversion of 98.97%, the Faradic efficiency of 95.59%, and the ammonia production yield of 0.81 mg cm-2 h-1 are achieved at -0.45 V vs reversible hydrogen electrode in 10 mM NaNO3 (140 mg L-1)-0.1 M Na2SO4. This well-designed NPC Cu/H-TiO2 NTA as an effective electrocatalyst for the 8e- NO3RR possesses promising potential in the applications of ammonia production.