Origin and Use of Hydrogen Peroxide in Neurosurgery

Off-site production of plasma-activated water for efficient disinfection: The crucial role of high valence NOx and new chemical pathways

Efficient disinfection of pathogens is a critical concern for environmental disinfection and clinical anti-infective treatment. Plasma-activated water (PAW) is a promising alternative to chemical disinfectants and antibiotics for its strong disinfection ability and not inducing any acute toxicity. Previous plasma sources are commonly placed near or fully in contact with water as possible for more efficient activation, but the risk of electrode corrosion and metal particle contamination of water threatens the safety and stability of PAW. In this work, plasma-activated gas (PAG) rich in high-valence NOx is generated by a hybrid plasma configuration and introduced into water for off-site PAW production. It is found that plasma-generated O3 dominates the gas-phase reactions for the formation of high-valence NOx. With the time-evolution of O3 concentration, the gaseous NO3 radicals are produced behind N2O5 formation, but will be decomposed before N2O5 quenching. By decoupling the roles of gaseous NO3, N2O5, and O3 in the water activation, results show that short-lived aqueous species induced by gaseous NO3 radicals play the most crucial role in PAW disinfection, and the acidic environment induced by N2O5 is also beneficial for microbial inactivation. Moreover, SEM photographs and biomacromolecule leakage assays demonstrate that PAW disrupts the cell membranes of bacteria and thus achieves inactivation. In real-life applications, an integrated device for off-site PAW production with a yield of 2 L/h and a bactericidal efficiency of >99.9 % is developed. The PAW of 50 mL produced in 3 min using this device is more effective in disinfection than 0.5 % NaClO and 3 % H2O2 with the same bacterial contact time. Overall, this work provides new avenues for efficient PAW production and deepens insights into the fundamental chemical processes that govern the reactive chemistry in PAW for environmental and biomedical applications.

History and Use of Antibiotic Irrigation for Preventing Surgical Site Infection in Neurosurgery: A Scoping Review

BACKGROUND

Surgical site infections (SSIs) are surgical complications leading to increased antibiotic usage, higher rates of readmission, prolonged hospitalization, and repeat operations. Use of intraoperative antibiotic irrigation as a form of SSI prophylaxis in neurosurgery may have potential. We aim to review the literature surrounding antibiotic irrigation usage in neurosurgical operations to guide current practice and inform future recommendations.

METHODS

We performed a scoping review of the literature search on PubMed, Ovid, Cochrane, Web of Science, and ClinicalTrials.gov using the terms: ("Neurosurgery" or "Cranial" or "Spinal") and "Antibiotic" and "Irrigation." Data, results, and conclusions were extracted from these studies, analyzed, and summarized.

RESULTS

Seventeen studies were included. The use of antibiotic irrigation was first popularized in 1979 with the use of streptomycin irrigation by Leonard Malis. Fourteen studies compared SSI rates with a control or historical cohort, and 13 of these studies demonstrated a decrease in SSI rate with antibiotic irrigation. There was greater efficacy of irrigation with vancomycin, gentamicin, or streptomycin use. Results are limited due to variations in choice of antibiotic, type of procedure, instrumentation, and sites of infection across studies. Adverse events based on specific antibiotic use should also be considered.

CONCLUSIONS

Current evidence supports the utility of antibiotic irrigation in preventing neurosurgical SSIs. However, study variability and limitations reduce the generalizability of these results. Given the high morbidity and cost associated with SSIs, randomized control trials are needed to further clarify the best evidence-based practices regarding antibiotic irrigation use in neurosurgical procedures.

A metal free catalyst for efficient and stable one-step photocatalytic production of pure hydrogen peroxide

Hydrogen peroxide (H2O2) is widely used as a green and clean energy. The pure H2O2 solution has attracted much attention for its special applications in many fields. Photocatalytic water splitting...