Nitrous oxide 50% / Oxygen 50%

Dental anxiety is common among children and frequently leads to avoidance of dental treatment, premature tooth loss, and broader health concerns such as bite misalignment. This systematic review examines nitrous oxide-oxygen (N₂O/O₂) and oral sedation (e.g., midazolam, hydroxyzine) as minimally invasive options for children aged 2-12 years, using the Patient/Population, Intervention, Comparison, and Outcome (PICO) framework to guide analysis. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020, we searched PubMed, Cochrane, and Scopus (2015-2025), including 25 studies (n≈12,500 participants) with randomized controlled trials (RCTs), cohorts, and reviews. Risk of bias was assessed via Risk Of Bias In Non-randomized Studies-of Interventions (ROBINS-I) and A MeaSurement Tool to Assess systematic Reviews 2 (AMSTAR-2); qualitative synthesis was chosen due to heterogeneity. N₂O excelled in mild anxiety (85-92% efficacy, <5% complications like nausea, rapid 30-60 s onset), making it ideal for short procedures with full recovery in five minutes. Oral sedation showed 70-85% success for moderate cases, with midazolam offering strong amnesia but 5-10% paradoxical excitation; hydroxyzine suited low-risk adjuncts. Combinations boosted outcomes to 88-95%, cutting dropouts by 40-50%. Safety was high overall (<5% adverse events), with N₂O safer for outpatient use. Limitations include protocol variability and limited RCTs. Aligned with the American Academy of Pediatric Dentistry (AAPD) guidelines, these methods promote tailored, office-based care to enhance equity and reduce general anesthesia (GA) needs. Future RCTs should standardize metrics and explore adjuncts like dexmedetomidine. In practice, integrating with behavioral techniques fosters better cooperation and lifelong oral health.

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BackgroundDental sedation facilitates care for patients with anxiety, behavioral challenges, pronounced gag reflexes, special healthcare needs, or complex treatment requirements. This review aimed to integrate current evidence into a clinically applicable framework for individualized sedation planning in dental practice.MethodsAn evidence-informed narrative review was conducted using PubMed/MEDLINE, Scopus, Web of Science, and the Cochrane Library, covering primarily January 2014 to September 2025. Literature identification and selection were reported with reference to PRISMA 2020 principles. Clinical guidelines, systematic reviews and meta-analyses, randomized controlled trials, observational studies, and relevant clinical literature were synthesized narratively and organized descriptively according to study design and their principal role in the narrative synthesis.ResultsEvidence supports individualized sedation selection based on patient age, medical and ASA status, airway risk, anxiety and cooperation, procedural requirements, intended sedation depth, clinician competence, and available monitoring and rescue resources. Nitrous oxide-oxygen and midazolam-based techniques are supported for appropriately selected patients requiring minimal-to-moderate sedation. Advanced or deep sedation requires appropriately trained and credentialed personnel, appropriate physiological monitoring, and immediate airway-rescue capability. Dexmedetomidine- and ketamine-based regimens may provide specialized options in selected populations, although protocols and applicability remain heterogeneous. The evidence was integrated into a conceptual framework addressing patient assessment, pharmacological options, monitoring, recovery, and emergency preparedness.ConclusionsNo single sedative drug or administration route is universally optimal for all dental patients. The available evidence supports individualized sedation selection based on patient characteristics, procedural requirements, intended sedation depth, clinician competence, and available monitoring and rescue resources. Nitrous oxide-oxygen and midazolam-based techniques remain well-supported options for appropriately selected patients, whereas advanced or deep sedation should be reserved for appropriately equipped settings with trained and credentialed personnel.

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The aim of this systematic review was to determine the success rate of nitrous oxide-oxygen procedural sedation (NOIS) in dentistry. A systematic digital search was conducted for publications or reports of randomized controlled trials evaluating the clinical performance of NOIS. Abstracts of research papers were screened for suitability, and full-text articles were obtained for those who met the inclusion and exclusion criteria accordingly. The quality of the studies was assessed using the revised Cochrane risk-of-bias tool (RoB 2). A total of 19 articles (eight randomized clinical trials with parallel intervention groups and 11 crossover trials), published between May 1988 and August 2019, were finally selected for this review. The studies followed 1293 patients reporting NOIS success rates, with a cumulative mean value of 94.9% (95% CI: 88.8-98.9%). Thirteen trials were conducted on pediatric populations (1098 patients), and the remaining six were conducted on adults (195 patients), with cumulative efficacy rates of 91.9% (95% CI: 82.5-98.1%) and 99.9% (95% CI: 97.7-100.0%), respectively. The difference was statistically significant (P = 0.002). Completion of treatment and Section IV of the Houpt scale were the most used efficacy criteria. Within the limitations of this systematic review, the present study provides important information on the efficacy rate of NOIS. However, further well-designed and well-documented clinical trials are required and there is a need to develop guidelines for standardization of criteria and definition of success in procedural sedation. Currently, completion of treatment is the most used parameter in clinical practice, though many others also do exist at the same time. To maximize NOIS efficacy, clinicians should strictly consider appropriate indications for the procedure.

Abstract licence: CC BY-NC

BackgroundPatients with hematological malignancies received multiple hypodermic injections of recombinant human granulocyte colony-stimulating factor. Procedural pain is one of the most common iatrogenic causes of pain in patients with hematological malignancies. It is also identified as the most commonly occurring problem in clinical care in the Department of Hematology and Oncology at Shenzhen University General Hospital. However, providing immediate relief from pain induced by hypodermic injection of recombinant human granulocyte colony-stimulating factor remains a major challenge. This trial aims to evaluate the safety and analgesic efficacy of a fixed nitrous oxide/oxygen mixture for patients with hematological malignancies and experiencing procedural pain caused by hypodermic injection of recombinant human granulocyte colony-stimulating factor in the department.MethodsThe nitrous oxide/oxygen study is a single-center, randomized, double-blind, placebo-controlled trial involving patients with hematological malignancies who require hypodermic injections of recombinant human granulocyte colony-stimulating factor for treatment. This trial was conducted in the Hematology and Oncology Department of Shenzhen University General Hospital. A total of 54 eligible patients were randomly allocated to either the fixed nitrous oxide/oxygen mixture group (n = 36) or the oxygen group (n = 18). Neither the investigators nor the patients known about the randomization list and the nature of the gas mixture in each cylinder. Outcomes were monitored at the baseline (T0), immediately after hypodermic injection of recombinant human granulocyte colony-stimulating factor (T1), and 5 min after hypodermic injection of recombinant human granulocyte colony-stimulating factor (T2) for each group. The primary outcome measure was the score in the numerical rating scale corresponding to the highest level of pain experienced during hypodermic injection of recombinant human granulocyte colony-stimulating factor. Secondary outcomes included the fear of pain, anxiety score, four physiological parameters, adverse effects, total time of gas administration, satisfaction from both patients and nurses, and the acceptance of the patients.DiscussionThis study focused on the safety and analgesic efficacy during hypodermic injection of recombinant human granulocyte colony-stimulating factor procedure. Data on the feasibility and safety of nitrous oxide/oxygen therapy was provided if proven beneficial to patients with hematological malignancies during hypodermic injection of recombinant human granulocyte colony-stimulating factor and widely administered to patients with procedural pain in the department.Trial registrationChinese Clinical Trial Register, ChiCTR2200061507. Registered on June 27, 2022. http://www.chictr.org.cn/edit.aspx?pid=170573&htm=4.

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