Practice Patterns and Adverse Events of Nitrous Oxide Sedation and Analgesia: A Report from the Pediatric Sedation Research Consortium

Associations with early vomiting when using intranasal fentanyl and nitrous oxide for procedural sedation in children: A secondary analysis of a randomised controlled trial

OBJECTIVE

Intranasal (IN) fentanyl and nitrous oxide (N2O) can be combined to provide procedural sedation and analgesia to children. This combination is advantageous because of rapid onset of action and non-parenteral administration, but is associated with increased vomiting. We sought to describe the associations of demographic and procedural factors with early vomiting when using this combination in children.

METHODS

This was a planned secondary analysis of a randomised controlled trial comparing the effect of oral ondansetron versus placebo at a single paediatric hospital. Children aged 3 to <18 years with planned procedural sedation with IN fentanyl and N2O were randomised to receive oral ondansetron or placebo prior to N2O administration. Vomiting was defined as early if occurring during or up to 1 h after N2O delivery. We assessed the relationship between early vomiting, demographic and procedural characteristics.

RESULTS

Participants were recruited between October 2016 and January 2019 and 62 out of 436 (14%) had early vomiting. The risk of early vomiting was 30% higher with higher total dose of fentanyl, risk ratio = 1.3 (95% confidence interval = 1.004-1.59). There was little evidence of a relationship between the occurrence of early vomiting and sex, age, weight, type of procedure, fasting duration, time between fentanyl administration and start of procedure, and procedure duration.

CONCLUSION

We found that higher doses of IN fentanyl were associated with higher risk of early vomiting when administered with N2O in children. Other factors did not appear to be associated with vomiting.

Administration of Nitrous Oxide by Medical Assistants for Painful Procedures in Outpatient Pediatric Settings

BACKGROUND

Managing pain and distress in children experiencing procedural pain is a priority in pediatric care. Nitrous oxide (pre-mixed formulation of 50% nitrous oxide to 50% oxygen) is widely used to alleviate anxiety or pain during care procedures in various medical domains. This pharmacological intervention is safe to administer to children. Administration by non-anesthesiologist personnel is widespread throughout the world, though it is almost exclusively performed by doctors and nurses. The purpose of this study is to describe the experience of nitrous oxide (N2O) use by medical assistants and safe handling during the performance of painful procedures.

METHODS

A retrospective study was conducted in a pediatric outpatient unit of a regional hospital, including medical and surgical consultations.

RESULTS

Nitrous oxide was administered by medical assistants to 324 children aged 3 to 19 years. No respiratory and/or cardiovascular problems were noted. Most patients were calm and relaxed.

DISCUSSION

The use of N2O for minor procedures in children in a pediatric outpatient unit improved pain management through administration by medical assistants with a high level of satisfaction from patients, parents and health professionals.

CONCLUSIONS

This study suggests that the use of nitrous oxide by trained medical assistants can be safe, feasible and effective within the specific context of this study.

Strategies to minimize procedure-related pain and anxiety: lessons from pediatric dermatology

PURPOSE OF REVIEW

Recent studies have suggested that prolonged or repeated episodes of general anesthesia early in childhood may adversely affect neurodevelopment. This, combined with rising healthcare costs and decreasing access, has sparked interest in performing pediatric procedures in the office setting when possible. It is essential to address the physical and psychological discomfort that often accompany this experience, particularly in children.

RECENT FINDINGS

Healthcare providers performing procedures on children can draw from a spectrum of established techniques, new technology, and novel use of medications to decrease peri-procedural pain and anxiety. These techniques include distraction, optimization of local anesthesia, and mild to moderate sedation.

SUMMARY

We recommend using a combination of techniques to minimize pain and anxiety to improve safety, decrease healthcare costs, improve patient experience, and prevent childhood trauma and persistent negative perception of the healthcare system.

Safety and efficacy of a nitrous oxide procedural sedation programme in a paediatric emergency department: a decade of outcomes

BACKGROUND

Nitrous oxide (N2O) has multiple benefits in paediatric procedural sedation (PPS), but use is restricted by its limited analgesic properties. Analgesic potency could be increased by combining N2O and intranasal fentanyl (INF). We assessed safety and efficacy data from 10 years (2011-2021) of our N2O PPS programme.

METHODS

Prospectively collected data from a sedation registry at a paediatric emergency department (PED) were reviewed. Total procedures performed with N2O alone or with INF, success rate, sedation depth and adverse events were determined. Contributing factors for these outcomes were assessed via regression analysis and compared between different N2O concentrations, N2O in combination with INF, and for physician versus nurse administered sedation. A post hoc analysis on factors associated with vomiting was also performed.

RESULTS

831 N2O procedural sedations were performed, 358 (43.1%) involved a combination INF and N2O. Nurses managed sedation in 728 (87.6%) cases. Median sedation depth on the University of Michigan Sedation Scale was 1 (IQR 1-2). Sedation was successful in 809 (97.4%) cases. Combination INF/N2O demonstrated higher median sedation scores (2 vs 1, p<0.001) and increased vomiting (RR 1.8, 95% CI 1.3 to 2.5), with no difference in sedation success compared with N2O alone. No serious adverse events (SAEs) were reported (desaturation, apnoea, aspiration, bradycardia or hypotension) regardless of N2O concentration or use of INF. 137 (16.5%) minor adverse events occurred. Vomiting occurred in 113 (13.6%) cases and was associated with higher concentrations of N2O and INF use, but not associated with fasting status. There were no differences in adverse events (RR 0.98, 95% CI 0.97 to 1.04) or success rates (RR 0.93, 95% CI 0.56 to 1.7) between physician provided and nurse provided sedation.

CONCLUSION

N2O can provide effective PED PPS. No SAEs were recorded. INF may be an effective PPS adjunct but remains limited by increased rates of vomiting.

Nitrous oxide use in Canadian pediatric emergency departments: a survey of physician's knowledge, attitudes, and practices

OBJECTIVES

Nitrous oxide (N2O) is an inhaled analgesic/ anxiolytic gas with evidence supporting its safety and efficacy for distressing procedures in children. Despite this, its use is not consistent across Canadian pediatric emergency departments (EDs). We aimed to characterize a) physicians' knowledge and practices with N2O and b) site-specific N2O protocols in Canadian pediatric EDs to help optimize its use nationally.

METHODS

This cross-sectional survey was distributed to physician members of Pediatric Emergency Research Canada (PERC) in early 2021. Survey items addressed practice patterns, clinician comfort, and perceived barriers/ facilitators to use. Further, a representative from each ED completed a site-specific inventory of N2O policies and procedures.

RESULTS

N2O was available in 40.0% of 15 pediatric EDs, with 83.3% of these sites having written policies in place. Of 230 distributed surveys, 67.8% were completed with mean (SD) attending experience of 14.7 (8.6) years and 70.1% having pediatric emergency subspecialty training. Of the 156 respondents, 48.7% used N2O in their clinical practice. The most common indications for use were digit fracture/ dislocation reduction (69.7%), wound closure (60.5%), and incision & drainage (59.2%). Commonly perceived facilitators were N2O equipment availability (73.0% of 156) and previous clinical experience (71.7% of 156). Of the 51.3% of physicians who reported not using N2O, 93.7% did not have availability at their site; importantly, the majority indicated a desire to acquire access. They identified concerns about ventilation/ scavenging systems (71.2% of 80) and unfamiliarity with equipment (52.5% of 80) as the most common barriers to use.

CONCLUSIONS

Despite evidence to support its use, only half of Canadian pediatric ED physicians surveyed use N2O in their clinical practice for treating procedure-related pain and distress. Increased availability of N2O equipment, protocols, and training may improve clinicians' abilities to better manage pediatric acute pain and distress in the ED.

Effects of Low-Concentration Nitrous Oxide Anesthesia on Patient Anxiety During Cataract Surgery: A Retrospective Cohort Study

Purpose

We investigated the effects of 30% low-concentration nitrous oxide (N₂O) anesthesia on anxiety, pain, and vital signs and the patient population that would benefit from low-concentration N₂O anesthesia during cataract surgery.

Patients and Methods

Sixty-three patients who underwent cataract surgery due to visual impairment from cataracts were included in this single-center retrospective cohort study conducted at the Ophthalmology Department of Shinseikai Toyama Hospital, Japan. Fifty eyes of 39 patients received a combination of local and N₂O anesthesia (N₂O group), and 30 eyes of 24 patients received local anesthesia without N₂O anesthesia (Air group). The primary outcome measures were visual analogue scale (VAS) scores for patient anxiety, pain, and vital signs. The secondary outcome measures were the patient population.

Results

The change in the VAS scores for anxiety and pain decreased significantly (p = 0.002 and p = 0.014, respectively) in the N₂O group (−15.6 ± 22.9 and 12.4 ± 14.9, respectively) compared with that in the Air group (1.2 ± 20.6 and 24.2 ± 22.4, respectively). The systolic and diastolic blood pressure changes did not significantly differ between both groups (p = 0.093 and p = 0.23, respectively). The change in heart rate decreased significantly (p = 0.001) in the N₂O group (−4.8 ± 4.8 bpm) compared with that in the Air group (−0.6 ± 5.8 bpm). Multivariate analyses demonstrated that the change in anxiety level in the N₂O group correlated significantly with patient age (p = 0.045) and preoperative VAS score for anxiety (p = 0.0001), whereas the change in anxiety level in the Air group did not correlate with any factor.

Conclusion

Low-concentration N₂O anesthesia showed beneficial effects on intraoperative anxiety and pain during cataract surgery; this may aid the stabilization of intraoperative vital signs. Moreover, low-concentration N₂O anesthesia during cataract surgery could benefit young patients and patients with high levels of preoperative anxiety.

Current status of nitrous oxide use in pediatric patients

Nitrous oxide is one of the most commonly used inhalational anesthetic agents used in practice. It is a cost-effective, pleasant, safe, and versatile anesthetic agent with many desirable properties like good quality analgesia, decreased awareness, accelerated induction and recovery from anesthesia, and reduced utilization of other expensive inhalational agents with potential cost savings. The use of nitrous oxide has been questioned by a lot of studies and case reports perceiving its adverse systemic, hematological, immune, and neurologic adverse effects. However, the literature in the recent past has tried to resolve the controversies related to its use. The concerns over an increase in cardiovascular complications and mortality following nitrous oxide use have been negated by recent data. However, its use in certain vulnerable populations like children with cobalamin and folate deficiency or defects in their metabolic pathways remains a cause of concern for its toxic effects. In this narrative review, we aim to discuss the pharmacological properties of nitrous oxide, the potential advantages and drawbacks of the use of nitrous oxide in children, address the neurodevelopmental and other systemic effects, and throw light on the evidence regarding the safety of nitrous oxide use and its current role in pediatric procedural sedation and anesthesia practice. The literature related to its use in the pediatric population for painful procedures and surgeries has been summarized.

Disruption of Rapid Eye Movement Sleep Homeostasis in Adolescent Rats after Neonatal Anesthesia

BACKGROUND

Previous studies suggest that rapid eye movement sleep rebound and disruption of rapid eye movement sleep architecture occur during the first 24 h after general anesthesia with volatile anesthetics in adult rats. However, it is unknown whether rapid eye movement sleep alterations persist beyond the anesthetic recovery phase in neonatal rats. This study tested the hypothesis that rapid eye movement sleep disturbances would be present in adolescent rats treated with anesthesia on postnatal day 7.

METHODS

Forty-four neonatal rats were randomly allocated to treatment with anesthesia consisting of midazolam, nitrous oxide, and isoflurane or control conditions for 2 h or 6 h. Electroencephalographic and electromyographic electrodes were implanted and recordings obtained between postnatal days 26 and 34. The primary outcome was time spent in rapid eye movement sleep. Data were analyzed using two-tailed unpaired t tests and two-way repeated measures analysis of variance.

RESULTS

Rats treated with midazolam, nitrous oxide, and isoflurane exhibited a significant increase in rapid eye movement sleep three weeks later when compared with control rats, regardless of whether they were treated for 2 h (174.0 ± 7.2 min in anesthetized, 108.6 ± 5.3 in controls, P < 0.0001) or 6 h (151.6 ± 9.9 min in anesthetized, 108.8 ± 7.1 in controls, P = 0.002).

CONCLUSIONS

Treatment with midazolam, nitrous oxide, and isoflurane on postnatal day 7 increases rapid eye movement sleep three weeks later in rats.

La gestion de la douleur et de l’anxiété chez les enfants lors de brèves interventions diagnostiques et thérapeutiques

Les interventions médicales courantes utilisées pour évaluer et traiter les patients peuvent causer une douleur et une anxiété marquées. Les cliniciens devraient adopter une approche de base pour limiter la douleur et l’anxiété chez les enfants, notamment à l’égard des interventions diagnostiques et thérapeutiques fréquentes. Le présent document de principes est axé sur les nourrissons, les enfants et les adolescents qui subissent des interventions médicales courantes mineures, mais douloureuses. Il n’aborde pas les soins prodigués à l’unité de soins intensifs néonatale. Les auteurs examinent des stratégies simples et fondées sur des données probantes pour gérer la douleur et l’anxiété et donnent des conseils pour en faire un volet essentiel de la pratique clinique. Les professionnels de la santé sont invités à utiliser des façons de procéder peu invasives et, lorsque les interventions douloureuses sont inévitables, à combiner des stratégies simples de réduction de la douleur et de l’anxiété pour améliorer l’expérience du patient, du parent et du professionnel de la santé. Les administrateurs de la santé sont encouragés à créer des politiques pour leurs établissements, à améliorer la formation et l’accès aux lignes directrices, à créer des environnements propices aux enfants et aux adolescents, à s’assurer de la disponibilité du personnel, de l’équipement et des agents pharmacologiques appropriés et à effectuer des contrôles de qualité pour garantir une gestion de la douleur optimale.

Managing pain and distress in children undergoing brief diagnostic and therapeutic procedures

Common medical procedures to assess and treat patients can cause significant pain and distress. Clinicians should have a basic approach for minimizing pain and distress in children, particularly for frequently used diagnostic and therapeutic procedures. This statement focuses on infants (excluding care provided in the NICU), children, and youth who are undergoing common, minor but painful medical procedures. Simple, evidence-based strategies for managing pain and distress are reviewed, with guidance for integrating them into clinical practice as an essential part of health care. Health professionals are encouraged to use minimally invasive approaches and, when painful procedures are unavoidable, to combine simple pain and distress-minimizing strategies to improve the patient, parent, and health care provider experience. Health administrators are encouraged to create institutional policies, improve education and access to guidelines, create child- and youth-friendly environments, ensure availability of appropriate staff, equipment and pharmacological agents, and perform quality audits to ensure pain management is optimal.

Results from the Adverse Event Sedation Reporting Tool: A Global Anthology of 7952 Records Derived from >160,000 Procedural Sedation Encounters

Background: The incidence of sedation-related adverse events, inclusive of both adults and children, administered by multiple specialty providers from different countries and venues, using standardized definitions, has never been reported on an international level. We are reporting the outcome data of the adverse event sedation reporting tool as an important step toward a more complete risk assessment of sedation-related morbidity, mortality, and etiology. The analysis of the AE sedation reporting data include descriptive measures to evaluate the characteristics of the provider, the patient, sedations performed, adverse events, interventions, and outcomes. The primary outcome was the rate and nature of adverse events. Between 12/14/2010 and 12/11/2018 there were 7952 sedations, from an estimated total of 164,114 sedations administered, of which 622 were reported as adverse events. The mean age of the entire patient population is 33.0 years (0.02–98.7). The providers represented 39 countries across six continents. Oxygen desaturation (75%–90%) for <60 s is the most prevalent adverse event with a rate of 7.8 per 10,000, followed by airway obstruction at a rate of 5.42 per 10,000. Apnea occurred at a rate of 4.75 per 10,000. Significant predictors of adverse events are ≥ ASA score III (p = 0.0003), procedure time (6:00 pm–12:00 am: p < 0.0001, 12:00–6:00 am: p = 0.0003), and non-hospital location (p < 0.0001). The AE sedation reporting tool has demonstrated that the majority of adverse events in children and adults who receive procedural sedation from multi-specialists internationally required minor interventions and had outcomes of minor risk.

Nitrous Oxide 70% for Procedural Analgosedation in a Pediatric Emergency Department-With or Without Intranasal Fentanyl?

OBJECTIVES

Nitrous oxide 70% (N20 70%) is an excellent medication for procedural analgosedation in a pediatric emergency department. However, its analgesic efficacy remains uncertain for painful procedures; therefore, a combination with intranasal fentanyl (INF), an opioid, was suggested. This study aimed at observing and assessing the analgesic efficacy and rate of adverse events using N20 70% with and without INF.

METHODS

Children who received N20 70% in a tertiary children's hospital emergency department from January 1, 2014 to June 30, 2015 were included in this observational study with prospective data collection. Physicians decided individually whether INF was administered. Medical staff documented the child's behavior during the procedure, adverse events, and satisfaction rate.

RESULTS

A total of 442 children were included; 206 (46.6%) received INF. Group differences regarding patient behavior were not statistically significant; however, N20 70% application time was longer in the INF group (P = .02). Nausea was the most frequent adverse event with 13.1% in the INF group versus 8.1% without INF. Inadequate procedural analgosedation was documented only in the INF group, affecting 1.8% of all patients (P = .002). In contrast, anxiety was exclusively observed in the group without INF, which was presumably misjudged pain (P = .03); the satisfaction rate in the INF group was 95.6% compared with 98.7% without INF.

CONCLUSIONS

Because of the study design and limitations, no conclusions about adding INF to N20 70% can be made. Additional research is needed to investigate the effect of combining N20 70% with INF.

The pearls of pediatric sedation: polish the old and embrace the new

Over the past decade, as the complexity and breadth of pediatric procedures increases, the actual choices of approved sedatives have remained relatively stagnant. Since the introduction of midazolam, there has not been a sedative approved for pediatric labelling until December 2018. This December, the European approval of ADV6209 (Ozalin) for pediatric usage marked the newest addition to the pediatric sedative armamentarium in over a decade. This review is timely and significant because it will provide a balanced evaluation of the most common sedatives in use today, the most recent sedative to be approved and, most importantly, a critical look at the literature supporting the latest approaches to the most commonly performed procedures.

European Society of Anaesthesiology Task Force on Nitrous Oxide: a narrative review of its role in clinical practice

Nitrous oxide (N₂O) is one of the oldest drugs still in use in medicine. Despite its superior pharmacokinetic properties, controversy remains over its continued use in clinical practice, reflecting in part significant improvements in the pharmacology of other anaesthetic agents and developing awareness of its shortcomings. This narrative review describes current knowledge regarding the clinical use of N₂O based on a systematic and critical analysis of the available scientific literature. The pharmacological properties of N₂O are reviewed in detail along with current evidence for the indications and contraindications of this drug in specific settings, both in perioperative care and in procedural sedation. Novel potential applications for N₂O for the prevention or treatment of chronic pain and depression are also discussed. In view of the available evidence, we recommend that the supply of N₂O in hospitals be maintained while encouraging its economic delivery using modern low flow delivery systems. Future research into its potential novel applications in prevention or treatment of chronic conditions should be pursued to better identify its role place in the developing era of precision medicine.

Complications caused by nitrous oxide in dental sedation

The first clinical application of nitrous oxide (N₂O) was in 1844, by an American dentist named Horace Wells who used it to control pain during tooth extraction. Since then, N₂O has shared a 170-year history with modern dental anesthesia. N₂O, an odorless and colorless gas, is very appealing as a sedative owing to its anxiolytic, analgesic, and amnestic properties, rapid onset and recovery, and, in particular, needle-free application. Numerous studies have reported that N₂O can be used safely and effectively as a procedural sedation and analgesia (PSA) agent. However, N₂O can lead to the irreversible inactivation of vitamin B12, which is essential for humans; although rare, this can be fatal in some patients.

Past, present, and future of nitrous oxide

INTRODUCTION

For a drug that has been omnipresent for nearly 200 years, nitrous oxide's (N2O) future seems less certain than its illustrious past. Environmental concerns are coming to the fore and may yet outweigh important clinical benefits.

SOURCES OF DATA

After determining the scope of the review, the authors used PubMed with select phrases encompassing the words in the scope. Both preclinical and clinical reports were considered.

AREAS OF AGREEMENT

The analgesic and anaesthetic advantages of N2O remain despite a plethora of newer agents.

AREAS OF CONTROVERSY

N2O greenhouse gas effect and its inhibition of key enzymes involved in protein and DNA synthesis have provided further fuel for those intent on eliminating its further clinical use.

GROWING POINTS

The use of N2O for treatment-resistant depression has gained traction.

AREAS TIMELY FOR DEVELOPING RESEARCH

Comparative studies for N2O role in combatting the prescription opioid analgesic epidemic may well provide further clinical impetus.

Protocol for a double blind, randomised placebo-controlled trial using ondansetron to reduce vomiting in children receiving intranasal fentanyl and inhaled nitrous oxide for procedural sedation in the emergency department (the FON trial)

INTRODUCTION

Intranasal fentanyl and nitrous oxide (N₂O) can be combined to create a non-parenteral procedural sedation regimen for children in the paediatric emergency department. This combination of intranasal fentanyl and N₂O provides effective pain relief for more painful procedures, but is associated with a higher incidence of vomiting than N₂O alone. Our aim is to assess whether ondansetron used preventatively reduces the incidence of vomiting associated with intranasal fentanyl and N₂O for procedural sedation compared with placebo.

METHODS AND ANALYSIS

This study is a double blind, randomised placebo-controlled superiority trial. This is a single-centre trial of 442 children aged 3-18 years presenting to a tertiary care Paediatric Emergency Department at the Royal Children's Hospital (RCH), Melbourne, Australia, requiring procedural sedation with intranasal fentanyl and N₂O. After written consent, eligible participants are randomised to receive ondansetron or placebo along with intranasal fentanyl, 30-60 min prior to N₂O administration. The primary outcome is vomiting during or up to 1 hour after procedural sedation. Secondary outcomes include: number of vomits and retching during procedural sedation, vomiting 1-24 hours after procedural sedation, procedural sedation duration and associated adverse events, procedure abandonment, parental satisfaction and the value parents place on the prevention of vomiting. This trial will allow refinement of a non-parenteral sedation regimen for children requiring painful procedures.

ETHICS AND DISSEMINATION

This study has ethics approval at the RCH, Melbourne, protocol number 36174. The results from this trial will be submitted to conferences and published in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry (ACTRN12616001213437).

Equimolar mixture of nitroux oxyde and oxygen during post-operative physiotherapy in patients with cerebral palsy: A randomized, double-blind, placebo-controlled study

BACKGROUND

The administration of an equimolar mixture of nitrous oxide and oxygen (N2O) is recommended during painful procedures. However, the evaluation of its use during physiotherapy after surgery has not been reported, although pain may hamper physiotherapy efficiency. This study investigated whether the use of N2O improves the efficacy of post-operative physiotherapy after multilevel surgery in patients with cerebral palsy.

METHOD

It was a randomized 1:1, double-blind, placebo-controlled study. All patients had post-operative physiotherapy starting the day after surgery. Patients received either N2O or placebo gas during the rehabilitation sessions. All patients had post-operative pain management protocol, including pain medication as needed for acute pain. The primary objective was to reach angles of knee flexion of 110° combined with hip extension of 10°, with the patient lying prone, within six or less physiotherapy sessions. Secondary evaluation criteria were the number of sessions required to reach the targeted angles, the session-related pain intensity and the analgesics consumption for managing post-operative pain.

RESULTS

Sixty-four patients were enrolled. Targeted angles were achieved more often in the N2O group (23 of 32, 72%, vs. Placebo: 13/ of 32, 41%; p = 0.01).

CONCLUSION

The administration of N2O during post-operative physiotherapy can help to achieve more quickly an improved range of motion, and, although not significant in our study, to alleviate the need for pain medication. Further studies evaluating the administration of N2O in various settings are warranted.

SIGNIFICANCE

During this randomized placebo-controlled double-blind study, children receiving nitrous oxide and oxygen (N2O) achieved more often the targeted range of motion during physiotherapy sessions after multilevel surgery. Compared to placebo, nitrous oxide and oxygen (N2O) enabled a better management of acute pain related to physiotherapy procedures.