Prospective, double-blind, randomized trial of equimolar mixture of nitrous oxide/oxygen to prevent pain induced by insertion of venous access ports in cancer patients

Nitrous oxide provided during intensive physiotherapy for shoulder adhesive capsulitis does not improve function: A randomised controlled trial

BACKGROUND

There is no consensus on treatment for adhesive capsulitis of the shoulder. Physiotherapy is often used to increase range of motion but individuals may experience pain during mobilisation.

OBJECTIVES

The objective of this study was to determine whether rehabilitation under N2O for shoulder AC improved pain and function more than rehabilitation alone (with placebo gas).

METHOD

A randomised, 1:1 parallel arm, double-blind study in 4 university hospital outpatient centres. Adults with adhesive capsulitis for at least 3 months with intact cartilage were included. Participants were randomised in blocks of 4 and stratified by centre to receive 20 sessions of intensive physiotherapy over 10 days; the 10 morning sessions were performed with either nitrous oxide (intervention) or sham gas (placebo).

PRIMARY OUTCOME

improvement in shoulder function at day 14 (D14) (Constant-Murley score).

RESULTS

Seventy-five participants were included, and data from 69 were analysed: 37 in the placebo group and 32 in the intervention group. Improvements occurred in both groups after the intervention. No significant difference in the Constant-Murley score was found between groups at D14 (median score increase of 12.0, IQR 5.6; 19.5 points in placebo group vs. 13.7, 5.2; 18.2 in the N20 group, p = 0.78). Pain score during sessions reduced in the intervention group from the first to final session (-11.6, p = 0.053) but not for the placebo group (-4.2, p = 0.414). Seven serious adverse events were recorded, 4 in the intervention group and 3 in the placebo group, with 11 minor adverse events only in the intervention group (mostly shortness of breath).

CONCLUSION

Nitrous oxide gas associated with intensive physiotherapy for shoulder adhesive capsulitis did not improve function, pain or quality of life more than physiotherapy alone. zHowever, pain experienced during physiotherapy sessions appeared lower.

TRIAL REGISTRATION

Clinical Trial registration number NCT01087229.

The Use of a Fixed 50:50 Mixture of Nitrous Oxide and Oxygen to Reduce Lumbar Puncture-Induced Pain in the Emergency Department: A Randomized Controlled Trial

Lumbar puncture (LP) is stressful and often painful. We evaluated the efficacy of a fixed 50% nitrous oxide−oxygen mixture (50%N2O-O2) versus placebo to reduce immediate procedural pain and anxiety during LP performed in an emergency setting. We conducted a randomized controlled trial involving adults who needed a cerebrospinal fluid analysis in an emergency department. Patients were randomly assigned to inhale either 50%N2O-O2 or medical air. The primary endpoint, assessed using a numerical scale, was the maximum pain felt by the patient during the procedure and the maximum anxiety and satisfaction as secondary outcomes. Eighty-eight patients were randomized and analyzed (ITT). The maximal pain was 5.0 ± 2.9 for patients receiving air and 4.2 ± 3.0 for patients receiving 50%N2O-O2 (effect-size = −0.27 [−0.69; 0.14], p = 0.20). LP-induced anxiety was 4.7 ± 2.8 vs. 3.7 ± 3.7 (p = 0.13), and the proportion of patients with significant anxiety (score ≥ 4/10) was 72.7% vs. 50.0% (p = 0.03). Overall satisfaction was higher among patients receiving 50%N2O-O2 (7.4 ± 2.4 vs. 8.9 ± 1.6, p < 0.001). No serious adverse events were attributable to 50%N2O-O2 inhalation. Although inhalation of 50%N2O-O2 failed to reduce LP-induced pain in an emergency setting, it tended to reduce anxiety and significantly increased patient satisfaction.

Analgesic gas for rehabilitation of frozen shoulder: Protocol for a randomized controlled trial

BACKGROUND

There is little evidence regarding the best way to treat adhesive capsulitis. Physical therapy can reduce pain and improve function and range of motion. However, we lack clear indications on the regimen, techniques or intensity of physical therapy to achieve better results. Intensive physical therapy seems to be confined to the later stages of adhesive capsulitis (chronic stage) given that rehabilitation-induced pain could worsen the outcomes. Here we describe a protocol for a study comparing the efficacy of a standardized program of intensive mobilization under analgesic gas to a similar program under placebo gas and questioning the impact of pain.

METHOD/DESIGN

A randomized, double-blind, multicenter study - the MEOPA Trial - was designed to include adults with strictly defined clinical adhesive capsulitis for a 14-day intensive physical rehabilitation program under an equimolar mixture of oxygen and nitrous oxide or sham gas administration. Efficacy will be assessed by the Constant-Murley score. Data for secondary criteria including pain, disability, quality of life and perceived efficacy by the patient or physiotherapist will be collected over 6 months.

DISCUSSION

This randomized controlled trial has been designed to test the effectiveness of intensive physical therapy under a simple and safe analgesic method. This study will also address the effect of pain during rehabilitation in adhesive capsulitis. Furthermore, results from the 6-month multidimensional follow-up of painful mobilization for this condition could be extrapolated to other musculoskeletal conditions.

TRIAL REGISTRATION

ClinicalTrials.gov No. NCT01087229.

Randomized controlled trials in central vascular access devices: A scoping review

BACKGROUND

Randomized controlled trials evaluate the effectiveness of interventions for central venous access devices, however, high complication rates remain. Scoping reviews map the available evidence and demonstrate evidence deficiencies to focus ongoing research priorities.

METHOD

A scoping review (January 2006-December 2015) of randomized controlled trials evaluating the effectiveness of interventions to improve central venous access device outcomes; including peripherally inserted central catheters, non-tunneled, tunneled and totally implanted venous access catheters. MeSH terms were used to undertake a systematic search with data extracted by two independent researchers, using a standardized data extraction form.

RESULTS

In total, 178 trials were included (78 non-tunneled [44%]; 40 peripherally inserted central catheters [22%]; 20 totally implanted [11%]; 12 tunneled [6%]; 6 non-specified [3%]; and 22 combined device trials [12%]). There were 119 trials (68%) involving adult participants only, with 18 (9%) pediatric and 20 (11%) neonatal trials. Insertion-related themes existed in 38% of trials (67 RCTs), 35 RCTs (20%) related to post-insertion patency, with fewer trials on infection prevention (15 RCTs, 8%), education (14RCTs, 8%), and dressing and securement (12 RCTs, 7%). There were 46 different study outcomes reported, with the most common being infection outcomes (161 outcomes; 37%), with divergent definitions used for catheter-related bloodstream and other infections.

CONCLUSION

More high quality randomized trials across central venous access device management are necessary, especially in dressing and securement and patency. These can be encouraged by having more studies with multidisciplinary team involvement and consumer engagement. Additionally, there were extensive gaps within population sub-groups, particularly in tunneled devices, and in pediatrics and neonates. Finally, outcome definitions need to be unified for results to be meaningful and comparable across studies.

Fixed 50:50 mixture of nitrous oxide and oxygen to reduce lumbar-puncture-induced pain: a randomized controlled trial

BACKGROUND AND PURPOSE

Lumbar puncture (LP) has been frequently performed for more than a century. This procedure is still stressful and often painful. The aim of the study was to evaluate the efficacy of a fixed 50% nitrous oxide-oxygen mixture compared to placebo to reduce immediate procedural pain and anxiety during LP.

METHODS

A randomized controlled trial was conducted involving adults who needed a cerebrospinal fluid analysis. Patients were randomly assigned to inhale either a fixed 50% nitrous oxide-oxygen mixture (50% N₂ O-O₂ ) or medical air (22% O₂ -78% N₂ ). Cutaneous application of a eutectic mixture of local anaesthetics was systematically done and all LPs were performed with pencil point 25G needles (20G introducer needle). The primary end-point was the maximal pain level felt by the patient during the procedure, the maximal anxiety level being a secondary outcome, both measured using a numerical rating scale (0-10).

RESULTS

A total of 66 consecutive patients were randomized. The analysis was intention to treat. The maximal pain was 4.9 ± 2.7 for the 33 patients receiving air and 2.7 ± 2.7 for the 33 receiving 50% N₂ O-O₂ (P = 0.002). Similarly, the maximal LP-induced anxiety was 4.5 ± 3.1 vs. 2.6 ± 2.6 (P = 0.009), respectively. The number needed to treat to avoid one patient undergoing significant pain (pain score ≥ 4/10) was 2.75. Body mass index >25 kg/m² was significantly associated with higher pain intensity (P = 0.03). No serious adverse events were attributable to 50% N₂ O-O₂ inhalation.

CONCLUSIONS

Inhalation of a fixed 50% N₂ O-O₂ mixture is efficient to reduce LP-induced pain and anxiety.

Applications of nitrous oxide for procedural sedation in the pediatric population

OBJECTIVE

The objective of this review was to provide a general descriptive account of the physical properties, end-organ effects, therapeutic applications, and delivery techniques of nitrous oxide (N2O) as used in the arena of procedural sedation.

DATA SOURCE

A computerized bibliographic search regarding the applications of nitrous for provision of sedation and analgesia during procedures with an emphasis on the pediatric population was performed.

RESULTS

The end-organ effects of N2O have been well described in the operating room setting. Aside from its effects on the central nervous system of sedation and analgesia, N2O may alter intracerebral dynamics and alter cerebral blood flow and intracranial pressure especially in patients with altered intracranial compliance. Effects on ventilation include a dose-related depression of ventilatory function and control of upper airway patency. These effects are generally limited in the absence of comorbid diseases and potentiated by other sedative and analgesic agents. The more clinically significant respiratory effect of N2O on ventilatory function is a dose-dependent depression of the ventilatory response to hypoxemia. Hemodynamic effects include a mild direct depressant effect on myocardial function, which in the absence of comorbid cardiac disease is generally compensated by stimulation of the sympathetic nervous system. Nitrous oxide may potentially aggravate pulmonary hypertension. Additional physiologic effects on neurologic and hematologic function may result in inactivation of the enzyme, methionine synthetase. Recent concern has also been raised regarding the potential effects of N2O on immune function and its relationship to perioperative surgical site infections. Given differences in the solubility, N2O will diffuse into and significantly expand gas-filled cavities. Chronic exposure of health care works to N2O is also a concern. Although there are limited data in the literature to clearly substantiate concerns regarding the reproductive toxicity of occupational exposure to N2O, appropriate scavenging and use of other techniques are mandatory. Nitrous oxide has been shown to be effective for a variety of minor surgical procedures such as venipuncture, intravenous cannula placement, lumbar puncture, bone marrow aspiration, laceration repair, dental care, and minor dermatologic procedures. It is generally as effective as midazolam, with several studies demonstrating it to be more effective. However, its utility is not as great in severely painful procedures such as fracture reduction. Demonstrated advantages to parenteral sedation include a more rapid onset and a shorter recovery time with the majority of patients preferring it to over other agents or agreeing to its use for subsequent procedures. The literature also suggests increased success rates with simple procedures such as intravenous cannula placement when compared with placebo. In general, life-threatening adverse events have not been reported. Most common adverse effects include dysphoria and vomiting. For more painful procedures, combination with another agent may be used, and in all cases, topical or infiltrative local anesthesia is recommended.

CONCLUSIONS

In general, N2O is a useful adjunct for procedural sedation. Given the variety of procedures performed in the pediatric patient, ongoing research is required to identify the most appropriate and effective use of this agent. This may be particularly relevant when evaluating its use for procedures associated with significant pain. In these scenarios, the combination of N2O with other agents needs to be evaluated. Given the potential for adverse effects, strict adherence to published guidelines regarding procedural sedation and monitoring is suggested.

A review of the safety of 50% nitrous oxide/oxygen in conscious sedation

Few studies into conscious sedation with 50% nitrous oxide/oxygen premix (50% N2O/O2) have been conducted in accordance with Good Clinical Practice in Clinical Trials. Of the 140 articles retained in this review, the incidence of adverse events (AEs) varied in the range of 0-68% according to the indications. When other drugs and/or local anaesthesia were used concomitantly, the relative risk for nausea and vomiting increased whereas it decreased for vertigo or hallucinations. Only one study examined potential causal relationship between serious AEs and the 50% N2O/O2 gas itself, giving a risk for a serious AE directly due to the gas of 3/10,000 administrations. No analysis of the effect of the method of administration was possible, nor could conclusions be drawn relating to the risk of occupational exposure.