[Analgesia using a (50/50) mixture of nitrous oxide/oxygen in children]

Analgesia effect of premixed nitrous oxide/oxygen during the rehabilitation after total knee arthroplasty: a study protocol for a randomized controlled trial

Background

The morbidity of knee arthritis is increasing among aged people and total knee arthroplasty has been its mainstream treatment to date. Postoperative rehabilitation is an important part of the procedure. However, the intense pain during the functional exercise involved has always been a challenge for both patients and health care professionals. The aim of this study is to test the analgesic effect of a mixture of nitrous oxide/oxygeb (1:1) inhalation for patients who are doing functional exercise 1 month after total knee arthroplasty.

Methods/design

This double-blind, randomized, placebo-controlled study will be implemented in the Rehabilitation Department in the General Hospital of Ningxia Medical University. Patients aged between 50 and 75 years who underwent a primary unilateral total knee arthroplasty are eligible for inclusion. The key exclusion criteria include: epilepsy, pulmonary embolism, intestinal obstruction, aerothorax. The treatment group (A) will receive a pre-prepared nitrous oxide/oxygen mixture plus conventional treatment (no analgesics), and the control group (B) will receive oxygen plus conventional treatment (no analgesics). Patients, physicians, therapists, and data collectors are all blind to the experiment. Assessments will be taken immediately after functional exercise begins (T0), 5 min (T1) after functional exercise begins, and 5 min after functional exercise has finished (T2). Patients will be randomly allocated between a treatment group (A) and a control group (B) in a ratio of 1:1. Primary outcome, including pain severity in the procedure, will be taken for each group. Secondary outcomes include blood pressure, heart rate, oxygen saturation, side effects, knee joint range of motion, Knee Society Score (KSS), rescue analgesia need, and satisfaction from both therapists and patients.

Discussion

This study will focus on exploring a fast and efficient analgesic for patients who are doing functional exercise after total knee arthroplasty. Our previous studies suggested that the prefixed nitrous oxide/oxygen mixture was an efficacious analgesic for the management of burn-dressing pain and breakthrough cancer pain. The results of this study should provide a more in-depth insight into the effects of this analgesic method. If this treatment proves successful, it could be implemented widely for patients doing functional exercise in the rehabilitation department.

Trial registration

ChiCTR-INR-17012891. Registered on 6 October 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3472-7) contains supplementary material, which is available to authorized users.

[The use of nitrous oxide and oxygen in paediatric emergency departments]

The treatment of pain, particularly in infants, is today a public health priority. The mix of nitrous oxide and oxygen, colloquially known as 'gas and air' is an important analgesia for infants for short, painful procedures. Its fast action and almost immediate reversibility when the child stops inhaling facilitates its use and its tolerance. Subject to a medical prescription, it must be administered by a specially trained member of nursing staff.

Medical workers' cognition of using 50% nitrous oxide in children with burns: a qualitative study

Pain caused by dressing among children with burns is an issue worth discussing. Medical workers' understanding of pain during dressing in children with burns is correlated with the quality of pain management. Effective pain management is significant to improve anxiety and reduce pain and psychological distress during dressing for children with burns. We aimed to investigate medical workers' understanding of current pain management during dressing among children with burns and their attitudes toward the application of 50% nitrous oxide in pain management. Interviews were conducted with seven doctors and nurses from a burn center in East China. Data were collected by in-depth interviews and qualitative description after full transcription of each interview. Three themes were identified: (1) Medical workers felt sympathy for children with burns and believed that a gap existed between the current and expected situation in pain management. In addition, the prescription of analgesics during dressing for children with burns was not favored. (2) Given the fact that 50% nitrous oxide is effective in pain management for adult patients with burns, medical workers tended to apply it to children with burns during dressing after being provided the literature on the use of 50% nitrous oxide in children. (3) Guidelines for the application of 50% nitrous oxide during dressing for children with burns require further modification. Medical workers deemed the pain management for children with burns unsatisfactory, and they supported the application of 50% nitrous oxide during dressing for children with burns. Meanwhile, they hoped that administrators would also support it.

Nitrous oxide-oxygen mixture during care of bedsores and painful ulcers in the elderly: a randomized, crossover, open-label pilot study

Bedsore and ulcer care can often be painful and no standardized analgesic method exists today for pain relief during treatment in adults and the elderly. To evaluate the analgesic efficacy of a nitrous oxide-oxygen mixture vs. morphine during painful bedsore and ulcer care in adult and elderly patients, we conducted a randomized, crossover, multicenter, prospective, open-label, pilot study. Thirty-four inpatients, aged 53-96 years (median 84 years), were recruited in Grenoble University Hospital, Annecy Hospital and Chambéry Hospital, France, from January to June 2001. Each of the 34 patients received morphine (M), nitrous oxide-oxygen mixture (E), or morphine+nitrous oxide-oxygen mixture (ME) during painful care in a crossover protocol. Treatments were changed every two days and the study duration was six days. Analgesia was evaluated before and after each care session using a behavioral scale to evaluate pain in noncommunicating adults (ECPA), a visual analog scale (VAS), a global hetero-evaluation scale (GHES), and the DOLOPLUS-2 scale. There was a significant overall difference (P<0.01) among the three treatments. On the ECPA, the average difference after and before care was +5.2+/-8.6 (M), -0.3+/-8 (E), and -0.6+/-7.4 (ME), respectively. There was a significant difference between M and E, and M and ME (each P<0.01). No difference was found between E and ME (P=0.97). There were similar significant differences in the GHES and DOLOPLUS-2 scales (all tests P<0.01). Post hoc comparisons showed a significant difference (P<0.01) between M and E, and between M and ME without any additional effect for M+E. No differences were found with regard to safety or tolerability. This pilot study demonstrates the superiority of nitrous oxide-oxygen mixture over morphine for analgesia. This experience suggests that this mixture has ease of use, rapid effect, and limited contraindications when used during painful bedsore and ulcer care in elderly patients. Furthermore, it is well accepted by these patients and by nursing staff.

Nitrous oxide inhalation to improve patient acceptance and reduce procedure related pain of flexible cystoscopy for men younger than 55 years

PURPOSE

Flexible cystoscopy in men younger than 55 years is painful despite the current best standard anesthesia (20 ml 2% lidocaine gel 15 minutes before endoscopy). The anesthetic value of lidocaine gel is debated and led us to seek an alternative. Nitrous oxide is a well established analgesic and anxiolytic agent, and it significantly reduces pain associated with transrectal ultrasound guided prostate biopsy. We studied its use in flexible cystoscopy in men younger than 55 years.

MATERIALS AND METHODS

A total of 61 patients were prospectively randomized to receive air (31) or Entonox (30). Both groups had 3 minutes of gas via a breath activated facemask (either Entonox or air) before endoscopy. The gel control group was comprised of 8 patients who underwent cystoscopy after instillation of lidocaine gel. The air and Entonox groups had lidocaine gel as per best standard. Vital signs were recorded before, during and after cystoscopy. Patients completed a visual analog score for gel insertion and cystoscopy.

RESULTS

There were no statistically significant differences between the groups in terms of baseline characteristics. Pain scores for cystoscopy (p<0.001) and intraoperative pulse rate (p=0.008) were significantly less with Entonox. Side effects were transient and seen more often with Entonox (p<0.05). More of the air group would require more analgesia (p=0.001) or a general anesthetic (p=0.011) if undergoing repeat cystoscopy.

CONCLUSIONS

Nitrous oxide inhalation significantly reduces cystoscopy related pain without significant complications. We propose that Entonox should be the anesthetic agent of choice for men younger than 55 years.

Nitrous oxide analgesia for intubating preterm neonates: a pilot study

AIM

To evaluate the administration of an equimolar mixture of N2O and O2 for intratracheal intubation in preterm neonates with respiratory distress syndrome (RDS).

DESIGN

Prospective evaluation of N2O/O2 in premature neonates with RDS.

SETTING

Tertiary neonatal unit from March to August 2003.

PATIENTS

Twenty-six of 79 neonates admitted for RDS within 48 h of birth.

INTERVENTION

N2O/O2 was administered until muscle tone was suppressed. Surfactant was given intratracheally. Patients were extubated as soon as possible.

MAIN OUTCOME MEASURES

The time needed for N2O/O2 to suppress muscle tone, an evaluation of sedation/analgesia through movements of the limbs, and indicators of stress-related haemodynamic change, all recorded by an independent observer.

RESULTS

In the 26 patients, gestational age was 30.5 (25th, 75th percentile: 30, 32) wk and median body weight was 1540 (1220, 1900) g. Postnatal age at intubation was 2 (2, 3) h. N2O/O2 administration time was 8 (6, 10) min (range 4-15 min). Sedation/analgesia was complete in 77% of patients. No significant differences between pre-procedure and post-procedure values were found for heart rate (p=0.29) or mean arterial blood pressure (p=0.13) (paired Wilcoxon test). Time needed for intubation was 30 (20, 37) s (range 10-60 s). Side effects included transient agitation (3/26) and retching (2/26). Extubation occurred 5 (5, 10) min (range 2-15 min) after surfactant instillation. Apnoeas occurred in 3/26 patients within 2 h after extubation. Two patients required reintubation to repeat surfactant administration within 24 h after extubation.

CONCLUSION

N2O/O2 may be helpful for intubation in preterm neonates. Larger randomized, double-blind studies are needed for a thorough evaluation of effectiveness and safety.

[Premixed 50% nitrous oxide and oxygen: theoretical recalls and practical modalities]

The concept of premixed 50% nitrous oxide and oxygen dated back to 1961 in England, where it is commercialised under the name Entonox. In France, after a so marginal use, premixed 50% nitrous oxide and oxygen now knows such a revival since we first consider the pain provoked by the cure. To use correctly premixed 50% nitrous oxide and oxygen, we need to know the main properties of the nitrous oxide. The four commercial versions, now on the market, are presented (Kalinox, Medimix, Antasol, Oxynox. Except a few contraindications, these indications are large, as well at hospital as outside. In less than 10% of the cases, side effects are possible. Conditions of administration are given in details. The limits of the technic and the particular precautions of use are precised.

La fibroscopie bronchique chez l’enfant

INTRODUCTION

Fibreoptic bronchoscopy (FB) is an important diagnostic examination in paediatric pulmonology. In 2002 the Paediatric Pulmonology and Allergy Club undertook a retrospective study to establish the current status of fibreoptic bronchoscopy among its members.

METHODS

In 2001 sixty five paediatric pulmonologists carried out an average of 116 examinations (+/- 111) in 35 paediatric centres. FB was performed either in an operating theatre (15 centres), a dedicated bronchoscopy suite (6 centres) or an endoscopy suite shared with gastro-enterologists (7 centres). Other examinations were performed in areas dedicated to, or associated with intensive care. General anaesthesia was routinely used in 18 centres. The others used sedation including an equimolar mixture of oxygen and nitrous oxide in 14 centres. Ten centres performed less than 50 examinations, 12 between 51 and 100, 4 between 101 and 200 and 8 centres more than 200 in the year. Seventy two per cent of the children were less than 6 years old. The washing and disinfection procedures were manual in 20 centres and automatic in 15.

RESULTS

Three principal indications were reported: persistent wheezing, suspicion of a foreign body and ventilatory difficulties. Cough, desaturation and fever were the most frequently reported side effects.

CONCLUSIONS

This is the first survey in paediatric pulmonology in France. It shows a wide variation in the practice of fibreoptic bronchoscopy in children.

Nurse administered relative analgesia using high concentration nitrous oxide to facilitate minor procedures in children in an emergency department

AIMS

To describe the experience of using high concentration nitrous oxide (N(2)O) relative analgesia administered by nursing staff in children undergoing minor procedures in the emergency department (ED) and to demonstrate its safety.

METHOD

Data were collected over a 12 month period for all procedures in the ED performed under nurse administered N(2)O sedation. All children greater than 12 months of age requiring a minor procedure who had no contraindication to the use of N(2)O were considered for sedation by this method. The primary outcome measure was the incidence of a major complication namely respiratory distress or hypoxia during the procedure. Secondary outcome measures were minor complications and the maximum concentration of N(2)O used.

RESULTS

Data were collected for a total of 224 episodes of nurse administered N(2)O sedation over a 12 month period. In 73.2% of children no complications were recorded. One major complication was recorded (respiratory distress) and the most common minor complication was mask intolerance in 17%. The mean maximum concentration of N(2)O used was 60.2%.

CONCLUSIONS

N(2)O is a safe analgesic in children over the age of 1 year undergoing painful or stressful procedures in the ED. It may safely be administered in concentrations of up to 70% by nursing staff after appropriate training.

[Analgesia with oxygen-nitrous oxide mixture during percutaneous renal biopsy in children]

The efficacy of an inhaled equimolar mixture of nitrous oxide and oxygen (Entonox/MEOPA) to prevent procedural pain during renal percutaneous biopsies in children was assessed.

PATIENTS AND METHODS

One hundred and seven children who underwent 113 renal biopsies during a 17-month period were included in a prospective uncontrolled pediatric study. Efficacy was evaluated using patients' answers to a questionnaire and nurses' observations.

RESULTS

Pain was absent in 86.5% of the cases. Mild adverse events were noted in one-third of the procedures, and were always reversible within a few minutes when the inhalation stopped. Acceptability was good. The use of this gas is easy and safe provided a few precautions are observed.

CONCLUSION

Inhaled equimolar mixture of nitrous oxide and oxygen prevents procedural pain during renal percutaneous biopsies.