Pain Management Needs In Postherpetic Neuralgia And The Effectiveness Of A Fixed Nitrous Oxide/Oxygen Mixture As An Analgesic For Patients With Postherpetic Neuralgia

Objective To understand the pain management needs of postherpetic neuralgia and explore the analgesic effect of a fixed nitrous oxide/oxygen mixture on postherpetic neuralgia.MethodsQualitative and quantitative methods were used in this study.1.In the qualitative study,10 patients with postherpetic neuralgia and 6 medical workers in the pain department of a third-grade class A hospital in western China were selected as the interviewees from January to April 2019,using the purposed sampling method,and semi-structured interviews were conducted.Colaizzi phenomenological analysis was used to analyze the interview data to understand the pain management needs of postherpetic neuralgia.2.In the quantitative study,a randomized controlled double-blind trial was used to evaluate the analgesic effect of a fixed nitrous oxide/oxygen mixture on postherpetic neuralgia after the ethical approval of medical research and the registration of clinical trials.Patients with postherpetic neuralgia who visited the pain department between June 2019 and October 2020 were enrolled and divided into an intervention group and a control group using a computer-generated random number table,with 21 patients in each group.The intervention group was given routine treatment+a fixed nitrous oxide/oxygen mixture inhalation,while the control group was given routine treatment+oxygen inhalation.The pain degree,heart rate,blood pressure,oxygen saturation,anxiety and adverse reactions of patients were observed and recorded 2min before intervention（T₀）,5min after the beginning of intervention（T₁）,15min after the beginning of intervention（T₂）,and 5min post intervention（T₃）,and the patients’satisfaction of the analgesic effect was explored.Results1.Qualitative research had extracted 7 themes and 13 sub-themes:（1）Four themes and nine sub-themes were identified from the patient interviews.Theme1:Incorrect cognition:（1）misunderstanding the cause of disease（2）lack of nutritional knowledge;Theme 2:Painful Struggle:（1）not wanting to live（2）try various analgesic methods（3）despair and helplessness;Theme 3:Interfering with normal life:（1）diet and sleep disorders（2）disrupting relationships and social activities（3）depression,anxiety,guilt（4）vicious circle;Theme 4:Desire for quick pain relief.（2）Three themes and four sub-themes were identified from the interviews with medical workers.Theme 1:PHN health education is not in place:（1）lack of health knowledge of PHN（2）unbalanced diet;Theme 2:Dilemmas in PHN management:（1）lack of psychological care（2）restricted analgesic measures;Theme 3:Multimodal analgesia.2.Results of a randomized controlled trial:Baseline data（age,gender,course of disease,pain site,pain score,and anxiety level）of 2 groups showed no statistical difference（P>0.05）and were comparable.The pain scores in the intervention group were significantly lower than those in the control group at T₁,T₂and T₃time points（P<0.01）.There was no statistical difference in the incidence of adverse reactions between 2 groups（P>0.05）.There were no statistically significant differences in heart rate,blood pressure and oxygen saturation between the intervention group and the control group（P>0.05）.The degree of satisfaction in the intervention group was higher than those in the control group,with statistical significances（P<0.01）.5min after the end of the experiment（T₃）,the anxiety degree of the intervention group was lower than that of the control group,the difference was statistically significant（P<0.01）.Conclusion1.PHN pain management is not ideal,and a safe,effective and rapid analgesic measure is urgently needed to relieve the pain of PHN patients2.A fixed nitrous oxide/oxygen mixture can safely and quickly relieve pain and anxiety in PHN patients with high patient satisfaction.