Analysis On The Application Of Nitrous Oxide In Colonoscopy And The Related Factors Affecting Its Comfort

BackgroundChina is country with its high incidence and mortality rate of colorectal cancer and the average of which is higher than that of the world and the developing country,and still shows the rising trend.In the composition of gender,the male is higher than female both in incidence and mortality rate.In the composition of age,the people between 45 and 85 years old is the high incidence rate group.In recent years the morbidity showed younger trend.For the precancerous lesions and most colorectal cancer,however,the treatment in the early stage shows a significantly better effect.Therefore the early screening and treatment is very important.Therefore the early screening and treatment is very important.Colonoscopy is one of the most common ways for colorectal screening,it helps with the early diagnosis and removal of colorectal related lesions,thus lower down the incidence and mortality rate of colorectal cancer.However in regular colonoscopy screening,people stay in clear mind during the whole procedure,having the negative mood of anxiety and fear for colonoscopy and feeling the pain and distention during the procedure,all of which make people cooperate badly and lower down the comfort during the procedure.Colonoscopy screening with intravenous anesthesia(propofol for example)solves problems above but causes some new such as significant pain associated with injection,requirement for professional anesthetist,side events of anesthesia and relatively higher amounts of examination fee,all of which limit its generation.So there is a great need searching for a safer sedation and analgesia way with more comfort and lowering down the examination fee.Nitrous oxide also known as"laughing gas" becomes a substitute of propofol for its relatively lower price,no injection pain,less adverse reaction and no need for professional anesthetist.And now nitrous oxide has been used in many clinical fields.Primary studies have showed that conscious sedation and ease pain through nitrous oxide inhalation is safe and effective in gastrointestinal endoscopy,but few focused on the factors affect the comfort.This study aimed at evaluating the comfort through the nitrous oxide inhalation during colonoscopy and analysing its factors then establishing a predicting model for better use of the conscious sedation and ease pain by nitrous oxide in colonoscopy.ObjectiveTo evaluate the comfort through the nitrous oxide inhalation during colonoscopy and analyse its factors for better use of the conscious sedation and ease pain by nitrous oxide in colonoscopyMethodsFrom October 2016 to July 2017 in gastrointestinal endoscopy center of our hospital,a total of 162 patients using 5 points MGCS(Modified Gloucester Comfort Scale)to rated comfort:scale 1 to 5(no discomfort to severe discomfort).Scores of 4 and 5 were considered to indicate significant discomfort.Data including age,gender,body mass index(BMI),history of excessive drinking,previous conventional colonoscopy experience,history of constipation,history of diarrhea,complaint of abdominal pain before colonoscopy,previous abdominal or pelvic surgery,mild anxiety,anxiety state were recorded before the examination to predict comfort using univariate analysis and multivariate logistic regression,then a comfort stratification model for predicting comfort was created.Results154 cases were included in the study at the end.According to MGCS the number of patients from scale 1 to 5 is 16?80?19?35?4,with 115(74.7%)rated comfort and 39(25.3%)rated discomfort.Univariate analysis showed older age(?60),mild anxiety,anxiety state were all associated with patient's comfort when operating the colonoscopy(P<0.05).Multivariate logistic regression indicated that older age(X1),mild anxiety(X2)these two variables as comfort factors(P<0.05).And the established model with the 2 variables was:P=eY/(1+eY),Y =-3.812+0.071×X1+1.205×X2,the best cut-off value determined by Yoden Index showed a sensitivity of 50.4%and a specificity of 89.7%for predicting comfort in colonoscopy.Conclusions1.Conscious sedation and ease pain through Nitrous oxide inhalation can reduce the discomfort during colonoscopy screening especially for patients over 60 years old and with anxiety.2.For those not so sensitive to the nitrous oxide inhalation(such as younger age)using different sedative or analgesic(such as propofol)based on the actual situation to reduce the discomfort might be a good option.