Comparative Study Of Monitoring End-expiratory CO₂ Through Mouth And Nose In Painless Gastroscopy

ObjectiveThis topic infers the patient’s respiratory circuit by collecting the PETCO2 values generated by the patient’s mouth and nose during painless gastroscopy,and based on the location and value of PETCO2 production.It is helpful for early detection of patient ventilation problems in clinical work,timely relief of respiratory depression,improvement of patient safety,and providing reference for patient oxygen supply（nasal or oral）methods.MethodThis study was a clinical observational study conducted on patients scheduled for propofol non-tracheal intubation general anesthesia during gastroscopy.The study population consisted of ASA class I-II patients aged 18-60 years.The study subjects were divided into two groups according to the method of monitoring end-tidal CO₂:the nasal group（Group A,control group）and the oral group（Group B,experimental group）.The P_ETCO₂changes in the two groups were observed during the operation,with P<0.05,indicating statistical significance.Observations1.Main observation indicators:after entering the room（T0）,1 minute after anesthesia induction（T1）,2 minutes after anesthesia induction（T2）,and 3 minutes after anesthesia induction（T3）P_ETCO₂value.2.Secondary observation indicators:heart rate,respiratory rate（electrocardiogram impedance method）,and SpO₂value,at each time point.Results1.There was no significant difference in heart rate,respiratory rate,and SpO₂between the two groups at each time point from the beginning of anesthesia to the end of the operation;2.Within-group comparison showed that the heart rate at each time point after anesthesia induction showed a decreasing trend,with statistical significance（P<0.05）;3.In Group A,the P_ETCO₂levels at T1,T2,and T3 after anesthesia induction were lower than those at T0,with statistical significance（P<0.05）;4.In Group B,the P_ETCO₂levels at T1,T2,and T3 after anesthesia induction were lower than those at T0,with statistical significance（P<0.05）;5.Inter-group comparison showed that the oral PETCO2 values at T1,T2,and T3 were higher than those in the nasal route group,and the difference was statistically significant（P<0.05）.ConclusionDuring propofol anesthesia-induced painless gastroscopy,the oral PETCO2value was higher than the nasal route PETCO2 value,indicating that most patients breathe through their mouths.This study provides a theoretical basis for selecting a more optimal oxygen administration route for painless diagnosis and treatment of patients.Furthermore,PETCO2 monitoring can detect respiratory depression in patients in real-time,allowing timely improvement of patient ventilation and reducing anesthesia risks before SpO2 decreases.