Objective To investigate the effect of different lengths of unilateral nasal tube insertion on patient comfort. Methods A total of 99 patients who underwent cardiothoracic surgery in a hospital in Nanchong from December 2020 to January 2021 were selected as the study subjects.Subjects were intubated with an nasal tube at a length of 2

3

4

5

7

and 10 cm

respectively

and oxygen therapy was performed for 2 h（During oxygen therapy

an inquiry should be conducted to see whether the patient could tolerate it.If it was very intolerable

the nasal tube needed to be removed and the reasons for intolerance recorded）.Heart rate

blood pressure

and saturation were measured before insertion and before removal of the nasal tube.A self-made comfort score scale was used to assess the patient’s comfort before insertion and removal of the tube.Results There was no significant difference in heart rate

systolic blood pressure

and diastolic blood pressure before insertion and removal of the nasal tube（P>0.05）. The saturation and comfort scores of patients before insertion of nasal tube were higher than those before removal of nasal tube

and the differences were statistically significant（P<0.05）. There was no correlation between gender

age

saturation

heart rate

blood and comfort score before insertion of nasal tube and removal of nasal tube（P>0.05）. There was a negative correlation between the length of the nasal tube and comfort scores before insertion and removal of the oxygen tube（P<0.05）. There was no significant difference in patient comfort scores before and after the insertion of nasal tubes at 2 and 3 cm（P>0.05）. The patient comfort score was lower than that before insertion of the nasal tube after insertion of the nasal tube at 4

5

7

and 10 cm

and the differences were statistically significant（P<0.05）. No intolerance was observed after insertion of the nasal tube at 2 or 3 cm. The proportion of intolerance in patients after insertion of nasal tube at 10 cm was higher than that in patients after insertion of nasal tubes at 2

3

4

5

and 7 cm

and the differences were statistically significant（P<0.05）. Conclusion The insertion length of the nasal tube is negatively correlated with the patient’s comfort.When the insertion length of the nasal tube is 2-3 cm

the patient’s comfort is higher.It is recommended that clinical medical staff insert the nasal tube at the length of 2-3 cm into the nasal cavity without affecting the therapeutic effect when performing unilateral nasal tube oxygen therapy for postoperative awake patients

so as to improve the patient’s comfort.