CARDIOVASCULAR TOLERANCE AND AUTONOMIC NERVOUS RESPONSES IN UNSEDATED UPPER GASTROINTESTINAL SMALL-CALIBER ENDOSCOPY: A COMPARISON BETWEEN TRANSNASAL AND PERORAL PROCEDURES WITH NEWLY DEVELOPED MOUTHPIECE

Background: Transnasal esophagogastroduodenoscopy (EGD) with small‐caliber endoscopy appears to be less stressful to the cardiovascular system and has good patient tolerance. ENDO LEADER, a newly developed mouthpiece for peroral EGD with small‐caliber endoscopy, is expected to reduce patient stress. We compared the patient acceptance, cardiovascular tolerance and autonomic nervous responses between transnasal EGD and peroral EGD with ENDO LEADER. Patients and Methods: A total of 130 patients (transnasal group, 77; peroral group, 53) were enrolled. Pulse rate (P), blood pressure (BP), and peripheral blood oxygen saturation (SpO2) were monitored. Acceptance of EGD was also assessed. Autonomic nervous responses were evaluated through analysis of heart rate variability using amplitude of the high‐frequency component (HF) and low‐frequency‐to‐high‐frequency power ratio (LF/HF) as indices of cardiac vagal activity and sympathetic activity, respectively. Results: Analysis of patient acceptance showed no differences between the two groups, except with regard to nasal pain. Increases in BP and P between before and during EGD examination were significantly higher in the peroral group. Although throat pain and overall tolerance scores were significantly correlated with ΔBP and ΔP, no correlations with nasal pain score were noted. Heart rate variability analysis revealed that heart rate increased significantly in the peroral group, but there were no differences in ΔHF or ΔLF/HF between the two groups. Conclusions: Patient acceptance was not significantly different between the transnasal and peroral with ENDO LEADER groups; however, transnasal EGD appears to be less stressful to the sympathetic nervous system, leading to smaller elevations in BP, P and heart rate.