Predictive Risk Factors of Cardiorespiratory Abnormality for Upper Gastrointestinal Endoscopy in Tibet

To explore the predictive factors of cardiorespiratory abnormality in nonsedated patients at high altitude (HA) during upper gastrointestinal endoscopy (UGIE). The pulse and saturated oxygen (SaO2) levels of 993 patients undergoing nonsedated UGIE in Tibet were monitored. Bivariate correlation and logistic regression were used to identify predictive risk factors for hypoxemia. The basal and minimum SaO2 levels during UGIE of the Tibetan group were significantly higher than those of the non-Tibetan group. The minimum SaO2 and maximum pulse in the HA transient residents groups were significantly higher than those in the HA usual residents groups. The incidences of hypoxemia and severe hypoxemia in the Tibetan groups were significantly lower than those of the non-Tibetan groups. Bivariate correlation and logistic regression showed that race, age (≥40 years), residence time in HA (