By comparing the sedative effects of three anesthetisa methods of propofol on painless gastroscopy in morbidly obese patients to explore the optimal administration method of propofol.

90 patients with painless gastroscopy in the People's Hospital of Xinjiang Uygur Autonomous Region, aged 18 to 50 years, with BMI over 35 kg/m², and ASA class I to II. They were randomly divided into three groups according the digital table method, with 30 patients in each group. At first, all the three groups of patients were given 0.1 μg/kg Sufentanil; in group A, 2 mg/kg propofol was injected after 2 minutes. In the group B, 1mg/kg propofol was given during at the same time as sufentanil, and the addition of 1 mg/kg propofol after 2min. In the group C, propofol was injected to maintain the plasma concentration at Cpt 2.5 μg/mL by TCI during giving sufentanil. All three groups were inserted nasopharyngeal airway after the patient fell asleep and the reflexes of the eyelashes disappeared. The anesthesiologist lifted the patient's lower jaw and operation began after patients breathed smoothly. If there is obvious body movement during operation, additional 0.5 mg/kg propofol would be added to enhance and maintain anesthesia. The heart rate (HR) of the three groups before the induction of anesthesia (T₀), after the induction of anesthesia (T₁), and at the time of the blink (T₂) were recorded. We observed the numbers of coughing, significant respiratory depression and stopping operations; the Ramsay sedation score, time to start operation; time of opening their eyes, recovering orientation and recovering cognition, and propofol dosage (mg/kg).

There was a statistically significant difference in HR between T₁ and T₀ in group A and group C (P<0.05), but there was no significant difference in HR fluctuations in group B (P>0.05). The incidence of respiratory depression was significantly lower in group B than in group A and C (P<0.05). Compared with group B and C, the incidence of cough and cessation during operation was significantly higher in group A (P<0.05). Compared with group B and C, the Ramsay sedation score was significantly lower in group A (P<0.05). The time of starting operation, opening eyes, recovering orientation and cognition in group B were significantly shorter than those of group A and group C (P<0.05). Compared with group A and C, the dosage of group B was significantly reduced (P<0.05).

The best mode of anesthesia for painless gastroscopy in obese patients is drug administration in divided doses.