[Effect of high flow nasal catheter oxygen to prevent hypoxemia in endoscopic retrograde cholangiopancreatography surgery in aged].

Objective: To explore the effect of high-flow nasal catheter oxygen inhalation in preventing hypoxemia during endoscopic retrograde cholangiopancreatography (ERCP) surgery in elderly patients. Methods: From September 2021 to September 2022, 116 elderly patients (aged ≥ 70 years) who underwent elective ERCP in the Northern Theater General Hospital were prospectively selected, then divided into general nasal catheter oxygen inhalation group [group C, 31 males and 27 females, aged (79.8±6.4) years] and high-flow nasal catheter oxygen inhalation group [group H, 33 males and 25 females, aged (81.4±6.7) years], with 58 patients in each group. All patients were monitored for anesthesia by target-controlled infusion of propofol and remifentanil. The main outcome index was the incidence of intraoperative subclinical hypoxemia (90% ≤ SpO2 < 95%, duration >5 s), hypoxemia (75% < SpO2 < 90%, 5 s < duration ≤ 60 s) and severe hypoxemia (SpO2 < 75% or SpO2 < 90%, duration > 60 s). Secondary observation measures were SpO2 from T0 to T5 (T0, before anesthesia induction; T1, immediately after anesthesia induction; T2, endoscopic introduction; T3, duodenal papula intubation; T4, endoscopic withdrawal; T5, postoperative awakening), the arterial oxygen partial pressure (PaO2), carbon dioxide partial pressure (PaCO2) and pH at T0, 15 min after the induction and T5. Results: The incidence of intraoperative subclinical hypoxemia in group C and group H was 12.0% (7/58) and 3.4% (2/58) respectively, which showed no significant statistical difference (P=0.165) from each other. The incidence of intraoperative hypoxemia in group H was 8.6% (5/58), which was significantly lower than 31.0% (18/58) of group C (P=0.003). Neither group had intraoperative severe hypoxemia. SpO2 of group H were (98.2±0.9)%, (98.2±0.9)%, (97.8±1.7)% and (97.7±1.7)% at T1, T2, T3, T4, which were higher than (96.8±2.1)%, (96.4±3.0)%, (96.1±2.9)% and (96.4±3.4)% in group C (all P<0.05). PaO2 at 15 min after induction in group H was (240.5±46.7) mmHg (1 mmHg=0.133 kPa), which was higher than that of group C (170.6±33.4) mmHg (P<0.001). There was no statistically significant difference in pH and PaCO2 between the two groups of patients at each timepoint. Conclusion: High flow nasal catheter oxygen can effectively reduce the incidence of hypoxemia in ERCP in elderly patients.

Protective effects of remifentanil preconditioning on cerebral injury during pump-assisted coronary artery bypass graft.

The protective effects of remifentanil preconditioning on serum superoxide dismutase (SOD) and malondialdehyde (MDA) during pump-assisted coronary artery bypass graft (CABG) were investigated. Forty pump-assisted CABG patients were randomly divided into a remifentanil preconditioning group (R group) and a control group (C group, N = 10; normal saline). The R group was further divided into 3 sub-groups (R1, R2, and R3; N = 10 per group) according to the remifentanil dose (0.6, 1.2, and 1.8 µg·kg(-1)·min(-1), respectively). A venous blood sample was taken at anesthesia induction (T0), before cardiopulmonary bypass (CPB) (T1), CPB 30 min (T2), and after CPB (T3), and protein concentrations were measured. Patients were tested 24 h before and after the operation with the Mini-Mental State Examination (MMSE), and the difference was calculated. The MMSE score difference in the R3 group was lower than those of the other 3 groups (P < 0.05). At T2 and T3, the R3 group showed a significant decrease in S-100ß protein and MDA and an increase in SOD (P < 0.05) compared with the other groups, and S-100ß was negatively correlated with SOD activity (T2: r = -0.76, -0.80, P < 0.01; T3: r = -0.795, P < 0.01), and was positively correlated with MDA density (T2: r = 0.71, P < 0.01; T3: r = 0.71, P < 0.01). In conclusion, high-dosage remifentanil preconditioning played a protective role on brain damage, possibly through inhibition of the oxidative stress response.