Objective To evaluate the effect of minimal tidal volume mechanical ventilation on the function of heart brain and lungs in patients undergoing flexible ureteroscopy.
Methods Seventy-four patients scheduled for ureteroscopic holmium laser lithotripsy under tracheal intubation anesthesia, 59 males and 15 females, aged 25-60 years, with a BMI 18-28 kg/m2, falling into ASA physical status Ⅰ or Ⅱ, were divided into 3 groups according to different ventilation methods randomly: conventional mechanical ventilation group (group C, n = 20), apena group (group A, n = 28), and minimal tidal volume mechanical ventilation group (group M, n = 26). The intraoperative ventilation mode of group C was used VT 6 ml/kg and RR 12 times/min. In group A, VT 6 ml/kg and RR 12 times/min were used, mechanical ventilation was suspended at the beginning of lithotripsy and resumed after the lithotripsy was finished, the longest maximum pause time was 5 min and the times of pause were determined according to the condition of lithotripsy. In group M, VT 6 ml/kg and RR 12 times/min were used, the minimal tidal volume mechanical ventilation mode was used when the lithotripsy started, then we used VT 3 ml/kg and RR 24 times/min, as well as SpO2 decreased to 95% as the limit of restoring normal mechanical ventilation. Blood samples were collected before anesthesia (T1) , before surgery (T2), before the start of lithotripsy (T3), after the completion of lithotripsy immediately (T4), and 30 min after extubation (T5) for blood gas analysis. pH, PaCO2 were recorded. Oxygenation index (OI), the arterial and internal jugular venous oxygen pressure difference (Pa-jvO2) , blood oxygen saturation difference (Sa-jvO2), and cerebral extraction rate of oxygen (CERO2) were calculated. Blood samples were collected from the vein for determination of S100β protein, myoglobin (MB), creatine kinase (CK)-MB, and troponin I and T at T1, T5, and 24 h after surgery (T6). The time of laser lithotripsy and the score of the mobility of stones from surgeon were recorded. The intraoperative adverse reactions were recorded.
Results Compared with group C, the value of PaCO2 in group A was significantly higher, while the value of pH and OI was significantly lower at T4 (P < 0.05). Compared with group A, the value of PaCO2 in group M was significantly lower, while the value of pH and OI was significantly higher at T4(P < 0.05). The time of laser lithotripsy was significantly shortened, and the surgeon was more satisfied with the condition of the lithotripsy (P<0.05) in group A and group M. There was no significant difference in CC16, rSO2, CERO2, Pa-jvO2, Sa-jvO2, S100β protein, MB, CK-MB, and troponin I and T among three groups at each time point. The incidence of adverse reaction indicators had no difference among three groups.
Conclusion The minimal tidal volume mechanical ventilation strategy can be safely and effectively applied to flexible ureteroscopy. |
