Objective To investigate the effects of resuscitation with limited fluid on rabbits with uncon-trolled hemordaagic shock. Method Uncontrolled hemorrhagic shock was produced in 40 rabbits. When the mean arterial pressure dropped to 40 manI-Ig and maintained for 30 minutes, resuscitation was initiated with Ringer solu-tion infusion into rabbits in large volume for group N3 (125 mL/kg) ,moderate volume for group N2 (92 mL/kg) and small amount for group N1 (57 mL/kg), and a drop of fluid was not given to rabbits of group N4. Besides, rob-bits of group N5 were controls without shock. MAP, fatality, volume of blood loss, SOD and Her were observed for 120 minutes or until death. Data were analyzed using SNK-q test and rank test. Results MAP, SOD and Het were higher, and fatality and blood loss were lower in group N5 than those in groups N1, N2,and N3 (P<0.01 ). MAP,fatality,blood loss and Het of group N4 were worse than those of groups N1,N2 and N3 (P<0.01). The blood loss and fatality in group N3 were significantly higher than those in groups N1 and N2 (P<0.01 ). SOD of kidney in group N3 was significantly lower than that in group N1 and N2(P<0.01). As the volume of fluid in-creased during resuscitation, Het of all animals was gradually becoming lower. As MAPS in groups N2, N3 and N4 were gradually becoming lower and lower, death increased. Conclusions Limited fluid resuscitation (57～92mL/kg) should be recommended to the therapeutic strategy for uncontrolled hemorrhagic shock.

Objective To determine the optimal pressure for facemask ventilation during induction of general anesthesia by real-time ultrasonographic measurement of antral cross-sectional area (CSA) in adult patients.Methods Sixty American Society of Anesthesiologists physical status Ⅰ or Ⅱ patients,aged 18-60 yr,with body mass index of 20-25 kg/m2,scheduled for elective operation under general anesthesia,were divided into 5 groups (n=12 each) using a random number table:P10 group,P13 group,P16 group,P19 group and P22 group.After induction of anesthesia,an oropharyngeal airway was inserted,and the patients were ventilated for a 2-min period in a pressure-controlled mode using the two-handed mask ventilation technique.The pressure for facemask ventilation was 10,13,16,19 and 22 cmH2O in P10,P13,P16,P19 and P22 groups,respectively.The antral CSA was measured using real-time ultrasonography before and after facemask ventilation.Respiratory parameters were recorded.Results Compared with group P1O,the number of patients in whom CSA＜340 mm2 after facemask ventilation was significantly decreased in P16,P19 and P22 groups,and the number of patients in whom the tidal volume ≥ 6 ml/kg was increased in P13,P16,P19 and P22 groups (P＜ 0.01).The number of patients in whom optimnal pressure for facemask ventilation was achieved was 2,10,6,4 and 1 in P10,P13,P16,P19 and P22 groups,respectively,with the most cases in group P13 (P ＜ 0.01).Conclusion The optimal pressure is 13 emH2O for facemask ventilation during induction of general anesthesia when determined by realtime ultrasonographic measurement of antral CSA,and it can ensure adequate oxygen supply and reduce gastric insufflation in adult patients.