Correlation between Pet-CO2 and PaCO2 in morbidly obese patients during anesthesia for laparoscopic gastric bypass surgery / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the correlation between arterial partial pressure of CO2 (PaCO2) and end expiratory tidal partial pressure of CO2 (Pet-CO2) in morbidly obese patients during anesthesia for laparoscopic gastric bypass surgery.</p><p><b>METHODS</b>Forty morbidly obese patients with a body mass index (BMI) between 35 and 50 kg/m(2) underwent laparoscopic gastric bypass surgery under general anesthesia. PaCO2 and Pet-CO2 were measured after intubation and before induction of pneumoperitoneum (T0), at 30 min (T1), 60 min (T2), and 120 min (T3) during pneumoperitoneum, and at 30 min (T4) and 60 min (T5) after deflation.</p><p><b>RESULTS</b>At each time point of measurement, Pet-CO2 was lower than PaCO2 in all the patients. PaCO2 and Pet-CO2 were positively correlated before, during, and after pneumoperitoneum (P<0.05). At a moderate pressure of CO2 pneumoperitoneum (16 mmHg), the level of correlation between PaCO2 and Pet-CO2 at T1, T2, and T3 differed from that before and after post-pneumoperitoneum.</p><p><b>CONCLUSIONS</b>PaCO2 and Pet-CO2 are closely correlated during a moderate CO2 pneumoperitoneum in morbidly obese patients undergoing laparoscopic gastric bypass surgery.</p>

Stereological study of the placenta in patients receiving different vasopressors for hypotension during cesarean section / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the effects of dopamine and phenylephrine for treatment of hypotension during cesarean section under combined spinal epidural anesthesia (CSEA) on the stereology of the placenta.</p><p><b>METHODS</b>Forty puerperants undergoing cesarean section under CSEA were randomly divided into dopamine group and phenylephrine group. Ropivacaine (16 mg) was administered immediately after spinal anethesia. Blood pressure was maintained near the baseline by adjusting the drug infusion rate. Fetal blood gas, Apgar score, and placental villus microvascular stereological changes were observed during the operation.</p><p><b>RESULTS</b>The microvascular density was significantly lower in dopamine group than in phenylephrine group (P<0.05). Phenylephrine group showed significantly lower umbilical artery blood pH than dopamine group (P<0.05). The Apgar score and blood pressure were comparable between the two groups (P>0.05). Compared to the baseline, both of the two groups showed significantly lowered heart rate during the operation (P<0.01).</p><p><b>CONCLUSION</b>Dopamine is associated with the risk of fetal acidosis. Phenylephrine is helpful for preventing hypotension by increasing placental blood flow and improving oxygen supply to ensure maternal and fetal safety during cesarean section.</p>