Relation between fentanyl dose and patient state index during spinal anesthesia for elective cesarean section.

BACKGROUND: In spinal anesthesia for cesarean section, the addition of fentanyl to the local anesthetic has been reported to improve perioperative analgesia. However, there is only limited knowledge on sedative effects of the added fentanyl. We examined whether the patient state index® (PSI) can detect and present the light sedated level with patients undergoing cesarean section. FINDINGS: We measured respiratory rate (RR), SpO2, and PSI values. Between child delivery and the completion of the operation, the proportions of time with the PSI values <90 and 80 were calculated. RR <8 breaths/min or SpO2 <95 % was defined as respiratory depression. Respiratory depression was not observed in any patient. At fentanyl doses of 10, 15, and 20 µg, the proportions of time with the PSI <90 were 14.5 ± 20.8, 49.4 ± 35.3, and 71.1 ± 22.9 %, respectively (P < 0.01). There were significant differences between 10 and 15 µg (P < 0.05), and 10 and 20 µg (P < 0.01). Similarly, the proportions of time with the PSI values <80 were 0.5 ± 1.8, 21.1 ± 24.1, and 31.8 ± 32.2 %, respectively (P < 0.05). There was a significant difference between 10 and 20 µg (P < 0.05). CONCLUSIONS: The PSI values decreased in a dose-dependent manner with increasing dose of fentanyl, but no respiratory depression was observed. The PSI values decreased to less than 90, when fentanyl was administered more than 15 µg. Furthermore, the PSI values decreased to less than 80, when fentanyl was administered 20 µg.

[Anesthetic Management of a Patient Complicated with Marfan Syndrome and Suffering from Stanford Type A Aortic Dissection during Pregnancy].

We report a case of a 36-year-old woman at 34 weeks of gestation complicated with Marfan syndrome who underwent Bentall type aortic replacement surgery due to Stanford type A aortic dissection after undergoing caesarean section. Since this patient exhibited severe hypotension before coming to the operating room, it was very difficult to determine whether the cardiac surgery or caesarean section should be performed first. In this case, the caesarean section was performed first, followed by Bentall's surgery. Although intra-aortic balloon pumping and percutaneous cardiopulmonary support were required after weaning from the cardiopulmonary bypass, she was discharged on post-operative day (POD) 40 and the baby was discharged on POD 60, without signs of cerebral palsy. Unfortunately, this patient died on POD 57, due to heart failure. We discuss how to determine the priority of surgeries for patients who require emergency surgery for cardiovascular disease during pregnancy.

[Changes in Electrolytic Concentration Resulting from Perioperative Amino Acid Fluid Administration].

BACKGROUND: Amino acid infusion is frequently selected to avoid hypothermia during surgery. However, changes in electrolytic concentration resulting from its use are unclear. The aim of this study was to identify the effect of amino acid on body temperature and changes in electrolytic concentrations. METHODS: Thirty women undergoing breast cancer surgery under general anesthesia were divided into the following three groups: no amino acid administration, low-dose administration (2 ml x kg(-1) x hr(-1)), and high-dose administration (4 ml x kg(-1) x hr(-1)). Esophageal temperature was recorded every ten minutes and arterial blood samples were obtained before and after surgery. Body temperatures at each time point and arterial blood gas data, including blood gases, electrodes, serum glucose, and hematocrit were compared between the three groups. RESULTS: Body temperature started to increase significantly 40 minutes after starting general anesthesia in the high-dose group, 90 minutes after starting general anesthesia in the low-dose group compared with the no amino acid group. Body temperature was maintained until surgery was completed. The concentration of sodium ion decreased significantly (2.4 mmol x l(-1)) in the high-dose group compared with the other two groups. The concentration of other electrolytes, including potassium, chloride, and calcium, did not change significantly. CONCLUSIONS: Perioperative amino acid administration was effective in maintaining a stable body temperature during surgery under general anesthesia. However, sodium ion concentration might decrease after amino acid administration of 4 ml x kg(-1) x hr(-1) or greater.