Nami Kakuta

Differential effects of propofol and isoflurane on glucose utilization and insulin secretion

AIMS Volatile anesthetics, such as isoflurane, reverse glucose-induced inhibition of pancreatic adenosine triphosphate-sensitive potassium (K(ATP)) channel activity, resulting in reduced insulin secretion and impaired glucose tolerance. No previous studies have investigated the effects of intravenous anesthetics, such as propofol, on pancreatic K(ATP) channels. We investigated the cellular mechanisms underlying the effects of isoflurane and propofol on pancreatic K(ATP) channels and insulin secretion. MAIN METHODS Intravenous glucose tolerance tests (IVGTT) were performed on male rabbits. Pancreatic islets were isolated from male rats and used for a perifusion study, measurement of intracellular ATP concentration ([ATP](i)), and patch clamp experiments. KEY FINDINGS Glucose stimulus significantly increased insulin secretion during propofol anesthesia, but not isoflurane anesthesia, in IVGTT study. In perifusion experiments, both islets exposed to propofol and control islets not exposed to anesthetic had a biphasic insulin secretory response to a high dose of glucose. However, isoflurane markedly inhibited glucose-induced insulin secretion. In a patch clamp study, the relationship between ATP concentration and channel activity could be fitted by the Hill equation with a half-maximal inhibition of 22.4, 15.8, and 218.8 μM in the absence of anesthetic, and with propofol, and isoflurane, respectively. [ATP](i) and single K(ATP) channel conductance did not differ in islets exposed to isoflurane or propofol. SIGNIFICANCE Our results indicate that isoflurane, but not propofol, decreases the ATP sensitivity of K(ATP) channels and impairs glucose-stimulated insulin release. These differential actions of isoflurane and propofol on ATP sensitivity may explain the differential effects of isoflurane and propofol on insulin release.

The effects of intravenous fosaprepitant and ondansetron for the prevention of postoperative nausea and vomiting in neurosurgery patients: a prospective, randomized, double-blinded study.

The incidence of postoperative nausea and vomiting (PONV) is 30–50% after surgery. PONV occurs frequently, especially after craniotomy. In this study, we investigated the preventive effects on PONV in a randomized study by comparing patients who had been administered fosaprepitant, a neurokinin-1 (NK1) receptor antagonist, or ondansetron intravenously. Sixty-four patients undergoing craniotomy were randomly allocated to receive fosaprepitant 150 mg i.v. (NK1 group, n = 32) or ondansetron 4 mg i.v. (ONS group, n = 32) before anesthesia. The incidence of vomiting was significantly less in the NK1 group, where 2 of 32 (6%) patients experienced vomiting compared to 16 of 32 (50%) patients in the ONS group during the first 24 and 48 hours following surgery. Additionally, the incidence of complete response (no vomiting and no rescue antiemetic use) was significantly higher in the NK1 group than in the ONS group, and was 66% versus 41%, respectively, during the first 24 hours, and 63% versus 38%, respectively, during the first 48 hours. In patients undergoing craniotomy, fosaprepitant is more effective than ondansetron in increasing the rate of complete response and decreasing the incidence of vomiting at 24 and 48 hours postoperatively.

The influence of glucose load on metabolism during minor surgery using remifentanil-induced anesthesia

During perioperative fasting, lipid metabolism gradually increases, resulting in free fatty acids (FFA) and/or ketone bodies. Suppression of surgical stress by remifentanil may allow the safe administration of glucose infusions, avoiding both hyperglycemia and ketogenesis. The effects of glucose infusion on glucose and lipid metabolism were therefore investigated in patients undergoing minor surgery with remifentanil anesthesia.

Effectiveness of using non‐invasive continuous arterial pressure monitoring with ClearSight in hemodynamic monitoring during living renal transplantation in a recipient:a case report

We investigated the effectiveness of the ClearSight system for hemodynamic management during kidney transplantation for a recipient. The recipient was to receive a kidney transplant from his mother under general anesthesia. We used continuous noninvasive finger-cuff-based monitoring of blood pressure, provided by the ClearSight system, and stroke volume variation to predict fluid responsiveness. We used of a balanced anesthetic technique and stringent monitoring standards to ensure a successful outcome for the patient. This case demonstrated that ClearSight has the potential to improve patient monitoring in hemodynamically stable patients who received kidney transplantation under general anesthesia. J. Med. Invest. 65:139-141, February, 2018.

Noninvasive continuous blood pressure monitoring by the ClearSight system during robot‐assisted laparoscopic radical prostatectomy

Robot-assisted laparoscopic radical prostatectomy (RALRP) is commonly performed in the surgical treatment of prostate cancer. However, the steep Trendelenburg position (25) and pneumoperitoneum required for this procedure can sometimes cause hemodynamic changes. Although blood pressure is traditionally monitored invasively during RALRP, the ClearSight system (BMEYE, Amsterdam, The Netherlands) enables a totally noninvasive and simple continuous blood pressure and cardiac output monitoring based on finger arterial pressure pulse contour analysis. We therefore investigated whether noninvasive continuous arterial blood pressure measurements using the ClearSight system were comparable to those obtained invasively in patients undergoing RALRP. Ten patients scheduled for RALRP with American Society of Anesthesiologists physical status I-II were included in this study. At each of the seven defined time points, noninvasive and invasive blood pressure measurements were documented and compared in each patient using Bland-Altman analysis. Although the blood pressure measured with the ClearSight system correlated with that measured invasively, a large difference between the values obtained by the two devices was noted. The ClearSight system was unable to detect blood pressure accurately during RALRP, suggesting that blood pressure monitoring using this device alone is not feasible in this small patient population. J. Med. Invest. 65:69-73, February, 2018.

The Efficacy of Programmed Intermittent Epidural Bolus for Postoperative Analgesia after Open Gynecological Surgery: A Randomized Double-Blinded Study

Background It is well known that the programmed intermittent epidural bolus (PIEB) technique effectively provides epidural anesthesia in labor. This randomized double-blind trial compared the postoperative analgesic efficacy of PIEB with that of continuous epidural infusion (CEI) in patients undergoing gynecological surgery under combined general-epidural anesthesia. Methods Patients undergoing open gynecological surgery under combined general-epidural anesthesia were randomized at a 1 : 1 ratio to receive PIEB or CEI. In the PIEB group, the pump delivered 4 mL ropivacaine 0.2% plus fentanyl 2 μg/mL every hour. In the CEI group, the pump delivered the same solution at a rate of 4 mL/h. In both groups, additional 4 mL boluses of ropivacaine 0.2% plus fentanyl 2 μg/mL were provided, when necessary, by patient-controlled epidural analgesia after surgery. The primary outcome was the total ropivacaine dose 40 hours after surgery. The secondary outcomes were the number of PCEA boluses and postoperative pain (evaluated on an 11-point numerical rating scale) 3, 24, and 48 hours after surgery. Results In total, 57 patients were randomized (n = 28 and 29 in the PIEB and CEI groups, resp.). The two groups differ significantly in terms of the total ropivacaine dose 40 hours after surgery (mean (standard deviation): 155.38 (4.55) versus 159.73 (7.87) mL, P = 0.016). Compared to the CEI group, the PIEB group had significantly lower numerical rating scale scores 3 hours (median [lower–upper quartiles]: 0 [0–0.5] versus 3 [0–5.5], P = 0.002), 24 hours (1 [0–2] versus 3 [1–4], P = 0.003), and 48 hours (1 [0–2] versus 2 [2–3.5], P = 0.002) after surgery. Conclusion PIEB was better than CEI in terms of providing postoperative analgesia after open gynecological surgery under combined general-epidural anesthesia.

A Comparison of Fosaprepitant and Ondansetron for Preventing Postoperative Nausea and Vomiting in Moderate to High Risk Patients: A Retrospective Database Analysis

Postoperative nausea and vomiting (PONV) occur in 30–50% of patients undergoing general anesthesia and in 70–80% of high PONV risk patients. In this study, we investigated the efficacy of fosaprepitant, a neurokinin-1 (NK1) receptor antagonist, compared to ondansetron, a selective 5-hydroxytryptamine type 3 (5-HT3) receptor antagonist, in moderate to high PONV risk patients from our previous randomized controlled trials. Patients (171 patients from 4 pooled studies) with the Apfel simplified score ≥ 2 and undergoing general anesthesia were randomly allocated to receive intravenous fosaprepitant 150 mg (NK1 group, n = 82) and intravenous ondansetron 4 mg (ONS group, n = 89) before induction of anesthesia. Incidence of vomiting was significantly lower in the NK1 group compared to the ONS group 0–2, 0–24, and 0–48 hours after surgery (2 versus 17%, 2 versus 28%, and 2 versus 29%, resp.). However, no significant differences in PONV, complete response, rescue antiemetic use, and nausea score were observed between groups 0–48 hours after surgery. In moderate to high PONV risk patients, fosaprepitant decreased the incidence of vomiting and was superior to ondansetron in preventing postoperative vomiting 0–48 hours after surgery.