Intensive insulin therapy during cardiovascular surgery

Recent evidence in the fields of surgery, emergency and critical care medicine indicates that strict glycemic control results in lower mortality. Hyperglycemia occurs frequently in patients with and without diabetes during cardiovascular surgery, especially during cardiopulmonary bypass. However, strict glucose control is difficult to achieve during cardiovascular procedures. To establish effective intensive insulin therapy during cardiovascular surgery, we conduct continuous blood glucose monitoring and employ automatic control by using an artificial endocrine pancreas (the STGR-22, Nikkiso, Tokyo, Japan). In this review, we will outline the present status and problems of conventional glycemic control for perioperative cardiovascular surgery and introduce the new perioperative blood glucose management method that we are testing now. We will also discuss the importance of perioperative glycemic control for cardiovascular surgery as well as future prospects

Cardioprotective effects of hyperkalemia during simulated ischemia/reperfusion in neonatal rat cardiomyocytes : Preservation of Na+/K+-ATPase activity

Background : Hyperkalemia has multimodal effects on myocardial protection during ischemia/reperfusion. The preservation of Na+/K+-ATPase activity induced by hyperkalemia may have critical impact on myocardial protection. Methods : To elucidate the roles of hyperkalemia (16 mM) and Na+/K+-ATPase inhibition (100 μMouabain) inmyocardial protection during simulated ischemia (5 mM NaCN and 5.5 mM 2-deoxyglucose)/ reperfusion, we measured loss of membrane integrity and bleb formation using a vital dye calcein AM in cultured neonatal rat cardiomyocytes. The control perfusate was switched to treatment solution for 15 min, followed by reperfusion for 30 min. In a second set of experiments, myocardial excitability and diastolic intracellular calcium ion concentration ([Ca2+]i) were measured during a 45-min treatment using a calcium-sensitive fluorescent dye fluo-4 AM. Results : Simulated ischemia/reperfusion under ouabain treatment induced loss of membrane integrity, which was suppressed by hyperkalemia. Simulated ischemia/reperfusion induced bleb formation, which was accelerated by ouabain. Hyperkalemia delayed and inhibited the increase in diastolic [Ca2+]i induced by simulated ischemia. Furthermore, hyperkalemia almost completely inhibited the effects of ouabain on the diastolic [Ca2+]i during ischemia. Conclusions : These results suggest that hyperkalemia during ischemia is cardioprotective against ischemia/reperfusion insults and that hyperkalemia inhibits the effects of ouabain during ischemia

Non-cardiac surgery applications of extracorporeal circulation

Although the efficacy of extracorporeal circulation (ECC) is well established for open-heart surgery, application of ECC in other surgical areas has not been given much attention. Advances in the related surgical technique and anesthetic management combined with refinements in the ECC procedure itself have encouraged several institutions to use ECC for complex non-cardiac surgeries. ECC is beginning to be used for circulatory support or tissue oxygenation during surgery on the lung, brain, liver, and kidney as well as in emergency situations. With ECC, difficult and complex surgeries can be performed more safely, and the success rate of certain surgeries has been positively affected. It is important that the surgeon, anesthesiologist, and perfusionist are trained in non-cardiac surgery applications of ECC. Thus, we review here non-cardiac uses that have emerged and summarize the related procedures

Minute distance obtained from pulmonary venous flow velocity using transesophageal pulsed Doppler echocardiography is related to cardiac output during cardiovascular surgery

Purpose. We studied the relationship between minute distance calculated from pulmonary venous flow (PVF) velocity tracing and cardiac output (CO)measured with thermodilution method in patients undergoing cardiovascular surgery. Methods. In 32 patients undergoing cardiovascular surgery, simultaneous measurements of hemodynamics including CO and transesophageal pulsed Doppler signals of PVF velocity were performed before and after surgical repair. Minute distance was calculated as the product of the heart rate and the sum of time-velocity integrals of PVF. Results. The minute distance after surgical intervention increased from 1121 ± 347 cm・sec-1to 1764 ± 538 cm・sec-1 (plt0.001 mean ± SD), while CO increased after surgical intervention from3.5 ± 0.9 L・min-1 to 5.3 ± 1.1 L・min-1. Simple linear regression analysis showed that minute distance was related with CO before and after surgical intervention (r=0.81 and r=0.76, respectively). The changes in minute distance were also related with those in CO (r=0.80). Conclusion. The present study demonstrated that minute distance obtained from the pulsed Doppler tracings of PVF velocity was related with CO during cardiovascular surgery in adults. These results suggest that the changes in CO could be estimated from minute distance in pulmonary vein

A case where rocuronium was unable to achieve neuromuscular block immediately after sugammadex administration

We present a case where immediatemuscle relaxation was needed following sugammadex administration. A 72 year-old female underwent surgery for a cerebral artery aneurysm. Upon conclusion of the operation sugammadex (9.3 mg/kg) was administered and the patient was noted to have left hemiplegia. Rocuronium (1.2 mg/kg 2 doses) was given in order to gain neuromuscular block approximately 25 minutes after sugammadex had been injected. Although TOF monitoring was not utilized in this case and assessing residual muscular block was difficult, spontaneous respirations continued and breathing had to be controlled with sevoflurane and remifentanil. Sugammadex is a potent reversal agent for rocuronium-induced neuromuscular block, however, certain situations require immediate neuromuscular blockade following sugammadex. In this case, rocuronium was unable to induce neuromuscular blockade immediately after sugammadex and that higher concentrations were necessary in addition to intravenous analgesics and inhaled anesthetics

Effects of a novel method of anesthesia combining propofol and volatile anesthesia on the incidence of postoperative nausea and vomiting in patients undergoing laparoscopic gynecological surgery

AbstractBackgroundWe investigated the effects of a novel method of anesthesia combining propofol and volatile anesthesia on the incidence of postoperative nausea and vomiting in patients undergoing laparoscopic gynecological surgery.MethodsPatients were randomly divided into three groups: those maintained with sevoflurane (Group S, n=42), propofol (Group P, n=42), or combined propofol and sevoflurane (Group PS, n=42). We assessed complete response (no postoperative nausea and vomiting and no rescue antiemetic use), incidence of nausea and vomiting, nausea severity score, vomiting frequency, rescue antiemetic use, and postoperative pain at 2 and 24h after surgery.ResultsThe number of patients who exhibited a complete response was greater in Groups P and PS than in Group S at 0–2h (74%, 76% and 43%, respectively, p=0.001) and 0–24h (71%, 76% and 38%, respectively, p<0.0005). The incidence of nausea at 0–2h (Group S=57%, Group P=26% and Group PS=21%, p=0.001) and 0–24h (Group S=62%, Group P=29% and Group PS=21%, p<0.0005) was also significantly different among groups. However, there were no significant differences among groups in the incidence or frequency of vomiting or rescue antiemetic use at 0–24h.ConclusionCombined propofol and volatile anesthesia during laparoscopic gynecological surgery effectively decreases the incidence of postoperative nausea. We term this novel method of anesthesia “combined intravenous-volatile anesthesia (CIVA)”

Usefulness of continuous blood glucose monitoring and control for patients undergoing liver transplantation

Background : The purpose of this study was to evaluate the usefulness of the closed-loop system (STG-22 ; Nikkiso, Tokyo, Japan), a type of artificial endocrine pancreas for the continuous monitoring and control of intraoperative blood glucose in patients undergoing liver transplantation. Methods : Sixteen patients undergoing livingdonor liver transplantation were enrolled in this study. Glucose levels were controlled with either a manual injection of insulin based on a commonly used sliding scale (manual insulin group, n=8) or a programmed infusion of insulin determined by the control algorithm of the artificial endocrine pancreas (programmed insulin group, n=8). The target glucose level range was set at 80-150 mg/dl. Results : The mean and SD of blood glucose concentration during surgery (Glu-Ave and Glu-SD, respectively) for the programmed insulin group were lower than for the manual insulin group. The coefficient of variability (Glu-CV=Glu-SD×100 /Glu-Ave) for the programmed insulin group was also lower than for the manual insulin group (20.1±4.9% vs. 26.9±6.1% ; mean±SD). No hypoglycemia was detected in either group. Conclusion : The STG-22 closed-loop system is effective for maintaining strict blood glucose control during liver transplantation with minimal variability in blood glucose concentration

Effects of ketamine on nicorandil induced ATP-sensitive potassium channel activity in cell line derived from rat aortic smooth muscle

Purpose : Nicorandil opens adenosine triphosphate-sensitive potassium (KATP) channels in the cardiovascular system and is being increasingly used for the treatment of angina pectoris. In the present study, we tested whether intravenous anesthetic agent ketamine affected nicorandil-induced native vascular KATP channel activation. Methods : We used excised inside-out patch clamp configurations to investigate the direct effects of ketamine racemate and S-(+)-ketamine on the activities of KATP channels in cultured rat aortic smooth muscle cells. Furthermore, we also investigated whether intracellular MgADP could modulate ketamine inhibition. Results : Nicorandil significantly activated KATP channel activity, whereas this channel activity was completely blocked by glibenclamide, a specific KATP channel blocker. Ketamine racemate inhibited the nicorandil induced KATP channel activity (IC50=34 1M, n=14), but S-(+)-ketamine was less potent than ketamine racemate in blocking nicorandil induced KATP channel activities (IC50=226 7M, n=10). Application of MgADP to the intracellular side of the channel was able to decrease the inhibitory potency of ketamine racemate on nicorandil induced KATP channel activities. Conclusions : Our results indicate that ketamine inhibits nicorandil induced KATP channel activities in a dose dependent and stereoselective manner. Furthermore, increase of intracellularMgADP attenuates the inhibitory potency of ketamine racemate