Intraoperative Remifentanil Use Reduces Atrial Fibrillation After Coronary Artery Bypass Surgery.

Objectives: Atrial fibrillation after coronary artery bypass grafting is a relatively well known complication that has been observed for a long time. Though the management and drugs in the perioperative period have changed, their impact on the generation of postoperative atrial fibrillation remains unclear. Therefore, we investigated various perioperative management methods and the occurrence of postoperative atrial fibrillation. Methods: The patients underwent off-pump coronary artery bypass grafting between January 2010 and October 2019. The study was a retrospective observational study, and we investigated the incidence of atrial fibrillation during all 5 postoperative days. Patient factors included age, sex, height, and weight, preoperative factors included oral statin, HbA1c, left ventricular ejection fraction, and left atrial diameter; intraoperative factors included operation time, remifentanil use, beta-blocker use, magnesium-containing infusions use, in-out balance, and number of vascular anastomoses. Results: Postoperative atrial fibrillation was recognized in 81 out of 276 cases. There were significant differences between the two groups in terms of age, left atrial diameter, and intraoperative remifentanil use. A logistic regression analysis presented the effects of age (OR 1.045, 95% CI 1.015-1.076, P < 0.01), preoperative left atrial diameter (OR 1.072, 95% CI 1.023-1.124, P < 0.01), and intraoperative remifentanil use (OR 0.492, 95% CI 0.284-0.852, P = 0.011) on postoperative atrial fibrillation. Conclusions: Operative time did not affect postoperative atrial fibrillation. Age and left atrial diameter had previously been shown to affect postoperative atrial fibrillation, and our results were similar. This study showed that the use of remifentanil reduced the incidence of postoperative atrial fibrillation. On the other hand, no other factors were found to have an effect.

Severe Calcification of Femoral Arteries Causes Tourniquet Failure Accompanied by Massive Bleeding.

Tourniquet failure is attributed to inadequate tourniquet pressure, inadequate exsanguination, failure to compress medullary vessels within the bone, and incompressible calcified arteries. We herein report a case of massive bleeding using a properly functioning tourniquet in a patient who had bilateral calcified femoral arteries. When incompressible calcified arteries are present, the inflated tourniquet cuff fails to adequately compress the underlying artery, yet acts as an efficient venous tourniquet, which leads to an increase in bleeding. It is therefore critical to preoperatively confirm the effectiveness of the tourniquet in arterial occlusion in patients with severe arterial calcification.

Propofol, an Anesthetic Agent, Inhibits HCN Channels through the Allosteric Modulation of the cAMP-Dependent Gating Mechanism.

Propofol is a broadly used intravenous anesthetic agent that can cause cardiovascular effects, including bradycardia and asystole. A possible mechanism for these effects is slowing cardiac pacemaker activity due to inhibition of the hyperpolarization-activated, cyclic nucleotide-gated (HCN) channels. However, it remains unclear how propofol affects the allosteric nature of the voltage- and cAMP-dependent gating mechanism in HCN channels. To address this aim, we investigated the effect of propofol on HCN channels (HCN4 and HCN2) in heterologous expression systems using a whole-cell patch clamp technique. The extracellular application of propofol substantially suppressed the maximum current at clinical concentrations. This was accompanied by a hyperpolarizing shift in the voltage dependence of channel opening. These effects were significantly attenuated by intracellular loading of cAMP, even after considering the current modification by cAMP in opposite directions. The differential degree of propofol effects in the presence and absence of cAMP was rationalized by an allosteric gating model for HCN channels, where we assumed that propofol affects allosteric couplings between the pore, voltage-sensor, and cyclic nucleotide-binding domain (CNBD). The model predicted that propofol enhanced autoinhibition of pore opening by unliganded CNBD, which was relieved by the activation of CNBD by cAMP. Taken together, these findings reveal that propofol acts as an allosteric modulator of cAMP-dependent gating in HCN channels, which may help us to better understand the clinical action of this anesthetic drug.

Mortality at 180-days is affected by serum haptoglobin levels in septic patients with high magnitude serum high mobility group box-1 levels.

AIM: High mobility group box-1 (HMGB1) is a lethal mediator of sepsis that binds to haptoglobin (Hp) and is associated with its prognosis. We investigated the effect of the combination of HMGB1 and Hp on sepsis prognosis. METHODS: This single-center, retrospective study registered 78 patients with sepsis according to Sepsis-3 criteria on day 1 of diagnosis from July 2016 to November 2018. We divided the patients into four groups according to the serum concentration of 6.2 ng/mL HMGB1 and the median value of Hp. The 180-day mortality rates and cytokine concentrations of the low and high HMGB1 groups were compared. RESULTS: There was no difference in the 180-day mortality rate between the low Hp group and the high Hp group in the low HMGB1 group (P = 0.691). In the high HMGB1 group, a statistically significant difference was found between the low Hp group and the high Hp group (P = 0.002). In the high HMGB1 group, high Hp was associated with a better prognosis in univariate analysis (odds ratio, 0.131; 95% confidence interval [CI], 0.027-0.629; P = 0.011), and multivariate analysis (adjusted odds ratio, 0.086; 95% CI, 0.013-0.582; P = 0.009). In addition, in the high HMGB1 group, interleukin-8 levels were significantly higher in the low Hp group than in the high Hp group (P = 0.004). CONCLUSION: Patients with sepsis-induced high serum HMGB1 levels and low serum Hp levels could have a poor long-term prognosis.

Postoperative analgesic effect of ultrasound-guided rectus sheath block and local anesthetic infiltration after laparoscopic cholecystectomy: Results of a prospective randomized controlled trial.

INTRODUCTION: Even if laparoscopic cholecystectomy (LC) has lower invasiveness through small incisions compared with laparotomy, postoperative pain control is important. METHODS: This prospective, randomized, single-blinded, interventional, single-center study was conducted from December 2016 to March 2018 at the Shiga University of Medical Science Hospital in Japan. Enrolled patients were assigned to either a rectus sheath block (RSB) group or an infiltrative local anesthesia (LA) group. After LC, the RSB group received bilateral RSB with 10 mL of 0.375% ropivacaine and the LA group received subcutaneous and fascial injection with 10 mL of 0.75% ropivacaine at the umbilical wound. The primary endpoint was a visual analog scale (VAS) score on postoperative day (POD) 1. RESULTS: This study enrolled 62 patients (RSB group = 31, LA group = 31). On POD1, the mean VAS scores were 36.4 ± 18.9 and 29.4 ± 15.4 in the RSB group and LA groups, respectively, showing that the LA group tended to describe lesser postoperative pain than the RSB group (P = 0.062). CONCLUSIONS: VAS scores on POD1 were not different between the groups. LC patients might obtain postoperative pain control via long-acting local analgesia.

Utility of the FloTrac™ Sensor for Anesthetic Management of Laparoscopic Surgery in a Patient After Pneumonectomy: A Case Report and Literature Review.

BACKGROUND Pneumonectomy is associated with various anatomical changes and potential complications involving the respiratory and cardiovascular systems. How laparoscopic surgery affects cardiorespiratory status in postpneumonectomy patients is yet to be ascertained. Here, we describe the use of the FloTrac™ sensor for the anesthetic management of laparoscopic adrenalectomy in a postpneumonectomy patient. CASE REPORT A 35-year-old woman underwent an extended hysterectomy and right pneumonectomy for retroperitoneal angiosarcoma and lung metastases, respectively. The metastasis was found in her left adrenal gland; therefore, laparoscopic adrenalectomy was scheduled. Spirometry demonstrated the following: forced vital capacity (FVC), 1.90 L (55.6% of predicted value); vital capacity, 53.6%; forced expiratory volume (FEV1), 1.38 L (47.3% of predicted value); and FEV1/FVC, 72.4%. The heart and mediastinal structures had shifted into the right hemithorax. Hugh-Jones classification was grade 2. The induction of general anesthesia was planned. The patient was orotracheally intubated and managed with the pressure control ventilation-volume guaranteed mode of ventilation, targeting an expired tidal volume of 6-7 ml/kg, without using PEEP. We evaluated cardiac output (CO), cardiac index (CI), stroke volume (SV), and stroke volume variation (SVV) using a FloTrac™ sensor. After the establishment of pneumoperitoneum, SVV increased. CO and SV decreased slightly; however, the patient's hemodynamic status was stable. After surgery, we extubated the patient in the operating room; she demonstrated good progress and was discharged home on postoperative day 5. CONCLUSIONS We found changes in the values of SVV after pneumoperitoneum in a postpneumonectomy patient. The FloTrac™ sensor may be a minimally invasive and promising monitor for detecting hemodynamic changes associated with laparoscopic surgery in postpneumonectomy patients.

Perioperative tight glycemic control using artificial pancreas decreases infectious complications via suppression of inflammatory cytokines in patients who underwent pancreaticoduodenectomy: A prospective, non-randomized clinical trial.

BACKGROUND: We sought to investigate the efficacy of perioperative tight glycemic control (TGC) in reducing of postoperative infectious complications (POICs) and study its impact on early inflammatory mediators in patients who underwent pancreaticoduodenectomy. METHODS: In this non-randomized trial, the artificial pancreas (AP) group received TGC (target glucose range of 80-110 mg/dL; n = 14), while the control group received conventional glycemic control (range of 80-180 mg/dL; n = 15). The primary endpoint was POICs. RESULTS: The AP group had a markedly decreased POIC rate (28.6% vs. 73.3%; P = 0.027), mean glycemic variability (13.5 ± 3.5% vs. 16.4 ± 5.9%; P = 0.038), and plasma interleukin-6 level (26.3 ± 33.8 vs 98.3 ± 89.1 pg/ml; P = 0.036) compared to the control group, but insulin dosage (27.0 ± 13.4 vs. 10.2 ± 16.2 U; P = 0.002) and the adiponectin ratio (i.e., postoperative/preoperative adiponectin; 0.8 ± 0.2 vs. 0.6 ± 0.3; P = 0.021) were markedly higher in the AP group. CONCLUSIONS: Among patients undergoing PD with impaired glucose tolerance, AP facilitated strict glycemic control and resulted in a reduction of anti-inflammatory mediators and POICs. SUMMARY: Perioperative hyperglycemia increases postoperative infectious complications; however, tight glycemic control using artificial pancreas can reduce them via a dual effect. Artificial pancreas facilitates strict and safe glycemic control while reducing anti-inflammatory mediators, including adiponectin, following pancreaticoduodenectomy.

[Two Cases of Convulsive Seizures after Cardiac Surgery Suspiciously Caused by Tranexamic Acid Administration in Patients on Chronic Hemodialysis].

Tranexamic acid (TA), an antifibrinolytic agent, is commonly used in cardiac surgery with cardiopulmo- nary bypass to reduce bleeding. We report two cases of convulsive seizures after cardiac surgery with chronic kidney disease on hemodialysis. The two patients underwent aortic valve replacement, one for aortic valve regurgitation and another for aortic valve stenosis, with cardiopulmonary bypass uneventfully. A total dose of 8 g of TA was administered intravenously; 4 g during and 4 g after cardiopulmonary bypass. Both patients developed two episodes of gener- alized convulsive seizures post-operative day 1, which were suppressed by administration of diazepam intra- venously. The blood test, brain CT and electroenceph- alogram revealed no significant abnormalities. They were discharged without any neurological complica- tions. The high dose of TA was considered to have caused the seizures, since in previous reports the use of TA during surgery was associated with increased risk for postoperative seizures. It was demonstrated that approximately 40 to 70% of TA is excreted in the urine following intravenous administration. We posit that this might have led to excessive serum concen- tration of TA in our patients. Therefore, the dosage of TA should be decreased judiciously in patients with chronic kidney disease especially on hemodialysis to prevent postoperative seizures.

[Evaluation of the side effects of intravenous patient controlled analgesia after spine surgery].

BACKGROUND: We have adopted intrravenous patient controlled analgesia (IV-PCA) for spine surgery. We could not find reports about detailed examinations of the side effects of IV-PCA using morphine after spine surgery, so we investigated retrospectively side effects in cases using morphine IV-PCA. METHODS: Eighty-five patients underwent IV-PCA after spine surgery. The contents of PCA pump were morphine 20 mg (= 2 ml), droperidol 2 mg (= 0.8 ml), and saline 77 ml. We fixed continuous infusion at 2 ml x hr(-1), bolus infusion at 2 ml x hr(-1), and lockout time at 15 minutes. Respiration time, SpO2, blood pressure, pulse rate, nausea and vomiting, and VAS were monitored while IV-PCA was in use. When severe side effects were noticed, IV-PCA was discontinued by physician in charge. We judged discontinuation of IV-PCA as occurrence of severe side effects. RESULTS: IV-PCA was discontinued in seven patients. The causes of discontinuation were nausea and vomiting, hypotension, and bradycardia. Nausea and vomiting was the most common cause and found mostly in women. CONCLUSIONS: Because IV-PCA was discontinuated in 8.2% of patients, it was thought that its management depending on patients' personal state was necessary to utilize IV-PCA as a method of postoperative analgesia.

[How much dosage of heparin do you administer? The relationship between heparin dosage and activated coagulation time (ACT) value during cardiovascular surgery: a multi center investigations].

BACKGROUND: In cardiac surgery, unfractionated heparin is widely used for anticoagulation. There are differences of heparin dosages among institutions for cardiac surgery with and without cardiopulmonary bypass (CPB). The aim of this clinical investigation is to find out the optimal dosage of heparin for initiation of CPB. METHODS: In cardiac cases with CPB, patients' weight, initial dosage of heparin, ACT values after heparin administration, product name of heparin and ACT measurement devices were recorded. RESULTS: There were significant differences in initial dosages of heparin, basal ACT values and increment of ACT values per units of heparin among institutions. CONCLUSIONS: A significant difference was revealed among institutions regarding the initial heparin dosage for CPB, in spite of the same target of ACT. There was no evidence to determine the optimal dosage of heparin for initiation of CPB.

[Anesthetic management for electroconvulsive therapy using target-controlled infusion of propofol].

A 66-year-old man received medical treatment of depression for several years. He had a suspected malignant syndrome and in addition the symptom had deteriorated, and the electroconvulsive therapy (ECT) was administered. Though suxamethonium chloride is usually used as a muscular relaxant in the electroconvulsive therapy, we used vecuronium bromide (VCB) considering malignant syndrome. Maintenance of anesthesia was necessary because of the long effect of VCB. Anesthesia was induced and maintained by target controlled infusion (TCI) of propofol. Because propofol suppresses the convulsion, it is necessary to adjust the depth of anesthesia by propofol, and we used TCI of propofol. When the predicted blood propofol concentrations were 1.5 microg x ml(-1) and 2.0 microg x ml(-1), electric stimulation was given to the patient and enough seizure duration was obtained. TCI of propofol is useful for ECT to patients for whom suxamethonium chloride can not be used.

[A case of nerve injury after vascular access surgery under brachial plexus block].

A 52-year-old woman underwent vascular access surgery under brachial plexus block of the left arm. After the surgery, the patient complained of painful and burning sensation and motor disturbance of her forearm without muscle necrosis. We administered ketamine to treat the symptoms as neuropathic pain arising as a complication of brachial plexus nerve block. Six days after operation, angiography showed little blood flow at distal portion of the shunt. We recognized ischemia induced monomeric neuropathy. Immediately after the occlusion of the vascular access, the pain disappeared but not sensory and motor disturbances. Our experience suggests that angiography is helpful for diagnosis of ischemia-induced neuropathy after vascular access surgery.

[A case of bradycardia in a patient with secondary hypothyroidism].

A 68-year-old patient was scheduled for subtotal gastrectomy. Preoperative examination showed heart rate of 30-40 beats.min-1 caused by secondary hypothyroidism. Triiodothyronine and thyroid stimulating hormone concentrations were 1.9 pg.ml-1 and 0.17 microU.ml-1 respectively. To treat bradycardia, the patient was given isoproterenol hydrochloride (ISP: 0.01-0.03 microgram.kg-1.hr-1) for 5 days before surgery. Heart rate recovered to 70-80 beats.min-1, and the dosage could be tapered off before surgery without return of bradycardia. The operation was performed successfully under general anesthesia. We reported the anesthetic management of this patient with severe bradycardia due to secondary hypothyroidism. This case suggests that preoperative treatment for the symptoms is important for anesthetic management of a patient with hypothyroidism.