Anesthesia Management via an Automated Control System for Propofol, Remifentanil, and Rocuronium Compared to Management by Anesthesiologists: An Investigator-Initiated Study.

BACKGROUND: We previously developed an automated total intravenous anesthesia control system that uses new closed-loop system algorithms to administer propofol, remifentanil, and rocuronium based on the bispectral index and train-of-four data. We recently improved this automated control system by adding a safety mechanism and using a modified monitoring device. METHODS: Patients scheduled for elective surgery were randomly assigned to closed-loop feedback control (automatic group) or the manual administration of propofol, remifentanil, and rocuronium (manual group). The proportion of time during which the proper management of three-agent anesthesia was maintained during surgery was determined as the primary endpoint. RESULTS: The proportion of time during which the three components of sedation, analgesia, and muscle relaxation were adequately controlled was 87.21 ± 12.79% in the automatic group, which was non-inferior to the proportion of 65.19 ± 20.16% in the manual group (p < 0.001). Adverse events during the operative or postoperative observation periods were significantly less frequent in the automatic group (54 patients, 90.0%) than in the manual group (60 patients, 100.0%; p = 0.027). CONCLUSION: Our three-agent automated control system, which features an improved muscle relaxation monitor and safety mechanism added to the basic control algorithms, maintained sedation, analgesia, and muscle relaxation appropriately in a manner non-inferior to anesthesiologists without compromising safety.

Theoretical and evidence-based infection control during general anesthesia in the COVID-19 pandemic.

With the outbreak of COVID-19, attention has focused on measures to prevent droplet infection. Operating rooms, where we anesthesiologists mainly work, are equipped with various theories and techniques for performing surgical procedures and general anesthesia on patients with various infectious diseases, whether airborne, droplet, or contact infection, and are an environment where surgical procedures and general anesthesia can be safely performed on patients with compromised immune functions. Here, we describe the anesthesia management standards assuming COVID-19 from the viewpoint of medical safety, as well as the structure for supplying clean air in the operating room and the structure of a negative-pressure operating room.

Three cases of difficulty in achieving definitive loss of consciousness with remimazolam.

BACKGROUND: Remimazolam is a novel, ultra-short-acting benzodiazepine used for general anesthesia. Because remimazolam is an emerging drug, the tolerance to remimazolam in benzodiazepine-taking patients has been unclear. Also, the efficacy of remimazolam in different races is not fully elucidated so far. CASE PRESENTATION: Here we experienced three cases in which high dose of remimazolam was needed for attempting to achieve appropriate anesthetic depth. Two of the three cases were of preoperatively benzodiazepine-taking patients. The other was a case of a Chinese patient. In all three cases, conversion to general anesthesia with propofol was necessitated. CONCLUSIONS: When signs of inadequate sedative effect of remimazolam are observed in patients of benzodiazepine users or of different races, conversion to another sedative agent such as propofol should be considered.

Anesthetic management of pulmonary artery replacement for idiopathic dilatation of the pulmonary artery with a Kommerell's diverticulum: a case report.

BACKGROUND: Idiopathic dilatation of the pulmonary artery (IDPA) is a rare condition in which the pulmonary artery dilates without an obvious cause. Pulmonary artery replacement is indicated in severe cases to prevent serious complications. CASE PRESENTATION: A 59-year-old man was diagnosed with an IDPA of 64 mm and Kommerell's diverticulum (aortic aneurysm located at the aberrant left subclavian artery). A computed tomography scan revealed slight compression of the aneurysm to the trachea, although not interfering with airway management. The surgical approach was a median sternotomy, and cardiopulmonary bypass was established through aortic and bicaval cannulations. The perioperative course was uneventful. CONCLUSIONS: To prevent injury to the dilated pulmonary artery, a strategy for cardiopulmonary bypass and a surgical approach should be discussed beforehand. As dilatation of the pulmonary artery is often complicated by anatomic abnormalities, preoperative evaluation should be aimed at appropriate assessments using imaging modalities.

[Cytoreductive Surgery Performed Twice for Pseudomyxoma Peritonei with Pleural Extension of Mucinous Tumor].

Pseudomyxoma peritonei (PMP) is a condition characterized by production of a large amount of mucopolysaccharides by neoplastic epithelium, with intraabdominal cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) known to be viable treatment options. Pleural extension from an PMP is unusual and thought to be related to diaphragmatic perforation during surgery or transdiaphragmatic spreading of the disease through the lymphatic lacunae. Here, we report a patient with PMP with pleural extension of a mucinous tumor for whom CRS was performed twice. A 57-year-old female with PMP infiltrating the right chest cavity was scheduled for two separate CRS and hyperthermic chemotherapy procedures, because of the highly invasive characteristics of the surgery. For the first operation, we performed intra-abdominal surgery under general anesthesia combined with epidural anesthesia. To assess fluid and blood transfusion responsiveness, and reactions to vasoactive medication, we utilized an arterial pressure-based cardiac output monitor and central venous oximetry catheter. The second operation was performed 5 months later under general anesthesia with differential lung ventilation combined with epidural anesthesia. The operation and anesthesia for both surgical procedures were uneventful.

[A case of large tracheoesophageal fistula after repair of the right discending aortic arch].

A 77-year-old woman with right aortic arch was diagnosed as aortic dissection (De Bakey IIIb) and hospitalized for conservative treatment. But, her respiratory condition deteriorated due to tracheal stenosis with aortic dissection. Surgical graft replacement of the descending aorta was performed to release tracheal stenosis. Six days after surgery, tracheoesophageal fistula (TEF) was noticed. The size of the fistula was 3 cm in diameter, located 3cm to the oral side from the carina and 23 cm from the incisors. Nineteen days after surgery, an esophageal stent was placed leading to temporary improvement of the respiratory status, but it aggravated again. Unfortunately, she died due to ventricular fibrillation 26 days after surgery. The case is extremely rare with dissection of the right aortic arch. Such a case is considered to be a high risk of TEF, and it is necessary to perform early preventive measures.

[A survey of perioperative asthmatic attack among patients with bronchial asthma underwent general anesthesia].

BACKGROUND: We investigated the risk factor of perioperative asthmatic attack and effectiveness of preventing treatment for asthmatic attack before operation. METHODS: We performed retrospective chart review of one hundred eleven patients with asthma underwent general anesthesia and surgical intervention from January 2006 to October 2007 in our hospital. RESULTS: The rate of perioperative asthmatic attack were as follows; 10.2% (5 in 49 cases) in no pretreatment group, 7.5% (3 in 40 cases) in any pretreatments except for systemic steroid, and 4.5% (1 in 22 cases) in systemic steroid pretreatment group. Neither preoperative asthma severity nor duration from the last attack had significant relevancy to perioperative attack rate. The otolaryngological surgery, especially those have nasal polyp and oral surgery had high perioperative asthma attack rate, although there was no significant difference. CONCLUSION: We recommend the systemic steroid pretreatment for asthmatic patients, especially when they have known risk factor such as administration of the systemic steroid within 6 months, or possibly new risk factor such as nasal polyp, otolaryngological and oral surgery.

[Trends of HIV patients operated at International Medical Center of Japan].

BACKGROUND: HIV-infected patients are on the increase in Japan, and anti-HIV therapy improved their prognosis. It is expected that the number of operations in HIV patients will increase. METHODS: We surveyed the prevalence of HIV 30,188 patients operated at International Medical Center of Japan, a major, HIV/AIDS hospital, from 2001 to 2007. RESULTS: The number of HIV-positive cases was 389 in 7 years, and the prevalence of HIV seropositivity was 1.3% in total, 1.0% in scheduled, and 2.0% in emergent cases. The prevalence of male (2.0%) was higher than female (0.7%) patients and the prevalence was highest (9.2%) in male patients in their 30's. They were parallel with the HIV occurrence trend of Japan. The prevalence was the highest (2.4%) in the division of general surgery, as well as in obstetric and gynecology. The number of major surgery in HIV patients has been increasing. CONCLUSIONS: We assume that the perioperative management in each hospital has become more important. The annual trend of the number of the operations performed in HIV-positive patients at our hospital did not show annual changes.

[Current status of HIV/AIDS anesthetic experiences in Japan--questionnaire for anesthesia teaching hospitals].

BACKGROUND: As the number of HIV-infected patients in Japan increases every year, the opportunity for a HIV-positive patient to undergo an operation is also increasing. METHODS: Authors sent questionnaire to 952 anesthesia teaching hospitals, in order to investigate the experience and management of the HIV-positive anesthetic cases. RESULTS: The reply was obtained from 480 teaching hospitals. One hundred and nine hospitals (22.7%) experienced HIV-positive operation, 367 hospitals (76.5%) had no experience. With regard to the number of experienced HIV-positive cases, only one case was the most numerous answer and most of the hospitals had fewer than ten cases. General anesthesia was selected in 74% of cases, regional anesthesia (spinal or/and epidural anesthesia) were selected in 26% of cases. Preoperative HIV examination for almost all scheduled cases were carried out in 24% of the hospitals, but 23% of the hospitals did not carry out the examination at all. Eighteen percent of the hospitals had a severe rule for the management of a HIV-positive case, and 58% of the hospitals had a rule almost the same as for HBV-HCV positive cases. CONCLUSIONS: Almost one fourth of anesthesia teaching hospitals experienced HIV-positive cases. Anesthesiologists should know how to manage HIV-positive surgical patients and be prepared for the cases.

Effect of bupivacaine enantiomers on Ca2+ release from sarcoplasmic reticulum in skeletal muscle.

Local anesthetics affect intracellular Ca2+ movement in the myocyte. The use of isomers may help to reveal specific mechanisms of action, such as receptor mediation. In the present study, we used skinned fibers from mammalian skeletal muscle to test whether bupivacaine enantiomers had different effects on Ca2+ release and uptake by the sarcoplasmic reticulum, and on the Ca2+ sensitivity of the contractile system. Ca2+-induced Ca2+ release was enhanced by S-bupivacaine 1 approximately 3 mM, but inhibited by R-bupivacaine 3 mM, remaining unaffected at lower doses. These enantiomers inhibited Ca2+ uptake to different degrees, with R-bupivacaine having a stronger effect. Ca2+ sensitivity of the contractile system was equally enhanced by R- and S-bupivacaine. These findings might help to explain the myoplasmic Ca2+ elevation induced by bupivacaine. The observed stereoselectivity suggests effects on specific proteins, the ryanodine Ry1 receptor and the Ca2+-ATPase pump, rather than non-specific increase in Ca2+ permeability.

[Two cases of pulmonary hypertension crisis in patients with primary pulmonary hypertension].

Primary pulmonary hypertension (PPH) is an uncommon disease. We describe two cases of pulmonary hypertension crisis in patients with PPH during general anesthesia. Any factor that worsens primary pulmonary hypertension (strain, hypoxia, pain, hypercapnia, intubation, or hyperinflation) should be avoided.

[Anesthetic management of pediatric renal transplantation: a review of 15 cases under the age of 10 years].

BACKGROUND: In pediatric renal transplantation, an adult kidney is transplanted to a small child and it may cause severe cardiovascular insufficiency. METHODS: The anesthetic management of 15 pediatric recipients younger than 10 years, undergoing living-related renal transplantation were analyzed retrospectively. RESULTS: Before the operation, 3 of 15 patients were receiving hemodialysis, and the others were receiving peritoneal dialysis. Isoflurane was used for the anesthetic maintenance in most of cases. Arterial and central venous pressures were monitored invasively in all cases. Pulmonary arterial catheters and transesophageal echocardiography were used in some patients with cardiac complications. For intraoperative fluid management, a total volume of 18 ml.kg-1.h-1 (mean) was infused, which included approximately 8 ml.kg-1.h-1 of crystalloid, 7 ml.kg-1.h-1 of fresh frozen plasma, and 2 ml.kg-1.h-1 of washed red blood cells. Dopamine 1-7 micrograms.kg-1.min-1 and human atrial natriuretic peptide (hANP) 0.05-0.1 microgram.kg-1.min-1 were administered as diuretics. None of 15 patients developed severe cardiovascular insufficiency of poor diuresis. CONCLUSIONS: Cardiovascular stability and good function of the transplanted kidney were maintained by appropriate monitoring and continuous intravenous infusion of dopamine and hANP. It is important to infuse enough volume of fluid and blood before recanalization.

Osteoporosis following chronic constriction injury of sciatic nerve in rats.

Osteopathic changes sometimes occur in patients with complex regional pain syndrome (reflex sympathetic dystrophy and causalgia). We aimed to investigate whether such osteopathic changes occurred in rats with chronic constriction injury (CCI) of the sciatic nerve. A CCI of the sciatic nerve was established in a unilateral hind limb in 39 adult Sprague-Dawley rats, which were killed 1, 2, 3, 5, or 7 weeks after the CCI procedure. Bone mineral content (BMC) and bone mineral density (BMD) in extracted tibial bones were measured using a dual-energy X-ray absorptiometer, and the number of osteoclasts in the metaphyseal regions was counted by the use of tartrate-resistant acid phosphate (TRAP) staining. BMC was significantly decreased, compared with that of the contralateral side, 1 to 7 weeks after CCI, and BMD was decreased 2 to 7 weeks after the procedure in the ipsilateral tibial bones, compared with BMD in the contralateral bones. The number of TRAP-positive multinucleated osteoclasts in the ipsilateral bones was significantly increased at 2, 3, and 5 weeks after the CCI, when compared with the number of these osteoclasts in the contralateral bones. The results of the present study demonstrate that osteopathic changes are associated with chronic constrictive injury of the sciatic nerve.