Remimazolam anaphylaxis in a patient not allergic to brotizolam: a case report and literature review.

BACKGROUND: Remimazolam is a recently developed, ultrashort-acting benzodiazepine that is used as a general anesthetic. Some cases of remimazolam anaphylaxis have been reported, but its characteristics are not fully understood. We present an interesting case report and review of the literature to better understand remimazolam anaphylaxis. CASE PRESENTATION: A 75-year-old man scheduled for robot-assisted gastrectomy was administered remimazolam for the induction of general anesthesia. After intubation, low end-expiratory CO2, high airway pressure and concurrent circulatory collapse were observed. Bronchoscopy revealed marked tracheal and bronchial edema, which we diagnosed as anaphylaxis. The patient suffered cardiac arrest after bronchoscopy but recovered immediately with intravenous adrenaline administration and chest compressions. We performed skin prick tests for the drugs used during induction except for remimazolam, considering the high risk of systemic adverse reactions to remimazolam. We diagnosed remimazolam anaphylaxis because the skin prick test results for the other drugs used during anesthesia were negative, and these drugs could have been used without allergic reactions during the subsequent surgery. Furthermore, this patient had experienced severe anaphylactic-like reactions when he underwent cardiac surgery a year earlier, in which midazolam had been used, but it was not thought to be the allergen at that time. Based on these findings, cross-reactivity to remimazolam and midazolam was suspected. However, the patient had previously received another benzodiazepine, brotizolam, to which he was not allergic, suggesting that cross-reactivity of remimazolam may vary among benzodiazepines. In this article, we reviewed the 11 cases of remimazolam anaphylaxis that have been described in the literature. CONCLUSIONS: Remimazolam is an ultrashort-acting sedative; however, it can cause life-threatening anaphylaxis. In addition, its cross-reactivity with other benzodiazepines is not fully understood. To increase the safety of this drug, further research and more experience in its use are needed.

Real-time monitoring of cortical brain activity in response to acute pain using wide-area Ca2+ imaging.

Previous human and rodent studies indicated that nociceptive stimuli activate many brain regions that is involved in the somatosensory and emotional sensation. Although these studies have identified several important brain regions involved in pain perception, it has been a challenge to observe neural activity directly and simultaneously in these multiple brain regions during pain perception. Using a transgenic mouse expressing G-CaMP7 in majority of astrocytes and a subpopulation of excitatory neurons, we recorded the brain activity in the mouse cerebral cortex during acute pain stimulation. Both of hind paw pinch and intraplantar administration of formalin caused strong transient increase of the fluorescence in several cortical regions, including primary somatosensory, motor and retrosplenial cortex. This increase of the fluorescence intensity was attenuated by the pretreatment with morphine. The present study provides important insight into the cortico-cortical network during pain perception.

Pericapsular nerve group block for osteoarthritis-related chronic hip joint pain: a case report.

BACKGROUND: Pericapsular nerve group (PENG) block has shown effectiveness for acute hip pain associated with fractures and surgery. Herein, PENG block was performed for osteoarthritis (OA)-related chronic hip joint pain. CASE PRESENTATION: A 65-year-old woman presented left hip pain. She had bilateral hip osteoarthritis that improved with medications; however, a fall resulted in left hip pain. She experienced severe pain on movements, which required walking aids. To alleviate the hip pain, a PENG block was performed under ultrasound guidance. Transient muscle weakness occurred in 2 of 5 times. After 5 blocks, she regained the ability to walk without assistive devices. Pain did not recur even after 6 months. CONCLUSIONS: Repeated PENG blocks of short-acting local anesthetics alone could be an effective pain management technique for chronic hip pain. For safety, the appropriate injection site and local anesthetic dosage must be carefully considered.

Anesthetic management of a patient with Freeman-Sheldon syndrome undergoing oral surgery: A case report.

In the anesthetic management in this case was how to manage the patient without causing respiratory depression and respiratory muscle fatigue.

Perioperative management of thyroglossal duct cystectomy in a pediatric patient: A case report.

Thyroglossal duct on the dorsum of the tongue in the pediatric patient can cause a difficult airway due to the large mass and risk of airway obstruction associated with a swollen tongue after surgery.

Comparison of disinfection effect between benzalkonium chloride and povidone iodine in nasotracheal intubation: a randomized trial.

BACKGROUND: Nasotracheal intubation can potentially result in microbial contamination from the upper respiratory tract to the lower respiratory tracts. However, an ideal nasotracheal disinfection method is yet to be determined. Therefore, we compared the disinfection effects between benzalkonium chloride and povidone iodine in nasotracheal intubation. METHODS: Overall, this study enrolled 53 patients aged 20-70 years who were classified into classes 1 and 2 as per American Society of Anesthesiologists-physical status and were scheduled to undergo general anesthesia with NTI. Patients who did not give consent (n = 2) and who has an allergy for BZK or PVI were excluded from the study. The patients were randomly divided into two groups on the basis of the disinfection method: BZK (n = 26, one patient was discontinued intervention) and PVI (n = 25). 50 patients were assessed finally. The subjects' nasal cavities were swabbed both before (A) and after disinfection (B), and the internal surface of the endotracheal tube was swabbed after extubation (C). The swabs were cultured on Brain heart infusion agar and Mannitol salt agar. The number of bacteria per swab was determined and the rates of change in bacterial count (B/A, C/B) were calculated. The growth inhibitory activity of the disinfectants on Staphylococcus aureus were also investigated in vitro. RESULTS: Although the initial disinfection effects (B/A) were inferior for benzalkonium chloride compared with those for povidone iodine, the effects were sustained for benzalkonium chloride (C/B). In the in vitro growth inhibitory assay against S. aureus, benzalkonium chloride showed higher inhibitory activity than povidone iodine. CONCLUSION: Although both disinfectants were inactivated or diffused/diluted over time, benzalkonium chloride maintained the threshold concentration and displayed antimicrobial effects longer than povidone iodine; therefore, benzalkonium chloride appeared to show a better sustained effect. Benzalkonium chloride can be used for creating a hygienic nasotracheal intubation environment with sustained sterilizing effects. TRIAL REGISTRATION: UMIN-CTR (Registration No. UMIN000029645 ). Registered 21 Oct 2017.

Subglottic stenosis due to an unexpected foreign body diagnosed after emergency tracheostomy in a child.

BACKGROUND: Subglottic stenosis is a known complication of traumatic and prolonged endotracheal intubation. It is rare that the causes of severe subglottic stenosis are revealed to be an unexpected foreign body after airway securement in a child. Subglottic stenosis in a child is often associated with airway emergency, and management of difficult airway may be required. CASE PRESENTATION: We report the case of an 8-year-old girl with severe subglottic stenosis who required emergency tracheostomy. Emergency tracheostomy was performed under regional anesthesia. Sevoflurane was administered with sufficient titration to maintain spontaneous breathing. At first, the cause of severe subglottic stenosis was thought to be a traumatic event that had occurred 1 month previously; however, subsequent laryngoscopy revealed that the cause of subglottic stenosis was a foreign body. CONCLUSIONS: Management of the airway in a child with severe subglottic stenosis should be selected according to each patient's individual circumstances.

General Anesthetic Management of a Patient With Hypertrophic Cardiomyopathy for Oral Surgery: Did Digitalis Contribute to Bradycardia?

Stabilization of circulatory dynamics is a critical issue in the anesthetic management of patients with hypertrophic cardiomyopathy (HCM). In this report, we managed general anesthesia for a 74-year-old male patient with nonobstructive HCM who developed circulatory instability intraoperatively. Severe bradycardia measuring 35 beats/min and hypotension measuring 78 mm Hg systolic were observed during surgery. Using stroke volume variation and stroke volume from the FloTrac as indices, successful circulatory management was performed with dopamine. The hypotension and bradycardia were thought to be the result of methyldigoxin and possibly associated with our perioperative management. Cardiology consult should have been obtained. We demonstrated that the FloTrac can be beneficial in diagnosing and managing cardiovascular instability and administration of dopamine in the anesthetic management of nonobstructive HCM patients.

General Anesthetic Management of a Child With Horseshoe Lung and Left Lung Hypoplasia for Cheiloplasty: A Case Report.

Horseshoe lung is an extremely rare congenital malformation in which the right and left lungs are fused due to stenosis of the lung parenchyma. In anesthetic management, it is important to avoid hypoxemia and hypercapnia caused by a decline in lung capacity and functional residual capacity. A 3-year-old boy with horseshoe lung and left lung hypoplasia was scheduled to undergo cheiloplasty. Regarding respiratory management, to prevent hypoxemia and hypercapnia, we avoided intraoperative peripheral airway obstruction with positive end-expiratory pressure, set a long inspiratory phase time for sufficient alveolar expansion, and maintained sufficient gas exchange in lungs with low reserve capacity.

Two Cases of Duchenne Muscular Dystrophy That Showed Different Reactions to Nerve Stimulation During Peripheral Nerve Block: A Case Report.

In recent years, the technique of combined ultrasound and electrical stimulation-guided nerve block has been recommended. We present 2 patients with Duchenne muscular dystrophy who exhibited different muscle responses to nerve stimulation during the performance of peripheral nerve blocks for surgeries. Whereas a 2-year-old boy without severe disability showed the expected muscle contraction to electrical nerve stimulation, a 14-year-old boy with severe disability showed no muscle response. Our experience suggests that muscle responses to electrical nerve stimulation will vary with the stage of Duchenne muscular dystrophy.

Estimation of the success rate of anesthetic management for thymectomy in patients with myasthenia gravis treated without muscle relaxants: a retrospective observational cohort study.

Although maintaining anesthesia for myasthenia gravis (MG) with minimal muscle relaxants (MR) is common, the success rate of anesthetic management for MG without MR is not clear. We therefore retrospectively examined the success rate of anesthetic management for MG without MR among 66 consecutive cases of thymectomy for MG performed at our hospital between January 2004 and April 2010, before approval of using sugammadex. A total of 60 patients (90.9 %) were treated without MR (N group). Among the 60 cases, 17 (28.3 %) patients were not extubated in the operating room due to postoperative respiratory depression or other reasons. Therefore, the success rate of anesthetic management for thymectomy in patients with MG without treating MR was 71.7 % (43/60) [95 % confident interval (CI): 65.9-77.5 %]. The reasons for using MR included coughing at intubation in one case, bucking during surgery in two cases, and MR was considered to be safer by the attending anesthesiologist in three cases. The number of cases of impossible extubation requiring ventilation on that day was three in the N group and none in the R group. Finally, the success rate of anesthetic management for MG without MR was estimated to be 71.1 % (95 % CI: 65.9-77.5 %).

[Effects of anesthetics on the higher brain function].

Number of surgeries for the elderly is increasing year by year. Postoperative cognitive dysfunction, POCD, and delirium are typical failure's of higher brain function after surgery. The mechanism of POCD and delirium has been suggested to be associated with inflammation, but its details are unknown. Alzheimer's disease leads to derangement in cognitive function. The number of patients with Alzheimer's disease is expected to increase rapidly. There is a possibility that inhalation anesthesia exacerbates the pathology of patients with impaired higher brain function such as Alzheimer's disease. On the other hand, the another suspect, that propofol is safe. However, it should be recognized that these results became clear by basic research. Further clinical study is required.

Orotracheal intubation with an AirWay Scope in a patient with Treacher Collins syndrome.

Treacher Collins syndrome (TCS) is a congenital malformation of craniofacial development; in these patients conventional direct laryngoscopy is very difficult and often unsuccessful because of the upper airway malformation. A 20-year-old man with TCS was scheduled for elective tympanoplasty. The patient showed the characteristic facial appearance of TCS, and a difficult airway was anticipated. After careful anesthesia induction, direct laryngoscopy with Macintosh blade no. 4 of a direct laryngoscope failed to visualize the epiglottis, even with cricoid pressure, resulting in a grade 4 Cormack and Lehane view. Next, the AirWay Scope was easily inserted, and his glottic opening was clearly visualized. An 8.0-mm-internal-diameter tracheal tube was then advanced into the trachea without any difficulty. The AirWay Scope is a very useful airway device for orotracheal intubation; it provides an excellent view of the glottis without requiring alignment of the oral, pharyngeal, and laryngeal axes, and appears to be promising for use in patients with a difficult airway.

Circulatory collapse caused by unnoticed hypermagnesemia in a hospitalized patient.

We report a case of hypermagnesemia in a hospitalized patient after prolonged laxative use; due to preexisting impaired consciousness and digestive problems, the hypermagnesemia was difficult to detect until it almost became fatal. A 64-year-old man who was a patient at another hospital for treatment of head injury and gastric ulcer had developed circulatory collapse and was transferred to our hospital. Hypermagnesemia (serum magnesium concentration 11.0 mg.dl(-1)) was thought to be the cause of the circulatory collapse and treatments were successful. A magnesium laxative had been administered for more than a month at the previous hospital, but the patient's serum magnesium level was never measured. Care should be taken when a magnesium laxative is administered to patients who already have impaired consciousness and digestive problems that are early symptoms of hypermagnesemia.

Anesthetic management of a patient with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) during laparotomy.

A 53-year-old man with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) underwent a gastrectomy. We administered bicarbonated Ringer's solution, which has a physiological concentration of bicarbonate. The level of serum lactate did not increase significantly, and metabolic acidosis did not occur throughout surgery or for 3 h after surgery. Aggressive warming was needed to maintain normothermia, presumably because the mitochondrial respiratory chain, which is responsible for thermogenesis, is impaired in MELAS patients. It is important to maintain normothermia in MELAS patients in order to avoid further mitochondrial metabolic depression.

Flexible, tapered-tip tube facilitates conventional orotracheal intubation by novice intubators.

Orotracheal intubation is the standard technique for airway management, but several untoward airway complications are possible with this method. To avoid airway trauma caused by the tube tip during intubation, the Parker Flex-Tip tube (PFT), which has a flexible, tapered tip, was developed. It has been reported that the PFT facilitates fiberoptic orotracheal intubation and introducer-guided tracheal intubation. In this study, we compared the PFT to a standard endotracheal tube (SET), regarding the time of intubation during conventional orotracheal intubation and the incidence of postoperative sore throat and hoarseness. One hundred and thirty-four patients scheduled for elective anesthesia using orotracheal intubation were randomized to either the PFT or SET and 132 completed the study. The intubators were classified into three groups: staff anesthesiologists, inexperienced anesthesiologists, and anesthesia trainees. The tube was selected by another anesthesiologist and the time required for intubation was measured. PFT did not shorten the time required for intubation and did not reduce the incidence of sore throat and hoarseness. However, a detailed analysis revealed that the PFT decreased the time required for intubation in the anesthesia trainee group. The PFT may help novice intubators to conduct a smooth intubation.

Postextubation airway management with nasal continuous positive airway pressure in a child with Down syndrome.

We describe our experience with use of variable-flow nasal continuous positive airway pressure (NCPAP) to manage postextubation stridor in a 31-month-old child with Down syndrome (DS). Although it has been recognized that children with DS tend to develop obstruction of the upper airway postoperatively, little is known concerning appropriate management of this situation. Although there are surprisingly few reports of use of variable-flow NCPAP for children older than preterm infants, we successfully treated postextubation ventilatory complications by providing variable-flow NCPAP without complications such as pneumothorax.