Successful reversal of remimazolam anesthesia in a "cannot intubate, can ventilate" situation: a case report.

BACKGROUND: Compared to other intravenous anesthetics, availability of a specific antagonist flumazenil is a clear advantage of remimazolam. We report a patient who could be rapidly woken up when laryngoscopy and tracheal intubation were unexpectedly difficult. CASE PRESENTATION: A 62-year-old man was scheduled to have resection of a small gingival tumor. Preoperative airway examination was unremarkable except for an omega-shaped epiglottis. Anesthesia was induced with remifentanil/remimazolam infusion and rocuronium. A small omega-shaped edematous epiglottis precluded identification of glottis. Consciousness and spontaneous ventilation were rapidly restored after administration of flumazenil and sugammadex. Tracheostomy was done under local anesthesia while the patient breathed spontaneously. CONCLUSIONS: Remimazolam can be a reasonable induction agent when there are concerns regarding airway management. Avoiding repeated airway manipulations is extremely important to prevent deterioration into a "cannot intubate, cannot ventilate (CICV)" emergency.

Coagulation assessment with thromboelastography during abdominal endovascular aneurysm repair in a patient with hemophilia A.

BACKGROUND: As both APTT and APTT-based coagulation method cannot distinguish heparin effect from intrinsic coagulation factor deficiency, we implemented thromboelastography (TEG) for the coagulation assessment in a patient with hemophilia A undergoing an endovascular surgery with heparinization. CASE PRESENTATION: A 68-year-old male with hemophilia A underwent endovascular aortic repair for abdominal aortic aneurism. TEG results showed recovery of coagulation time (R) in both kaolin assay (CK) and kaolin-heparinase assay (CKH) after factor VIII replacement before heparinization. Against our expectations, R-CKH was slightly prolonged (9.0 min) during heparinization. After the administration of protamine sulfate, R in both assays showed similar values within the normal ranges. CONCLUSIONS: The combination of CK and CKH assays could be useful to estimate factor VIII (FVIII) level when heparin concentration is low or without heparin; however, caution should be necessary for estimation of FVIII level by TEG under the effect of medium- or high-dose heparin.

Effect of availability of video laryngoscopy on the use of fiberoptic intubation in school-aged children with microtia.

BACKGROUND: With the increasing popularity of video laryngoscopy during intubation of pediatric patients with normal or difficult airways, fiberoptic-assisted tracheal intubation, traditionally considered the gold standard for difficult intubation, may become underused. AIM: We aimed to assess the use of airway management techniques before and after introduction of video laryngoscopy in a cohort of school-aged children with microtia, who are at increased risk of difficult intubation. METHODS: We retrospectively reviewed intubation devices used for all pediatric patients with microtia who had undergone reconstructive ear surgery at a single institution during the period January 2008 to December 2012. In each case, we identified the original airway management technique and success rate, as well as success rate for subsequent rescue techniques. The use of fiberoptic-assisted tracheal intubation was compared before and after introduction of a pediatric blade for the Pentax-AWS video laryngoscope. RESULTS: This study included 537 consecutive intubation procedures; 264 before and 273 after introduction of the pediatric airway scope. Elective use of fiberoptic-assisted tracheal intubation for anticipated difficult intubation was significantly less after introduction of the pediatric airway scope (before: 19 of 79, 24% vs after: 3 of 79, 4%; odds ratio 8.02; 95% confidence interval, 2.27 to 28.39; P = .0003), which achieved a 100% success rate when used as the primary technique in both routine and difficult airways. All 5 cases of failed direct laryngoscopy were rescued by the pediatric airway scope, thus eliminating emergency use of fiberscopy. CONCLUSION: Introduction of a pediatric video laryngoscope resulted in a substantial decrease in the use of fiberoptic-assisted tracheal intubation. This change in intubation method might not influence the success rate of intubation in experienced hands but could be relevant for novice users.

[Current practice of pediatric airway management].

Recent advances in pediatric airway management contribute to a significant decrease in morbidity and mortality in pediatric anesthesia. This article reviews the current concept of routine and difficult pediatric airway with special emphasis on preoperative pediatric airway assessment. Newly introduced airway devices designed for pediatric patients may facilitate ventilation and intubation although their efficacy and safety profiles in routine and difficult situations remain undetermined. Based on the pediatric protocol recently published by the Difficult Airway Society (DAS), we discuss structured algorithms for unanticipated difficult pediatric airway. Simulation technology will aid acquisition and retention of pediatric airway management skills.

Incidence and neurological outcomes of aneurysm rupture during interventional neuroradiology procedures in a hybrid operating suite.

A hybrid operating suite, where craniotomy, brain CT scanning, fluoroscopy, and angiography can be performed on the same operating table, is becoming popular among neurosurgeons. However, whether use of a hybrid operating suite can improve neurological outcome has not been studied. We reviewed the incidence and outcomes of ruptures of cerebral vascular lesions during interventional neuroradiology procedures performed in our hybrid operating suite. Of 602 patients who underwent coil embolization under general anesthesia, five cases of intraprocedural rupture of the aneurysms were identified. Despite emergency neurosurgical intervention within 2 h of rupture of the aneurysms, two of these five patients died and one patient had permanent neurological deficit postsurgery. Whether use of a hybrid operating suite improves neurological outcome remains uncertain.

Application of gum elastic bougie to nasal intubation.

Gum elastic bougie (GEB), a useful device for difficult airway management, has seldom been used for nasotracheal intubation. Among 632 patients undergoing dental procedures or oral surgery, GEB was used successfully in 16 patients in whom conventional nasal intubation had failed because of anatomical problems or maldirection of the tip of the tracheal tube. We recommend that GEB should be applied from the first attempt for nasal intubation in patients with difficult airways.

[Postoperative analgesia after remifentanil].

Providing analgesia is the most important, yet the most difficult aspect of remifentanil anaesthesia, as its effect wears off quickly after infusion is terminated. Longer-acting opioids such as morphine and fentanyl must be given well before patients wake up. Bolus administration of fentanyl approximately 20 minutes before the end of surgery may provide adequate analgesia at emergence and tracheal extubation. However, fentanyl concentration decreases quite rapidly and patients may need repeated dosing until analgesia is attained. Continuous intraoperative low-dose infusion of fentanyl may lead to better analgesia than bolus dosing, because its context-sensitive half-time increases as the infusion lasts longer. Regional anaesthetic technique, such as epidural analgesia and peripheral nerve block can also be used in patients without coagulation abnormalities. Issue of acute tolerance after intraoperative use of remifentanil still awaits further study before final conclusion is reached. Some data suggest that we should not use an unnecessary and high dose of opioid without clear indication. Theoretically, remifentanil infusion can be used in ICU and surgical wards to manage postoperative pain in ventilated as well as spontaneously breathing patients. However, in some susceptible patients, even a very low-rate infusion can still cause significant respiratory depression more than 30 minutes after starting infusion. Pulse oximetry is not sensitive enough to detect early ventilatory depression when patients breathe oxygen-enriched air. Without continuous observation by trained anaesthetists, infusion of remifentanil should not be used casually particularly in non-ventilated patients.

[Randomized, multicenter study of interaction between Org 9426 (rocuronium bromide) and anesthetic agents in Japanese population].

BACKGROUND: The purpose of this randomized, multi-center phase III trial was to investigate the influence of sevoflurane and propofol on the neuromuscular blocking effects and pharmacokinetic parameters of Org 9426 (rocuronium bromide) in Japanese population. METHODS: Thirty-nine adult Japanese patients participated in this randomized, multi-center study. Neuromuscular function was monitored continuously with TOF-Watch SX (Organon NV, Netherlands) after anesthetic induction with propofol. These subjects randomly received either 0.6 mg x kg(-1) or 0.9 mg x kg(-1) of rocuronium for endotracheal intubation. These two groups were further divided to two anesthetic regiments : sevoflurane group and propofol group. The difference in onset and recovery of rocuronium-induced neuromuscular block was statistically analyzed with two-way ANOVA. RESULTS: Mean duration for maximal block was 76 seconds and 66 seconds, respectively. The duration between Org 9426 administration and 25% recovery of first twitch response was significantly prolonged in patients given 0.9 mg x kg(-1) of Org 9426. Sevoflurane also significantly increased this duration. However, the serum concentration of Org 9426 was not statistically different between the four study groups. CONCLUSIONS: The duration of Org 9426-induced neuromuscular blockade was significantly increased under sevoflurane anesthesia compared to propofol anesthesia. This difference may be attributed to pharmacodynamic change.

Continuous spinal anesthesia and postoperative analgesia for elective cesarean section in a parturient with Eisenmenger's syndrome.

We describe the use of continuous spinal anesthesia (CSA) for an elective cesarean section in a 29-year-old parturient with Eisenmenger's syndrome at 30 weeks of gestation. It is essential in patients with Eisenmenger's syndrome to prevent significant increases in right-to-left shunt following the reduction in systemic vascular resistance. In this case, the patient hoped to be awake during the operation because of her fear of death. We therefore applied CSA to this patient because single-shot spinal anesthesia and epidural anesthesia might cause sudden cardiovascular depression. In fact, sudden cardiovascular changes were avoided by the titration of local anesthetics and the operation was uneventful, although prompt treatment of hypotension was essential and adjustment of the anesthetic levels was difficult. Postoperative patient-controlled spinal analgesia provided satisfactory pain relief with hemodynamic stability and no significant side effects. However, thorough experience with the requisite techniques is critical in CSA because of the technical difficulty of the procedure, and anesthesiologists must gain such experience in less-demanding cases before attempting to administer it in patients presenting extreme challenges as described in this case report.

Titration of propofol infusion using processed electroencephalogram during combined general and spinal anesthesia.

PURPOSE: To determine the necessary mean infusion rate of propofol during combined nitrous oxide (N2O) and propofol spinal anesthesia by using the processed electroencephalogram (pEEG). METHODS: Twelve elective gynecological patients were monitored by a Dräger pEEG monitor under N2O and propofol spinal anesthesia. To make it easier to detect an inadequate depth of anesthesia, muscle relaxants were not given and the patients breathed spontaneously through a laryngeal mask airway. Manual step-down infusion of propofol was employed to provide intraoperative hypnosis. Propofol infusion was titrated to maintain cardiorespiratory parameters within 20% of baseline and the 90th percentile of the spectral edge frequency (SEF 90) of the pEEG between 10 and 13.5 Hz. RESULTS: The mean (SD) induction dose of propofol was 2.9 (0.4) mg·kg-1. The mean (SD) maintenance infusion rate was 4.2 (0.5) mg·kg-1·h-1. The mean (SD) time from the end of propofol infusion to the opening of the patient's eyes was 5.4 (2.0) min. No gross movements or intraoperative awareness was recognized. The mean (SD) SEF 90 during the maintenance of anesthesia was 12.2 (1.5) Hz, which increased significantly to 16.2 (1.9) Hz at 1 min before the patients opened their eyes in reponse to verbal commands. CONCLUSION: Titration of propofol infusion using SEF during combined general and spinal anesthesia provided a rapid recovery without any clinical signs of inadequate anesthesia.