A Case of Surgery Cancellation Following the Discovery of Anisocoria After Induction of General Anesthesia.

Anisocoria after induction of general anesthesia may indicate a severe cerebrovascular disorder. We encountered a case in which anisocoria in the left and right eyes was noticed after induction of general anesthesia, and the surgery was canceled. The patient was a 53-year-old woman with a history of hypertension. She received general anesthesia 10 years ago, but the details were unknown. Anesthesia was induced with propofol, remifentanil, and rocuronium, followed by nasal intubation. No significant change was observed in vital signs during the induction of anesthesia. After intubation, the pupils were checked according to the protocol for observing pupil diameter. The pupil size was found to be unequal, measuring 1 mm in the left eye and 4 mm in the right eye. A cerebrovascular disorder was suspected; thus, the surgery was canceled, and the patient was awakened and extubated. Neurological symptoms such as limb movements were checked after awakening, and no disorientation or motor dysfunction was detected in the patient. However, her pupils remained unequal, measuring 2 mm in the left eye and 4 mm in the right eye. Regarding light reflex, the left eye was miotic, but the right eye remained mydriatic. The pupillary symptom persisted even during discharge the next day. Since our hospital is a solely dental hospital, following discharge, after consulting the ophthalmology department of a nearby medical university hospital, the patient was diagnosed with pupillotonia, as she had been experiencing light dazzling in only her right eye for seven years, had no light reflex but near reflex, and was miotic due to the use of pilocarpine hydrochloride eye drops, which promotes miosis. The patient has had these symptoms in the right eye for seven years, and it is possible that she had anisocoria during the preoperative examination at this time. If anisocoria had been detected and examined carefully during the preoperative examination, there would have been no need to cancel the surgery. In this case, we strongly felt that the pupils must be checked during the preoperative examination.

Usefulness of Continuous Low-Dose Fentanyl in Combination with Dexmedetomidine and Midazolam for Intravenous Sedation: A Randomised Controlled Trial.

Intravenous dexmedetomidine (DEX) and midazolam (MZ) are currently used to achieve sedation in dental surgery under local anaesthesia. However, the efficacy of low-dose fentanyl (FEN) in combination with DEX and MZ sedation remains unclear. Therefore, we implemented a prospective randomised controlled trial to investigate the intra- and postoperative analgesic effects, intraoperative respiratory and circulatory dynamics, and frequency of intra- and postoperative adverse events of continuous low-dose fentanyl administration with DEX and MZ sedation. Patients aged 20-64 years scheduled for dental surgery under sedation were randomly assigned to the DEX+MZ (DM) or DEX+MZ+FEN (DMF) group. DEX was administered at 4 µg/kg/h for 10 min and then reduced to 0.7 µg/kg/h until the end of surgery. MZ was administered at 0.04 mg/kg upon the initial administration of DEX and 0.02 mg/kg every hour thereafter. In the DMF group, FEN infusion was administered at 2 µg/kg/h during the initial administration of DEX and then reduced to 1 µg/kg/h after 10 min until the end of surgery. Primary outcomes were intra- and postoperative analgesic efficacies, whereas secondary outcomes were intraoperative respiratory and circulatory dynamics. The total amount of intraoperative local anaesthetic administered and the heart rate were significantly lower in the DMF group than in the DM group (P = 0.044 and P < 0.01, respectively). No significant difference was observed in the frequency of postoperative administration of analgesics and intra- and postoperative adverse events. These findings demonstrated that low-dose FEN infusion in combination with DEX and MZ sedation in dental surgery provides intraoperative analgesia and suppresses tachycardia with little effect on blood pressure and respiratory dynamics and without effect on postoperative analgesia.

The effect of various dilute administration of rocuronium bromide on both vascular pain and pharmacologic onset: a randomized controlled trial.

BACKGROUND: Rocuronium bromide (RB) is known to cause vascular pain. Although there have been a few reports that diluted administration causes less vascular pain, there have been no studies investigating diluted administration and the onset time of muscle relaxation. Therefore, we examined the influence of diluted administration of RB on the onset time of muscle relaxation and vascular pain. METHODS: 39 patients were randomly assigned to three groups: RB stock solution 10 mg/ml (Group 1), two-fold dilution 5 mg/ml (Group 2), or three-fold dilution 3.3 mg/ml (Group 3). After the largest vein of the forearm was secured, anesthesia was induced by propofol and 0.6 mg/kg of RB was administered. The evaluation method devised by Shevchenko et al. was used to evaluate the degree of vascular pain. The time from RB administration until the maximum blocking of T1 by TOF stimulation was measured. RESULTS: There was no significant difference in escape behaviors of vascular pain among the three groups, and the onset time of muscle relaxation was significantly slower in Group 3 than in Group 1 (p = 0.033). CONCLUSION: Our results suggested that it is unnecessary to dilute RB before administration if a large vein in the forearm is used. TRIAL REGISTRATION: UMINCTR Registration number UMIN000026737 . Registered 29 Mar 2017.

The usefulness of the McGrath MAC laryngoscope in comparison with Airwayscope and Macintosh laryngoscope during routine nasotracheal intubation: a randomaized controlled trial.

BACKGROUND: McGrath MAC video laryngoscope offers excellent laryngosopic views and increases the success rate of orotracheal intubation in some cases. The aim of this study was to determine the usefulness of McGrath MAC for routine nasotracheal intubation by comparing McGrath MAC with Airway scope and Macintosh laryngoscope. METHODS: A total of 60 adult patients with ASA physical status class 1 or 2, aged 20-70 years were enrolled in this study. Patients were scheduled for elective oral surgery under general anesthesia with nasotracheal intubation. Exclusion criteria included lack of consent and expected difficult airway. Patients were randomly allocated to three groups: McGrath MAC (n = 20), Airway scope (n = 20), and Macintosh laryngoscope (n = 20). After induction, nasotracheal intubation was performed by six expert anesthesiologists with more than 6 years of experience. RESULTS: There were no significant differences in preoperative airway assessment among the three groups. Successful tracheal intubation time was 26.8 ± 5.7 (mean ± standard deviation) s for McGrath MAC, 36.4 ± 11.0 s for Airway scope, and 36.5 ± 8.9 s for Macintosh laryngoscope groups. The time for successful tracheal intubation for McGrath MAC group was significantly shorter than that for Airway scope and Macintosh laryngoscope (p < 0.01). McGrath MAC significantly improved the Cormack Lehane grade for nasotracheal intubation compared with Macintosh laryngoscope (p < 0.05). CONCLUSION: McGrath MAC significantly facilitates routine nasotracheal intubation compared with Airwayscope and Macintosh laryngoscope by shortening the tracheal intubation time and improving the Cormack Lehane grade. TRIAL REGISTRATION: UMINCTR Registration number UMIN000023506 . Registered 5 Aug 2016.

The effectiveness of a mouth guard to protect against strong occlusion caused by modified electroconvulsive therapy.

Modified electroconvulsive therapy (m-ECT) is a treatment for mental disease such as depressive disorder. Although a muscle relaxant is used during current application, strong occlusion occurs due to the proximity of the electrode to the temporal and masseter muscles. Although a feedback mechanism to avoid excessive occlusion occurs unconsciously, the mechanism does not work under general anesthesia. Strong occlusion may cause complications such as tooth injury, pain of the jaw, lip laceration, and bleeding of the gums. Although there was a report that the insertion of shock-absorbing materials such as gauze reduces complications, there has been no study on the effectiveness of a mouth guard (MG) for alleviating the occlusal force during m-ECT. The present study investigated the effectiveness of MG for alleviation of the occlusal force and complications during m-ECT. An ethyl-vinyl-acetate (EVA) MG was used as a shock absorbing material to mitigate the strong occlusion during m-ECT to investigate the influence of MG on the occlusal force and its effectiveness. The results showed that the occlusal force was alleviated by 58 ± 22% on average using MG during m-ECT. It also helped reduce intra-oral problems such as pain and bleeding. The results suggest the effectiveness of MG for alleviating the occlusal force during m-ECT and avoiding complications due to strong occlusion.

The effect of sevoflurane on developing A/J strain mouse embryos using a whole-embryo culture system--the incidence of cleft lip in culture embryos.

A/J strain mice have a high spontaneous incidence of cleft lip (ICL) and/or palate. The primary palate-related effects of sevoflurane on developing A/J strain mouse embryos (embryos) were studied using a whole-embryo culture (WEC) system. This system could separate the direct effects of sevoflurane from those that are maternally mediated. A total of 205 10.5-d embryos were cultured for 24 h in either a control group (control gas: 95% O2 and 5% CO2) or sevoflurane-administered groups (1/4, 1/2, and 1 minimum alveolar concentration (MAC) with control gas) for 8 h. After 16 h, 11.5-d culture embryos were examined in terms of crown-rump length, number of somites, and protein content. Crown-rump length in the 1 MAC was significantly shorter than in the control group (p < 0.05). Protein content in the 1/2 MAC (p < 0.05) and 1 MAC (p < 0.001) was significantly lower than in the control group. The ICL showed no significant differences between each group. (The ICL rose with an increase in the sevoflurane concentration, but this was not significant). The positive findings in this study indicate that a WEC system is useful for studying the mechanisms of ICL (teratogenicity) associated with sevoflurane.