A Novel Case Report of Iatrogenic Tracheal Rupture Caused by a Laser-Resistant Endotracheal Tube Under Transoral Laser Laryngeal and Nasopharyngeal Surgery.

BACKGROUND Intraoperative tracheal rupture due to endotracheal intubation is a rare but serious complication that requires prompt responses. Transoral laser microsurgery is effective for dissection of laryngeal and nasopharyngeal lesions, and a laser-resistant endotracheal tube is therefore commonly used under general anesthesia. CASE REPORT We present the case of a 69-year-old man in whom a rare complication involving endotracheal tube tip dislodgement during transoral laser surgery led to iatrogenic tracheal rupture. We used a Laser-Flex cuffed endotracheal tube, which is a non-inflammable, armored stainless-steel tube with a Murphy eye. Repeated mobilization of the laryngoscope blade and excessive neck extension for adequate laryngeal exposure during surgery may have led to significant soft tissue swelling and tube tip displacement, inducing tracheal rupture with the keen edge of the Murphy eye. At the end of the surgical procedure, subcutaneous emphysema was observed in the right anterior neck. Computed tomography revealed subcutaneous emphysema and pneumomediastinum without esophageal injury or mediastinitis. The injury was 1 cm in length, with wall involvement to a depth to the muscular wall in the membranous trachea at a point 2 cm proximal to the carina, in which we could position the alternative endotracheal tube distal to the tracheal rupture. After conservative treatment, the patient was extubated and mechanical ventilation was ceased. CONCLUSIONS During transoral laser laryngeal and nasopharyngeal surgery, dislodgement of the laser-resistant endotracheal tube tip can lead to iatrogenic tracheal rupture. In this case, injury during application of a Laser-Flex cuffed endotracheal tube with a Murphy eye, was followed by conservative treatment. This treatment achieved a successful outcome.

Two-handed facemask technique effectively causes hyperventilation in electroconvulsive therapy: an observational study.

BACKGROUND: Electroconvulsive therapy (ECT) remains the mainstay treatment option for patients with psychiatric diseases, such as severe depression. Although various anesthetic techniques provide adequate therapeutic seizures, hyperventilation is a useful adjunct to augment seizure duration and improve seizure quality. We investigated how to efficiently use a facemask to accomplish protocolized hyperventilation and evaluate its effect on ECT seizure. METHODS: We studied 60 patients aged ≥18 years who underwent ECT. The patients were divided into two groups according to the technique of facemask ventilation used: the one-handed (n = 30) and two-handed (n = 30) groups. Following anesthesia induction under preoxygenation conditions, hyperventilation induced hypocapnia in the one-handed facemask group with manual bag ventilation was compared to that in the two-handed facemask group with assisted pressure-controlled ventilation. Ictal and peri-ictal electroencephalogram parameters and cardiovascular responses were monitored and compared between the one-handed and two-handed groups. RESULTS: The two-handed technique demonstrated better electroencephalogram regularity and minimized cardiovascular stress compared to the one-handed technique. These conclusions come from the fact that the one-handed technique induced a substantial volume of leaks around the facemask (201.7 ± 98.6 mL/breath), whereas minimal leaks (25.8 ± 44.6 mL/breath) with stabler and higher ventilation rate led to greater inhaled minute ventilation in the two-handed group (the one-handed group, 9.52 ± 3.94 L/min; the two-handed group, 11.95 ± 2.29 L/min; p <  0.005). At the end of ECT treatment, all parameters of blood pressure and heart rate increased significantly in both groups equally, with lower SpO2 and more ST-segment depression on the electrocardiogram in the one-handed group. Comparing baseline values before anesthesia, ECT treatment significantly depressed ST-segment in both groups, while the degree of depression in ST-segment increased significantly in the one-handed group compared to that in the two-handed group. CONCLUSIONS: End-tidal carbon dioxide monitoring for hyperventilation can reliably ensure hypocapnia only in the two-handed group. In ECT, the two-handed technique assisted by pressure-controlled ventilation is an effective and practical method for hyperventilation to induce adequate therapeutic seizures. While, the two-handed group with sufficient preoxygenation did not cause more cardiovascular stress than the one-handed group. TRIAL REGISTRATION: UMIN Clinical Trials Registry 000046544, Date of registration 05/01/2022.

Factors affecting prolonged time to extubation in patients given remimazolam.

PURPOSE: To analyze the cause of prolonged recovery from general anesthesia with remimazolam. METHODS: We studied 65 patients under general anesthesia with remimazolam. According to time to extubation, patients were divided into short period (SP) (n = 34, < 15 min) and long period (LP) (n = 31, ≥ 15 min) groups. Variables affecting time to extubation such as age, sex, height, body weight, body mass index (BMI), plasma albumin concentration, ASA class, duration of surgery, and total duration of general anesthesia, and total dose of remimazolam were compared between SP and LP groups. At the end of remimazolam infusion and upon extubation, predictive remimazolam concentrations were calculated using pharmacokinetic/pharmacodynamic three compartment modeling. RESULTS: LP group showed significantly higher BMI, older age, and lower plasma albumin concentration compared with those of SP group. Logistic regression analysis showed that the probability of time to extubation of ≥ 15 min was higher in patients with BMI greater than 22.0 kg/m2 (AUC 0.668, 95% CI 0.533‒0.803), ages older than 79.0 years (AUC 0.662, 95% CI 0.526‒0.798), and plasma albumin concentrations lower than 3.60 g/dl (AUC 0.720, 95% CI 0.593‒0.847). LP group showed significantly lower predicted remimazolam concentration than SP group upon extubation despite no difference in concentration between both groups at the end of infusion. Pharmacological analysis estimates that LP group is more sensitive to remimazolam than SP group through amplified responses. CONCLUSIONS: Lower remimazolam doses should be considered for the overweight patients, elderly, and those with lower plasma albumin concentration.

[Fibrin-related Markers in Acute Phase of Pulmonary Embolism and Deep Venous Thrombosis].

BACKGROUND: The fibrin-related markers are considered to be useful in diagnosing pulmonary embolism (PE) and deep vein thrombus (DVT). We measured D-dimer (DD) and soluble fibrin monomer complex (SFMC) in these cases, in order to examine the usefulness of these markers. METHODS: PE patients (P group: 14 cases) and DVT patients (D group : 16 cases) treated in our hospital, were examined. We measured the value of DD and SFMC on the first visit day and the second day. In PE cases, comparative examination of the markers were carried out between dead and survived cases. RESULTS: The value of both markers in P group ware significantly higher compared with D group, on the second day. There was a significant correlation between SFMC and DD in P group, but in D group, significant correlation was not observed. CONCLUSIONS: It seems that measuring DD and SFMC is useful to evaluate the pathology of PE and DVT.

[The Efficacy of Soluble Fibrin Monomer Complex (SFMC) for Diagnosis of Aortic Dissection (AD)].

BACKGROUND: Some biomarkers are helpful for AD diagnosis. Although many studies on efficacy of D-dimer have been reported, there are few reports about SFMC. Therefore we conducted a retrospective comparative study of efficacy of SFMC and D-dimer for diagnosis of AD. METHODS: Nineteen patients diagnosed as AD in the emergency visit were examined. Patients with cardiopulmonary arrest on arrival were excluded. These patients were classified into three patterns as follows, Stanford A or B, terms of arriving at hospital, and closing type or patent type. The value of D-dimer and SFMC were measured at the time of the first medical examination, and comparative study of both biomarkers was carried out in each groups. RESULTS: Background of patients were not significantly different in three studies. SFMC and D-dimer showed no significant difference between Stanford A and B. Short-terms SFMC is significantly higher than long-terms. But D-dimer showed no significant difference in each comparison. Patent type of SFMC showed higher than closing type. But D-dimer showed no significant difference between patent type and closing type. CONCLUSIONS: SFMC showed earlier response to AD than D-dimer. Measuring SFMC coupled with D-dimer is helpful for AD diagnosis.

[Use of i-gel supraglottic airway for emergency airway management by novice personnel in comparison with laryngeal mask airway and tracheal intubation in manikin models].

BACKGROUND: Tracheal intubation (TI) is a difficult skill to acquire and its proficiency deteriorates over time if not regularly practiced. However, inexperienced personnel may be required to perform airway management in emergency situations. We compared a novel supraglottic device, i-gel, with laryngeal mask airway classic (cLMA) and TI devices in regard to total success count, time required for placement, and difficulties encountered by novice personnel using a manikin model. METHODS: Following a brief training, 24 residents were asked to insert each of i-gel, cLMA, and TI in a randomize fasion using a manikin. Success counts for placement and time required to chest rise were recorded. After completing the tests, the participants scored the difficulty of each device using a visual ana-log scale (0-100 mm, very easy to very difficult). RESULTS: The total success count with i-gel (46 times) was significantly higher than those of both cLMA (32 times) and TI (38 times), and the time to chest rise with i-gel (14 +/- 6 seconds) was significantly shorter than with cLMA (38 +/- 26 seconds). The difficulty score for i-gel (12 [0-51] mm) was significantly lower than those for both cLMA (51 [0-94] mm) and TI (25 [0-73] mm). CONCLUSIONS: An i-gel may be useful for emergency airway management by inexperienced personnel. Further studies in a clinical setting are necessary to confirm these findings.

[Adverse events during transcranial muscle evoked potential monitoring].

BACKGROUND: Transcranial muscle evoked potential (TC-MsEP) monitoring is available to assess spinal cord motor tract function for preventing paralysis in spine surgery. Recently, the quality of monitoring has improved. However, adverse events such as torn tracheal tube, bitten tongue, and mandibular fracture are reported. METHODS: We reviewed retrospectively adverse events with TC-MsEP monitoring by Multipulse D-185 (Digitimer Ltd., the U.K.) during spine surgery in our hospital. In addition, we compared the number of cases with transformed tracheal tubes in cases using Multipulse D-185 and in cases using the other stimulation device. RESULTS: Since June 2007, Multipulse D-185 is applied as a stimulating device of TC-MsEP, and we experienced two adverse events of lasceration of tongue and teeth dislocation. There was a significant difference (P=0.02) in the number of transformed tracheal tube between Multipulse D-185 (11 of 20) and the other stimulation device (2 of 19). CONCLUSIONS: It seems that two adverse events were due to excessive masseter muscles contraction with TC-MsEP monitoring. Prevention for bite injury and ventilation strategy for tube occlusion or stenosis using Multipulse D-185 for TC-MsEP are necessary.

[Anesthetic management of a patient with erythropoietic protoporphyria for laparoscopic appendectomy].

Porphyria is a hereditary disorder due to reduction in enzyme activity of heme synthesis system, resulting in accumulation of heme precursors. Erythropoietic protoporphyria (EPP) is a type of porphyria. There are varieties of clinical expressions of EPP such as hepatic damage and photosensitivity, caused by the accumulation of protoporphyrin in the liver and the skin. Therefore it is important to prevent development of these clinical expressions. A 36-year-old woman with EPP was scheduled for a laparoscopic appendectomy. Anesthesia was induced with remifentanil, sevoflurane and rocuronium, and maintained with remifentanil, fentanyl and sevoflurane. She had performed normal daily activities without taking countermeasures against photosensitivity, so we did not change the light in the operating room, and allowed using endoscopy. The surgery was performed without any complications. No skin symptom was observed perioperatively. The level of aminotransferase was elevated temporally after the operation, while the level of protoporphyrin was unchanged. Therefore, we considered there was no manifestation of EPP perioperatively. In general, patients with EPP do not develop acute attacks induced by drugs like barbiturates. Since there was a case report of severe liver dysfunction of EPP, we did not use any contraindicated drugs in patients with acute intermittent porphyria in this patient. Considering a possibility of motor nerve damage in severe EPP, we carried out anesthetic management without epidural anesthesia.