Less postoperative sore throat after nasotracheal intubation using a fiberoptic bronchoscope than using a Macintosh laryngoscope: A double-blind, randomized, controlled study.

STUDY OBJECTIVE: To evaluate whether nasotracheal intubation using a fiberoptic bronchoscope reduces postoperative sore throat. DESIGN: Prospective, double-blinded, randomized, and controlled study. SETTING: Postoperative areas and surgical ward of a university hospital. PATIENTS: Seventy-four patients with American Society of Anesthesiologists physical status I-II who were scheduled for elective general anesthesia requiring nasotracheal intubation. INTERVENTIONS: Patients were randomized to one of two intubation groups, F (fiberoptic bronchoscope-guided) and M (Macintosh laryngoscope-guided), and after induction of general anesthesia, the patients' tracheas were intubated via the nose. MEASUREMENTS: The intensity of postoperative sore throat was evaluated using a numerical rating score (0=none, 10=severe) at 24 hours postoperatively, and the incidence of nasal mucosal trauma, time to completion of intubation, and hemodynamic responses were recorded and compared between groups. MAIN RESULTS: The numerical rating score value was significantly lower in group F than in group M (P=.0047), but the incidence of nasal mucosal trauma was comparable between the two groups. The median time to completion of intubation was shorter for group F than group M (P<.0001). Hemodynamic responses were not significantly different. CONCLUSIONS: Fiberoptic bronchoscope-guided intubation is associated with less sore throat after nasotracheal intubation than M intubation. The time to completion of intubation was significantly shorter using the fiberoptic bronchoscope than that using the Macintosh laryngoscope.

Incidence of cannot intubate-cannot ventilate (CICV): results of a 3-year retrospective multicenter clinical study in a network of university hospitals.

PURPOSE: The purpose of this study was to investigate the incidence of cannot intubate-cannot ventilate (CICV) during general anesthesia during a 3-year period in a network of university hospitals and to evaluate the events related to it. METHODS: A retrospective multicenter questionnaire survey of CICV, based on medical record review, was conducted over a 3-year period (January 2010-December 2012) in Hokkaido, Japan. All cases were assessed in terms of the suspected risk factors of CICV, the clinical course during anesthesia, and the prognosis. RESULTS: Responses were obtained from 20 of 21 institutions (95%) surveyed. The incidence of CICV was 3 of 97,854 cases conducted under general anesthesia (0.003%). All incidents occurred during induction of general anesthesia. In two of the three cases, difficult airway was predicted preoperatively. In all these three cases, mask ventilation became impossible after repeated intubation attempts with devices such as the Macintosh laryngoscope, the Airwayscope, or a fiberoptic bronchoscope. A laryngeal mask was inserted in one case, but the lungs could not be adequately ventilated. Emergency tracheotomy was eventually performed in all the CICV cases. Although two of the patients did not have postoperative neurological sequelae, severe and permanent brain damage occurred in one patient. CONCLUSION: In our survey, we found that the incidence of CICV during a 3-year period (2010-2012) was 0.003% or 1 in 32,000 cases. The three CICV situations occurred after repeated intubation attempts with multiple devices. The appropriate airway devices to be used in a particular difficult airway situation should be carefully considered before performing multiple attempts.

Evaluation of bias in predicted and measured propofol concentrations during target-controlled infusions in obese Japanese patients: an open-label comparative study.

BACKGROUND: Target-controlled infusions (TCIs) of propofol are commonly used for general anaesthesia. The Marsh model pharmacokinetic parameter set incorporated in TCI devices for propofol could increase bias when used in obese patients. OBJECTIVE: The purpose of this study was to assess the optimal predicted blood concentration (Cp) of 4.0 µg ml of propofol using a correction formula including BMI and to evaluate the influences on propofol concentration in obese patients. DESIGN: An open-label, comparative study. SETTING: Sapporo Medical University Hospital, Japan, from October 2011 to December 2013. PATIENTS: Seventy-five adults scheduled for elective surgery under general anaesthesia with the following exclusion criteria: less than 30 or more than 65 years of age; American Society of Anesthesiologists status 3 to 5; allergy to propofol; the daily use of psychoactive drugs; known or suspected drug or alcohol abuse; and cardiac, hepatic, renal or neurological impairment. INTERVENTION: Propofol was administered and maintained at a Cp of 4.0 µg ml using a TCI device programmed with the Marsh pharmacokinetic model. Arterial blood samples were collected at 15, 30, 60, 90, 120, 150 and 180 min after the start of the infusion, and the measured propofol concentration (Cm) was determined. After calculation of the adjustment formula using the corrected Cp of 69 patients, we then applied the corrected Cp to five other obese patients. MAIN OUTCOME MEASURES: The median performance error (MDPE) and median absolute performance error (MDAPE) were calculated to measure bias at each time point. RESULTS: We analysed 333 samples from the 69 individuals. There was a significant correlation between BMI and Cm, which tended be greater than 4.0 µg ml in obese patients. Our new method improved MDPE and MDAPE from a range of 20 to 40 for both, to ranges of -11.3 to -1.8 and 8.8 to 11.5, respectively. CONCLUSION: BMI influences blood propofol concentrations, leading to the possibility of overdosage of propofol in obese patients when the Marsh model is used to assess propofol concentration. Our new method using corrected Cp might improve this bias in obese, Japanese patients.

[Anesthetic management in a patient with spinal progressive muscle atrophy and compromised severe restrictive respiratory dysfunction].

Spinal progressive muscular atrophy (SPMA) is a rare lower motor neuron disease in which anesthetic management is often difficult as a result of muscle weakness and hypersensitivity to neuromuscular blocking agents. A 43-year-old female patient with SPMA was scheduled to undergo laparotomy for ovarian teratoma. Her vital capacity was only 530 ml and % volume capacity was 22.2%, indicating a severe restrictive pulmonary disfunction. We selected general and epidural anesthesia for the surgery. Anesthesia was induced by propofol and the trachea was intubated with additional topical anesthesia. Spontaneous ventilation was kept during anesthesia without neuromuscular blocking agents, and systemic and epidural opioids were avoided to evade their respiratory depression. Because of severe spine scoliosis syndrome, we inserted an epidural catheter into the epidural space under radiographic monitoring for safety and precision. Postoperative pain control was stable using continuous epidural infusion of 0.2% ropivacaine without neurological adverse effects. One day after surgery, the trachea was extubated and respiratory function did not aggravate. Despite the controversy surrounding the use of neuraxial blocks in motor neuron diseases, in this case, epidural anesthesia was useful to keep the respiratory function stable.

Utility of longitudinal paramedian view of ultrasound imaging for middle thoracic epidural anesthesia in children.

PURPOSE: The risk of nerve injury for pediatric thoracic epidural block increases stress for anesthesiologists. The purpose of this study was to investigate the usefulness of longitudinal ultrasound imaging for thoracic epidural block (T5-T6 or T6-T7) in anesthetized children scheduled for the Nuss procedure. METHODS: Neuraxial structure in the longitudinal paramedian section was observed using ultrasound imaging before epidural puncture (US group, n = 10). In the control group, usual epidural block without ultrasound was performed. Attempts were made to observe epidural catheterization in ultrasound imaging in three cases. RESULTS: Patient age ranged from 5 to 7 years. Time for epidural block in the US group [100 (77-116) s; median value (95% confidence interval)] was significantly shorter than that in the control group [165 (130-206) s; P = 0.001]. The difficulty score was significantly lower in the US group than in the control group (P < 0.001). Epidural catheterization was observed in all three cases in which the catheter manipulated the dura mater ventrally. There was a high correlation (r = 0.98, P < 0.001) between needle depth and ultrasound estimation of the skin-dura distance in the US group. CONCLUSION: We concluded that longitudinal paramedian ultrasound imaging could reduce performance time and the difficulty for anesthesiologists during epidural block.

Ultrasound-guided cervical nerve root block: spread of solution and clinical effect.

OBJECTIVES: We investigated the clinical effects and accuracy of ultrasound-guided cervical nerve root block. Additionally, spinal level and spread of injected solution were confirmed by anatomic dissection of fresh cadavers. DESIGN SETTING, PATIENTS, AND INTERVENTIONS: Twelve patients diagnosed with mono-radiculopathy between C5-7 underwent ultrasound-guided nerve root block. An insulated needle was advanced with an in-plane approach using nerve stimulation and 2 mL of 0.375% ropivacaine with 4 mg of dexamethasone was injected using nerve stimulation. Ultrasound-guided C5-7 nerve root block was also performed in ten fresh cadavers. Blue dye (2 mL) was injected onto each nerve root and anatomic dissection was performed to confirm the exact spinal level and spread pattern of the dye. RESULTS: Pain score before the procedure (65 [46-80], median [interquartile range]) was decreased to 25 [3-31] at 24 hours (P = 0.003) and 40 [28-66] at 30 days (P = 0.02) after the root block. Obvious side effects were not seen. All target nerve roots in patients and cadavers were correctly identified by ultrasound imaging. The needle tip did not reach the pedicle of the vertebral arch in the anteroposterior view of fluoroscopy, and spread pattern of contrast medium was extraforaminal and extraneural. CONCLUSIONS: This study suggests that injected solution by ultrasound-guided cervical nerve root block mainly spreads to the extraforaminal direction compared with conventional fluoroscopic technique. Therefore, present clinical study involves possibility of safer selective nerve root block with sufficient analgesic effects by ultrasound guidance, despite the absence of intraforaminal epidural spread of solution.

Usefulness of Endoflex endotracheal tube for oral and nasal tracheal intubations.

BACKGROUND AND OBJECTIVES: We investigated the usefulness of an Endoflex tracheal tube, the tip of which can be bent forward by pulling on a wire held in the hand, for oral and nasal endotracheal intubations without a stylet, in comparison with tracheal intubation using a conventional endotracheal tube and a stylet/Magill forceps. METHODS: The study participants comprised 40 patients for oral intubation and 20 patients for nasal intubation. Each group was then divided into control and Endoflex subgroups. In the oral intubation study, controls were intubated using a standard Macintosh-type laryngoscope with a conventional endotracheal tube with adjuvant use of a stylet, whereas the Endoflex group was intubated using a Macintosh-type laryngoscope with an Endoflex tube. In the nasal intubation study, controls were intubated by a standard Macintosh-type laryngoscope with an endotracheal tube for nasal intubation. Under direct vision, Magill forceps were used to guide the tip of the endotracheal tube into the glottis. Patients in the Endoflex group were intubated using a Macintosh-type laryngoscope with an Endoflex tube. RESULTS: Although haemodynamic changes during tracheal intubation did not differ between the groups, the duration of intubation was significantly shortened in the Endoflex groups in both studies. CONCLUSION: The Endoflex endotracheal tube represents a beneficial tool for smooth oral and nasal intubation without requiring assistance or adjuvant equipment.