Comparison of the tidal volume by the recruitment maneuver combined with positive end-expiratory pressure for mechanically ventilated children

The recruitment maneuver (RM) combined with PEEP to prevent atelectasis have beneficial effects. However, the change in tidal volume (VT) due to RM combined with PEEP in pediatric patients during the induction of general anesthesia is unknown. Therefore, we assessed the effects of RM combined with PEEP on VT. Pediatric patients were divided into three groups: infants, preschool children, and school children. The RM was performed by maintaining pressure control continuous mandatory ventilation (PC-CMV) with a 15 cmH2O and PEEP increase of 5 cmH2O. VT, respiratory function and hemodynamics were monitored before and after RM combined with PEEP. VT (mL) /ideal body weight (kg) before vs. after RM combined with PEEP were 9 vs 12 mL/kg (p < 0.05) in the infants, 9 vs 11 mL/kg (p < 0.05) in the preschool children, 8 vs 10 mL/kg (p < 0.05) in the school children, respectively. HR and BP before and after RM combined with PEEP increased by 2-3% and decreased by 4-7% in all groups. RM combined with PEEP resulted in an increase in VT per ideal body weight (1.1-1.2%). Therefore, this RM combined with PEEP method might improve the lung function in pediatric patients.

Positional Change Used to Manage Postextubation Respiratory Failure in a Child With Cerebral Palsy

Dental treatment for patients with cerebral palsy (CP) is often performed under general anesthesia due to involuntary movements that can render dental treatment difficult. Since CP is often accompanied by spasticity, care must be taken when positioning patients during general anesthesia. We report the management of a 14-year-old girl with CP and epilepsy undergoing general anesthesia for dental treatment who experienced respiratory failure due to acute thoracoabdominal muscle hypertonia after extubation. She had a history of cardiac arrest due to respiratory failure caused by acute muscle hypertonia and successful resuscitation. General anesthesia was induced after careful positioning of the patient to prevent spastic muscle stretching, and the dental treatment was completed without complications. However, upon awakening after extubation, the patient developed respiratory failure due to acute muscle hypertonia. The patient was resedated and repositioned from a supine to a sitting position, and her symptoms improved. There was no recurrence of muscle hypertonia, and she recovered fully without complications. In this case, respiratory failure associated with acute muscle hypertonia was successfully managed by position change after initial treatment with positive-pressure ventilation and propofol. It is important to be prepared for the possibility of respiratory failure associated with acute muscle hypertonia and its countermeasures when providing general anesthesia for patients with CP.

The difference in rotation angle of the distal endotracheal tube through nasal approach

BACKGROUND

Nasal intubation using a fiberoptic scope is a useful technique. In clinical practice, we have experienced difficulty in advancing the endotracheal tube (ETT) over the fiberoptic scope because of resistance to the passage of the ETT against rotation in the nasal cavity, when it gets hung up on structures of the laryngeal inlet. Several maneuvers have been proposed to overcome this difficulty. The gap between the tip of the ETT and the fiberoptic scope can be reduced using a thicker fiberoptic scope and a thinner ETT. Moreover, simultaneous rotation of the fiberoptic scope and ETT could lead to successful intubation by reducing impingement on the ETT. However, the discrepancy between these rotation angles is unclear. This observational prospective study aimed to investigate the discrepancy in the rotation angle between the ETT and fiberoptic scope during nasal intubation.

METHODS

The patients (aged 20-80 years) who underwent nasal intubation for oral and maxillofacial surgery participated in three sizes of preformed nasal ETT and were intubated using a fiberoptic scope. They were divided into three groups; the ETT internal diameter (ID) 6.5 mm (6.5 group), ID 7.0 mm (7.0 group), and ID 7.5 mm (7.5 group). The ETT was then inserted through the nasal cavity into the pharynx. After the fiberoptic scope was advanced through the ETT above the glottis, simultaneous rotation by both the proximal end of the fiberoptic scope and ETT was performed in 90° and 180° in both right (clockwise) and left (counterclockwise) directions, and the rotation angle at the distal end of the ETT was monitored using a video laryngoscope (Pentax-AWS).

RESULTS

A total of 39 patients were included in the study. When both the proximal end of the fiberscope and ETT were simultaneously rotated by 90°, in the 6.5 group (n = 13), the distal end of the ETT rotated by 47.8 ± 1.5°. In the 7.0 °group (n = 13), the distal end of the ETT rotated by 45.5 ± 1.0°. In the 7.5 group (n = 13), the distal end of the ETT rotated by 39.9 ± 1.0°. When the proximal end of the fiberscope and ETT were rotated by 180°, in the 6.5 group, the distal end of the ETT rotated by 166.2 ± 2.5°. In the 7.0 group, the distal end of the ETT rotated by 145.7 ± 2.2°. In the 7.5 group, the distal end of the ETT rotated by 115.1 ± 2.0°. All rotation angles in the distal end of the ETT were significantly lower than those in both the proximal end of the fiberscope and ETT (p < 0.05). Rotating right by 180° was significantly different among the three groups (p < 0.05), although rotating right by 90° was not significantly different. Similar results were obtained for the left rotation.

CONCLUSION

Simultaneous rotation by the proximal end of the ETT and fiberscope above the glottis for the nasal approach induced significant differences in the distal end of the ETT. The larger tube lagged by the resistance of the nasal passages during rotation. Therefore, the ETT does not rotate as much as the rotation angle.

TRIAL REGISTRATION

This prospective observational study was conducted after receiving approval from the Ethics Review Board of Kyushu University Hospital (Approval No. 30-447).

Comparison of different methods of more effective chest compressions during cardiopulmonary resuscitation (CPR) in the dental chair

Introduction

When performing cardiopulmonary resuscitation (CPR) on a patient who has suffered a cardiopulmonary arrest during dental treatment, few dental chairs have sufficient stability to perform effective chest compressions. We previously proposed a method of stabilizing the backrest of a dental chair using a support stool. As a result, we confirmed that the vertical displacement of the backrest could be significantly reduced. In the present study, we verified the effectiveness of the stool stabilization method using several dental chairs (flat and curved) with significantly different backrest shapes.

Methods

Vertical displacement of the backrests of dental chairs was recorded. Data were obtained at three different stool positions (without a stool, under the chest at the level that participants were performing manual chest compressions, and under the shoulders). Reduction displacement ratios were calculated to evaluate the effectiveness of the stool positions.

Results

The method significantly reduced the vertical displacement of the backrest for all types. When the curvature of the backrest was large, the reduction in vertical displacement was 40% when the stool was placed under the chest at the level of manual chest compressions and 65% when placed underneath the shoulder. In the case of a flat dental chair, this reduction was 90% when using a stool in either position, compared to no stool.

Conclusion

When we need to perform CPR on a patient in the dental chair, placing a stool under the shoulders allows effective manual chest compression by firmly supporting the backrest of a dental chair of any shape.

A Comparison of Two Stool Positions for Stabilizing a Dental Chair During CPR

OBJECTIVE

Most dental chairs lack sufficient stability to perform effective manual chest compression (MCC) during cardiopulmonary resuscitation (CPR). A stabilizing stool can significantly reduce backrest vertical displacement in all chair types; however, a severely curved exterior backrest may negatively impact the stool's effectiveness. This study evaluated the efficacy of 2 stool positions for stabilizing a dental chair during MCC.

METHODS

Chest compressions were performed on a manikin positioned in a dental chair while vertical displacement of the chair backrest during MCC was recorded using video and measured. Vertical displacement data were captured with no stool and with a stabilizing stool in 2 different positions. Reduction ratios were calculated to evaluate the effectiveness of the 2 stool positions.

RESULTS

With no stool, the backrest median (interquartile range) vertical displacement during chest compressions was 16.5 (2.5) mm as compared with 12.0 (1.5) mm for the stabilizing stool positioned under the area of MCC and 8.5 (1.0) mm under the shoulders. The stool positioned under the shoulders produced a significantly increased calculated reduction ratio of 48% (14%) compared with 27% (20%) under the area of MCC (P < .001).

CONCLUSIONS

Positioning a stabilizing stool under the shoulders was more effective at reducing vertical displacement of the dental chair backrest during chest compressions than positioning the stool under the area of MCC.

Alternative Technique for Nasotracheal Intubation Using a Flexible Fiberoptic Scope

In oral maxillofacial surgery, the endotracheal tube (ETT) is often inserted nasotracheally to provide surgeons a better view and easier access to the oral cavity. Use of a flexible fiberoptic scope is an effective technique for difficult intubation. While the airway anatomy can be observed as the scope is advanced, the ETT tip cannot be observed with the traditional method. It is occasionally difficult to advance the ETT beyond the glottis as impingement of the ETT tip may occur. We devised a new nasotracheal intubation technique using a fiberoptic scope. In this novel technique, the ETT and fiberoptic scope are inserted into the pharyngeal space separately through the right and left nasal cavities. This permits continuous observation of the glottis as the ETT is advanced into the trachea. The main advantage of this technique is that the ETT tip is visualized as it is advanced, which helps avoid impingement of the ETT. If resistance is noted, the ETT can easily be rotated or withdrawn without causing laryngeal damage, leading to safe and smooth intubation. This novel technique allows advancement of the ETT under continuous indirect vision, thus minimizing contact of the ETT with the laryngeal structures and aiding in unhindered passage into the glottis.

Sevoflurane concentration for cannulation in developmental disabilities

Objective

The goal of this study was to compare the end-tidal sevoflurane concentration and time for intravenous cannulation at induction of anesthesia using sevoflurane with or without nitrous oxide in healthy children and in those with developmental disabilities.

Methods

Normal and developmentally disabled children were anesthetized by inhalation of sevoflurane with nitrous oxide or with nitrous oxide-free oxygen, and intravenous cannulae were introduced. Nitrous oxide was stopped after loss of consciousness. The following parameters were recorded for each patient: age, gender, height, weight, BMI, duration of intravenous cannulation, end-tidal concentration of sevoflurane at the completion of intravenous cannulation, and use of nitrous oxide.

For each parameter except gender, p-value were calculated by one-way analysis of variance (ANOVA). For gender, p-value were calculated using the Fisher method. Two-way ANOVA was performed to evaluate the effect of patient health status and nitrous oxide use on the end-tidal concentrations of sevoflurane and the time required for intravenous cannulation.

Results

The end-tidal sevoflurane concentrations at the completion of the intravenous cannulation had received a significant main effect of the factor "the use of nitrous oxide" (F(1,166) = 25.8, p < 0.001, η² = 0.13) and a small effect of the factor "the patient health status" (F(1,166) = 0.259, p = 0.611, η² = 0.001). However, the time required for intravenous cannulation was not significantly affected by either of the two factors, "the use of nitrous oxide" (F(1,166) = 0.454, p = 0.501, η² = 0.003) and "the patient health status" (F(1,166) = 0.308, p = 0.579, η² = 0.002).

Conclusions

Between the healthy children and the children with developmental disabilities, no significant differences in the time required for the intravenous cannulation from the beginning of anesthetic induction. However, the end-tidal sevoflurane concentrations at the completion of the intravenous cannulation was significantly different. Sevoflurane in alveoli might be diluted by nitrous oxide.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12871-022-01695-5.

Risk Factors for Postoperative Sore Throat After Nasotracheal Intubation

OBJECTIVE

Postoperative sore throat is relatively frequent complication after orotracheal intubation. However, there are few reports about postoperative sore throat in nasotracheal intubation. In this retrospective study, we investigated the risk factors of postoperative sore throat in nasotracheal intubation.

METHODS

Anesthesia records of patients 16 to 80 years of age who underwent nasotracheal intubation were included. Patients underwent oral and maxillofacial surgery from February 2015 until September 2018. Airway device (Macintosh laryngoscope, Pentax-AWS, or McGRATH video laryngoscope, or fiberoptic scope), sex, age, height, weight, American Society of Anesthesiologists classification, intubation attempts, duration of intubation, intubation time, tube size, and fentanyl and remifentanil dose were investigated. Fisher exact test, Wilcoxon rank sum test, Welch t test, and Steel-Dwass multiple test were used, and a multivariable analysis was performed using stepwise logistic regression to determine the risk factors of postoperative sore throat.

RESULTS

A total of 169 cases were analyzed, and 126 patients (74.6%) had a postoperative sore throat. Based on the univariate analysis of the data, 12 factors were determined to be potentially related to the occurrence of a postoperative sore throat. However, after evaluation using stepwise logistic regression analysis, the 2 remaining variables that correlated with postoperative sore throat were airway device (P &lt; .05) and intubation attempts (P = .04). In the model using logistic regression analysis, the fiberoptic scope had the strongest influence on the incidence of sore throat with reference to Pentax-AWS (odds ratio = 5.25; 95% CI = 1.54-17.92; P &lt; .05).

CONCLUSION

Use of a fiberoptic scope was identified as an independent risk factor for postoperative throat discomfort. Compared with direct laryngoscopy and other video laryngoscopes, the use of a fiberoptic scope had a significantly higher incidence of sore throat.

A Case of Laryngeal Granulomas After Oral and Maxillofacial Surgery With Prolonged Intubation

Laryngeal granuloma development can be a postoperative complication of laryngeal trauma or irritation resulting from general anesthesia and endotracheal intubation. These rare benign lesions are located primarily over the cartilaginous portions of the larynx, particularly the vocal processes of the arytenoids. Airway manipulation during the intubation process and prolonged intubation periods can be contributing factors to intubation-related laryngeal granulomas, which may manifest 1 to 4 months after intubation. The patient in this case was a female who returned with complaints of throat pain without hoarseness or sensations of a "lump in her throat" 3 months following surgery, during which she was intubated with a 7.0-mm nasotracheal tube for 30 hours, likely contributing to her bilateral laryngeal granulomas. The patient underwent successful conservative medical management consisting of a proton pump inhibitor and an inhaled corticosteroid.

Cleft-lip-plate patient with tracheobronchomalacia: A case report and review of the literature in Japan

Background

Tracheobronchomalacia (TBM) is a severe life-threatening perioperative complication. It is a rare condition caused by congenital and developmental anomalies of the trachea and/or the bronchus. It is often difficult to diagnose TBM before surgery as this congenital disease presents very few symptoms preoperatively and most often appears postoperatively.

Case presentation and Review

The study describes a case of cleft-lip-plate (CL/P) in a 7-month-old Japanese female with TBM and Tetralogy of Fallot syndrome. Before undergoing cleft-lip surgery, her TBM was not fully elucidated by preoperative examinations, and the operation was completed uneventfully. After the surgery, however, she started showing severe respiratory distress and developed hypoxia and bradycardia in the operating room. CPR was performed successfully, but a bronchoscopy revealed a severely collapsed airway, and the pathological condition was diagnosed as TBM occurred postoperatively. Eight months later, she died of sudden respiratory failure similar to that of the postoperative event caused by TBM. A literature review was conducted on the complications of CL/P from 1990 to 2017 in Japan.

Conclusions

It was hypothesized that CL/P with congenital heart disease (CHD) and TBM with CHD may crossover in relatively high rates. Currently, there are very few solutions available to treat severe airway obstruction related to TBM. This highlights the need for preoperative diagnosis of TBM as an important step in overcoming severe airway complications.

Mask Induction for an Intellectually Disabled Patient With Congenital Infiltrating Lipomatosis of the Face

Airway management for patients with craniofacial disorders poses many challenges. Congenital infiltrating lipomatosis of the face (CILF) is an extremely rare disorder in which mature lipocytes invade adjacent tissues in the head and neck. The manifestations are typically unilateral, often with associated hypertrophy of both the hard and soft tissues of the face. This is a case report regarding the anesthetic management for a 5-year-old intellectually disabled female with CILF involving the right side of her face who underwent a successful intubated general anesthetic for dental treatment. Awake fiber-optic intubations are recommended and routinely used for patients with suspected or confirmed difficult airways. In this case, substantial distortion of the normal facial anatomy was observed clinically with noted hypertrophy of the right maxilla, mandible, and right side of the tongue. Further complicating matters was the patient's inability to fully cooperate because of her intellectual disability, precluding the option of an awake fiber-optic intubation. To secure the airway following mask induction of anesthesia, spontaneous ventilation was carefully maintained using sevoflurane, nitrous oxide, and oxygen combined with the application of a nasopharyngeal airway. Despite compression of the oral cavity and upper pharyngeal space by the hypertrophic tissues due to CILF, the space in and around the glottis was preserved. Intubation was completed easily with the use of a fiber-optic scope without any serious complications.

Influence of measurement principle on total hemoglobin value

Background

Total hemoglobin (tHb) measurement is indispensable for determining the patient’s condition (hemorrhagic vs. ischemic) and need for blood transfusion. Conductivity- and absorbance-based measurement methods are used for blood gas analysis of tHb. For conductivity-based measurement, tHb is calculated after converting blood conductivity into a hematocrit value, whereas absorbance measurement is based on light absorbance after red blood cell hemolysis. Due to changes in plasma electrolytes and hemolysis, there is a possibility that conductivity- and absorbance-based measurement methods may cause a difference in tHb.

Methods

In this study, test samples with controlled electrolyte changes and hemolysis were created by adding sodium chloride, distilled water or hemolytic blood to blood samples collected from healthy volunteers, and tHb values were compared between both methods.

Results

Conductivity-based measurement revealed reduced tHb value (from 15.49 to 13.05 g/dl) following the addition of 10% sodium chloride, which was also reduced by the addition of hemolysate. Conversely, the addition of distilled water significantly increased tHb value than the expected value. In the absorbance method, there was no significant change in tHb value due to electrolyte change or hemolysis.

Conclusions

We have to recognize unexpected conductivity changes occur at all times when tHb is measured via conductivity- and absorbance-based measurement methods. The absorbance method should be used when measuring tHb in patients with expected blood conductivity changes. However, when using this method, the added contribution of hemoglobin from hemolytic erythrocytes lacking oxygen carrying capacity must be considered. We recognize that discrepancy can occur between conductivity- and absorbance-based measurement methods when tHb is measured.

Endotracheal Tube Migration Associated With Extension During Tracheotomy

Tracheotomy is occasionally performed to prevent postoperative airway obstruction especially for invasive surgical procedures involving head and neck cancer. When performed under general anesthesia, attention must be paid to avoid rupture of the tracheal tube cuff during the incision into the trachea. In this study, changes in the position of the endotracheal tube tip during extension of the head and neck for a tracheotomy were investigated. Twelve patients underwent placement of a tracheotomy during surgical procedures for oral cancer. After nasal intubation, the distance between the tube tip and the carina was measuring using a fiberoptic scope with the patient's head placed at an angle of 110°. Patients were repositioned for tracheotomy by placing a pillow under the shoulders and extending the head and neck at an angle of 140°. The distance measurements were subsequently repeated. The difference between the first and second measurements was calculated and analyzed statistically using a paired t test. On average the patients were 69.5 ± 9.0 years in age. The distance between the tube tip and the carina at an angle of 140° (3.6 ± 1.1 cm) was significantly longer than that at an angle of 110° (1.7 ± 1.0 cm) (p < 0.001). The migration in the positioning of the endotracheal tube tip was 1.9 ± 0.7 cm (range: 0.7-3.7 cm) upon extension. In 3 cases, the tube cuff was ruptured during incision of the trachea. The endotracheal tube tip may migrate in the cephalad direction approximately 2 cm as a result of the extension of the patient's head and neck during a tracheotomy. Therefore, consideration should be given to advancing the endotracheal tube tip towards the caudal side and to confirming the position of the tube and cuff during a tracheotomy.

Comparison of the Performance of Mask Ventilation Between Face Masks With and Without Air Cushion

PURPOSE

Mask ventilation is a basic technique for induction of anesthesia. In head and neck surgery, we have encountered difficulty in ventilation owing to facial deformities. Recently, a new type of face mask without an air cushion, the QuadraLite face mask (Intersurgical, Berkshire, UK), was developed. The aim of this study was to compare the performance of cases with predicted difficult mask ventilation between the new type of face mask and a traditional face mask.

PATIENTS AND METHODS

This study was a crossover prospective study. The participants were patients (aged > 18 years) who underwent oral-maxillofacial surgery under general anesthesia. The risk factors for a difficult airway were assessed. Patients were divided into 3 risk groups: low risk, 0 or 1 risk factor for predicted difficult mask ventilation; medium risk, 2 or 3 risk factors; and high risk, 4 or more risk factors. An air cushion face mask (Koo Medical, Shanghai, China) and the QuadraLite face mask were applied in turn under the setting of pressure-controlled ventilation. The expiratory tidal volumes were compared between these face masks.

RESULTS

A total of 48 patients were included: 16 in the low-risk group, 16 in the medium-risk group, and 16 in the high-risk group. Higher expiratory tidal volumes were observed with the QuadraLite face mask than with the air cushion face mask, although the differences did not reach the statistically significant level: 574.3 ± 62.7 mL versus 553.1 ± 60.6 mL in the low-risk group (P = .44), 553.1 ± 112.9 mL versus 536.4 ± 114.2 mL in the medium-risk group (P = .38), and 560.0 ± 98.6 mL versus 548.2 ± 07.1 mL in the high-risk group (P = .22). In all cases, a sufficient ventilation volume was obtained by the QuadraLite face mask.

CONCLUSIONS

The QuadraLite face mask is compact because there is no air cushion, and it can provide sufficient mask ventilation as well as a traditional face mask with an air cushion even in patients with a difficult airway.

Usefulness of a stool to stabilize dental chairs for cardiopulmonary resuscitation (CPR)

Background

Cardiopulmonary resuscitation (CPR) requires immediate start of manual chest compression (MCC) and defibrillation as soon as possible. During dental surgery, CPR could be started in the dental chair considering difficulty to move the patient from the dental chair to the floor. However, all types of dental chairs are not stable for MCC. We previously developed a procedure to stabilize a dental chair by using a stool. EUROPEAN RESUSCITATION COUNCIL (ERC) guideline 2015 adopted our procedure when cardiac arrest during dental surgery. The objective of this study was to verify the efficacy of a stool as a stabilizer in different types of dental chairs.

Methods

Three health care providers participated in this study, and 8 kinds of dental chairs were examined. MCC were performed on a manikin that was laid on the backrest of a dental chair. A stool was placed under the backrest to stabilize the dental chair. The vertical displacement of the backrest by MCC was recorded by a camcorder and measured by millimeter. Next, the vertical displacement of the backrest by MCC were compared between with and without a stool.

Results

In all 8 dental chairs, the method by using a stool significantly reduced the vertical displacements of the backrest by during MCC. The reduction ratio (mean [interquartile range]) varied between nearly 27 [20] and 87 [5] %. In the largest stabilization case, the displacement was 3.5 [0.5] mm with a stool versus 26 [5.5] mm without a stool (p <  0.001).

Conclusions

Our procedure to stabilize dental chairs by using a stool reduced the displacement of a backrest against MCC in all chairs.

Clinical relevance

Effective MCC could be performed in dental chairs by using a stool when sudden cardiac arrest occurs during dental surgery.

Changes in nasotracheal tube depth in response to head and neck movement in children

BACKGROUND

A tracheal tube is often inserted via the nasal cavity for dental surgery. The position of the tube tip is important, given that the head position sometimes changes during surgery. Head movement induces changes in the length of the trachea (t-length) and/or the distance between the nare and the vocal cords (n-v-distance). In this study, we investigated the changes in t-length and n-v-distance in children undergoing nasotracheal intubation.

METHODS

Eighty patients aged 2-8 year undergoing dental surgery were enrolled. After nasotracheal intubation with an uncuffed nasotracheal tube (4.5-6.0 mm), the tube was fixed at the patient's nares. The distance between the tube tip and the first carina was measured using a fibrescope with the angle between the Frankfort plane and horizontal plane set at 110°. The location of the tube in relation to the vocal cords was then checked. These measurements were repeated at angles of 80° (flexion) and 130° (extension). The t-length and n-v-distance were then calculated using these measurements.

RESULTS

On flexion, the t-length shortened significantly from 87.5 ± 10.4 mm to 82.9 ± 10.7 mm (P = 0.017) and the n-v-distance decreased from 128.1 ± 10.7 mm to 125.6 ± 10.4 mm (P = 0.294). On extension, the t-length increased significantly from 87.5 ± 10.4 mm to 92.7 ± 10.1 mm (P = 0.007) and the n-v-distance increased from 128.1 ± 10.7 mm to 129.4 ± 10.7 mm (P = 0.729). The change in t-length was significantly greater than that in the n-v-distance.

CONCLUSION

A change in the position of the tracheal tube tip in the trachea depends mainly on changes in t-length during paediatric dental surgery.

Awake fiberoptic nasotracheal intubation for patients with difficult airway

Awake fiberoptic nasotracheal intubation is a useful technique, especially in patients with airway obstruction. It must not only provide sufficient anesthesia, but also maintain spontaneous breathing. We introduce a method to achieve this using a small dose of fentanyl and midazolam in combination with topical anesthesia. The cases of 2 patients (1 male, 1 female) who underwent oral maxillofacial surgery are reported. They received 50 µg of fentanyl 2-3 times (total 2.2-2.3 µg/kg) at intervals of approximately 2 min. Oxygen was administered via a mask at 6 L/min, and 0.5 mg of midazolam was administered 1-4 times (total 0.02-0.05 mg/kg) at intervals of approximately 2 min. A tracheal tube was inserted through the nasal cavity after topical anesthesia was applied to the epiglottis, vocal cords, and into the trachea through the fiberscope channel. All patients were successfully intubated. This is a useful and safe method for awake fiberoptic nasotracheal intubation.

Influence of Fasting Duration on Body Fluid and Hemodynamics

Fasting before general anesthesia aims to reduce the volume and acidity of stomach contents, which reduces the risk of regurgitation and aspiration. Prolonged fasting for many hours prior to surgery could lead to unstable hemodynamics, however. Therefore, preoperative oral intake of clear fluids 2 hours prior to surgery is recommended to decrease dehydration without an increase in aspiration risk. In this study, we investigated the body fluid composition and hemodynamics of patients undergoing general anesthesia as the first case of the day versus the second subsequent case. We retrospectively reviewed the general anesthesia records of patients over 20 years old who underwent oral maxillofacial surgery. We investigated patient demographics, preoperative fasting time, anesthetic time, urine output, infusion volume, and opioid and vasopressor use. With respect to body fluid and hemodynamics, we extracted the data from the induction of anesthesia through 2 hours of anesthesia time. Thirty patients were suitable for this study. Patients were divided into 2 groups: patients who underwent surgery as the first case of the day (am group: n = 15) and patients who underwent surgery as the second case (pm group: n = 15). There were no significant differences between the 2 groups in patient demographics. In the pm group, fasting time for a light meal (832 minutes) was significantly longer than for the am group (685 minutes), p = .005. In the pm group, fasting time for clear fluids (216 minutes) was also significantly longer than for the am group (194 minutes), p = .005. Body fluid composition was not significantly different between the 2 groups. In addition, cardiac parameters intraoperatively were stable. In the pm group, vasopressors were used in 4 patients at the induction of anesthesia (p = .01). There were not statistically significant changes in cardiac function or body fluid composition between patients treated as the first case of the day vs patients who underwent surgery with general anesthesia as the second case of the day.

Airway Management for a Pediatric Patient With a Tracheal Bronchus

Tracheal bronchus is an ectopic bronchus almost arising from the right side of the tracheal wall above the carina. The incidence of a tracheal bronchus is reported as 0.1 to 3%. We experienced a patient with tracheal bronchus that was incidentally found at induction of anesthesia. Endotracheal intubation in a patient with tracheal bronchus might cause obstruction of the tracheal bronchus, although in this case, ventilation was not impaired.

Body composition and hemodynamic changes in patients with special needs

Background

Some patients with special needs exhibit intellectual disability, including deficits in cognitive skills and decreased quality of life. The purpose of this study was to retrospectively compare changes in body composition and hemodynamics during general anesthesia in patients with and without special needs.

Methods

The backgrounds of patients who underwent oral maxillofacial surgery under general anesthesia were recorded from medical records. Intracellular water (ICW), extracellular water (ECW), stroke volume variation (SVV), and heart rate (HR) were recorded for 3 h after the start of anesthesia. Categorical data were compared using an unpaired t-test, and a P-value of less than 0.05 was regarded as significant. Numerical data were compared using the Bonferroni correction, and a P-value of less than 0.0125 was regarded as significant.

Results

A total of 21 patients were included in the study: 10 patients without special needs (non-S-group) and 11 patients with special needs (S-group). There were no significant differences in patients' backgrounds, except with regard to height (P = 0.03). In both groups, ICW and ECW were maintained, although they were lower in the S-group compared to the non-S-group. SVV was maintained in both groups, although it was higher in the S-group than the non-S-group. HR was significantly lower in the S-group 1 h after induction of anesthesia (P < 0.003).

Conclusions

Changes in hemodynamics due to body fluid imbalance should be monitored during general anesthesia, especially for patients with special needs.

Flexible laryngeal mask airway management for dental treatment cases associated with difficult intubation

Nasotracheal intubation is generally a useful maxillofacial surgery that provides good surgical access for intraoral procedures. When nasotracheal intubation is difficult, laryngeal mask airway (LMA) insertion can be performed, and the flexible LMA™ (FLMA) is also useful for anesthetic management. However, the FLMA provides limited access to the mouth, which restricts the insertion of instrumentation and confines the surgical field available. Here, we present our experience using the FLMA airway management for dental treatment cases involving difficulty with intubation.

The Anesthetic Management for a Patient With Trisomy 13

Trisomy 13 is a chromosomal disorder that occurs in complete or partial mosaic forms. It is characterized by central apnea, mental retardation, seizure and congenital heart disease. The survival of the patients with trisomy 13 is the majority dying before one month. Trisomy 13 is the worst life prognosis among all trisomy syndromes. It is reported the cause of death is central apnea. Special needs patients with mental retardation are recognized to have poorer oral health condition. Oral health related quality of life reflects daily activity and well-being. Dental treatment under general anesthesia is sometimes an option for such patients. This patient had received ventricular septal defect closure surgery at 2-year-old. In addition, he had mental retardation and seizure. Dental treatment had been completed without any cerebral and cardiovascular events under non-invasive monitoring with not only cardiac electric velocimetry, but also epileptogenic activity. In addition, postoperative respiratory condition was maintained stable in room air.

Analysis of Preoperative Airway Examination with the CMOS Video Rhino-laryngoscope

BACKGROUND

Endoscopy is one of the most useful clinical techniques in difficult airway management Comparing with the fibroptic endoscope, this compact device is easy to operate and can provide the clear image. In this study, we investigated its usefulness in the preoperative examination of endoscopy.

METHODS

Patients undergoing oral maxillofacial surgery were enrolled in this study. We performed preoperative airway examination by electronic endoscope (The CMOS video rhino-laryngoscope, KARL STORZ Endoscopy Japan, Tokyo). The system is composed of a videoendoscope, a compact video processor and a video recorder. In addition, the endoscope has a small color charge coupled device (CMOS) chip built into the tip of the endoscope. The outer diameter of the tip of this scope is 3.7 mm.

RESULTS

In this study, electronic endoscope was used for preoperative airway examination in 7 patients. The preoperative airway examination with electronic endoscope was performed successfully in all the patients except one patient The patient had the symptoms such as nausea and vomiting at the examination.

CONCLUSIONS

We could perform preoperative airway examination with excellent visualization and convenient recording of video sequence images with the CMOS video rhino-laryngoscope. It might be a especially useful device for the patients of difficult airways.

Anesthetic Management for Twice in a Child with Klippel-Feil Syndrome

Klippel-Feil syndrome (KFS) is a complex syndrome of osseous and visceral anomalies that include the classical clinical triad of short neck, limitation of head and neck movement and low posterior hairline. It may also be associated with anomalies of the genitourinary, musculoskeletal, neurologic and cardiac systems. We experienced surgery for a case of KFS complicated with cleft palate and ankyloglossia. This boy underwent palatoplasty with a push-back method at 19 months of age, and frenumectomy at 31 months. respectively. We had to secure the field of operation and airway management involved difficult tracheal intubation. Careful postoperative care and respiratory management are also required for the patient afflicted with KFS.

[Anesthetic Management of a Patient with Pulmonary Atresia and Intact Ventricular Septum Accompanying Sinusoidal Communication]

We experienced a case of a patient with pulmonary atresia and intact ventricular septum (PAIVS) accompanying sinusoidal communication. PAIVS can be associated with coronary artery anomalies, including sinu- soidal communications from the right ventricle to coronary. In addition, the coronary circulation depends on the blood supply from the right ventricle. The patient was a 1-year-old boy with PAIVS (9.0 kg in weight and 74 cm in height). He had undergone balloon atrial septostomy, central shunt and Glenn procedure. Preopera- tive percutaneous oxygen saturation was 85% which decreased to 80% with agitation. He was scheduled for cheiloplasty. The goals of anesthetic management for the patient were to maintain a decrease in pulmonary vascular resistance and an increase in pulmonary blood flow to sinusoidal communications. Stable Pa0₂ was maintained by adjusting FI0₂ : 0.5, and Paco₂ : 30-35 mmHg. Hemodynamics was maintained by fluid trans- fusion, maintaining urine volume and α₁-adrenoceptor agonist We used Aesculon® for monitoring cardiac output which is a noninvasive cardiac function monitor based on impedance technology.

[Anesthetic Management of a Patient with Rett Syndrome Presenting Severe Breath Holding and Massive Aerophagia]

We anesthetized a patient with Rett syndrome pre- senting intense breath holdings and severe aerophagia for dental treatment The patient had shown an intense breath holding plunging into hypoxia during slow induction with sevoflurane in previous anesthesias. Therefore, we chose rapid sequence induction with intravenous propofol and rocuronium and intubated orally. The length of glottis to tracheal bifurcation was shorter than average patient After a gastric tube was inserted and the content was aspirated, the orotracheal tube was changed to nasotracheal one. When she recovered from anesthesia at the quite deep stage, her saliva poured from nose and orally and began severe aerophagia. Once again, deep depth of anesthesia was kept, and we minimized stimulations for her. By. this approach, anesthesia was achieved uneventfully. In this case, she had signs of early-awakening from anesthesia.

Low-dose carperitide (α-human A-type natriuretic peptide) alleviates hemoglobin concentration decrease during prolonged oral surgery: a randomized controlled study

PURPOSE

Surgical injury stimulates the renin-angiotensin-aldosterone system (RAAS) and causes antidiuresis, leading to postoperative oliguria. Carperitide (α-human A-type natriuretic peptide) is a cardiac peptide hormone secreted from the atrium. This peptide hormone enhances diuresis by suppressing the RAAS. In our experience, carperitide alleviates decreased hemoglobin (Hb) concentration during elective surgery. In the current study, we investigated the relationship between low-dose carperitide (0.01 µg/kg/min) and Hb concentration during oral surgery.

METHODS

Patients (ASA-PS: I-II, 40-80 years old) undergoing oral maxillofacial surgery (duration of operation >8 h) were enrolled in this study. Patients were divided into two groups: the carperitide group received carperitide at 0.01 µg/kg/min and the control group received normal saline. Body fluid water [including total body water (TBW), extracellular water (ECW), and intracellular water (ICW)], urine volume, and chemical parameters such as Hb concentration, PaO₂, and serum electrolytes were evaluated every 2 h.

RESULTS

In the carperitide group (n = 15), Hb decreased from 12.6 ± 1.1 to 10.8 ± 1.5 g/dl, while it decreased from 12.6 ± 1.4 to 9.5 ± 1.3 g/dl in the control group (n = 15) (p < 0.05). Urine volume (2557.3 ± 983.5 mL) in the carperitide group was significantly more than it was in the control group (1108.8 ± 586.4 mL; p < 0.001). There were no significant differences in clinical characteristics, body fluid water, PaO₂, and serum electrolytes between the two groups. In addition, there were no perioperative clinical respiratory and hemodynamic complications in the groups.

CONCLUSION

The Hb concentration in the group administered low-dose carperitide at 0.01 µg/kg/min remained higher than that in the control group during surgery. Administration of low-dose carperitide may therefore reduce the risk of blood transfusion during surgery.

Influence of the marvelous™ three-way stopcock on the natural frequency and damping coefficient in blood pressure transducer kits

Two types of Planecta™ ports are commonly used as sampling ports in blood pressure transducer kits: a flat-type port (FTP) and a port with a three-way stopcock (PTS). Recently, a new type of three-way stopcock (Marvelous™) has been released as a Planecta™ counterpart, but its effects on the frequency characteristics and reliability of blood pressure monitoring have not been investigated. We assessed the influence of the Marvelous™ stopcock on the frequency characteristics of the pressure transducer kit. The basic pressure transducer kit, DT4812J, was modified by replacing one or two of the original three-way stopcocks with Marvelous™ stopcocks. The frequency characteristics (i.e., natural frequency and damping coefficient) of each kit were determined using wave parameter analysis software, and subsequently evaluated on a Gardner chart. Replacement of the original blood pressure transducer kit stopcocks with Marvelous™ stopcocks decreased the natural frequency (48.3 Hz) to 46.3 Hz or 44.8 Hz, respectively; the damping coefficient was not significantly changed. Plotting the data on a Gardner chart revealed that the changes fell within the adequate dynamic response region, indicating they were within the allowable range. Insertion of Marvelous™ stopcocks slightly affects the natural frequency of the pressure transducer kit, similar to inserting a PTS. The results indicate that the Marvelous™ stopcock is useful for accurate monitoring of arterial blood pressure, and may be recommended when insertion of two or more closed-loop blood sampling systems is necessary.

Perioperative airway management of a patient with Beckwith-Wiedemann syndrome

Airway obstruction in pediatric patients always poses a challenge for anesthesiologists. Beckwith-Wiedemann syndrome causes various abnormalities such as macroglossia and omphalocele. Patients with these abnormalities often need corrective surgeries. Management of difficult airway caused by conditions such as macroglossia in patients with this syndrome could be challenging. We encountered a case of difficult airway in an infant with Beckwith-Wiedemann syndrome. It was predicted that macroglossia might cause difficult ventilation, intubation, and extubation. Preoperative assessment and preparations for difficult airway should be considered.

Discrepancy between electroencephalography and hemodynamics in a patient with Cockayne syndrome during general anesthesia

Cockayne syndrome is a kind of progeria with autosomal chromosome recessiveness described first by Cockayne in 1936. Patients with this syndrome were characterized by retarded growth, cerebral atrophy, and mental retardation. We experienced an anesthetic management of a patient with Cockayne syndrome, who underwent dental treatment twice. The primary concern was discrepancy between electroencephalography and hemodynamics. The values of bispectral index showed a sharp fall to 1 digit and suppression ratio more than 40, while hemodynamics was stable during induction of anesthesia with sevoflurane 8%. We should pay attention to anesthetic depth in the central nervous system in patients with Cockayne syndrome. Titration of anesthetics should be performed by the information from electroencephalography.

Risk Factors for Postoperative Shivering After Oral and Maxillofacial Surgery

PURPOSE

Postoperative shivering is a frequent complication of anesthesia. However, there are few reports about postoperative shivering in oral and maxillofacial surgery. Postoperative shivering in patients after osteotomy was observed from April 2008 to September 2015. This retrospective study investigated the risk factors of postoperative shivering in oral and maxillofacial surgery.

PATIENTS AND METHODS

Anesthesia records of patients who underwent an osteotomy of the maxilla or mandible were checked. A patient's background (gender, age, height, and weight), anesthesia time, operative time, fentanyl, remifentanil, fluid volume, urine volume, blood loss volume, agent for anesthetic maintenance, rectal temperature at the end of surgery, and type of surgery were recorded in addition to the occurrence of postoperative shivering. In the univariate analysis, the Fisher exact test and the χ² test were used, and a multivariable analysis was performed using stepwise logistic regression to determine risk factors of postoperative shivering.

RESULTS

In this study, 233 cases were investigated, and 24 patients (11.5%) had postoperative shivering. The occurrence of postoperative shivering was correlated with blood loss volume (shivering group, 633.9 ± 404.8 mL; nonshivering group, 367.0 ± 312.6 mL; P < .01) and core temperature at the end of surgery (shivering group, 37.2 ± 0.6°C; nonshivering group, 37.5 ± 0.5°C; P < .01). Two variables were associated with postoperative shivering. Rectal temperature at the end of surgery was the highest risk factor (odds ratio = 2.560277; 95% confidence interval, 1.236774-5.327362), and blood loss volume was the next highest risk factor (odds ratio = 0.997733; 95% confidence interval, 0.999-0998).

CONCLUSION

Clinicians should pay attention to postoperative shivering not only in patients with hypothermia but also in patients with substantial blood loss.

[Perioperative Management of a Child with Vocal Adhesion Leading to Unexpected Difficult Airway]

We report a child with vocal cord adhesion encountered during induction of anesthesia. A 4-month-old girl was scheduled for bilateral lip plasty. She was intubated for one week due to pneumonia at the age of 3 days. Hoarseness and stridor appeared just after extubation. Although laryngo-fiberoptic examination had been tried several times, otorhinologists could not find any abnormality. We once decided to postpone the operation because of severe stridor. However, laryngofiberoptic examination could not reveal any abnormality, and we rescheduled the operation. Tracheal intubation using laryngoscope was not possible due to vocal cord adhesion. Finally, 2.5 mm ID tracheal tube was intubated by using a fiberscope, and lip plasty was performed. The patient stayed in the ICU for 7 days after surgery. Tracheotomy was performed 3 weeks after the operation. We should pay attention to stridor in an infant before general anesthesia, since it suggests severe airway narrowing although laryngo-fiberoptic examination could not find any abnormalities.

[Anesthesia Management of a Patient with Pulmonary Atresia, Intact Ventricular Septum, Major Aortopulmonary Collateral Artery and Tetralogy of Fallot]

The patient was a 6-year-old girl with pulmonary atresia, intact ventricular septum and major aortopulmonary collateral artery with tetralogy of Fallot Her Sp(O2) was around 60% under room air, and she could not walk long. She underwent dental treatment under general anesthesia. Invasive monitoring using pulmonary artery catheter should have been avoided, since the risk of monitoring greatly exceeds that of the treatment. The patient entered the operating room with her mother, and anesthesia was induced with intravenous midazolam, propofol and vecuronium. She was intubated orally first and impedance cardiography monitoring was started. FI(O2) was maintained at 0.5-1.0. Increases in airway pressure and Pa(CO2) were appropriately avoided. Dental treatment is important for infants with cardiac disease not only to reduce their pain, but also to reduce the risk of infection. It often requires general anesthesia. We have to conduct it with less invasiveness and less stress.

[Intravenous Sedation and Repeated "the Same Day General Anesthesia" for a School-age Boy with Dandy-Walker Syndrome and Dentinogenesis]

Dandy-Walker syndrome (DWS) is characterized by perfect or partial defect of the cerebellum vermis and cystic dilatation of the posterior fossa communicating with the fourth ventricle. Common clinical signs are mental retardation, cerebellar ataxia, and those of increased intracranial pressure (ICP). Associated congenital anomalies are craniofacial, cardiac, renal, and skeletal abnormalities. We experienced a case of intravenous sedation and six times of "the same day" general anesthesia for a school-aged boy (10-13 years old) with DWS and hypodentinogenesis. The patient underwent an examination and dental treatments. We had to pay attention to airway management tracheal tube selection and control of ICP. In addition, we should prevent tooth injuries through mishaps during tracheal intubations, since all-tooth-hypoplasia with fragile dental crowns was strongly suggested in this case. Detailed postoperative care is also required for general anesthesia afflicted with DWS.

Anesthetic Management of a Patient With Emanuel Syndrome

Emanuel syndrome is associated with supernumerary chromosome, which consists of the extra genetic material from chromosome 11 and 22. The frequency of this syndrome has been reported as 1 in 110,000. It is a rare anomaly associated with multiple systemic malformations such as micrognathia and congenital heart disease. In addition, patients with Emanuel syndrome may have seizure disorders. We experienced anesthetic management of a patient with Emanuel syndrome who underwent palatoplasty. This patient had received tracheotomy due to micrognathia. In addition, he had atrial septal defect, mild pulmonary artery stenosis, and cleft palate. Palatoplasty was performed without any complication during anesthesia. Close attention was directed to cardiac function, seizure, and airway management.

[Repeated Anesthesia Management in a Patient with Aicardi Syndrome]

Aicardi syndrome is a rare hereditary disorder that develops in only girls with the trilogy of nutatory epilepsy, callosal agenesis and chorioretinopathy. We experienced general anesthesia twice for a patient with Aicardi syndrome in addition to heavy mental retardation. She underwent surgical correction for cleft lip and palate at 6 months of age and at 2 years of age, respectively. Anesthesia was induced slowly with inhalation of nitrous oxide, oxygen and sevoflurare. After securing an intravenous route, midazolam, thiopental and vecuronium were administered and intubated orally. Anesthesia was maintained with isoflurane safely. Patients with Aicardi syndrome have a high risk of aspiration pneumonia caused by underdeveloped swallowing ability due to callosal agenesis. We should, therefore, pay attention to prevention of seizure and aspiration pneumonia during the perioperative period.

Impact of lithium-ion ordering on surface electronic states of Li(x)CoO2

Li(x)CoO(2) exhibits intriguing electronic properties due to a strong electron correlation and complex interplay between Co and Li ions. However, fundamental understanding of the nanoscale distribution of Li ions and its effect on the electronic properties remains unclear. We use scanning tunneling microscopy and density functional theory to elucidate the degree of Li(x)CoO(2) surface electronic state modification that can be achieved by Li ordering. The surface Li ions are highly mobile and preferentially form a (1 × 1) hexagonal lattice, whereas the surface CoO(2) layer shows metallic and insulating phases, indicating the coexistence of ordered and disordered Li ions in the subsurface layer. These results provide evidence of novel electronic properties produced by spatially inhomogeneous Li-ordering patterns.

Hydroxyethyl Starch: The Effect of Molecular Weight and Degree of Substitution on Intravascular Retention In Vivo

BACKGROUND

Hydroxyethyl starch (HES) solution is characterized by its mean molecular weight (MW), concentration, and degree of substitution (DS). This character varies worldwide.

METHODS

After binding fluorescein-isothiocyanate (FITC-HES), we evaluated the retention rate of three types of 6% HES in the A2 and V2 blood vessels of rat cremaster muscles using intravital microscopy in a mild hemorrhage model (10% of total blood volume). After blood withdrawal, we infused three types of FITC-HES: HES-A (MW 150-200 kDa, DS 0.6-0.68), HES-B (MW 175-225 kDa, DS 0.45-0.55), or HES-C (MW 550-850 kDa, DS 0.7-0.8) before determining the FITC-HES retention rate in the intravital microscope.

RESULTS

For V2, the FITC-HES retention rates 120 min after the start of the infusion were 27% +/- 7.2% of baseline values (HES-A), 65% +/- 9.1% (HES-B), and 86% +/- 9.6% (HES-C); for A2 they were 27% +/- 6.6%, 73% +/- 10.2%, and 89% +/- 8.7%, respectively. HES-B and HES-C were retained in the vessels longer than HES-A (P = 0.028 for V2, P = 0.038 for A2 between HES-B and HES-A; P = 0.022 for V2, P = 0.037 for A2 between HES-C and HES-A). There was no difference in the rate of disappearance from the vessels between HES-B and HES-C.

CONCLUSIONS

HES-B and HES-C are equally retained in the blood vessels. Middle-sized HES-B with low DS and middle substitution pattern stayed in the blood vessels as long as the large-sized HES. HES solutions of varying characters should be examined to optimize HES infusion.

Three cases of retroesophageal right subclavian artery

We have experienced three cases of retroesophageal right subclavian artery. Two cases were cadavers, and one case was a live human. In the two cadavers of a 68-year-old and a 76-year-old, respectively Japanese and European males, the right subclavian artery originated from the aorta after the aorta branched the right carotid artery, the left carotid artery and the left subclavian artery. The right carotid artery immerged solely from the aorta. Where the right subclavian artery originated from the aorta, the artery took a dorsal direction. It passed between the esophagus and the vertebral column. The esophagus was compressed from the dorsal side by the right subclavian artery. The structural anomaly of the right subclavian artery accompanied the cephalad recurrence of the branch from the right vagal nerve toward the larynx. In the live human case, we obtained CT views. The patient was a 41-year-old Japanese, who complained of dysphagia lusoria. We found that the right subclavian artery was anomalous and originated from the aorta as the last cardinal branch in the thorax.

Dopant-pair structures segregated on a hydrogen-terminated Si(100) surface

Novel atomic structures on a H-terminated Si(100)-(2x1)-H surface were found using scanning tunneling microscopy (STM). The structures are distinguishable only from Si dimers in empty-state STM images. They were observed on arsenic- and phosphorus-doped substrates, but not on boron-doped substrates. Surface density of these structures was found to be proportional to the dopant density in the substrate. First-principles calculations clarify that they are consisting of dopant pairs that are segregated from the bulk material. Hydrogen atoms attached to the dopant pair are found to flip between two positions on the surface due to a quantum effect.