Jong-Man Kang

An estimation of right- and left-sided central venous catheter insertion depth using measurement of surface landmarks along the course of central veins.

BACKGROUND: In this study we sought to determine whether the topographical measurement along the course of the central veins can estimate the approximate insertion depths of central venous catheters (CVC). METHODS: Two hundred central venous catheterizations were performed via the right and left internal jugular vein (IJV) or subclavian vein (SCV). The anterior approach, using the sternocleidomastoid muscle as a landmark, was used for IJV catheterization and the infraclavicular approach for SCV. Topographical measurement was performed by placing the catheter with its own curvature over the draped skin starting from the insertion point of the needle through the ipsilateral clavicular notch, and to the insertion point of the second right costal cartilage to the manubriosternal joint. The CVC was inserted and secured to a depth determined topographically. The distance between the CVC tip and the carina and the angle of the left-sided CVC tip to the vertical were measured on the postoperative chest radiograph. RESULTS: The mean (SD) tip position of 50 CVCs placed via the right IJV was 0.1 (1.1) cm above the carina; right SCV, 0.0 (0.9) cm; left IJV, 0.3 (1.0) cm above the carina, and left SCV, 0.2 (0.9) cm below the carina. CVC locations could be predicted with a margin of error between 2.2 cm below the carina and 2.3 cm above the carina in 95% of patients. There were steeper (≥40°) angles to the vertical in the left-sided CVCs whose tips were above the carina (17 out of 54) than below the carina (2 out of 46). CONCLUSIONS: The approximate insertion depth of a CVC can be estimated using measurement of surface landmarks along the pathway of central veins.

Delayed preconditioning effect of isoflurane on spinal cord ischemia in rats

Paraplegia is one of the most common complications following aortic aneurysmal surgery. This study was designed to determine if isoflurane-induced delayed preconditioning is mediated by nuclear factor kappaB (NF-kappaB) in the rat spinal cord. The animals were divided into four groups: the control group, the pyrrolidinedithio carbamate (PDTC, an NF-kappaB inhibitor)-treated group, the isoflurane-treated group, and the PDTC/isoflurane-treated group. In the PDTC-treated groups, 2% 100mg/kg PDTC was administered intraperitoneally at 1h before operation and at 24h and 48 h after reperfusion. The rats in the isoflurane-treated groups received 30 min inhalation of 2.8% isoflurane at 24h before spinal cord ischemia. Pretreatment with NF-kappaB inhibitor significantly reduced NF-kappaB expression and the number of intact motor neurons when compared to the control group. Preconditioning with isoflurane increased the number of normal motor neurons, whereas pretreatment with both PDTC and isoflurane significantly decreased them, compared to the isoflurane-treated group. Isoflurane-induced delayed preconditioning on spinal cord ischemia improved histopathological outcomes. This neuroprotective effect of isoflurane preconditioning on spinal cord ischemia is associated with NF-kappaB expression.

Bedside Prediction of Airway Length in Adults and Children

Background:Malpositioning of the endotracheal tube within the airway leads to serious complications such as endobronchial intubation. Prediction of the correct depth of an endotracheal tube is important and should be individualized. The manubriosternal joint (MSJ) is on the same horizontal plane with the tracheal carina. We compared the straight length from the upper incisor to the MSJ in the fully extended position (incisor-MSJ extension length) with the length from the upper incisor to the carina after intubation with a flexible fiberoptic bronchoscope through the endotracheal tube in the neutral position (incisor-carina neutral length). Methods:One hundred adults and 50 children were studied. Induction of anesthesia was achieved with 1.5 mg/kg propofol and 0.6 mg/kg rocuronium IV. The incisor-MSJ extension length was measured after adequate mask ventilation. After intubation, the endotracheal tube was positioned properly at the upper incisor teeth, and the incisor-carina neutral length was measured with the fiberoptic bronchoscope at the carina. Results:The correlation between the incisor-MSJ extension length and the incisor-carina neutral length is significant (P < 0.001) in both adults and children. A formula for the regression line in adults (children) can be obtained as the incisor-carina neutral length (cm) = 0.868 (1.009) × the incisor-MSJ extension length (cm) + 4.260 (0.468) with a high coefficient of determination; r2 = 0.88 (0.98). Conclusions:The airway length from the upper incisor to the carina in the neutral position can be predicted by the straight length from the upper incisor to the MSJ in the fully extended position.

Anesthetic management of an adult patient with Rett syndrome and limited mouth opening -A case report-

Rett syndrome is a neurological disease that occurs only in females and it manifests with mental retardation, seizures, movement disorders, autistic behavior and abnormal breathing. A 19-year-old female with Rett syndrome underwent ophthalmologic surgery under general anesthesia at our institution. Airway control was difficult due to her limited mouth opening. We recommend that anesthesiologists should have proper knowledge about this disease and the patients to avoid the complications and problems that can be encountered during the perioperative period.

Alternative technique for changing from nasal to oral endotracheal tube for orthognathic and nasal surgery by using an airway exchange catheter -a case report-

A 28-year-old male patient with right maxillar, zygomatic arch, orbital wall, and nasal bone fractures had an orthognathic and nasal surgery. Naso-endotracheal intubation is the first choice during surgical correction of dentofacial deformities in an orthognathic surgery; however, its presence can interfere with concomitant surgical procedures on the nose. Traditionally, the naso-endotracheal tube will be removed and replaced with an oro-endotracheal tube. We changed the endotracheal tube from nasal to oral by using an airway exchange catheter.

Preconditioning of isoflurane on spinal cord ischemia can increase the number of inducible nitric oxide synthase-expressing motor neurons in rat

Background Spinal cord ischemia with resulting paraplegia remains one of the most common complications after repair of thoracoabdominal aortic aneurysms or dissection. Inducible nitric oxide synthase (iNOS) is known to have both neuroprotective and neurotoxic effects in the central nervous system. We investigated the possible relationship between the effect of pre-ischemic isoflurane exposure on mild spinal cord ischemia and the inducible nitric oxide synthase (iNOS) expression by using iNOS-specific antibody and pyrrolidinedithio carbamate (PDTC), NF-κB inhibitor, in the ventral horn of spinal cord in rats. Methods The animals were divided into five groups (n = 6 in each group): sham group, control group, PDTC-treated group, isoflurane-treated group, and PDTC/ isoflurane-treated group. In the PDTC-treated groups, 2% 100 mg/kg PDTC was administered intraperitoneally at 1 h before operation and at 24 h and 48 h after reperfusion. The rats in the isoflurane-treated groups received 30 min inhalation of 2.8% isoflurane at 24 h before spinal cord ischemia. Immunohistochemistry was performed to detect iNOS expression in the motor neuron of the ventral horn in spinal cord. Results Preconditioning with isoflurane increased the iNOS expression when compared to the control group (P < 0.05), whereas pre-treatment with both PDTC and isoflurane significantly decreased the iNOS expression compared to isoflurane-treated group (P < 0.05). Conclusions Pre-ischemic isoflurane exposure was related with increase of the iNOS expression via a pathway modulated by NF-κB. iNOS may act as an important mediator of delayed preconditioning with isoflurane for the protective effect against spinal cord ischemia.

Remifentanil prevents tourniquet-induced arterial pressure increase in elderly orthopedic patients under sevoflurane/N2O general anesthesia.

Aims: Prolonged tourniquet inflation produces a hyperdynamic cardiovascular response. We investigated the effect of continuous remifentanil infusion on systemic arterial pressure, heart rate, and cardiac output changes during prolonged tourniquet use in elderly patients under sevoflurane/N2O general anesthesia. Methods: Thirty female patients scheduled for knee replacement arthroplasty were infused with either remifentanil at a target organ concentration of 2.0 ng/mL (remifentanil group, n = 15) or saline (control group, n = 15) after induction of anesthesia. Anesthesia was maintained with sevoflurane and N2O. Heart rate (HR), systolic arterial pressure (SAP), diastolic arterial pressure (DAP), cardiac index (CI), total systemic vascular resistance index (TSVRI), BIS, end-tidal sevoflurane concentration (EtSEVO), and end-tidal carbon dioxide concentration (EtCO2) were measured during the study period. Results: There were significant differences in mean HR, SAP, DAP, and EtSEVO over time between the groups (P = 0.047, P < 0.001, P = 0.017, and P < 0.001, respectively). There was a statistically significant time trend effect (P < 0.001) in HR, SAP, DAP, and CI between the groups, with a statistically significant time-group interaction between the two groups (P = 0.02, 0.007, 0.001, 0.01, respectively). Conclusion: The present study demonstrated that infusion with remifentanil prevented an increase in hemodynamic pressure during tourniquet inflation in elderly patients under sevoflurane/N2O general anesthesia.

General anesthesia for a patient with multiple system atrophy.

Multiple system atrophy (MSA) is a rare, adult-onset neurodegenerative disease [1]. Two clinical features characterize MSA: motor features and autonomic dysfunction [2]. During anesthesia, regulation of cardiovascular instability is an important issue. We report a case of successful general anesthesia in a MSA patient. A 66-year-old man (170 cm, 40 kg) presented for a laparoscopic hemicolectomy. Recent intermittent hematochezia suggested rectal cancer. MSA was diagnosed at age 56, and rapid progression left him bedridden. His past medical history included diabetes and hypertension. Preoperatively, no abnormal finding was detected on a laboratory examination, chest X-ray, or electrocardiography. In operating room, routine monitoring devices for electrocardiography, pulse oximetry, and non-invasive blood pressure, and a noninvasive cardiac output monitor showing cardiac output, cardiac index (CI), and stroke volume variation (SVV) were set up. To address possible cardiovascular instability, arterial cannulation was performed before anesthesia. A central venous catheter has already been inserted through the subclavian vein. Initial bispectral index (BIS) was 87, blood pressure (BP) 150/60 mmHg, heart rate (HR) 75 beats/min, central venous pressure (CVP) 3 cmH2O, CI 2.4 L/min/m2, and SVV 10%. General anesthesia was induced with etomidate 0.4 mg/kg intravenously. With good mask ventilation, 40 mg of rocuronium was injected intravenously, and we tried laryngoscopic intubation. Because of poor mouth opening even after full relaxation with the rocuronium, moving the laryngoscope forward was impossible. So, we performed a bronchoscopic intubation. Anesthesia was maintained with sevoflurane 1.5-2 vol% and intravenous remifentanil 0.05 µg/kg/min in an O2-air mixture at a 1 : 1 ratio. The operation lasted about 4 h and anesthesia was maintained appropriately with BIS at 35-50. At 25 min after induction of anesthesia, the BP abruptly fell from 160/85 to 80/50 mmHg. This was managed successfully with rapid fluid administration and a phenylephrine bolus dose of 40 µg intravenously. HR hardly changed, from 82 to 90 beats/min. However, systolic blood pressure dropped again to 80 mmHg during awakening despite the irritating sensation of the endotracheal tube. Phenylephrine 20 µg raised the BP to 100/60 mmHg again with little change in HR, 70-75 beats/min (Fig. 1). Finally, gentle extubation was tried, and no respiratory event occurred. He was transferred to the surgical intensive care unit, and has been cardiovascularly stable since then. He was returned to the ward next day. Fig. 1 Hemodynamic changes during anesthesia. (A) Indicates the changes in blood pressure and heart rate. There is an abrupt decrease in blood pressure to 80/50 mmHg at 25 min after induction, but almost no change in the heart rate. Similarly, a sudden drop ... The annual occurrence of MSA among those over 50 is ~3 per 100,000 with no gender predilection [1,2,3]. Currently, no definite diagnostic criteria or therapies exist, beyond supportive care [2]. There are several considerations regarding anesthesia in MSA. First, the anesthesiologist should be concerned about sudden hypotension due to dysautonomia. Several authors have reported that regional anesthesia is better than general anesthesia in maintaining cardiovascular stability in MSA because of absence of procedures that may aggravate hypotension, such as positive-pressure ventilation, and the avoidance of anesthetics for maintenance [3]. Nevertheless, there is no evidence that regional anesthesia is necessarily the right answer in MSA patients. In contrast, Cohen [1] reported a successful case of general anesthesia after failure of epidural anesthesia, induction with thiopental and succinylcholine, and maintenance with N2O and methoxyflurane. Ketamine was reported as a successful anesthetic in a MSA patient without hypotension in 1983 [4], because ketamine causes central sympathetic stimulation primarily through parasympathetic inhibition. We decided on general anesthesia for several reasons: noncooperation, the possibility of procedural failure due to involuntary movements, and regional anesthesia not being suitable for laparoscopic surgery. The preoperative hemodynamic state of our patient was stable; however, realizing that MSA patients have a damaged sympathetic system, we decided to use etomidate with its minimal cardiovascular effects. We also used remifentanil, which has been reported to effectively suppress cardiovascular reactions and myoclonus after endotracheal intubation with etomidate [5]. Moreover, in MSA patients, bilateral vocal cord paralysis can be a life-threatening complication [1,2]. This adverse event can be aggravated during the induction or post-extubation period due to several stimuli, such as tracheal intubation under insufficient depth of anesthesia or unnecessary suction during extubation. If a preoperative evaluation is impossible, preventative measures should be used. Although no case has been reported of awake bronchoscopic intubation in MSA patients, it is worth considering in patients who are suspected to have difficult airways if the patients are cooperative. We also prepared an emergency cricothyroidotomy kit; the anesthesiologist should always be ready for an emergency tracheostomy situation. In conclusion, anesthesia in MSA remains a great challenge due to the many potential complications. Anesthesiologists should consider the condition of patients with MSA and carefully decide on the appropriate method of anesthesia for the type of operation.

Age and Gender Are Important Considerations in Choosing the Sniffing Position for Laryngoscopic View

Aims: The sniffing position is considered to be the standard position for direct laryngoscopic viewing. This crossover study evaluated age and gender as variables in comparing the benefits of the sniffing position over simple head extension for laryngeal view during direct laryngoscopy. Methods: Laryngoscopy with a curved blade was performed on 200 anesthetized adults (100 males, 100 females) presenting for routine elective surgery. Glottic visualization was assessed by using the percentage of glottic opening (POGO) score in both simple extension and sniffing positions without the aid of the assistant or external laryngeal manipulation. Each gender group was divided into a younger group (< 50 years) and an older group (≥ 50 years). POGO scores were compared between both positions within each group. Results: Mean (SD) POGO scores increased significantly only in younger male patients from 43% (39%) in the head extension position to 76% (30%) in the sniffing position. Conclusion: The sniffing position seems to be advantageous for getting a better laryngeal view during laryngoscopy for tracheal intubation in adult male patients less than 50 years old.

Airway management of an ankylosing spondylitis patient with severe temporomandibular joint ankylosis and impossible mouth opening

In most cases of surgery requiring general anesthesia, airway management and endotracheal intubation are important procedures that must take place. However, when a patient has ankylosing spondylitis (AS) involving the cervical spine in addition to a temporomandibular joint ankylosis (TMJA), head manipulation is difficult to perform. Also, when a patient has limited mouth opening or is unable to open the mouth altogether, airway management and endotracheal intubation are significantly difficult. We experienced the case of an AS patient who was completely unable to open the mouth due to TMJA, admitted for osteotomy and osteoplasty under general anesthesia. A 34-year-old man (44.7 kg, 132.7 cm) with TMJA was admitted to the Oral and Maxillofacial Surgery Department to receive surgery for the mouth opening disorder. The patient was scheduled to receive corrective surgery for the secondary spinal transformation due to AS and had severe kyphosis in the thoracic and lumbar spine due to complete AS (Fig. 1A). In 1997, the patient underwent a cervical spine u-bar insertion and temporomandibular joint surgery at Cedars-Sinai Medical Center, US. (Fig. 1B). A tracheostomy was also performed which left the patient with a surgical scar on his left neck. At the time of the surgery in 1997, the mouth opening was about 25 mm but several years following the procedure, abnormal coronoid process hypertrophy and TMJA (Fig. 1C) developed. For more than 10 years following the disease development, the patient could not tolerate a solid diet but only a liquid diet such as milk or soy milk. When the patient was finally assessed during this admission, his ability to open his mouth was completely impossible (Fig. 1D). Fig. 1 (A) In this picture, the patient is in a preoperative upright position in which there is severe whole spine kyphosis due to complete ankylosing spondylitis. The plane X-ray of the neck (B) and 3D CT of the skull (C) show the inserted u-bar to cervical ... An anesthetic induction was performed by an anesthesiologist with over 200 awake fiberoptic bronchoscopic intubation experiences. Glycopyrrolate 0.2 mg was given as premedication, and 4% lidocaine was injected trans-tracheally to anaesthetise the trachea. To prevent bleeding from the nasal cavity, gauze soaked with 0.1% epinephrine for 15 minutes was packed in the nasal cavity then, a lubricated 5 mm diameter fiberoptic bronchoscope (LF-TP, Olympus Optical Company, Tokyo, Japan) was passed through the right nostril to confirm the airway. After spraying 4 ml of 4% lidocaine on the vocal cord for 15 seconds, the end of the fiberoptic bronchoscope was passed through the vocal cords, and positioned between the vocal cords and carina. Afterwards, an endotracheal tube was placed. After confirming endotracheal intubation, anesthetic induction was conducted using propofol 90 mg and rocuronium 50 mg. Although the tracheostomy was expected to be difficult due to the limited cervical spine movement and the history of tracheostomy, a tracheostomy set and a jet ventilator were prepared to cope with the emergency situation in airway control during the whole procedure. For anesthesia maintenance, 2% propofol and remifentanil were administered using a computer-controlled infusion pump (Orchestra® Base Primea, Fresenius Vial, France). During the surgery, the patient remained in a semi-fowlers position, had an EKG within normal range with the blood pressure of 135-80/90-50 mmHg, heart rate of 50-102 beats per minute, and SpO2 at 100%. The operation took 10 hours and 15 minutes. In order to prevent airway obstruction caused by the swelling of the airway, the patient was not extubated and was transferred to the intensive care unit while sedated using dexmedetomidine. At postoperative day 1, a lack of airway swelling and self-respiration was confirmed then an extubation was carefully conducted before the patient was transferred to the general ward. At postoperative day-12, the patient was confirmed to have no problems in airway management, and was discharged. At the time of discharge, the maximum mouth opening was 30 mm. During the hospital stay, no particular problem in airway management was observed. Currently the patient is able to tolerate small amounts of solid foods, and is on physical rehabilitation. In cases where endotracheal intubation using conventional direct laryngoscope is impossible, procedures such as fiberoptic bronchoscopic intubation, retrograde tracheal intubation or tracheostomy may be performed [1,2]. When endotracheal intubation is expected to be difficult due to AS involving the cervical spine, and flexion, extension and rotation of the cervical region are not possible, intubation using noninvasive video laryngoscope such as Glidescope video laryngoscope (GVL, Verathon Inc., Bothell, USA), Pentax-AWS (Pentax Corporation, Tokyo, Japan) and Airtraq optical laryngoscope (Airtraq, Prodol Meditec, Vizcaya, Spain) or fiberoptic bronchoscope should be considered. However, if the patient is accompanied by TMJA, and is not able to open their mouth, use of a video laryngoscope will be impossible, thus fiberoptic bronchoscopic intubation is restricted to the nasotracheal approach. Cases of performing retrograde tracheal intubation on AS patients were reported [3], but this procedure can be hardly applied to patients who are absolutely unable to open the mouth. Additionally, if bleeding caused by guide wire arises, fiberoptic bronchoscopic intubation would be difficult, as well. The incidence rate of epistaxis is considerably high at 19-54% in nasotracheal intubation [4,5] and when epistaxis develops, a view of the fiberoptic bronchoscope can be compromised even by a small amount of bleeding and consequently, endotracheal intubation may be delayed or a risk of hypoxia may increase. Moreover, in patient cases, such as the present case, that has abnormal positioning and impossible mouth opening, the development of epistaxis under conditions of unawareness may result in difficult ventilation, and an increased risk of pulmonary aspiration and accordingly, success of endotracheal intubation cannot be guaranteed. Also, since the triple airway maneuver is not applicable to TMJA, risk of developing airway obstruction caused by the tongue increases under general anesthesia and accordingly, ventilation can hardly be maintained. When fiberoptic bronchoscopic nasotracheal intubation is conducted under conditions of awareness, the risk of developing hypoxia may be reduced, and pulmonary aspiration due to epistaxis may also be prevented and accordingly, the necessity to perform a tracheostomy may be reduced. In conclusion, in case of TMJA with a high risk of airway control due to impossible mouth opening and limited cervical spine mobility, skillful fiberoptic bronchoscopic nasotracheal intubation under conditions of awareness should be considered a safe procedure.