Sympathetic hyperactivity, hypertension, and tachycardia induced by stimulation of the ponto-medullary junction in humans.

OBJECTIVE: The purpose of this study is to investigate changes in autonomic activities and systemic circulation generated by surgical manipulation or electrical stimulation to the human brain stem. METHODS: We constructed a system that simultaneously recorded microsurgical field videos and heart rate variability (HRV) that represent autonomic activities. In 20 brain stem surgeries recorded, HRV features and sites of surgical manipulation were analyzed in 19 hypertensive epochs, defined as the periods with transient increases in the blood pressure. We analyzed the period during electrical stimulation to the ponto-medullary junction, performed for the purpose of monitoring a cranial nerve function. RESULTS: In the hypertensive epoch, HRV analysis showed that sympathetic activity predominated over the parasympathetic activity. The hypertensive epoch was more associated with surgical manipulation of the area in the caudal pons or the rostral medulla oblongata compared to controls. During the period of electrical stimulation, there were significant increases in blood pressures and heart rates, accompanied by sympathetic overdrive. CONCLUSIONS: Our results provide physiological evidence that there is an important autonomic center located adjacent to the ponto-medullary junction. SIGNIFICANCE: A large study would reveal a candidate target of neuromodulation for disorders with autonomic imbalances such as drug-resistant hypertension.

McGRATH MAC video laryngoscope assistance during transesophageal echocardiography may reduce the risk of complications: a manikin study.

BACKGROUND: Although transesophageal echocardiography (TEE) is considered a relatively safe diagnostic monitoring method, blind probe insertion is associated with pharyngeal trauma. Through visual observation of the esophageal inlet with the McGRATH video laryngoscope, it may be possible to insert the TEE probe at an appropriate angle and prevent pharyngeal trauma. We conducted a manikin study to investigate whether the use of the McGRATH video laryngoscope for TEE probe insertion reduced the pressure on the posterior pharyngeal wall. METHODS: Twenty-seven junior (inexperienced group) and 10 senior (experienced group) anesthesiologists participated in this study. The TEE probe was inserted into an airway manikin in a blind fashion (blind group) or under visualization with the McGRATH (McGRATH group) video laryngoscope (three times each). A sealed bag filled with normal saline was placed on the back of the posterior pharyngeal wall of the manikin and connected to a patient monitoring system via a pressure transducer. We measured the internal bag pressure and approximated this value to the pressure on the posterior pharyngeal wall. RESULTS: The pressure on the posterior pharyngeal wall was significantly lower in the McGRATH group than in the blind group (p < 0.001) and was significantly reduced when the McGRATH was employed in both the inexperienced (p < 0.001) and experienced (p < 0.001) groups. CONCLUSIONS: These findings suggest that TEE probe insertion under the assistance of the McGRATH video laryngoscope can reduce the pressure on the posterior pharyngeal wall, regardless of the clinician's experience, and may inform clinical practice with the potential to reduce probe insertion-associated complication rates.

Failure of a "foolproof" pin-index medical pipeline system.

BACKGROUND: The pin-index medical gas pipeline system, which complies with Japan Industrial Standard (JIS), is considered to be "foolproof" and is widely used in Japan to avoid medical gas misconnections. CASE PRESENTATION: The wall-mounted gas outlet used in our hospital (NSV outlet, CENTRAL UNI, Co., Ltd., Tokyo, Japan) contains multiple sockets, which connect to hoses with gas-specific pins. Each socket is covered with a gas-specific plastic pin guide, which is considered to make the system foolproof; i.e., to prevent misconnections. However, while checking an anesthesia machine in accordance with the guidelines developed by the Japanese Society of Anesthesiologists, an anesthesiologist found that one of the gas-specific plastic pin guides covering the wall-mounted gas outlets had disappeared; and hence, the gas outlet system was no longer foolproof. A subsequent verification test performed by engineers of the system's manufacturer revealed that the plastic pin guides could be dislodged by applying 29.4 N of vertical force. CONCLUSIONS: It is important to check that gas outlet systems are functioning in a gas-specific manner when they are used for clinical purposes.

[Usefullness of Beta-blocker for Hemodynamic Changes Induced by Uterotonic Drug in a Patient with Hypertrophic Obstructive Cardiomyopathy Undergoing Elective Cesarean Section].

Combined spinal-epidural anesthesia (CSEA) was given to a 27-year-old woman with hypertrophic obstructive cardiomyopathy (HOCM) for a selective cesarean section. After the injection of uterotonic drug via uterine muscle and a vein after delivery, the patient developed dyspnea, tachycardia, ST-change on elecrocardiogram and hypotension. It is important in HOCM patients to control heart rate and left ventricular contractile force. We started to infuse beta-blocker (landiolol, 10 µg x kg(-1) x min(-1)) and improved these symptoms of the patient. This case demonstrates that CSEA is safe for HOCM patients and beta-blocker is effective to improve hemodynamic changes induced by uterotonic drug in these patients.

[A Case of Penetrating Injury of the Neck in Which It Was Difficult to Secure the Airway].

A 76-year-old man sustained a penetrating neck injury caused by a metal rake following an accidental fall. On admission, he showed clear consciousness and no dyspnea. CT revealed that the tips of three prongs of the rake were located close to the vertebral artery and trachea. Cerebral angiography identified an injury to the vertebral artery, but no injury to the trachea or oropharynx. He was scheduled for vertebral artery embolization under general anesthesia. Since the neck must be stabilized, we chose to perform rapid sequence induction of general anesthesia with endotracheal intubation using a fiberoptic bronchoscope. Fiber-optic intubation was more difficult than had been expected, and the SpO2 decreased; therefore, mask ventilation was performed using only the jaw-thrust maneuver without neck extension. Although we attempted fiberoptic intubation 5 times, we were unable to obtain a view of the airway for tracheal intubation. We considered tracheostomy, but, finally, 35 min after anesthesia induction, we succeeded in endotracheal intubation using Airwayscope® without neck movement. The glottis was noted to have deviated from the midline. No severe hypoxemia occurred during the clinical course. Various airway management devices have been developed, and we should consider switching quickly to alternative methods.

Successful esophageal bypass surgery in a patient with a large tracheoesophageal fistula following endotracheal stenting and chemoradiotherapy for advanced esophageal cancer: case report.

A 63-year-old man with esophageal achalasia for more than 20 years complained of respiratory distress. He was admitted as an emergency to the referral hospital three months previously. Computed tomography revealed tracheobronchial stenosis due to advanced esophageal cancer with tracheal invasion. He underwent tracheobronchial stenting and chemoradiotherapy. A large tracheoesophageal fistula (TEF) developed after irradiation (18 Gy) and chemotherapy, and he was unable to eat. Thereafter, he was referred to our hospital, where we performed esophageal bypass surgery using a gastric conduit. A percutaneous cardiopulmonary support system was prepared due to the risk of airway obstruction during anesthesia. A small-diameter tracheal tube inserted into the stent achieved ordinary respiratory management. No anesthesia-related problems were encountered. Oral intake commenced on postoperative day 9. He was discharged on postoperative day 23 and was able to take in sustenance orally right up to the last moment of his life. Esophageal bypass under general anesthesia can be performed in patients with large TEF with sufficient preparation for anesthetic management.

[Successful internal jugular vein puncture with ultrasound guidance for a terminal life stage patient in sitting position].

We experienced an internal jugular vein cannulation of a terminal life stage patient suffering from serious peritonitis carcinomatosa with severely edematous limbs. He could not lie down on a bed because of dyspnea due to high abdominal pressure caused by massive ascites. We examined his internal jugular vein with ultrasound device, and found that it kept high venous pressure even in his inspiratory phase, although in sitting position. Internal jugular vein cannulation was successfully performed at first attempt by using ultrasound guide with no complications including air embolism, pneumothorax and bleeding. We considered that positive pressure of jugular vein during a respiratory cycle of the patient was obtained from his unconscious Valsalva's maneuver by increasing intrathoracic pressure following high abdominal pressure. Ultrasound-guided vascular access technique is useful and safe even in terminal life stage patients under palliative care.

[A Kumamoto model of clinical training in tracheal intubation for paramedics].

BACKGROUND: Since July 2004, the Japanese Ministry of Health, Labor and Welfare approved certified paramedics to perform emergency prehospital tracheal intubation. A specialized training system in tracheal intubation has been established in Kumamoto Prefecture. METHODS: The Kumamoto Prefectural Medical Control Organization, a tracheal intubation task force was established: consisting of the departments of Anesthesiology at Kumamoto University and 11 other major hospitals, along with Kumamoto Prefecture and the 14 prefectural fire-departments. This group published the Kumamoto training guidelines and a training system for paramedics. RESULTS: Kumamoto Prefecture appealed for support of paramedic activity on television and in newspapers as public education. The prefectural governor officially asked hospitals to train paramedics. Because 9 of the 14 fire-departments had no regional teaching hospital, trainees were matched with other hospitals by the task force. The task force published a pamphlet to inform surgical patients about tracheal intubation training and to recruit patients as practice volunteers. Anesthesiologists undertook significant roles in making arrangements to facilitate the project at their hospitals, in addition to teaching paramedics prior to surgical procedures. CONCLUSIONS: The Medical Control Organization, Kumamoto Prefecture, anesthesiologists and emergency response personnel worked together successfully to promote the training program for clinical tracheal intubation by paramedics.

Mental strain in medical students during simulator training measured by forehead sweating.

Forehead sweating developed in 78% of medical students when they attempted tracheal intubation on a simulator, and increased during subsequent attempts if the first attempt was not successful. Thus, forehead sweating may be a useful index of mental strain.