Role of Vestibulosympathetic Reflex on Orthostatic Hypotension in Rats

BACKGROUND: The orthostatic hypotension in response to the assumption of an upright posture is regulated by activation of sympathetic nerves. Role of the vestibular system and neural pathway on orthostatic hypotension were investigated. METHODS: Changes of arterial blood pressure produced by head-up tilting, rotatory stimulation of the vestibular system, or electrical stimulation to the vestibular nerve, vestibular nuclei, and rostral ventrolateral medulla (RVLM) were measured in Sprague-Dawley rats. Also, field potentials were recorded in the vestibular nuclei and RVLM and c-Fos expression was evaluated in the brain stem in order to investigate the vestibulosympathetic pathways. RESULTS: The three phasic blood pressure responses were elicited by head-up tilting: initial fall, early recovery, and late sustained pressure at near control levels, the magnitude of the pressure fall was parallel with the degree of head-up tilting in normal rats. Return position from head-up tilting recovered control level of blood pressure after a brief rapid elevation. However, bilateral labyrinthectomy resulted in exaggerated initial falling and devoid of early recovery phase during postural change. Sinusoidal rotation about off-vertical axis of the vestibular system elicited more elevation of blood pressure than rotation about earth vertical axis. Electrical stimulation of the vestibular nerve, vestibular nucleus, and RVLM produced elevation of blood pressure, which was the most prominent by stimulation of RVLM. Field potentials composed of P, N1, N2 waves in the vestibular nuclei were recorded by stimulation of the vestibular nerve, while weak potentials in RVLM were recorded by stimulation of the vestibular nuclei. An electrical stimulation of the vestibular nuclei expressed c-Fos immunoreactive cells in RVLM. CONCLUSION: These results suggest that the otolith organ of the vestibular system plays a major role in control of orthostatic hypotension, and the pathway of vestibulosympathetic reflex in control of blood pressure involves the vestibular nuclei, RVLM, intermed-iolateral nuclei of the thoracic spinal cord.

Anesthetic Management for Thymectomy in the Patients with Myasthenia Gravis-Eight cases report / 대한마취과학회지

Myasthenia Gravis is a chronic disorder of neuromuscular transmission characterized by weakness, fatigue of voluntary muscles, especially exacerbations and remissions, a rare disease in Korea. Special considerations are required in the anesthetic management of the myasthenic patients undergoing surgery under general anesthesia and in the postoperative respiratory management by anesthesi olgists. Authors report 8 cases of anesthesia, using N20-02-Enflurane without using nondepolarizing and depolarizing muscle relaxants for thymectomy, experienced during the year 1986~1990.

Clinical Analyis of Anesthesia for Emergency Operations / 대한마취과학회지

We Performed 1,662 anesthesia for emergency surgery at Maryknoll Hospital from January 1985 to December 1989, these surgeries were analyzed clinically and statistically according to age, sex, preoperative status, insurance and noninsurance, frequency of emergency operation, presence of full stomach, department, operation site, anesthetic techniques and agents, time & duration of anesthesia, amount of transfusion. The results were as follows: 1) More than half of the total cases were patients in the third and fourth decade of age. 2) The ratio of male to female numbered 0.83: 1. 3) According to the A.S.A.classification of physical status, patients in emergency class 1 were 38.5%. 4) The ratio of insurance patients (1,113 cases, 67%) versus noninsurance parients (549 cases, 33%) was approximately 2:1. 5) Emergency surgery was 6.1% of total surgical cases. 6) 6.7% patients of emergency surgery had full stomach. 7) The most frequent emergency operations were done by general surgery (43.5%), and obstetrics & gynecology (28.6%). 8) Most common diseases in order, were appendicitis (457 cases), Cesarean section (335 cases), intracranial hematoma (202 cases), repair of tendon, nerve, vessels (71 cases). 9) The most common anesthetic technique for emergency surgery was general anesthesia (94.6%) followed by spinal anesthesia (3.5%). 10) 47.5 percent of emergency operations were performed during the 6 hours from midday to 6 p. m. 11) The duration of anesthesia was up to 2 hours in 1165 cases (70.1%). 12) The cases requiring transfusion during operation were 21.4% (355 cases) of the total cases (1, 662 cases).

Anesthesia for Thymectomy in Patient with Myasthenia Gravis - Two cases report / 대한마취과학회지

Myasthenia Gravis is a neuromuscular disorder manifested by increasing weakness and fatigability of voluntary muscles with exercise, and partial or complete restoration of function following rest or the administration of anticholinesterase drugs. The anesthesiologists may be called upon to assist in the diagnosis of myasthenis, in treating the patient by artificial ventilation during acute exacerbations, to anesthetise the patient for thymectomy or other surgery. Therefore, the anesthesiologists must be familiar with the diagnosis and treatment of myasthnia gravis to carry on the appropriate therapy. Two cases of anesthesia for thymectomy in myasthenia gravis without using muscle relaxants was experienced, and no respiratory problems were encountered postoperatively.

Clinicsl Evaluation of Electroconvulsive Therapy under General Anesthesia / 대한마취과학회지

This is the report of our clinical experience of 1365 cases of aneethesia for eelectroconvu lsive therapy at the Department of Anesthsiology, Maryknoll Hospital, during the period of March, 1989 to February, 1986. To prevent complications, suck as compressed fracture of the spine, and to improve doctor-patient relationship, softening electroconvulsive therapy is the preferred treatment for indicated cases.The results were as follows: 1) Diagnostic distribution of the patients treated by E.C,T. were schizophrenia 74.3%, affective disorder 15.0%, other psychosis 10.7$. 2) Average number of treatments given to a patient were average 6.7 times, for the entire group,7.8times for schizophrenia, 8.2 times for the patients with mania,5.5 times for the Patients with major depression, 5.6 times for the patients with the other psychosises. 3) Medication required was sufficient with half the dosage of uaual surgical procedu res ; ie, atropine sulfate 0.008 mg/kg, thiopental sodium 2.5 mg/kg, and succinylcholine 0.5 mg /kg. 4) Duration of apnea averaged 2 minutes 30 seconds, awakening averaged 10 minutes, and average duration per treatment was 15 min. 5) Few patients complained of discomfort or phobia, and less personnel and less effort were required. Complications and side effecta due to anesthesia were minimal.

The Oculocardiac Reflex during Strabismus Surgery in Children / 대한마취과학회지

The oculocardiac reflex is developed by surgical or nonsurgical procedures to the eyeball, induding traction on extraocular muscles, This reflex is a decrease in heart rate, although other arrhythmias, including A-V junctional rhythm, A-V block, ventricular premature beat, and cardiac arrest, have been reported. This is the report of our experience of oculocardiac reflex during strabismus surgery in children at Department of Anesthesiology, Maryknoll Hospital during the period between February, 1986 and January, 1987. The results are as follows : 1) In group l (0.02 mg/kg, atropine sulfate premedication), oculocardiac reflex was developed 15 cases of 42 cases (35.7%), and in group ll (0.01 mg/kg, glycopyuolate premedication), oculecardiac reflex was developed 17 cases of 49 cases (34.7%). Comparing group l with group ll, there were similar effect to prevention of the oculocardiac reflex (p> 0.05). 2) In each group, developing of the oculocardiac reflex following traction of medial and lateral rectus muscles were 30.0% and 26.3% in group l, and 28.2% and 28.2% in group ll respectively. This was not significant statistically. 3) The oculocardiac reflex following traction of extraocular muscles was disappeared soon after stopping surgioal manipulation. And, intravenous administration of anticholinergic or retrobulbar block were not used for prevention of the reflex.

The Oculocardiac Reflex during Strabismus Surgery in Children / 대한마취과학회지

The oculocardiac reflex is developed by surgical or nonsurgical procedures to the eyeball, induding traction on extraocular muscles, This reflex is a decrease in heart rate, although other arrhythmias, including A-V junctional rhythm, A-V block, ventricular premature beat, and cardiac arrest, have been reported. This is the report of our experience of oculocardiac reflex during strabismus surgery in children at Department of Anesthesiology, Maryknoll Hospital during the period between February, 1986 and January, 1987. The results are as follows : 1) In group l (0.02 mg/kg, atropine sulfate premedication), oculocardiac reflex was developed 15 cases of 42 cases (35.7%), and in group ll (0.01 mg/kg, glycopyuolate premedication), oculecardiac reflex was developed 17 cases of 49 cases (34.7%). Comparing group l with group ll, there were similar effect to prevention of the oculocardiac reflex (p> 0.05). 2) In each group, developing of the oculocardiac reflex following traction of medial and lateral rectus muscles were 30.0% and 26.3% in group l, and 28.2% and 28.2% in group ll respectively. This was not significant statistically. 3) The oculocardiac reflex following traction of extraocular muscles was disappeared soon after stopping surgioal manipulation. And, intravenous administration of anticholinergic or retrobulbar block were not used for prevention of the reflex.