The Influence of Midazolam on lntraocular Pressure / 대한마취과학회지

Intraocular tension may be acutely changed by many drugs and by various physiologic events. AN acute rise in intracoular tension may be catastrophic if it occurs when the globenis open and leads to expulsion of contents. Most general anesthetics cause a decrease in intraocular pressure, although a few causes increased intraocular pressure. Midazolam is a 1,4-benzodiazepin derivative synthesized by Walser and Freyer in 1975. Earlier studies with midazolam have demonstrated it efficacy for induction of anesthesia and premedication. It is also desirable to know if all anesthetic agents which produce general anesthesia and which are pharmacologically different affect intraocular pressure in a similar manner. Therefore investigation of the influence of midazolam on intraocular pressure in 25 patients was undertaken at the Department of Anesthesiology, Hanyan University. All patients had no known eye abnormalities. The patients were not premedicated. In all patients the intraocular pressure was measured before induction of anesthesia, after instilling a 0.5% tetracaine into the conjunctival sac. A second reading was taken after induction of midazolam (0.2mg/kg of body weight) and a third after injection of succinylcholine(1mg/kg of body weight) and a fourth after endotracheal intubation. A Schiotz tonometer with a 5.5gm and a 7.5gm weight was used. In addition to the tonometric determination, the blood pressure, pulse rate and respiratory rate were recorded before and after induction of midazolam. An attempt was tried to keep the intraocular pressure changed as many and to minimize the other factors affecting intraocular pressure. To achieve this, supine position and constant gas flow was maintained. Special care was taken to avoid pressure on the patients eye and to maintain a fully patent airway to prevent respiratory disturbances leading to straining and increased venou pressure. Endotracheal intubation was performed with the aid of succinylcholine to avoid cough or laryngospasm. The results of the observation with the above mentioned method were tested by student t-test statistically. Each patient acted as his own control. There was a fall in intraocular pressure in 17 patients among 25 patients(average 1.8mmHg), but no significant change followed by the use of midazoam. The blood pressure variations were between 10 and 40 mmHg, during the course of anesthesia and could not be related to intraocular pressure changes. Intraocular pressure changes had no relation to pulse and respiratory rate variations. This finding indicated that benzodiazepine as a class of drugs have well described muscle relaxant properties that are primarily central(supraspinal)rather than peripheral(myoneural) in action. There was a rise in intraocular pressure in 19 patients among 25 patients, followed by the use of succinylcholine and 23 patients among 25 patients, after endotracheal intubation. According to Feldman and Crawley, diazepam potentiated the myoneural blocking effects of gallamine and antagonizes the effects of succinylcholine. Nevertheless Dretchen demonstrated that the clinical doses of diazepam did not potentiated the muscle relants. Our finding showing no apparent succinylcholine interaction with midazolam are consistent with the finding of Dretche.

Epilural Morphine in Treatment of Caneer Pain / 대한마취과학회지

Epidural injection of 2.0 mg morphine with distilled water or 0.9 % normal saline 10 ml were given to a bladder cancer patient with severe chronic intraetable pain which radiated from low abdomen to gluteal and low leg region. The patient had absolute pain relief which began 2~3 minutes to onset, with 3~5 minutes of peak of action and was effective for 20~25 hours (mean 24 hours) without complications or continuous care as an ambulatory patient. It is suggested that the morphine reached the subarachinoid space through the membrane and produced its effect by direct action on the specific opiate receptors in the substantia gelatinosa of the posterior horn of the spinal cord.

The Clinical Investigation of the Neonatal Gastric Acidity / 대한마취과학회지

It is well known that increasing tendency of emergency surgery of congenital snomalies such as tracheoesophageal fistu1a, esophageal atresia, esophageal hiatal hernia, hypertrophic pyloric stenosis,intestinal obstruction, imperforated anus, omphalocele, and meconium ileus by virtue of improvement of pediatric surgical procedure, anesthetic agent, and anesthetic method. The possibility of a low gastric pH and the resultant pulmonary damage if aspirated must be considered in the initial care of the newborn with poor muscle tone or reflex activity as well as in the anesthetic management of neonates. We became interested in the factors determining neonatal gastric pH in this point of view, and have measured gastric pH in 75 unselected neonates, 55 of whom were born vaginally and 20 by cesarean section. In premature infants, pH was high regardless of mode of delivery. In mature infants, pH was 1) significantly lower after vaginal delivery than after cesarean section; 2) tended to be lower after section preceded by labor than after elective section; and 3) was lowest after precipitate delivery. There was no correlation between neonatal gastric pH and duration of rupture of membranes, birth weight, or Apgar score. It was concluded that the mature human fetus produces gastric acidity in response to stresses associated with labor and vaginal delivery.

The Clinical Investigation of Pediatric Caudal Anesthesia / 대한마취과학회지

Many studies have cited occurrences of severe and long-lasting emotional disturbances of almost every kind after surgical procedures, particularly due to the sedatives or narcotics which were administered to control the post-operative pain. In order to control this post-operative pain, pediatric caudal analgesia was performed in 15 infants and children from the age 2 months to 6 years, who were to undergo lower abdomen, perineum and lower extremity surgery. They were induced with inhalation anesthoeia, using nitrous oxide, oxygen and halothane by mask before and during the block. Following the block, infants and children were turned to supine position and the initial concentration of halothane was reduced. All cases were given 10mg/kg of 1% solution of lidocaine. On examination of the level of the analgesia, 13 out of 15 cases had spread higher level than T10, with effective block for surgical procedures. The identification of the sacral cornu is easy and technical failureis lees in comparison than with the lumbar epidural block for infants and children. Thus we can perform this block successfully for infants and children without any complications or accidents. It is especially helpful in the management of postoperative cases due to the effect in control of the postoperative pain. Thus it gives satisfaction to their parents, nurses and doctors. Despite no follow-up study on postoperative emotional reactions, it was considered that there were minimal occurrences of emotional and behavioral sequelae following the hospital and surgical experiences.

"Precurarization" using d-Tubocurarine , Gallamine and Pancuronium - A Comparative Study / 대한마취과학회지

The depolarizing neuromuscular blocking agent succinylcholine, which was synthesized by Hunt and Taveau in 1906, is still regarded as the drug of choice when speed of onset and good intubating conditions matter most. This agent has several disadvantages, some of which may be unpredictable, serious and immediate, for example, muscle pain, bradycardia, rise in intragastric pressure, increase in intraocular pressure and elevation of serum potassium. These disadvantages may be regarded as the side effects of depolarization and indicate a need for a nondepolarizing neuromuscular blocking agent with rapid onset and good muscle relaxation. Simpson et al. described the neuromuscular blocking properties of the nondepolarizing .neuromuscular blocking agent, Fazadinium (AH 8165) in 1972. This initial work indicated a more rapid onset of action than occurs with succinyleholine and without muscle fasciculation or concomitant rise in plasma potassium concentration. However, Coleman et al., Young, t al., Hartley and Fidler, and Metha et al., concluded that using succinylcholine, a ignificantly greater number of patients had excellent intubating conditions at predetermined times after administration than when using Fazadinium. Several reports have indicated that administration of a small dose of nondepolarizing neuromuscular blocking agents would markedly diminish the fasciculation and muscle pains which so frequently occur, when succinylcholine is given. Many other reports have indicated that administration of a small dose of nondepolarizing neuromuscular blocking agents could attenuate or eliminate the adverse effects of succinylcholine such as increased intra-gastric pressure and intraocular pressure, bradycardia, arrhythmia and hyperkalemia. Several investigators have recommended that when small doses of nondepolarizing neuromuscular blocking aKent are given before succinylcholine administration, larger doses of succinylcholine should be given to achieve satisfactory relaxation. A comparative study using d-tubocurarine, gallamine and pancuronium for precurarization indicates that any of them successfully attenuates fasciculation. They have a little antagonizing effect of vocal cord relaxation after succinylcholine administration, but there was no difficulty during endotracheal intubation.