The segmental spread of epidural analgesia was measured in seventeen surgical patients aged between 17 and 52 years, and in fourteen patients between 60 and 77 years. The upper level in the young was 6.29(+/-1.56) thoracic vertebra level, but in the elderly was 4 (+/-0.65_ thoracic vertebra level at 20 minutes after epidural injection of 1.5% lidocaine 20 ml. A given volume of solution spreads to 0.9, 1.07, 1.54, 2.29 segments greater upper extent at 5, 10, 15, 20 minutes after epidural injection and 0.57, 1.07 segments greater lower extent at 5, 10 minutes in the elder than young. So with increasing age relatively small amounts of solution are required, to produce the same extent of anesthesia in the young.
Aged* ; Analgesia, Epidural* ; Anesthesia ; Humans ; Injections, Epidural ; Lidocaine ; Spine

During the last decade, non-rebreathing systems have been used extensively for pediatric anesthesia, but if this is used for long periods, invariable dryness of the airway develops, leading to decreased ciliary functionand reduced transport of secretions, thus producing stagnation which interfs with respiratory function postoperatively. The use of a to-and-from system for infant anesthesia had disadvantages, such as the dead space was excessive at the start of each use increased with the exhaustion of soda lime, the apparatus being clumsy and difficult to handle, and the sodalime crurable, and powder was blown into the patient's face and airway. A new circle system was divided for the Ohio infant circle system, two unidirectional valves removed, a Holm's valve attached to the corrugated tubes. It has been used fo 13 anesthetics in children aged from 3 months to 8 years in the Department of Anesthesiology, Hanyang University, College of Medicine from November to December of 1980. The conclusions are as follows: 1) The degree of the oral temperature was lower in the non-rebreathing system than in the new circle system, but was no significance between the two groups. 2) The systemic temperature of the new circle system was 29.8+0.9 degrees C, and the systemic temperature of the non-rebreathing system was 27.5+0.4 degrees C, so there was a meaningful difference between the two groups. 3) Preansthetic temperature of the soda-lime in the new circle system was 24.5+1.6 degrees C, and 30 min. after the induction was 34.5+3.4 degrees C, so it increased by more than 10 degrees C. This might suggest that it was helped the body temperature and the humidification of the airway. 4) The PCO2 levels 30 min. after induction was meaningfully lower in both systems. This might suggest that it was due to hyperventilation. 5) The gas flow of the non-rebreathing system averaged 6L/min. and the gas flow of the new circle system was 2L/min., so the consumption of fresh gas and anesthetic agent was low in the comparison with the former. Theremer this might suggest that it helped the humidity of the airway, the function of the mucous membrane, and the body temperature. 6) As Holm's valve, its weight 12gm, its resistance 0.5cm-H2O, its deadspace 1ml, was used for both spontaneous and controlled respiration in small children with the circle system. It might suggest that of can compensate for the disadvantages of the old circle systems and non-rebreathing systems.
Infant ; Child ; Male ; Female ; Humans