Pre-emptive Infiltration of Lidocaine Reduces Formalin Pain Behavior in Rat / 대한마취과학회지

Surgical tissue damage induces dual phenomenon of peripheral and central sensitization. Postoperative pain could be partially explained by neuronal hyperexcitability. As a postoperative pain model, formalin test, subcutaneous injection of formalin in the rat hind paw, results in initial vigorous flinching(phase 1), depends on acute chemical stimulation, followed by cessation of activity, and then resumption of flinching(phase 2), which depends on central sensitization. Pre-emptive analgesia, given before the onset of a painful stimuli, reduces or ptevents postoperative pain by preventing this central sensitization. This study was performed to evaluate the effect of local infiltration of lidocaine as a pre-emptive analgesia in the formalin test. Forty experimental rats were divided four groups; CONTROL group(without any treatment), POST group(0.04 mL of 1% lidocaine injection 5 min after formalin injection), PRE group(0.04mL of 1% lidocaine 5 min before formalin injection), and SHAM group(injection of normal saline 5 min before formalin injection). All animals received inhalation anesthesia for 15 min before and 5 min after formalin injection. Under halothane inhalation anesthesia, all were injected subcutaneously 0.04 mL of 5% formalin in the distal plantar area of right hind paw. After recovery of anesthesia, the formalin-induced flinching behavior was observed during only the phase 2 period(10-60 min) after formalin injection. The time to first flinching, the mean number of flinches per min, and the mean number of total flinches during phase 2 expressed as a percent of the values of the CONTROL group were compared between the groups with an t-test or an ANOVA. The first flinching was appeared before recovery of anesthesia in CONTROL and SHAM groups. The time to first flinching after formalin injection was 21.2+/-3.4, 16.6+/-3.1 min respectively in PRE and POST groups. It was significantly longer in PRE group than in POST group(P<0.05), despite of 10 min earlier injeetion of lidocaine in PRE group. The mean number of flinches per min was significantly lower in PRE and POST groups(P<0.05) until 25 min after formalin injection, and after that time the difference between PRE group and POST group was significant(P<0.05). The means of the total number of flinches during phase 2, expressed as a percent of the values of the CONTROL poup, were 100+/-17.2%, 31.8+/-13.1%, 76.9+/-14.5% respectively in SHAM, PRE and POST groups. Those in PRE and POST groups were significantly lower than that of CONTROL group(P<0.001), and the difference between PRE group and POST group was significant(P<0.05). In summary, pre-emptive infiltration of lidocaine on formalin test prolongs the duration of analgesia and reduces the severity of formalin pain in rat. Therefore, the infiltration of lidocaine before formalin test is really provided pre-emptive analgesia.

The Effects of Verapamil and Nifedipine on Isolated Human Uterine Arteries / 대한마취과학회지

Isometric tension was recorded in uterine arterial ring preparation contracted by potassium (60 mM) and norepinephrine(1.8 X 10(-7) M). With pretreatment of various concentrations of nifedipine(2.9 x 10(-9) ~2.9 X10(-7) M) and verapamil(2.2 X 10(-7) -2.2 X 10(-5) M), the relaxation was dose-dependent and inhibitory effects of both agents were more marked on the potassium than norepinephrine-evoked contraction. After immersion of the arterial preparation in calcium-free solution, the potassium-evoked contraction was decreased to 21+/-4.1%(mean+/-SEM) of the response in normal Krebs solution and norepinephrine-evoked contraction to 26+/-3.8%. The responses to both agents were completely restored when the calcium concentration was increased to 4.0 mM. Pretreated nifedipine(2.9 x 10(-7) M) in calcium-free solution depressed the potassium-evoked contraction to 7.3+/-1.6% and norepinephrine-evoked contraction to 12+/-3.7%. In addition of calcium(0-4.0mM), the potassium-evoked contraction increased to 30+/-4.6% and that by norepinephrine to 45+/-5.4%. Pretreated verapamil(2.2 X 10(-5) M) in calcium-free solution depressed the potassium-evoked contraction to 14+/-3.6% and norepinephrine-evoked contraction to 18+/-3.3%. In addition of calcium(0-4.0mM), the potassium-evoked contraction increased to 41+/-4.2% and that by norepinephrine to 57+/-4.7%. It was concluded that nifedipine and verapamil relaxed KC1 contracted ring in the presence of external calcium and relaxed norepinephrine contracted ring in both the presence and absence of external calcium. These findings suggest that calcium antagonists interfere with the release of calcium from intracellular sites as well as with the slow inward current of calcium.

Vecuronium Administration for Endotracheal Intubation / 대한마취과학회지

Vecuronium bromide is a nondepolarizing neuromuscular blocking agent with minimal effect on the autonomic nervous system and little or no histamine release. Some investigators have found that as the dose of vecuronium increased from its ED the onset time is decreased. This study was designed to investigate the influences of a divided dose and single large dose on onset time of vecuronium in 40 ASA physical status l and 2 adult patients. The patients were divided into two groups: Gp. l; Priming dose(0.01 mg/kg) of vecuronium 4 minutes prior to intubating dose(0.14 mg/kg) Gp. 2; Single bolus intubating dose(0.15 mg/kg) of vecuronium followed immediately the induction agent. The results were as follows. l) After the priming dose administration, in the Gp. 2, 13 patients complained of side effcts. 2) The onset time (from the end of injection to l00% depression of the twitch tension) were 172.0+/-23.8 seconds in the Gp. I and 164.0+/-27.5 seconds in the Gp. 2. 3) Clinical duration of blockade (from the end of injection to first return of the second twitch of TOF) was 39,2+/-6.4 minutes in the Gp. l. In conclusion, we recommend the single large dose of vecuronium(0.15 mg/kg) for the endotracheal intubation in whom SCC is contraindicated.

Effects of Inspiratory Pressure Preset on Alveolar Gas Exchange Using Anesthetic Ventilator / 영남의대학술지

The study was undertaken to determine the most adequate tidal volume when used volume preset ventilator during anesthesia. The thirty patients were received controlled mechanical ventilation with constant inspiratory pressure of 10 cmH2O and respiratory frequency of 12/minute. The results were as follows: 1) The PH was 7.39±0.01 and it is within normal limit. 2) The PaCO2 was 34.0±0.6 mmHg and it is a slightly hyperventilatory state. 3) The PaO2 was 228.0±8.2 mmHg. 4) The Buffer base was 20.7±0.3 mEq/L and it is a slightly buffer base deficient state. From the above results. We concluded that if patients were fully relaxed during general anesthesia, it is desirable to maintain the inspiratory pressure of anesthetic mechanical ventilator to 10 cmH2O for adequate alveolar ventilation.

The Masagement of Cancer Related Pain / 대한마취과학회지

Some foreign reports state that 60~80 % of patients hospitalized with cancer suffer with pain. The cancer patients usua1ly have exacerbation of pain corresponding to the progre-ssion of the disease. The management of cancer relate? pain includes the followings : 1) Attacking the pathologr causin? the pain 2) Raising the pain thresheld 3) Modulating the pain pathway 4) Interrupting the pain pathwazy. The most important aspect in management of cancer related pain is stepladder approach to ana17esic tailoring. The development of toleranoe with prolonged uke of analgesics requires increasing dose of analgesics. Not only does the increased dose of analgesics affect analgesia but also increases side effectg increases. Chemical nerve blocks and neurosurgical ablation can be used in management of terminal cancer patients. With the development of multimodal approaches to caring cancer patients one shruld be cautious in Using ablative therapy. ln our pain clinics, 123 cancer related pain patients have been managed with non-narc-odic analgesics, narcotic analgesics, celiac plexus block, and intrathecal phenol block, imp-lant ation of permanent epidural catheter.

A Case of Aspiration Pneumonitis during Induction of Anesthesia for Cesarean Section / 대한마취과학회지

Gradually there are increasing tendencies toward Cesarean sections, either intentionally or inevitably. Since two lives are simultaneously in one case, we must make all efforts to administer anesthesia even more cautiously for Cesarean section patients than for other cases. Occasionally, grave problems occur during induction of anesthesia, especially in general anesthesia. Among them, one of the most serious accidents is aspiration of the stomach contents into the lungs by vomiting or regurgitation. This may induce severe complications, such as chemical pneumonitis due to aspiration of liquid acid contents and/or death due to asphyxia of solid materials. Already several decades ago Mendelson and other authorities described a lung syndrome which was associated with aspiration of vomitus in various degrees of acidity. In an emergency Cesarean section, the authors experienced a case of Mendelson's syndrome which was produced by aspiration of liquid acid stomach contents because of an intubation mistake. Immediately after the operation. the patient began to complain of severe respiratory discomfort and a febrile state which continued for several days post-operatively. However, because of intensive nursing care with oxygenation, intermittent positive pressure breathing, large doses of steroids and antibiotics, the patients condition was restored from the acute febrile stage to the pre-operative level. Within five days the chest X-ray films were normal and on the seventh day the patient and her baby were discharged in good condition. We would like to conclude that many different kinds of drugs and/or methods of anesthesia are not alone sufficient in managing dangerous situations, such as energency Cesarean section but intensive pre-operative care and highly proficient techniques are essential as a prophylactic method in undesirable complications.