AIMTo examine the quantitative relationship between solution specific conductivity and the permeability of tetracaine HCl, and to investigate the effect of receptor solution specific conductivity on the iontophoretic transport.

METHODSAn in vitro study was carried out to determine the iontophoretic permeability of tetracaine hydrochloride through rat skin. Iontophoretic flux of tetracaine hydrochloride through excised rat skin was determined using Valia-Chien two-chamber diffusion cells with a constant d.c. current and Ag/AgCl electrodes. The specific conductivities of donor and receptor solution were also measured.

RESULTSIontophoretic flux of tetracaine hydrochloride increased with a decrease of anion (chloride ion) concentration in receptor. And the iontophoretic permeability (ER, ER is the enhancement ratio, and ER = iontophoretic flux/passive flux) for tetracaine hydrochloride was directly related to the conductivity of receptor solution when other conditions were held constant. Linear regressions confirmed that ER was related to inverse of overall specific conductivity of donor and receptor solution [1/(ks.d + ks.r), ks.d and ks.r are the specific conductivity of donor and receptor solution].

CONCLUSIONThe results suggest that specific conductivity of receptor solution may be a important factor for the iontophoretic permeability of a solute.

Administration, Cutaneous ; Anesthetics, Local ; administration & dosage ; pharmacokinetics ; Animals ; Iontophoresis ; Male ; Rats ; Rats, Sprague-Dawley ; Skin Absorption ; Tetracaine ; administration & dosage ; pharmacokinetics

BACKGROUND: Nalbuphine is one of the opioid agonist-antagonists and is used frequently in the anesthetic field. Usage is focused on potent analgesic action and the adjuvant of narcotics because of less complications with preserved analgesia. The most common routes of administration for postoperative pain control are epidural and intravenous, so we compared both pharmacokinetic profiles. METHODS: Twelve patients were randomly divided into two groups. All patients were given a spinal anesthesia with tetracaine hydrochloride. One group (n = 6) received nalbuphine 10 mg via epidural route and another group (n = 6) received the same dose via intravenous route. Venous blood was drawn at 0, 0.25, 0.5, 1, 2, 4, 6 and 8 hours to measure plasma nalbuphine concentrations. Analysis was performed by high performance liquid chromatography with an electrochemical detector. RESULTS: At 0.25 hour, the plasma concentration of nalbuphine was significantly higher in the epidural administration group (49.48 +/- 4.98 ng/ml) than in the intravenous administration group (40.44 +/- 1.64 ng/ml). At 6 and 8 hours, the plasma concentration of nalbuphine was significantly higher in the epidural administration group (5.98 +/- 1.86 ng/ml, 3.85 +/- 0.94 ng/ml) than in the intravenous administration group (3.80 +/- 0.33 ng/ml, 2.43 +/- 0.32 ng/ml). Clearance, elimination half life, volume of distribution and AUC were not significantly different between the two groups. CONCLUSIONS: The plasma concentrations of nalbuphine via epidural route and intravenous route were similar in both groups after 0.25 hour to 6 hours. At 0.25 hour and after 6 hours, the epidural administration group had a higher plasma concentration of nalbuphine than the intravenous administration group.
Administration, Intravenous* ; Analgesia ; Anesthesia, Spinal ; Area Under Curve ; Chromatography, Liquid ; Half-Life ; Humans ; Nalbuphine* ; Narcotics ; Pain, Postoperative ; Plasma* ; Tetracaine

PURPOSE: Previous lumbar spinal surgery (PLSS) is not currently considered as a contraindication for regional anesthesia. However, there are still problems that make spinal anesthesia more difficult with a possibility of worsening the patient's back pain. Spinal anesthesia using combined spinal-epidural anesthesia (CSEA) in elderly patients with or without PLSS was investigated and the anesthetic characteristics, success rates, and possible complications were evaluated. MATERIALS AND METHODS: Fifty patients without PLSS (Control group) and 45 patients with PLSS (PLSS group) who were scheduled for total knee arthroplasty were studied prospectively. A CSEA was performed with patients in the left lateral position, and 10 mg of 0.5% isobaric tetracaine was injected through a 27 G spinal needle. An epidural catheter was then inserted for patient controlled analgesia. Successful spinal anesthesia was defined as adequate sensory block level more than T12. The number of skin punctures and the onset time were recorded, and maximal sensory block level (MSBL), time to 2-segment regression, success rate and complications were observed. RESULTS: The success rate of CSEA in Control group and PLSS group was 98.0%, and 93.3%, respectively. The median MSBL in PLSS group was higher than Control group [T4 (T2-L1) vs. T6 (T3-T12)] (p < 0.001). There was a significant difference in the number of patients who required ephedrine for the treatment of hypotension in PLSS group (p = 0.028). CONCLUSION: The success rate of CSEA in patients with PLSS was 93.3%, and patients experienced no significant neurological complications. The MSBL can be higher in PLSS group than Control group.
Aged ; Anesthesia, Spinal/*methods ; Female ; Humans ; Lumbar Vertebrae/*surgery ; Male ; Middle Aged ; Prospective Studies ; Tetracaine/*administration & dosage

OBJECTIVETo observe the anesthetic effect of combined superficial anesthesia and auricular point injection for nasal endoscopy surgery.

METHODSForty cases of grade I - II as ASA for nasal endoscopy surgery were randomly divided into a combined auricular point injection and superficial anesthesia group (group A) and a simple superficial anesthesia group (group B), 20 cases in each group. Both groups accepted superficial anesthesia 2 times on the bilateral nasal cavities with cotton pieces that was immersed in the mixed solution of 1% Tetracaine 30 mL and 0.1% Adrenaline 2 mL. In group A, bilateral auricular points of Shenmen and Waibi (externol nose) were injected with 0.1 mL Vitamin B1 solution before the superficial anesthesia. After 10 min of observation, surgery was carried out. During the surgery, the patients only accepted a small amount of vasoactive substance and Fentanyl according to the changes of patient's blood pressure, heart rate and pain feeling.

RESULTSThe total effective rate of 90.0% in the group A was significantly better than 75.0% in the group B (P<0.05). The rate of using analgetic and vasoactive substance in the group A was obviously less than that of the group B.

CONCLUSIONCombined auricular point injection and superficial anesthesia has good anesthetic effect for nasal endoscopy surgery.

Acupuncture Points ; Adult ; Aged ; Anesthesia ; methods ; Anesthetics, Local ; administration & dosage ; Ear ; Endoscopy ; Female ; Humans ; Injections ; Male ; Middle Aged ; Nose ; surgery ; Pain ; drug therapy ; Tetracaine ; administration & dosage

Combining benzodiazepine with opioid has been used for analgesia and sedation during spinal anesthesia, but many authors have warned that combined administration of these drugs produces potent drug interaction that places patients at high risk for hypoxemia and apnea. This study was undertaken to observe the effect of combined use of diazepam with fentanyl on hemodynamic response and change in SaO in twenty healthy adult patients undergone elective surgery with spinal anesthesia. All of the patients were divided into the control and experimental group, and whom spinal anesthesia with 0.5% tetracaine the 12 mg and epinephrine 0.2 mg, were performed. To the control(Group I) and experimental group(Group 2) the combined dose of diazepam 0. 075 mg/kg with fentanyl 1 ug/kg, and diazepam 0.15 mg/kg with fentanyl 2 ug/kg, were given, respectively, by intravenous injection 1 hour after spinal anesthesia started. Blood pressure, heart rate and SaO2 of the two groups were compared at the time before administration of study drugs and 1 min, 2 min, 2 min, 4 min, 5 min, 10 min, 30 min and 60 min after administration of study drugs. The results were as follows. 1) SaO2 was significantly decreased in group 2 than Group 1 after study drugs were administed intravenously. 2) In both group, decrease in SaO2 was significant at the first 5 minutes after intravenous administration of study drugs. 3) SaO2 fell to 90% of the control value after the administration of study drugs in 6 patients of Group 2(60%). 4) Hemodynamic changes after intravenous administration of study drugs were statistically significant but not so clinically in both group. We concluded that combined intravenous administration of benzodiazepine and opioid under spinal anesthesia requires the careful monitoring of hemodynamic response and ventilatory status continuosly with those monitoring devices already in use and pulse oximeter. Availiability of skilled anesthesiologists for airway management and administration of supplemental oxygen are very important in combined intravenous administration of benzodiazepine and opioid.
Administration, Intravenous ; Adult ; Airway Management ; Analgesia ; Anesthesia, Spinal* ; Anoxia ; Apnea ; Benzodiazepines ; Blood Pressure ; Diazepam* ; Drug Interactions ; Epinephrine ; Fentanyl* ; Heart Rate ; Hemodynamics* ; Humans ; Injections, Intravenous ; Oxygen ; Tetracaine

This study was undertaken to clarify the effects of glucocorticosteroids on intraocular pressure and the combined effects of acetazolamide and glucocorticosteroid on ocular pressure. Male and female rabbits, weighing 1.7-2.2kg, were divided into 5 groups: 1) saline-treated group, 2) hydrocortisone (0.5 %)-treated group, 3) prednisolone (0.5 %)-treated group, 4) fludrocortisone (0.1% )-treated group, 5) dexamethasone (0.1% )-treated group. Drugs were instilled 4 times a day for 3 weeks, and ocular pressure was checked in each group on second and third week. Following 3 weeks instillation of glucocorticoids, ocular pressure was checked in each animal at 15, 30, 60, and 120 minutes after intravenous administration of acetazolamide (10mg/kg). Under 0.5% tetracaine anesthesia, facility of outflow and flow rate of the aqueous humor were also measured with a tonometer. The results of the experiments were as follows: 1) The mean ocular pressure rose significantly in all glucocorticoid-treated groups, and the rise was especially marked in the dexamethasone-treated group. 2) The mean facility of outflow of the aqueous humor decreased significantly in the dexamethasonetreated group, but it remained with little change in the other glucocorticoidtreated group. 3) The ocular pressure-lowering action of acetazolamide was suppressed significantly at 30 minutes after the treatment with acetazolamide in the hydrocortisone and prednisolonetreated groups, but it was not suppressed in the fludrocortisone and the dexamethasonetreated groups. 4) The flow rate of the aqueous humor was suppressed significantly (36.2 %) at 30 minutes after the treatment with acetazolamide in the control group, but it was not suppressed significantly in g]ucocorticoid-treated groups.
Acetazolamide* ; Administration, Intravenous ; Adrenal Cortex Hormones* ; Anesthesia ; Animals ; Aqueous Humor ; Dexamethasone ; Female ; Fludrocortisone ; Glucocorticoids ; Humans ; Hydrocortisone ; Intraocular Pressure* ; Male ; Prednisolone ; Rabbits ; Tetracaine