JOURNAL HOME CME HOME THIS MONTH PAST ISSUES ETOC COLLECTIONS AUTHORS REVIEWERS EDITORIAL BOARD FEEDBACK RSS HELP
		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a colleague Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Durant, P. A. C. Articles by Yaksh, T. L. Search for Related Content PubMed PubMed Citation Articles by Durant, P. A. C. Articles by Yaksh, T. L.

Distribution in Cerebrospinal Fluid, Blood, and Lymph of Epidurally Injected Morphine and Inulin in Dogs

Received from the Department of Neurosurgical Research, Mayo Clinic, Rochester, Minnesota.

Abstract

We describe procedures for catheterizing the epidural space, the azygos vein, and the thoracic lymph duct of dogs without using fluoroscopy. The success rates of the procedures were 100, 80, and 50%, respectively (n = 10). To assess the validity of the model, ³H-morphine and unlabeled morphine (2 mg) were injected epidurally in ten dogs. Lumbar cerebrospinal fluid (CSF), azygos venous blood, arterial blood, and lymph were sampled before and 5, 20, 60, 120, 180, 240, 300 and 360 min after injection. During the first 20 min, morphine levels in the azygos vein were about three and ten times greater than arterial and lymphatic levels, respectively (n = 3; P < 0.01). Morphine levels were significantly greater in the azygos vein (n = 8) and the femoral artery (n = 10) during the first 20 and 60 min than they were later, respectively (P < 0.05). In the lymph (n = 5), the levels of morphine at 60 min were statistically greater (P < 0.05) than levels at 4, 5, and 6 hr. At no time were the concurrent arterial and lymph levels different from each other. In the lumbar CSF, the morphine peak concentration was reached 5–60 min after epidural injection and ranged between 5 and 93 µg/ml. In the CSF, the levels of morphine were significantly greater during the first 20 min than later (n = 7; P < 0.05). The washout of the lumbar CSF curve for morphine appeared to be fitted by a two-compartment open model. The t_1/2- and t_1/2-ß values were 14.7 ± 7.2 min and 106 ± 45 min, respectively (mean ± SD). Cumulative percentages of the epidural dose of morphine passed into the azygos system within the first 5, 20, 60, and 120 min after injection were calculated to be 4.0 ± 2.1, 23.5 ± 14.6, 49.2 ± 34.2, and 55.9 ± 35.3, respectively (mean ± SD; n = 8). Both ¹⁴C-inulin and ³H-morphine were injected epidurally in one dog and intrathecally in another dog. In the CSF, morphine appears to be cleared at a rate similar to that of inulin. The fraction of morphine and inulin crossing the dura after epidural injection was calculated to be 0.31% and 0.59%, respectively.

Key Words: ANESTHETIC TECHNIQUES, EPIDURAL—morphine • ANALGESICS—morphine

This article has been cited by other articles:

				T. Nishiyama, R. J. Y. Ho, D. D. Shen, and T. L. Yaksh The Effects of Intrathecal Morphine Encapsulated in L- and D-Dipalmitoylphosphatidyl Choline Liposomes on Acute Nociception in Rats Anesth. Analg., August 1, 2000; 91(2): 423 - 428. [Abstract] [Full Text] [PDF]

				R. Clement, J.-M. Malinovsky, P. L. Corre, G. Dollo, F. Chevanne, and R. L. Verge Cerebrospinal Fluid Bioavailability and Pharmacokinetics of Bupivacaine and Lidocaine after Intrathecal and Epidural Administrations in Rabbits Using Microdialysis J. Pharmacol. Exp. Ther., May 1, 1999; 289(2): 1015 - 1021. [Abstract] [Full Text]

Anesthesia & Analgesia® is published for the International Anesthesia Research Society® by Lippincott Williams & Wilkins with the assistance of Stanford University Libraries' HighWire Press®. Copyright 2006 by the International Anesthesia Research Society. Online ISSN: 1526-7598   Print ISSN: 0003-2999