Systemic Absorption and Block after Epidural Injection of Ropivacaine in Healthy Volunteers

Background: For local anesthetics, the process of removal from the site of administration influences the duration of anesthesia and the risk for systemic toxicity to develop. The systemic absorption of epidural ropivacaine and the time profile of sensory and motor block were studied in healthy volunteers.

Methods: Nine persons simultaneously received 150 mg ropivacaine hydrochloride (7.5 mg/ml) epidurally and 40 mg deuterium-labeled (sup 2 H sub 3)ropivacaine hydrochloride (0.25 mg/ml) intravenously. Peripheral arterial and venous plasma samples were collected, and assessments of sensory and motor block were made.

Results: The arterial plasma concentrations increased faster than the venous concentrations, with 50% higher maximum concentrations after both intravenous and epidural administration. The absorption was biphasic. A correlation was seen between the duration of sensory block and the slower absorption half-life; that is, the longer the half-life, the longer the duration. The extent of spread varied among the volunteers, with the median upper block level not exceeding T12. The motor block (Bromage score 1) was of slower onset (median, 0.4 h) and of shorter duration (median, 4.1 h) than the sensory block (onset, 0.2 h; duration, 6.5 h at L2 medians).     

Edema treatment during cardiac allograft rejection

BACKGROUND: Interstitial edema of rejecting organs can be correlated with the accumulation of hyaluronan in the transplant; since hyaluronan has strong water-binding capacity, treatment with the hyaluronan-degrading enzyme hyaluronidase reduces not only the hyaluronan content but also the water content of the graft. The aim of the present study was to investigate whether a further reduction of the water content would be the result if hyaluronidase was used in conjunction with classic diuretic substances. METHODS: Five days after heterotopic heart transplantation (PVG to Wistar/Kyoto), recipient rats received hyaluronidase as a continuous intravenous infusion over 2 hours together with either a loop-diuretic (furosemide) or an osmotic diuretic (mannitol). RESULTS: Hyaluronidase was found to reduce the hyaluronan contents of the grafts from 586+/-52 microg/g in control animals receiving vehicle infusion to 161+/-48 microg/g (p < 0.001) and the water contents from 81.3+/-0.4 x 10(-2) U to 79.7+/-0.4 x 10(-2) U (p < 0.05). Combined treatment with furosemide or mannitol did not affect the results and neither furosemide nor mannitol had any intrinsic capacity to affect the water or hyaluronan contents of the cardiac grafts. CONCLUSION: This experiment confirms our previous findings of hyaluronidase as an effective edema-reducing drug and indicate that no additive effect is obtained by a combined therapy with diuretics and hyaluronidase.     

Erratum: Patterns of drug use during a 15 year period: data from a Swedish county, 1988–2002

On page 819, the ATC‐code C10 was placed among antihypertensive treatments, but should not have been included there. ‘The prevalence of antihypertensive treatments in table 2, C03, C07, C09 and C10…’ should have been ‘The prevalence of antihypertensive treatments in table 2, C03, C07, C08 and C09…’     

Gender Differences in Pain and Biomechanical Responses After Acid Sensitization of the Human Esophagus

Our aims were to investigate gender differences to multimodal stimulations of the esophagus after experimentally induced sensitization. Thirty healthy age-matched subjects, 13 males and 17 females, were included. Pain evoked by mechanical and thermal stimuli was assessed before and after perfusion of the lower esophagus with 0.1 N hydrochloric acid. Males were more sensitive to the baseline mechanical stimuli (P < 0.01) and tolerated a lower volume of acid (P = 0.04). After acid perfusion, males were more sensitive than females to distensions (cross-sectional area P = 0.001 and volume P = 0.001). Acid perfusion sensitized both males (P = 0.03) and females (P = 0.04) to heat stimulation but not to cold stimulation (males, P = 0.09; females, P = 0.8). The referral areas for pain evoked by mechanical and thermal stimuli were larger in females compared with males both before and after acid perfusion (P = 0.002). In females only the referred pain area increased to heat stimulations (P = 0.02). Acid infusion resulted in a more hyperreactive esophagus (P = 0.03) but the hyperreactivity was not gender-dependent. In conclusion, males were more sensitive to mechanical and chemical esophageal stimuli and showed acid-evoked mechanical hyperalgesia. Females had significantly larger referred pain areas to the stimulations. The differentiated response to peripheral and central pain mechanisms may explain the gender-related differences seen in several gastrointestinal disorders.