A randomized, triple-masked, active-controlled investigation of the relative effects of dose, concentration, and infusion rate for continuous popliteal-sciatic nerve blocks in volunteers.

BACKGROUND: It remains unknown whether local anaesthetic dose is the only factor influencing continuous popliteal-sciatic nerve block effects, or whether concentration, volume, or both exert an influence as well. METHODS: Bilateral sciatic catheters were inserted in volunteers (n=24). Catheters were randomly assigned to ropivacaine of either 0.1% (8 ml h(-1)) or 0.4% (2 ml h(-1)) for 6 h. The primary endpoint was the tolerance to transcutaneous electrical stimulation within the tibial nerve distribution at hour 6. Secondary endpoints included current tolerance at other time points and plantar flexion maximum voluntary isometric contraction (22 h total). RESULTS: At hour 6, tolerance to cutaneous stimulation for limbs receiving 0.1% ropivacaine was [mean (standard deviation)] 27.0 (20.2) vs26.9 (20.4) mA for limbs receiving 0.4% [estimated mean difference 0.2 mA; 90% confidence interval (CI) -8.2 to 8.5; P=0.02 and 0.03 for lower and upper boundaries, respectively]. Because the 90% CI fell within the prespecified tolerance ±10 mA, we conclude that the effect of the two concentration/volume combinations were equivalent. Similar negative findings were found for the secondary outcomes. CONCLUSIONS: For continuous popliteal-sciatic nerve blocks, we found no evidence that local anaesthetic concentration and volume influence block characteristics, suggesting that local anaesthetic dose (mass) is the primary determinant of perineural infusion effects in this anatomic location. These findings suggest that for ambulatory perineural local anaesthetic infusion-for which there is usually a finite local anaesthetic reservoir-decreasing the basal rate while increasing the local anaesthetic concentration may allow for increased infusion duration without compromising postoperative analgesia. CLINICAL TRIAL REGISTRATION: NCT01898689.

Spiritual well-being of the individual with amyotrophic lateral sclerosis.

BACKGROUND: A study was conducted to: (1) establish the feasibility and reliability of the Spiritual Well-Being Scale (SWBS) and its religious (RWB) and existential well-being (EWB) subscales in a sample of individuals with ALS; (2) describe the spiritual and religious practices, and spiritual well-being in these individuals; and (3) examine the relationship between spiritual well-being and quality of life. METHOD: A random sample of 60 individuals completed the SWBS at the beginning and end of an ALS clinic visit. Subjects were classified into early, middle or late stage of ALS, using vital capacity and total ALS Functional Rating Scale scores. A subsample completed the Sickness Impact Profile (SIP). RESULTS: The SWBS and its RWB and EWB subscales were found to have high internal consistency and test-retest reliability. There were no statistically significant differences in SWB, RWB or EWB scores among the three stages of ALS. RWB scores were significantly higher than EWB scores overall and within the middle and late stages. Strong negative correlations were found between physical and psychosocial dimension SIP subscores and RWB scores, suggesting that religious well-being may impact quality of life, or vice versa.

Effects of a metalloendopeptidase-24.15. Inhibitor on renal hemodynamics and function in rats.

N-[1-(R,S)-carboxyl-3-phenylpropyl]-Ala-Ala-Phe-p-aminobenzoate (cFP-AAF-pAB), an active-site-directed inhibitor of metalloendopeptidase-24.15, has been shown to lower blood pressure, increase cardiac output and renal blood flow, and potentiate the intravenous bradykinin-induced vasodepressor response. Because in vivo cFP-AAF-pAB can be converted to N-[1-(R,S)-carboxyl-3-phenylpropyl]-Ala-Ala (a compound with angiotensin converting enzyme inhibitory activity) by metalloendopeptidase-24.11, it is possible that some of its effects are due to angiotensin converting enzyme inhibition. In the present study, we questioned (1) whether cFP-AAF-pAB inhibits angiotensin converting enzyme in vivo and (2) whether cFP-AAF-pAB has renal effects that are independent of its conversion to an angiotensin converting enzyme inhibitor. cFP-AAF-pAB alone (3 mumol in 300 microL per rat) almost abolished the blood pressure response to angiotensin I, suggesting that in vivo it inhibits angiotensin converting enzyme. In rats pretreated with a high dose of enalaprilat (1 mg/kg), cFP-AAF-pAB had no further effect on blood pressure, renal blood flow, or potentiation of the vasodepressor response to bradykinin but still increased glomerular filtration rate by 44 +/- 9% (P < .01); urine volume increased by 118 +/- 10% (P < .001), urinary sodium excretion by 230 +/- 31% (P < .001), urinary potassium excretion by 68 +/- 14% (P < .01), and urinary cyclic GMP by 55 +/- 18% (P < .01). All of these changes were significant compared with enalaprilat/vehicle-treated rats. Fractional excretion of sodium and potassium did not differ from controls.(ABSTRACT TRUNCATED AT 250 WORDS)