Intraoperative Methadone Use Is Associated With Reduced Postoperative Pain and More Rapid Opioid Weaning After Coronary Artery Bypass Grafting.

OBJECTIVE: To explore the association between intraoperative methadone use, postoperative pain, and opioid consumption after coronary artery bypass grafting (CABG) surgery. DESIGN: Retrospective cohort study. SETTING: Single academic medical center. PARTICIPANTS: Patients undergoing isolated CABG over a 5-year period. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Demographic data, comorbidities, and intraoperative anesthetic medications were recorded. Primary study outcomes were average and maximum pain scores and morphine milligram equivalent consumption on the first 2 postoperative days (PODs). Linear mixed-effects regression models were used to examine the effect of intraoperative methadone use on study outcomes. Among 1,338 patients, 78.6% received intraoperative methadone (0.2 mg/kg). Patients who did not receive methadone had higher average (estimated [Est], 0.48; 95% confidence interval [CI], 0.22-0.73; p < 0.001) and maximum postoperative (Est, 0.49; 95% CI, 0.23-0.75; p < 0.001) pain scores over PODs 0 to 2. For postoperative opioid consumption, there was a significant intraoperative methadone use-time interaction effect on postoperative opioid use (odds ratio [OR], 2.21; 95% CI, 1.74-2.80; p < 0.001). Across PODs 0 to 2, patients who received intraoperative methadone had a faster decline in postoperative opioid use than those who did not receive intraoperative methadone. Patients who did not receive intraoperative methadone were extubated slightly faster (OR, 0.82; 95% CI, 0.72-0.93; p < 0.01). CONCLUSIONS: Our data suggest that the use of intraoperative methadone is safe, reduces postoperative pain, and expedites weaning from postoperative opioids after CABG surgery.

Preoperative Alcohol Use, Postoperative Pain, and Opioid Use After Coronary Artery Bypass Surgery.

OBJECTIVES: Chronic alcohol use is associated with chronic pain and increased opioid consumption. The association between chronic alcohol use and acute postoperative pain has been studied minimally. The authors' objective was to explore the association among preoperative alcohol use, postoperative pain, and opioid consumption after coronary artery bypass grafting (CABG). DESIGN: A retrospective cohort study. SETTING: At a single academic medical center. PARTICIPANTS: Patients having isolated CABG. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Demographics, comorbidities, and baseline alcohol consumption were recorded. Primary outcomes were mean pain score and morphine milligram equivalent (MME) consumption on postoperative day 0. Among 1,338 patients, there were 764 (57.1%) who had no weekly preoperative alcohol use, 294 (22.0%) who drank ≤1 drink per week, 170 (12.7%) who drank 2-to-7 drinks per week, and 110 (8.2%) who drank 8 or more drinks per week. There was no significant difference in mean pain score on postoperative day 0 in patients who consumed different amounts of alcohol (no alcohol = 5.3 ± 2.2, ≤1 drink = 5.2 ± 2.1, 2 to 7 drinks = 5.3 ± 2.3, 8 or more drinks = 5.4 ± 1.9, p = 0.66). There was also no significant difference in median MME use on postoperative day 0 in patients who consumed different amounts of alcohol (no alcohol = 22.5 mg, ≤1 drink = 21.1 mg, 2-to-7 drinks = 24.8 mg, 8 or more drinks = 24.5 mg, p = 0.14). CONCLUSIONS: There is no apparent association among mild-to-moderate preoperative alcohol consumption and early postoperative pain and opioid use in patients who underwent CABG.

Separation of peptides and proteins by capillary electrophoresis using acidic buffers containing tetraalkylammonium cations and cyclodextrins.

A method for improving separations of peptides and other positively charged species in capillary zone electrophoresis with untreated capillaries using acidic buffers containing tetraalkylammonium cations is described. Tetramethylammonium and tetrabutylammonium cations dynamically modify the capillary surface, leading to a reversal in the direction of the electroosmotic flow. As a result, the adsorption of positively charged peptides and proteins is minimized, and resolution and peak capacity are improved as the migration of cationic analytes is counterbalanced by the electroosmotic flow. The combining effect of reversing electroosmotic flow and cyclodextrin inclusion complexation on separations of closely related peptides and a protein mixture, as well as tryptic digest of hemoglobin is demonstrated.

Monitoring liposome-mediated delivery and fate of an antisense drug in cell extracts and in single cells by capillary electrophoresis with laser-induced fluorescence.

Capillary electrophoresis with laser-induced fluorescence (CE-LIF) detection was used for evaluation of the effectiveness of delivery and fate of a model 25-mer DNA-based phosphorothiate antisense drug in cells. The antisense molecule was delivered to the cells through a simple incubation and by using a cationic liposome (Cytofectin GS 3815). The cationic lipid interacted with the negatively charged antisense to form a more positively charged complex. It was observed that uptake of the liposome-antisense complex by the cell was dependent on concentration of lipid, duration of transfection, and the cell type. The antisense drug interacted with intracellular components such as proteins and additional steps were needed to quantify the free antisense. Proteinase-K was able to release antisense from proteins. However, the addition of sodium dodecyl sulfate (SDS) to the sample or running buffer was more effective than Proteinase-K to release both naked and liposome-bound antisense from the cellular materials. Analysis of single HeLa cells for uptake of the unbound and liposome-complexed antisense revealed averages of 8.9x10(-19) moles and 4.9x10(-18) moles, respectively. The amount of uptake, however, varied greatly among individual cells and depended on the delivery method. With liposome-mediated delivery, the relative standard deviation (RSD) for the amount of antisense in individual cells was 130%, while the variation was much smaller (RSD = 45%) when the cells were incubated with the unbound antisense. These uptake variations agreed with those obtained from flow cytometry analysis.