Early benefit of preserved cognitive function is not sustained at one-year after cardiac surgery: a longitudinal follow-up of the randomized controlled trial.
PURPOSE: Recently, we showed that processing of shed blood with a continuous-flow cell saver during cardiopulmonary bypass resulted in a clinically significant reduction in postoperative cognitive decline (POCD) six weeks after coronary artery bypass graft (CABG) surgery. The current study examined if the early benefit of reduced POCD was sustained in the same patient population at one-year follow-up. METHODS: One hundred seventy patients (cell saver group, n = 84; controls, n = 86) underwent neuropsychological testing at baseline and one year after surgery. The raw scores for each test were converted to Z-scores, and a combined Z-score of ten main variables was then calculated for each study group. RESULTS: Postoperative cognitive decline was present in 16 of 84 (19%) patients in the cell saver group (95% confidence interval [CI], 10.8 to 27.2) vs 15 of 86 (17.4%) patients in the control group (95% CI, 9.6 to 25.2) (P = 0.786). Six of the 15 patients in the control group with POCD at six weeks had the impairment at one year and five did not; four were lost to follow-up. Three of the six cell saver patients with POCD at six weeks still had impairment at one year, two did not, and one was not tested. Thirteen (15.4%) and nine (10.5%) patients in the cell saver and control groups, respectively, developed new POCD which was not evident at the six-week follow-up. CONCLUSIONS: The short-term preservation of cognitive function in elderly patients using the cell saver management strategy did not translate into a long-term benefit one year after CABG surgery. The presence of progressing cerebrovascular disease may be responsible for the long-term cognitive decline. (ClinicalTrials.gov number, NCT00193999).
PMID: 22290354 [PubMed - as supplied by publisher]
Evaluation of TAPSE as a measure of right ventricular output.
Can J Anaesth. 2012 Feb 3;
Authors: Tousignant C, Kim H, Papa F, David Mazer C
Abstract
PURPOSE: This study was designed to show the relationship between tricuspid annular plane systolic excursion (TAPSE) and stroke volume (SV) by thermodilution using three different methods and also to assess whether TAPSE can track hemodynamic changes associated with volume loading and ephedrine administration. METHODS: This was an observational study in 61 elective patients with a pulmonary artery catheter who were undergoing coronary artery bypass graft surgery in a cardiac surgical centre. We measured TAPSE by three methods using transesophageal echocardiography: M mode, speckle tracking at the lateral wall, and tissue tracking at the inferior wall. There were two interventions: leg raising (volume recruitment) or administration of ephedrine 5 mg iv. Echo and hemodynamic measurements were performed before and after each intervention. RESULTS: Eleven patients were excluded due to poor imaging. There were 26 patients in the leg raising group and 24 patients in the ephedrine group. The correlation coefficient between stroke volume (SV) and TAPSE by M mode, speckle tracking, and tissue tracking was 0.48, 0.44, and 0.09, respectively. There was a significant increase in SV following each intervention; however, the changes in TAPSE by any method and velocity were not large enough to reach statistical significance. CONCLUSION: Tricuspid annular plane systolic excursion by M mode and by speckle tracking correlates modestly with SV. There was no correlation between TAPSE and SV by tissue tracking at the inferior wall of the right ventricle. Tricuspid annular plane systolic excursion by M mode and by speckle tracking does not track changes in SV following either volume loading or ephedrine administration.
PMID: 22302303 [PubMed - as supplied by publisher]
A Prospective Randomized Equivalence Trial of the GlideScope Cobalt® Video Laryngoscope to Traditional Direct Laryngoscopy in Neonates and Infants.
Anesthesiology. 2012 Jan 20;
Authors: Fiadjoe JE, Gurnaney H, Dalesio N, Sussman E, Zhao H, Zhang X, Stricker PA
Abstract
BACKGROUND:: Intubation in children is increasingly performed using video laryngoscopes. Many pediatric studies examine novice laryngoscopists or describe single patient experiences. This prospective randomized nonblinded equivalence trial compares intubation time for the GlideScope Cobalt® video laryngoscope (GCV, Verathon Medical, Bothell, WA) with direct laryngoscopy with a Miller blade (DL, Heine, Dover, NH) in anatomically normal neonates and infants. The primary hypothesis was that intubation times with GCV would be noninferior to DL. METHODS:: Sixty subjects presenting for elective surgery were randomly assigned to intubation using GCV or DL. Intubation time, time to best view, percentage of glottic opening score, and intubation success were documented. We defined an intubation time difference of less than 10 s as clinically insignificant. RESULTS:: There was no difference in intubation time between the groups (GCV median = 22.6 s; DL median = 21.4 s; P = 0.24). The 95% one-sided CI for mean difference between the groups was less than 8.3 s. GCV yielded faster time to best view (median = 8.1 s; DL 9.9 s; P = 0.03). Endotracheal tube passage time was longer for GCV (median = 14.3 s; DL 8.5 s; P = 0.007). The percentage of glottic opening score was improved with GCV (median 100; DL 80; P < 0.0001). CONCLUSIONS:: Similar intubation times and success rates were achieved in anatomically normal neonates and infants with the GCV as with DL. The GCV yielded faster time to best view and better views but longer tube passage times than DL.
PMID: 22270505 [PubMed - as supplied by publisher]
Prevalence of Survivor Bias in Observational Studies on Fresh Frozen Plasma: Erythrocyte Ratios in Trauma Requiring Massive Transfusion.
Anesthesiology. 2012 Jan 20;
Authors: Ho AM, Dion PW, Yeung JH, Holcomb JB, Critchley LA, Ng CS, Karmakar MK, Cheung CW, Rainer TH
Abstract
Observational studies on transfusion in trauma comparing high versus low plasma:erythrocyte ratio were prone to survivor bias because plasma administration typically started later than erythrocytes. Therefore, early deaths were categorized in the low plasma:erythrocyte group, whereas early survivors had a higher chance of receiving a higher ratio. When early deaths were excluded, however, a bias against higher ratio can be created. Survivor bias could be reduced by performing before-and-after studies or treating the plasma:erythrocyte ratio as a time-dependent covariate.We reviewed 26 studies on blood ratios in trauma. Fifteen of the studies were survivor bias-unlikely or biased against higher ratio; among them, 10 showed an association between higher ratio and improved survival, and five did not. Eleven studies that were judged survivor bias-prone favoring higher ratio suggested that a higher ratio was superior.Without randomized controlled trials controlling for survivor bias, the current available evidence supporting higher plasma:erythrocyte resuscitation is inconclusive.
PMID: 22270506 [PubMed - as supplied by publisher]
A Mixed (Long- and Medium-chain) Triglyceride Lipid Emulsion Extracts Local Anesthetic from Human Serum In Vitro More Effectively than a Long-chain Emulsion.
Anesthesiology. 2012 Feb;116(2):334-339
Authors: Ruan W, French D, Wong A, Drasner K, Wu AH
Abstract
BACKGROUND:: Lipid emulsion infusion reverses cardiac toxicity of local anesthetics. The predominant effect is likely creation of a “lipid sink.” This in vitro study determined the extent to which Intralipid® (Fresenius Kabi, Uppsala, Sweden) and Lipofundin® (B. Braun Melsungen AG, Melsungen, Germany) sequester anesthetics from serum, and whether it varies with pH. METHODS:: Bupivacaine, ropivacaine, and mepivacaine were added to human drug-free serum (pH 7.4) at 10 μg/ml. The lipid emulsions were added, and the mixture shaken and incubated at 37°C. Lipid was removed by ultracentrifugation and drug remaining in the serum measured. Additional experiments were performed using 100 μg/ml bupivacaine and at pH 6.9. RESULTS:: Lipofundin® extracted all three anesthetics to a greater extent than Intralipid® (34.7% vs..22.3% for bupivacaine, 25.8% vs..16.5% for ropivacaine, and 7.3% vs..4.7% for mepivacaine). By increasing either concentration of bupivacaine or lipid, there was an increase in drug extraction from serum. Adjusting the pH to 6.9 had no statistically significant effect on the percentage of bupivacaine sequestered. CONCLUSIONS:: Bupivacaine, ropivacaine, and mepivacaine were sequestered to an extent consistent with their octanol:water partition constants (logP). In contrast with previous studies of extraction of lipids from buffer solutions, an emulsion containing 50% each of medium- and long-chain triglycerides extracted local anesthetics to a greater extent from human serum than one containing exclusively long-chain triglycerides, calling into question recent advanced cardiac life support guidelines for resuscitation from anesthetic toxicity that specify use of a long-chain triglyceride. The current data also do not support recent recommendations to delay administration until pH is normalized.
PMID: 22273855 [PubMed - as supplied by publisher]
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