Effects of single dose, postinduction dexamethasone on recovery after cardiac surgery

BACKGROUND: Corticosteroids have been recommended to facilitate rapid recovery after cardiac surgery. We previously reported that dexamethasone given after induction of anesthesia decreases the incidence of postoperative shivering. We performed a post hoc analysis of the data obtained during that study, focusing on secondary outcomes. METHODS: A total of 235 adult patients undergoing elective coronary or valvular heart surgery were randomized to receive dexamethasone 0.6 mg/kg or placebo after induction of anesthesia. Patients who had pharmacologically treated diabetes mellitus, had hypersensitivity to dexamethasone, or were receiving treatment with corticosteroids were excluded. RESULTS: We found that, compared with placebo, patients receiving dexamethasone were more likely to remain tracheally intubated for 6 hours or less (26.4% vs 10.0%, p = 0.020) and had a lower incidence of early postoperative fever (20.2% vs 36.8%, p = 0.009) and new-onset atrial fibrillation during the first 3 days postoperatively (18.9% vs 32.3%, p = 0.027). However, we could not demonstrate a statistical difference in the intensive care unit or hospital length of stay, or in overall morbidity and mortality. The dexamethasone-treated patients were also more likely to have a higher blood glucose on admission to the intensive care unit (186 mg/dL vs 143 mg/dL, p = 0.012). CONCLUSIONS: Dexamethasone facilitates early tracheal extubation and is associated with a lower incidence of early postoperative fever and new-onset atrial fibrillation. Apart from a treatable decreased glucose tolerance, dexamethasone treatment was not shown to affect morbidity or mortality significantly.     

Posterior corneal curvature changes after myopic laser in situ keratomileusis

OBJECTIVE: To assess the posterior corneal power and asphericity changes after myopic laser in situ keratomileusis (LASIK) and to correlate these changes with the amount of correction and the residual stromal bed thickness. DESIGN: Prospective nonrandomized (self-controlled) comparative study. PARTICIPANTS: Fifty-seven eyes of 14 women and 15 men, mean age at the time of surgery 33 +/- 9 (range, 19-53) years with a spherical equivalent (SEQ) of -1.00 to -15.50 (mean, -5.07 +/- 2.81) diopters (DI). INTERVENTION: All procedures were performed with the Keratom II Coherent-Schwind excimer laser and and the Moria Model One microkeratome (150-microm head). Subjective refractometry, Orbscan slit scanning corneal topography analysis and pachymetry were performed before and 3 months after LASIK for myopia (n=35, -1.00 to -15.50 D, mean -4.75 +/- -3.07 D) or myopic astigmatism (n=22, sphere 0.00 to -9.75 D, mean -4.75 +/- 2.36 D; cylinder -0.75 to -3.50 D, mean -1.68 +/- 0.86 D). Intended ablation depth ranged from 12 to 108 (mean, 48 +/- 22) microm. Topographic raw data were decomposed into a set of Zernike polynomials as published in detail previously, and parameters potentially indicative for detection of a "mild keratectasia" were derived. MAIN OUTCOME MEASURES: Posterior central corneal power and asphericity before and after LASIK were compared, and changes of these variables were correlated with the SEQ change (deltaSEQ)and the residual corneal bed thickness RBT). RESULTS: The mean RBT after LASIK was 280 +/- 42 microm. Overall, change of posterior power (-6.28 +/- 0.22 D/ -6.39 +/- 0.23 D, P=0.02) was statistically significant and change of asphericity (0.98 +/-0.07/1.14 +/- -.20, P<0.0001) was highly significant. In eyes with RBT < or =250 microm, the average change of posterior central power (-0.20 +/- 0.10 D vs. -0.08 +/- 0.18 D) was significantly greater than in eyes with RBT >250 microm (P=0.003). The change of posterior corneal power correlated significantly with deltaSEQ (P=0.004) and the RBT (P=0.002). CONCLUSIONS: Increased negative keratometric diopters and oblate asphericity of the posterior corneal curvature suggest that mild "keratectesia" of the cornea may be common early after LASIK. Further stuudies with longer follow-up are required to clarify whether this biomechanical deformation is progressive and whether a residual bed thickness of >250 microm can completely prevent it.