ARX-derived auditory evoked potential index and bispectral index during the induction of anesthesia with propofol and remifentanil

A new commercial auditory evoked potential (AEP) monitor (A-line AEP monitor) was developed to calculate an index (ARX AEP index; AAI) by automatically using the amplitudes and latencies of the AEP. We investigated 30 patients before spine surgery. AAI; bispectral index (BIS); relative (%) delta, theta, alpha, and beta; spectral edge frequency; median frequency; mean arterial blood pressure; heart rate; and oxygen saturation were obtained simultaneously during stepwise (1.0 micro g/mL) induction of target-controlled propofol concentration until 5.0 micro g/mL, followed by an infusion of 0.3 micro g. kg(-1). min(-1) of remifentanil. Every minute, the patients were asked to squeeze the observer's hand. Prediction probability (Pk), receiver operating characteristic, and logistic regression were used to calculate the probability to predict the conditions AWAKE, UNCONSCIOUSNESS (first loss of hand squeeze), and steady-state ANESTHESIA (5.0 micro g/mL of propofol and 0.3 micro g. kg(-1). min(-1) of remifentanil). Although a statistically significant difference among the conditions was observed for AAI, BIS, mean arterial blood pressure, median frequency, and %alpha, only AAI and BIS were able to distinguish UNCONSCIOUSNESS versus AWAKE and ANESTHESIA versus AWAKE with better than Pk = 0.90. The modern electroencephalographic variables AAI and BIS were superior to the classic electroencephalographic and hemodynamic variables to distinguish the observed anesthetic conditions. IMPLICATIONS: The modern electroencephalographic ARX-derived auditory evoked potential index and the bispectral index were superior to the classic electroencephalographic and hemodynamic variables for predicting anesthetic conditions. Variables derived from the auditory evoked potential did not provide an advantage over variables derived from spontaneous electroencephalogram.     

Validation of the stages of change with mild,moderate, and strenuous physical activity behavior,intentions, and self-efficacy

The stages of change construct of the Transtheoretical Model (TTM) has been proposed for examining exercise adoption. Studies investigating the construct validity of the stages of change for exercise have used physical activity of moderate or higher intensity as operationalization criterion. Since it has been shown that physical activity of lower intensity also provides health benefits, we investigated whether the stages of change appropriately address lower intensity physical activity. Data with respect to the stages of change as well as behavior, intention and self-efficacy associated with mild, moderate, and strenuous exercise were collected in a sample of 467 males and females aged 20 - 85. Results show that the stages of change can be distinguished by moderate and strenuous but are not consistent with mild exercise. Implications for future research utilizing the stage of change conceptualization are discussed and development of new stage assessment instruments for mild exercise is recommended.     

Hyperhomocysteinemia and vitamin B-12 deficiency in elderly using Title IIIc nutrition services

BACKGROUND: The effect of the folate food fortification program on the prevalence of hyperhomocysteinemia in the older population with coexisting vitamin B-12 deficiency is not known. OBJECTIVE: The objective was to determine the prevalence of hyperhomocysteinemia and vitamin B-12 deficiency in elderly who were using Title IIIc nutrition services, after folate food fortification in the United States. DESIGN: Demographic, nutritional, cognitive, routine diagnostic, and serum methylmalonic acid (MMA) and total homocysteine (tHcy) tests were performed in a convenience sample of 103 elderly enrolled in nutrition service programs in rural northeast Georgia. A subgroup (n = 27) was treated with vitamin B-12, 2.5 mg, and a multivitamin with 400 micro g folic acid, 2 mg vitamin B-6, and 27 mg ferrous fumarate. RESULTS: The total cohort included 103 participants (+/- SD age: 76.4 +/- 8.1; 80% female; 68% white, 32% African American). Vitamin B-12 deficiency (serum vitamin B-12 < 258 pmol/L and MMA > 271 nmol/L) was present in 23%. Mean serum folate was high, 39.3 nmol/L, and no subject had serum folate < 6.8 nmol/L. Mean tHcy was 17.6 +/- 7.2 micro mol/L in vitamin B-12-deficient subjects and 10.8 +/- 3.6 micro mol/L in those who were nondeficient. Determinants of high tHcy were vitamin B-12 deficiency, high serum creatinine, and low red blood cell folate. Those with vitamin B-12 deficiency were more likely to have poor cognition (58% compared with 20%, P < 0.001) and anemia (38% compared with 18%, P = 0.042). High-dose oral B-12 therapy lowered mean MMA and tHcy by 49% and 32%, respectively. CONCLUSION: Vitamin B-12 deficiency was prevalent and was associated with poor cognition, anemia, and hyperhomocysteinemia.     

Even moderate chronic renal failure is associated with impaired acute and long-term outcome after coronary angioplasty

End-stage renal failure requiring maintenance haemodialysis is known to be a strong independent predictor of mortality and complications after coronary interventions. In contrast, data about the outcome of patients with moderate chronic renal failure is very limited and was therefore evaluated in this study in patients with coronary angioplasty (PTCA). This was a retrospective case-control study of 66 patients with moderate chronic renal failure who underwent PTCA, and who were matched to 66 PTCA patients with normal renal function and followed up by telephone interviews. In hospital, patients with renal failure suffered significantly more often from local complications (12.1 vs 0%, P = 0.004) and acute deterioration of renal function after PTCA (7.6 vs 0%, P = 0.023) than their matched controls. Angiographic success after PTCA was not significantly different (85 vs 83%, n.s.) as was the case with in-hospital mortality (6.1 vs 3.0%, n.s.). During follow up (100% complete), 18 patients (27.3%) with renal failure had died compared with seven controls (10.6%; OR 3.2, P = 0.015). Even if deaths from non-cardiac causes in three patients with renal failure were excluded, death after PTCA occurred significantly more often in the renal failure group (P = 0.015, log rang test). Multivariate analyses with stepwise logistic regression identified impaired left ventricular function (OR 2.24, 95%CI 1.33-3.77), elevated serum creatinine (OR 2.02, 95%CI 1.24-3.31) and smaller height (OR 0.91, 95%CI 0.86-0.98) to be independently associated with death. In conclusion, in this matched-pair study, patients with chronic renal failure suffered from more in-hospital complications and from markedly increased long-term mortality after PTCA.