Electroencephalogram spectral edge frequency,lower esophageal contractility,and autonomic responsiveness during general anesthesia

Both the electroencephalogram (EEG) spectral edge frequency (SEF) and lower esophageal contractility (LEC) indices have been reported to be useful indicators of anesthetic depth. We designed a prospective study to evaluate the relationship between changes in these two variables and objective measurements of physiologic responsiveness to surgical stress (i.e., changes in hemódynamic variables and plasma levels of norepinephrine, epinephrine, total catecholamines, and vasopressin). Eighty-nine consenting adult males undergoing radical prostatectomy procedures under a standardized general anesthetic technique were studied according to a randomized, single-blinded protocol. General anesthesia was induced with 30 µg/kg intravenous (IV) alfentanil, 2.5 mg/kg IV thiopental, and 0.1 mg/kg IV vecuronium, and subsequently maintained with 0.5 µg/kg/min alfentanil, nitrous oxide (N₂O) 67% in oxygen, and 0.8 µg/kg/min vecuronium. Following retropubic dissection, 81 patients (92%) manifested acute hypertensive responses, with mean arterial pressure increasing from 90±14 to 122±14 mm Hg (mean ± SD). This acute hypertensive response was treated with one of three different treatment modalities (20 to 60 µg/kg IV alfentanil, 0.5 to 2.0% inspired isoflurane, or 0.05 to 0.15 mg/kg IV trimethaphan) to return the mean arterial pressure to within 10% of the preincisional (baseline) value within 5 to 10 minutes. Although the mean arterial pressure, heart rate, and plasma levels of catecholamines and vasopressin significantly increased following the surgical stimulus, and decreased after adjunctive therapy, the EEG-SEF and LEC index (LECI) values did not significantly change during these study intervals. Furthermore, using a logistic regression analysis, we observed that preincision EEG-SEF and LECI values could not predict whether patients would manifest a hypertensive response. Therefore, the EEG-SEF and LECI were unreliable indicators of anesthetic depth.This study was supported in part by a grant from the Ambulatory Anesthesia Research Foundation, Los Altos, CA. (Dr White is a member of the Board of Directors.)The authors would like to thank Dan Kuni (Baxter Healthcare) for his assistance in obtaining the equipment used to perform the study; Vinod Kothapa, MD, for his valuable assistance with the anesthetic management of the study patients; Alex K. Mills, MD, for his assistance with the EEG interpretation; and Steven A. Bai, PhD, for his assistance with the plasma alfentanil analyses.     

Pregnancy-related changes in tobacco, alcohol and cannabis use reported by antenatal patients at two public hospitals in South Australia

Background: Australian substance use data do not demonstrate pregnancy-related changes or distinguish between pregnant and lactating women.
Aims: To determine such changes by antenatal patients at two South Australian public hospitals accounting for 35% of the state's births.
Methods: In 2005–2006, all first visit antenatal women at the two hospitals were asked by clinic staff to complete an anonymous, self-administered questionnaire prompting details of substance use, current and previous (while not pregnant or lactating).
Results: Questionnaires were returned by 748 women, 34.4% of 2173 eligible in the study period. Women reported use at significantly lower rates than before pregnancy. Tobacco was most used in pregnancy (18.5%), followed by alcohol (11.8%) and cannabis (4.5%), with negligible use of other illicit substances. There was no significant difference in substance use related to trimester. Women with previous pregnancy losses were significantly more likely to use tobacco and alcohol. Younger women were more likely to use tobacco and cannabis, with no age-related differences in alcohol consumption. First pregnancy was the only factor independently associated with the likelihood of ceasing substance use when pregnant, but only in relation to alcohol.
Conclusions: Women were less likely to use all substances when pregnant, and health-care providers should reinforce and support these decisions. The use of cannabis and alcohol while pregnant was below expectations. Reported tobacco use was concordant with existing data and confirms that the risk of smoking in pregnancy remains a message difficult to communicate in the context of chronic nicotine dependence.     

Short vein grafts: a superior option for arterial reconstructions to poor or compromised outflow tracts?

To determine whether vein graft length is a factor that influences infrapopliteal bypass patency, we reviewed 237 consecutive reversed saphenous vein bypasses performed because of critical ischemia during a 5-year period. One hundred seventeen long vein grafts (LVGs) were longer than 40 cm (42 to 92 cm, mean 60.9 +/- 9 cm) and 120 short vein grafts (SVGs) were 40 cm or shorter (6 to 40 cm, mean 24.7 +/- 8 cm). Ninety-three percent of the LVGs originated from or were proximal to the superficial femoral artery (SFA) whereas all of the SVGs originated at or distal to the SFA. The cumulative patency rate for LVGs at 3 years was 45% and for SVGs was 63% (p less than 0.025). In the absence of an intact pedal arch, 3-year patency rates for LVGs (51 cases) and SVGs (78 cases) were 22% and 53%, respectively (p less than 0.01). High intraoperative outflow resistance measurements (greater than 0.7 mm Hg/ml/min) were encountered in 25 cases. Of these, occlusion within 6 months occurred in six of seven cases with LVGs and in only 8 of 18 cases with SVGs (p less than 0.05). Wound complications at vein harvest sites occurred in 17% of LVGs and in only 6% of SVGs (p less than 0.01). Of 16 additional cases in which a proximal patch angioplasty or percutaneous transluminal angioplasty was performed tandem with a short distal vein graft, four occluded (less than 6 months) and 12 remained patent from 3 to 43 months (mean 12.6 months).(ABSTRACT TRUNCATED AT 250 WORDS)     

Retrograde transport of horseradish peroxidase is specifically impaired in bulbospinal serotonin axons during experimental allergic encephalomyelitis

Bulbospinal monoamine-containing axons appear to be severely damaged in rats with the inflammatory and demyelinating disease, experimental allergic encephalomyelitis (EAE). This paper reports that although bulbospinal serotonin axons are damaged in the disease, cell bodies of origin in the medulla oblongata retain normal morphology. However, these serotonin cells are not able to retrogradely transport the enzyme horseradish peroxidase (HRP) from terminals in the lumbar spinal cord. Most non-serotonin-containing cells in the medulla which project to the lumbar spinal cord retain the ability to retrogradely transport HRP from the lumbar cord during the disease. These findings suggest that there is some specificity to spinal cord axonal damage during EAE.     

Antibody competition studies with gold-labelling immunoelectron microscopy

Competitive studies, involving neutralizing monoclonal antibodies (NTmAbs) to outercoat proteins of Akabane virus were performed by immunoelectron microscopy. The experiments were designed to determine whether the NTmAbs were directed against the same or spatially different epitopes. Characteristics of NTmAbs in direct and indirect gold-labelling studies were determined. It was found that the protein A method gave cross-contamination of the immuno-gold complexes whereas direct conjugation of the NTmAbs to gold probes gave clean, specific and intense labelling. Analysis of dilution curves confirmed that saturation of antigenic sites did not occur and secondly determined the optimum working dilutions for the conjugated probes. The data generated in the preliminary studies enabled reliable results to be obtained from the double-labelling competitive experiment. We found that the 2 NTmAbs were directed to either the same epitope or to 2 separate but neighbouring epitopes where the binding of one NTmAb inhibited the binding of the second. The results demonstrate that if reliable data is to be obtained in double-labelling immunoelectron microscopical studies then experiments must be meticulously designed.     

Dentinal candidiasis in cancer patients

Two examples of an unusual presentation of oropharyngeal candidiasis in cancer patients are offered. The light and scanning electron microscopic appearances of candidiasis involving the dentin of teeth are described. The potential significance of recognition of this form of candidiasis in cancer patients is discussed.     

MR and CT assessment for ischemic cardiac disease

Magnetic resonance imaging and/or contrast-enhanced multidetector computed tomography may be used separately or, often more effectively, in an integrated fashion, to address important issues in patients with coronary artery disease causing ischemic cardiac disease (ICD). These issues include complications of myocardial infarction, such as ventricular dysfunction, myocardial wall rupture, aneurysm formation, intracavitary thrombus, mitral insufficiency, and pericarditis, as well as aspects of planning and monitoring therapy for ICD, such as revascularization and ventricular aneurysm repair.