Color flow duplex screening of infrainguinal grafts combining low- and high-velocity criteria.

The aim of this prospective study was to evaluate the ability of duplex ultrasonography to identify infrainguinal grafts at high risk for failure. The criteria used identified low flow by low peak systolic velocity (less than 45 cm/s) and stenosis by high velocity (greater than 300 cm/s) or by velocity at the stenosis three times the velocity in the adjacent normal graft. A total of 114 patent grafts were scanned and compared with concurrent angiograms. Duplex scanning correctly identified 18 high-risk grafts by low-flow criteria and an additional 21 by stenosis criteria. There was one false-negative finding (sensitivity 98 percent). The velocity ratio of the stenosis to the adjacent graft was useful in estimating the degree of stenosis. Color flow duplex imaging reduced examination time through visual feedback by highlighting the graft and areas of high velocity. These results indicate that color flow duplex scanning, combining low- and high-peak systolic criteria, is a very sensitive screening test in the early detection of failing grafts.

Image compression by texture modeling in the wavelet domain.

High-quality image compression algorithms are capable of achieving transmission or storage rates of 0.3 to 0.5 b/pixel with low degradation in image quality. In order to obtain even lower bit rates, we relax the usual RMS error definition of image quality and allow certain "less critical" portions of the image to be transmitted as texture models. These regions are then reconstructed at the receiver with statistical fidelity in the mid- to high-range spatial frequencies and absolute fidelity in the lowpass frequency range. This hybrid spectral texture modeling technique takes place in the discrete wavelet transform domain. In this way, we obtain natural spectral texture models and avoid the boundary blending problems usually associated with polygonal modeling. This paper describes the complete hybrid compression system with emphasis on the texture modeling issues.

Accept me for myself: African American women's issues after breast cancer.

PURPOSE/OBJECTIVES: To identify the personal issues and concerns of African American women who are breast cancer survivors. DESIGN: Exploratory. SETTING: Southeastern United States; urban community. SAMPLE: A total of 24 women were recruited from churches and the community; 16 women participated in focus groups. METHODS: Two focus group sessions were held in a community library. Audiotaped interviews were transcribed and analyzed for themes that described issues the women had to deal with after treatment for breast cancer. MAIN RESEARCH VARIABLE: Women's perceptions of the impact breast cancer had placed on their personal lives, including sexuality. FINDINGS: Five themes emerged-body appearance, social support, health activism, menopause, and learning to live with a chronic illness. CONCLUSIONS: African American women have concerns that are similar to, but different from, those of Caucasian women. Further research is needed to identify culturally appropriate care. IMPLICATIONS FOR NURSING PRACTICE: Assess the effects of treatment on women's personal lives. Know where women can purchase prostheses that match their skin tones. Refer minority women to support groups specifically designed for them.

Lexical, syntactic, and stress-pattern cues for speech segmentation.

Many sources of segmentation information are available in speech. Previous research has shown that one or another segmentation cue is used by listeners under certain circumstances. However, it has also been shown that none of the cues are absolutely reliable. Therefore, it is likely that people use a combination of segmentation cues when listening to normal speech. This study addresses the issue of how young adults use multiple segmentation cues (lexical, syntactic, and stress-pattern) in combination to break up continuous speech. Evidence that people use more than one cue at a time was found. Furthermore, the results suggest that people can use segmentation cues flexibly such that remaining cues are relied upon more heavily when other information is missing.

Ultrasound demonstration of prenatal renal vein thrombosis.

Renal calcification following renal vein thrombosis (RVT) has a virtually diagnostic lace-like radiological pattern. It has been seen as early as the first day of life, [1-3], indicating prenatal disease. This case report illustrates the sonographic appearance of such calcifications which to our knowledge has not been described. We observed abnormalities on a prenatal ultrasound at 37 weeks of gestation and calcifications within the kidney on ultrasound during the neonatal period in an infant of a mother with Class B diabetes mellitus.

Stressful pre-operative preparation procedures. The routine removal of dentures during pre-operative preparation contributes to pre-operative distress.

One hundred and twenty-four patients (76 women and 48 men) were interviewed within the first 36 hours after operation. Fifty per cent of those studied were denture wearers. They were asked to fill in a questionnaire which registered their levels of distress about the various pre-operative preparation procedures. The most common factors contributing to pre-operative distress were waiting for transfer to the operating theatre, the prohibition of fluids and the removal of dentures.

A double-blind comparison between nitrazepam, lorazepam, lormetazepam and placebo as preoperative night sedatives.

Benzodiazepines are used as hypnotics to reduce anxiety and give a good night's sleep on the night prior to surgery. In a double-blind procedure, patients were given either lorazepam (2 mg or 4 mg), lormetazepam (1 mg or 2 mg), nitrazepam 10 mg or placebo. Measures were taken of sleep, anxiety, memory and after-effects. There was no evidence that the drugs reduced anxiety, nor evidence of amnesia. Quality and length of sleep was shown to be better for nitrazepam (P less than 0.05), lorazepam 2 mg (P less than 0.05) and lorazepam 4 mg (P less than 0.01), compared with placebo. However, significantly higher ratings of clumsiness and confusion as after-effects were found with nitrazepam (P less than 0.05), and clumsiness (P less than 0.005), slurred speech and blurred vision (P less than 0.01), sleepiness, nausea, weakness and confusion (P less than 0.05) with lorazepam 4 mg. It was concluded that lorazepam 2 mg produced the greatest net benefit.

Comparison of diazepam with midazolam as i.v. sedation for outpatient gastroscopy.

We studied 26 patients in a double-blind investigation to compare psychomotor and cognitive recovery for 30 h after sedation for day-case gastroscopy with i.v. diazepam 0.15 mg kg-1 or midazolam 0.07 mg kg-1. Significantly more patients reported side effects at 7, 10 and 30 h post-gastroscopy after diazepam than after midazolam (P less than 0.05). Compared with baseline, the midazolam group was significantly impaired in critical flicker fusion threshold, reaction time, dexterity and visualization tasks up to 4 h after administration (P less than 0.05). There was a significant association between midazolam and amnesia for the procedure (P less than 0.001).

The impact of the appearance of the anaesthetist on the patient's perception of the pre-operative visit.

The clinician's appearance is often considered a symbol which identifies and defines specific characteristics of the individual. Opinion of both lay and medical personnel on appropriate clothing inclines towards formal dress. Our aim was to assess the effect of the anaesthetist's appearance during a ward visit on the patient's evaluation of either the visit or the anesthetist himself. In our sample of 66 patients we found no evidence that the style of dress (formal: suit and tie, informal: jeans and open-necked shirt) affected that evaluation. However, when 138 patients were asked to rate the desirability of items of clothing for a male hospital doctor they expressed a preference for traditional clothing; a suit was rated as desirable and jeans as one of the four most undesirable items. We conclude that despite the conservatism of expressed opinions, the clothing worn by the anaesthetist is irrelevant to the patient's satisfaction with the visit.

A survey of concurrent drug therapy among day unit patients.

In order to assess the reliability of drug information supplied by day-stay cases, 85 consecutive patients were interviewed. A comparison of the interview answers with the details previously volunteered during the admission procedure showed an increase of 80% in the information given by the patient. While the detailed interviewing technique is time-consuming and may not be infallible, this substantial increase in information highlights problems in the current routine.

Propofol in short gynaecological procedures. Comparison of recovery over 2 days after anaesthesia with propofol or thiopentone as sole anaesthetic agent.

Recovery was assessed over 48 hours after anaesthesia with propofol or thiopentone as sole anaesthetic agent in 36 unpremedicated gynaecological patients. Immediate recovery, as measured by the Steward scale, was shown to be quicker for the patients given propofol. At one hour postoperatively the thiopentone group showed impaired visual-motor coordination on the aiming test (p less than 0.01) and dexterity task (p less than 0.05), and a slowing of reaction time (p less than 0.01). Patients given propofol showed only an increase in reaction time (p less than 0.05). By 2 hours the thiopentone group showed impairment only in the aiming task (p less than 0.05). No further significant impairment was detected at 4, 24 or 48 hours. However, patients reported symptoms throughout the 48 hours indicative of residual drug effects. There was a substantial practice effect with some tests which may have obscured impairment. It can be argued therefore that the better recovery profile after propofol is still evident at 24 hours.

Effects of small concentrations of isoflurane on some psychometric measurements.

We have investigated the effects of 9.5% and 14.1% MAC concentrations of isoflurane on some psychometric measurements. Both concentrations depressed peak saccadic velocity (P < 0.01), choice reaction time (P < 0.05) and visual analogue scores for sedation (P < 0.05), but not the critical flicker fusion threshold. The incidence of errors in saccade tasks increased in a dose-related fashion, which made analysis of peak saccadic velocity less accurate at more than 10% MAC. The percentage error itself was an indicator of the depth of sedation. All the objective measures correlated highly with the estimated brain tension of isoflurane (r2 = 0.86-0.96), but not the visual analogue score for sedation (r2 = 0.51). This suggests that a combination of peak saccadic velocity, percentage error and choice reaction time is a potentially useful batch of tests to measure recovery from anaesthesia.

Interaction of H2-receptor antagonists and benzodiazepine sedation. A double-blind placebo-controlled investigation of the effects of cimetidine and ranitidine on recovery after intravenous midazolam.

H2-receptor antagonists differentially inhibit cytochrome P450 and this may affect the rate at which benzodiazepines are metabolised. However, it is not known whether this delayed clearance results in prolonged psychomotor impairment. In a randomised double-blind trial 28 healthy volunteers received two single doses of midazolam (0.07 mg.kg-1) at an interval of one week during which they took cimetidine 400 mg, ranitidine 150 mg or placebo, each twice daily. Recovery from the benzodiazepine was monitored on each occasion over a 12 h period using a battery of psychometric tests. There was wide individual variation in performance; however, an overall measure of impairment indicated a significant difference at 2.5 h (p < 0.05), the cimetidine group having a high impairment score. This decrement appeared to be in cognitive and psychomotor functions and was not reflected in the subjective assessment.

Reducing smoking. The effect of suggestion during general anaesthesia on postoperative smoking habits.

In a double-blind randomised trial, 122 female smokers undergoing elective surgery were allocated to receive one of two prerecorded messages while fully anaesthetised. The active message was designed to encourage them to give up smoking whilst the control message was the same voice counting numbers. No patient could recall hearing the tape. Patients were asked about their postoperative smoking behaviour one month later. Significantly more of those who had received the active tape had stopped or reduced their smoking (p < 0.01). This would suggest a level of preconscious processing of information.

Propofol-induced anaesthesia. Double-blind comparison of recovery after anaesthesia induced by propofol or thiopentone.

Postoperative psychomotor and cognitive recovery were assessed after anaesthesia induced by either propofol or thiopentone, and maintained with nitrous oxide and halothane in 40 unpremedicated dental patients. Performance was shown to be impaired one hour postoperatively for the whole sample in hand-eye coordination (p less than 0.001), reaction time (p less than 0.001) and digit span (p less than 0.05). There was evidence of impairment at 3 hours postoperatively in reaction time (p less than 0.05) and ataxia (p less than 0.01). Performance also deteriorated in the dexterity and aiming tasks. Patients reported significantly less clumsiness by 24 hours in blurred vision and shivering (p less than 0.05) and by 48 hours less coughing (p less than 0.05). However, there was no significant difference between groups. No evidence showed that recovery in the propofol group was faster, so it was concluded that induction with propofol offered no advantage when anaesthesia is maintained with nitrous oxide and halothane for the periods of time reported in this study.

Effects of posture, phonation and observer on Mallampati classification.

We have studied the effects of phonation and posture on the Mallampati classification of view of the pharyngeal structures. Differences between observers were allowed for by the experimental design and log-linear modelling. Sixty-four patients were assessed on the ward, sitting upright, with and without phonation, by each of two observers. Another 64 patients were assessed without phonation, but both upright and supine, again by both observers. Phonation (the patient saying "Ah") produced a marked, systematic improvement of view; moving to the supine posture produced a small, systematic, non-significant worsening of the view. Differences between observers were non-systematic but substantial. About 25% of patients phonated spontaneously. It is recommended that anaesthetists make their own assessments of Mallampati classification, with the patient in either of the postures but always either with or without phonation, and thereby gradually "calibrate" their assessments against the degree of difficulty encountered in intubation.

The subjective effects of low-dose propofol. A double-blind study to evaluate dimensions of sedation and consciousness with low-dose propofol.

In this study the subjective effects (sedation and mood) of subanaesthetic doses of propofol were examined in 28 healthy male volunteers. A computer model was used to predict the infusion profiles necessary to obtain steady state propofol plasma concentrations of 0.3 microgram.ml-1, 0.6 microgram.ml-1, 0.9 microgram.ml-1. Objective measures of sedation from saccadic eye movement and choice reaction time gave significant dose responses at each level but a battery of psychometric tests failed to show dose-related subjective responses. Of particular note in the subjective data is the lack of a difference between groups or even of a consistent trend within the data. This suggests that a low concentration of propofol in plasma does not induce euphoria or a sense of well-being. The anecdotal evidence available for mood changes with propofol therefore remains unsubstantiated.

Reversal of benzodiazepine sedation with the antagonist flumazenil.

The effectiveness of the benzodiazepine antagonist, flumazenil, was evaluated in a randomized double-blind clinical study in which diazepam 0.2 mg kg-1 or midazolam 0.1 mg kg-1 was used for i.v. sedation. We studied 120 day-case patients undergoing gastroscopy and treated with either flumazenil 0.1-2 mg or placebo after the procedure. Psychometric assessment of four aspects of recovery over a 3-h period showed that flumazenil attenuated the sedative effects of the benzodiazepines, but did not antagonize the sedation completely. For patients sedated with diazepam, there was a significant effect of flumazenil on speed of motor co-ordination after 90 min (P less than 0.01), and for those given midazolam a similar effect was found at 20 min (P less than 0.01). However, after 3 h all four groups of patients had not returned to baseline performance in accuracy of motor co-ordination (P less than 0.01) and cortical arousal (P less than 0.05), and the two groups sedated with diazepam still displayed memory deficits (P less than 0.05). Flumazenil did not attenuate the subjective experience of sedation as measured by visual analogue scales. These results indicate that sedation is multidimensional, differentially affecting the hierarchy of cognitive functions. In day-cases, antagonism of benzodiazepine sedation with flumazenil would not hasten the safe discharge of patients.