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In today's ICUs clinicians routinely integrate huge numbers of discrete data points to arrive at a coherent picture of their patients' status. Often the clinician must obtain those data elements from many devices, which makes the problem more difficult. Because presenting data visually amplifies cognition by capitalizing on well-known human perceptual capabilities, it is not surprising that a growing body of research is directed at the effective presentation of visual information in clinical displays. However, developing clinical displays that effectively support clinicians' integration and understanding of many discrete data elements in complex, high technology work domains such as ICUs remains elusive. It may be that traditional analysis and design methods simply are inadequate for this kind of complex environment. Vicente has described a new methodology, called "cognitive work analysis" (CWA), which is targeted at the analysis of complex work domains. The analysis differs from traditional analytic methods in significant ways, particularly in its primary focus on analysis of the work domain, but also in its prescription for explicitly collecting information at five levels (the work domain, diagnostic and treatment tasks, diagnostic strategies, socio-organizational, and clinician skills) that place constraints on the ultimate display design. In this model, the order of data collection is also crucial. Because the work domain constraints tend to be the most permanent, they are likely to have the most impact on design, and so analysis starts there. As the analysis proceeds through the subsequent levels, additional design constraints are identified. We recently used CWA to analyze the information needs for interactive graphical displays that will integrate and represent data in structures that help clinicians visualize a patient's physiological status. We found that the analysis was an effective way to identify information needs at multiple levels. Based on our experience, CWA is a generic methodology that is highly applicable to medical informatics.

There is a growing consensus that human factors issues for anesthesiologists, surgeons, and other operating room personnel require serious attention. We have established a program of collaboration between the University of California Davis Medical Center Departments of Anesthesiology and Surgery and the California State University Sacramento Biomedical Engineering Program to address ergonomic problems in anesthesiology and surgery using a Virtual Instrumentation Laboratory. A 17-workstation Virtual Instrument Laboratory using LabVIEW software on Power Macintosh platforms permits rapid prototyping of medical monitor displays as well as rapid development of data acquisition and processing circuits for physiologic data collection. The Virtual Instrument Lab has been used for three Master's thesis projects and a BME course titled Human Factors in the Design of Medical and Assistive Technology. Course projects have included: 1) The design of novel physiologic data displays for potential use in anesthesia workstations, and 2) The measurement of surface electromyographic signals and heart rate variability to investigate the physical and mental workload of performing laparoscopic surgery. The Virtual Instrument Lab allows BME students to investigate relatively complex human factors issues in anesthesiology and surgery in a short time span.

Objective: The goal of this study was to determine whether the intraoperative vigilance of anesthesia residents is different when they keep a manual record than when an assistant performs the charting., Methods: A total of 9 anesthesia residents were studied during 36 general anesthesia cases on ASA class 1 or 2 patients. In half of the cases, the resident performed all record keeping. In the other half, the anesthesia record was kept by a human assistant. Vigilance was measured as detection rate and response time for the resident to detect a simulated abnormal value displayed on the physiologic monitor. For analysis, anesthesia cases were divided into stages of induction, maintenance, and emergence., Results: Response times and detection rates were not different when record keeping was performed by an assistant, rather than by the clinician. Shorter cases were associated with longer median response times (i.e., lower vigilance) during the maintenance phase, but only when record keeping was done manually., Conclusions: The results demonstrate that anesthesia residents are equally attentive to an experimental signal displayed on an electronic monitor while manually charting as they are when an assistant keeps the record. This brings into question the contention that eliminating the record-keeping task will result in a reduced level of vigilance.

Background: Anesthesia residents take longer to detect changes in electronically monitored data during the induction phase of anesthesia during the maintenance phase. This study was performed to investigate the reasons for this delay and to validate a method of measuring vigilance., Methods: The activity of ten residents was studied during 73 surgical procedures. Data were collected during three 15-min periods from each case: induction, starting with application of the electrocardiograph; maintenance, an arbitrary period between induction and emergence; and emergence, ending with detachment of the electrocardiograph. Vigilance was measured as the time taken to detect a change, from normal to abnormal, of an artificial parameter displayed on the physiologic monitor (response time). An observer simultaneously recorded each time that the resident looked toward the monitors., Results: Vigilance to the monitor display was less during induction and emergence than during maintenance (P < 0.005). Residents spent less total time watching monitors during induction than during maintenance (P < 0.005), and the duration of each monitor observation was shorter (P < 0.0005). Anesthesia residents usually looked at the monitors several times before detecting the abnormal value. The measure of anesthesia vigilance correlated with independent measures of monitor watching time and frequency., Conclusions: The results suggest that during induction of anesthesia, which is a period of high anesthesiologist workload, residents glance toward monitors to gather data rather than scan displays. The results help to validate the method for measuring anesthesia vigilance.

In some individuals, noise appears to have an adverse effect on memory recall. This decrement may result from a shift in the memory strategy being employed. Studies have shown memory strategies used by persons with an internal locus of control differ from those used by persons with an external locus of control. The present investigation asked subjects who were classified as either internal or external in locus of control to recall words presented under conditions of noise and of quiet. Word recall was aided by providing subjects with potential memory strategies. Each word list included words from meaningful content categories (which favor a semantic strategy) and word pairs that rhymed (which favor a perceptual strategy). Though internal and external subjects did not differ in total words recalled, they did differ in their use of strategies. Whereas internal subjects' strategies were unaffected by noise, external subjects decreased their use of the higher level semantic memory strategy (content categories) and increased their use of lower level perpetual (rhymes) strategy in the noise condition. The results are discussed in terms of a differential arousal hypothesis.

One of the causes of a depressed naso-jugal groove is the fixation of the septum orbitale at the level of the inferior-medial portion of the arcus marginalis. To permit the leveling of the groove, it is necessary to liberate the subjacent orbital septum from its fixation to the arcus marginalis. To avoid recurrence of the depression, some fat tissue is properly placed in the undermined space subjacent to the groove. This can be done by free fat grafting or fat pad sliding.

Vigilance is an important but difficult to measure attribute in anesthesia practitioners. We present a modified standard method to assess intraoperative vigilance toward electronic data displays. The response time to detect a simulated abnormal value on the physiologic monitor was measured. Eight anesthesia residents were studied during 60 surgical procedures. Responses to 439 abnormal values were analyzed. The average response time was 61 +/- 61 s (mean +/- SD), and 56% of the detections were made within 60 s. However, 16% of the abnormal values were undetected during the 5 min that they were displayed. Response times and the rate of missed events were greater during induction of anesthesia (a time of high workload) than during the maintenance or emergence phases of anesthesia. Response times were shorter during procedures on ASA 1 patients than on ASA 3 patients. The results suggest that anesthesiologists usually quickly detect abnormal values on physiologic monitors and that less attention is devoted to monitors during periods of high workload.

It has been previously demonstrated that the output of calibrated vaporizers is influenced by the concentration of nitrous oxide in the carrier gas. This study was performed to determine whether helium in the carrier gas affects the output of modern calibrated vaporizers. A factorial design was used to determine the influence of carrier-gas helium concentration, carrier-gas flow rate and vaporizer dial setting on the output of four vaporizers: Ohio Calibrated Enflurane, Ohio Calibrated Isoflurane, Ohmeda Isotec 4, and Dräger Vapor 19.1 Isoflurane. Three vaporizers of each model were tested. Output was converted to % of baseline so that different dial settings could be compared. For a given dial setting, baseline was defined as the output at a carrier-gas flow rate of 3 L.min-1 and helium concentration of zero. The data were analyzed using multiple linear regression. There was an effect of helium concentration on vaporizer output in all models. None of these changes was clinically important, since vaporizer output did not vary by more than +/- 10%, except at high flows and at high helium concentrations with the Ohmeda Isotec 4. It is concluded that these vaporizers can be used safely with helium.

This prospective study was performed to determine whether anesthesia clinicians (i.e., both anesthesiologists and nurse anesthetists) can identify operating room alarms by their distinctive sounds and to identify factors related to alarm recognition accuracy. Nineteen alarms from 15 commonly used devices were recorded. These sounds were played, in a quiet room, to 44 anesthesia clinicians. The clinicians were asked to choose from a list the device that produced the alarm. After this recognition test, the clinicians rated the importance of each alarm and the frequency with which they heard it in the clinical situation. Clinicians correctly identified the alarm source 34% of the time. The recognition rate was higher for alarms rated as heard more frequently; however, alarms that were rated as more important were less likely to be correctly identified. Complexity of the sound did not influence accuracy of recognition. Most errors were attributed to similarities in sound or function, or both, among alarms. We conclude that anesthetists cannot reliably identify current operating room alarms by their distinctive sounds.

When treating nasolabial folds, it is necessary to radically undermine the adjacent tissues before using fat grafts or fat injections in order to place the fat in the proper locations and, thus, prevent placing it inside muscle tissue. The method described here avoids augmenting the volume of the adjacent lip and cheek tissues lateral to the nasolabial fold which can cause poor results.

As plasma potassium concentrations, whether normal or elevated, can be reduced by intravenous administration of either epinephrine or ritodrine, the effects of these drugs were examined during acute hyperkalemia. Six anesthetized dogs were studied every 2 wk, on 18 separate occasions. Hyperkalemia was induced by intravenous infusion of potassium chloride, resulting in plasma potassium concentrations of 9.6 +/- 0.3 mEq/L (mean +/- SEM), bradycardia, and idioventricular rhythm. Dogs were then given slow intravenous injections every 30 min of either saline (controls), epinephrine, or ritodrine. Epinephrine doses were 0.01, 0.1, 1.0, 10, or 100 micrograms/kg; ritodrine doses were 0.1, 1.0, 10, 100, or 1000 micrograms/kg. At the highest does, both epinephrine and ritodrine caused clinically important decreases in plasma potassium, reducing concentrations to below 7.0 mEq/L. Ritodrine had a significantly greater effect than epinephrine. Side effects included hypertension and dysrhythmias with epinephrine, serious hypotension with ritodrine, and tachycardia with both drugs. For both drugs, the doses that caused a decrease in plasma potassium also caused an increase in heart rate and there was a correlation between plasma potassium levels and heart rate. Epinephrine and ritodrine may be useful in treating acute hyperkalemia, but cardiovascular side effects may occur. Increased heart rate could be used as an indicator of therapeutic effect and the magnitude of the increase in heart rate may be helpful in predicting the level of response.

"Scleral show" is an anatomical condition in which the sclera area is visibly exaggerated due to constitutional, evolutive, or endocrine etiology. It can also occur because of iatrogenies, and is considered one of the most complex blepharoplasty complications. Its evolution and poor response to treatment are questionable. The defect is not always linked to an ectropion, and the basic differences between the two are explained. During blepharoplasties, in order to avoid iatrogenic "scleral show," among other complications, one should take special precautions with the quantity and the exact location of the tarsal portion of orbicularis oculi muscle to be resected.

Psychiatric claims under workers' compensation law have increased substantially in recent years. This chapter explores the history and varying jurisdictional standards of workers' compensation law followed by a discussion of issues pertinent to performing a psychiatric evaluation of a claimant for workers' compensation.

In some cases of double chin, the submental fold can become quite obvious. It can persist or even be deepended following a submental fatpad resection if the incision is made following the fold. The steps involved in eliminating this fold are: (1). A curved incision is made 1 cm in front of the fold. (2). The excess fat is reduced, leaving a 1 cm layer attached to the skin. (3). The fold is filled by sliding forward a fat flap taken from the fat remaining on the skin. (4). The sutures in the fat and the skin are not superimposed, to avoid recurrance of the fold.

Teenage runaways were compared to teenage nonrunaways concerning their views on parenting behaviors. In ratings of reasons for running away, the runaways emphasized typical teenage issues such as differences in values from parents and rebellion. On the other hand, nonrunaways gave highest ratings to more dramatic issues such as parental abuse and drug use. Runaways were less likely to want to have children than nonrunaways and, if they did have children, runaways anticipated being very different with their children than their parents had been with them (e.g., more involved and open). Nonrunaways generally expected to be about the same as their parents had been. Suggestions for treatment, based on the findings, are offered.

A prototype anesthesia workstation has been developed to demonstrate the feasibility of a computer-assisted anesthesia workplace. The workstation provides a central display of information and aids the user in controlling and monitoring the anesthesia delivery system. The anesthesiologist interacts with the workstation through a Macintosh computer, which is easy for the clinician to understand and to use. Seventeen sensors and monitors transmit information from the anesthesia delivery system to the computer. The computer monitors this information using a set of rules, evaluated once each breath, to detect changes in the delivery system. If an event is detected, the computer alerts the anesthesiologist with a diagram, a text message, and an audible warning. A laboratory test of the monitoring system was performed to see if it properly identified 26 different critical events during simulated low flow and closed circuit anesthesia. Five hundred and eight-three of 660 simulated critical events (88%) were identified with the unique and correct message. On 35 occasions, multiple messages were displayed, including the correct one. Critical events were misidentified or not detected 42 times. Eight false positive alarms occurred during the 20 h of testing; all occurred as a result of baseline drift in a single transducer. These results demonstrate that a sophisticated monitoring system can reliably diagnose specific anesthesia machine failures.

The traditional approach to the thigh lift calls for placement of the anterior incisions in the inguinal folds. Since the lateral limits of the mons pubis are located in these folds, we have observed that stress after suturing will stretch the pilose portion laterally and downward, resulting in its widening and permitting it to become displaced onto the upper thigh. This is obviously concomitant with the well-known fall of the scar. The mons pubis becomes enlarged. I avoid this condition by placing the anterior incisions high on the inguinoabdominal region and crossing the lateral pilose portions of the mons, reducing its width. The use of this procedure over the past five years has shown that neither the scars nor the pilose area becomes visible on the upper thighs below underclothes or bathing wear; the mons pubis appears young and more congruent with the rejuvenated thighs; and because the inguinal fold is high, it gives the appearance of a longer anterior thigh.

Baggy eyelids which are due in part to hypertrophy of the orbicularis oculi muscle may be corrected better if one includes a partial resection of the palpebral portion of this muscle. No eyelid paralysis or ectropion has occurred in our cases.

1. The non-radioactive cesium ion can replace the potassium ion almost quantitatively in solutions required for the development of the egg of the sea urchin into swimming blastulae. 2. Thorium chloride and uranium acetate cannot replace the potassium chloride in the solutions required for the development of the egg. 3. Thorium chloride and uranium acetate do not antagonize the action of the potassium contained in sea water upon the development of eggs.