Pulse arrival time, a novel sleep cardiovascular marker: the multi-ethnic study of atherosclerosis.

BACKGROUND: Pulse arrival time (PAT) is commonly used to estimate blood pressure response. We hypothesised that PAT response to obstructive respiratory events would be associated with increased cardiovascular risk in people with obstructive sleep apnoea. METHODS: PAT, defined as the time interval between electrocardiography R wave and pulse arrival by photoplethysmography, was measured in the Multi-Ethnic Study of Atherosclerosis Sleep study participants. The PAT response to apnoeas/hypopnoeas was defined as the area under the PAT waveform following respiratory events. Cardiovascular outcomes included markers of subclinical cardiovascular disease (CVD): left ventricular mass, carotid plaque burden score and coronary artery calcification (CAC) (cross-sectional) and incident composite CVD events (prospective). Multivariable logistic and Cox proportional hazard regressions were performed. RESULTS: A total of 1407 participants (mean age 68.4 years, female 47.5%) were included. Higher PAT response (per 1 SD increase) was associated with higher left ventricular mass (5.7 g/m2 higher in fourth vs first quartile, p<0.007), higher carotid plaque burden score (0.37 higher in fourth vs first quartile, p=0.02) and trended to greater odds of CAC (1.44, 95% CI 0.98 to 2.15, p=0.06). A total of 65 incident CVD events were observed over the mean of 4.1 (2.6) years follow-up period. Higher PAT response was associated with increased future CVD events (HR: 1.20, 95% CI 1.02 to 1.42, p=0.03). CONCLUSION: PAT is independently associated with markers of subclinical CVD and incident CVD events. Respiratory-related PAT response is a novel and promising polysomnography metric with cardiovascular implications.

Development of a pictorial scale for assessing functional interference with chronic pain: the Pictorial Pain Interference Questionnaire.

BACKGROUND: Assessment of function and functional interference is an important component of chronic pain assessment and treatment and is commonly based on self-report questionnaires. Existing questionnaires for assessing functional interference are language dependent, which can limit their utility for patients across cultures with literacy, fluency, or cognitive restrictions. OBJECTIVE: The objectives of this study were to create a tool with minimal language dependence and literacy requirement for measuring functional interference due to chronic pain and evaluate the psychometric properties and usability of this new assessment scale, the Pictorial Pain Interference Questionnaire (PPIQ), in a clinical sample of participants with chronic pain. DESIGN: The study employed a prospective, cross-sectional design in a clinical chronic pain setting. PARTICIPANTS AND METHODS: A total of 113 participants with chronic non-cancer pain were recruited from a private chronic pain clinic. A pictorial scale was developed and tested via psychometric procedures, including comparisons with validated measures of functional interference and related chronic pain constructs. RESULTS: Excellent internal consistency reliability (a=0.91), good construct validity (total score: r=0.72-0.81), and adequate-to-good convergent and discriminant validities were demonstrated through comparative analyses with existing self-report questionnaires. A scoring metric for classifying low, moderate, and high levels of interference was found to have good construct validity. Evaluation of satisfaction revealed adequate understanding of the PPIQ among most users. CONCLUSION: Initial support for the PPIQ as an alternative to language-based questionnaires for assessing functional interference from chronic pain was found. Subsequent research will help to clarify psychometric properties of the PPIQ and user response among various chronic pain subgroups.

An evaluation of a computer-imaging program to prepare women for chemotherapy-related alopecia.

OBJECTIVE: This study was conducted to evaluate a computer program named Help with Adjustment to Alopecia by Image Recovery (HAAIR) that was developed to provide educational support and reduce distress in women with hair loss following chemotherapy. METHODS: Forty-five women who had been diagnosed with cancer and anticipated alopecia following treatment were randomly assigned to either the Imagining group (IG) or Standardized Care group (SCG). Patients in the IG used a computer-imaging program that created the patient's image on a screen to simulate baldness and use of wigs whereas patients in the SCG were directed to a resource room at the Cancer Center established for women with chemotherapy-related alopecia. Assessment data using the Brief Symptom Inventory, Importance of Hair Questionnaire, and the Brief Cope were completed at baseline (T1), before chemotherapy and hair loss, following hair loss (T2), and 3 months follow-up (T3). RESULTS: All women were able to successfully use the touch screen computerized-imaging program and reported that using the computer was a positive, helpful experience, thus establishing acceptability and usability. Women in both the IG and the SCG group showed significantly lower hair loss distress scores at T2 after hair loss than at T1 with T3 distress scores increasing in the SCG and decreasing in the IG. Those with avoidance coping reported more distress. CONCLUSIONS: This evaluation demonstrates that the HAAIR program is a patient-endorsed educational and supportive complement to care for women facing chemotherapy-related alopecia.

Effectiveness of head-mounted vibrotactile stimulation in subjects with bilateral vestibular loss: a phase 1 clinical trial.

OBJECTIVE: Evaluate the effectiveness of a head-mounted vibrotactile prosthesis for balance improvement in subjects with severe bilateral vestibular loss (BVL). STUDY DESIGN: Crossover study. SETTING: Academic tertiary care vestibular function test center. PATIENTS: Five subjects with severe BVL as defined by video-oculography, rotational chair, and computerized dynamic posturography criteria. INTERVENTION: Vibrotactile head tilt feedback MAIN OUTCOME MEASURES: Change in Sensory Organization Test (SOT) Conditions 5 and 6 performance (fall-no fall, time to fall, strategy analysis) and dynamic subjective visual vertical (DSVV) response. RESULTS: 1) Significant improvement in binary fall-no fall ratio on SOT 5 and SOT 6 combined (chi2 = 9.603, df = 1, p = 0.001); 2) Significant increase in time to fall measurements on SOT 5 (p < 0.001) and SOT 6 (p < 0.01; 1-tailed t test); 3) Nonsignificant improvement in strategy scores on SOT 5 (p = 0.156) and SOT 6 (p = 0.259; 1-tailed t test); and 4) No significant effect during eccentric DSVV testing (analysis of variance). CONCLUSION: Head-mounted vibrotactile stimulation produced significant improvement in postural stability in subjects with BVL undergoing SOT 5 and 6 testing with no effect on subjective visual vertical during DSVV testing.

A new approach to assessing function in elderly people.

Current functional assessment methods and measures of elderly people are limited in their ability to detect small decrements in function or in discriminating between different patterns of functional loss. Nor do they directly assess function in the patient's usual environment. Recent technological advances have led to the development of small, wearable microelectronic devices that detect motion, velocity and acceleration. These devices can be used to develop new tools for more precise monitoring, assessment, and prediction of function by characterizing the 'electronic signatures' of successful or unsuccessful task-specific performance, and to allow for continuous assessment in a home environment. This presentation will summarize current efforts to translate new technologies into a clinical and research tool for improved assessment, monitoring, and prediction of function among older individuals.

The use of polynomial neural networks for mortality prediction in uncontrolled venous and arterial hemorrhage.

BACKGROUND: The ability to rapidly and accurately triage, evacuate, and utilize appropriate interventions can be problematic in the early decision-making process of trauma care. With current methods of prehospital data collection and analysis, decisions are often based upon single data points. This information may be insufficient for reliable decision-making. To date, no studies have attempted to utilize data at multiple time points for purposes of enhancing prediction, nor have studies attempted to synthesize prediction models with data reflecting both large-vessel venous and arterial injuries. Therefore, we performed a retrospective study to examine the potential utility of dynamic neural networks in predicting mortality using highly discretized uncontrolled hemorrhagic shock data. METHODS: One hundred forty-three swine with either grade V liver injuries or 2.8-mm aortotomies had hemodynamic data collected every minute throughout injury and resuscitation. The independent variables used as inputs to the polynomial neural networks (PNNs) included systolic blood pressure and mean arterial pressure (MAP). These inputs were used to predict mortality in individual swine 1 hour after injury using data up to 20 minutes after injury. Survival models were compared based on discrimination power (DP), i.e., where specificity equals sensitivity, and area under the receiver operating characteristic (ROC) curve (c-statistic). The Hosmer-Lemeshow (H-L) statistic was used to measure model calibration. RESULTS: The best PNN model predicted mortality at 60 minutes utilizing data from injury to 20 minutes after injury. This model produced a ROC area of 0.919, a DP of 0.857, and a H-L value of 16.47. A DP of 0.857 means that 85.7% of the survivors are correctly predicted to survive, and 85.7% of the nonsurvivors are predicted to die. MAP of survivors and nonsurvivors were graphed for comparative purposes. As this graph illustrates, the use of MAP alone cannot discriminate survivors from nonsurvivors. CONCLUSION: This study demonstrates that PNN models can effectively harness the dynamic nature of uncontrolled hemorrhagic shock data, despite utilizing data from large-vessel arterial and venous injuries. Utilizing the dynamic nature of hemorrhagic shock data in PNNs may ultimately allow the development of novel decision assist devices.