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Biomedical subjects

I L Cohen

Publications and source records attributed to I L Cohen.

At least 37 records · Page 2Linked to original sources
PubMed1993

Anxiety and the interpretation of ambiguity: a text comprehension study.

Beck's influential cognitive account of anxiety has led to the prediction that individuals vulnerable to anxiety should favor threatening interpretations of ambiguity (e.g., Beck & Clark, 1988; Beck, Emery, & Greenberg, 1986). The current study introduces a novel adaptation of the RSVP technique, previously used in text comprehension research, to evaluate this hypothesis. Results suggest that a group of 24 high trait anxious students did indeed selectively impose threatening interpretations on unconstrained ambiguous sentences. In contrast, a matched group of 24 low trait anxious students appeared to selectively impose non-threatening interpretations on such ambiguous sentences. These findings are fully consistent with the predicted anxiety-linked interpretative bias. Specific testable hypotheses are developed concerning the types of interpretative idiosyncrasies that plausibly may contribute to pathological anxiety.

Adolescent↗
PubMed1993

The effects of ventilator working pressure during pressure support ventilation.

The purpose of this study was to examine the consequences of altering ventilator working pressure on airway pressure and flow characteristics during pressure support ventilation (PSV). A ventilator (Siemens Servo 900C) and single lung simulator were used, and graphic read outs, in triplicate, were taken at a variety of combinations of PSV, working pressure, lung compliance, and airway resistance. The graphic read outs were then analyzed for a number of "dependent variables," and multiple regression analyses were performed using working pressure, PSV level, compliance, and resistance as "independent variables." The results show that the relative impact of working pressure on airway pressure and flow will vary with other lung and airway characteristics; also, excessive working pressure results in significantly greater flow rates at 40 ms after onset of inspiratory flow and at maximum flow, greater ringing or overshoot in the circuit, reduced tidal volume and inspiratory time, and reduced area under the airway pressure curve. In conclusion, adjusting ventilator working pressure will significantly affect lung-ventilator interaction in a quantifiable fashion. Further, these findings support clinical evidence that working pressure and/or initial flow rate need to be individualized to ensure optimal airway flow and pressure characteristics.

Airway Resistance↗
PubMed1993

"Pseudo auto-PEEP"? A new cause for discrepancy between the end-expiratory occlusion plateau pressure and airway opening pressure.

The purpose of this study is to describe an unexpected degree of differences between expiratory occlusion plateau pressure (EPO) and airway opening pressure (Pawo) measured level of intrinsic positive end-expiratory pressure above externally applied (auto-PEEP) that was found in six critically ill patients. In six patients (ten studies), the presence and degree of auto-PEEP found during the EPO maneuvers was not confirmed by Pawo measurements. In five studies, flow tracings showed prolonged near zero flow toward end expiration and a slow rise to plateau during the EPO maneuver. Because of the static nature of the EPO determination, a rise in pressure could conceivably be caused by the presence of subcutaneous or mediastinal emphysema and retrograde flow across the airway defect during exhalation. We suggest another cause for auto-PEEP-dynamic hyperinflation from extrapulmonary flow limitation.

Adult↗
PubMed1993

Establishing and justifying specialized teams in intensive care units for nutrition, ventilator management, and palliative care.

The team concept should be better appreciated and used as a tool for managing or solving problems in the ICU. If teams are designed improperly or employed inappropriately, however, they can easily fragment care and interfere with efficiency. Formally rounding with three or four teams a day is bound to lead to chaos and is impractical, but the team can be used to generate multidisciplinary protocols that reduce the need for formal face-to-face interaction. The team also can be convened when problems arise. In all three areas discussed in this article, specific teams were carefully formed in response to perceived problems in patient care. A great deal of attention was paid to determining the problems, and approaches were designed to resolve them in the most expedient manner possible. The results reported from all three types of teams are impressive. The team approach also has an unmeasured beneficial effect on staff morale. Although much of this discussion is intuitive, it must be emphasized that the types of interactions described in this article and the resulting positive outcomes happened not by accident, but by careful and conscious design. More research is needed in critical care areas to best define how to optimize the use of personnel. After all, volumes of data are generated on drugs, technologies, and other medical issues that often show little, if any, impact on outcome. The human component of the ICU is by far the most valuable and expensive commodity; we can ill afford to misapply it.

Clinical Protocols↗
PubMed1992

Recurrent Pseudomonas aeruginosa pneumonia in an intensive care unit.

We reviewed the records of all patients in the intensive care unit (ICU) who had Pseudomonas aeruginosa pneumonia over a 2.5-year period. Of patients with P aeruginosa pneumonia, 20 of 34 survived the initial episode of pneumonia. Ten of these 20 developed recurrence. In the nonrecurrent group, nine of ten survived hospitalization, compared to only four of ten in the recurrent group. Comparing the recurrent to the nonrecurrent group, factors associated with recurrence were the APACHE 2 score (12.3 +/- 2.7 vs 8.6 +/- 4.2 [p less than 0.03]), APS score (7.0 +/- 3.5 vs 2.7 +/- 2.1 [p less than 0.01]), and chronic pulmonary disease (8/10 vs 2/10 [p less than 0.05]). The recurrent P aeruginosa group was younger (63 +/- 10 vs 74 +/- 11 years old [p less than 0.03]) and spent more time receiving mechanical ventilation (95 +/- 64 vs 26 +/- 36 days [p less than 0.01]), in the ICU (101 +/- 61 vs 33 +/- 35 days [p less than 0.01]), and in the hospital (144 +/- 77 vs 84 +/- 32 days [p less than 0.03]). Although not statistically significant, in the recurrent group, eight of ten patients had tracheostomy and seven of ten had COPD, vs three of ten and two of ten, respectively, in the nonrecurrent group. Recurrent P aeruginosa pneumonia in the ICU is associated with increased morbidity and mortality and does not appear to be related to the adequacy of antibiotic treatment. Chronic lung disease appears to predispose patients to recurrent P aeruginosa pneumonia.

Adult↗
PubMed1992

Fick-derived hemodynamics. Oxygen consumption measured directly vs oxygen consumption calculated from CO2 production under steady state and dynamic conditions.

Indirect calorimetry is being used increasingly as a tool for hemodynamic monitoring via the Fick equation. This investigation was undertaken to examine the use of carbon dioxide elimination (VCO2A) and related respiratory quotient (RQA) to calculate oxygen uptake (VO2A) and estimate oxygen consumption (VO2) during steady-state and dynamic hemodynamic conditions. Nine patients undergoing abdominal aortic surgery were studied intraoperatively and Fick-derived hemodynamic measurements were made using a monitoring system employing indirect calorimetry, pulse oximetry, and pulmonary artery oximetry. Comparisons were made between measured VO2A and calculated VO2A derived from the VCO2A and the initial RQA (RQi), which is assumed not to change. Prior to aortic crossclamping (steady state), there were no significant differences between the measured and calculated methods with respect to oxygen consumption (184 +/- 24 ml/min vs 185 +/- 17 ml/min), oxygen delivery (753 +/- 141 ml/min vs 769 +/- 178 ml/min), and cardiac output (4.7 +/- 0.6 L/min vs 4.7 +/- 0.7 L/min). However, immediately following aortic unclamping (dynamic state), the RQA changed precipitously from the baseline RQi. Consequently, significant differences between the measured and calculated methods were noted in oxygen uptake (213 +/- 41 ml/min vs 193 +/- 25 ml/min, p < 0.001), oxygen delivery (780 +/- 297 ml/min vs 716 +/- 296 ml/min, p < 0.001), and cardiac output (5.8 +/- 2.2 L/min vs 5.3 +/- 1.8 L/min, p < 0.001). Additionally, following unclamping, the peak VO2A was 242 +/- 49 compared with a cVO2A of only 198 +/- 22 (p < 0.01). We conclude that the use of VCO2A to calculate VO2A may lead to erroneous measurements under dynamic conditions, such as unclamping of the abdominal aorta.

Aorta, Abdominal↗
PubMed1991

Clinical utility and cost-effectiveness of protective sleeve pulmonary artery catheters.

OBJECTIVE: To assess the clinical utility of protective sleeves in pulmonary artery (PA) balloon flotation catheters. DESIGN: Prospective, randomized trial with cost-effectiveness analysis. SETTING: A general adult ICU in a community teaching hospital. PATIENTS: All patients receiving PA balloon flotation catheters over a 1-yr period. INTERVENTIONS: Groups 1 and 2 received PA catheters with and without protective sleeves, respectively. Indications for catheter changes, other than catheter malposition, were the same for both groups. MEASUREMENTS AND MAIN RESULTS: In group 1, 54 patients received 71 catheters and four catheters were replaced due to the inability to obtain a PA occlusion pressure (PAOP) tracing. In group 2, 48 patients received 66 catheters, 11 of which were inserted due to failure to obtain a PAOP (p less than .05). PA catheters were repositioned successfully in 37/56 attempts in group 1, compared with 8/20 attempts in group 2 (p less than .05). There was no significant difference in complication rates between the two groups. Even at the increased cost of the protective sleeves and introducer ($7/kit), for 100 catheter insertions, we project a direct cost savings of $742, and personnel time savings of 10.5 hrs for physicians, 14 hrs for nurses, and 4.7 hrs for radiology technicians. CONCLUSION: Protective sleeves on PA catheters are safe, effective, cost-saving devices for ICU patients.

Aged↗
PubMed1991

Reduction of duration and cost of mechanical ventilation in an intensive care unit by use of a ventilatory management team.

OBJECTIVE: To test the hypothesis that a formal interdisciplinary team approach to managing ICU patients requiring mechanical ventilation enhances ICU efficiency. DESIGN: Retrospective review with cost-effectiveness analysis. SETTING: A 20-bed medical-surgical ICU in a 450-bed community referral teaching hospital with a critical care fellowship training program. PATIENTS: All patients requiring mechanical ventilation in the ICU were included, comparing patients admitted 1 yr before the inception of the ventilatory management team (group 1) with those patients admitted for 1 yr after the inception of the team (group 2). Group 1 included 198 patients with 206 episodes of mechanical ventilation and group 2 included 165 patients with 183 episodes of mechanical ventilation. INTERVENTION: A team consisting of an ICU attending physician, nurse, and respiratory therapist was formed to conduct rounds regularly and supervise the ventilatory management of ICU patients who were referred to the critical care service. MEASUREMENTS AND MAIN RESULTS: The two study groups were demographically comparable. However, there were significant reductions in resource use in group 2. The number of days on mechanical ventilation decreased (3.9 days per episode of mechanical ventilation [95% confidence interval 0.3 to 7.5 days]), as did days in the ICU (3.3 days per episode of mechanical ventilation [90% confidence interval 0.3 to 6.3 days]), numbers of arterial blood gases (23.2 per episode of mechanical ventilation; p less than .001), and number of indwelling arterial catheters (1 per episode of mechanical ventilation; p less than .001). The estimated cost savings from these reductions was $1,303 per episode of mechanical ventilation. CONCLUSION: We conclude that a ventilatory management team, or some component thereof, can significantly and safely expedite the process of "weaning" patients from mechanical ventilatory support in the ICU.

Aged↗
PubMed1991

Continuous hemodynamic monitoring: an integrated invasive-noninvasive approach using the Fick principle.

This paper reviews a continuous integrated computer based approach to monitoring oxygen supply (DO 2) and consumption (VO 2) relationships. A description of the technologic methodology and potential advantages over intermittent thermodilution monitoring are discussed. Lastly, the preliminary results of investigations in two populations (abdominal aortic surgery and adult respiratory distress syndrome) are presented.

Animals↗
PubMed1991

Why are autism and the fragile-X syndrome associated? Conceptual and methodological issues.

Investigations of the association between autism and the fragile-X syndrome have yielded conflicting results with some studies indicating a strong correlation and others indicating no relation between the disorders. In this paper, we review the relevant research on this controversy and discuss the conceptual and methodological problems involved in such an inquiry. We conclude that autism and fragile X are associated and that this relation will prove fruitful in understanding the role of the X chromosome in a variety of behavior disorders and in unraveling various theoretical accounts on the etiology of autism.

Autistic Disorder↗
PubMed1990

Conversational analyses of males with fragile X, Down syndrome, and autism: comparison of the emergence of deviant language.

Deviant, repetitive language of 33 males (9 with Down syndrome, 12 with fragile X (fra[X]) syndrome, and 12 with autism) was analyzed within three conversational contexts: direct responses, initiation of new material, and topic maintenance. Results indicated that males with fra(X) manifest deviant, repetitive language that is distinct from males with either Down syndrome or autism. Thus, the deviant repetitive language of males with fra(X) cannot be accounted for by either their level of adaptive functioning or autistic-like behaviors per se. Possible explanations for this etiologically specific language deviance were discussed.

Adolescent↗
PubMed1989

Parent-child dyadic gaze patterns in fragile X males and in non-fragile X males with autistic disorder.

Parent-child dyadic gaze patterns were examined in fragile X [fra(X)] males and in non-fra(X) autistic males across three age groups--early childhood, middle childhood and adolescence. Absolute probabilities of social gaze did not significantly differ across diagnostic groups. Event lag sequential analyses indicated that fra(X) males were sensitive to social gaze initiation by their parents but found eye contact aversive. Non-fra(X) autistic males, by contrast, were insensitive to parent-initiated social gaze, and did not find eye contact aversive. Implications for research on the social characteristics of fra(X) and autistic children are discussed.

Adolescent↗