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Biomedical subjects

P Appel

Publications and source records attributed to P Appel.

At least 19 recordsLinked to original sources

Prospective trial of supranormal values as goals of resuscitation in severe trauma.

We prospectively tested the effect of the early postinjury attainment of supranormal values of cardiac index (> or = 4.52 L/min per square meter), oxygen delivery (> or = 670 mL/min per square meter), and oxygen consumption (> or = 166 mL/min per square meter) on outcome in traumatized patients with an estimated blood loss of 2000 mL or more. The goals in control patients were to attain normal values for all hemodynamic measurements. During the 6-month period, 33 protocol patients and 34 control patients with similar vital signs, estimated blood losses, and severity of injuries were enrolled in the study. Eight (24%) protocol patients died, while 15 (44%) control patients died. The protocol patients had fewer mean (+/- SEM) organ failures per patient (0.76 +/- 1.21 vs 1.59 +/- 1.60), shorter stays in the intensive care unit (5 +/- 3 vs 12 +/- 12), and fewer mean days requiring ventilation (4 +/- 3 vs 11 +/- 10) than did the control patients (P < .05 for each). We conclude that attaining supranormal circulatory values improves survival and decreases morbidity in the severely traumatized patient.

Adolescent

Alcoholism and methadone treatment: consequences for the patient and program.

The data on alcoholism presented in this paper were extracted from a major follow-up study of active and discharged methadone patients conducted from 1974 through 1977 in New York City. Alcoholism is a factor in 26% of the terminations from methadone treatment. It is also the leading cause of death in treatment and the second leading cause of death, following complications with opiates, in the post-treatment Also, patients with episodes of excessive drinking have markedly lower survival rates over a 10-year period when compared to patients who are social or moderate drinkers.

Actuarial Analysis

Superiority of transcutaneous oximetry in noninvasive vascular diagnosis in patients with diabetes.

Transcutaneous oxygen tension Ptco2 is directly related to skin oxygen delivery. Regional transcutaneous oximetry ( RTO ) compares peripheral and truncal (Ptco2), yielding a regional perfusion index indicative of local limb perfusion. The relative diagnostic values of RTO , Doppler ankle-brachial pressure ratio (ABR), pulse volume recording (PVR), and toe pulse reappearance time (PRT/2) were studied in 64 limbs of patients with diabetes. These limbs were clinically classifiable into claudication, rest pain, and gangrene groups. Regional transcutaneous oximetry had a higher diagnostic accuracy than ABR (X2 = 27.47, P less than .001), PVR (X2 = 7.54, P less than .01), and PRT/2 (X2 = 10.99, P less than .001). Regional transcutaneous oximetry was universally applicable and the degree of hypoxia observed correlated with clinical symptoms. Significant hypoxia predicted large-vessel angiographic lesions, many of which were reconstructible . Regional transcutaneous oximetry should be the initial noninvasive test in diabetic peripheral vascular disease.

Aged

Assessment of perfusion in the diabetic foot by regional transcutaneous oximetry.

Regional transcutaneous oximetry is a new, noninvasive diagnostic technique for the investigation of peripheral vascular disease (PVD) that uses differences in limb and trunk transcutaneous PO2 to assess the adequacy of local perfusion. The application of such measurements would be of great importance in diabetes, in which limb ischemia is commonly difficult to assess. A group of diabetic subjects with symptomatic PVD was studied with regional oximetry, Doppler-assisted blood pressure measurements, and arteriography. Doppler studies correlated poorly to symptom grade and angiographic data, while oximetry clearly demonstrated limb hypoxia under the functional conditions appropriate to the patients' clinical symptomatology. The superiority of oximetry to Doppler studies was highly significant (X2 = 12.64, P less than 0.001). Regional transcutaneous oximetry should therefore be the noninvasive diagnostic test of choice in the initial evaluation of the diabetic limb for PVD. Because of its dependence on the adequacy of local oxygenation, transcutaneous oximetry is a powerful tool for investigation of the pathophysiology of PVD and will, in the future, have wide-ranging applications to the diagnosis and therapy of PVD.

Aged

The State perspective.

Our survey showed that State agencies make use of NIDA materials of all sorts, including NIDA treatment evaluation materials. A majority of the respondents indicated that NIDA treatment evaluation materials were among the most useful of its products; most frequently mentioned was DARP, then Nurco's and Robins' work, and TOPS. That DARP was most frequently mentioned is not a contradiction, since the responses were stated in a general sense, not in terms of a specific report or material. In the past 1 to 2 years, many State drug abuse agency budgets have been substantially reduced due to declines in Federal funding. As a result, treatment evaluation reports and related materials are viewed somewhat differently than they were in the past. The fiscal climate in various States may thus be another factor contributing to the greater familarity and reported use of reports such as DAWN, CODAP, and case management and monitoring manuals published by NIDA. A number of suggestions were made about the kinds of evaluation materials needed by States. It was generally agreed that attempts should be made to produce treatment evaluation findings/new knowledge in a format where it would be more accessible to administrators (e.g., "how-to" manuals, evaluation case studies, dissemination of treatment evaluation bibliographies) and should assist in making existing treatment evaluation results more accessible (divide results for modalities into subtypes, provide data on the effectiveness of specific interventions with specific conditions, diversify the settings of programs in which evaluations are done, etc.). The theme of these various suggestions is to make evaluations more available, usable, and specific, especially now in view of the reduced ability of many States to carry on their own evaluation activities. The general sense of the respondents regarding dissemination was that right now, in view of other problems such as the financial crunch, NIDA's system of distribution cannot be a salient concern. Nevertheless, from a State perspective, NIDA's dissemination of treatment evaluation materials is particularly important in the light of the paucity of resources States have to conduct their own research. Thus, having access to NIDA's usable evaluation data is all the more crucial to improving service delivery and its cost effectiveness. Another factor to bear in mind at the present time is the absence of opportunities to share evaluation results at national conferences which formerly were, of course, major mechanisms for formal dissemination.

Government

Pathophysiologic classification of peripheral vascular disease by positional changes in regional transcutaneous oxygen tension.

The clinical manifestations and prognosis of peripheral vascular disease (PVD) depend upon the severity of limb hypoxia. Transcutaneous oxygen tension (Ptco2) is related to tissue oxygenation, but limb Ptco2 varies with changes in systemic as well as peripheral oxygen delivery (Do2). Previously we have found that simultaneous assessment of limb and chest Ptco2 yields a ratio, or regional perfusion index (RPI), that is independent of systemic Do2 and accurately reflects the adequacy of limb perfusion. Analysis of segmental limb Ptco2, RPI, and position-induced RPI changes was performed in 24 control limbs and 14 limbs with intermittent claudication (IC), 8 limbs with rest pain (RP), and 7 limbs with gangrene (G). Control limbs had high RPI values that varied little with position. The IC group had modestly decreased RPIs in the supine position, but extremity RPIs decreased markedly during leg elevation. Patients with RP had ischemia while supine, but the RPI improved to nearly normal upon standing. Feet with G were hypoxic even in the standing position. Segmental RPI decreases correlated with the presence of significant arterial lesions. This correlation was unaffected by diabetes. Analysis of regional transcutaneous oximetry allows classification of PVD by quantitative criteria based upon the adequacy of limb perfusion under functional conditions. RPI is characteristically high in normal persons and low in persons with G. Limbs with marginally compensated perfusion may have nearly normal RPI values under some conditions, but typical ischemic changes are elicited by positional change and exercise. The ease of such provocation of RPI decreases constitutes an index of the severity of disease. Such quantitative assessments of limb hypoxia can form the basis for a physiologic approach to arterial reconstruction.

Aged

Use of physiologic monitoring to predict outcome and to assist in clinical decisions in critically ill postoperative patients.

A predictive index based on cardiorespiratory-monitored values of an earlier series of postoperative critically ill patients was tested in prospective clinical trials and found to be reasonably accurate, sensitive, and specific. The hypothesis was tested that the median values of patients who survived life-threatening postoperative conditions, rather than the norms of unstressed, healthy volunteer subjects, constitute a first approximation to the optimal therapeutic goals for critically ill postoperative patients. In a prospective series of 223 consecutive, critically ill postoperative patients, normal values were used as the therapeutic goals of the control patients, whereas the median values of surviving patients were used as the goals of therapy for the protocol group. The clinical conditions of the protocol group were at least as severe as those of the control group, but the mortality was significantly less in the protocol group (12.5 percent) than in the control group (35 percent); the number of life-threatening complications were also greater in the control group. These data suggest that at least half and possibly as much as two thirds of postoperative deaths may be due to physiologic problems that can be identified, described, predicted, and prevented. Therapy for the critically ill patient should be defined by physiologic criteria, and administration of therapy should be monitored to attain prophylactically optimal physiologic goals rather than giving therapy after a deficiency has occurred to attain normal values.

Clinical Trials as Topic

Factors affecting the intracellular generation of free radicals from quinones.

Isolated hepatocytes do not liberate appreciable amounts of superoxide into the external medium. Simple quinones stimulate the release of superoxide up to 15 nmol/min/10(6) hepatocytes. Superoxide release stimulated by a variety of simple quinones and more complex antitumor quinones was maximal at a quinone one-electron reduction potential of -70 mV. This was qualitatively similar to the pattern of superoxide formation seen with NADH-cytochrome b5 reductase and NADH: ubiquinone oxidoreductase. Superoxide production by NADPH-cytochrome P-450 reductase was maximal at a quinone single-electron reduction potential at -200 mV. Phenobarbital pretreatment had no effect on superoxide formation by hepatocytes suggesting that NADPH-cytochrome P-450 reductase activity is not rate limiting for quinone stimulated superoxide formation. Sulfonated stilbenes, specific inhibitors of anion exchange, had no effect on the release of superoxide by hepatocytes suggesting that superoxide is not transported through anion channels in the plasma membrane. Pretreatment of hepatocytes with 10(-5) M diethyldithiocarbamate produced over a two fold increase in the release of superoxide.

Animals

Pathogenesis of respiratory failure (ARDS) after hemorrhage and trauma: I. Cardiorespiratory patterns preceding the development of ARDS.

To evaluate clinical and physiologic determinants of adult respiratory distress syndrome (ARDS), we studied 152 consecutively monitored patients with trauma and hemorrhage: 60 developed ARDS. The cardiorespiratory patterns of hemorrhage and trauma patients who did not develop ARDS were compared to those who subsequently did develop ARDS, but before the time of their ARDS. Comparisons also were made in the patients with trauma and those with hemorrhage, as well as in those who survived and those who did not. Hemorrhage and trauma patients who developed ARDS had greater reductions in blood volume, red cell mass, PaCO2 and O2 delivery throughout all stages, as well as greater pulmonary vascular resistance index (PVRI) and pH in the early and middle stages. Nonsurvivors of ARDS had greater deficits in blood volume and red cell mass, higher PVRI and pH, as well as lower central venous pressure (CVP), hemoglobin (Hgb), and PaCO2 than did ARDS survivors. Hemorrhage patients had lower blood volume, left ventricular function, O2 delivery and VO2, as well as higher systemic vascular resistance index (SVRI), PVRI, and O2 extraction than either the trauma patients or normal subjects. Description of the temporal cardiorespiratory patterns before the clinical appearance of ARDS showed the progressive appearance of these deficits beginning 36 h before the hypoxemia was observed. The data are consistent with the concept that ARDS after hemorrhage and trauma is preceded by hypovolemia, reduced myocardial performance, inadequate O2 delivery, and inadequate O2 extraction needed to maintain VO2 at the elevated levels demanded by the increased metabolic requirements of the injured patients. Thus, the so-called shock lung is a complication of shock associated with hypovolemia, hypoxemia, and inadequate cardiac compensatory responses to increasesd O2 demands.

Female

Pathogenesis of respiratory failure (ARDS) after hemorrhage and trauma: II. Cardiorespiratory patterns after development of ARDS.

Hemodynamic and oxygen transport variables were studied in a series of 60 patients who sustained adult respiratory distress syndrome (ARDS) from hemorrhage and trauma; measurements were made during the period of their ARDS and in survivors after their recovery from ARDS. In general, cardiac index (CI) and myocardial performance were increased over normal values; they were greater in trauma patients than in hemorrhage patients and greater in the survivors than in nonsurvivors. The mean pulmonary artery pressure (MPAP) and pulmonary vascular resistance index (PVRI) were high in all groups. Blood volume and hemoglobin (Hgb) concentrations were reduced especially in the nonsurviving hemorrhage patients; hemoglobin saturation (SaO2) and oxygen tension (PaO2) were low initially, but usually responded to therapy; oxygen consumption (VO2) was normal or high in all groups, and was greater in survivors than in nonsurvivors, and greater in trauma than in hemorrhage. Thus, the patient with post-traumatic ARDS has circulatory and metabolic needs which are greater than normal values defined by values from healthy unstressed volunteers and also somewhat greater than hemorrhage and trauma patients without ARDS. Optimal blood volume, hemodynamic and oxygen transport values defined by the survivor's values as well as the standard respiratory care are recommended as goals for preventive or ealy therapy of these patients. Volume therapy should be given provided it does not elevate the pulmonary arterial wedge pressure (WP) above 18 mm Hg to avoid overloading the pulmonary vascular bed and causing pulmonary edema.

Female