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Biomedical subjects

R M Kaplan

Publications and source records attributed to R M Kaplan.

At least 163 records · Page 9Linked to original sources

The relationship between cynical hostility and blood pressure reactivity.

It is hypothesized that high levels of hostility stimulate blood pressure hyperresponsivity to challenge. Seventy-six normotensive adults completed the MMPI hostility subscale, and blood pressure reactivity to, and recovery from, cold pressor and mental arithmetic stressors were measured on two occasions. Only one of twenty Pearson correlations between Cook-Medley hostility and blood pressure reactivity was significant. Analyses of variance revealed that blood pressure reactivity was influenced by sex and family history of cardiovascular disease, but neither factor interacted with hostility. There was no evidence from the present study that cynical hostility as measured by the Cook-Medley was associated with blood pressure reactivity.

Adult↗

Aggregation of blood pressure in Anglo-American and Mexican-American families.

We investigated the aggregation of blood pressure within 95 Anglo-American and 111 Mexican-American families. Degree of genetic relatedness was evaluated by calculating separate correlations for spouses and for each spouse with both same-sex and opposite-sex offspring. In addition, sibling correlations were evaluated. These analyses were performed separately for Anglo-American and Mexican-American families. Replicating earlier findings, correlations between blood pressures of Anglo spouses were nonsignificant. However, there were significant spousal correlations in the Mexican-American group. For Anglo-American families, there were significant associations between blood pressures of fathers and sons and between blood pressures of mothers and daughters. Correlations between blood pressures for opposite-sex parent-child pairs were nonsignificant. In the Mexican-American group, there were significant correlations between fathers' blood pressures and those of both male and female offspring. For mothers, blood pressures were weakly correlated with all other family members. These relationships remained after adjustment for age, body mass index, and measures of dietary habits and activity levels. In general, blood pressure aggregation was greater in Mexican-American families.

Adult↗

Selective attrition causes overestimates of treatment effects in studies of weight loss.

Selective attrition causes serious threats to the validity of experimental trials. Experimental studies in behavior therapy typically include only data from those who complete an experiment. In this paper, we examine the probability of dropping out of a study contingent upon failure to achieve desired benefits. The data are derived from an experimental trial evaluating the effects of weight loss for patients with Diabetes Mellitus. Seventy-six percent of the original participants completed the intervention and the follow-up assessments. However, the probability of failing to appear for follow-ups over an 18 month period was examined. The chances of dropping out of the study were significantly higher for those who did not achieve a goal of weight reduction. This selective loss to follow-up results in an overestimate of treatment effectiveness. By failing to acknowledge drop-outs, treatment failures may be systematically eliminated from the analyses.

Adult↗

Methemoglobin levels following intravenous lidocaine administration.

Methemoglobin levels were obtained before and after administration of IV lidocaine in 40 cardiac patients. Patients were given a 1-mg/kg bolus of IV lidocaine hydrochloride, started on a maintenance infusion at 2.0 mg/min, and given a second bolus of lidocaine of 0.5 mg/kg 15 minutes after the initial bolus. The maintenance infusion was adjusted from 1 to 4 mg/min according to clinical needs. Methemoglobin levels were drawn at zero, one, and six hours, and lidocaine levels were drawn at one and six hours after the initial bolus. Elevation of methemoglobin levels after lidocaine administration was statistically significant (P less than .05), but not clinically significant. The highest methemoglobin level obtained was 1.2%. Only one other patient had a level above 1%. No patient developed either signs of lidocaine toxicity or toxic levels of methemoglobin. Routine determination of methemoglobin levels is not clinically indicated following routine lidocaine administration. It may have some as-yet-undetermined value in lidocaine-toxic patients.

Adult↗

Effect on the seizure threshold in dogs of tocainide/lidocaine administration.

Oral lidocaine analogues, such as tocainide, recently have been introduced to treat cardiac arrhythmias. The side effects of tocainide are similar to those of lidocaine, but possible interactions with lidocaine have not been examined thoroughly. With the increased use of these agents, emergency physicians must decide the safety of concurrent administration of lidocaine for local anesthesia or arrhythmia management. Twelve dogs were assigned randomly to either a lidocaine (L) or a tocainide/lidocaine (TL) group. The L group received lidocaine at a dosage of 0.5 mg/kg/min until the animals seized. The TL group received both loading and maintenance doses of tocainide to obtain therapeutic steady-state tocainide levels prior to receiving lidocaine at a dosage of 0.5 mg/kg/min. Venous blood samples to measure drug levels were obtained at 20-minute intervals and at the time of seizures. The average duration of lidocaine administration required to induce seizures in the L group was 70.0 +/- 7.5 minutes, and in the TL group 29.0 +/- 7.0 minutes (P less than .05). In addition, the average serum lidocaine level at the time of seizures was 11.2 +/- 1.0 micrograms/mL in the L group and 6.2 +/- 1.7 micrograms/mL in the TL group (P less than .05). Our results show that in animals the presence of a therapeutic serum level of tocainide lowers the seizure threshold following the administration of lidocaine. These findings may have important implications for clinical care because they suggest that lidocaine should be used cautiously and in reduced dosage in patients already taking tocainide.

Animals↗

Differential effects of social support and social network on physiological and social outcomes in men and women with type II diabetes mellitus.

Patients with non-insulin-dependent diabetes mellitus (NIDDM) were advised to comply with a complex behavioral regimen of diet and exercise. The relationship between social support satisfaction and social support network size was evaluated using the Social Support Questionnaire for 32 men and 44 women with a confirmed diagnosis of NIDDM. Control of diabetes, as measured by the glycosylated hemoglobin assay, was significantly correlated with social support satisfaction for women but negatively correlated with social support satisfaction for men. Social support network size differentially predicted success in a program for men and women. For women, network size was significantly correlated with failure to attend sessions and with failure to complete a diary. For these women, network size was not significantly correlated with weight loss, which was the goal of the program. For men, network size was correlated with increases in weight, cholesterol, and triglycerides over an 18-month period. We conclude that social support network size and satisfaction have different functions for men and women faced with a serious chronic illness. Network size adversely affects success in a program, whereas social support satisfaction has some benefits for women. The direction of the influence of social network may be determined by the similarity or dissimilarity of network norms to the desired behavior.

Adult↗

Metered-dose aerosolized bronchodilators in prehospital care: a feasibility study.

The prehospital use of aerosolized bronchodilators was studied in 50 adult patients with bronchospasm. The specific beta 2-agonist, albuterol, was discharged from a metered-dose inhaler (MDI) into the Inhal-aid reservoir-delivery device. No serious adverse effects were encountered, although a substantial proportion of the patients (36%) had difficulty utilizing the device. Ability to use the system properly correlated with improvement in symptoms; inability to use the device was most clearly related to severity of clinical presentation. It is concluded that the use of aerosolized bronchodilators is feasible in prehospital care and most useful in patients with mild or moderately severe symptoms.

Administration, Inhalation↗

Success rates of blind orotracheal intubation using a transillumination technique with a lighted stylet.

The technique of guided orotracheal intubation using a lighted stylet depends on the transillumination of the soft tissues of the neck to direct the tube through the glottis and into the trachea. We conducted an operating room study of this technique, recording success rates and intubation times of 50 patients undergoing elective surgery. All patients were intubated successfully, 35 of 50 (70%) on the first attempt, 12 of 15 (80%) on the second attempt, and three of three (100%) on the third attempt. The average time for intubation was 37 seconds. A new design of the lighted stylet method resulted from the experience gained. Intubator training and experience influenced initial success rates, and the cadaver laboratory was of particular value in teaching the technique.

Adolescent↗

Methemoglobin levels following sublingual nitroglycerin in human volunteers.

Sublingual nitroglycerin 0.8 mg every five minutes for a total of 4.8 mg was administered to 11 healthy volunteers. One volunteer had to withdraw due to a hypotensive bradycardic reaction after 2.4 mg. In the remaining subjects, methemoglobinemia over the next hour never significantly increased from baseline levels, reaching a peak of only 0.71%. We conclude that commonly used doses of sublingual nitroglycerin do not induce significant methemoglobinemia and that nitroglycerin would not be useful in the treatment of cyanide poisoning.

Adult↗

Transcutaneous pacing for bradyasystolic cardiac arrests in prehospital care.

To test the efficacy of transcutaneous pacing in prehospital bradyasystolic arrest, we applied an external transcutaneous pacing device to patients with asystole, pulseless idioventricular rhythms (PIVR), and pulseless bradycardias. Pacemaker units were carried by emergency medical services (EMS) physicians and specially trained EMS personnel. Patients were followed to determine hospital course and outcome. Of the 112 patients evaluated, information to adequately document the presence or absence of electrical capture was available in 105 cases. Fifty-five (52%) of these cases demonstrated electrical capture; 9 of 112 patients (8%) recovered pulses. Of those in asystole, 26 of 50 (52%) showed electrical capture, while the rate was 60% for those with PIVR (24 of 40 patients) and complete heart block (CHB) (3 of 5 patients), and 25% for other pulseless bradycardias (2 of 8 patients). Pulses developed following capture in five of 55 patients (9%) in asystole and in four of 44 patients (9%) with PIVR. No patient with CHB or other bradycardias developed a pulse. No patients survived to be discharged from the hospital. The average time to application of the pacing device was 29 minutes after loss of pulse. Our data strongly suggest that delayed use of the transcutaneous pacing device does not improve the dismal survival rates of patients who suffer bradyasystolic cardiac arrest. Further studies should be directed toward investigating survival rates in patients paced immediately after the onset of cardiac arrest.

Aged↗

Acute effects of oxygen treatment upon information processing in hypoxemic COPD patients.

The present study investigated the effects of oxygen therapy upon human information processing for hypoxemic COPD patients. Each of ten patients was admitted to a general clinical research center for a two-day period. In a randomly counter-balanced factorial design, patients breathed either room air or enriched oxygen for either six hours or 20 minutes prior to testing. The tests evaluated speed of information processing, ability to detect correct sequence of tones, and serial memory. In addition, patients were evaluated on critical flicker fusion and story recall. The results suggested that acute oxygen therapy does not reverse information processing deficits observed in hypoxemic COPD patients.

Aged↗

Validity of a quality of well-being scale as an outcome measure in chronic obstructive pulmonary disease.

This paper evaluates the validity of the Quality of Well-being Scale (QWB) as an outcome measure for research on Chronic Obstructive Pulmonary Disease (COPD). The Quality of Well-being Scale was originally designed for use as a general health outcome measure. One criticism of this approach has been that it may not be valid in studies limited to a specific disease or condition. We report correlations between the QWB and a variety of other outcome measures obtained in an experimental trial evaluating the benefits of behavioral programs for COPD patients. The data from the trial suggest that the QWB is substantially correlated with both performance and physiological variables relevant to the health status of COPD patients. An advantage of the QWB is that it can be transformed into well-year units for cost-effectiveness studies. It is concluded that the QWB has many advantages as an outcome measure for specific disease groups.

Cost-Benefit Analysis↗