Anesthetic action of opiates: correlations of lipid solubility and spectral edge

The ability of opiates to be a complete anesthetic has been assessed in animals. These studies have investigated the serum levels of opiate required to produce a decrease in anesthetic requirement for a concomitantly administered inhalation anesthetic. A linear dose-response relation has been observed between opiate serum level and reduction in anesthetic requirement up to the level of 50% reduction in minimum alveolar anesthetic concentration (MAC). These studies have not demonstrated the production of one MAC anesthesia by the opiates. Recent EEG studies have provided another means of comparing the central nervous system effects of opiates and inhalation anesthetics. The serum levels of several opiates associated with a 50% reduction (IC50 or 50% inhibitory concentration) in maximal spectral edge frequency (SEF) have been reported. The free, unionized serum levels of each opiate at IC50 in humans or 50% MAC reduction in animals are remarkably similar. We calculated brain lipid opiate content at these serum levels using available physiochemical data. The calculated nanogram and molar brain lipid contents of the drugs fell within a 10-fold range while serum levels varied by 5000-fold. This similarity in membrane lipid content in association with EEG and anesthetic effects suggests that opiate "anesthesia" may involve a membrane effect in addition to the well established receptor interaction.     

Feasibility analysis for medical services.

Feasibility analysis is an important aspect of business planning. A feasibility study is a study of the impacts of revenues, cost, and returns on a decision. It helps answer the questions of "What share of total sales can be attained?" "What revenues will be generated?" "What costs will be incurred?" "What will be the return on investment?" The discipline of going through a systematic approach to analyze market demand, cost requirements, and return on investment will improve business decisions by eliminating risk and increasing the possibility of successful ventures.     

Attitudes toward prevention of cardiovascular diseases among first-year students at eight American medical schools, 1983-1985

First-year medical students at eight U.S. medical schools were surveyed by written questionnaire in 1983-1985 to determine their attitudes toward cardiovascular diseases prevention at medical school entry. An overall response rate of 92% was achieved (2,654 questionnaires), and 97% of responders provided complete and analyzable survey data. Response rates at five of eight medical schools were 98-100%, and one school each had rates of 67, 84, or 90%. Differences in mean attitude responses from school to school were small, as were differences between men and women or between blacks and whites. This survey found that entering medical students have generally positive attitudes toward the effectiveness of preventive cardiology practice as well as toward the importance of research efforts in cardiovascular disease prevention. Students frequently indicated, however, that it is "extremely difficult" to change patients' unhealthful habits and that "physician encouragement" may not be sufficient to help patients achieve more healthful behaviors. These findings could be helpful in directing educational efforts for medical students. The data suggest that major emphasis should be placed on conveying facts regarding the physicians' efficacy in clinical preventive cardiology and on teaching the skills of preventive cardiology practice. Less emphasis appears to be necessary on encouraging positive attitudes about the importance of prevention since current students' attitudes appear to be already positive in this dimension.     

Measuring visual neglect in acute stroke and predicting its recovery: the visual neglect recovery index.

An overall measure of the recovery of visual neglect in patients with an acute stroke is described: The "Visual Neglect Recovery Inde" (VNRI) expresses the amount of visual neglect on a battery of visual neglect tests as a percentage of complete recovery from the maximal visual neglect measurable. The principles underlying the development of the index are similar to those involved in the development of the Motricity Index for hemiplegia. A population of 68 survivors of stroke who presented with visual neglect at two to three days were followed for up to six months. The VNRI showed that neglect was greater in those with right hemisphere stroke than in those with left hemisphere stroke and that recovery was most rapid over the first 10 days and reached a plateau at three months. Most patients, including many with severe initial visual neglect, showed little visual neglect at three months. Stepwise regression analysis showed that the severity of visual neglect at three months and at six months post-stroke could be predicted by the severity of visual neglect and the presence of anosognosia at two to three days. A regression equation was produced which may enable clinicians to select patients for intensive treatment of visual neglect.     

An update on digoxin

This review deals briefly with recent developments in the therapeutic drug monitoring of digoxin. Strategies for decreasing the interference by digoxin metabolites, digoxin-like factors, and spironolactone metabolites in immunoassays of digoxin are discussed. Other issues addressed include the development of alternative methods of analysis, such as receptor assays and "high-pressure" liquid chromatography; digoxin-like factors in hypertension; drug-drug interactions; redistribution of digoxin stores in the body; and forensic considerations.     

Effects of lung hyperinflation on mean arterial pressure and postsuctioning hypoxemia

Our purpose was to determine the effect of five different lung hyperinflation volumes (tidal volume, 12 cc/kg, 14 cc/kg, 16 cc/kg, and 18 cc/kg lean body weight) on mean arterial pressure and postsuctioning hypoxemia (arterial blood gases). Subjects received three consecutive lung hyperinflations at one of the five randomly ordered volumes in 15 seconds via a ventilator "sigh" control at a fraction of inspired oxygen of 1.0. The three lung hyperinflations were followed by 10 seconds of continuous suction (flow rate 16 L/min). The procedure was repeated three times. The sample consisted of eight men and women 4 hours after coronary artery bypass graft surgery. Data indicated a statistically significant (by analysis of variance, p = 0.000) mean increase of 15 mm Hg in mean arterial pressure over the three lung hyperinflation sequences that was not volume dependent. There was a significant increase (p = 0.0001) in arterial oxygen pressure at 0 seconds after suctioning that increased with each increasing lung hyperinflation volume.     

Individual psychotherapy with victims of incest

In treating victims of incest, therapists need to be aware of the gamut of symptoms, personality traits, interpersonal difficulties, and clinical syndromes that occur with special frequency in this population. A list of these features is provided. Vignettes with typical therapist-patient dialogue are offered, demonstrating techniques for handling the initial consultation and opening phase of treatment. During later phases of treatment the focus will usually shift to the discussion of the pertinent symptoms (such as suicidal feelings, substance abuse, dissociative phenomena, sexual disturbances, and distorted self-image). Further on, therapy will focus on abnormal personality traits and attitudes that the incest experience may have set in motion. Examples include mistrustfulness, jealousy, seductiveness, hostility, impulsivity, defiance and emotional volatility. Many incest victims develop borderline personality disorder. Highly polarized attitudes ("splitting") toward sexual partners are characteristic of this group. Therapy relies upon supportive, re-educative, and interpretive work designed to help the victim develop more realistic and integrated views of self and other.     

Transdermal scopolamine decreases nausea and vomiting following cesarean section in patients receiving epidural morphine

The authors evaluated the antiemetic properties of transdermal scopolamine (TDS) in healthy patients undergoing elective cesarean section and receiving epidural morphine for postoperative analgesia. Prior to administration of anesthesia, 203 patients had either TDS or a placebo study patch applied behind one ear. All patients were hydrated with lactated Ringer's solution iv and given 2.0% lidocaine with 1:200,000 epinephrine epidurally for surgical anesthesia. Following delivery of the infant, 4 mg of morphine sulphate was injected through the epidural catheter. After the operation patients were evaluated by "blinded" observers at 2, 4, 6, 8, 10, 24, and 48 h for nausea, vomiting, retching, pain relief, itching, and adverse effects. In addition, medications received were noted. No differences were found between the groups in terms of severity or incidence of pain, or requests for analgesic or antipruritic medication. Although there was no difference between the groups in the first 2 h, patients with TDS had significantly less nausea, vomiting, and retching than patients in the placebo group in each time interval between 2 and 10 h. Additionally, the TDS group required less antiemetic medication. There was no difference in the frequency of retching or vomiting between groups. Side effects were minimal and equal in both groups. The authors conclude that TDS results in a decreased incidence of nausea and vomiting in patients who have delivered by cesarean section and received epidural morphine. TDS appears safe for continuous antiemetic administration.