Determination of the electrical axis of the heart.

The rapid, accurate determination of the electrical axis of a patient's heart is very useful for diagnosis. This determination can be made readily by using six electrocardiographic leads. The procedure for interpreting the data from these leads and determining the electrical axis of the heart is charted.

Repetitive elastance measurement as a means of recording pharmacological responses in vascular smooth muscles.

We describe a method of recording pharmacological responses in isolated arterial segments, based on the direct measurement of vascular wall elastance. The segment outflow is intermittently occluded, and the elastance determined from the subsequent pressure-flow relationship. Since the measurement cycle can be repeated 12 times per minute, rapid pharmacological responses can be studied.

Human T lymphotropic virus type I-associated myelopathy. A report of 10 patients born in the United States.

Human T lymphotropic virus type I (HTLV-I)-associated myelopathy (HAM) (tropical spastic paraparesis/HAM) has rarely been reported in the United States. We present 10 well-documented cases with positive Western immunoblot test results and polymerase chain reactions for HTLV-I. The clinical and laboratory features of these American-born patients resemble those previously reported series of tropical spastic paraparesis and HAM from the Caribbean and Japan, but important differences were observed.

Measurement of arterial blood pressure during anaesthesia.

Regular measurement and recording of blood pressure, with pulse monitoring and ECG, are the 'minimal monitoring' without which no anaesthetic should take place. This is because blood pressure is an index of some of the most fundamental physiological processes.

Dual-chamber cardiac pacemakers.

Dual-chamber cardiac pacing provides distinct advantages over single-chamber systems, namely atrioventricular synchrony, improved cardiac output, and prevention of pacemaker syndrome. Providing nursing care to patients with dual-chamber pacemakers demands an understanding of basic cardiac pacing and of the unique features of dual-chamber systems. This knowledge is essential in evaluating pacemaker function, relating it to the patient's condition, and intervening appropriately in the face of complex paced rhythms.

Interactive videodisc as an instructional tool in medical education.

At a time when medical educators are actively revising the undergraduate medical school curriculum to make it more responsive to exigencies of the 21st century, the use of interactive videodisc technology may well prove to be a significant addition. Using interactive videodisc technology may be instrumental in reducing the amount of a large lecture didactic learning and improving small group problem-solving sessions that better synthesize factual knowledge. It also provides important and valuable exposure to varieties of computer technology that play an increasingly important role in training and medical practice.

A preliminary investigation of the consequences that define the mand and the tact.

Skinner (1957) proposed that the mand and the tact differed with respect to their unique antecedents and consequences. The present study examined the specific reinforcement characteristic of the mand, and the nonspecific reinforcement characteristic of the tact. A severely mentally impaired individual who used sign language served as subject.

Trichomonas gallinae in columbiform birds from the Galapagos Islands.

Domestic pigeons were introduced into the Galapagos Islands in 1972 or 1973. There is a high prevalence of Trichomonas gallinae among them and some evidence of canker. Trichomonas gallinae can be found also in endemic Galapagos doves in the vicinity of Puerto Ayora on Santa Cruz Island.

Monitoring patients with permanent cardiac pacemakers.

Patients requiring cardiac pacing are predominantly older citizens with multiple problems, demanding highly skilled monitoring as well as a holistic approach to their care. Pacemaker therapy, though widely accepted, currently is being scrutinized to determine its impact on cost as well as quality. To this end, a Joint American College of Cardiology/American Heart Association Task Force established a subcommittee on pacemaker implantation to define current indications for permanent cardiac pacemakers.

Pacemaker malfunction: fact or artifact?

In summary, the present examples illustrate how pacemaker malfunction can be simulated by the sources of artifact produced or detected by the monitoring equipment. This form of pseudopacemaker malfunction remains a common cause of mistaken diagnosis of pacemaker malfunction. A thorough understanding of the examples outlined above should help distinguish true pacemaker malfunction from pseudopacemaker malfunction produced by artifact.

Incremental propofol for short procedures.

Propofol was used to induce and maintain anaesthesia in patients undergoing minor gynaecological procedures. Quality of anaesthesia, the rate of recovery and the influence of different methods of premedication were assessed. Unpremedicated patients required a higher induction dose than those premedicated with either lorazepam or papaveretum and hyoscine, but maintenance dose requirements were comparable.

An office laboratory panel to assess vaginal problems.

In determining the cause of vaginal complaints, the routine use of four simple tests ("the vagina panel") enables the physician to identify pathogens (Candida, Gardnerella, Trichomonas), pathologic processes (inflammation, estrogen deficiency) and, in most instances, a healthy vagina. Time and money are saved. The specimens can be collected in one minute during a pelvic examination.

Rehabilitation techniques for athletic injury.

In summary, the application of principles of rehabilitation to athletic injury includes efforts directed at reducing swelling and pain while maintaining the range of motion. As the range of motion increases, efforts are made to regain strength while the patient is protected from reinjury and from the stresses of returning to function.

Hamstring/quadriceps ratios in college football players: a high velocity evaluation.

Hamstring/quadriceps ratios were assessed on 60 intercollegiate football players at functional speeds of 90, 180, and 300 deg/sec on the Cybex II. The ratio rose as velocity of exercise increased and the quadriceps was stronger than the hamstrings at all speeds. The flexor/extensor ratio differed bilaterally at all speeds with ratio lower for the dominant knee.

Ventrolateral medullary surface blood flow determined by hydrogen clearance.

The H2 clearance technique was used to determine the blood flow of the postulated respiratory chemosensitive areas near the ventrolateral surface of the medulla. In 12 pentobarbital sodium-anesthetized cats, flow (mean +/- SD) was measured from 25-micron Teflon-coated platinum wire electrodes implanted to a depth of 0.3-0.

Ventilatory depression related to plasma fentanyl concentrations during and after anesthesia in humans.

Twenty-four patients were allocated randomly into four groups for the study of the pharmacokinetics of, and effects on postoperative ventilation of, two doses of fentanyl (10 micrograms/kg or 25 micrograms/kg) administered at the start of general anesthesia in which ventilation was controlled at a fixed volume, but arterial PCO2 was adjusted to a range of either 38-42 torr, or 20-25 torr. During the first 2 hr after anesthesia, ventilatory depression (CO2 responsiveness decreased to less than 50% of awake values, PaCO2 greater than 48 torr) occurred only in patients who had received 25 micrograms/kg fentanyl, and was more marked in patients who were hyperventilated to a low PaCO2 during anesthesia. Plasma fentanyl concentrations associated with 50% depression of CO2 responsiveness were in the range 1.

Colonization of Candida albicans in vagina, rectum, and mouth.

To better understand the frequency of appearance, the density of growth, and the most common sites in which female patients harbor Candida albicans, a study was initiated of all patients receiving a pelvic examination for any reason at a solo family practice office. From February 1980 to November 1981, 341 pelvic examinations were accompanied by cultures and colony counts of the vagina, rectum, and mouth. A semiquantitative method adapted to Microstix-Candida (Ames Company) was utilized.