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Biomedical subjects

W R Marshall

Publications and source records attributed to W R Marshall.

16 recordsLinked to original sources
PubMed1994

The PB3300 intraarterial blood gas monitoring system.

Continuous intraarterial blood gas (IABG) monitoring is in clinical use both in the operating room and intensive care unit. This technology uses miniature, optically-based sensors that can be placed into a patient's artery. The arterial blood gas values are transduced into an optical signal that is measured by a bedside monitor on which the values are displayed. In this paper, we describe the operating principles of the PB3300 Intra-Arterial Blood Gas Monitoring System (Puritan-Bennett Corporation, FOxS Division, Carlsbad, CA). Topics include the principles of fluorescent determinations of pH, PCO2, and PO2; the optical path of the PB3300; system calibration; dye layer geometry; and clinical operation. The accuracy, precision, and drift of the system measuring tonometered aqueous standards are reported. The following values were noted for eight sensors sending data to eight monitors: system bias and precisions of 0.00 +/- 0.02 pH at a pH of 7.40, -2.5 +/- 1.5 mm Hg PCO2 at a PCO2 of 40 mm Hg, and 3.3 +/- 1.3 mm Hg PO2 at a PO2 of 80 mm Hg.

Blood Gas Analysis↗
PubMed1992

Misdiagnoses: a timely reminder.

This case report of an occult infection masquerading as palindromic arthritis was misdiagnosed for almost 2 years. The episodic bouts of erysipelas were not obvious, and it was even suggested that the silicone implanted 7 years previously could possibly be inciting an autoimmune disease. Approximately 2 years after the onset of the recurrent episodes of fever, myalgias, and arthralgias, coagulase-negative staphylococci were found residing in the valve stems of bilumen breast implants, which were removed. The symptom complex disappeared and has not recurred.

Adult↗
PubMed1989

Types of collagen in breast capsules.

Representative sections of the capsules that envelop surgically implanted silicone were analyzed for their collagen content. The specimens were biopsied (as incidental procedures) as the opportunities arose. All four classes of capsules as codified clinically and those surrounding tissue expanders are represented. The ages of the capsules ranged from 6 weeks to 13 years. Eighteen specimens were examined by slab gel electrophoresis. Type I collagen predominated in all of the electrophoretic patterns. Type III collagen was consistently present in lesser concentrations. Type V collagen was consistently present as a small fraction. There was no evident correlation between the concentrations of the component collagens and the clinically assessed class of the capsules or of those from around tissue expanders, but there was a correlation to the age of the capsules. The electrophoretic patterns of the collagens of this study are indistinguishable from the (previously reported) analyses of (cutaneous) scar.

Adult↗
PubMed1986

Amelioration of capsular contracture by motion restriction.

Surgical augmentation of the female breast has become a well-accepted and frequently performed operation since the introduction of the Cronin Silastic mammary prosthesis in 1963. A sleeve of scar tissue (collagenous capsule) consistently develops around every silicone implant. This "reactive bursa" is the normal healing response to this unique foreign body, and should not be referred to as a complication. It actually supports the prosthesis and contours the augmented breast. Operative technique includes precautions to prevent particulate or microbial contamination. Postoperative management involves restriction of motion of and around the mammary implant. (I realize this is a departure from currently accepted techniques. The methods presented, however, are based on physiologic principles of wound healing.) The results for all (private practice) patients who underwent augmentation mammaplasty during the four-year period of 1980 through 1983 were evaluated and codified. They suggest that the incidence of capsular contracture of the augmented breast can be decreased by taking precautions to ameliorate the foreign body reaction to silicone.

Adolescent↗
PubMed1984

The efficacy of personalized audiovisual patient-education materials.

Patient education is considered an important component of primary care medicine. The traditional methods of patient education have been physician-patient dialogue and printed handouts. This study compares the relative efficacy of pamphlets, one-to-one dialogue, and audiovisual presentations. The results indicate that the slide and sound presentation was most effective in conveying patient information.

Adult↗
PubMed1982

Chondrolysis complicating slipped capital femoral epiphysis.

In a detailed study of 249 patients, 329 cases who had slipped capital femoral epiphysis treated at the Campbell Clinic during the period from 1935 to 1973, chondrolysis was found in 79 hips in 71 patients (28.9%). The incidence of chondrolysis is correlated with the number of factors, including sex, race, chronicity and severity of displacement, and method of treatment. On the basis of biopsy observations upon 23 patients who had chondrolysis, the natural history of the disease includes self-perpetuating synovitis, and progresses with abnormal mechanical stress on the articular cartilage and the development of osteoarthritis.

Cartilage Diseases↗
PubMed1978

Effect of heart-rate control training on heart-rate discrimination.

4 subjects were exposed to discrimination-testing procedures before and later biofeedback training to increase and decrease their heart rates. Results indicated significant increases and decreases in heart rate, as well as a significant improvement in accuracy of discrimination. The results suggest improvements in discrimination may occur as a function of feedback training.

Biofeedback, Psychology↗
PubMedDate not supplied

A study of the effectiveness of oral midazolam as a dental pre-operative sedative and hypnotic.

Orally administered Midazolam at dosages of 0.5, 0.6, and 0.75 mg/kg was used with 34 healthy, uncooperative pediatric dental patients. Effective pre-operative sedation occurred within approximately 15 minutes with a 30- to 40-minute duration of action. Blood pressure and respiration remained stable throughout. The numbers and types of procedures performed were dependent on the degree of sedation, the behavior of the patient, the experience of the operator, and the operator's ability to administer the medication. The ideal dosage appears to be 0.6 mg/kg, with an average change of 1.43 Frankel Units in behavior modification. A dosage of 0.5 mg/kg appears to yield erratic results, while a dosage of 0.75 mg/kg offers little advantage with greater potential for adverse reactions. The oral administration of Midazolam for pediatric patients with extreme behavioral problems, such as Attention Deficit Hyperactive Disorder, was of little advantage and may produce an idiosyncratic reaction. Midazolam's quick onset and short duration of action, coupled with its ideal properties of sedation, relaxation, and amnesia, offer a viable alternative for treating the anxious, uncooperative pediatric dental patient.

Administration, Oral↗