PubMed Health⌕ Search

Biomedical subjects

W M O'Brien

Publications and source records attributed to W M O'Brien.

At least 55 records · Page 3Linked to original sources
PubMed1980

Comparison of high and low dose cyclophosphamide therapy in rheumatoid arthritis.

Eighty-eight patients with active rheumatoid arthritis from 8 Cooperating Clinics were evaluated in a 32-week controlled, double-blind trial comparing 150 mg daily to 75 mg cyclophosphamide daily. Improvement in the arthritis was seen in both groups, and there were no important differences between the two treatment groups in any of the 8 variables used to measure disease activity. Untoward effects were also similar for the two groups. These results differ from preliminary results reported earlier.

Adult↗
PubMed1980

Diagnosis, not energy or weight, determines ventricular defibrillation.

In a study demonstrating 95% success in achieving defibrillation in 94 resuscitative events in adult patients, the authors find that weight did not determine that success and that the results were obtained at significantly low rates of energy output. Diagnosis was the key, they conclude, and they view the expensive high-energy defibrillators marketed today as unnecessary, potentially lethal, and economically wasteful.

Body Weight↗
PubMed1979

Energy levels and patient weight in ventricular defibrillation.

In a prospective survey employing conventional devices that stored 400 joules or less, direct-current shocks that delivered 194 +/- 11 joules (1.8 joules/kg) to the chest wall terminated 45 of 46 episodes of ventricular fibrillation in 11 of 12 patients weighing 91 to 225 kg. Patients with coronary disease defibrillated more easily than patients without coronary disease. Weight did not determine outcome. The 98% defibrillation efficiency occurred at only half the energy predicted for 50% efficiency from retrospective data. Human defibrillation not only occurred at one third the untested level recommended by proponents of high-energy defibrillation, but also at one fourth the energy, defibrillating 69% of comparably heavy animals. Thus, the costly defibrillators delivering 400 to 800 joules now sold by 11 of 14 American manufacturers are superfluous, untested, potentially lethal devices with which to attempt ventricular defibrillation.

Adolescent↗
PubMed1979

Determinants of ventricular defibrillation in adults.

Conventional defibrillators which stored no more than 400 J and used damped sine wave pulses defibrillated 240 of 253 (95%) episodes of ventricular fibrillation (VF) in 94 prospectively assessed resuscitations in 88 adults. Shocks of 80--240 J (under 3 J/kg) delivered to the chest wall defibrillated more often than higher energy levels. Defibrillation rate did not correlate with weight. Defibrillation was determined by the diagnosis and setting in which VF occurred. Patients with acute myocardial infarction (AMI) and primary VF or with coronary disease and no AMI defibrillated more easily than patients with AMI and secondary VF or with no coronary disease. VF in a terminal patient (agonal VF) defibrillated less often than VF in other clinical situations. Age, weight, delivered energy, duration of pulse wave, and duration of VF had little, if any, influence on rate of defibrillation. These data fail to support the use of more expensive, high-output defibrillators sold by 11 or 14 American manufactures.

Adult↗
PubMed1978

Accuracy of Gram's stain in identifying pneumococci in sputum.

We prospectively examined the accuracy of Gram-stained sputum for identifying pneumococci in 42 patients with community-acquired pneumonia. We considered the Gram's stain positive if a preponderant flora or more than ten Gram-positive lancet-shaped diplococci were seen per oil immersion (x1,000) field. These criteria were met in 18 (62%) of 29 specimens that actually contained pneumococci as determined by a positive quellung reaction, or culture on plates or in mice. The Gram's stain was negative in 11 of 13 specimens that did not contain pneumococci. Of the 20 specimens yielding positive Gram's stains, 18 contained pneumococci. A positive Gram-stained smear of sputum strongly suggests the presence of pneumococci, but will miss 38% of specimens containing pneumococci. Deviation from these criteria substantially reduces the overall accuracy of the test.

Acute Disease↗
PubMed1977

Patient survival and instrument performance with permanent cardiac pacing.

Among 313 patients who received cardiac pacemakers between 1961 and 1973, there was a 65% survival rate after five years, a progressive decrease in premature pulse generator failures, and a low, stable incidence of electrode malfunction. Decreased survival among more recently paced patients was attributed to an evolution of the selection for pacing that favored older patients with associated diseases. Death due to unexpected pacing failure was extremely rare. Premature pulse generator failures decreased from 0.8 per 100 pacing months among early units to 0.06 per 100 months among units implanted during 1971 to 1973, when a prophylactic replacement policy was in effect. Electrode revisions were required at a frequency of 0.5 to 0.8 per 100 months in both epicardial and endocardial systems. Electrode failures may limit the predictive value of surveillance systems, since these rely on a change of pacing frequency or pulse width to indicate battery depletion.

Adult↗
PubMed1977

Pharmacokinetics of amoxicillin: dose dependence after intravenous, oral, and intramuscular administration.

Amoxicillin was studied in normal subjects after intravenous, oral, and intramuscular administration of 250-, 500-, and 1,000-mg doses. Serum drug levels were analyzed using a two-compartment open model, as well as area under the curve (AUC) and urinary recovery. The variations of these pharmacokinetic parameters were then examined using the three-way analysis of variance and linear regression equations. These results confirmed nearly complete oral absorption: AUC was 93% of intravenous absorption, and urinary recovery was 86%. The intramuscular administration of amoxicillin results in complete and reliable absorption with peak drug levels, AUCs, and urinary recovery equivalent to oral dosage. The absorption of lyophilized amoxicillin after intramuscular injection resulted in an AUC that was 92% of intravenous absorption and urinary recovery of 91%. The peak serum levels, time to peak, and other pharmacokinetic parameters for intramuscular injection were nearly identical to those for oral administration. Kinetics of both intramuscular and oral administration exhibited dose-dependent absorption (absorption rate constant, 1.3/h for 250 mg and 0.7/h for 1,000 mg). This resulted in relatively later and lower peak serum levels for increasing dose. Total absorption, however, showed no dose dependence, as indicated by urinary recovery and AUC, which changed by less than 10%.

Administration, Oral↗
PubMed1977

Double-blind, multi-centre parallel trial of ketoprofen and ibuprofen in the treatment of rheumatoid arthritis.

A double-blind parallel multi-centre study of 102 patients with rheumatoid arthritis (RA) was performed, comparing ibuprofen (1200-2400 mg daily) and ketoprofen (150-300 mg daily) a new non-steroidal, anti-inflammatory agent, over a three month period. Ketoprofen was well tolerated and shown to have comparable efficacy with ibuprofen. Longterm efficacy and tolerance studies are indicated.

Adult↗