PubMed Health⌕ Search

Biomedical subjects

J Olson

Publications and source records attributed to J Olson.

At least 109 records · Page 6Linked to original sources
PubMed1992

Intravenous conscious sedation use in endoscopy: does monitoring of oxygen saturation influence timing of nursing interventions?

Knowledge of oxygen saturation and the timing of nursing interventions were studied for their relationship to positive patient outcomes in a group of patients receiving intravenous conscious sedation during endoscopy. The convenience sample consisted of 38 patients receiving midazolam or a combination of midazolam/fentanyl during esophagogastroduodenoscopy or colonoscopy in a hospital-based endoscopy unit. Data collection included monitoring oxygen saturation levels, physiological parameters, and skin color. Baseline arterial oxygen saturation was obtained and monitored continuously throughout the procedure and during the recovery period. During the procedures, the nurse was aware of the oxygen saturation levels for half of the subjects. For the other subjects, the nurse was informed only when the oxygen saturation dropped below 85%. Data revealed a clinically significant relationship between knowledge of oxygen saturation and the timing of nursing interventions in effecting positive patient outcomes during endoscopic procedures. The results of this pilot study contributed to the development of standards of care for monitoring oxygen saturation in an endoscopy unit. The timeliness of nursing interventions was enhanced by the use of pulse oximetry, thereby producing positive patient outcomes and improving the quality of care for the endoscopic patient receiving conscious sedation.

Aged↗
PubMed1991

The case for the single case report.

A case of unusual variant of a Meckel's diverticulum containing multiple enteroliths has been described. Although in this case, probably no clinical symptoms were present, it is obvious that hemorrhage, inflammation or obstruction could occur in the future. In this case, removal was definitely indicated.

Aged↗
PubMed1991

Cerulein-induced pancreatitis in the ex vivo isolated perfused canine pancreas.

Infusion of supramaximal doses of the cholecystokinin analog cerulein is well established as an in vivo technique for inducing experimental pancreatitis in small animals. An attempt was made to simulate this model and initiate pancreatitis in the ex vivo isolated perfused canine pancreas. Control preparations gained minimal weight (mean 8.3 +/- 5.1 gm), demonstrated no edema accumulation, and did not develop hyperamylasemia (mean 1342 +/- 790 units) after 4 hours of perfusion. Electron microscopy after 4 hours of perfusion remained normal. Intraarterial cerulein infusion produced significant weight gain (mean 27.6 +/- 12.3 gm; p less than 0.001), edema formation, and marked hyperamylasemia (mean 26,838 +/- 21,341 units; p less than 0.001) after 4 hours of perfusion. During the 4-hour perfusion, electron microscopy of cerulein preparations demonstrated depletion of zymogen granules, condensing vacuole formation, and basolateral exocytosis. Pretreatment of cerulein preparations with the free radical scavengers superoxide dismutase and catalase and the iron chelator deferoxamine did not modify the pancreatitis. Continuous infusion of the nonpeptide cholecystokinin antagonist L364,718 reduced cerulein-induced weight gain (4.3 +/- 3.4 gm; p less than 0.001) and hyperamylasemia (9392 +/- 6718 units; p less than 0.05). We conclude that cerulein pancreatitis in the ex vivo isolated perfused canine pancreatic preparation is identical physiologically, biochemically, and morphologically with that seen in intact animals.

Acid-Base Equilibrium↗
PubMed1990

[Significance of trans-esophageal echocardiography as an adjunct to transthoracic echocardiography].

We describe our experience with the first 103 patients undergoing transesophageal echocardiography at our institution. The procedure was well accepted by most patients and associated with no major complications. The clinical indications for this procedure have included endocarditis, prosthetic cardiac valve dysfunction, detection of intracardiac source of embolism, atrial septal defect and thoracic aortic dissection. Transesophageal echocardiography proved to be useful in all of these diagnostic categories, especially if standard transthoracic echocardiography did not provide a complete assessment.

Adult↗
PubMed1990

Hamman-Rich syndrome revisited.

In this article, we retrospectively review 29 cases of Hamman-Rich syndrome. As in some other recent reports, we have used the term "acute interstitial pneumonia" to emphasize the clinical and pathologic features of these cases and to distinguish them from the more common chronic interstitial pneumonias, particularly idiopathic pulmonary fibrosis. Of the 29 patients, 12 survived, some after a long and complicated hospitalization. The histologic features were those of organizing diffuse alveolar damage, and some patients, including survivors, had extensive fibroblastic distortion of lung parenchyma. The overall survival among these patients was not appreciably different from the survival of patients with the adult respiratory distress syndrome in general.

Acute Disease↗
PubMed1990

SMRFIT: a Statistical Analysis System (SAS) program for standardized mortality ratio analyses and Poisson regression model fits in community disease cluster investigations.

Increasingly, health departments are being pressed by the public to respond to disease risk with cluster investigations in communities and neighborhoods. This is a direct result of growing concern about the role that the environment may play in disease risk. While extensive analyses directly inputing exposures or numbers at risk are often necessary to thoroughly investigate clusters, it is quite useful to perform an exploratory analysis with existing morbidity and mortality data as a first level of response. To meet this need for timely evaluation, the authors describe a user-friendly Statistical Analysis System (SAS) program called SMRFIT to automate community disease cluster evaluations. The program creates frequency tables for number at risk and number of disease outcomes for the community, balance of parent county, and balance of state. SMRFIT then constructs standardized mortality ratios, with the community compared with balance of county and balance of state referents. Poisson regression is offered as an option for the modeling of community disease rates.

Adult↗
PubMed1990

Multiple-dose pharmacokinetics of oral zidovudine in hemophilia patients with human immunodeficiency virus infection.

The disposition of zidovudine (ZDV) was examined during chronic oral dosing (300 mg every 4 h while awake) for 12 weeks in eight asymptomatic patients with hemophilia who were infected with the human immunodeficiency virus. Pharmacokinetic studies were conducted at the initiation of drug administration and after 6 and 12 weeks. Baseline liver function tests indicated normal values for bilirubin, albumin, and prothrombin time, while hepatic enzyme levels ranged from one to three times the normal levels. Initially, the mean peak ZDV concentration in plasma was 2,052 ng/ml with a range of 1,033 to 3,907 ng/ml, while during chronic dosing the peaks were 1,619 +/- 1,062 ng/ml and 1,711 +/- 786 ng/ml at weeks 6 and 12, respectively. ZDV concentrations at 4 h declined to 77 +/- 53 ng/ml, 110 +/- 43 ng/ml, and 101 +/- 49 ng/ml at weeks 1, 6, and 12, respectively. Initially, the plasma concentration-versus-time decay in three patients was linear, with a mean half-life (t1/2) of 1.3 +/- 0.5 h, while five patients had detectable concentrations in plasma after 4 h with an apparent delayed terminal-phase t1/2 of 4.8 +/- 2.8 h. At week 6 the prolonged elimination pattern was noted in all patients (terminal t1/2 = 4.1 +/- 2.0 h). No correlation between hepatic enzyme levels and t1/2 was noted. These findings suggest that ZDV may display a prolonged elimination phase during multiple dosing. Further studies utilizing a more sensitive assay may help to further define this later phase of ZDV elimination.

Administration, Oral↗
PubMed1989

Pharmacokinetics of orally administered zidovudine among patients with hemophilia and asymptomatic human immunodeficiency virus (HIV) infection.

Zidovudine (formerly azidothymidine, AZT) is used to treat certain patients infected with the human immunodeficiency virus (HIV). However, the clinical use of zidovudine (ZDV) in hemophilia patients may be complicated by the high incidence of chronic hepatitis in this patient population. To examine the pharmacokinetics of ZDV eight asymptomatic HIV-infected hemophilia patients received a single oral dose (300 mg). ZDV and its glucuronide metabolite (GZDV) were measured in serum by HPLC. ZDV was rapidly absorbed with a wide range of peak serum concentrations (2052 +/- 970 ng/ml) at 0.5 h. Peak GZDV serum concentrations were 4751 +/- 2269 ng/ml at 1 h. Both ZDV and GZDV declined in a biexponential manner over 4 h. After 4 h, the ZDV serum concentration decay in three patients continued a log-linear decline, while five patients demonstrated a tri-exponential curve which had a mean terminal elimination half-life of 4.8 +/- 2.8 h. No relationship between ZDV or GZDV kinetics and the degree of hepatic enzyme elevation was observed. Although a therapeutic window for ZDV has yet to be described, the wide range of serum concentrations that result from a standard dose suggests that clinical monitoring of ZDV levels may be of value in certain patients. In addition, the prolonged elimination half-life of ZDV in the present study may provide a rationale for less frequent dosing in certain patients.

Administration, Oral↗
PubMed1988

Selenium treatment in neuronal ceroid-lipofuscinosis.

Neuronal ceroid-lipofuscinosis (NCL) refers to a group of disorders with devastating effects on the central nervous system. The accumulation of autofluorescent lipopigments containing lipid peroxides is considered a pathogenetic mechanism of the cell damage seen in NCL. Therapy aimed at preventing further lipid peroxidation, such as the Zeman regimen, did not slow progression of the disease. Therefore, Santavuori and Westermarck [Santavuori and Westermarck 1984] introduced treatment with a combination of selenium and vitamin E and reported favorable results with few side effects. We present information on the rationale for the use of selenium, recommendations on the daily intake, and reported side effects. However, our limited experience with selenium in this disorder does not permit conclusions. Additionally, careful studies are indicated before this treatment is dispensed routinely.

Child↗
PubMed1988

The predictability of the small-for-gestational-age infant by real-time ultrasound-derived measurements combined with pulsed Doppler umbilical artery velocimetry.

During a 15-month period 373 level II ultrasound examinations were performed in 256 high-risk patients. In addition, pulsed Doppler spectral recordings of blood flow in the fetal umbilical arteries were made. A systolic/diastolic ratio was then calculated for each fetus. Real-time ultrasound-derived estimated fetal weight with the use of biparietal diameter and abdominal circumference was also calculated. The estimated fetal weights were categorized by placing them in a percentile for gestational age according to published nomograms. Complete birth data and outcomes were obtained in all patients. Both the systolic/diastolic ratio and ultrasound-estimated fetal weight grouped by percentile ranking for gestational age were highly predictive (p = 0.001) of babies who were subsequently born small for gestational age. Seventy-nine percent of the infants small for gestational age had umbilical artery systolic/diastolic ratios greater than or equal to 4, whereas only 21% had normal systolic/diastolic ratios. Forty-three percent of the infants who were small for gestational age had ultrasound-estimated fetal weights less than or equal to 10th percentile for the gestational age at which it was measured. Umbilical artery systolic/diastolic ratios, which reflect an increase in peripheral resistance in the placental circulation, showed a highly predictive and discriminatory index for the evaluation of the fetus suspected of having growth retardation.

Birth Weight↗
PubMed1988

Coagulation changes during packed red cell replacement of major blood loss.

A greater proportion of blood replacement needs are being met by packed red cell concentrates rather than whole blood in situations of major blood loss. Twelve patients, who required major blood replacement during elective surgery, were studied to determine the changes in coagulation when packed red cells were used to replace major blood loss. In addition, the coagulation abnormalities present at the time an observer noted excessive bleeding were determined. Prior to blood product replacement and after the estimated loss of each 0.3 blood volume, coagulation tests were obtained including prothrombin time (PT), partial thromboplastin time (aPTT), platelet count, thrombin time (TT), fibrinogen levels, and assays of coagulation Factors V, VIII, and IX. Coagulation tests were repeated when clinical hemostasis was judged inadequate by the anesthesiologist and attending surgeon. Significant decreases in platelet count, fibrinogen levels, and Factor V, VIII, and IX levels occurred as increasing blood volumes were replaced. Increases in PT and aPTT above control occurred in nine of the 12 patients prior to replacement of 1 blood volume; none of the nine patients had increased clinical bleeding. In four of seven patients who had blood replacement of greater than 1 blood volume, increased clinical bleeding was noted by the observer. Platelet counts were less than 100,000/mm3 in each of these four patients, and a platelet concentrate obtained by pheresis of a single donor was administered. In two of the four patients platelet counts increased, but clinical bleeding did not resolve.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Coagulation↗
PubMed1987

Studies of the in vitro effect of methylmercury chloride on rat brain neurotransmitter enzymes.

The in vitro effect of methylmercury (MM) on the enzymatic activities of brain cell specific marker enzymes, choline acetyltransferase (CAT), glutamic acid decarboxylase (GAD), 2',3'-cyclic nucleotide phosphohydrolase (CNP), glutamine synthetase (GS) and enolase was examined. The results demonstrate that at 100 microM MM, GS activity was not affected whereas a small decrease in the activity of both GAD (20%) and enolase (10%) was observed. CNP and CAT activity appeared to be more sensitive toward MM with 100 microM MM producing inhibition of 50% and 30%, respectively. The addition of sulfhydryl protecting reagents such as DTT or sodium thioglycolate can restore the enzyme activities to normal control levels despite prior exposure of the enzymes to MM.

Animals↗
PubMed1987

[Calculation of intracardiac shunt using Doppler echocardiography].

The purpose of this study was to assess the accuracy of a quantitative two-dimensional Doppler echocardiographic method for estimation of intracardiac shunts. The ratio of pulmonary to systemic flow (Qp/Qs) was evaluated by duplex Doppler echocardiography in 20 patients with various intracardiac shunts. Right and left ventricular stroke volumes (RSV, LSV) were determined from the recordings of ejection blood flow velocity and diameter at the level of the pulmonary and aortic orifices in each ventricular outflow tract. The ratio RSV/LSV, determined by duplex Doppler echocardiography, was compared with Qp/Qs by oxymetry. The Doppler echocardiograms were of sufficient quality for shunt calculation in 15/20 patients (75%). The RSV/LSV for ten normal subjects was 0.99 +/- 0.05 (mean +/- SD), whereas the RSV/LSV for 15 patients with intracardiac shunts, 2.6 +/- 0.5, was significantly higher than that for normal subjects (p less than 0.01). In 12/15 patients, the Doppler study estimated the severity of intracardiac shunting correctly. The presence of complex anatomic situations, a wide pulmonary artery or significant semilunar regurgitation seem to have a negative impact on the Doppler echocardiographic shunt calculation. Our findings indicate that, with a few limitations, the Doppler index RSV/LSV is clinically useful in the estimation of the magnitude of the shunt flow in patients with intracardiac shunts.

Adolescent↗