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Dive into the research topics where Gerald R. Onstad is active.

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Featured researches published by Gerald R. Onstad.


Annals of Surgery | 1983

Aminopyrine breath test predicts surgical risk for patients with liver disease.

Robert A. Gill; Michael W. Goodman; Gene R. Golfus; Gerald R. Onstad; Melvin P. Bubrick

To determine whether the [14C] aminopyrine breath test (ABT) predicts surgical risk in patients with liver disease, it was obtained prior to various surgeries in 38 patients with known or suspected liver disease. A modified Childs classification was also determined. Six of the seven operative deaths (three Childs A, two B, two C) had ABTs < 2.3%, while 30 of 31 survivors (24 Childs A, seven B) had ABTs > 2.3% (p < 0.000018). Seven of the 16 patients with normal ABTs had biopsy-proven cirrhosis and had postoperative courses indistinguishable from the remainder of the group. We conclude that surgery in patients with ABTs < 2.3% is associated with extremely high mortality. In addition, cirrhotics with normal ABTs tolerate elective surgery well.


Gastrointestinal Endoscopy | 1993

The non-bleeding visible vessel versus the sentinel clot: natural history and risk of rebleeding

Martin L. Freeman; Oliver W. Cass; Craig J. Peine; Gerald R. Onstad

Non-bleeding visible vessel and sentinel clot are terms used interchangeably to describe protuberances in the base of ulcers that have recently bled, but a consensus as to their definition or natural history does not exist. In patients with severe ulcer hemorrhage, non-bleeding protuberances were classified as vessels, with or without a small attached clot, or as sentinel clots, according to a schema based on the appearance of the protuberance at endoscopy but not subjected to pathologic correlation. Endoscopic therapy was not performed at the index endoscopic evaluation, and natural evolution was prospectively documented with daily videoendoscopy. Eleven (46%) of 24 patients with non-bleeding protuberances had rebleeding. Independent classification by three authors concurred in 18 (75%) of 24 lesions. Ten (91%) of 11 vessels with or without attached clot rebled versus 0 (0%) of 7 sentinel clots and 1 (17%) of 6 lesions without unanimous classification (p < 0.01, vessels versus other groups). Rebleeding occurred in 5 (71%) of 7 nonpigmented (pale or white), 6 (38%) of 16 red or purple, and 0 (0%) of 1 black protuberances. In general, vessels persisted until rebleeding, whereas sentinel clots disappeared within 1 to 3 days. We conclude that nonbleeding protuberances in ulcer bases can be separated into vessels, which have a high risk of rebleeding, and sentinel clots, which have a low risk of rebleeding.


Annals of Internal Medicine | 1982

Hepatic Veno-Occlusive Disease Caused by 6-Thioguanine

Robert A. Gill; Gerald R. Onstad; Joseph M. Cardamone; Daniel C. Maneval; Hatton W. Sumner

Clinically reversible veno-occlusive disease of the liver developed in a 23-year-old man with acute lymphocytic leukemia after 10 months of maintenance therapy with 6-thioguanine. Serial liver biopsies showed the development and resolution of intense sinusoidal engorgement. Although this disease was clinically reversible, some subintimal fibrosis about the terminal hepatic veins persisted. This case presented a unique opportunity to observe the histologic features of clinically reversible hepatic veno-occlusive disease over time, and may be the first case of veno-occlusive related solely to 6-thioguanine.


Gastrointestinal Endoscopy | 1976

Lift and cut biopsy technique for submucosal sampling

T.R. Martin; Gerald R. Onstad; S.E. Silvis; J.A. Vennes

The lift-and-cul biopsy technique is proposed for the evaluation of selected lesions of the gastric submucosa. The safety and success of the procedure is due to the use of a biopsy forceps to raise a pedicle of tissue before snaring and electrocoagulation. When the specimen is properly obtained and oriented for sectioning, the procedure consistently yields submucosa. It may offer an alternative to exploratory lapdrotomy for the purpose of adequate biopsy.


Diseases of The Colon & Rectum | 1980

The relationship of hemorrhoids to portal hypertension

Donald M. Jacobs; Melvin P. Bubrick; Gerald R. Onstad; Claude R. Hitchcock

Records of 188 patients with documented portal hypertension were reviewed to determine the incidence of hemorrhoids as well as bleeding complications associated with this condition. The incidence of hemorrhoids among these patients was not increased compared to the normal population. Six of the patients with portal hypertension did, however, bleed massively from hemorrhoids. Elevated portal venous pressure is an important factor in those patients having severe hemorrhoidal bleeding. The presence of coagulation defects may also be of considerable importance.


Gastrointestinal Endoscopy | 1995

Fluoroscopy is not necessary for Maloney dilation of chronic esophageal strictures.

Samuel B. Ho; Oliver W. Cass; Ralph J. Katsman; Ellen M. Lipschultz; Rita J. Metzger; Gerald R. Onstad; Stephen E. Silvis

The use of fluoroscopic guidance for Maloney dilation is controversial. In order to determine if fluoroscopic analysis would enhance the success of dilation and increase recognition of adverse events, we prospectively studied 125 Maloney dilations in 80 patients (mean age, 69.3 years) with mild esophageal strictures. Most strictures (89%) resulted from acid-peptic disease. Operators included two staff physicians (5 and 25 years of experience) and one trainee (1 year of experience). Dilations were performed with the patient seated upright and the operator noting the presence and amount of resistance (dilator size, 36F to 60F; median, 50F). The fluoroscopic monitor was not visible to the operator, and the results were recorded by an observer who did not communicate with the operator. Operator assessment of Maloney dilation was correct in 122 of 125 procedures. Two failures were interpreted as no passage by the operator when passage had occurred as confirmed by fluoroscopy. One failure was interpreted as passage when no passage had occurred as indicated by fluoroscopy. Adverse events included 1 episode of tracheal intubation and failure to recognize the dilator tip curling in the esophagus as observed by fluoroscopy in 6 of 125 (4.8%) procedures. Operator assessment of resistance was more often associated with curling of the dilator on the greater curve of the stomach than with an esophageal stricture. Greater operator experience tended to correlate with increased success and correct interpretation of dilation. Maloney dilations performed with patients at 30 degrees rather than upright at 90 degrees were associated with a marked increase in unsuccessful dilator passage and curling of dilator tip.(ABSTRACT TRUNCATED AT 250 WORDS)


Clinical Pharmacology & Therapeutics | 1982

Cimetidine dynamics after single intravenous doses.

Sal Pancorbo; Melvin P. Bubrick; Thomas W F Chin; Kenneth W Miller; Gerald R. Onstad

Cimetidine dynamics were studied in nine multiple‐trauma patients. Mean elimination half‐life was 2.27 hr, mean volume of the central compartment was 0.29 l/kg, mean volume at steady state averaged 0.90 l/kg, and mean total body clearance was 9.02 ml/min/kg. After intravenous cimetidine, drug concentrated in gastric fluid reached a peak concentration in 3 hr. Gastric plasma cimetidine ratios after equilibration ranged between 3.0 and 4.3. There was a correlation between cimetidine gastric juice concentration and gastric pH (r = 0.50), but no correlation was found between plasma cimetidine concentration and pH (r = 0.13)


Journal of General Internal Medicine | 1995

Omeprazole use at an urban county teaching hospital

David J. Brandhagen; Alfred M. Pheley; Gerald R. Onstad; Martin L. Freeman; Nicole Lurie

To determine the appropriateness of use of omeprazole, all outpatient prescriptions over one year from a single county hospital pharmacy were analyzed. Appropriateness of omeprazole use was assessed by literature review and expert opinion. Two hundred twenty-one prescriptions were evaluated; 112 (56%) were inappropriate. Women received more inappropriate prescriptions (61% vs 44%, p=0.01) and received endoscopy less frequently (52% vs 71%, p<0.02) than did men. When age, gender, and prescribing clinic were examined as predictors of inappropriate use, only gender was significant (OR=2.01, 95% CI=1.52–2.66). This study, from a single institution, showed a high rate of inappropriate omeprazole use.


Clinical Pharmacology & Therapeutics | 1984

Cimetidine dynamics after repeated intravenous injection.

Salvador Pancorbo; Melvin P. Bubrick; Thomas W F Chin; Kenneth W Miller; Gerald R. Onstad

Cimetidine dynamics were studied in six multiple‐trauma patients receiving 300 to 600 mg every 6 hr for prevention of stress ulceration. Patients received cimetidine intravenously for a mean duration of 7.8 days. There was a positive correlation between cimetidine serum concentration and gastric pH; the correlation between intragastric cimetidine concentration and gastric pH was stronger. The association between therapeutic efficacy (pH > 4) and serum concentration over 1 mcg/ml was significant. The association with gastric cimetidine concentration above 2 mcg/ml was significant.


Annals of Internal Medicine | 1979

Misleading second-stage Schilling tests due to inactive intrinsic factor concentrate.

Bruce E. Jacobson; Gerald R. Onstad

Excerpt The second-stage Schilling test (performed with intrinsic factor from hogs) is used to distinguish pernicious anemia from intestinal disorders such as Crohns disease. We reviewed our exper...

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Melvin P. Bubrick

Hennepin County Medical Center

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Oliver W. Cass

Hennepin County Medical Center

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Thomas W F Chin

Hennepin County Medical Center

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Craig J. Peine

Hennepin County Medical Center

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Donald M. Jacobs

Hennepin County Medical Center

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Kenneth W Miller

Hennepin County Medical Center

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Sal Pancorbo

Hennepin County Medical Center

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Alfred M. Pheley

Hennepin County Medical Center

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