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Biomedical subjects

D W Olson

Publications and source records attributed to D W Olson.

28 records · Page 2Linked to original sources
PubMed1989

MAST-associated compartment syndrome (MACS): a review.

Compartment syndromes occur following lower extremity injuries and have been associated with the use of pneumatic or "medical" antishock trousers (MAST). Review of 12 previously reported cases and 15 new cases suggests that lower extremity trauma and systemic hypotension are cofactors responsible for the development of compartment syndrome but MAST use also contributes to the process by prolonging muscle ischemia. Complications of lower limb compartment hypertension may be averted by early recognition and fasciotomy. Associated amputations and mortality are directly related to the severity of injury, or indirectly to delay in diagnosis and treatment of the compartment syndrome and its complications.

Abdominal Injuries↗
PubMed1987

Limitations of prehospital predictors of acute myocardial infarction and unstable angina.

Studies have attempted to define predictive indicators of diagnosis and/or prognosis for acute myocardial infarction (AMI) in the emergency department and to identify the need for hospital admission in patients with chest pain. Because prehospital predictors have not been defined, dispatchers, paramedics, and base station physicians continue to triage based on patient history. We reviewed 401 patients presenting in one year to an urban paramedic system with chest pain, normal vital signs, and stable rhythms to identify predictors of AMI and unstable angina. Thirty-one percent (123) had a diagnosis of AMI, 26% (105) unstable angina, and 43% (173) "other" diagnoses. Two-hundred seventy-eight patients required nitroglycerin administration, 182 required IV morphine, 14 developed arrhythmias requiring lidocaine, and two suffered cardiac arrest in the field. Nine other patients had a cardiac arrest after arrival in the ED. When comparing AMI and unstable angina patients to the "others," 64% (132) versus 36% (74) had radiation of pain (P less than .003), 72% (95) versus 28% (37) had diaphoresis (P less than .0001). Neither difficulty breathing, nausea/vomiting, vital signs, initial rhythm, nor past history of myocardial infarction were helpful in discriminating AMI and unstable angina from others. Comparing AMI alone versus others, the presence of ST segment elevation on lead II was present in 15% (18) AMIs, 3% (3) unstable angina, and 8% (14) others (P = .005). Diaphoresis also was a predictor of diagnosis with 51% (63) of the AMIs and 25% (69) of others exhibiting this sign (P less than .001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

A randomized comparison study of bretylium tosylate and lidocaine in resuscitation of patients from out-of-hospital ventricular fibrillation in a paramedic system.

A prospective, randomized study using either bretylium tosylate (BT) or lidocaine (L) as the first-line antiarrhythmic for patients in refractory ventricular fibrillation was conducted using the Milwaukee County Paramedic System. If the patient did not respond to the initial American Heart Association protocol, BT (10 to 30 mg/kg total) or L (2 to 3 mg/kg total) was given randomly as the first antiarrhythmic. If the patient failed to convert, the alternate antiarrhythmic was given. In the L group, 81% (39/48) of the patients obtained an organized electrical rhythm and 56% (27/48) converted to a rhythm with a pulse. The resuscitation rate (admission to an emergency department with pulse) was 23% (11/48), and the save rate was 10.4% (5/48). In the BT group, 74% (32/43) obtained an organized electrical rhythm, 35% (15/43) were converted, 23% (10/43) were resuscitated, and 5% (2/43) were saved. The only significant difference in outcome was that L converted patients better than did BT (P less than .05). Of the 24 patients known to be on digitalis preparations prior to arrest, 41% (5/12) in the L group were resuscitated and 16% (2/12) were resuscitated in the BT group. Data were analyzed for witnessed arrest outcome and for patients given multiple antiarrhythmics.

Aged↗
PubMed1984

Vascular injury related to lumbar disk surgery.

This report summarizes the Walter Reed Army Medical Center experience with six patients operated on from 1949 through 1982 for vascular injury related to lumbar disk surgery. All had common iliac artery injuries generated by L4-5 disk operations. Four patients had isolated arterial injuries and two had combined arteriovenous injuries. Three underwent vascular repair acutely, two with shock and one with a false aneurysm. Delay in diagnosis occurred in two patients who presented 6 weeks and 3 years postinjury with minimally symptomatic arteriovenous fistulae. A sixth patient had a known arterial injury and was operated on after a 1-month delay. All patients survived. Two patients had had repeated back operations, suggesting that this may be a risk factor for perforation of the anterior spinal ligament by an operative rongeur.

Adult↗
PubMed1983

Performance of dwarf and normal laying hens as influenced by protein level and cage density.

The performance of dwarf and normal White Leghorn laying hens with similar genotypes other than for the dwarf gene (dw) was observed over thirteen 28-day periods in a factorial arrangement involving four protein levels (20.0, 18.1, 16.4 or 14.3% protein plus supplemental methionine) and two densities (two or three birds per standard 10 X 16 in cage). The normal birds had significantly higher overall hen-day egg production, egg weight, and body weight, but the dwarf birds excelled for feed efficiency and adult viability. Significant genotype X ration interactions were observed for egg lay, egg weight, body weight, and feed efficiency, primarily due to the relatively poor performance of the dwarf birds on the 14% protein. A significant genotype X density interaction resulted for feed efficiency, due to a higher efficiency in 3-bird than in 2-bird cages for dwarf birds, while the reverse was true for normal birds. These results suggest that the potential of the dwarf gene for increasing the efficiency of commercial egg layers can be enhanced by further study as to optimal nutrition and management regimens.

Animals↗
PubMed1983

Dilation of knitted Dacron aortic prostheses and anastomotic false aneurysms: etiologic considerations.

Five patients with knitted Dacron aortic bifurcation prostheses developed prosthetic dilation and anastomotic false aneurysms. The interval between placement of prostheses and secondary presentation ranged from 4 to 10 years. Three patients presented with femoral false aneurysms (one ruptured) and two presented with aortic false aneurysms (one ruptured). In all cases, anastomotic sutures remained intact on the prosthesis and there was no evidence of infection. The mean (+/- SEM) increase in diameter of prostheses was 85.7 +/- 19.1% (range 76% to 137%). Dilated prostheses were removed in four cases and were tested for tensile strength and studied with scanning electron microscopy. These were compared to normal, nondilated knitted Dacron prosthetic fabric from the same manufacturer. There was no loss of breaking strength in dilated prostheses. Furthermore, on examination with scanning electron microscopy, there was no evidence of degeneration or fracturing of individual Dacron filaments. However, dilated prostheses were found to have a greatly expanded knit. The distance between loops was significantly increased and the number of fibers per 1000 microns was significantly less in comparison to normal knitted Dacron fabric. These studies confirm an association between prosthetic dilation and false aneurysm formation. Further, they suggest that the cause of prosthetic dilation is loss of compactness of the knit not associated with intrinsic Dacron fiber deterioration. A fabrication defect is most likely responsible.

Aged↗
PubMed1983

Percutaneous transluminal balloon angioplasty of the iliac artery for contralateral ischemia.

The cases of three patients with lower extremity ischemia from ipsilateral iliac artery occlusion and contralateral iliac artery stenosis are presented. Planned treatment was percutaneous transluminal angioplasty (PTA) of the contralateral iliac artery, rendering it an adequate donor vessel for subsequent femorofemoral bypass. Because of adequate collateral vessels across the pelvis, cross-femoral bypass was unnecessary following PTA. Current technology allows simultaneous intraoperative PTA and femorofemoral bypass. We do not recommend this on the basis of our experience.

Aged↗
PubMed1983

Etiologic factors for recurrent carotid artery stenosis.

Since 1966, 29 patients with recurrent carotid artery stenosis have been encountered. The mean (+/- SEM) internal between initial carotid endarterectomy and secondary presentation was 67.5 +/- 9.2 months (range 6 to 180 months). There was a disproportionate number of women with recurrent stenosis. The mean age at initial endarterectomy in patients with recurrent stenosis, 54.6 +/- 1.4 years, was significantly less (P less than 0.001) than that of all patients who had endarterectomy. To define the etiologic factors for recurrence, 21 of these patients were matched with case-control patients of the same age and sex who had undergone endarterectomy the same year but did not develop recognized recurrent stenosis. There was no significant difference in the incidence of hypertension, diabetes mellitus, coronary artery disease, bilateral carotid disease, other vascular operations, or family history for atherosclerosis in patients with recurrent stenosis compared to control patients. The indications for primary endarterectomy, angiographic distribution of disease, and operative details were similar in both groups. There was no difference in the incidence of regular, therapeutic aspirin ingestion following initial endarterectomy (52.5% in both groups). There was a striking difference in smoking habits. Ninety-five percent of patients with recurrent stenosis continued to smoke following initial endarterectomy, compared to 23.8% of control patients (P less than 0.001). Lipid fractionation studies were performed in both groups, and there were no significant differences in levels of cholesterol, triglycerides, high-density lipoprotein (HDL)-cholesterol, and total cholesterol/HDL-cholesterol ratio. Dose-response platelet aggregometry detected no differences between groups in the sensitivity of platelets to adenosine diphosphate (ADP), collagen, and epinephrine. Reoperation in patients with recurrent stenosis was associated with minimal morbidity, no deaths, and generally excellent results.

Anesthesia↗
PubMedDate not supplied

50% dextrose: antidote or toxin?

The empiric administration of 50% dextrose to all patients presenting to the ED with altered mental status is a standard of care predicated on the assumption that glucose administration is harmless to nonhypoglycemic patients. Considerable evidence now disputes this assumption. Glucose administration before complete cerebral ischemia in experimental animals worsens neurologic and histologic outcome. Administration of glucose during severe incomplete ischemia has a similar detrimental effect. The translation of these experimental findings into clinical practice has been slow, perhaps hindered by the frequent use of rodent models and large bolus doses of glucose. However, evidence is now provided by primate and human studies and by experimental designs using clinically relevant doses of glucose. These clinical and experimental findings in conjunction with the wide availability of a rapid bedside screen for hypoglycemia provide the rationale for an alteration in the standard of care. The empiric administration of glucose should be avoided in patients at risk of cerebral ischemia, such as those with acute stroke, impending cardiac arrest, or severe hypotension or receiving CPR. A bedside fingerstick blood glucose estimation should be performed immediately on all patients presenting with altered mental status. The administration of 50% dextrose should be reserved for those patients in whom hypoglycemia is demonstrated; this practice will uphold Hippocrates' most basic principle of clinical medicine, "The physician must...do no harm."

Animals↗