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Biomedical subjects

D L Steed

Publications and source records attributed to D L Steed.

At least 91 records · Page 5Linked to original sources
PubMed1981

Tympanometric changes after total maxillary osteotomy.

With the frequency of orthognathic surgery increasing each year, more is being learned about this surgical art. Although techniques are improving, more acute and chronic complications are being reported after orthognathic surgery. In our institution, it has been noticed that approximately 25% to 30% of our patients experience unilateral or bilateral otalgia after total (Le Fort I) maxillary osteotomy. Recently, two patients with maxillary osteotomies. In both patients acute otitis media developed postoperatively and myringotomies for relief of symptoms were required. This paper reports changes observed in preoperative and postoperative tympanograms of patients who undergo total maxillary osteotomy and offers a possible explanation for these middle ear changes, which are accompanied by otalgia.

Acoustic Impedance Tests↗
PubMed1981

Correction of hemifacial microsomia.

Hemifacial microsomia is a combination of malformations of the first and second branchial arch derivatives. Reconstruction of three adult cases of hemifacial microsomia with varying degrees of deformity was presented.

Adolescent↗
PubMed1981

Reducing postischemic damage by temporary modification of reperfusate calcium, potassium, pH, and osmolarity.

This study was designed to determine if ischemic damage could be reduced by modifying blood composition upon reperfusion. After control data had been obtained in seven dogs on prolonged cardiopulmonary bypass, 71 dogs underwent 1 hour of ischemic arrest with topical hypothermia (left ventricular temperature 16 degrees C). We measured left ventricular performance (isovolumetric function curves), compliance (intraventricular balloon), blood flow (microspheres), metabolism (oxygen consumption), and water content (wet/dry weights) before and 30 minutes after ischemia. The initial reperfusate was 500 cc of oxygenated blood given over a period of 5 minutes. Without temporary reperfusate modification, postischemic left ventricular performance was depressed 40% +/- 3%, compliance fell 50% +/- 12%, water content rose 2.5% +/- 0.1%, and left ventricular blood flow and oxygen uptake increased only minimally when cardiac work was increased (function curve). These deleterious changes were reduced significantly, but not prevented, by the following isolated reperfusate modifications: (1) lowering amount of ionic calcium available for cell entry, (2) raising pH to 7.8 to counteract acidosis, (3) raising potassium level to maintain arrest and reduce metabolic demands, and (4) increasing osmolarity (mannitol, 360 mOsm) to counteract edema. In contrast, by combining these modifications to achieve a hypocalcemic, hyperkalemic, alkalotic, and hyperosmolar blood perfusate, it was possible to attain 104% +/- 1% recovery of myocardial performance, 80% +/- 1% restoration of compliance, 60% less postischemic edema, and near-normal augmentation of left ventricular flow and oxygen uptake to meet increasing needs.

Animals↗
PubMed1980

The keratinizing and calcifying odontogenic cyst (Gorlin cyst).

A 61-year-old white woman had a radiolucent lesion in the anterior portion of the mandible which was diagnosed as a keratinizing and calcifying odontogenic cyst. As it has a radiographic appearance similar to other pathologic processes, it should be considered in the differential diagnosis when a radiolucent-radiopaque lesion is encountered.

Diagnosis, Differential↗
PubMed1979

Iatrogenic myocardial edema with potassium cardioplegia.

Postischemic myocardial edema depresses left ventricular function and coronary perfusion. Pharmacologic cardioplegia is being used increasingly to enhance myocardial protection during cardiac operations. In the present study we varied the colloid osmotic and osmotic pressures and the infusion pressures of four cardioplegic solutions to determine their respective roles in producing or preventing myocardial edema in a nonischemic setting. We found that myocardial edema during potassium cardioplegia (1) is independent of infusion pressures, (2) is caused by isosmotic crystalloid solutions, (3) is worsened by hyposmolar crystalloid solutions, (4) is avoided by the addition of colloid, and (5) is avoided if the solution is made hyperosmotic with the addition of mannitol.

Animals↗
PubMed1978

Osteoma cutis: cutaneous ossification with oral manifestations.

Subcutaneous and mucosal calcifications are rare lesions which present problems in diagnosis. A large bony mass is presented, with dermal and mucosal findings. The literature is reviewed on this non-neoplastic bony lesion and differential diagnosis is discussed.

Adolescent↗
PubMed1978

Effects of pulsatile assistance and nonpulsatile flow on subendocardial perfusion during cardiopulmonary bypass.

We compared the effects of pulsatile and nonpulsatile perfusion in 12 dogs on extracorporeal circulation. In beating empty and fibrillating hearts at 37 degrees and 28 degrees C, coronary blood flow was measured by flowmeter and microspheres at diastolic pressures ranging between 50 and 130 mm Hg. At fixed systemic flow rates (range, 600 to 2,400 ml/min), pulsatile perfusion produced a transient (3 to 4 second) augmentation of diastolic pressure and then resulted in the following: (1) decreased peripheral vascular resistance (p less than 0.05); (2) unchanged peak diastolic pressure (compared with nonpulsatile perfusion); (3) decreased mean aortic pressure (6 to 37%) (p less than 0.05); (4) decreased coronary blood flow (10 to 45%) (p less than 0.05); and (5) decreased subendocardial blood flow (from 512 to 438 ml/100 gm/min) (p less than 0.05). Pulsatile perfusion in beating hearts (37 degrees or 28 degrees C) did not reduce subendocardial vascular resistance, but did improve subendocardial perfusion by 27% and 36% in fibrillating hearts at 37 degrees and 28 degrees C, respectively. We conclude that with the exception of ventricular fibrillation, pulsatile assistance offers no advantage over nonpulsatile perfusion and has the potential disadvantage of requiring higher pump flow rates to achieve any desired level of coronary and subendocardial flow.

Animals↗
PubMed1978

Advantages of intermittent blood cardioplegia over intermittent ischemia during prolonged hypothermic aortic clamping.

Ten dogs underwent 2 hours of hypothermic (22 degrees C) aortic clamping. Arrest was produced by ischemia in five dogs, with 150 ml of 22 degrees C unmodified blood reperfused every 20 minutes. Five others underwent cardioplegic arrest (500 cc pH 7.8 blood containing 30 mEq/L KCl, 0.6 mEq/L Ca++) with 150 ml of blood cardioplegia solution replenished each 20 minutes. Seven additional dogs underwent 4 hours of continuous coronary perfusion without ischemia. Continuous coronary perfusion did not change myocardial ATP or water content, but reduced left ventricular contractility (maximum positive dP/dt, peak systolic pressure) 16% (P < 0.05) and decreased left ventricular compliance moderately (50%). Hypothermic ischemic arrest reduced myocardial ATP 39% (P < 0.05), raised myocardial water 3.2% (P < 0.05), reduced compliance 83% (P < 0.05), and depressed left ventricular performance 64% (P < 0.05), despite intermittent reinfusion of unmodified blood each 20 minutes. In contrast, blood cardioplegia reduced postischemic left ventricular compliance only slightly 17%, P < 0.05) and resulted in normal postischemic ATP, water, and contractility.

Animals↗
PubMed1978

Hyperbaric oxygen in the adjunctive treatment of chronic osteomyelitis of the mandible: report of case.

A case of chronic osteomyelitis has been presented to show the effectiveness of hyperbaric oxygen in treatment of this disease. Surgical intervention is needed, as are adequate cultures, even though the cultures may be difficult to obtain and identify. Because the antibiotic therapy may need to be changed during the course of the disease, the selection of antibiotics should be dictated by positive cultures as well as the clinical course. Antibiotic therapy is needed for four to six weeks after abatement of symptoms.

Child↗