Biomedical subjects

D Washington

Publications and source records attributed to D Washington.

4 recordsLinked to original sources

PubMed1992

Thermoregulatory vasoconstriction during propofol/nitrous oxide anesthesia in humans: threshold and oxyhemoglobin saturation.

To determine the thermoregulatory effects of propofol and nitrous oxide, we measured the threshold for peripheral vasoconstriction in seven volunteers over a total of 13 study days. We also evaluated the effect of vasoconstriction on oxyhemoglobin saturation (SpO2). Anesthesia was induced with an intravenous bolus dose of propofol (2 mg/kg), followed by an infusion of 180 micrograms.kg-1 x min-1 for 15 min, and maintained with 60% nitrous oxide and propofol (80-160 micrograms.kg-1 x min-1). Central and skin surface temperatures and SpO2 (using two different pulse oximeters) were measured continuously; plasma propofol concentrations and arterial PO2 were measured at 15-min intervals. Volunteers were cooled with a circulating water blanket until definitive peripheral vasoconstriction was detected. The tympanic membrane temperature triggering vasoconstriction was considered the thermoregulatory threshold. Vasoconstriction developed on seven study days during propofol/nitrous oxide anesthesia at a central temperature of 33.3 +/- 1.0 degrees C (mean +/- SD) and plasma propofol concentration of 3.9 +/- 1.1 micrograms/mL. The thresholds during anesthesia were significantly lower than those during the control period (36.7 +/- 0.3 degrees C), but the correlation between plasma propofol concentrations and vasoconstriction thresholds was poor. On the remaining six study days, vasoconstriction did not develop despite central temperatures ranging from 32.1 to 32.7 degrees C. Corresponding propofol concentrations were 4.1-10.9 micrograms/mL. These data suggest that anesthesia with propofol, in typical clinical concentrations, and 60% nitrous oxide substantially inhibits thermoregulatory vasoconstriction. Vasoconstriction increased SpO2 by approximately 2% without a significant concomitant change in PO2. The observed increase in SpO2 probably reflects decreased transmission of arterial pulsations to venous blood in the finger.

Adult↗

PubMed1988

Emergency computerized tomography of tracheoesophageal fistula in lung adenocarcinoma.

Malignant tracheoesophageal fistula occurs infrequently in patients with irradiated esophageal and lung cancer, uncommonly in patients with untreated mediastinal malignancies, infection, or trauma, and rarely in primary adenocarcinoma of the lung. The natural progression of this entity leads to rapid deterioration and death from overwhelming pulmonary infection.Definitive treatment depends on the demonstration and localization of the fistula. Computerized tomography (CT) chest scanning with dilute oral contrast is the ideal means of identification of the fistula. CT scanning without contrast may outline sufficiently the pathology to avoid the usage and side effects of contrast media in the lungs.A review of one case of tracheoesophageal fistula due to pulmonary adenocarcinoma is presented where emergency CT scanning without contrast resulted in rapid and accurate diagnosis, leading to prompt and appropriate management.

Adenocarcinoma↗

PubMed1987

Occult mucous airway obstruction in diabetic ketoacidosis.

Four patients with diabetes mellitus and no underlying clinical pulmonary disease were found to have extensive unilateral mucous occlusion of a major central bronchus. None of the patients had significant auscultatory findings suggestive of pulmonary secretions, and chest roentgenographic films were normal. Arterial blood gas evaluation failed to reveal the usual hypocapnia during ketoacidosis, thus prompting bronchoscopic examination or deep airway suctioning. These interventions disclosed and resolved the mucous obstruction of the compromised bronchus. Antibiotic therapy, based upon bronchial secretion Gram stain and culture, was successfully instituted in all patients. Lethargy and autonomic neuropathy are proposed as contributing factors responsible for occult mucous plugging in diabetic patients in ketoacidosis. The absence of hypocapnia in this setting may be the only clue to silent mucous plugging of airways.

Adult↗

PubMed1975

Bacteroidosis.

Bacteroides infection frequently complicates surgery, instrumentation, or trauma to the alimentary, upper respiratory, and female genitourinary tracts. Bacteroides sp, alone or with other organisms, also may cause infections in the ear, nose, and throat, and other tissues where defeneses are lowered. Foul-smelling pus, sinus drainage, material from an abscess or infected traumatic wound, or a blood culture made because of a suspected anaerobic complication should be subjected to anaerobic study in the laboratory. Treatment of clinical bacteroidosis consists of specific antibiotics, surgery, oxygen under pressure, and appropriate local dressings. Treatment is often more effective if at least two antibiotics are given concurrently, and antibiotic sensitivity tests are recommended to select the best combination.

Ampicillin↗