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Biomedical subjects

B D Wright

Publications and source records attributed to B D Wright.

63 records · Page 4Linked to original sources
PubMedDate not supplied

A hydroponic system for microgravity plant experiments.

The construction of a permanently manned space station will provide the opportunity to grow plants for weeks or months in orbit for experiments or food production. With this opportunity comes the need for a method to provide plants with a continuous supply of water and nutrients in microgravity. The Capillary Effect Root Environment System (CERES) uses capillary forces to maintain control of circulating plant nutrient solution in the weightless environment of an orbiting spacecraft. The nutrient solution is maintained at a pressure slightly less than the ambient air pressure while it flows on one side of a porous membrane. The root, on the other side of the membrane, is surrounded by a thin film of nutrient solution where it contacts the moist surface of the membrane. The root is provided with water, nutrients and air simultaneously. Air bubbles in the nutrient solution are removed using a hydrophobic/hydrophilic membrane system. A model scaled to the size necessary for flight hardware to test CERES in the space shuttle was constructed.

Capillary Action↗
PubMedDate not supplied

Morphine requirements using patient-controlled analgesia: influence of diurnal variation and morbid obesity.

The influence of diurnal variation and morbid obesity on the morphine requirements of patients using patient-controlled analgesia (PCA) was studied. Forty-six patients undergoing either elective (Group I) or gastric bypass (Group II) surgery composed the study group. Patients were allowed to use the PCA machine for 36 to 72 hours postoperatively to deliver 0.6 mg/sq m doses of morphine sulfate intravenously. Counters on the device indicating the number of doses received were monitored every two hours along with vital signs and a pain and sedation rating. Dosing rates were studied with regard to the time of day. Morbid obesity had no significant effect on dosing rate requirements. Analyses revealed a significant diurnal rhythm in morphine dosing rate requirements despite a 27-fold interpatient variability. Peak analgesic use was at 0900, and the nadir was at 0300. Patient pain rankings did not indicate any changes in pain status, demonstrating PCA's use of analgesia as an endpoint for dosing. Sedation status showed a higher degree of sedation at night when compared with the daytime values, documenting that sedation was not drug-induced. There is a circadian variation in narcotic analgesic need in the postoperative patient that is met appropriately by PCA.

Adult↗
PubMedDate not supplied

Pulmonary complications in the morbidly obese following jejunoileal bypass surgery under narcotic anesthesia.

The postoperative pulmonary complications detected by chest roentgenogram were correlated with the age, body weight, excess weight/ideal body weight, results of spirometry, arterial blood gas values and duration of anesthesia in 99 obese patients (mean weight 146.8 kg) who underwent jejunoileal bypass surgery under narcotic anesthesia. The overall postoperative pulmonary complication rate was 25.3 per cent. Age, body weight, excess weight/ideal body weight, preoperative vital capacity (VC), VC per cent of the predicted, forced expiratory volume 1 sec. over forced vital capacity (FEV1/FVC) PaO2 per cent of the predicted, PaCO2 and duration of anesthesia were of no value in predicting postoperative pulmonary complications. The presence of associated clinical diseases expected to affect pulmonary function (e.g., chronic bronchitis, congestive heart failure) was the only significant variable in this regard (p less than 0.01). In 85 patients who did not have an associated disease expected to affect pulmonary function, the incidence of pulmonary complication was 20 per cent; the results of spirometry were essentially normal, but the PaO2 was significantly decreased. In 14 patients with an associated disease expected to affect pulmonary function, the incidence of pulmonary complication was 57.1 per cent. The mean VC and mean PaO2 were significantly decreased; the mean age and mean PaCO2 were significantly higher in the group as compared with those in the patients without an associated disease.

Adolescent↗