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Biomedical subjects

D B Weeks

Publications and source records attributed to D B Weeks.

At least 37 records · Page 2Linked to original sources
PubMed1983

Laboratory investigation of six artificial noses for use during endotracheal anesthesia.

The performances of six commercially available heat and moisture exchangers (HMEs) or "artificial noses," were evaluated in the laboratory. Each HME was studied with both a semiclosed anesthesia circuit (SCAC) and a nonrebreathing anesthesia system (NRS). Our results suggest that the Servohumidifier 150 and the Engström Edith are suitable for replacing nasopharyngeal humidification mechanisms bypassed during endotracheal ventilation in all patients because they provided at least 20 mg of water per liter of minute ventilation (mg/L) in an NRS and 28 mg/L in an SCAC during inspiration. While the other four units were suitable for small tidal volumes, they only marginally satisfied minimal suggested humidity levels in the presence of larger tidal volumes.

Anesthesia, Endotracheal↗
PubMed1978

Physiologic saline solution, Normosol R pH 7.4, and Plasmanate as reconstituents of packed human erythrocytes.

The authors compared the effects of three reconstituent solutions (Normosol R pH 7.4, physiologic saline solution, and Plasmanate) on hemolysis and cellular morphology of young (8-10 days' storage) and old (22-26 days' storage) packed human erythrocytes (PE). These variables were tested at 22 and 37 C and at two dilutions )1 part PE:1 part reconstituent and 2 parts PE:1 part reconstituent). Plasmanate produced unacceptably high levels of hemolysis, particularly of older PE, and should not be used as a reconstituent. Normosol R pH 7.4 and physiologic saline solution were compatible with both young and old PE, producing similar changes in hemolysis and erythrocytic morphology, Therefore, Normosol R pH 7.4 may be used as a diluent for PE when rapid and massive infusions are needed.

Blood Proteins↗
PubMed1976

Provision of endogenous and exogenous humidity for the Bain breathing circuit.

The endogenous humidity produced by a partial rebreathing system, the Bain Breathing Circuit, was measured clinically and experimentally. The addition of humidification by interposing a Garthur Vapor Condenser (HME) or a Bennett Cascade heated humidifier into the system was also studied. Without supplemental humidity, the Bain Breathing Circuit probably meets marginal requirements for preservation of ciliary morphology and function during endotracheal anaesthesia. However, additional humidity is needed to prevent alteration in pulmonary mechanics. The HME is a beneficial adjunct to the Bain Breathing Circuit, raising humidity to near acceptable levels, especially if ambient temperatures range from 24 degrees to 26 degrees C. However, the deadspace of the HME is 17 ml, which might limit its use in children. The Bennett Cascade humidifier plus the Bain Breathing Circuit satisfies minimal suggested humidity requirements at ambient reservoir water temperatures of 24 degrees to 26 degrees C. Heating the reservoir water to maximum heat capacity increased humidity but caused marked water condensation along the inner fresh gas tube of the Bain Breathing Circuit.

Adolescent↗