Evaluating diaphragm activity in trauma patients.

The diaphragm is the major respiratory muscle responsible for most of the inspiratory work of breathing. Bedside clinicians often overlook the need to assess the diaphragm or have never focused their attention on understanding the mechanisms behind this muscle. This article updates the trauma nurse on the anatomy and physiology of the diaphragm, reviews current methods for assessing diaphragm activity, and discusses research and diagnostic methods concerning the diaphragm. With heightened awareness of diaphragmatic function, clinicians may be able to improve the respiratory status of the trauma patient by preventing diaphragm fatigue or exhaustion.

Selectivity enhancement of an Escherichia coli bacterial electrode using enzyme and transport inhibitors.

The feasibility of using specific enzyme and transport inhibitors to minimize the glutamine response of a potentiometric microbial sensor is demonstrated. The glutamine response of a bacterial electrode prepared with Escherichia coli as the biocatalyst in conjunction with an ammonia gas-sensing electrode was greatly reduced by treating the electrode with the enzyme inhibitor 6-diazo-5-oxo-L-norleucine (DONL) and the transport inhibitor gamma-L-glutamylhydrazide. Each inhibitor effectively decreased glutamine response to a level sufficiently low to be considered negligible in clinical studies. Although the sensor ultimately recovered from the effects of a single exposure to an inhibitor, continuous exposure at an optimum concentration maintained a low response to glutamine. Furthermore, the treatment of the sensor with both inhibitors simultaneously resulted in a negligible response to glutamine of <1 mV, indicating that both inhibitors are necessary for optimum inhibition of glutamine response. This approach is promising as a means of enhancing the selectivity of microbial sensors.