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J L Rau

Publications and source records attributed to J L Rau.

6 recordsLinked to original sources
PubMed1992

Evaluation of a reservoir device for metered-dose bronchodilator delivery to intubated adults. An in vitro study.

UNLABELLED: We investigated the use of a reservoir device for delivery of a MDI bronchodilator aerosol using a lung model of an intubated, mechanically ventilated adult. METHODS: Albuterol (Proventil) was delivered with a MDI using three methods. In method 1, the MDI was attached directly onto the ETT using a commercially available actuator/adapter. In method 2, the Monaghan AeroVent reservoir was placed on the inspiratory limb of the ventilator circuit just before the patient Y connector. In method 3, the AeroVent was placed between the patient Y connector and the ETT. Standardized ventilator settings with a Servo 900C were used for all three methods (VE = 9.6 L; respiratory rate = 12 breaths per minute; TI = 20 percent of 1 s). Aerosol drug delivery was measured at the distal tip of the ETT using a spectrophotometric technique. Percentage of amount delivered was calculated from measured delivery of the MDI. RESULTS: The MDI directly on the ETT delivered 7.3 percent of the total dose to the end of the ETT. The AeroVent on the inspiratory limb increased this to 32.1 percent and the AeroVent between the Y connector and the ETT delivered 29 percent. Both reservoir delivery methods delivered significantly more drug than direct placement of the MDI on the ETT (p less than 0.01) but did not differ from each other (p greater than 0.05). CONCLUSIONS: Use of the AeroVent reservoir chamber significantly increased bronchodilator delivery by aerosol with an MDI in an adult lung model of an intubated patient on ventilatory support.

Adult↗
PubMed1985

Quantitative buffy coat analysis. A hematologic screen applicable to the selection of apheresis donors.

Quantitative buffy coat analysis was performed on samples of venous blood with the QBC (Clay Adams Division of Becton Dickinson, Rutherford, NJ) Hematology System and the results for platelet counts, white blood cell counts, and microhematocrits were compared with those obtained by reference methods. At the established cut-off, values for apheresis donors the with-in run reproducibility (CV) of the platelet count was 6.8%; of the white blood cell count, 8.6%; and of the microhematocrit, 1.75%. Over the range of values studied, the platelet count showed the poorest correlation with the reference method (R = 0.72023) and the greatest dispersion of QBC values at a given reference value. Correlation coefficients for QBC and reference methods for white blood cell counts and hematocrits were 0.88887 and 0.89778, respectively. Predicted ranges of reference values for platelet counts and white blood cell counts, based on QBC measurements, were too wide at lower levels of the normal range to be clinically meaningful. When used in a screening mode to determine if results from apheresis donors exceeded specific cut-off values, the QBC system performed well as determined by high predictive values for results above the selected cut-offs. Misclassification errors with the QBC system were more likely to result in rejection of acceptable donors than acceptance of those with low platelet or white cell counts.

Blood Cell Count↗
PubMedDate not supplied

A comparison of the effects of assist-control, SIMV, and SIMV with pressure support on ventilation, oxygen consumption, and ventilatory equivalent.

OBJECTIVE: To quantify the ventilatory efficiency of different modes of mechanical ventilation used to achieve full ventilatory support in normal subjects. Modes compared were assist-control, synchronized intermittent mandatory ventilation (SIMV), and SIMV with 10 cm H2O (0.98 kPA) of pressure support. DESIGN: Prospective, randomized blocks repeated measures design. Subjects served as their own controls. SETTING: A university affiliated pulmonary laboratory. SUBJECTS: Ten healthy volunteers, aged 31-54 years. OUTCOME MEASURES: Minute volume, respiratory rate, average tidal volume, oxygen consumption, and ventilatory equivalent. INTERVENTION: Baseline spontaneous ventilation data collection was followed by mechanical ventilation by mouthpiece in each of three modes in a random sequence. All modes used a machine set rate of 12 breaths per minute, VT of 10 cc/kg of ideal body weight, inspiratory time of 1 second, square wave flow pattern and a sensitivity of -1 cm H2O (-0.09806 kPa) to achieve full ventilatory support. Data were collected continuously for 5 minutes and the mean values were reported. Ventilatory equivalent for oxygen is a measure of the efficiency of the ventilatory pump at various work loads and was calculated by dividing VE (BTPS) by the VO2 (STPD). RESULTS: There were significant differences by mode of mechanical ventilation in average tidal volume (p = 0.02), minute volume (p = 0.02), oxygen consumption (p = 0.04), and ventilatory equivalent (p = 0.01) using ANOVA. There was no significant difference (p = 0.66) by mode of ventilation in respiratory rate. Pairwise follow-up comparisons for these variables found that SIMV with pressure support produced a significantly greater average tidal volume, minute volume, oxygen consumption, and ventilatory equivalent than SIMV alone. SIMV with pressure support also produced a significantly greater minute volume and ventilatory equivalent than assist-control. There were no significant differences between assist-control and SIMV. All three modes produced a lower ventilatory equivalent and higher oxygen consumption than spontaneous breathing. CONCLUSIONS: SIMV with pressure support significantly increased minute volume and ventilatory equivalent when compared with assist-control or SIMV alone, and thus was the most efficient mode of full ventilatory support for our subjects. We found no difference in ventilatory efficiency between assist-control and SIMV. All three mechanical modes were less efficient for our subjects than spontaneous breathing. The inspiratory time of 1 second used in this study, although common in clinical practice, may be inadequate for some patients.

Adult↗