Variations in prevalence of hypotension, hypertension, and vasopressor use in NICUs.

Objective: Very low birth weight infants are vulnerable to hypotension and its associated complications. Vasopressors are used to raise blood pressure (BP), but indications for use are uncertain. Our objectives were (1) to study variations in BP stability among NICUs, (2) to investigate inter-NICU differences in vasopressor use, and (3) to address the association between intraventricular hemorrhage (IVH) and abnormal BPs.

Variations in blood transfusions among newborn intensive care units. SNAP II Study Group.

Objectives: Very low birth weight (< 1500 g) infants frequently require packed red blood cell transfusions, and transfusion rates vary among neonatal intensive care units (NICUs). We analyzed transfusions and compared outcomes among NICUs.

Study Design: In a 6-site prospective study, we abstracted all newborns weighing < 1500 g (total = 825) born between October 1994 and September 1995.

Effect of varying inspiratory and expiratory times during high-frequency jet ventilation.

Although high-frequency jet ventilation may reduce barotrauma, the optimal ventilator settings at which complications are minimized have not been determined. To develop ventilator strategies applicable to the human infant, we studied six New Zealand rabbits before and after saline lung lavage. Changes in functional residual capacity (delta FRC) and airway pressure gradient (peak inspiratory pressure minus positive end-expiratory pressure) were measured while inspiratory time (TI) and expiratory time (TE) were varied.

Measurement of tidal volume during high-frequency jet ventilation.

The measurement of tidal volume during high-frequency jet ventilation is difficult due to the high-frequency components of the inspiratory flow. To validate tidal volume measured with a screen pneumotachograph placed on the expiratory limb, we simultaneously determined tidal volume with a body plethysmograph in seven anesthetized normal adult New Zealand rabbits before and after saline lung lavage. Four to six comparisons of tidal volume were obtained by varying peak inspiratory pressures at each combination of frequency (120, 240, and 480/min) and inspiratory to expiratory time ratio (1:1, 1:3, 1:5, 1:9).

Determination of the spectral emission of commercial flashbulbs by emission spectrographic techniques.

The relative energy distributions of the M-2, P-25, AG-1, and M-3 flashbulbs have been determined over the spectral range from 3400 A to 7600 A, using a National Bureau of Standards lamp as a spectral standard, and a Jarrell-Ash Ebert-mount spectrograph as a spectroradiometer. From these data and the blackbody radiation function, values for the color temperature of the flashbulbs have been calculated using a computer to derive a least-squares, best-fit value of color temperature.