The loss of fluid was a rare complication from a medical procedure, amniocentesis, in which a needle is inserted through the woman's abdomen to withdraw a sample of amniotic fluid for genetic tests.
Considering participants' compliance, none response and withdraw, a sample size of 100 per arm is needed.
The course of the reaction and the products were monitored by periodically withdrawing a small sample (20 μl) of the reaction mixture, which was analyzed by liquid chromatography.
At preset time intervals (2 to 10 min depending on the rate of reaction) the cumulative amount of base added is recorded and periodically 5 mL aliquots were withdrawn through a sample port fitted with a filter.
Then, the CLEAs were centrifuged off (20,000×g, 15 min), and the supernatant containing only free enzyme was withdrawn as a sample (B).
If other explanations are not ruled out, women are offered amniocentesis, in which a doctor inserts a needle into the amniotic sack that surrounds the fetus and withdraws a sample of the fluid for analysis.
Mixture quality is often assessed by withdrawing a number of samples of proscribed size and calculating the variance of the compositions.
After withdrawing an arterial blood sample, the ratio of alveolar dead space (VDA) to VT was calculated as: VDA/VT = 1 – (PETCO2/PaCO2) where PETCO2 is end-tidal CO2 measured at the plateau of the expired CO2 curve.
At 2.5, 5, 10, 20, 30, 40 and 60 min after tracer injection, continuous blood sampling was interrupted briefly to withdraw a 10-mL manual blood sample, followed by flushing of the arterial line with a heparinised saline solution.
Upon circulation of the transcripts, one participant withdrew leaving a final sample of 14 interviews for analysis.
