Final answer:
The nurse should consider administering steroids to enhance fetal lung development due to the high risk of IRDS associated with a low L/S ratio, monitor fetal heart rate, and take measures to prevent infection while avoiding harmful actions.
Step-by-step explanation:
The actions that a nurse should take when caring for a pregnant client at 33 weeks' gestation with premature rupture of the membranes (PROM) and with a lecithin/sphingomyelin (L/S) ratio of 1.5 include several important steps to ensure the safety of both the mother and the infant. First and foremost, with an L/S ratio of less than 1.5, there is a high risk of infant respiratory distress syndrome (IRDS), therefore, the administration of steroids to the mother to speed up fetal lung development may be necessary. Monitoring the fetal heart rate for any signs of distress is critical, and in this scenario, the fetal heart rate of 134 beats per minute with variability is a normal finding.
Should evidence of fetal distress or infection arise, more immediate interventions, such as delivery, may be warranted. In the absence of indications for delivery, measures to prevent infection, such as administering antibiotics, and close monitoring of the mother and fetus, constitute appropriate management. It is of the utmost importance to avoid any actions that could potentially harm the client or the fetus.