Three R's speed response to prolonged hypoxia: rate, route, room.(Obstetrics)

SAN FRANCISCO -- Organize your thoughts when faced with complicated fetal heart rate tracings by remembering the three R's--rate, route, and room.

Clinicians commonly respond to fetal heart rate tracings suggestive of unremitting hypoxia by trying a host of routine interventions, some of which have uncertain efficacy, Michael D. Fox, R.N., said a meeting on antepartum and intrapartum management.

Random use of maternal position change, a fluid bolus, hyperoxygenation, stopping oxytocin, giving terbutaline, or stimulating the fetal scalp may dangerously delay the move to more effective interventions such as cesarean delivery, said Mr. Fox, director of the perinatal resource group at the University of California, San Francisco.

Rapid assessment of three key clinical variables speeds an effective response:

* Rate. Evaluate the fetal heat rate tracing to decide whether it's a true emergency or if further observation and conservative measures are appropriate. Reserve true "crash" C-sections for cases of sustained fetal bradycardia of 60 beats per minute (BPM) or less.

Most cases of fetal bradycardia need little or no intervention and resolve on their own, but it's difficult to tell which will be transient and which may be fatal. Even though no data support an absolute time frame for trying conservative measures, aim for delivering a fetus with bradycardia of 60 BPM or less within 10 minutes of the bradycardia reaching its nadir, Mr. Fox said at the meeting, sponsored by the university.

That means preparing to move the patient to the operating room if the bradycardia doesn't resolve within 3 minutes. Once there, surgical and anesthesia preparations can be combined while resuscitative measures continue and while waiting for the operating team to arrive.