For which finding should a nurse withhold labetalol from a client with preeclampsia?

Labetalol is a medication commonly used to manage hypertension, especially in pregnant clients with preeclampsia. It is a non-selective beta-blocker that can have effects on heart rate and blood pressure. In this scenario, the heart rate of 54 beats per minute is a critical finding that would warrant withholding labetalol.

Bradycardia, defined as a heart rate below 60 beats per minute, can be exacerbated by beta-blockers like labetalol. Using this medication in a patient with a significantly low heart rate could risk further decreasing cardiac output and may lead to adverse effects.

In contrast, a blood pressure of 140/90 mmHg may indicate mild hypertension but does not immediately necessitate withholding labetalol, especially if the patient requires antihypertensive management to prevent complications associated with preeclampsia. The respiratory rate and oxygen saturation levels are within normal limits, suggesting no imminent respiratory distress or hypoxia, which would typically warrant reconsideration of medication. Therefore, the heart rate is the most critical factor in determining the safety of administering labetalol in this context.