A client is admitted to the critical care unit (CCU) with a third degree complete heart block. A temporary transvenous pacemaker is inserted by the healthcare provider (HCP). An hour after pacemaker insertion, the device stops sensing the client's intrinsic heart rate. Which action should the nurse implement first?

A. White blood cell differential. Although infection is a common precipitating factor for DKA, an elevated WBC count is common in DKA due to stress, dehydration, and inflammation rather than infection itself. While a WBC differential may be done if infection is suspected, it is not a primary test for DKA management.
B. Hemoglobin A1C. Hemoglobin A1C (HbA1c) reflects long-term glucose control (past 2-3 months) but does not provide immediate information about the current metabolic status or severity of DKA. While it may be useful in assessing overall diabetes management, it is not essential for acute DKA treatment.
C. Serum electrolytes. Patients with DKA experience significant electrolyte imbalances, particularly potassium depletion due to osmotic diuresis and insulin deficiency. Monitoring serum sodium, potassium, and bicarbonate is crucial for guiding fluid and electrolyte replacement therapy. Potassium levels may appear normal or high initially due to acidosis but typically drop with insulin administration.
D. Urine culture. A urine culture is only indicated if a urinary tract infection (UTI) is suspected as a trigger for DKA. However, routine urine culture is not required in every case of DKA unless there are symptoms of infection such as fever, dysuria, or pyuria.
E. Anion gap. DKA is a form of high anion gap metabolic acidosis, caused by the accumulation of ketones. The anion gap (AG) is calculated as (Na⁺ - [Cl⁻ + HCO₃⁻]), with a value >12 mEq/L indicating metabolic acidosis. Monitoring the anion gap helps assess the severity of acidosis and guide treatment progress, as a decreasing anion gap suggests resolution of ketosis.
F. Urine ketones. Urine ketone testing helps confirm the presence of ketoacidosis, particularly in the initial stages of DKA diagnosis. While serum beta-hydroxybutyrate is a more accurate indicator of ketone levels, urine ketones remain useful for initial screening and monitoring treatment response as they decrease with appropriate management.

A. View the rhythm in another chest lead. While verifying the rhythm in another lead may help confirm the accuracy of the monitor, it does not address the immediate absence of a pulse and respirations. The client is in pulseless electrical activity (PEA), which requires immediate intervention rather than rhythm verification.
B. Begin chest compressions at a rate of 120 times a minute. The client has no palpable carotid pulse and no spontaneous respirations despite a sinus rhythm on the monitor, indicating pulseless electrical activity (PEA). PEA is a form of cardiac arrest where the heart shows electrical activity but fails to generate effective circulation. Immediate high-quality chest compressions are essential to maintain perfusion while addressing the underlying cause, such as hypovolemia or tension pneumothorax.
C. Auscultate all chest fields for muffled lung sounds. While assessing for muffled lung sounds may help detect conditions such as tension pneumothorax or hemothorax, it should not delay the initiation of CPR. Once compressions are started, the underlying cause of PEA can be investigated.
D. Observe for swelling at the fracture site. Swelling at the fracture site may indicate bleeding or compartment syndrome, but assessing the fracture should not take priority over initiating CPR. If hemorrhage is suspected as a cause of PEA, rapid fluid resuscitation should be initiated after starting chest compressions.