A client with acute respiratory distress syndrome (ARDS) shows no improvement despite increases in concentration in oxygen administered. What intervention should the nurse attempt which may improve ventilation-perfusion matching?

A The first intervention should be to ensure adequate oxygenation, as hypoxia can exacerbate shock. Therefore, providing oxygen at 100% via a non-rebreather mask is the most critical initial step. This intervention helps to maximize the amount of oxygen delivered to the patient's lungs and subsequently to the rest of the body, supporting vital organ function while further assessments and interventions are prepared.

B Continuous ECG monitoring allows for the assessment of the patient's heart rhythm, rate, and any signs of dysrhythmias or cardiac ischemia. This intervention is important for detecting any life- threatening arrhythmias, such as ventricular tachycardia or fibrillation, which may require immediate intervention. While ECG monitoring is important, it may not be the highest priority intervention.

C Drawing blood for type and crossmatch is important for preparing for potential blood transfusions if significant blood loss is suspected. However, this intervention may take some time to process, and immediate stabilization of the patient's condition is paramount.

D Large-bore IV catheters allow for rapid infusion of fluids to restore intravascular volume and improve tissue perfusion. This intervention is critical for stabilizing the patient's hemodynamic status and takes precedence in the management of shock. However, oxygenation should take priority.

C. Mean arterial pressure (MAP) reflects the average pressure in the arteries during one cardiac cycle and is an important indicator of tissue perfusion. A MAP of 56 mm Hg is below the normal range (typically >60 mm Hg) and may indicate inadequate tissue perfusion. While norepinephrine is commonly used to increase blood pressure and improve tissue perfusion in hypotensive patients, a MAP of 56 mm Hg suggests that the current infusion rate may not be sufficient to maintain adequate perfusion, and adjusting the infusion rate may be warranted.

A. Norepinephrine is a vasopressor medication primarily used to increase blood pressure in patients with hypotension or shock. A low pulmonary artery wedge pressure (PAWP) suggests decreased preload, which may indicate hypovolemia or inadequate fluid resuscitation. In this case, adjusting the norepinephrine infusion rate may not be necessary, but rather addressing the underlying cause of hypovolemia or inadequate preload.

B. Systemic vascular resistance (SVR) represents the resistance the heart must overcome to pump blood into the systemic circulation. An elevated SVR may suggest vasoconstriction, which could be a desired effect of norepinephrine infusion to increase blood pressure. Therefore, an elevated SVR may not necessarily indicate a need to adjust the norepinephrine infusion rate, as it may reflect the medication's intended action.

D. Norepinephrine primarily acts on alpha-adrenergic receptors to increase blood pressure by inducing vasoconstriction. While it may cause reflex bradycardia due to increased systemic vascular resistance, a heart rate of 58 beats/min may be within an acceptable range depending on the patient's clinical condition and baseline heart rate. Therefore, a slow heart rate alone may not necessarily indicate a need to adjust the norepinephrine infusion rate unless it is associated with signs of inadequate tissue perfusion or other concerning symptoms.