A 65-year-old patient with a history of diabetes is admitted with persistent vomiting for the past 24 hours. The patient appears lethargic, has dry mucous membranes, and decreased skin turgor. Vital signs are: temperature 99.2°F (37.3°C), heart rate 110 bpm, respiratory rate 22/min, blood pressure 100/60 mmHg. What is the priority nursing intervention?

IV fluid therapy is priority for severe dehydration with persistent vomiting to restore intravascular volume and prevent shock. Oral antiemetics or fluids are ineffective due to vomiting.

Clinical Presentation Analysis
The patient presents with persistent vomiting for 24 hours, lethargy, dry mucous membranes, decreased skin turgor, tachycardia (heart rate 110 bpm), and relative hypotension (BP 100/60 mmHg). This constellation of findings indicates significant fluid volume deficit secondary to gastrointestinal losses. The history of diabetes adds risk because hyperglycemia can induce osmotic diuresis, compounding the hypovolemia. The elevated heart rate is a compensatory mechanism to maintain cardiac output in the setting of decreased intravascular volume, and the borderline low blood pressure signals that compensatory mechanisms are beginning to fail, placing the patient at risk for progression to hypovolemic shock.

Pathophysiology of Hypovolemic Shock
Hypovolemic shock is a life-threatening condition resulting from a significant reduction in intravascular volume, which impairs oxygen delivery to vital organs. As described in the evidence synthesis by Wang et al., common causes include fluid loss from the gastrointestinal tract, such as persistent vomiting ^[1]. The underlying mechanism involves decreased preload, leading to reduced stroke volume and cardiac output. The body initially compensates with sympathetic nervous system activation, producing tachycardia and vasoconstriction. However, when volume loss exceeds the body's compensatory capacity, tissue hypoperfusion, cellular hypoxia, and eventual organ failure occur. The nurse's role in early recognition of these compensatory signs—tachycardia, decreased skin turgor, dry mucous membranes—is critical to prevent decompensation ^[1].

Priority Intervention: Fluid Resuscitation
The priority nursing intervention is to initiate intravenous fluid therapy as ordered. The evidence-based review by Wang et al. emphasizes that prompt fluid resuscitation is critical in managing hypovolemic shock, with nurses playing a central role in timely intervention ^[1]. Intravenous access and isotonic crystalloid administration directly address the core problem of intravascular volume depletion by restoring circulating volume, improving preload, and enhancing tissue perfusion. In this scenario, the patient's oral route is compromised due to persistent vomiting, making oral rehydration attempts ineffective and potentially dangerous due to aspiration risk. Administering an oral antiemetic is contraindicated when the patient is actively vomiting and has an unsecured airway. Positioning in high Fowler's position could worsen hypotension by reducing venous return. Therefore, establishing IV access and beginning fluid resuscitation is the immediate, evidence-based nursing action that aligns with the best practices for managing evolving hypovolemic shock ^[1].