Situation: A 58-year-old woman weighing 68 kg is brought to the emergency department with fever, flank pain, and new confusion. A urinary source of infection is suspected. She has no history of heart failure or kidney disease and no known drug allergies. Sepsis-induced hypoperfusion is recognized. The physician orders a total of 30 mL/kg of balanced crystalloid to be completed within 3 hours of recognition. During the first hour she received 500 mL. At what hourly rate should the nurse set the pump to complete the remaining volume in the remaining time? Round off to the nearest whole number.

Total volume: 68 kg × 30 mL/kg = 2,040 mL. Remaining volume: 2,040 − 500 = 1,540 mL. Remaining time: 3 − 1 = 2 hours, so 1,540 ÷ 2 = 770 mL/hour. Frequent reassessment for response and fluid overload continues throughout.

Clinical calculation: 30 mL/kg crystalloid bolus in sepsis-induced hypoperfusion

This item tests whether you can translate the Surviving Sepsis Campaign–style initial resuscitation bundle into a practical infusion pump setting. The patient weighs 68 kg, and the order is 30 mL/kg of balanced crystalloid to be completed within 3 hours of recognition.

Total prescribed volume = 68 kg × 30 mL/kg = 2,040 mL. During the first hour, 500 mL was already infused. The remaining volume is 2,040 − 500 = 1,540 mL. The remaining time is 3 − 1 = 2 hours. Therefore, the hourly rate is 1,540 ÷ 2 = 770 mL/hour. The pump should be set at 770 mL/hour.

Step	Calculation	Result
Total volume ordered	68 kg × 30 mL/kg	2,040 mL
Volume already infused	First hour	500 mL
Remaining volume	2,040 − 500	1,540 mL
Remaining time	3 − 1	2 hours
Hourly pump rate	1,540 ÷ 2	770 mL/hour

Balanced crystalloid refers to solutions such as lactated Ringer’s or Plasma-Lyte, whose electrolyte composition more closely resembles plasma than normal saline does. In sepsis-induced hypoperfusion, the initial fluid bolus is intended to restore intravascular volume, improve preload, and support cardiac output before vasopressors are added or escalated.

The 30 mL/kg dose is a starting point, not a fixed total for every patient. The evidence base behind this number is strongest for patients without major cardiac or renal comorbidity, which fits this scenario because the woman has no history of heart failure or kidney disease. In a systematic review and meta-analysis of sepsis patients with heart failure, a guideline-based strategy of at least 30 mL/kg within 3 hours was compared with a restrictive approach of less than 30 mL/kg; the concern in that population is that aggressive volume may worsen congestion and outcomes ^[1]. This patient does not carry that comorbidity burden, so the full weight-based calculation is appropriate.

A large cohort study of community-onset sepsis evaluated whether receiving 30 mL/kg or more within 6 hours was associated with 30-day mortality. The authors specifically noted uncertainty about benefit in patients with severe cardiac or kidney comorbidities or intermediate lactate elevation of 18.0–36.0 mg/dL . That reinforces the clinical point: the calculation is straightforward, but the decision to give the full volume depends on reassessment and comorbidity profile.

Key point! The pump rate is not the same as the total dose. A common error is to divide the total volume by 3 hours (2,040 ÷ 3 ≈ 680 mL/hour) and choose option 1. That ignores the 500 mL already given. Always subtract the infused volume first, then divide by the remaining time.

Watch out! Reassessment must continue during and after the bolus. Fluid responsiveness is not guaranteed. In early septic shock, dynamic measures such as capillary refill time can guide whether further fluid is beneficial or harmful. The ANDROMEDA-SHOCK-2 trial used a personalized hemodynamic resuscitation protocol targeting capillary refill time in patients within the first 4 hours of septic shock, reflecting the shift toward individualized endpoints rather than a one-size-fits-all volume . Similarly, a randomized trial of early restrictive versus liberal fluid strategy in sepsis-induced hypotension assessed long-term functional outcomes, underscoring that the volume given in the first hours may affect more than just survival .

For this patient, the immediate nursing action is to set the pump at 770 mL/hour to complete the remaining 1,540 mL over 2 hours, while monitoring for signs of fluid overload such as new crackles, increased work of breathing, or rising jugular venous pressure. The presence of new confusion in the setting of fever and flank pain suggests possible urosepsis with altered mental status, which makes close neurologic and respiratory monitoring especially important during rapid volume infusion.