What is the most appropriate next step in managing a 67-year-old man with hypotension, tachycardia, and decreased level of consciousness, who has a history of bronchial asthma, hypertension, and myocardial infarction, and presents with fever, diarrhea, and poor oral intake?

Management of Hypotension in a 67-Year-Old Man with Confusion and Decreased Level of Consciousness

The most appropriate next step in management is an IV bolus of normal saline (option A). This patient is presenting with clear signs of hypovolemic shock secondary to diarrhea and poor oral intake, requiring immediate fluid resuscitation to restore tissue perfusion and improve hemodynamic stability.

Assessment of the Patient's Condition

The patient presents with:

• Hypotension (BP 83/45 mmHg)
• Tachycardia (HR 120/min)
• Confusion and decreased level of consciousness
• Cold extremities and feeble peripheral pulses
• History of fever, diarrhea, and poor oral intake for 2 days
• Unable to take regular medications for 2 days

These findings are consistent with hypovolemic shock due to:

• Fluid losses from diarrhea
• Decreased oral intake
• Fever (increasing insensible losses)

Rationale for IV Fluid Bolus

1. Recognition of shock state: The patient shows classic signs of hypovolemic shock including hypotension, tachycardia, cold extremities, feeble pulses, and altered mental status 1.

2. Guidelines-based approach: According to management guidelines for volume depletion, patients with moderate to severe volume depletion should receive isotonic fluids intravenously 1. The patient has at least four signs indicating moderate to severe volume depletion: confusion, dry mucous membranes (implied by poor oral intake), cold extremities, and hypotension.

3. Immediate intervention required: The ACLS tachycardia algorithm and shock management guidelines emphasize that hypotension with signs of poor perfusion requires immediate volume resuscitation before other interventions 1.

Why Other Options Are Not Appropriate

• Nasogastric tube feeding (option B): While nutrition is important, it will not address the immediate hemodynamic instability. The patient requires rapid volume expansion that can only be achieved through IV fluids.

• Intravenous beta blockers (option C): These are contraindicated in hypovolemic shock as they would worsen hypotension and decrease cardiac output. The tachycardia is a compensatory mechanism that should not be blunted until volume status is restored 1.

• Dopamine infusion (option D): While dopamine can be used in shock states, it is not the first-line treatment for hypovolemic shock 2. The FDA label for dopamine specifically states: "When appropriate, increase blood volume with whole blood or plasma until central venous pressure is 10 to 15 cm H2O or pulmonary wedge pressure is 14 to 18 mm Hg" before initiating dopamine 2. Vasopressors without adequate volume resuscitation may worsen tissue perfusion by increasing vasoconstriction in an already volume-depleted state.

Proper Fluid Resuscitation Approach

1. Initial bolus: Administer 20 mL/kg of isotonic crystalloid (normal saline) as a rapid IV bolus 1.

2. Reassessment: After the initial bolus, reassess vital signs, mental status, and signs of tissue perfusion 1.

3. Additional boluses: If signs of shock persist, consider additional fluid boluses (up to 40 mL/kg total) 1.

4. Monitor response: Look for improvements in:

   • Blood pressure
   • Heart rate
   • Mental status
   • Skin temperature
   • Urine output

Special Considerations

• Cardiac history: Despite the patient's history of hypertension and previous MI, the immediate threat is hypovolemic shock, which requires fluid resuscitation. Careful monitoring is needed due to his cardiac history, but withholding fluids would be more dangerous 1.

• Asthma history: This is relevant when considering that beta-blockers would be contraindicated, but does not affect the decision to give IV fluids.

• Medication non-adherence: While important to address, the immediate priority is treating the shock state.

Follow-up Management

After initial fluid resuscitation and stabilization:

• Investigate and treat the underlying cause of diarrhea
• Resume chronic medications as appropriate
• Consider electrolyte replacement if needed
• Monitor for fluid overload, especially given the patient's cardiac history

In summary, IV fluid bolus therapy is the most appropriate initial intervention for this patient presenting with hypovolemic shock due to diarrhea and poor oral intake.