What is the appropriate management for a 3‑month‑old infant with pneumonia, dehydration and respiratory distress (bilateral crepitations), including need for suction, low‑flow oxygen, IV antibiotics and chest radiograph?

Management of 3-Month-Old Infant with Pneumonia, Dehydration, and Respiratory Distress

Immediate Hospitalization and Monitoring

This 3-month-old infant requires immediate hospitalization with continuous cardiorespiratory monitoring given the presence of respiratory distress (bilateral crepitations), dehydration, and young age. 1, 2

• Young infants under 3-6 months with pneumonia and signs of respiratory distress (retractions, grunting, increased work of breathing) require immediate admission to a pediatric unit with continuous cardiorespiratory monitoring capabilities. 1, 2
• The presence of dehydration is a minor criterion for severe illness that, combined with increased work of breathing, warrants close monitoring for potential ICU transfer. 3
• Vital signs including temperature, respiratory rate, heart rate, blood pressure, oxygen saturation, and mental status should be monitored at least every 4 hours initially. 1, 4

Respiratory Support

Initiate supplemental oxygen immediately via nasal cannula to maintain SpO2 >92%. 1, 4

• Low-flow oxygen (nasal cannula at 0.5-2 L/min) is typically sufficient for infants with respiratory infections and should be titrated to maintain oxygen saturation >92%. 1, 4
• Pulse oximetry should be performed and monitored continuously given the respiratory distress. 1
• Escalate to ICU if oxygen requirement reaches FiO2 ≥0.50 to maintain SpO2 >92%, or if apnea, grunting, altered mental status, or worsening respiratory distress develops. 1, 2

Diagnostic Workup

Obtain chest radiograph (posteroanterior and lateral) to confirm pneumonia, document infiltrate characteristics, and identify complications. 3, 1, 2

• Blood cultures (×2) should be obtained before starting antibiotics for moderate-to-severe pneumonia requiring hospitalization. 1, 2
• Consider viral testing (including influenza) as identification of viral pathogens can modify clinical decision-making and determine if antibacterial therapy is needed. 1
• Complete blood count with differential and C-reactive protein should be obtained for baseline assessment. 2
• Important caveat: In infants with dehydrating diarrhea, tachypnea from metabolic acidosis can mimic pneumonia; however, this infant has bilateral crepitations confirming true pulmonary involvement. 5

Antibiotic Therapy

Initiate broad-spectrum IV antibiotics immediately given the young age (3 months) and severity of presentation. 1, 6

• Young infants require broader empiric coverage due to different pathogen spectrum including Group B Streptococcus, E. coli, and other gram-negative organisms. 1
• Ampicillin-sulbactam (or similar beta-lactam/beta-lactamase inhibitor combination) is appropriate first-line therapy for hospitalized infants with pneumonia. 4
• Consider adding gentamicin for suspected gram-negative sepsis in this age group, particularly given the severity of presentation. 6
• Antimicrobial therapy may be de-escalated if viral pathogen is identified without evidence of bacterial coinfection. 1

Fluid Management and Hydration

Administer IV fluids at maintenance rate (approximately 400 mL/m²/day) to correct dehydration, with careful monitoring of intake/output. 2, 4

• Adjust IV fluid rate based on hydration status and oral intake tolerance. 2
• Monitor for signs of ongoing dehydration and ensure adequate hydration through IV route given the distressed state. 1
• Consider using 80% of maintenance fluids once rehydrated, given the risk of SIADH in pneumonia, with daily monitoring of serum electrolytes. 4

Airway Management

Perform gentle nasal suctioning as needed to clear secretions and maintain airway patency. 4

• Suction should be gentle and performed only when clinically indicated to avoid trauma and vagal stimulation. 4
• Elevate the head of the bed 30-45 degrees to facilitate breathing and reduce work of breathing. 4

Reassessment and Follow-up

Reassess clinical status every 4-6 hours for the first 24 hours, monitoring for expected improvements. 2

• Expected improvements include: decreased fever, normalized respiratory rate, reduced work of breathing, improved oxygen saturation, and improved activity level. 1, 2
• If no clinical improvement or deterioration occurs within 48-72 hours, obtain repeat chest radiograph and consider further diagnostic workup. 3, 1
• Transfer to ICU should be considered if any major criteria develop: invasive mechanical ventilation needed, fluid-refractory shock, or hypoxemia requiring FiO2 >0.50. 3

Discharge Planning

Discharge criteria include: afebrile for ≥24 hours, oxygen saturation >92% on room air, normalized respiratory rate with improved work of breathing, and ability to maintain adequate oral intake. 4

• Transition to oral antibiotics after 3 days of IV therapy if clinically improved, with total antibiotic duration of 5-7 days minimum. 4
• Close follow-up after discharge is essential to monitor for any signs of clinical deterioration. 1