How to manage influenza with Postural Orthostatic Tachycardia Syndrome (POTS)?

Managing Influenza in Patients with POTS

Patients with POTS who develop influenza require aggressive hydration and salt supplementation beyond standard flu management, with careful monitoring of heart rate and orthostatic symptoms, while avoiding medications that worsen tachycardia or hypotension.

Initial Assessment and Monitoring

When a POTS patient develops influenza, monitor vital signs more frequently than standard protocols recommend:

• Check temperature, heart rate, blood pressure (supine and standing), respiratory rate, and oxygen saturation at least twice daily 1
• Maintain oxygen saturation ≥92% and PaO2 >8 kPa if hypoxic 1
• Monitor for heart rates exceeding 120 bpm standing, which may represent POTS exacerbation rather than influenza severity alone 2, 3
• Assess for volume depletion aggressively, as fever and reduced oral intake will worsen the baseline hypovolemia common in POTS 1

A critical pitfall: Standard discharge criteria (heart rate >100/min as unstable) may not apply to POTS patients whose baseline standing heart rate often exceeds this threshold 1, 2.

Hydration and Volume Management

Increase fluid intake to 3-4 liters daily during acute illness (beyond the 2-3 liters recommended for baseline POTS management) 2. This addresses both influenza-related losses and POTS pathophysiology 2.

• Maintain salt intake at 5-10g daily through food, avoiding salt tablets to prevent gastrointestinal upset during illness 2
• Consider intravenous fluids if oral intake is inadequate, though oral fluid loading may require less volume 2
• Continue compression garments (waist-high) throughout illness to maintain venous return 2

Antiviral Therapy

Administer oseltamivir 75mg every 12 hours for 5 days if the patient presents within 48 hours of symptom onset with fever >38°C 1.

• Reduce dose to 75mg once daily if creatinine clearance <30 ml/min 1
• Consider antiviral treatment even beyond 48 hours in severely ill POTS patients, as they may be at higher risk for complications 1

Medication Management During Acute Illness

Carefully review and adjust all POTS medications during influenza:

• Continue beta-blockers (propranolol) in hyperadrenergic POTS patients, as fever and illness may worsen sympathetic overactivity 2, 4
• Maintain midodrine dosing (2.5-10mg three times daily) but monitor closely for supine hypertension, especially if febrile 2, 4
• Continue fludrocortisone in hypovolemic POTS patients, as volume expansion is critical during illness 2
• Avoid medications that worsen hypotension or tachycardia, including decongestants that may exacerbate hyperadrenergic symptoms 2, 4

Symptomatic Treatment Considerations

Use acetaminophen rather than NSAIDs for fever control when possible, as NSAIDs may affect fluid balance 1.

• Avoid topical decongestants in hyperadrenergic POTS patients, as these may worsen tachycardia 4
• Encourage rest in semi-recumbent position (head elevated 10 degrees) rather than flat supine 2
• Teach physical counter-maneuvers (leg-crossing, muscle tensing) for symptomatic orthostatic episodes during illness 2

Antibiotic Therapy if Pneumonia Develops

If pneumonia is suspected (based on clinical assessment and chest radiograph):

• Obtain blood cultures before antibiotics in severe cases (CURB-65 score ≥3) 1
• Start empirical antibiotics promptly, as POTS patients may have impaired physiologic reserve 1
• Monitor blood pressure closely when initiating antibiotics, as some agents may cause hypotension 2

Hospital Admission Criteria

Admit POTS patients with influenza if they have:

• Oxygen saturation <92% or respiratory rate >24/min 1
• Inability to maintain oral fluid intake of at least 2 liters daily 1
• Standing heart rate persistently >180 bpm (requires cardiac evaluation to exclude other arrhythmias) 2, 4
• Systolic blood pressure <90 mmHg supine 1
• Development of pneumonia with CURB-65 score ≥2 1

Post-Influenza Monitoring

POTS symptoms may worsen or newly develop after viral infections, including influenza 1, 5.

• Schedule follow-up at 2-4 weeks post-illness to reassess POTS symptom severity 2
• Monitor for new onset or worsening of orthostatic intolerance, fatigue, or cognitive symptoms 1
• Consider that 2-14% of post-viral patients may develop new or worsened POTS symptoms 5
• Reassess standing heart rate and symptom burden at follow-up visits 2

The key principle: Viral infections like influenza can trigger or exacerbate POTS 1, 5, 6, so aggressive supportive care during acute illness and careful post-illness monitoring are essential to prevent long-term worsening of autonomic dysfunction.