1. OPAT Infusion Device Modalities & Delivery Systems
Outpatient Parenteral Antimicrobial Therapy (OPAT) enables medically stable patients with serious deep-seated infections (e.g. osteomyelitis, infective endocarditis, complicated intra-abdominal sepsis) to complete extended intravenous courses in home or ambulatory infusion settings. Device selection balances precision, patient mobility, and mechanical complexity:
| Delivery Modality | Mechanism of Action | Flow Accuracy | Key Clinical Advantages | Operational Considerations |
|---|---|---|---|---|
| Elastomeric 'Balloon' Infuser | Recoil of elastomeric balloon drives fluid through micro-capillary restrictor | ±10% – 15% | Silent, lightweight, zero batteries, disposable, highly portable | Temperature-dependent flow (skin 31°C vs room 21°C); single-use cost |
| Electronic Ambulatory Pump | Rotary peristaltic or linear cassette motor delivery | ±5% | Precise intermittent dosing, audible occlusion and air alarms | Requires battery management, patient alarm education |
| Gravity Drip / Dial-A-Flow | Hydrostatic head pressure regulated by manual dial orifice | ±20% – 30% | Inexpensive, no electronic programming required | Rate shifts with arm position changes; zero occlusion alarms |
2. SASH Catheter Maintenance & Line Patency
In outpatient settings, catheter patency must be rigorously preserved using the standardized SASH protocol:
- S – Saline Flush: Flush catheter with 10 mL 0.9% preservative-free sodium chloride using push-pause pulsatile technique.
- A – Administer Medication: Connect antibiotic infuser and deliver medication at prescribed flow rate.
- S – Saline Flush: Flush with 10 mL 0.9% sodium chloride to clear all residual antimicrobial from the lumen.
- H – Heparin Lock: For non-valved catheters, instill 3 to 5 mL of Heparin lock solution (100 units/mL) with positive-pressure clamp technique to prevent fibrin reflux.
3. Therapeutic Drug Monitoring (TDM) & Laboratory Protocols
Patients receiving nephrotoxic antimicrobials at home require mandatory weekly safety laboratory monitoring:
- Vancomycin: Weekly trough concentration (target 15–20 µg/mL for complicated bacteremia/endocarditis or AUC24/MIC ratio 400–600) drawn 30 minutes prior to the 4th dose, paired with weekly serum creatinine.
- Aminoglycosides (Gentamicin, Tobramycin): Weekly peak and trough levels with serum creatinine; monitor for early signs of vestibular ototoxicity.
- Daptomycin: Weekly serum Creatine Phosphokinase (CPK) monitoring to screen for myopathy and rhabdomyolysis.