Kidney Week

Abstract: SA-PO0322

High-Dose Continuous Venovenous Hemodiafiltration for Severe Phenobarbital Intoxication in a Hemodynamically Unstable Patient

Session Information

• AKI: Epidemiology and Risk Factors
  October 24, 2026 | Location: Exhibit Hall A, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Acute Kidney Injury

• 101 AKI: Epidemiology, Risk Factors, and Prevention

Authors

• Tanzarella, Elena, Universita Vita Salute San Raffaele, Milan, Lombardy, Italy

Elena Tanzarella, MD

• Cocchini, Lorenzo, IRCCS Ospedale San Raffaele, Milan, Lombardy, Italy

Lorenzo Cocchini, MD

• Foligno, Nadia Edvige, IRCCS Ospedale San Raffaele, Milan, Lombardy, Italy

Nadia Edvige Foligno, MD

• Vezzoli, Giuseppe, IRCCS Ospedale San Raffaele, Milan, Lombardy, Italy

Giuseppe Vezzoli, MD

• Barruscotti, Alessandro, IRCCS Ospedale San Raffaele, Milan, Lombardy, Italy

Alessandro Barruscotti

• Sciarrone Alibrandi, Maria Teresa, IRCCS Ospedale San Raffaele, Milan, Lombardy, Italy

Maria Teresa Sciarrone Alibrandi

• Lanzani, Chiara, IRCCS Ospedale San Raffaele, Milan, Lombardy, Italy

Chiara Lanzani, MD

• Simonini, Marco, IRCCS Ospedale San Raffaele, Milan, Lombardy, Italy

Marco Simonini, MD

Introduction

Phenobarbital is a long-acting barbiturate with moderate protein binding and a relatively large volume of distribution. In severe intoxications, extracorporeal removal may be indicated. Intermittent hemodialysis (IHD) is recommended as first-line therapy due to its high clearance efficiency; however, hemodynamic instability may limit its feasibility. In such cases, continuous kidney replacement therapy (CKRT) may represent a suitable alternative.

Case Description

A 64-year-old man (80 kg) was admitted to the ICU after being found unconscious. GCS was 3, requiring intubation and mechanical ventilation. Severe hemodynamic instability required vasopressor support. Toxicological screening revealed phenobarbital intoxication (serum level 121.7 µg/mL; therapeutic range 10–40 µg/mL). Due to inadequate response to conservative management and persistent hemodynamic instability, continuous venovenous hemodiafiltration (CVVHDF) was initiated via jugular catheter using a PRISMAflex system (AV1000S, 1.8 m² polysulfone membrane). Blood flow was 150 mL/min, dialysate flow 2.6 L/h, pre-dilution replacement fluid 1.0 L/h; total effluent flow 3.6 L/h (delivered dose 45 mL/kg/h). Anticoagulation was maintained with unfractionated heparin. Neurological and hemodynamic improvement was observed after approximately 8 hours (phenobarbital 27.5 µg/mL). CVVHDF was continued for 38 hours and 40 minutes, achieving a level of 11.2 µg/mL, with no post-discontinuation rebound. The patient recovered fully and was discharged home in good condition.

Discussion

Current EXTRIP guidelines recommend IHD as the preferred extracorporeal treatment for severe phenobarbital intoxication; however, data on CKRT in this setting remain scarce. This case documents the successful use of high-dose CVVHDF as primary extracorporeal treatment in a patient with marked hemodynamic instability where IHD was not feasible. It highlights how individualized treatment, based on toxicokinetic properties and patient-specific conditions, may be more relevant than strict adherence to modality hierarchy. High-dose CVVHDF provided sustained drug removal, prevented rebound, and led to full recovery, representing an effective and safe alternative when intermittent techniques are contraindicated.