Severe caffeine poisoning treated with intermittent hemodialysis under circulatory support

Caffeine poisoning can cause fatal ventricular arrhythmias. In this report, we describe a case of severe caffeine poisoning with extraordinarily high blood caffeine levels. Despite developing refractory ventricular fibrillation, the patient was successfully treated with intermittent hemodialysis (IHD) under circulatory support by venoarterial extracorporeal membrane oxygenation (VA-ECMO). A 22-year-old male was transported to our hospital approximately 2.5 h after ingesting 200 highly caffeinated tablets (200 mg/tablet) (40 g caffeine total) in a suicide attempt. On arrival, the patient vomited frequently with a Glasgow Coma Scale score E3V2M5, heart rate 185 beats/min, and a blood pressure of 97/62 mmHg. Shortly after arrival, the patient developed ventricular fibrillation which was refractory either to three electrical defibrillations or antiarrhythmic drugs, resulting in endotracheal intubation for mechanical ventilation and VA-ECMO. Starting from 2 h after arrival, intermittent hemodialysis (IHD) was performed for 11 h, which markedly improved clinical symptoms and circulatory parameters. Serum caffeine level was 454.9 mg/dL upon arrival at the hospital, but it decreased to 55.5 mg/dL by the end of IHD treatment. Renal replacement therapy (RRT) including intermittent hemodiafiltration, continuous hemodiafiltration, and IHD was continued because of rhabdomyolysis with myoglobinuria and secondary caused acute kidney injury. The patient was weaned off VA-ECMO on hospital day 7, extubated on hospital day 18, weaned from RRT on hospital day 46, and was transferred to another hospital for physical rehabilitation on hospital day 113. IHD under circulatory support by VA-ECMO should be considered in severe caffeine poisoning causing potentially fatal arrhythmias.

Bidirectional ventricular tachycardia induced by caffeine poisoning

Bidirectional ventricular tachycardia (BVT) is a tachyarrhythmia characterized by 180-degree beat-to-beat alteration in the QRS axis. BVT is traditionally known as an electrocardiography (ECG) finding pathognomonic of digitalis poisoning and a hallmark of catecholamine-induced ventricular tachycardia. Apart from digitalis poisoning, aconitine poisoning is the only reported cause of poisoning-related BVT, and no report of caffeine-poisoning-related BVT is as yet available. A-27-year-old woman was transported to hospital with cardiac arrest from ventricular fibrillation after taking a massive dose of a caffeine-containing supplement (corresponding to 6 g of caffeine) 6 h before presentation. Return of spontaneous circulation (ROSC) was achieved by defibrillation. She developed BVT after ROSC. Hemodialysis was performed to remove the causative drug from the blood, with subsequent resolution of BVT and hemodynamic stabilization. At presentation, she had a blood caffeine concentration of 232 μg/mL. A suggested mechanism of development of BVT is that increased intracellular calcium concentration causes delayed afterdepolarization, which induces alternate occurrence of triggered activities within different His-Purkinje fibers, and thereby produces characteristic ECG findings. Caffeine acts on the ryanodine receptor to promote calcium release from the sarcoplasmic reticulum, and thus can induce BVT via the same mechanism. Caffeine poisoning can be treated by dialysis. In cases of BVT induced by caffeine poisoning, hemodynamic stabilization can be achieved by emergency dialysis.

Plasma lactate concentration as an indicator of plasma caffeine concentration in acute caffeine poisoning

Aim

Severe caffeine poisoning is rare, but is associated with high mortality. Plasma caffeine concentration is one of the indications of treatment of caffeine poisoning; however, it is not easily measured at most emergency departments. If the plasma lactate concentration and the plasma caffeine concentration were correlated, the plasma lactate concentration may be an indication of caffeine poisoning. In this study, we investigated the correlation between the plasma lactate concentration and the plasma caffeine concentration.

Methods

From April 2010 to March 2012, 18 patients with severe caffeine poisoning by overdose were admitted at our Emergency Center. The plasma lactate concentration and plasma caffeine concentration of 10 patients were determined at the same time at 12-24 h after admission. These findings were plotted and we analyzed the correlation and trends in these concentrations.

Results

There were strong correlations between the plasma lactate concentration and the plasma caffeine concentration at admission (n = 18) and at 12-24 h after admission (n = 10) (correlation coefficients, 0.95 and 0.91, respectively). There was a strong positive correlation between the trend of the plasma lactate concentration and the plasma caffeine concentration (n = 10). The correlation coefficient was 0.91.

Conclusion

These results are extremely beneficial for emergency department clinical physicians because such findings permit the determination of the severe caffeine poisoning patient. Additionally, the plasma lactate concentration might be one of the indicators of hospitalization and discharge.