Massive suicidal ingestion of caffeine: a case report with investigation of the cardiovascular effect/concentration relationships.

BACKGROUND: Caffeine poisoning may cause life-threatening arrhythmias and hemodynamic failure. We aimed to investigate the toxicokinetics (TK), toxicodynamics (TD) and TK/TD relationships of caffeine in a case of poisoning. CASE REPORT: A 47-year-old male ingested pure anhydrous caffeine powder (70 g) in a suicide attempt. He developed agitation, tachycardia, and two episodes of ventricular fibrillation treated with defibrillation and tracheal intubation. He was successfully managed using intravenous infusions of esmolol and norepinephrine. METHODS: We modelled the time-course of plasma caffeine concentration (TK study using online liquid chromatography-tandem mass spectrometry), the time-course of blood lactate concentration and infusion rates of esmolol and norepinephrine (TD studies) and the TK/TD relationships. RESULTS: Caffeine TK was of first-order peaking at 258 mg/L with an elimination half-life of 46.2 h and clearance of 2.2 L/h. Caffeine-related effects on blood lactate (peak, 10 mmol/L at 1.25 h postingestion) were described by a Bateman-type equation (formation rate, 0.05 mmol/mg.h; elimination rate, 0.9 mmol/mg.h). Esmolol and norepinephrine infusion rates to reverse caffeine-related cardiovascular effects (peaks at 51-h postingestion) fitted well with a sigmoidal Emax model (EC50, 180.0 and 225.9 mg/L, respectively; Hill coefficient, 10.0). CONCLUSION: Massive caffeine ingestion is characterized by prolonged caffeine elimination. TK/TD relationships are helpful to quantify caffeine-related catecholaminergic effects.

Nail involvement in systemic sclerosis.

BACKGROUND: Nail involvement has rarely been recognized in systemic sclerosis (SSc). Indeed, only a few small series have assessed nail changes in SSc, most of which are case reports. OBJECTIVE: The aims of the current case-control study were to: (1) determine the prevalence of fingernail changes in SSc; and (2) evaluate the correlation between fingernail changes and other features of SSc. METHODS: In all, 129 patients with SSc and 80 healthy control subjects underwent routine fingernail examination. RESULTS: The prevalence of fingernail changes was 80.6% in SSc. Patients with SSc more frequently exhibited: trachyonychia (P = .006), scleronychia (P < .0001), thickened nails (P < .0001), brachyonychia (P = .0004), parrot beaking (P < .0001), pterygium inversum unguis (P < .0001), splinter hemorrhages (P < .0001), and cuticle abnormalities (P < .0001) than healthy control subjects. The presence of fingernail changes was associated with digital ulcers (P < .0001), calcinosis cutis (P = .004), and higher values of mean nailfold videocapillaroscopy score (P = .0009). LIMITATIONS: The cohort originated from a single center. CONCLUSION: This study underlines that fingernail changes are correlated with more severe forms of SSc characterized by digital microangiopathy, including digital ulcers and calcinosis cutis. Nail changes should be systematically checked in all patients with SSc, and may be included in the American College of Rheumatology/European League Against Rheumatism classification criteria for SSc.