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CONTEXT: Hemostatic nanoparticles (hNPs) have shown efficacy in decreasing intracerebral hemorrhage (ICH) in animal models and are suggested to be of use to counter tissue plasminogen activator (tPA)-induced acute ICH. AIMS: The objective of this study was to test the ability of an hNP preparation to alter the clotting properties of blood exposed to tPA ex vivo. MATERIALS AND METHODS: Fresh blood samples were obtained from normal male Sprague-Dawley rats (~300 g; n = 6) and prepared for coagulation assays by thromboelastography (TEG) methods. Samples were untreated, exposed to tPA, or exposed to tPA and then to hNP. TEG parameters included reaction time (R, time in minutes elapsed from test initiation to initial fibrin formation), coagulation time (K, time in minutes from R until initial clot formation), angle (α, a measure in degrees of the rate of clot formation), maximum amplitude (MA, the point when the clot reaches its MA in mm), lysis at 30 min after MA (LY30, %), and clot strength (G, dynes/cm2), an index of clot strength. STATISTICAL ANALYSIS USED: Kruskal-Wallis test was employed to compare TEG parameters measured for untreated control samples versus those exposed to tPA and to compare tPA-exposed samples to samples treated with tPA + hNPs. Significances were inferred at P ≤ 0.05. RESULTS: Compared to untreated samples, tPA-treated samples showed a trend toward decreased angle and G suggesting potentially clot formation rate and clot strength. The addition of hNP did not affect any of these or other measured indices. CONCLUSIONS: The data demonstrated no hemostatic effects when the hNP was used in the presence of tPA. The lack of change in any of the TEG parameters measured in the present study may indicate limitations of the hNPs to reverse the thrombolytic cascade initiated by tPA.
RESUMO
OBJECTIVES: Patients with cannabinoid hyperemesis syndrome (CHS) present frequently to the emergency department. Previous case studies suggest dramatic symptomatic improvement with topical capsaicin treatment. This exploratory study examined the potential effectiveness of topical capsaicin in patients with nausea and vomiting due to a suspected CHS exacerbation. METHODS: This was a double-blind, randomized placebo-controlled pilot trial. Adults who presented with vomiting suspected to be from CHS were eligible for enrollment. We excluded pregnant women and those with resolution of symptoms. Following randomization, topical 0.1% capsaicin or placebo cream was applied to the anterior abdomen in a uniform manner. The primary outcome was the severity of nausea on a visual analog scale (VAS) of 0 to 10 cm assessed at 30 minutes. Secondary outcomes were adverse events, occurrence of posttreatment vomiting, nausea by VAS at 60 minutes, and hospital admission. RESULTS: This pilot trial enrolled 30 patients, 17 in the capsaicin arm and 13 in the placebo arm. One patient in the capsaicin arm did not tolerate treatment due to skin irritation. Mean ± SD nausea severity at 30 minutes was 4.1 ± 2.3 cm in the capsaicin arm and 6.1 ± 3.3 cm in the placebo arm (difference = -2.0 cm, 95% confidence interval [CI] = 0.2 to -4.2 cm). At 60 minutes, mean ± SD nausea severity was 3.2 ± 3.2 cm versus 6.4 ± 2.8 cm (difference = -3.2 cm, 95% CI = -0.9 to -5.4 cm). The percent reduction in nausea at 60 minutes from baseline was 46.0% in the capsaicin arm and 24.9% in the placebo arm (difference = 21.1%, 95% CI = -5.6% to 47.9%). A higher proportion of capsaicin group patients (29.4% vs. 0%) had complete resolution of nausea (relative risk = 3.4, 95% CI = 1.6 to 7.1). CONCLUSION: In this pilot trial, the application of topical capsaicin cream was associated with a significant reduction in nausea at 60 minutes but not at 30 minutes and provided more complete relief of nausea.
