Reversal of Warfarin-Associated Major Hemorrhage: Activated Prothrombin Complex Concentrate versus 4-Factor Prothrombin Complex Concentrate

BACKGROUND: Warfarin-associated major hemorrhage is frequently treated with prothrombin complex concentrates to correct international normalized ratio (INR). OBJECTIVE: This article aims to investigate the efficacy of activated prothrombin complex concentrate (aPCC) versus 4-factor prothrombin complex concentrate (4PCC) for vitamin K antagonist reversal in patients with warfarin-associated major hemorrhage. MATERIALS AND METHODS: This was a multicenter, retrospective cohort study. Patients included were age ≥ 18 years with pretreatment INR of \u3e 1.5. Exclusion criteria were patients treated for urgent procedures without hemorrhage, treated but not taking warfarin, unavailable INR values, and pregnant patients. Patients were stratified into two groups: aPCC or 4PCC. The primary outcome was achievement of INR ≤ 1.5 at the posttreatment INR sampling. Secondary outcomes focused on thrombotic events and mortality. RESULTS: Of 342 patients, 237 patients received aPCC and 105 patients received 4PCC. After 1:1 propensity score matching, 86 patients remained in each group. In the matched cohort, the proportion of patients who achieved target INR ≤ 1.5 was greater with 4PCC (aPCC = 61 [70.9%] vs. 4PCC = 76 [88.4%]; 95% confidence interval [CI] -29.2% to -5.7%) and groups had comparable in-hospital thrombotic events and mortality. In the unmatched cohort, achievement of target INR ≤ 1.5 was greater with 4PCC (aPCC = 151 [63.7%] vs. 4PCC = 92 [87.6%]; 95% CI -32.7% to -15.1%). CONCLUSION: In the treatment of warfarin-associated major hemorrhage, 4PCC compared with aPCC was associated with greater achievement of INR ≤ 1.5 with comparable thrombotic events and mortality. Further controlled studies are needed to confirm these findings and determine the optimal dosing strategy that maximizes efficacy and safety

Microbial Control of Sea Spray Aerosol Composition: A Tale of Two Blooms.

With the oceans covering 71% of the Earth, sea spray aerosol (SSA) particles profoundly impact climate through their ability to scatter solar radiation and serve as seeds for cloud formation. The climate properties can change when sea salt particles become mixed with insoluble organic material formed in ocean regions with phytoplankton blooms. Currently, the extent to which SSA chemical composition and climate properties are altered by biological processes in the ocean is uncertain. To better understand the factors controlling SSA composition, we carried out a mesocosm study in an isolated ocean-atmosphere facility containing 3,400 gallons of natural seawater. Over the course of the study, two successive phytoplankton blooms resulted in SSA with vastly different composition and properties. During the first bloom, aliphatic-rich organics were enhanced in submicron SSA and tracked the abundance of phytoplankton as indicated by chlorophyll-a concentrations. In contrast, the second bloom showed no enhancement of organic species in submicron particles. A concurrent increase in ice nucleating SSA particles was also observed only during the first bloom. Analysis of the temporal variability in the concentration of aliphatic-rich organic species, using a kinetic model, suggests that the observed enhancement in SSA organic content is set by a delicate balance between the rate of phytoplankton primary production of labile lipids and enzymatic induced degradation. This study establishes a mechanistic framework indicating that biological processes in the ocean and SSA chemical composition are coupled not simply by ocean chlorophyll-a concentrations, but are modulated by microbial degradation processes. This work provides unique insight into the biological, chemical, and physical processes that control SSA chemical composition, that when properly accounted for may explain the observed differences in SSA composition between field studies

Microbial Control of Sea Spray Aerosol Composition: A Tale of Two Blooms

With the oceans covering 71% of the Earth, sea spray aerosol (SSA) particles profoundly impact climate through their ability to scatter solar radiation and serve as seeds for cloud formation. The climate properties can change when sea salt particles become mixed with insoluble organic material formed in ocean regions with phytoplankton blooms. Currently, the extent to which SSA chemical composition and climate properties are altered by biological processes in the ocean is uncertain. To better understand the factors controlling SSA composition, we carried out a mesocosm study in an isolated ocean-atmosphere facility containing 3,400 gallons of natural seawater. Over the course of the study, two successive phytoplankton blooms resulted in SSA with vastly different composition and properties. During the first bloom, aliphatic-rich organics were enhanced in submicron SSA and tracked the abundance of phytoplankton as indicated by chlorophyll-a concentrations. In contrast, the second bloom showed no enhancement of organic species in submicron particles. A concurrent increase in ice nucleating SSA particles was also observed only during the first bloom. Analysis of the temporal variability in the concentration of aliphatic-rich organic species, using a kinetic model, suggests that the observed enhancement in SSA organic content is set by a delicate balance between the rate of phytoplankton primary production of labile lipids and enzymatic induced degradation. This study establishes a mechanistic framework indicating that biological processes in the ocean and SSA chemical composition are coupled not simply by ocean chlorophyll-a concentrations, but are modulated by microbial degradation processes. This work provides unique insight into the biological, chemical, and physical processes that control SSA chemical composition, that when properly accounted for may explain the observed differences in SSA composition between field studies