Effect of Pneumatic Tubing System Transport on Platelet Apheresis Units.

Platelet apheresis units are transfused into patients to mitigate or prevent bleeding. In a hospital, platelet apheresis units are transported from the transfusion service to the healthcare teams via two methods: a pneumatic tubing system (PTS) or ambulatory transport. Whether PTS transport affects the activity and utility of platelet apheresis units is unclear. We quantified the gravitational forces and transport time associated with PTS and ambulatory transport within our hospital. Washed platelets and supernatants were prepared from platelet apheresis units prior to transport as well as following ambulatory or PTS transport. For each group, we compared resting and agonist-induced platelet activity and platelet aggregate formation on collagen or von Willebrand factor (VWF) under shear, platelet VWF-receptor expression and VWF multimer levels. Subjection of platelet apheresis units to rapid acceleration/deceleration forces during PTS transport did not pre-activate platelets or their ability to activate in response to platelet agonists as compared to ambulatory transport. Platelets within platelet apheresis units transported via PTS retained their ability to adhere to surfaces of VWF and collagen under shear, although platelet aggregation on collagen and VWF was diminished as compared to ambulatory transport. VWF multimer levels and platelet GPIb receptor expression was unaffected by PTS transport as compared to ambulatory transport. Subjection of platelet apheresis units to PTS transport did not significantly affect the baseline or agonist-induced levels of platelet activation as compared to ambulatory transport. Our case study suggests that PTS transport may not significantly affect the hemostatic potential of platelets within platelet apheresis units.

Assessment of three point-of-care platelet function assays in adult trauma patients.

BACKGROUND: Antiplatelet (AP) medication use is common among trauma patients and is associated with poor outcomes. Management options for platelet dysfunction in trauma patients are controversial, expensive, and potentially harmful. Although light transmission platelet aggregometry is considered the standard test to assess platelet function, it is cumbersome and not generally available. Currently, there are no widely accepted platelet function point-of-care tests for acute trauma. STUDY DESIGN: Prospective observational study from 2014 to 2015. Baseline Multiplate aggregometry aspirin area under the platelet aggregation curve (ASPI AUC), Thrombelastography Platelet Mapping percent inhibition of arachidonic acid (TEG-PM AA), and VerifyNow Aspirin Test (ARU) were compared for ability to detect any AP medication use (aspirin or clopidogrel), platelet dysfunction, and identify patients at risk for intracranial hemorrhage (ICH) progression by calculating the area under receiver operating characteristic curves (AUC), sensitivity, specificity, and positive and negative predictive values. Adenosine diphosphate assays were similarly evaluated. RESULTS: Sixty-four patients were enrolled, 25 were taking AP medications. AP patients were older (71.6 versus 35.0 y, P < 0.001) and received more platelet transfusions, but other baseline characteristics were similar. Median ASPI AUC (22.0 versus 53.5 P < 0.001) and VerifyNow ARU (503.5 versus 629.0, P < 0.001) were lower, whereas TEG-PM AA (51.8% versus 18.3%, P < 0.001) was higher in AP patients. Multiplate ASPI AUC, TEG-PM AA percent inhibition, and VerifyNow ARU could identify AP medication use (AUC: 0.90, 0.77, and 0.90, respectively). Adenosine diphosphate assays did not correlate with AP medication use in this population. TEG-PM AA percent inhibition and VerifyNow ARU correlated well with Multiplate ASPI AUC to identify platelet dysfunction (AUC: 0.78, 0.89, respectively). ICH occurred in 29 patients; 12 of which had progression of their injury. ASPI AUC (AUC: 0.50) and VerifyNow ARU (AUC: 0.59) did not correlate, and TEG-PM AA percent inhibition (AUC: 0.66) minimally correlated with progression. CONCLUSIONS: Multiplate, TEG-PM, and VerifyNow are useful point-of-care tests which identify AP medication use and platelet dysfunction in trauma patients. Initial TEG-PM AA percent inhibition may be associated with risk for ICH progression. However, additional large, prospective studies are needed.

Comparison of the hemostatic efficacy of low-volume lyophilized plasma reconstituted using sterile water, lactated Ringer's, normal saline, and Hextend solutions.

BACKGROUND: Low-volume ascorbic acid-buffered reconstituted lyophilized plasma (LP) provides logistic advantages, reduces the risks for large-volume resuscitation, modulates inflammation, and is equally effective for hemostatic resuscitation as full-volume LP. We compared the physiologic effects of resuscitation using LP reconstituted with sterile water (LP-SW), lactated Ringer's solution (LP-LR), normal saline (LP-NS), and Hextend (LP-Hx). METHODS: Plasma was collected from swine, lyophilized, and then reconstituted into four test solutions: LP-SW, LP-LR, LP-NS, or LP-Hx. Forty swine were anesthetized and subjected to a validated model of polytrauma and hemorrhagic shock (including a Grade V liver injury), then randomized to receive one of the four test solutions. Physiologic parameters, blood loss, lactate, and hematocrit were followed up. Coagulation status was evaluated using thrombelastography. Inflammatory mediator expression was evaluated by multiplex serum assay. RESULTS: Forty animals were included in the study (10 animals per group). One animal died following LP-Hx resuscitation. There was less blood loss in the LP-SW and LP-LR groups compared with the LP-NS and LP-Hx groups (p < 0.05). The LP-SW group exhibited less early coagulopathic changes by thrombelastography, and the LP-Hx group had persistently elevated international normalized ratios at the end of the study period (p < 0.05). Serum interleukin 6 was lower after 4 hours in the LP-SW group compared with LP-NS (p < 0.05). CONCLUSION: Resuscitation using low-volume LP-SW and LP-LR buffered with ascorbic acid confers an anti-inflammatory benefit and results in less blood loss. Sterile water is a safe, cost-effective, and universally available fluid for creating a low-volume hemostatic LP resuscitation solution.