Whole Blood Platelet Aggregation Test and Prediction of Hemostatic Difficulty After Tooth Extraction in Patients Receiving Antiplatelet Therapy

Comparison between two different local hemostatic methods for dental extractions in patients on dual antiplatelet therapy: a within-person, single-blind, randomized study

BACKGROUND

Dual antiplatelet therapy (DAPT) provides additional risk reduction of ischemic events compared to aspirin monotherapy, at cost of higher bleeding risk. There are few data comparing new techniques for reducing bleeding after dental extractions in these patients.

PURPOSE

This study investigated the effectiveness of the HemCon Dental Dressing (HDD) compared to oxidized cellulose gauze.

MATERIALS AND METHODS

This randomized study included 60 patients on DAPT who required at least two dental extractions (120 procedures). Each surgical site was randomized to HDD or oxidized regenerated cellulose gauze as the local hemostatic method. Intra-oral bleeding time was measured immediately after the dental extraction and represents our main endpoint for comparison of both hemostatic agents. Prolonged bleeding, platelet reactivity measured by Multiplate Analyser (ADPtest and ASPItest) and tissue healing comparison after 7 days were also investigated.

RESULTS

Intra-oral bleeding time was lower in HDD compared with control (2 [2-5] vs. 5 [2-8] minutes, P=0.001). Prolonged postoperative bleeding was observed in 7 cases (11.6%), all of them successfully managed with local sterile gauze pressure. More HDD treated sites presented better healing when compared with control sites [21 (36.8%) vs. 5 (8.8%), P=0.03]. There was poor correlation between platelet reactivity and intra-oral bleeding time.

CONCLUSIONS

In patients on DAPT, HDD resulted in a lower intra-oral bleeding time compared to oxidized cellulose gauze after dental extractions. Moreover, HDD also seems to improve healing conditions.

Liver protection and hemostatic effects of medicinal plant Arnebia euchroma (Royle) I.M.Johnst extract in a rat model

ETHNOPHARMACOLOGICAL RELEVANCE

Arnebia euchroma (Royle) I.M.Johnst. (AE) is a Chinese medicinal herb that is traditionally used to treat various circulatory diseases. It exhibits certain effects, such as the promotion of blood circulation and cooling, rash clearance, and detoxification.

AIM OF THE STUDY

This study was designed to explore the hepatoprotective and hemostatic effects of the ethyl acetate extract of AE in rats with carbon tetrachloride (CCl4)-induced liver injury.

MATERIALS AND METHODS

Wistar rats were treated via oral gavage with different doses of the ethyl acetate extract of AE (3.5, 7, or 14 g kg^-1·day^-1) for 14 consecutive days, following which hemostatic and liver function tests were conducted. For the hemostatic tests, the platelet count, blood platelet aggregation, blood platelet adhesion to fibrinogen, platelet factor 4 (PF-4) secretion from blood platelets, prothrombin time (PT), activated partial thromboplastin time (aPTT), thrombin time (TT), and fibrinogen levels were measured at the end of the treatment period. For the liver function tests, 0.25 mL/200 g (1.25 mL kg^-1·day^-1) of olive oil was injected into the abdominal cavity of the control rats, whereas 15% CCl₄ plus olive oil (prescription: 7.5 mL CCl₄ + 42.5 olive oil) was injected into that of the treated rats at 1 h after extract administration on day 6, 13, and 20. Additionally, food and water were withheld from all the animals. On the following day, the rats were anesthetized and their albumin, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), serum glutamic oxaloacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT), gamma-glutamyl transpeptidase (GGT), lactate dehydrogenase (LDH), reactive oxygen species (ROS), methane dicarboxylic aldehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) levels were measured. Glutathione S-transferase (GST), glutathione reductase (GR), and glutathione peroxidase (GPx) levels among the groups were determined using a one-way analysis of variance.

RESULTS

The platelet count and blood platelet aggregation, blood platelet adhesion to fibrinogen and PF-4 secretion levels were significantly increased in the (3.5 g kg^-1 day^-1) AE group as compared to those in the control group (all p < 0.001; for the 7 and 14 g kg^-1 day^-1 AE groups, all p > 0.05, respectively). Although the PT and aPTT were not affected by the AE extract (all p > 0.05), the TT was reduced and the FIB levels were significantly increased in all AE groups (p < 0.05). Liver function tests showed that CCl₄ caused significant liver damage, thereby decreasing the albumin, SOD, CAT, GSH, GST, GR, and GPx levels, while increasing the AST, ALT, ALP, SGOT, SGPT, GGT, LDH, ROS, and MDA levels (all p < 0.001). By contrast, treatment with the different doses of AE extract reversed the CCl₄ effects on all these parameters. Compared with the levels in the CCl₄ group, the GSH and GR levels in the three AE groups (3.5, 7, and 14 g kg^-1·day^-1) were significantly higher (p < 0.05, p < 0.01, and p < 0.001, respectively), whereas the differences in the other parameters for these three groups were all at the significance levels of p < 0.05, p < 0.05, and p < 0.01, respectively.

CONCLUSIONS

AE extracts administered orally exhibited hepatoprotective activity by affecting platelet production and blood coagulation and ameliorating liver function-damaging modifications. Specifically, a dosage of 3.5 g kg^-1·day^-1 resulted in the most optimal effects.

Increased Platelet Aggregation in Children and Adolescents with Sleep-disordered Breathing

Rationale: Sleep-disordered breathing (SDB) is associated with increased vascular resistance in children and adults. Persistent increased vascular resistance damages vascular endothelial cells-a marker of which is increased platelet activation.Objectives: This study compared whole-blood impedance platelet aggregation in children with clinically diagnosed SDB warranting adenotonsillectomy and healthy control subjects.Methods: Thirty children who had SDB warranting intervention clinically diagnosed by experienced pediatric otolaryngologists were recruited from adenotonsillectomy waitlists, and 20 healthy children from the community underwent overnight polysomnography to determine SDB severity (obstructive apnea-hypopnea index). Snoring frequency was collected from parents. In the morning, a fasting blood sample was taken, and whole-blood platelet aggregation was measured.Measurements and Main Results: Children with SDB exhibited increased platelet aggregation to TRAP (thrombin receptor-activating peptide) (children with SDB = 114.8 aggregation units [AU] vs. control subjects = 98.0 AU; P < 0.05) and COL antibody (96.7 vs. 82.2 AU; P < 0.05) and an increased trend in ADP antibody (82.3 vs. 69.2 AU; P < 0.07) but not aspirin dialuminate (82.1 vs. 79.5 AU; P > 0.05). No significant association was observed between either the obstructive apnea-hypopnea index and any aggregation parameter, but parental report of snoring was positively associated with TRAP aggregation (Kendall's τ-c = 0.23; P < 0.05).Conclusions: The finding of increased platelet aggregation is consistent with endothelial damage. This suggests that the profile of cardiovascular changes noted in adults with SDB may also occur in children with SDB.

Advances in Antiplatelet Therapy for Dentofacial Surgery Patients: Focus on Past and Present Strategies

BACKGROUND

Nowadays, patients involved in antiplatelet therapy required special attention during oral surgery procedures, due to the antiplatelet drugs assumption. The motivations of the assumption may be different and related to the patient's different systemic condition. For this reason, accordingly to the current international guidelines, different protocols can be followed. The aim of this work is to analyze how the dentist's approach to these patients has changed from the past to the present, evaluating the risk exposure for the patients.

METHODS

This review paper considered different published papers in literature through quoted scientific channels, going in search of "ancient" works in such a way as to highlight the differences in the protocols undertaken. The analyzed manuscripts are in the English language, taking into consideration reviews, case reports, and case series in such a way as to extrapolate a sufficient amount of data and for evaluating the past therapeutic approaches compared to those of today.

RESULTS

Colleagues in the past preferred to subject patients to substitution therapy with low molecular weight anticoagulants, by suspending antiplatelet agents to treatment patients, often for an arbitrary number of days. The new guidelines clarify everything, without highlighting an increased risk of bleeding during simple oral surgery in patients undergoing antiplatelet therapy.

CONCLUSION

Either patients take these medications for different reasons, because of cardiovascular pathologies, recent cardiovascular events, or even for simple prevention, although the latest research shows that there is no decrease of cardiovascular accidents in patients who carry out preventive therapy. Surely, it will be at the expense of the doctor to assess the patient's situation and risk according to the guidelines. For simple oral surgery, it is not necessary to stop therapy with antiplatelet agents because the risk of bleeding has not increased, and is localized to a post-extraction alveolus or to an implant preparation, compared to patients who do not carry out this therapy. From an analysis of the results it emerges that the substitutive therapy should no longer be performed and that it is possible to perform oral surgery safely in patients who take antiplatelet drugs, after a thorough medical history. Furthermore, by suspending therapy, we expose our patients to more serious risks, concerning their main pathology, where present.