## 4 Discussion
### Pathologies Caused by a Reduction in the Number of Platelets
#### Idiopathic Thrombocytopenic Purpura (ITP)  
Immune thrombocytopenia, formerly known as idiopathic thrombocytopenia purpura (ITP), is an autoimmune disease related to the production of antiplatelet immunoglobulin (IgG). The production of IgG autoantibodies by B cells is critically dependent on cellular immune mechanisms, where T cells play a fundamental role in pathophysiology. T cell-mediated cytotoxicity is an alternative mechanism for platelet destruction in ITP [31; 32; 33]. Other causes include genetic factors (immune genes-FcR, immune syndromes, platelet antigens) and susceptibility to the initial event (infection, inflammation) [33]. Immune thrombocytopenia is characterized by an increased risk of mucocutaneous bleeding with a low platelet count [34; 35; 36; 37; 38]. The diagnosis of immune thrombocytopenia is made by excluding other factors that cause thrombocytopenia. The annual incidence of ITP in adults is 1.6-6.6 per 100,000 people [31; 32; 33; 34], more prevalent in women in the middle age group (30-60 years), and approximately equal for the sexes in all ages [35; 36]. The hypothesized initial cause of ITP has increased destruction of platelets at a rate that exceeds the production by the bone marrow. Recently, new evidence has called this model into question, since platelet production is decreased in many ITP patients [36]. There is no \"gold standard\" test that reliably establishes the diagnosis. However, a positive response to specific ITP therapy, such as intravenous immunoglobulins and/or steroids, supports the diagnosis. The phases of the disease have been redefined:  
1. Newly diagnosed ITP: within 3 months after diagnosis;
2. Persistent ITP between 3 and 12 months after diagnosis;
3. Chronic ITP lasting more than 12 months. The primary goal of treating ITP is the prevention of major bleeding events by achieving a safe platelet count, without returning the platelet count to normal. A level of \(50\times 10^{9}/\upmu\)L may be sufficient in ITP patients with well-functioning platelets. Adults with platelet counts below \(30\times 10^{9}/\upmu\)L are usually treated. Several large cohort studies have reported that patients with platelet counts above this level have been observed safely without treatment [37]. The incidence of bleeding diathesis increases with age, and the effect of this condition on quality of life, mortality, and morbidity should be considered. Studies of comorbidities and risk factors in a large series of ITP patients with long follow-ups are rare [37]. Surgical complication and mortality studies were only conducted for splenectomy procedures. The overall characteristics of adverse postoperative outcomes for ITP patients undergoing all types of surgical procedures have not been studied in a population-based cohort [38]. The risk of fatal bleeding is generally very low. Risk factors for serious bleeding include elderly age, bleeding diseases (>65 years with a previous history of bleeding, gastrointestinal problems, liver cirrhosis, controlled hypertension), and specific drugs (aspirin, Coumadin, NSAIDs, etc.) [38]. In the case of dental procedures, transfusions of platelet concentrates should be considered when the platelet count falls under [38]:  
* 20-30 \(\times\) 10\({}^{9}/\upmu\)L Dentistry (calculus removal, root planning)
* 30 \(\times\) 10\({}^{9}/\upmu\)L during simple extractions
* 50 \(\times\) 10\({}^{9}/\upmu\)L during complex extractions
* 30 \(\times\) 10\({}^{9}/\upmu\)L during locoregional (troncular) anaesthesia
* 50 \(\times\) 10\({}^{9}/\upmu\)L during small dental surgery
* 80 \(\times\) 10\({}^{9}/\upmu\)L during major dental surgery (complex interventions)  
Outpatient anaesthesia can be performed in ITP patients with normal preoperative examinations without further haemostasis issues [37; 38]. Outpatient anaesthesia can be performed in ITP patients with normal preoperative examinations without further haemostasis issues [37; 38].