Courtly Platelets and Lady-in-Waiting Concerns

Because the Countess showed a low platelet count of 11 from Tuesday's test, though her Hg was up to 9.6, and the Lady-in-Waiting is coping with "flying blind" in this situation, the Page, still in absentia from Court, has found the following information (source links provided after each bit) to help her and the Countess.

The general conclusion from the various sources is that, barring evidence of unprovoked bleeding, platelet transfusions are indicated only when the counts fall below 5; they may be given for counts under 10 if general condition gives the treating physician cause for concern.

In other words, unless the counts today, when the Countess visits her physician in the company of the Lady-in-Waiting, have fallen at least below 10, there is NO reason to be alarmed and NO transfusion of platelets will likely be deemed necessary.

Here follow some quotes from various sources, as indicated, on the platelet levels used as indicators for transfusions:

Platelets

While there is some debate regarding the appropriate use of platelet transfusion, the following is meant to serve as general guidelines, after evaluating the patient and the clinical circumstances.

Platelets may be transfused ‘prophylactically’ (eg, in the absence of active bleeding) in the following circumstances:
Platelet count under 5

Platelet count under 20 in the setting of conditions associated with a high risk of bleeding (eg, history of bleeding duodenal ulcer, etc.) or in children undergoing a lumbar puncture

Guidelines for the use of platelet transfusions. British Journal of Hematology, 2003, 122, 10-23 and at http://www.bcshguidelines.com/

INDICATIONS FOR PLATELET TRANSFUSION
1. Platelet count under 10,000/µl due to bone marrow infiltration or suppression, for prophylaxis or bleeding.
Patients with platelet counts above 5,000/µL who are not bleeding and who are otherwise stable may not require transfusion. Between 10,000/µL and 20,000/µL, clinical judgement must be exercised with consideration to the risk of serious bleeding and to the presence of infection, coagulopathy, splenomegaly or other clinical circumstances which increase that risk by compromising platelet function or survival.

Platelet Count Threshold for Prophylactic Platelet Transfusion: Acute Leukemia Guideline: The Panel recommends a threshold of 10,000/µL for prophylactic platelet transfusion in adult patients receiving therapy for acute leukemia, on the basis of the results of multiple randomized trials that demonstrate that this approach is equivalent to the use of a 20,000/µL threshold. Transfusion at higher levels may be necessary in newborns or in patients with signs of hemorrhage, high fever, hyperleukocytosis, rapid fall of platelet count, or coagulation abnormalities (for example, acute promyelocytic leukemia) and in those undergoing invasive procedures or in circumstances in which platelet transfusions may not be readily available in case of emergencies. The studies that form the basis of this recommendation (as well as the other recommendations in this section) have included adolescents but not younger children or infants. Nevertheless, it is probably reasonable to use similar guidelines for children and older infants. Although modern automated cell counters are quite accurate at low platelet counts, there can be modest variations in count because of limitations of the counting technology. The decision to transfuse at a precise trigger level should therefore consider the clinical context and the pattern of recent platelet counts.

GUIDELINES FOR PLATELET TRANSFUSIONS
Platelet transfusions should not be given simply in response to a given blood platelet count. The underlying mechanism causing thrombocytopenia and the clinical risks of thrombocytopenia must be considered.
No Further Justification for PLATELET Transfusions is Required if One or More of the Following can be found in the medical record: [...]
2. Blood platelet count under 10,000/µl and no evidence of significant bleeding PLUS bone marrow failure by a diagnosis of progenitor cell transplant, or cancer such as leukemia, lymphoma, carcinoma, sarcoma, or precancerous state or evidence of severe bone marrow hypoplasia as by the diagnosis of aplastic/hypoplastic anemia or myelodysplastic syndrome. Transfusion at a blood platelet count of 10,000 to 20,000/ul in this "prophylactic" setting is justified only by factors that increase the risk of bleeding (e.g. active infection, liver disease with abnormal clotting study results, renal failure).

ACUTE LEUKEMIAS: Most experience during the last 10 years was gathered in patients with acute leukemias (acute promyelocytic leukemia without remission excluded). More than 1,000 patients within five published studies were safely transfused using a platelet transfusion trigger of 10,000/µl or even lower. Three of these studies prospectively compared the 10,000/µl with the traditional 20,000/µl trigger for prophylactic platelet transfusion without showing an increased risk for bleeding. The stringent trigger was used when patients did not show signs of major bleeding, fever above 38°C, plasma coagulation factor deficiencies due to sepsis or leukemia, and were without hyperleukocytosis above 50,000/µl at the start of chemotherapy. Major bleeding was defined as soft tissue bleedings requiring blood transfusion, melena, hematemesis, macrohematuria, hemoptysis, vaginal bleeding, epistaxis for more than 1 hour with gross blood loss, or retinal hemorrhages with impairment of vision. In such situations platelet transfusions should be given to maintain the platelet count above 15,000/µl or 20,000/µl. The same trigger was used when biopsies (bone marrow biopsies excluded) were to be performed.

During the last few years there still has been some concern regarding the safety of such a stringent trigger for prophylactic platelet transfusion because the number of patients in those three prospective studies was still relatively small (230 patients with the 10,000/µl trigger). We therefore prospectively examined this transfusion strategy within the German Cooperative AML-Study Group during the last 4 years in 734 patients. Our recent analysis confirms the safety and cost effectiveness of this strategy. Clinically relevant bleeding did not occur more often than as expected with the traditional trigger. No single fatal bleeding complication was due mainly to the restrictive platelet transfusion policy. About 50% of fatal bleeding events happened in patients refractory to platelet transfusion, not recovering from thrombocytopenia and in parallel with uncontrolled leukemia or severe infectious complications. Most bleeding episodes occurred during induction chemotherapy when leukemia was not yet in remission. There was absolutely no increased bleeding risk for patients above the age of 60 years.

That concludes the Page's medical research for the morning. In the hopes of having brought some relief to the Court of Chicora, to its Countess, and her Lady-in-Waiting with this rather dry but substantial chunk of information, the Page wishes all at Court a pleasant morning and a cheerful doctor's visit. Other modern means of communication will provide us contact again later in the day. Here a picture from a morning like this one in Berlin at Schloß Charlottenburg - the type of day the Countess should enjoy, watching the birds eating from a birdfeeder in spring.