Thrombocytopenia and platelet transfusions in patients with cancer

Therapeutic Challenges in the Management of Acute Pulmonary Embolism in a Cancer Patient with Chemotherapy-induced Thrombocytopenia

This case demonstrates the therapeutic challenges encountered when managing an acute pulmonary embolism in a cancer patient with thrombocytopenia. A 64-year-old man with a history of lung cancer receiving chemotherapy was admitted to Walsall Manor Hospital with haemodynamic instability consistent with a pulmonary embolism, proven on computed tomographic pulmonary angiogram. His platelet count was noted to be 35×10⁹/l (chemotherapy-induced thrombocytopenia). After discussions, he was deemed not suitable for thrombolysis based on risk versus benefits. The patient was initially transfused one adult dose of platelets and treated with half the therapeutic dose of low molecular weight heparin (LMWH). The same management plan was followed until the platelet count exceeded 50×10⁹/l, after which the patient was established on the full therapeutic dose of LMWH. Clinically, the patient improved and was discharged. Three months after discharge, follow-up revealed sustained clinical improvement while the patient continued to be on the full therapeutic dose of LMWH with a stable platelet count.

Use of platelet transfusions prior to lumbar punctures or epidural anaesthesia for the prevention of complications in people with thrombocytopenia

BACKGROUND

People with a low platelet count (thrombocytopenia) often require lumbar punctures or an epidural anaesthetic. Lumbar punctures can be diagnostic (haematological malignancies, subarachnoid haematoma, meningitis) or therapeutic (spinal anaesthetic, administration of chemotherapy). Epidural catheters are placed for administration of epidural anaesthetic. Current practice in many countries is to correct thrombocytopenia with platelet transfusions prior to lumbar punctures and epidural anaesthesia, in order to mitigate the risk of serious procedure-related bleeding. However, the platelet count threshold recommended prior to these procedures varies significantly from country to country. This indicates significant uncertainty among clinicians regarding the correct management of these patients. The risk of bleeding appears to be low, but if bleeding occurs it can be very serious (spinal haematoma). Consequently, people may be exposed to the risks of a platelet transfusion without any obvious clinical benefit.This is an update of a Cochrane Review first published in 2016.

OBJECTIVES

To assess the effects of different platelet transfusion thresholds prior to a lumbar puncture or epidural anaesthesia in people with thrombocytopenia (low platelet count).

SEARCH METHODS

We searched for randomised controlled trials (RCTs), non-randomised controlled trials (nRCTs), controlled before-after studies (CBAs), interrupted time series studies (ITSs), and cohort studies in CENTRAL (the Cochrane Library 2018, Issue 1), MEDLINE (from 1946), Embase (from 1974), the Transfusion Evidence Library (from 1950), and ongoing trial databases to 13 February 2018.

SELECTION CRITERIA

We included RCTs, nRCTs, CBAs, ITSs, and cohort studies involving transfusions of platelet concentrates, prepared either from individual units of whole blood or by apheresis, and given to prevent bleeding in people of any age with thrombocytopenia requiring insertion of a lumbar puncture needle or epidural catheter.The original review only included RCTs.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane for including RCTs, nRCTs, CBAs, and ITSs. Two review authors independently assessed studies for eligibility and risk of bias and extracted data. Results were only expressed narratively.

MAIN RESULTS

We identified no completed or ongoing RCTs, nRCTs, CBAs, or ITSs. No studies included people undergoing an epidural procedure. No studies compared different platelet count thresholds prior to a procedure.In this update we identified three retrospective cohort studies that contained participants who did and did not receive platelet transfusions prior to lumbar puncture procedures. All three studies were carried out in people with cancer, most of whom had a haematological malignancy. Two studies were in children, and one was in adults.The number of participants receiving platelet transfusions prior to the lumbar puncture procedures was not reported in one study. We therefore only summarised in a narrative form the relevant outcomes from two studies (150 participants; 129 children and 21 adults), in which the number of participants who received the transfusion was given.We judged the overall risk of bias for all reported outcomes for both studies as 'serious' based on the ROBINS-I tool.No procedure-related major bleeding occurred in the two studies that reported this outcome (2 studies, 150 participants, no cases, very low-quality evidence).There was no evidence of a difference in the risk of minor bleeding (traumatic tap) in participants who received platelet transfusions before a lumbar puncture and those who did not receive a platelet transfusion before the procedure (2 studies, 150 participants, very low-quality evidence). One of the 14 adults who received a platelet transfusion experienced minor bleeding (traumatic tap; defined as at least 500 x 10⁶/L red blood cells in the cerebrospinal fluid); none of the seven adults who did not receive a platelet transfusion experienced this event. Ten children experienced minor bleeding (traumatic taps; defined as at least 100 x 10⁶/L red blood cells in the cerebrospinal fluid), six out of the 57 children who received a platelet transfusion and four out of the 72 children who did not receive a platelet transfusion.No serious adverse events occurred in the one study that reported this outcome (1 study, 21 participants, very low-quality evidence).We found no studies that evaluated all-cause mortality within 30 days from the lumbar puncture procedure, length of hospital stay, proportion of participants who received platelet transfusions, or quality of life.

AUTHORS' CONCLUSIONS

We found no evidence from RCTs or non-randomised studies on which to base an assessment of the correct platelet transfusion threshold prior to insertion of a lumbar puncture needle or epidural catheter. There are no ongoing registered RCTs assessing the effects of different platelet transfusion thresholds prior to the insertion of a lumbar puncture or epidural anaesthesia in people with thrombocytopenia. Any future study would need to be very large to detect a difference in the risk of bleeding. A study would need to be designed with at least 47,030 participants to be able to detect an increase in the number of people who had major procedure-related bleeding from 1 in 1000 to 2 in 1000. The use of a central data collection register or routinely collected electronic records (big data) is likely to be the only method to systematically gather data relevant to this population.

Value in palliative cancer surgery: A critical assessment

Emergency operations are associated with increased morbidity, mortality, and cost compared to elective operations. Palliative and emergent surgery for patients with advanced malignancies is associated with additional risk and remains controversial. Emergent or palliative interventions can be broadly categorized according to indication. Tumor related complications (bleeding, obstruction, or perforation) merit specific consideration, as do specific presentations such as pneumoperitoneum, pneumatosis intestinalis, or peritonitis from other causes that may arise during active therapy for malignancies. Although nonoperative, endoscopic, and interventional treatment modalities are frequently available, surgery remains the only effective therapy in selected situations such as small intestinal obstruction and tumor perforation. Selection of patients for surgery requires consideration of factors including overall prognosis, performance status, and patients' priorities. Selection and risk assessment tools underscore the limited capacity of patients' with higher risk features for durable recovery but do not supplant nuanced clinical judgment. J. Surg. Oncol. 2016;114:311-315. © 2016 Wiley Periodicals, Inc.

Blood Loss and Massive Transfusion in Patients Undergoing Major Oncological Surgery: What Do We Know?

Patients with solid malignancies who were not candidates for tumor resections in the past are now presenting for extensive oncological resections. Cancer patients are at risk for thromboembolic complications due to an underlying hypercoagulable state; however, some patients may have an increased risk for bleeding due to the effects of chemotherapy, the administration of anticoagulant drugs, tumor-related fibrinolysis, tumor location, tumor vascularity, and extent of disease. A common potential complication of all complex oncological surgeries is massive intra- and postoperative hemorrhage and the subsequent risk for massive blood transfusion. This can be anticipated or unexpected. Several surgical and anesthesia interventions including preoperative tumor embolization, major vessel occlusion, hemodynamic manipulation, and perioperative antifibrinolytic therapy have been used to prevent or control blood loss with varying success. The exact incidence of massive blood transfusion in oncological surgery is largely unknown and/or underreported. The current literature mostly consists of purely descriptive observational studies. Thus, recommendation regarding specific perioperative intervention cannot be made at this point, and more research is warranted.