Emergent Large-Bore Central Venous Catheter Placement in Severely Thrombocytopenic Patients with Suspected Immune-Mediated Thrombotic Thrombocytopenic Purpura Is Safe and Effective

Introduction: Immune-mediated thrombotic thrombocytopenic purpura (iTTP) is a progressive and nearly uniformly fatal disease if not suspected and managed with plasma exchange (PLEX). Initiation of PLEX requires placement of a large-bore central venous catheter (CVC) in a patient with severe thrombocytopenia where platelet transfusion is contraindicated except in the setting of life-threatening hemorrhage. We sought to determine the safety and complication rates of large-bore CVC placement in patients with suspected iTTP.

Methods: The Parkland Health and Hospital System electronic medical record system was queried for ADAMTS13 labs from 7/2011 to 7/2021, identifying 1,371 ordered tests with 465 being ordered in the emergency department, observation, or inpatient setting. Sixty-eight patients had a large-bore CVC placed for PLEX with suspicion for iTTP. Characteristics of providers performing CVC placement were obtained via chart review. Records were reviewed for complications, including death, infection, thrombosis, bleeding, pneumothorax, or pressure ulcers. Minor bleeding complications were procedure site hematomas and self-limited episodes of bleeding requiring manual pressure. The only major complication was a hematoma that required intubation for airway protection. Categorical variables were compared using the chi-square test, while continuous variables were compared using the Wilcox rank sum test.

Results: Of the 68 patients, the majority were Black or Hispanic (84%). Central venous catheter placement was most often performed by General Surgery (68%) followed by the Medical Intensive Care Unit (MICU; 12%), Emergency Medicine (7%), and Nephrology (7%). Surgery and Emergency Medicine placed significantly more catheters in patients who ultimately had iTTP (P = 0.03). Resident physicians placed the majority of CVCs (79%) with no prophylactic blood products used in over 90% of cases. There was a 12% (8 out of 68) complication rate predominantly related to bleeding (n=7), although one patient had a pressure ulcer due to a lack of mobility after a femoral vein CVC placement. There was only one severe complication with the development of a rapidly expanding hematoma during an internal jugular (IJ) line placement causing airway compromise and requiring intubation. There were no differences in complication rates between line placement by General Surgery versus other services (P = 0.91) or with prophylactic platelet (P = 0.81), cryoprecipitate (P = 0.59), or FFP (P = 0.70) transfusions. A significant association was observed between the number of line attempts (median [IQR]) and complications (2 [2-4] v patients without complications: 1 [1-1], P < 0.001). In patients with iTTP, pre-procedural coagulation parameters had significantly lower platelets, lower INR, lower PT, and higher fibrinogen, suggesting a level of coagulopathy and/or disseminated intravascular coagulation in patients who were ultimately not found to have iTTP.

Discussion: In a tertiary hospital, there was only one severe complication of large-bore CVC placement was observed in a cohort of 68 patients-most of whom had severe thrombocytopenia and did not receive prophylactic platelet or cryoprecipitate transfusions. Furthermore, resident physicians placed 79% of these CVCs without a significant increase in complication rate. Given that iTTP is a severe and progressive disease requiring emergent intervention, our findings suggest that CVC insertion for PLEX should not be delayed due to concerns regarding thrombocytopenia or bleeding complications. Most complications were minor bleeding or hematomas that resolved with pressure and observation. No significant difference in the rate of complications was observed when comparing surgical and non-surgical services. Conversely, there was an association between the number of CVC placement attempts and complications, suggesting that the line should be placed by whomever is qualified and available to expedite treatment.

No relevant conflicts of interest to declare.