Low titer A plasma in three AB patients for therapeutic plasma exchange

Benchmarking the centralized urgent plasma exchange service for patients admitted with a diagnosis of suspected acquired thrombotic thrombocytopenic purpura at a large healthcare system

BACKGROUND

Consensus guidelines recommend that therapeutic plasma exchange (TPE) should be started within 4 to 8 hours after the diagnosis of suspected acquired thrombotic thrombocytopenic purpura (aTTP). This study aimed to audit the steps from diagnosis to initiation of plasma exchange at a centralized apheresis service.

METHODS

A retrospective review of the electronic medical record and laboratory information systems from January 1, 2014 to August 31, 2017 was conducted to identify all patients with suspected aTTP undergoing TPE. Demographics, comorbidities, pertinent laboratory tests, and temporal TPE procedural data were collected.

RESULTS

The median (5th-95th percentile) time from request to initiation of TPE was 5.4 (3.2-10.6) hours. TPE was initiated within 8 hours in 94 of the 108 patients (87.0%). The median (5th-95th percentile) time from request to central venous access was 2.5 (0.5-6.9) hours and from request to plasma product issuance from the blood bank was 3.4 (1.6-8.1) hours. aTTP patients in whom TPE was initiated greater than 6 hours from request did not have worse outcomes compared to those with TPE initiation within 6 hours: in-hospital mortality (2/14 [14.3%] vs 2/21 [9.5%], P = 0.66), median length of stay (9.0 [4.7-44.1] vs 8.3 [3.9-27.0] days, P = 0.76), and median number of days to durable platelet count recovery (4.5 [2.0-9.0] vs 4.0 [2.0-18.0] days, P = 0.66).

CONCLUSIONS

The 4 to 8-hour target window from TPE request to initiation appears feasible for a centralized apheresis program servicing a large healthcare system.