One of the critical values used at UTMB is a PTT greater than 70 seconds. This value is easily achieved with therapeutic concentrations of heparin, which results in many unnecessary calls. To help reduce the call volume, the Medical Staff Executive Committee has voted to change the PTT critical value at UTMB from greater than 70 seconds to greater than 100 seconds. Please contact Dr. Michael Laposata, Chair, Department of Pathology, with any questions or concerns.

Referral Testing is processed and sent out Monday – Friday 8am-1pm. Specimens received after 1 PM will be shipped the following business day (if Friday, then following Monday). As a general rule, time sensitive specimens should not be collected on a Friday or the eve of a Holiday. STAT or Time Sensitive specimens (to be picked up Saturday, Sunday, or Holiday eve), you MUST notify a Specimen Management staff member.