Simple change in blood draw technique could slash lab errors in ERs

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Age 18 years or older * Presenting to the emergency department and triaged as green (semi-urgent) or yellow (urgent) category according to the Emergency Severity Index (ESI) or equivalent institutional triage system * Blood collection (venipuncture) indicated as part of routine clinical care by the attending emergency physician * Ability to provide written informed consent * Accessible peripheral vein suitable for standard venipuncture, most often in the antecubital fossa but at the operator's discretion an alternative peripheral site such as the dorsum of the hand (not requiring intravenous catheter placement for blood collection) Exclusion Criteria: * Blood collection performed via an existing intravenous catheter or central venous access device * Critical illness or hemodynamic instability, including triage category red (resuscitation) at the time of blood collection * Anticoagulant or thrombolytic therapy, or any condition in which collection of a coagulation tube was contraindicated, including a known or suspected coagulation disorder (e.g., hemophilia, thrombocytopenia with platelet count \<50,000/uL) * Known hemolytic disease, a history of active hemolysis, or another hematological condition associated with baseline elevated hemolysis * Red blood cell transfusion within the preceding 24 hours * Pregnancy of any gestational age * Absence of a peripheral vein suitable for standard venipuncture * Local pathology preventing collection from the antecubital fossa: infection, hematoma, burn, active upper extremity injury, lymphedema, an arteriovenous fistula, or the side of a previous mastectomy * Only a single collection tube ordered (the intervention requires at least two tubes, because it is defined by the timing of cuff release relative to tube filling) * Inability to give informed consent, or declining to participate * Previously enrolled in this study (re-enrollment not permitted)