CI-CPT cheat sheet

Order of draw for venous tubes: blood culture (or sterile) tubes first, then light-blue sodium citrate, serum (red/gold), heparin (green), EDTA (lavender), and glycolytic inhibitor (gray) tubes last; fill additive tubes to the stated volume to keep additive-to-blood ratios correct.

Sodium citrate tubes must be filled to at least 90% of nominal draw volume; underfilling raises citrate concentration and falsely prolongs PT and aPTT.

Tourniquet application should not exceed 1 minute; prolonged stasis causes hemoconcentration, raises potassium, protein, and cell counts, and promotes hemolysis.

Preferred venipuncture sites are the median cubital, cephalic, and basilic veins of the antecubital fossa; the basilic vein lies near the brachial artery and median nerve, so it carries higher risk.

Needle gauge and blood flow: 21-22 gauge is standard for adults; small gauges (23-25) increase shear and hemolysis, and a 16-18 gauge is used for blood donation or rapid large-volume draws.

Capillary puncture order: wipe away the first drop, then fill EDTA (lavender) tubes before other additive tubes, and collect serum/gel tubes before EDTA when both are needed for platelet counts.

Hemolysis falsely increases potassium, LDH, AST, and plasma hemoglobin while falsely decreasing glucose, sodium, and some enzyme activities depending on method.

Blood culture collection: 20-30 mL per set in adults, drawn before antimicrobial therapy, with aerobic and anaerobic bottles each inoculated from a separate syringe or directly per device instructions.

Serum tubes clot 30 minutes at room temperature before centrifugation; incomplete clotting produces fibrin strands that can clog analyzers or be reported as fibrin interference.

Centrifugation for routine chemistry typically uses 1,000-1,200 x g for 10-15 minutes at room temperature; gel-barrier tubes must reach the gel's density range to separate cleanly.

Serum or plasma should be separated from cells within 2 hours of collection; delayed separation raises potassium, LDH, and glucose loss from glycolysis.

Light-sensitive analytes (bilirubin, vitamin B12, folate, porphyrins) require amber tubes or foil wrapping during storage and transport.

Cold storage is not universal: cryoglobulins and cold agglutinins require 37 degrees C transport, while ammonia and lactate require immediate ice and rapid separation.

Specimen rejection criteria include unlabeled or mislabeled tubes, gross hemolysis, insufficient volume in citrate tubes, clotted anticoagulated samples, and expired collection devices.

Additive carryover: drawing an EDTA tube before a calcium or alkaline phosphatase tube on a shared line can falsely lower calcium and alkaline phosphatase; use a discard tube or proper order of draw.

Transport temperature rules: most chemistry and hematology specimens travel at 2-8 degrees C or ambient per policy, but microbiology swabs and some molecular tests require specific media and ambient conditions.

Fasting status alters glucose, triglycerides, and LDL; a typical fasting requirement is 8-12 hours of no caloric intake, with water allowed.

Patient identification requires two independent identifiers (full name and date of birth or unique ID number) verified against the requisition at the bedside, never by room or bed number.

Standard precautions apply to all patients: gloves for every venipuncture, and additional PPE (gown, mask, eye protection) when splash or spray exposure is anticipated.

Needlestick injury first aid: wash the site with soap and water, do not squeeze or scrub, then report immediately for post-exposure evaluation and prophylaxis decisions.

Syncope prevention: draw patients lying down if they have a history of fainting, and never leave a patient unattended after venipuncture until bleeding has stopped.

Tourniquet and site prep: cleanse with 70% isopropyl alcohol in concentric circles and let it air dry; do not fan or blow on the site.

Hemoconcentration risk factors include prolonged tourniquet time, excessive fist pumping, and drawing above an IV site; avoid drawing from an arm with an active IV line.

Latex allergy and anticoagulant sensitivity: document allergies, use latex-free supplies, and note that EDTA, heparin, and citrate are distinct agents requiring specific patient history.

POC glucose meters require periodic quality control, calibration verification, and correlation with central laboratory results per regulatory and accreditation standards.

Capillary glucose is measured on whole blood but meters report plasma-equivalent values; whole-blood glucose is lower than plasma glucose by roughly 10-15% at high hematocrit.

Hematocrit affects POC results: very high hematocrit lowers whole-blood glucose readings, and very low hematocrit can falsely elevate them.

POC INR devices using whole blood are affected by hematocrit and by lupus anticoagulant; discrepant results require confirmation by the central laboratory.

Blood gas and electrolyte POC analyzers require sample mixing, exclusion of air bubbles, and analysis within minutes because air exposure shifts pH, pCO2, and pO2.

POC test strips and cartridges are lot-specific; verify lot numbers, expiration dates, and storage conditions, and record the operator ID and control results.

POC testing must follow the same quality framework as the central lab: written procedure, trained and competency-assessed operators, documented QC, and result reporting to the medical record.

Delta checks and critical value reporting apply to POC results; a critical POC value must be verified and communicated per policy, not simply charted.

Patient confidentiality is governed by privacy law and institutional policy; disclose results only to authorized care team members and never in public areas.

Informed consent for phlebotomy includes explaining the procedure, risks (bruising, hematoma, fainting), and the patient's right to refuse or ask questions.

Therapeutic communication techniques include open-ended questions, reflective listening, and avoiding medical jargon; use a qualified interpreter for patients with limited language proficiency, not a family member.

Scope of practice: a phlebotomist may collect and label specimens but must not interpret results or provide clinical advice; refer clinical questions to the ordering provider.

Error disclosure and documentation: report collection errors, mislabeling, or adverse events promptly and factually, and follow the facility's incident reporting process.

Conflict and difficult interactions: remain calm, acknowledge the patient's concern, state what you can do, and escalate to a supervisor when safety or consent is in question.

Competency and continuing education: maintain current certification, complete required training, and participate in proficiency testing and quality improvement activities.

Chain of custody and legal specimens: maintain unbroken documentation, seal, and signature trail for forensic or employment-related collections, and follow jurisdiction-specific rules.