AMT CMLA common mistakes
AMT CMLA · Understand the traps and how to avoid them.
Reciting the order of draw as a color list (e.g., "light blue, red, gold, green, lavender, gray") without linking each tube to its additive, mechanism, and the tests it serves, so scenario questions that describe the additive or test instead of naming the color are answered incorrectly.
Most study time goes into memorizing a color sequence from a poster or mnemonic rather than building additive-to-test reasoning, so the knowledge collapses when the exam withholds the color or presents a capillary/discard or blood-culture-first variation.
What to do instead
Rebuild the order of draw as a four-column table: tube/additive, what the additive does, tests it supports, and position in draw order. Then drill 20 matching items written so the tube is described by additive ("sodium citrate tube") or by test ("PT/INR") rather than by color, and re-derive the full sequence from the table without looking.
Leaving the tourniquet in place longer than one minute or having the patient repeatedly clench the fist during the draw, and then accepting the resulting specimen without noting it.
Candidates concentrate on hitting the vein and forget the timed steps; tourniquet and fist-pumping effects are covered in a single lecture and are not connected to abnormal results in practice.
What to do instead
Memorize the mechanism chain: stasis causes hemoconcentration, which falsely elevates potassium, total protein, and cell counts and alters enzyme results. Practice releasing the tourniquet as soon as blood flows, and rehearse the answer to "what do you do if the draw takes longer than a minute?" (release tourniquet, allow 1–2 minutes, recollect if the test is stasis-sensitive, and document).
Selecting the venipuncture site and needle gauge without screening for exclusions - drawing from the arm with a hemodialysis fistula or on the side of a mastectomy, drawing distal to or above a running IV line, or choosing a large-bore needle for a small, fragile vein.
Candidates learn site selection and needle selection as separate topics and do not practice applying the contraindication list to a described patient, so the exclusion cue in the stem goes unrecognized.
What to do instead
Write a one-page site/needle decision checklist and apply it verbally to five patient vignettes: fistula, mastectomy, IV infusion, edema, anticoagulated patient, fragile elderly vein (butterfly with smaller gauge). For IV lines, state the rule explicitly: draw below the infusion site or from the opposite arm, and note the infusion on the requisition.
Judging specimen acceptability by appearance alone - accepting a short-draw sodium citrate tube, a hemolyzed serum tube for a potassium, or a tube with a missing or mismatched label - instead of applying the written rejection criteria.
Candidates fear inconveniencing the patient or the floor and default to "run it anyway," and they underestimate how many exam items test the decision to reject and recollect.
What to do instead
Memorize the rejection list as a checklist: unlabeled or mislabeled, wrong tube for the test, insufficient volume for the additive-to-blood ratio (citrate requires the tube to be filled to the marked volume, 9:1), gross hemolysis for hemolysis-sensitive analytes, clotted anticoagulated specimens, and expired tubes. Practice writing the recollect justification each time, because the exam asks why a specimen must be rejected.
Handling separated specimens incorrectly - spinning a serum separator tube before it has fully clotted, recentrifuging a gel tube after the barrier has formed, leaving serum on cells for hours before testing glucose or potassium, or exposing bilirubin and other light-sensitive analytes to light.
Processing steps are learned as a physical routine rather than as a timed sequence with an analyte-specific rationale, so exceptions (light protection, chilling, prompt separation) are forgotten under exam pressure.
What to do instead
Make a short processing matrix: analyte or tube, required clotting time, centrifugation speed and time, whether the gel barrier permits one spin only, storage temperature, and light or ice requirements. Then answer questions that give a delay scenario ("the centrifuge was down for two hours") and predict which results will shift and in which direction.
Treating "waived" as "no quality control" - running patient point-of-care samples without the required external liquid control materials, ignoring an out-of-range control, using expired reagents or strips, or failing to record QC, lot numbers, and operator identity.
The word waived is misread as exempt from oversight, when waived testing is actually the most QC-documentation-heavy area of the exam because the operator is often the only check in the system.
What to do instead
Learn the rule as a sentence: waived testing still requires following the manufacturer's instructions, performing and documenting QC at the stated frequency, checking expiration dates, and maintaining competency records. Drill the corrective action sequence for a failed control: do not test patients, repeat with fresh control, check storage and expiration, open a new lot, and escalate if it fails again.
Performing a capillary point-of-care glucose test with technique errors - using alcohol that has not air-dried, milking or squeezing the finger, sampling a cold or cyanotic fingertip, or failing to wipe away the first drop when the device requires it.
The step-by-step method is rehearsed once in a skills lab and the rationale for each step (no residual alcohol, no tissue fluid dilution, warm well-perfused site, no smearing) is never connected to the falsely low or high result it prevents.
What to do instead
Rehearse the procedure out loud in a fixed order with the reason attached to each step: identify patient, verify strip lot and expiration, warm and position the site, cleanse and let dry completely, puncture the side of the fingertip, wipe the first drop if required, apply without milking, then record result, time, and operator. Practice interpreting a result that conflicts with the patient's symptoms and stating the confirmatory step.
Improvised spill and disinfection response - wiping a blood spill with an incorrect bleach dilution or an alcohol wipe, skipping the absorbent and decontamination sequence, or removing gloves before the outer gown and face protection when doffing PPE.
Candidates memorize "use bleach" without the concentration, contact time, or order of operations, and PPE doffing is learned as a visual sequence that is easily reversed when described in text.
What to do instead
Fix the numbers and the order: for blood or body fluid spills use a freshly prepared 1:10 dilution of household bleach (approximately 5,000 ppm available chlorine) or an approved tuberculocidal disinfectant, applied after removing visible material with absorbent material, allowing the manufacturer's contact time. Practice the doffing order in writing: gloves, then face protection, then gown, then perform hand hygiene.
Labeling tubes before the draw or relying on a room number, chart, or verbal statement instead of two independent identifiers confirmed at the bedside, and accepting a pre-labeled tube from another staff member.
Pre-labeling saves time on a busy round and is common informal practice, so it feels correct; candidates also confuse a room or bed number with an acceptable identifier.
What to do instead
Internalize the rule as: identify the patient by two identifiers (full name plus date of birth or another facility-approved identifier), compare them to the requisition, and label the tubes at the bedside immediately after collection in the patient's presence. Practice refusal language: state politely that you must confirm the name and date of birth and label at the bedside, and that pre-labeled tubes cannot be accepted.
Answering patient questions about results or diagnosis, or discussing one patient's information where another patient or a family member can hear, instead of deflecting to the appropriate provider and protecting confidentiality.
Candidates want to be helpful and reassuring and misjudge the boundary between reassurance and interpretation, and confidentiality is studied as an abstract principle rather than as a set of concrete conversational situations.
What to do instead
Prepare and practice three short scripts: one for "what did my results show?" (explain that the provider will review results with them), one for a family member asking for information (verify the patient's permission or refer to the provider or release-of-information process), and one for discussing a case in a hallway or elevator (defer to a private area with no identifiers). Pair each script with the underlying principle so the exam rationale makes sense.