Injection routes, sites and angles

Three routes, three angles, three needle specifications — and the CCMA builds most of its items by giving you one of the nine and asking for another. The reliable way through is to memorize each route as a complete package rather than as an angle on its own.

Questions and answers, explained

All 12 questions above, with the correct answer and why it is correct. Everything here is on injection routes, sites and angles.

1. A medical assistant is transcribing a verbal order and hears "insulin glargine ten units subcutaneously at bedtime." Which documentation is correct and compliant?

   • A"Insulin glargine 10U subq at HS, per verbal order"
   • B"Insulin glargine 10.0 u SQ qhs, verbal order read back"
   • C"Insulin glargine 10 IU SC nightly, per telephone order"
   • D"Insulin glargine 10 units subcutaneously at bedtime"Correct

   Why: "Units" must be spelled out; U and IU are on The Joint Commission "Do Not Use" list because U can be misread as a zero, a four, or "cc," turning 10 units into 100 units. Option B is the most dangerous distractor because it combines the prohibited "u" with a prohibited trailing zero (10.0).

   Reference Domain 1B, k10; The Joint Commission Do Not Use list (U, IU, trailing zero)

2. A competent adult states clearly that he does not want the tuberculin skin test. The medical assistant tells him it is required for his job paperwork and injects him anyway. The injection itself is best classified as:

   • AAssault, because he was misled about the test being required
   • BNegligence, because the standard of care was not followed
   • CInvasion of privacy, because his refusal was disregarded
   • DBattery, because he was touched without giving consentCorrect

   Why: Battery is intentional harmful or offensive contact with another person without consent, and injecting a patient who has refused meets that definition; a competent adult's right to refuse any treatment is part of the Patient's Bill of Rights. Assault is a different tort: it is conduct that puts someone in reasonable apprehension of imminent harmful contact and requires no touching at all. Misstating that the test was a job requirement is a misrepresentation, not an apprehension of contact, so option A names the wrong tort for the wrong reason, and once the needle enters the skin the completed tort is battery. Negligence would require a breach of the standard of care that caused harm, not an intentional act. The correct response is to document the refusal and notify the provider.

   Reference Domain 7, k221 (criminal and civil acts; medical malpractice), k215 (Patient's Bill of Rights); NIH/StatPearls, assault and battery in health care; Restatement (Second) of Torts secs. 13, 21

3. A medical assistant must give influenza vaccine from a multi-dose vial to two patients scheduled back to back. Which action follows CDC safe injection practices?

   • AUse the same syringe for both patients as long as a new needle is attached
   • BLeave a needle inserted in the vial septum so doses can be drawn quickly
   • CDraw both doses into one syringe and divide them at the point of care
   • DUse a new sterile needle and a new sterile syringe for every entry into the vial and for every patientCorrect

   Why: CDC safe injection practices, part of standard precautions, require a new sterile needle AND a new sterile syringe for each patient and for each entry into a medication vial; the syringe is considered contaminated once used. Choice A is a documented cause of hepatitis B and C outbreaks in outpatient clinics, because backflow contaminates the syringe barrel even when only the needle is changed.

   Reference Domain 3C (k100); CDC safe injection practices / One and Only Campaign

4. Three patients are waiting for injections in a busy clinic. When should the medical assistant document each injection in the electronic health record (EHR)?

   • AImmediately after the medication is administeredCorrect
   • BBefore entering the room, so the chart is already updated
   • CAt the end of the shift, entering all of the injections together
   • DOnly if the patient reports an adverse effect

   Why: Right documentation means charting immediately after the dose is given, by the person who gave it. Charting in advance (B) creates a false legal record if the dose is never given or the patient refuses, and batching entries at the end of the shift (C) invites omissions and wrong-patient errors.

   Reference Domain 3B, task 3B17 document relevant aspects of patient care; k22 right documentation

5. Which needle gauge is most commonly used for routine adult venipuncture with an evacuated tube system?

   • A16 gauge
   • B18 gauge
   • C21 gaugeCorrect
   • D25 gauge

   Why: Routine adult venipuncture with an evacuated tube system uses a 20 to 22 gauge needle, and 21 gauge is the standard multisample needle for an adult antecubital draw; 23 gauge is reserved for winged sets and small or fragile veins. Remember that the larger the gauge number, the smaller the lumen. A 16 or 18 gauge needle is used for blood donation or infusion, not routine specimens, and a 25 gauge lumen is small enough to shear red cells and hemolyze the sample.

   Reference Domain 3E; k133-k134 insertion technique and equipment; evacuated tube needle gauge 20-22 for routine adult venipuncture (21 most common)

6. Percutaneous prick/puncture allergy skin tests, listed as scratch tests in the NHA outline, are applied to a patient's back. When are they read, and what is measured?

   • AAt 5 minutes; the amount of bleeding at each scratch site
   • BAt 15 to 20 minutes; the wheal and flare at each siteCorrect
   • CAt 48 to 72 hours; the induration across the test area
   • DAt 24 hours; the redness that remains at each site

   Why: The percutaneous method in current use is the prick/puncture test, in which a lancet pricks the epidermis through a drop of extract; the older scratch technique, which abrades a line in the skin, has largely been abandoned for poor reproducibility, although the NHA outline still uses the word scratch. Percutaneous and intradermal allergy tests detect immediate, IgE-mediated hypersensitivity, so the reaction develops within minutes and is read at about 15 to 20 minutes. The medical assistant measures the wheal, the raised pale area, and the surrounding flare of redness in millimeters, and compares every site with the histamine positive control and the saline or glycerin negative control placed with the panel; without those controls the results cannot be judged. Reading at 48 to 72 hours and measuring induration (C) is the Mantoux tuberculin skin test, a delayed reaction, and it is the most common mix-up on this topic. The patient must stay in the office for the entire observation period, and epinephrine and emergency equipment must be immediately available, because systemic reactions are rare but possible. The provider interprets which allergens are positive.

   Reference Domain 3D; 3D7 perform allergy testing; k120 scratch test and intradermal allergy test; AAAAI common office procedures (prick/puncture is the percutaneous method in current use, read at 15-20 minutes with histamine positive and saline/glycerin negative controls); Mantoux tuberculin test read at 48-72 hours for induration

7. A provider orders "ceftriaxone 500 mg IM now." The medical assistant verifies the patient's name and date of birth, confirms the drug and its expiration date, measures the 500 mg dose, and confirms the intramuscular route, then administers it immediately as ordered. Which of the six rights has NOT yet been addressed?

   • ARight patient — name and date of birth verified
   • BRight drug — the vial label was checked
   • CRight dose — 500 mg was measured out
   • DRight documentation — the record entryCorrect

   Why: The six rights are right patient, right drug, right dose, right route, right time, and right documentation; charting the administration immediately after — never before — the medication is given completes the process. Right dose, the closest distractor, was already satisfied when the MA measured the ordered 500 mg.

   Reference Domain 1C, k22 (rights of medication administration)

8. A medical assistant has drawn up a medication and must carry the syringe a short distance across the room before injecting. What does OSHA require?

   • ARecap the needle using both hands to hold the cap steady while pushing it on
   • BDo not recap by hand; if unavoidable, use a device or one-handed scoopCorrect
   • CBend the needle slightly so that it cannot stick anyone
   • DRemove the needle from the syringe and carry them separately

   Why: 29 CFR 1910.1030 states that contaminated needles shall not be bent, recapped, or removed unless no alternative is feasible or the action is medically required, and then only with a mechanical device or a one-handed technique. Choice A is the single most common cause of self-inflicted needlesticks, because the hand holding the cap is directly in the path of the needle.

   Reference Domain 3C (k97, k108); OSHA 29 CFR 1910.1030(d)(2)(vii)

9. The provider orders cefdinir 250 mg PO. The oral suspension on hand is labeled 125 mg/5 mL. How many milliliters should the medical assistant prepare?

   • A2.5 mL
   • B5 mL
   • C10 mLCorrect
   • D12.5 mL

   Why: Using desired over have times quantity: 250 mg divided by 125 mg equals 2, multiplied by 5 mL equals 10 mL. Answer B (5 mL) is the volume that would deliver only 125 mg, half the ordered dose.

   Reference Domain 3B; k68 dosage calculations related to injectables and oral medications (D/H x Q)

10. A patient has small, fragile veins and the only acceptable site is a dorsal hand vein. Which equipment choice is most appropriate?

    • AA 21 gauge multisample needle with a standard evacuated tube holder
    • BA 23 gauge winged (butterfly) set with small-volume tubesCorrect
    • CAn 18 gauge needle attached to a 20 mL syringe
    • DA 25 gauge needle attached directly to an evacuated tube holder

    Why: A 23 gauge winged infusion set with flexible tubing lets the medical assistant enter at a shallow angle and control the draw, and small-volume tubes limit the vacuum pull that collapses fragile veins. Winged sets used for blood collection run 21 to 23 gauge, and 23 gauge is the smallest lumen appropriate for drawing specimens. A large-bore needle with a 20 mL syringe (C) generates far too much suction for a hand vein, and a 25 gauge lumen (D) forces cells through too narrow an opening and causes hemolysis.

    Reference Domain 3E; k134 evacuated tube, syringe, and butterfly methods; winged (butterfly) sets for blood collection are 21-23 gauge

11. A multidose vial of an injectable medication is labeled "Store at 2°C to 8°C. Protect from light." Where should the medical assistant store it?

    • AOn the medication room counter, well away from any of the windows and heat vents
    • BIn the freezer compartment of the clinic refrigerator
    • CIn the clinic refrigerator, in its original carton, with the temperature loggedCorrect
    • DIn a locked cabinet at controlled room temperature

    Why: The labeled range of 2°C to 8°C (36°F to 46°F) is standard refrigeration; the original carton provides the required light protection, and a temperature log documents that the cold chain was maintained. Freezing, the closest distractor, falls outside the labeled range and can irreversibly destroy the product even if it is later thawed.

    Reference Domain 1C, k23, k71, k74 (storage, labeling, logs); FDA-approved product labeling; CDC Vaccine Storage and Handling Toolkit

12. After an injection and a dressing change, a medical assistant has three items: a used needle with the safety device activated, a 4x4 gauze with a small dried blood spot that would not release fluid if compressed, and a gauze saturated with blood that drips. How should these be discarded under OSHA's definition of regulated waste?

    • AAll three items go into the red biohazard bag together
    • BAll three items go into the regular trash receptacle
    • CThe needle in the sharps container, both gauze pads in the regular trash
    • DNeedle in sharps, saturated gauze in the red bag, spotted gauze in trashCorrect

    Why: OSHA defines regulated waste as liquid or semi-liquid blood, items that would release blood in a liquid or semi-liquid state if compressed, items caked with dried blood capable of releasing it during handling, contaminated sharps, and pathological or microbiological wastes. Choice A over-classifies: routing lightly soiled dressings to regulated waste is a common practice error that greatly increases disposal cost without adding protection, though the medical assistant should always follow any stricter state or local rule.

    Reference Domain 3C (k108); OSHA 29 CFR 1910.1030(b) definition of regulated waste

Drill the whole domain

• General Patient Care (18.7%)
• Foundational Knowledge and Basic Science (10%)
• Infection Control and Safety (10%)

Other topics

• Autoclave testing: spore tests and sterilizer monitoring
• Correcting an error in the medical record
• HIPAA disclosures and minimum necessary
• Informed vs implied consent, and who obtains it
• Medical vs surgical asepsis and Spaulding
• Order of draw and tube additives
• OSHA Bloodborne Pathogens Standard duties
• PPE donning and doffing: the CDC order
• Medical assistant scope of practice
• Sharps, regulated waste and the red bag
• Standard vs transmission-based precautions
• Vital sign normal ranges and technique errors
• Blood pressure categories and measurement errors
• Venipuncture vein selection and what to avoid
• Vaccine cold chain and storage
• Specimen labeling and patient identification

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