L 15 Core Clinical Skills & Informed Consent – Comprehensive Study Notes

Instructional Objectives

  • Mastery goals span five core clinical skill areas & informed consent.
    • Venipuncture, Peripheral IV insertion, Injections (ID, SQ, IM), Cervical specimen collection, Basic wound closure (suturing).
    • Understand indications, contraindications, equipment, step-by-step technique, numerical sizing systems (needle gauge, catheter gauge, suture size), complications, documentation, and patient-centered communication.

Venipuncture

  • Purpose
    • Diagnostic: obtain venous blood for laboratory analysis.
    • Therapeutic: polycythemia, porphyria, hemochromatosis, etc.
  • Contraindications
    • Local infection, phlebitis, vascular anomaly, existing infusion catheter near site, severe edema/burns.
  • Equipment
    • Plastic hub with hypodermic needle & vacuum tube (Vacutainer system), tourniquet, alcohol or povidone-iodine swab, gauze, gloves, biohazard sharps container.
    • Tubes contain specific anticoagulants; color coding:
    • Red – serum (chemistry, serology).
    • Light blue – citrate for coagulation studies.
    • Green – heparinized plasma.
    • Lavender – EDTA for hematology (CBC).
    • Gray – fluoride/oxalate for glucose & lactate.
  • Numerical gauge (needle): lower number → larger diameter; typical venipuncture needles are 18\text{–}22 g.
  • Technique (abridged MWU checklist)
    1. Verify patient (name, DOB); screen latex allergy.
    2. Hand hygiene & gloves.
    3. Prepare/arrange supplies before puncture.
    4. Position arm; inspect/palpate for straight, palpable vein (usually median cubital in antecubital fossa).
    5. Apply tourniquet 3\text{–}4\;\text{in} proximal; ask patient to clench fist.
    6. Cleanse site; allow to air-dry; do not repalpate after cleaning.
    7. Anchor skin distal to site; insert needle bevel-up at 15^{\circ}\text{–}30^{\circ}; once vein entered, lower angle parallel.
    8. Engage Vacutainer; allow tube to fill ≥½; avoid rotating needle.
    9. Remove tube, release tourniquet, ask patient to relax fist.
    10. Withdraw needle; immediate gauze pressure until hemostasis.
    11. Dispose sharps; document.
  • Complications
    • Pain, bruising/hematoma, vasovagal syncope, infection, arterial puncture, nerve injury.

Peripheral IV Insertion

  • Purpose
    • Continuous/bolus fluid resuscitation, medication infusion, blood products, contrast media.
  • Contraindications
    • Infection/phlebitis at site, recent trauma or surgery that impairs venous return (e.g., post-mastectomy arm), AV fistula, extremity with lymphedema or DVT.
  • Equipment
    • Non-sterile gloves, alcohol wipe, tourniquet, IV catheter (Angiocath/Autoguard), transparent dressing, tape, extension tubing or IV line, flush, sharps container.
  • Catheter Gauge System
    • Gauge reflects external diameter; lower gauge = larger bore.
    • Large bore 14,\;16,\;18 g → rapid fluid/blood in trauma.
    • Routine meds/maintenance 20\text{–}24 g.
    • Length varies; pediatrics/neonates may need shorter \le 1\;\text{in}.
  • Basic Technique
    1. Tourniquet, vein selection, skin prep.
    2. Enter vein until flash chamber fills.
    3. Advance catheter slightly to seat tip; slide plastic catheter off needle into vein.
    4. Apply digital pressure proximal, retract needle (autoshield), release tourniquet.
    5. Connect tubing/flush; secure with dressing.
  • Maintenance principle: replace peripheral catheter every 3\text{–}4 days to minimize infection.
  • Complications
    • Pain, bleeding, localized hematoma, phlebitis, thrombosis/embolism, infiltration/extravasation, infection, nerve damage.

Injections (ID, SQ, IM)

  • Indications
    • Medication or vaccine delivery when oral/IV route inappropriate or when depot effect desired.
  • General Contraindication
    • Local skin infection or dermatitis at intended site.
  • “Five-Rights” Confirmation
    • Right patient, drug, dose, route, site, time (MWU: Confirm → Clean → Use → Inject mnemonic).
  • Needle angle & site
    • Intramuscular (IM): 90^{\circ} to skin; deltoid (≥3 y), vastus lateralis (infants), ventrogluteal.
    • Subcutaneous (SQ): 45^{\circ}; upper outer arm, abdomen, anterior thigh.
    • Intradermal (ID): 5^{\circ}\text{–}15^{\circ}; volar forearm, upper back.
  • Recommended Needle Size
    • ID: 27\;\text{g},\;0.5\;\text{in}.
    • SQ: 25\;\text{g},\;5/8\;\text{in}.
    • IM: 25\;\text{g},\;1\text{–}1.5\;\text{in} (thicker adults may need 1.5\;\text{in} or lower gauge).
  • Steps (common to all)
    1. Assemble syringe, verify drug, expel air.
    2. Clean skin with alcohol; dry.
    3. Stabilize tissue (pinch SQ/ID, spread IM).
    4. Insert at correct angle; aspirate per protocol (not needed for vaccines per CDC).
    5. Inject slowly; withdraw; apply gentle pressure/bandage.
  • Complications: local pain, hematoma, infection, nerve/vascular injury (IM), lipodystrophy (repeated SQ insulin).

Needle, Catheter & Suture Sizing Systems

  • Gauge (needles & IV catheters): inverse relationship \text{Diameter} \propto \frac{1}{\text{Gauge}}.
  • Length: measured tip → hub (in inches or mm).
  • Sutures: opposite convention—higher number = thinner & less tensile strength (e.g., 6\text{-}0 thinner than 5\text{-}0). Absorbable (gut, Vicryl) vs non-absorbable (nylon, prolene).

Cervical Specimen Collection

  • Purpose: screen for cervical intra-epithelial neoplasia (Pap/Pap-HPV co-test) & test for STIs.
  • Screening Guidelines: ACS & USPSTF; start age 21, interval 3\text{–}5 yrs depending on age/co-testing.
  • Contraindication: active menstruation (blood obscures cytology).
  • Equipment
    • Speculum with integrated light, water-based lubricant, cervical broom/brush, Ayre spatula, liquid-based cytology vial, optional STI swabs.
  • Technique highlights
    1. Informed verbal consent; empty bladder; lithotomy position.
    2. Warm & lubricate speculum; visualize cervix.
    3. Obtain transformation-zone sample (360° broom rotation + endocervical brush if needed); immediately rinse in preservative.
    4. Label vial; send with requisition indicating HPV co-testing or STI panel.
  • STI Swabs: separate collection from cervix/vaginal vault for \textit{Chlamydia trachomatis}, \textit{Neisseria gonorrhoeae} NAAT, HSV culture, etc.

Wound Closure – Suturing

  • Indication: approximation of viable skin/soft-tissue edges to promote primary intention healing.
  • Contraindication: grossly contaminated/infected wounds (delay closure, consider delayed primary/secondary intention).
  • Suture Techniques taught (MWU core)
    • Simple interrupted (percutaneous).
    • Continuous subcuticular (intradermal).
  • General Principles
    • Cleanse (irrigation \ge 100\;\text{mL/cm} wound), achieve hemostasis, anesthetize (local infiltration or field block).
    • Needle enters skin at 90^{\circ}; bites equal depth/width (~5\;\text{mm} from edge), symmetrical.
    • Slight wound edge eversion to counteract contraction.
  • Suture Selection
    • Face: fine 6\text{-}0\;\text{nylon}; extremities/scalp 4\text{-}0 \text{–} 5\text{-}0; deep fascia absorbable 2\text{-}0 \text{–} 3\text{-}0 Vicryl.
  • Knot security: square knots, tails cut short, knots positioned laterally.
  • Complications: dehiscence, infection, hypertrophic scar, ischemia, needle-stick injury to provider.

Informed Consent

  • Definition: interactive process whereby clinician discloses pertinent information enabling competent patient to make voluntary decision.
  • Core Elements (must be explained & documented)
    • Diagnosis & indication for proposed procedure.
    • Description of procedure (mechanics & expectations).
    • Risks/benefits (common & serious; quantitative if possible).
    • Alternatives, incl. no treatment, with their risks/benefits.
    • Opportunity for questions; assessment of understanding.
  • Benefits
    • Respects autonomy (self-determination), enhances trust, mitigates malpractice risk, facilitates shared decision-making.
  • Competency Criteria
    • Ability to understand information, appreciate consequences, reason about options, communicate a choice.
    • Lacking competency → surrogate decision maker or legal guardianship.
  • Communication Best Practices
    • Plain language; avoid jargon; teach-back method.
    • Certified interpreter (not family) for language barriers.
    • Written materials/videos to reinforce.
  • MWU Informed Consent Checklist (Clinical OSCE)
    1. Self-introduction with credentials.
    2. Verify patient ID (name, DOB).
      3–7. Explain indication, risks, benefits, alternatives, mechanics in lay terms.
    3. Invite & answer questions.
    4. Review consent form; confirm voluntariness; obtain signature.
      10–12. Maintain professional, empathetic, organized demeanor.
    5. Ensure form properly signed/witnessed.
  • Documentation Essentials
    • Date/time, participants, procedure details, risks/benefits, alternatives, patient questions & responses, signature(s) & witness.

Inter-Topic Connections & Practical Tips

  • Numerical sizing parallels: needle & IV catheter gauges inverse to diameter; suture sizing inverse to thickness—reinforce conceptual symmetry for memorization.
  • Aseptic technique is universal thread: venipuncture, IVs, injections, cervical sampling, and suturing all begin with Clean → Prepare → Perform → Dispose.
  • Patient-centered communication spans technical & consent skills: explain steps as you do them to reduce anxiety and improve cooperation (e.g., tourniquet pressure warning, “small pinch” before needle).
  • Ethical overlay: obtaining blood or tissue without adequate consent violates autonomy; conversely, failure to close wound or establish IV in emergent context may breach beneficence—balancing principles is key.

Quick-Reference Equations & Figures

  • Needle entry angles: \text{ID}=5^{\circ}\text{–}15^{\circ},\; \text{SQ}=45^{\circ},\; \text{IM}=90^{\circ}.
  • Venipuncture bevel entry angle: 15^{\circ}\text{–}30^{\circ}.
  • Relationship formula (qualitative): \text{Gauge} \propto \frac{1}{\text{Diameter}} (needles & IV catheters).