2.3 Screening, NPO, Education & Consent

Screening, NPO, Education, and Consent

Outline leaves 1.B.3 Scheduling and Screening, 1.B.4 Patient Education, and 1.B.5 Consent are the gates between a name on the schedule and a legal, metabolically safe arterial puncture. The CI technologist does not write the order and does not obtain informed consent, but the technologist is often the last person who can still stop an unsafe elective case.

Scheduling and Screening

Screening begins when the case is scheduled, not when the patient hits the door. Confirm the procedure actually ordered (diagnostic LHC, planned PCI, right-heart catheterization, or a structural case such as transcatheter aortic valve replacement (TAVR)). Confirm laterality of access preferences, anesthesia needs, and whether mechanical support or a hybrid operating room is required.

Sequencing of imaging is a screening decision. Elective structural work typically needs recent echocardiography and often a dedicated CT (annular sizing, coronary heights, access vessels) before the implant date — doing the implant first and the CT after is not a sequence. In ischemic work, diagnostic catheterization and PCI in the same sitting is standard when consent covers ad hoc intervention and anatomy is suitable; staging PCI is a physician decision when contrast, radiation, complexity, or incomplete consent stand in the way.

Contrast administration is screened with a current creatinine and eGFR. If the value is missing, outdated per facility policy, or markedly worse than baseline, the elective case pauses. Hydration protocols, contrast minimization, and nephrology input are physician orders; the technologist's screening job is to surface the number before the first injection. Postprocedure screening includes a plan for renal follow-up when ordered and a reminder that metformin restart is not automatic.

Pregnancy screening belongs on every person who could be pregnant, before fluoroscopy. A urine or serum test per protocol, plus the patient's statement, is documented. A claim that the patient is being careful is not a pregnancy test.

NPO Status

Nothing by mouth (NPO) reduces aspiration risk under sedation. Typical adult guidance used in many labs, adapted from anesthesia fasting practice, is about 6 hours for solids and about 2 hours for clear liquids. Facilities publish their own tables (some still say NPO after midnight). ARRT tests the concept — that elective sedated contrast cases require an appropriate fast, and that solids and clears have different clocks — not a single unpublished national number. Always follow the written facility protocol and document exceptions.

Patient Education: Preparation, Diet, and Medications

Education is screening's twin. Tell the patient, before the arrival day when possible:

• Preparation: which medicines to bring, who must accompany them if sedation is planned, and that jewelry and nicotine patches at the access site come off.
• Diet: the NPO clock, including that clear liquids may be allowed closer to start per protocol, and that a heavy meal the night before is not the same as a sip of water.
• Medications — hold versus continue:
  • Insulin and oral diabetes agents: doses are often reduced the morning of NPO; hypoglycemia in holding is preventable.
  • Anticoagulants: warfarin and DOACs are commonly held for a drug-specific interval before elective arterial access; do not assume the patient did so.
  • Metformin: held around iodinated contrast per protocol, especially with reduced eGFR, and restarted after renal function is checked as ordered.
  • Aspirin and prescribed P2Y12 inhibitors: often continued for coronary work; holding them because of bleeding without an order can leave a stent unprotected.
  • Diuretics and antihypertensives: follow the physician's written plan; a patient who took a full diuretic dose and then fasted all morning may arrive hypotensive.

Use teach-back on the two items that cause the most day-of cancellations: the last solid meal time, and the last dose of a DOAC or metformin.

Consent: Informed Written, Verbal, and Emergent Implied

Informed consent is a physician conversation, not a signature-harvesting task for the CI technologist. The physician explains the nature of the procedure, benefits, alternatives, and material risks, and answers questions. The patient (or legal surrogate) then signs. Verbal consent may be used when a signature is physically impossible but the patient can understand and agree; it is still the physician's consent, documented contemporaneously.

Risk language differs by procedure, but the core CI list the patient must hear includes stroke, myocardial infarction (MI), death, bleeding, emergency coronary artery bypass grafting (CABG), contrast nephropathy, and radiation injury. Add procedure-specific risks: stent thrombosis and the need for DAPT for PCI; annular rupture, pacemaker, and vascular injury for transcatheter valves; tamponade for structural transseptal work.

Who obtains consent: the physician. Who witnesses and verifies: the CI technologist and circulating RN confirm that a dated, procedure-named consent is present, that the patient appears to understand or that a surrogate signed, and that the time-out reads the same procedure that was consented. The technologist does not independently obtain consent while the operator is scrubbed, and a waiting-room relative's shrug is not consent for an elective case.

Implied Consent — Emergencies Only

Implied consent applies when a patient is unable to consent and delay would cause death or serious harm — the unresponsive STEMI, the cardiac arrest who needs emergent angiography, the hypotensive tamponade who needs immediate pericardiocentesis. The physician proceeds and documents the emergency exception. Family is contacted as soon as practical; that call does not precede the balloon in an arrest.

Exam trap: implied consent is not for the anxious but competent patient who just wants it over with and declines to hear stroke risk. It is not for the elective patient whose family is stuck in traffic. It is not for adding an elective PCI to a diagnostic-only consent because the lesion looks easy. Anxiety is not an emergency. If the patient is competent, you slow down and the physician completes informed consent — or you do not stick.

A second trap is assuming hospital admission consent covers arterial access, stents, and structural implants. It does not. Procedure-specific informed consent, or a documented emergency exception, is required.

Putting the Gate Together

Screening (NPO, pregnancy, eGFR, medication holds, imaging sequence) plus education plus a valid consent is the condition of starting. The CI technologist's professional voice is the last check: if the consent says diagnostic, the patient ate solids two hours ago, or the pregnancy test is missing, you stop the line. That stop is patient care, not insubordination.