Elective procedures

For most patients, diagnostic cardiac catheterization is performed as an elective procedure. It should be deferred if the patient is not prepared either psychologically or physically.

Urgent procedures

If the patient’s condition is unstable because of a suspected cardiac disorder, such as acute myocardial infarction, catheterization must proceed. In the event of decompensated congestive heart failure (CHF) in patients with acute unstable coronary syndromes, rapid medical management is needed. Although a patient must be able to lie flat for easy catheter passage, patients with acute cardiac decompensation may benefit more from aggressive management in the catheterization laboratory where intubation, left ventricular (LV) mechanical support devices, and vasopressors can be instituted rapidly before angiography, and a rapid decision made for revascularization.

Consent for the procedure

Consent may be obtained by the operator or his or her assistant but is usually obtained by a physician. The person obtaining consent should do the following:

• 1.
  

  Explain in simple terms what procedure will take place, for what reason each step of the procedure will occur, the roles of the team performing the procedure, and what is expected to be learned from the test.

  
  
• 2.
  

  Explain the risks for routine cardiac catheterization. Major risks include stroke, myocardial infarction, and death (usually less than 1 in 1000). Minor risks include vascular injury, allergic reaction, bleeding, hematoma, and infection. If PCI is anticipated, consent for this should be obtained and options should be discussed in advance of the procedure such as medical therapy, stenting, or coronary bypass surgery.

  
  
• 3.
  

  Explain any portions of the study used for research and the associated risks (e.g., electrophysiologic study—perforation, arrhythmia [<1:500]; pharmacologic study—varies depending on drug and study duration; intracoronary imaging or sensor-pressure wire study—spasm, myocardial infarction, embolus, dissection [<1:500]).

  
  
• 4.
  

  Provide the necessary information and explanation but do not overwhelm the patient. It is good practice to include the family when explaining what will happen and possible outcomes.

After explaining all aspects of the cardiac catheterization for informed consent, it is important to remember that the final decision to undergo the procedure is always the patient’s. Informed consent entails a shared decision-making process, in which there is a two-way exchange of pertinent information. This information allows the patient (and family) to make a fully informed decision based on his or her expectations, risks of the procedure, and choice of alternatives. If the patient is reluctant to have the catheterization, the procedure can be deferred until the referring physician speaks to the patient to clarify why the procedure is necessary. A reluctant patient should never sign the consent form. When possible, the family should be present when the procedure is discussed. This approach encourages a cooperative and generally sympathetic appreciation of the procedure, the risks, and expected outcome.

Communication with patients: A nonmedical person’s understanding

The clinician establishes rapport and builds the patient’s confidence by listening and explaining. The procedure should be discussed with the patient in terms that he or she can understand. The purpose of the procedure should be clear such as “to look at the arteries in the heart” (coronary arteries) and “to examine the heart muscle” (ventricular function). Simple terms are best so that the patient can grasp the concepts. The clinician should explain what small catheters are (plastic tubes similar in size to spaghetti) and that they will be used to put x-ray contrast media (“dye”) into the arteries supplying blood to the heart. Explain that the procedure is not painful because the arteries are generally not sensitive to the passage of the small catheters. The heart muscle may be weakened (infarcted) in certain areas, and the way to identify this weakness is to take x-ray pictures of the “main pumping chamber” (i.e., the left ventricle). This example of a simple, forthright explanation facilitates the operator team–patient relationship so that confidence in the operator and team performing the procedure is established.

Laboratory atmosphere: The patient’s confidence builder

• 1.
  

  In the laboratory, a confident, professional attitude should be adopted by all personnel at all times. Straightforward routine communication should occur quietly and without alarming tones. Patients should be addressed directly, by name, to let them know what their instructions are, as opposed to requests or communications to co-workers.

  
  
• 2.
  

  The circulating team members should be confident, reassuring, and professional in every respect. The patient feels helpless and is tuned in to all types of stimuli (especially verbal).

  
  
• 3.
  

  Extraneous conversation is distracting for the patient and the operators. This is especially true when the patient is draped in a manner that does not allow him or her to see his or her surroundings. In the laboratory, all players should be in the game; that is, focused on the patient’s needs and safety, which become paramount goals.

  
  
• 4.
  

  Communication with the patient (and family) before, during, and after the procedure ensures a satisfied and well-cared-for individual. Communication among the team members in a professional, courteous, and quiet tone builds patient confidence and helps the procedure go smoothly.

  
  
• 5.
  

  Factory worker attitudes of “another coronary” or “another ST-segment elevation myocardial infarction” (STEMI) should be avoided. Each procedure is potentially life threatening and should be undertaken seriously and with concern as if each patient were a family member.

  
  
• 6.
  

  Cardiac catheterization is stressful to the patient and the operator team. This stress should be minimized by thoughtful preparation and professional attention to detail. Practical notes for the new operator include the following:

  
  
  
  
  • a.
    

    Immediately before the catheterization in the laboratory, a brief reiteration of the history ensures that no interval change has occurred since the last interview.

    
    
  • b.
    

    A reexamination of the patient’s ECG is essential.

    
    
  • c.
    

    A brief examination of the patient (checking heart sounds, breath sounds, and carotid and peripheral pulses) should be routine immediately before and after cardiac catheterization. No patient should be studied without the operator’s full understanding of the clinical conditions and results of previous catheterizations and other pertinent laboratory data.

    
    
  • 
    

    When on the catheterization table, the patient remembers two major potentially painful points of a case: (1) the initial introduction of the local anesthetic (and sometimes radial sheath introduction) and (2) any discomfort experienced after the study has been completed. Such discomfort usually occurs while the operator or nurse is holding the femoral puncture site. If the local anesthetic injection is performed too quickly or if the arterial closure or compression after the procedure is difficult or painful, the patient will remember that the physician who performed the catheterization “hurt me.” The period between the two events is often forgotten (thanks to premedication), but these two points should be kept in mind as the major new-operator take-home messages. Patients cannot discern the operator’s skill or level of accomplishment during the procedure, but they judge the operator (and the team) on the manner and care they receive at the beginning and end of the study. Skill and accomplishment during the procedure are essential, and these are developed during the new operator’s training period.

  
  
  
  
• 7.
  

  General catheterization orders:

  
  
  
  
  • •
    

    Before catheterization, preferably the preceding night, precatheterization orders should be written.

    
    
  • •
    

    All medications and procedural premedications should be tailored to the patient and timing of the catheterization. If the patient is using long-acting insulin (neutral protamine Hagedorn [NPH]), the dose should be reduced by 50% and the patient should not eat breakfast. The patient should be watched carefully for hypoglycemic reactions (e.g., shaking, confusion, slurred speech).

    
    
  • •
    

    A more recent suggestion to avoid dehydration and increased chance of contrast-induced nephropathy is to permit or encourage the patient to drink water before the procedure and confine the nothing-by-mouth (NPO) orders to solid foods or dairy products before the procedure.

  
  
  
  
• 8.
  

  Patients should wear their glasses and dentures in the laboratory to make communication easier.

In-laboratory preparations and the time-out

The staff of the cardiac catheterization laboratory is responsible for patient preparation before the start of the procedure. On the patient’s arrival in the laboratory, a staff member should review a brief checklist to ensure that all preprocedural requirements have been met. A sample checklist follows:

• •
  

  Check the patient’s ID band and known allergies.

  
  
• •
  

  Check laboratory results (key tests: hemoglobin, platelet count, electrolytes including blood urea nitrogen, creatinine).

  
  
• •
  

  Check blood pressure, all pulses (arms and legs), and baseline ECG.

  
  
• •
  

  Anticoagulant status: Check the international normalized ratio (INR) and partial thromboplastin time (PTT) and, if on heparin, the activated clotting time (ACT).

  
  
• •
  

  Recheck childbearing potential (patient may need β-human chorionic gonadotropin level).

  
  
• •
  

  Verify that the proper paperwork has been copied and filled out for the procedure and confirm that the consent form has been signed.

  
  
• •
  

  Assess the patient’s understanding of the procedure and answer the patient’s questions.

  
  
• •
  

  Check that the oral airway forms for the procedure are signed and in the chart. If not, make arrangements for their completion before the procedure.

  
  
• •
  

  Check that the intravenous (IV) line is secure and patent.

  
  
• •
  

  Check that the patient has ingested nothing solid by mouth before the procedure.

  
  
• •
  

  Check whether premedications were given as ordered.

  
  
• •
  

  Start documentation of the precatheterization condition and note any physical deficits (abnormal neurologic examination, bruising, or bleeding sites).

Catheterization suite preparations

Before the start of the catheterization procedure, the staff performs the following tasks:

• 1.
  

  Establish ECG monitoring. The ECG should be considered the first of the two major lifelines. The heartbeat is monitored for rate and rhythm during the entire procedure. It is the responsibility of the staff to place the electrodes and lead wires in such a fashion that a quality trace is obtained. Care must be taken that the electrodes and lead wires do not interfere with the movement of the x-ray and cineangiographic unit. All leads should be secure, and a good signal should be present before the application of sterile drapes; it is difficult to reach under the sterile drapes to reattach loose lead wires once the procedure has begun. Radiolucent leads permit complete 12-lead ECG monitoring but are more prone to breakage than heavier cable leads.

  
  
• 2.
  

  Establish IV access. The second lifeline is IV access for routine medications and fluids as well as for emergency resuscitation measures. Without good IV access, emergency drugs to counteract vagal or allergic reactions will not be effective. When the patient is in the laboratory, the nurse or physician may identify the need for additional sedation or analgesia before the start of the procedure. The IV line is also important for hydration after cardiac catheterization.

Caution must be exercised when premedicating elderly patients. If meperidine (Demerol), fentanyl, or morphine is used, a narcotic antagonist, such as naloxone (Narcan), should be available. Flumazenil (a benzodiazepine antagonist) should also be available if diazepam (Valium) or midazolam (Versed) is used.

The time-out

In any catheterization laboratory, preparations can be hectic, perhaps even frantic at times. This frenetic pace can cause problems, important steps can be missed, and patient safety can be compromised. As part of procedural safety, every patient coming to the laboratory must be assessed for his or her suitability for conscious sedation and potential complications of the catheterization procedure. Every laboratory is required to perform a preprocedure safety review, called the time-out ( Fig. 1.3 ). In the time-out before sedation, the team verifies the right patient is in the room, the right procedure is going to be performed, the right operative site will be used, and whether the patient has renal failure, allergies, or is being treated with anticoagulants so that the team has no concerns about whether to proceed. At this time, the team agrees to proceed and then specifies what analgesia and sedation dose will be given. Time-out is a Joint Commission requirement.

The time-out towel is a reminder to conduct a safety check before proceeding with the procedure.

(Reprinted with permission from Cath Lab Digest. Copyright HMP Communications.)

Sterile preparations

Cardiac catheterization occurs in an operating room environment, and all preparations for the procedure must be performed using aseptic technique, with personnel in scrubs, protective hats, masks, and gowns. Some laboratories do not require masks during the back-table setup.

Rules for observers in the laboratory

Some hospitals have policies that limit nonhospital personnel from being in the catheterization laboratory without prior consent of the patient. Any observers in the angiographic room should respect the professional atmosphere and keep extraneous conversation to a minimum. Observers should adhere to the policy of the laboratory and wear scrubs or paper gowns and a lead apron as protection against scattered radiation. Observers should avoid sterile fields and should be aware of the precautions necessary for protection from blood and other body fluids.

No one but catheterization laboratory personnel should ever manipulate or adjust any device, equipment, or medication system in the laboratory. To prevent observers who are not laboratory personnel from becoming overly enthusiastic and attempting to assist the nurses or physicians, they should never be given sterile gloves. This is important to avoid potential liability for the laboratory, hospital, and staff.

Conscious sedation for invasive cardiac procedure

The purpose of conscious sedation is to minimize patient anxiety, discomfort, and pain associated with the procedure. The following criteria define conscious sedation:

• 1.
  

  The patient at no time loses protective reflexes.

  
  
• 2.
  

  The patient retains the ability to maintain an open airway continuously without help.

  
  
• 3.
  

  The patient responds appropriately to verbal and physical stimulation.

If the patient can no longer do the things listed, the sedative technique evolves to deep sedation or general anesthesia. At this point, the monitoring and care of the patient must be elevated to avoid an adverse outcome.

A conscious sedation protocol has four major components: (1) preprocedural baseline assessment, (2) drug dosage and administration, (3) patient monitoring, and (4) postprocedure monitoring and assessment and discharge criteria.

Preprocedural assessment

Before the administration of sedative agents, the patient should have a complete assessment of his or her current physical condition. The clinician should pay particular attention to any preexisting conditions that would put the patient at risk for an adverse outcome if sedatives are administered. A preprocedural evaluation should include a review of the major organ systems, the time and type of the last oral intake, a history of drug and alcohol use, a history of smoking, and a history of previous experience with sedative agents.

Preprocedural fasting is the rule. Sedative agents may impair airway reflexes, placing the patient at increased risk for aspirating gastric contents. For elective procedures, these risks can be minimized by allowing sufficient time for gastric emptying before the procedure. The patient should be NPO for solids and nonclear liquids after midnight or at least 8 hours before the start of the procedure. Clear liquids may be appropriate 1 to 3 hours before the procedure, depending on the type and dose of the sedative agent to be used.

Physical examination and airway assessment

An airway assessment should be part of the preprocedural routine. Most preprocedural checklists include the Mallampati classification, which is used to predict the ease of intubation. Mallampati scoring is as follows:

• 
  

  Class 1: full visibility of tonsils, uvula, and soft palate

  
  
• 
  

  Class 2: visibility of hard and soft palate, upper portion of tonsils, and uvula

  
  
• 
  

  Class 3: soft and hard palate and base of the uvula are visible

  
  
• 
  

  Class 4: only hard palate is visible

A high Mallampati score (class 4) is associated with more difficult intubation and a higher incidence of sleep apnea. Factors associated with difficult airway management also include:

• 1.
  

  A history of sleep apnea, snoring, or stridor

  
  
• 2.
  

  Dysmorphic jaw or facial features

  
  
• 3.
  

  Advanced rheumatoid arthritis

  
  
• 4.
  

  A short neck with limited extension caused by obesity, mass, or injury

  
  
• 5.
  

  Mouth or jaw irregularities or deformities, including loose or capped teeth or dentures.

American Society of Anesthesiologists Physical Status Classification

The American Society of Anesthesiologists Physical Status Classification ( Table 1.5 ) is helpful in determining the patient’s eligibility for conscious sedation. It uses a 1 to 5 classification range, with 1 being a healthy patient and 5 being a moribund patient. Procedural sedation is appropriate for patients in classes 1, 2, and 3. Patients in class 4 and higher are better suited for general anesthesia. There are several contraindications to conscious sedation that include:

• 1.
  

  Recent (<2 hour) ingestion of large food or fluid volumes

  
  
• 2.
  

  A physical class 4 or greater

  
  
• 3.
  

  A lack of support staff or monitoring equipment

  
  
• 4.
  

  A lack of experience/credentialing on the part of the clinician.

Drugs for conscious sedation

First-line drugs and dosages for conscious sedation are listed in Table 1.7 .

Postprocedure monitoring and discharge criteria

Patients who receive conscious sedation should be monitored for 1 to 2 hours before discharge. During this time the patient should be assessed and monitored with the same parameters used in the preprocedural assessment. When the patient returns to baseline, discharge is appropriate. The following discharge criteria should be met before the patient is sent back to the floor or home:

• 1.
  

  The Aldrete score has returned to baseline (summed Aldrete scores of 9 or 10).

  
  
• 2.
  

  At least 2 hours have elapsed since the last dose of sedative agents.

  
  
• 3.
  

  Vital signs have returned to baseline.

  
  
• 4.
  

  Ventilation (respiratory rate and oxygen saturation) has returned to baseline.

  
  
• 5.
  

  The patient is mentally alert, and all protective reflexes are intact.

Outpatients who are being discharged to home should be able to ambulate appropriately for their age and condition. An escort should be available, and the patient should be instructed about not driving a motor vehicle for an appropriate period.

Postcatheterization check-up

The operator should check on the patient several hours after the procedure. Vital signs should be normal. Low blood pressure is usually a result of diuresis and responds to normal saline. Tachycardia with low blood pressure indicates blood loss until proven otherwise. The arterial access site should be checked for pain and hematoma. The operator should check the groin site and distal pulses in legs or the wrist for loss of pulse. Urine output should be >30 mL/h. Low urine output may reflect unsatisfactory volume replacement or early onset of contrast-induced renal failure. A cool or painful extremity requires immediate assessment to determine whether thrombus, spasm, or vasoconstriction is responsible for arterial occlusion. Limb ischemia, including the arm for radial cases, or an enlarging hematoma requires urgent consultation with a vascular surgeon, repeat angiography, and at times an urgent return to the catheterization laboratory.

Angiogram review

To provide the patient and family with an understanding of the coronary artery disease or other findings, a preliminary schematic diagram of the heart and coronary arteries can be provided. A similar diagram should be put in the chart to help others understand the findings. A catheterization instruction book is helpful and may contain a blank standard diagram ( Fig. 1.4 ). The booklet explains the catheterization procedure and the possible meaning of various findings on the coronary angiogram. In some cases, reviewing the actual coronary cineangiograms with the patient and family members may be helpful. After discharge, the patient may wish to see the angiograms to understand the disease better and to ask questions and receive answers specifically with regard to future treatment (after the operator discusses the findings and plans with the referring or primary care physician). Taking the time to explain the findings by referring directly to the diagram or cineangiographic film is rewarding. “No one ever took time to explain my heart problem this way, and now I understand what is wrong” is a frequent comment. The risk of a patient becoming alarmed or depressed after viewing the cineangiogram has not been borne out by experience with thousands of patients and their families. The additional burden of taking the time to show the angiograms to the patient is worth the effort. In some busy laboratories, this approach may not be feasible, but with images on disks, almost every laboratory has an open computer to share the angiograms with the patient. The operator should always discuss the findings and possible recommendations with the primary physician first because catheterization is principally a consultative service.

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