Coronary care unit

# Overview
A coronary care unit (CCU) is an area of a hospital specialized in the care of patients who are critically ill with heart disease.  The CCU is a subset or subtype of intensive care unit (ICU) care. The role of the coronary care unit (CCU) varies tremendously between hospital centers. In small rural centers, any patient who is being ruled out for a myocardial infarction (MI) may be placed in a CCU.  In contrast, in large urban teaching hospitals, only those patients requiring invasive hemodynamic monitoring with a pulmonary artery catheter, mechanical ventilation, and intraaortic balloon pump (IABP) counterpulsation may be placed in the CCU.  Many hospitals contain both a CCU for critically ill patients and units called either an "intermediate care unit", "progressive care unit", "telemetry floor" or "step down unit" for patients who are not as crtically ill. These units provide a level of care that is intermediate to that of the intensive care unit and that of the general medical floor. These units typically serve patients who require cardiac telemetry such as those with unstable angina. In those hopsitals who provide cardiothoracic surgery services, there is often a coronary care unit dedicated to the management of patients following coronary artery bypss grafting (CABG), aortic valve surgery or other thoracic surgery.

# History of the CCU
Coronary care units first appeared in the 1960s when it was observed that close monitoring by specially trained staff, rapid cardiopulmonary resuscitation and optimal medical management were associated with a reduction in mortality from complications of acute MI. The first description of a CCU was provided in 1961, and early CCUs were located in Sydney, Kansas and Philadelphia. Studies published in 1967 demonstrated that hospitalization in a coronary care unit was associated with improved clinical outcomes.

# Characteristics
Modern coronary care units are staffed by highly trained individuals who practice evidence based medicine to improve clinical outcomes.  Guidelines are often in place to assure access to updated evidence based data regarding the optimal managment of patients. Equipment is available for invasive hemodynamic monitoring so that early signs of hypotension, mechanical complicaitons and cardiogenic shock can be promptly detected and treated.  Likewise, continuous monitoring of the ECG is available so that arrhythmias are immediately recognized and cardioversion or defibrillation can be performed promptly.  A CCU also supports mechanical ventilation, intraaortic balloon pump counterpulsation and the use of temporary pacemakers.

# CCU Staffing and Personnel

## Credentials
Requirements regarding the level of certification for nurses varies internationally.  In the United States, policies will vary between institutions, but the following are often recommended for nurses staffing the CCU:
- Certification in critical care nursing (CCRN, Critical Care Registered Nurse) through the American Association of Critical-Care
- Advanced cardiac life support certification (ACLS)

## Staffing Ratios
Higher nurse-to-patient ratios have been associated with improved clinical outcomes in the intensive care setting.    There is ongoing debate regarding the optimal nurse-to-patient ratio.  Some states such as California have attempted to mandate staffing ratios for spcific intensive care areas such as 1:2 in the intesive care unit setting, 1:4 in a telemetry setting, and 1:5 in a telemetry unit.  Despite such mandates, variability in staffing ratios remains.  Rather than mandating a fixed staffing ratio, it is reasonable to recommend a variable staffing ratio based upon the acuity of a group of patients and the competency of a group of providers.

# Management of the Patient on Arrival to the CCU
Initial efforts on arrival to the CCU should assure that there is a seamless transition from the emergency room or cardiac catheterization laboratory.  Nurses and physicians caring for the patient should assure the following when giving "report" to each other:
- A complete accounting of all medications administered should be undertaken.  While it may be clear what parenteral agents are actively infusing, it may not be clear what oral (e.g. aspirin, clopidogrel, metoprolol) and subcutaneous agents (e.g. unfractioned heparin, enoxaparin) have been administered. Notes can be illegible.
- The infusion rate of all parenteral agents should be reviewed.
- The compatability of parenteral agents being infused should be reviewed. (e.g. UFH may cause the precipitation of a fibrinolytic agent such as rPA).
- The timing of the last dose of all medications should be recorded.
- The timing of all planned doses of drugs should be recorded.
- Allergies should be recorded.
- Contact information for the next of kin and a health proxy should be recorded.
- Known lab values should be recorded. Lab values that are pending should be noted.
- The hemodynamic status of the patient must be reviewed.

# Standing Orders on Admission to the CCU
It is reasonable to have a standard set of standing orders for a CCU. Elements of a set of standing orders might include the following:
- Aspirin 325 mg PO daily
- Clopidogrel 75 mg daily among patients who have undergone either primary percutaneous coronary intervention or fibrinolytic administration for ST-segment elevation myocardial infarction
- Dosing of a glycoprotein IIb/IIIa inhibitor intravenous infusion among patients who have undergone primary percutaneous coronary intervention for ST-segment elevation myocardial infarction
- Dosing of an antithrombin, including titration as needed
- Dosing of a beta-blocker.
- Acutely and during the first 24 hours among patients without significant bradycardia (<60 beats per minute), hypotension (systolic blood pressure <100 mm Hg) or moderate or greater heart failure (Killip Class II or above): 5 mg IV metoprolol over one to two minutes, which should be repeated every five minutes for a total initial dose of 15 mg. If this is tolerated, then administer the first dose of 50 mg of PO metoprolol 15 minutes after the third IV dose. Repeat this 50 mg dose q 6 hours.
- After the first 24 hours: Metoprolol 50 mg PO every 6 hours.  If this dose is tolerated, then administer 200 mg of controlled release oral metoprolol daily
- Analgesic agent (non-steroidal anti-inflammatory drugs are contraindicated in the setting of acute MI)
- Stool softener
- Anxiolytic agent
- Daily weight
- Height on admission
- Specify vital signs
- Specify laboratory checks
- Monitor oxygen saturation and administer 2 liters per minute in the absence of COPD
- Monitor ECG continuously, specify 12 lead q 8 hours for 24 hours and then daily thereafter
- Bedrest and advancement of activity levels

# Electrocardiographic Monitoring in the CCU
Ongoing monitoring of the electrocardiogram in the CCU allows for early detection and treatment of arrhythmias. CCU nurses and physicians must be competent in the following:
- Placement of leads appropriate to the infarct location
- Placement and interpretation of right sided leads
- Recognition of arrhythmias and conduction disturbances
- Calculation of the corrected QT interval
Unless the telemetry unit is designed electrically to detect ischemic changes in the ST segment, it should be realized that the ST segments may shift in the absence of ischemia when standard telemetry units are used.  12 lead ECGs are therefore neccessary to evaluate the patient for ischemic changes.

# Hemodynamic Monitoring in the CCU
Unless a patient is hypotensive and requiring pressors, non-invasive cuff measurements should be sufficient and should be measured at a frequency that matches the acuity of the patient.

# 2004 ACC/AHA Guidelines for the Management of Patients With ST-Elevation Myocardial Infarction (DO NOT EDIT) 

# Sources
- The 2004 ACC/AHA Guidelines for the Management of Patients With ST-Elevation Myocardial Infarction 
- The 2007 Focused Update of the ACC/AHA 2004 Guidelines for the Management of Patients with ST-Elevation Myocardial Infarction