1
What is the intensive care unit (ICU)?
The ICU is a specialized area of the hospital designated for patients who are critically ill and may require increased monitoring, hemodynamic support, or airway support. One of the major differences in the ICU is that the nurse-to-patient ratio is higher (usually 1:2). In addition, intensivists , who can provide care for patients, are available. There are many different types of ICUs, and each ICU is equipped to handle various types of patients. The ICU is often referred to as the unit . While naming of the ICUs is not standardized, Table 9-1 shows some commonly used acronyms:
| SICU | Surgical intensive care unit |
| CCU | Coronary care unit |
| NICU | Neonatal intensive care unit |
| NICU | Neuro intensive care unit |
| MICU | Medicine intensive care unit |
| CCMU | Critical care medicine unit |
| TICU | Trauma intensive care unit |
| PICU | Pediatric intensive care unit |
| BICU | Burn intensive care unit |
2
How are patients admitted to the ICU?
Patients can be admitted to the ICU from anywhere within the hospital as well as directly from outside transfers. If the emergency medicine physicians feel that the patient may need intensive monitoring or hemodynamic support, they may request that a patient be directly admitted to the ICU. In addition, after certain procedures such as cardiac catheterization or surgery, a patient may be sent first to the ICU for intensive care and monitoring. If the medical condition of a patient on the general medicine or surgery floor deteriorates, that patient may be transferred to the ICU for more intensive evaluation and management. Patients requiring continued mechanical ventilator support are often cared for in the ICU.
3
How are the monitoring and frequency of care in the ICU different from those on an inpatient floor?
Patient monitoring is increased in the ICU. On the general floor, patient vital signs may be checked by nurses every 2 to 6 hours. In the ICU, the frequency of monitoring by nurses can range from every hour to as often as every 15 minutes, depending on the severity of illness. All patients in the ICU are in a “monitored bed,” usually meaning that they are constantly connected to an electrocardiogram monitor, pulse oxygenation monitor, and blood pressure cuff. Sometimes more invasive forms of monitoring may be used in the ICU. Instead of a blood pressure cuff, which measures blood pressure at intermittent intervals, an arterial line may be used for continuous blood pressure monitoring. In addition, other invasive monitoring can take place in the ICU, such as central venous pressure, cardiac output, and systemic vascular resistance.
4
What is the difference in number of staff per patient in the ICU compared with that on an inpatient floor?
The number of staff per patient is increased in the ICU. On an inpatient floor a nurse may take care of 4 to 6 patients on average, whereas in the ICU the nurse-to-patient ratio is usually 1:2 or less. In addition, other critical support staff, such as the respiratory therapists, are readily available in the ICU.
5
Who directs care of patients in the ICU?
In medicine ICUs, critical care physicians direct care of the patients. These attendings are usually trained in pulmonary medicine or anesthesia and have completed additional training (fellowship) in critical care medicine. In other subspecialty ICUs such as the surgical ICU, trauma ICU, or cardiac care unit, subspecialty attendings will direct the care of patients.
6
How does the staff in the ICU differ from that on other services?
The nursing staff in an ICU may consist of registered nurses who are similar to the floor nurses. However, many nurses either have special ICU training or have obtained certification in critical care.
7
How does a medical student’s role change with patients in the ICU?
Patients in the ICU are more ill and require increased monitoring by both nurses and physicians. Because these patients’ illnesses require more attention, medical students should check on these patients more often. In addition, laboratory results are usually obtained first for ICU patients. Therefore, medical students should check on laboratory values for ICU patients first. Medical students should be very wary about infection control and should wear gloves when indicated. Some patients in the ICU (as well as those on the general floor) may be on contact precautions, requiring the use of gowns inside their room.
8
How does an admission history and physical (H&P) differ for ICU patients?
ICU patients’ medical conditions are more severe, and, therefore, admission histories and physical examinations tend to be complex and require more attention to detail. Many patients who are admitted to ICUs may not be able to provide their history; thus this information is often gathered from other sources including family, friends, paramedics, and other health care providers. The source(s) of information should always be recorded. The information gathered should not only contain the primary reason that brought the patient to seek medical care in the first place but also include a detailed description of the events that led to a deterioration in his or her medical condition to warrant ICU management. In the physical examination, it is important to conduct a full neurologic examination and document it in the note. Finally, as with all patients, the code status should be confirmed and clearly stated in the admission H&P and recorded in the order set by the admitting physician.
9
How is the plan recorded and presented for ICU patients?
For floor patients, the plan is most commonly presented in a problem-based manner. However, for patients in the ICU, the plan is usually recorded and presented by systems. Because of the increased complexity of the conditions of ICU patients, presenting patients in this manner helps ensure that all problems are addressed. Usually, the systems included (with common abbreviations) are neurology (Neuro), cardiovascular (Cardio/CV), pulmonary (Pulm), gastrointestinal (GI), renal, infectious disease (ID), fluids/electrolytes/nutrition (FEN), hematology (Heme), and prophylaxis (Prophy). Neurology, cardiology, or pulmonary are often first on the list, followed next by the system with the most pressing issues.
10
How does the presentation of an ICU patient differ from that of a floor patient?
Presentation of ICU patients often involves significantly more information than that of a floor patient. Therefore, it is important to be succinct but complete. These presentations are often difficult for medical students at the beginning of their clinical rotations, because they require the student to sift through a lot of information to determine the relevant points to present. The best advice may be to practice the presentation beforehand and keep in mind the general order of presentations: (1) events over the past 24 hours; (2) subjective information from the patient (if available); (3) objective data presentation, including pertinent physical examination findings; (4) assessment; and (5) plan by systems.
11
What are the different modes of mechanical ventilation?
Many patients in ICUs require intubation so that a mechanical ventilator can control the patient’s breathing. Although there are several different methods of ventilation, the most common approaches are assisted control, synchronized intermittent mandatory ventilation, and pressure support ventilation. One important tip is that respiratory therapists are quite familiar with these machines and their settings and are a great resource for students to learn from.
12
What is assisted control (AC) ventilation?
This is usually the initial mode used for patients who require ventilation. In this mode, a minimum number of breaths per minute are set. The machine senses whether the patient tries to initiate a breath. If the patient initiates a breath, the machine helps deliver a set tidal volume. If the patient does not initiate a breath, the ventilator delivers a breath at the set rate per minute. In this setting, all breaths are delivered by the ventilator.
13
What is synchronized intermittent mandatory ventilation (SIMV)?
In this mode, a minimum number of breaths per minute are set, just as in AC ventilation. However, when a patient initiates a breath, the machine does not deliver a preset volume. If the machine does not sense a spontaneous breath from the patient, the machine will deliver a breath in synchrony with the patient’s breathing rhythm.
14
What is pressure support ventilation (PSV)?
This ventilation mode is typically used when one is trying to wean a patient off the ventilator. When a patient initiates a breath, pressure is delivered to assist the patient’s breathing. This mode does not deliver any breaths on its own.
15
What are the various settings for mechanical ventilation?
Aside from setting a ventilation mode, the rate, tidal volume, fraction of inspired oxygen (FIo 2 ), and positive end-expiratory pressure (PEEP) need to be set. The rate determines the minimum number of breaths a patient will receive per minute. The tidal volume refers to the volume of air given for each breath. The FIo 2 refers to the percentage of oxygen delivered with each breath. PEEP is sometimes added to prevent the alveoli from collapsing (atelectasis) at the end of each breath.
16
What parameters should be changed if the patient is retaining or blowing off too much CO 2 ?
The respiratory rate and the tidal volume are the first parameters that should be adjusted.
17
How does a patient get taken off a ventilator?
This process of taking a patient off a ventilator is usually referred to as weaning. When determining whether a patient may be ready to be weaned off a ventilator, physicians will estimate the patient’s ability to generate sufficient inspiratory force to allow proper oxygenation and ventilation. The patient will also need to be able to support his or her oxygenation with less than 50% FIo 2 , because without mechanical ventilation this much oxygen support is unreliable. The patient is also assessed to be sure he or she is hemodynamically stable and whether mental and neuromuscular status is appropriate with minimal or no sedation.
Weaning parameters are often used to help physicians determine whether a patient is ready. A common set of weaning parameters is listed in Table 9-2 .
