Chapter 12

Approach to Supportive Care and Noninvasive Bedside Monitoring

Patients are commonly admitted to the intensive care unit (ICU) for four principal reasons: (1) ICU level of monitoring, (2) intensive nursing care, (3) specialized procedures, and (4) therapies that carry special requirements or risk. On ICU admission, patients have certain needs related to their admitting diagnoses such as gastrointestinal hemorrhage, septic shock, or acute renal failure. In addition, all patients require special attention to several universal needs. Meeting these individual and common needs is the collective goal of ICU supportive care.

Considering a basic checklist of supportive care for every ICU patient is important for several reasons. First, in the rush to treat a critically ill patient’s acute problems, one may overlook simple but important care. Second, serious illness invariably affects remote systems not involved in the primary pathophysiologic process. Third, treatment aimed at correcting one problem may create others. Supportive ICU care conforms to the general schema of admitting orders for any hospitalized patient (Table 12.1). In addition, it is helpful to systematically address possible needs for each organ system (“from head to foot”), including neurologic, ophthalmologic, otolaryngologic, integumentary, endocrine, metabolic, respiratory, cardiovascular, gastrointestinal, renal, musculoskeletal, and integumentary. In the head-injured patient, for example, failure to specifically address prevention of deep venous thrombosis, gastric stress ulceration, or skin injury may have serious consequences.

TABLE 12.1

Basic Orders for Patients Admitted to the ICU

BASIC ORDERS	ICU CONSIDERATIONS
Diagnosis	Are there diagnosis-specific protocols or pathways? Do the patient’s characteristics match admission criteria?
Condition	All but patients admitted for monitoring should be identified as “critical.”
Allergies	Extremely important to inquire and document any drug allergies.
Activity	Consider careful and explicit rationale for restraints, special beds, positioning.
Vital signs	Each ICU has its own frequency of vital signs. Specify use of non-invasive monitors (e.g., pulse oximetry); list parameters for physician notification (e.g., call physician for heart rate > 120 or < 60).
Diet	Specify use of nasogastric or duodenal feeding tubes where appropriate; estimate caloric requirements; consider special electrolyte or fluid needs; maintain some enteral feeding for patients receiving hyperalimentation, unless contraindicated (Chapter 15). Use nutrition consultation and special hyperalimentation order sheets. Consider measuring nitrogen balance, where appropriate.
Diagnostic procedures	Will alert nursing staff to coordinate offsite transport or to prepare the equipment for bedside procedures.
Fluids	Pay attention to decreased, insensible water loss in ventilated patients (may gain up to 500 mL/24 h).
Special considerations	Eye protection for paralyzed patients; mouth care for intubated patients.
Preventive measures	Use subcutaneous heparin or pneumatic compression devices for deep venous thrombosis prophylaxis; use enteral feeding, sucralfate, proton pump inhibitor, or H₂ blocker for stress ulcer prophylaxis for patients in high-risk group (Box 12.1).
General medications	Assure adequate control of pain and anxiety (Chapter 5); write for a PRN (as needed) sedative for sleep (Chapter 44).
Special medications	Particular care should be given to drug interactions, impaired renal and hepatic clearance, and decreased blood flow in shock states (Chapter 17).

The value of formal checklists in the critical care setting has recently received much attention in the medical literature, with demonstrations of the significant impact of checklist use on central venous catheter infection rates and other outcomes.

Body Positioning

Most individuals admitted to the ICU are confined to bed for the initial part of their illness. The clinician must go far beyond the usual prescription of “bed rest” for the ICU patient, as the hospital bed becomes that patient’s immediate and total physical environment. Bed confinement confers risks of aspiration, pressure ulcers of skin and soft tissue, musculoskeletal problems, abnormal cerebral perfusion, increased oxygen consumption, and basic discomfort. Far from being a simple matter of placing the patient in a comfortable position, positioning has become the subject of considerable study.

By default, most patients are initially placed in the supine position and turned regularly onto their sides to prevent both prolonged exposure (> 2 hours) of body protuberances to pressure and also atelectasis of dependent lung segments. Despite nearly universal support for the “2-hour benchmark,” a study across 40 intensive care units documented that the mean time between turns approached 5 hours, and another investigator observed 2-hourly changes in position in only 3% of ICU patients over an 8-hour observational period.

Improved reliability of periodic turning partly explains the increasing use of rotational therapeutic beds. These devices perform timed alternating lateral positioning through sequential inflation or other mechanical means. One large prospective randomized study and a meta-analysis identified decreased development of pneumonia with rotational therapy. Lateral positioning may improve oxygenation in patients with severe unilateral pneumonia, who often respond favorably when the “good” (nonconsolidated) lung is “down” (in the dependent position). The rationale for this improved oxygenation is that gravity favors blood flow to the dependent, uninvolved lung and increases pulmonary blood flow to the better-ventilated alveoli. This effect of gravity on pulmonary blood flow improves ventilation/perfusion matching (fewer alveoli with low ventilation/perfusion) and decreases shunting through fluid-filled alveoli (whose ventilation/perfusion = 0), and both changes improve oxygenation. In evaluating a critically ill patient, it is important to interpret alterations in oxygenation in the context of any positional changes that may affect ventilation-perfusion matching.

Some centers treat patients with acute respiratory distress syndrome (ARDS) by periodic turning to and from the prone position to improve oxygenation (see Chapter 73). Extensively investigated, prone positioning consistently produces transient but significant improvement in oxygenation indices in many patients, but without conferring survival or other outcome benefits.

In the case of severe hemoptysis (usually > 300 mL/24 hours) from a unilateral lesion, the opposite recommendation applies: turn patients so that the bleeding lung is in the dependent position (“bad” lung down). In this circumstance, gravity deters blood from spilling across the midline to the contralateral, nonhemorrhaging lung. This maneuver may be lifesaving in an emergent situation (see Chapter 79).

For many years, patients were routinely placed horizontally (flat) in the supine position for ease of care. This fully recumbent position facilitated the calibration and zeroing of transducers, routine nursing care, and the preventon of falls. Unfortunately, supine positioning increases the risk of aspiration (as demonstrated by tracer studies), nosocomial pneumonia, and mortality. For this reason, keeping the head of the bed elevated 30 to 45 degrees, especially in mechanically ventilated patients or those receiving gastric tube feedings, has been recommended in the ICU. The Centers for Medicaid and Medicare Services (CMS) has considered making maintaining head of bed elevation > 30 degrees reportable as a quality process measure, along with ventilator-associated pneumonia (VAP) as an outcome measure. Important factors make VAP an unreliable outcome measure, although head-of-bed elevation is becoming widespread.

Some patients with neurologic disease may benefit from elevating the head of the bed to 30 degrees, which reduces intracranial pressure up to 10 mmHg. However, elevating the patient’s upper body may create extra shear stress exposure to the skin of the back, sacrum, and lower extremities, increasing the risk of skin injury and breakdown (Chapter 42).

Any special requirements for body positioning must be discussed among the entire ICU care team. The documented difficulty of maintaining compliance with frequent position changes, risk of back and other stress injury to the clinician, and potential danger of malposition or disconnection of catheters during movement all summate to require well-planned and meticulously implemented position changes by the multidisciplinary team. Unfortunately, because of their spectrum and the severity of their critical illness, sicker patients receive less frequent position changes. Thus, formal team communication, visual cues, and feedback of performance data all enhance the reliability of positioning among other standard ICU work.

Skin Care (see also Chapter 42)

Risk Factors for Skin Injuries

The skin is the first line of the body’s defense against the external environment, but multiple factors conspire to violate these defenses in the ICU patient. Whether chronically ill and debilitated, or acutely and catastrophically ill, the ICU patient may have poor nutrition, limited anabolic capacity, or both. The skin becomes fragile, unable to resist normal assaults, and lacks the capacity to heal. Low albumin, decreased subcutaneous fat, edema, obesity, diabetes, incontinence, extreme age, immobility, and impaired immune responses all increase susceptibility of the skin to injury. Chronic corticosteroids exacerbate this problem. Shock and other hypoperfusion states decrease blood flow to the skin, also impairing normal healing. In addition, the skin is subject to an array of physical trauma in the ICU. These traumas include perforation by needles and catheters, shear stress during bed transfers and repositionings, abrasions resulting from dressing adhesives, and pressure from orthopedic devices and other surfaces contacting the skin.

The first step is minimizing physical trauma to the skin when performing procedures and applying or removing dressings. Give attention to improving the peripheral perfusion and nutritional status of the patient. In general, turn sedated patients (with or without paralysis) every 2 hours to avoid the development of pressure ulcers.

Specific Integumentary Conditions

Pressure Ulcers

Pressure ulcers occur from immobility or appliances in contact with the skin (see Table 42.1, Chapter 42). The Agency for Health Care Policy and Research has developed comprehensive guidelines for the problem of pressure ulcers. Prevention and treatment of pressure ulcers are described in Chapter 42.