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148 PART 2: General Management of the Patient

thoracic surgery). There is controversy over the benefits of epidural doses of sedative and analgesic medications administered to critically ill
versus intravenous fentanyl analgesia. Some studies have reported patients. As such, the RASS and SAS are preferable over the traditional
similar outcomes when these two strategies are compared, whereas Ramsay Sedation Score.
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others have reported more effective analgesia with thoracic epidural The evaluation of sedation adequacy remains an individual bedside
fentanyl. 36,37 In thoracic surgery patients, epidural fentanyl has been maneuver. The nurse’s input is critical because he or she often will notice
associated with better preservation of respiratory function compared changes from an optimal level of sedation. Armed with validated seda-
with intravenous fentanyl. These salutary effects may be related to the tion scales, clinicians may strive to administer sedatives and analgesics
catheter being located near the source of pain. to more concrete, reportable levels. Ideally, one would prefer a patient
whose indications for sedation as outlined earlier are met yet who
SEDATION remains fully communicative with bedside caregivers. Such a state of
sedation correlates with a Ramsay score of 2 or 3, a Sedation Agitation
Pain is a cause for anxiety in most ICU patients despite adequate analgesia. Scale score of 3 or 4, or a RASS score of 0 or −1. 38-43 This state of being
A state of critical illness and dependence on others for care alone can awake and communicative while sedatives are still infusing is achievable
invoke anxiety. Accordingly, sedation strategies must be incorporated to in some patients. However, in many patients the stress of critical illness
recognize and respond to this problem. precludes such a condition, and patients may require sedation and anal-
gesia to a point where constant communication is not possible.
■ ASSESSING ADEQUACY OF SEDATION troencephalogram (EEG) signal into a discreet scaled number from 0
The Bispectral Index Monitor, a device that processes the raw elec-
Assessing adequacy of sedation can be difficult because of its subjective (absence of cortical activity) to 100 (fully awake), has been evaluated
nature. Several sedation scales such as the Ramsay Sedation Score, the as a tool to monitor sedation in the ICU setting. Some have found this
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Sedation Agitation Scale (SAS), and the Richmond Agitation-Sedation device to reliably detect a patient’s level of consciousness under general
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Scale (RASS) (Table 22-1) have been developed. The Ramsay scoring anesthesia, although others have questioned the overall utility of this
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40
system is frequently referenced in clinical investigations of sedation. device for preventing awareness. Preliminary data suggest a reason-
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While it has the benefit of simplicity, it does not effectively measure qual- able correlation between the bispectral index and the sedation agitation
ity or degree of sedation with regard to the goals outlined earlier and scale, as well as the RASS ; however, this device has not been evaluated
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46
43
has never been validated objectively. Sedation scales such as the SAS extensively in the ICU and awaits more extensive validation before its
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and the RAS have been tested extensively for validity and reliability. 39,40,43 role in the critical care setting is established. 7,47,48
The RASS is perhaps the most extensively evaluated scale. It has been Recently, the occurrence of delirium in mechanically ventilated ICU
validated for ability to detect changes in sedation status over consecutive patients has been shown to be associated with higher 6-month mortal-
days of ICU care, as well as against constructs of level of consciousness ity even after adjusting for severity of illness and the use of sedatives
and delirium. Furthermore, this scale has been shown to correlate with or analgesic medications. Higher benzodiazepine doses have been
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reported to be an independent risk factor for transition to delirium.
6
Additionally, higher benzodiazepines doses have been documented as an
TABLE 22-1 Richmond Agitation-Sedation Scale (RASS) independent risk factor for worse cognitive impairment, specifically,
Score Term Description executive function scores at 3 months after ICU discharge. Notably,
neither of the other sedative or opioid agents utilized in this study nega-
+4 Combative Overtly combative or violent, immediate danger to staff
tively affected executive outcomes. The Confusion Assessment Method
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+3 Very agitated Pulls on or removes tubes or catheters or is aggressive for diagnosing delirium has been modified for the ICU (the CAM-ICU)
+2 Agitated Frequent nonpurposeful movement or ventilator dys- and has been validated (see Chapter 82). 5
synchrony
+1 Restless Restless, anxious, or apprehensive but movements not ■ STRATEGIES FOR ADMINISTERING SEDATIVES IN THE ICU
aggressive or vigorous
When drug therapy is being decided, it is important to acknowledge
0 Alert and calm that no single drug can achieve all the indications for sedation and
−1 Drowsy, but has sustained (>10 seconds) awakening, analgesia in the ICU; therefore, a combination of drugs, each titrated
with eye opening in response to verbal command to specific end points, is the most effective strategy. Not all patients
manifest anxiety and agitation in the same way. Accordingly, therapy
−2 Light sedation Awakens briefly (<10 seconds) with eye contact to
verbal command should be patient specific, when possible, using a structured approach.
This may allow lower doses of individual drugs and reduce problems of
−3 Moderate sedation Any movement, except eye contact, in response to drug accumulation. In the ICU, sedatives and analgesics almost always
command are administered by the intravenous route. Both continuous infusion
−4 Deep sedation No response to voice, but any movement to physical and intermittent bolus techniques have been advocated. While continu-
stimulation ous infusions of sedatives may reduce rapid fluctuations in the level of
−5 Unarousable No response sedation, accumulation of drugs resulting in prolongation of mechanical
ventilation and ICU stay has been described. Intermittent administra-
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Procedure tion of sedatives and analgesics may increase demands on nursing time,
1. Observe patient. Is patient alert and calm (score 0)? potentially distracting attention away from other patient care issues.
Does patient have behavior that is consistent with restlessness or agitation (score +1 to +4 using Other perceived benefits of continuous sedative infusions include a
the criteria listed above, under Description)?
2. If patient is not alert, in a loud speaking voice state patient’s name, and direct patient to open eyes more consistent level of sedation with greater levels of patient comfort.
and look at speaker. Repeat once if necessary. Can prompt patient to continue looking at speaker. The convenience of this strategy for both patients and care givers is
Patient has eye opening and eye contact, which is sustained for more than 10 seconds (score −1). likely the greatest reason for its popularity.
Patient has eye opening and eye contact, but this is not sustained for 10 seconds (score −2). Ideally, strategies for sedation and analgesia in critically ill patients
3. If patient does not respond to voice, physically stimulate patient by shaking shoulder and then rub- should adhere to pharmacokinetic and pharmacodynamic principles.
bing sternum if there is no response to shaking shoulder. Unfortunately, ICU patients frequently exhibit unpredictable alterations
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Patient has any movement to physical stimulation (score −4). in pharmacology, so precise recommendations or guidelines for drug
Patient has no response to voice or physical stimulation (score −5). administration are not possible. Patient and drug characteristics have

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