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psychological outcomes and reduces symptoms of post‐traumatic stress disorder (Kress et al,
2003 Level III‐2). Contrary to initial concerns, DIS is not associated with an increased risk of
myocardial ischemia even in high‐risk patients (Kress et al, 2007 Level III‐1).

9.8.1 Pain assessment in the intensive care unit
Assessment of pain in the ICU is difficult. The most important index of pain is the patient’s own
subjective experience, but it is frequently impossible to quantify this because of the presence
of an endotracheal tube, or decreased conscious state due to illness or coadministered
sedative agents. In 17 trauma patients admitted to an ICU, 95% of doctors and 81% of nurses
felt that the patients had adequate analgesia whereas 74% of patients rated their pain as
moderate or severe (Whipple et al, 1995 Level IV).
Traditional subjective scales including the VAS or numerical rating scale (NRS) are not
applicable to the unresponsive patient. Instead, the observation of behavioural and
physiological responses may be the only information available to modify pain management
(Puntillo et al, 1997 Level IV; Puntillo et al, 2002 Level IV; Chong & Burchett, 2003).
A new behavioural pain scale has been described and validated for the evaluation of pain in
sedated, mechanically ventilated, unresponsive patients (Aissaoui et al, 2005 Level III‐1; Payen et
al, 2001 Level III‐1). A ‘critical‐care pain observation tool’ that is based upon the response to
noxious stimuli has undergone validation in diverse critically ill patient subgroups (Gelinas et al,
2009 Level III‐2).
The available data support self‐rating where possible, and where not, a nurse‐administered
NRS combined with the Behavioural Pain Scale (Ahlers et al, 2008 Level III‐3).
The use of formal pain/ agitation assessment and subsequent treatment decreased the
incidence overall of pain (63% vs 42%) and agitation (29% vs 12%). These findings were
associated with a decrease in the duration of mechanical ventilation (Chanques et al, 2006
Level III‐1). There were similar findings in critically ill trauma patients, where a formalised
analgesia‐delirium‐sedation protocol shortened duration of ventilation, ICU and hospital stay
while also decreasing total sedative doses (Robinson et al, 2008 Level III‐3).

9.8.2 Non-pharmacological measures
Much of the discomfort associated with a prolonged admission to intensive care can be
alleviated by holistic nursing care. Attention to detail with positioning, pressure care, CHAPTER 9
comfortable fixation of invasive devices, care in the management of secretions and excretions,
minimisation of noise from spurious alarms and unnecessary equipment (such as the uncritical
application of high‐flow mask oxygen) can substantially lessen the burden of discomfort for
the patient (Aaron et al, 1996; Chong & Burchett, 2003 Level IV; Puntillo et al, 2004 Level III‐3).
Maintenance of a day/night routine (lighting and activity) is thought to aid sleep quality
(Horsburgh, 1995). A flexible and liberal visiting policy should decrease the pain of separation
from family and friends. Physiotherapy maintains range of movement of joints and slows
deconditioning while massage can trigger a relaxation response leading to improved sleep.

9.8.3 Pharmacological treatment
The mainstay of treatment of acute pain in the ICU remains parenteral opioid analgesia
(Shapiro et al, 1995; Hawryluck et al, 2002). Morphine is usually the first choice, but it is relatively
contraindicated in the presence of renal impairment because of possible accumulation of its
active metabolites. Pethidine is rarely used in the ICU because of concerns about accumulation
of norpethidine, especially in the presence of renal dysfunction or prolonged exposure, and
because of its potential interaction with several drugs (eg tramadol, monoamine oxidase
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