PAIN IN ICU
Update in Diagnosis and
Management
Redefinition of Pain
1.Pulse Pain:
2.Blood pressure
3.Temperature
The Fifth
4.Respiratory rate Vital Sign™
All medical personnel must be able to assess pain at all times
3
Pain Pathways
Process of the pain disease
Acute pain + insufficient pain therapy
Collapse of the body's pain defenses
Central
sensitization
Pain memory
Pain disease
5
Sandkühler, J.: Preventing Pain Memory. MMW 2002; Special edition 2
Pain Assessment in ICU
Pain assessment in unconscious patients is a major challenge for healthcare
providers.
CPOT and BPS have acceptable discriminant validity in differentiating
nonnociceptive and nociceptive procedural pain although the effect size of CPOT is
larger than that of BPS. Although both instruments have low reliability, the
reliability of BPS is better.
Pain Etiology in ICU
Critical Care Pain Observasion Tool
(CPOT)
The CPOT was developed by Gelinas et al.35 in French, and later
translated into and validated in other languages.
The tool was designed to detect pain in critically ill patients and
includes 4 behavioral categories — facial expressions, body
movements, muscle tension, compliance with a ventilator (for
intubated patients) or verbalization (for extubated patients).
According to the data reported by Gelinas et al, 35, the cut-off point is
2–3, while a score of > 2 indicates the occurrence of pain.
The scale is a good tool in order to differentiate between pain-related
procedures (e.g. changes in body position) and painless procedures.
Behavioral Pain Scale
(BPS)
The BPS was developed by Payen et al. in order to assess pain in
unconscious mechanically ventilated patients.
The scale is based on three types (ranges) of behavior:
facial expressions
movements of the upper extremities
compliance with a ventilator.
Total score varies from 3 to 12 •
≤3 no pain.
4-5 mild pain.
6-11 an unacceptable amount of pain.
≥12 maximum pain.
Target score < 5
Pain Treatment
In 1986, the World Health Organization (WHO) proposed the WHO analgesic ladder to
provide adequate pain relief for cancer patients
This analgesic path has undergone several modifications over the years and is currently
applied for managing cancer pain but also acute and chronic non-cancer painful
conditions.
Multimodal Analgesia
1
Crews JC. JAMA. 2002;288:629-632.
2
Samad TA et al. Trends Mol Med. 2002;8:390-396.
3
Atcheson R et al. Management of Acute and Chronic Pain. London, England: BMJ Books; 1998:23-50.
Benefits of Multimodal Pain Therapy
• Reduced doses of
OPIOIDS
each analgesic
• Improved pain
+ Potentiation relief due to
synergistic or
additive effects
NSAIDs, • May reduce
acetaminophe
n,
severity of side
Anesthetic effects of each
local nerve drug
blocks
Kehlet H et al. Anesth Analog. 1993;77:1048-1056.
1
OPIOID
- Systemic Multimodal
- Epidural
- Subarach
Ketamin, Tramadol
Analgesia
Pain
COX-2, COX-3 LOCAL ANESTHETIC
- Epidural
MODULATION -Subarachnoid
Descending
modulation Dorsal Horn -Peripheral nerve block
Ascending Dorsal root ganglion
input
TRANSMISSION LA
COX-1
COX-2
Spinothalamic
Peripheral
tract TRANSDUCTION
nerve
Trauma
Peripheral
nociceptors
Analgosedation
Analgosedation, also known as analgesia-first sedation or analgesia-based
sedation, describes the practice of targeting pain and discomfort in an
intensive care unit (ICU) before utilising a sedative agent.
Many ICU patients were over sedated and undertreated for their pain.
Critically ill patients commonly experience pain at rest and with routine
intensive care procedures, with pain being reported in up to 77% of
ICU patients.
The Richmond Agitation Sedation Scale the most important tool that is frequently
used. Patients who have score of 1–4 are in state of restless to combative and
needs sedation. Those having scores -5 – 0 are in state of unarousable to alert and
calm so that do not need sedation.
Sedatives are given to hundreds of thousands of mechanically
ventilated critically ill patients worldwide every year.
Clinical practice guidelines and reviews on the sedation of
mechanically ventilated ICU patients recommend light sedation and
avoidance of benzodiazepines, leaving propofol or dexmedetomidine
as the preferred sedatives.
To overcome these challenges, the combination of dexmedetomidine
and propofol is common practice in many countries and has been
recently recommended.
In ventilated critically ill younger adults sedated with a combination
of dexmedetomidine and propofol infusions to achieve targeted deep
sedation, the preferential use of incremental doses of propofol or
dexmedetomidine was associated with divergent (reduced and
increased, respectively) 90-day mortality.
Dexmedetomidine
Dexmedetomidine is a parenteral selective α2 agonist with sedative
properties. It appears to be more selective for the α2 receptor than
clonidine.
Dexmedetomidine has been suggested as having neuroprotective
effects, including protecting the brain from the toxic effects of
anesthetic agents.
Moreover, some have indicated that dexmedetomidine may have
“renoprotective” qualities. Additional studies are needed to evaluate
these claims more fully.
The recommended initial loading dose is 1 mcg/kg intravenously over
10 min with a maintenance infusion rate of 0.2 to 0.7 mcg/kg/h.
Dexmedetomidine has a rapid onset and terminal half-life of 2 h.
According to Pain, Agitation/Sedation, Delirium, Immobility, and Sleep
disruption (PADIS) guidelines,1 light sedation is recommende for
adults undergoing mechanical ventilation (MV).
Light Sedation + Pain Control shorter time to extubation, lower
incidence of tracheostomy compared to deep sedation.
During MV with dexmedetomidine sedation, the use of remifentanil
was associated with an approximately 25% greater proportion of time
under light sedation than the proportion obtained with fentanyl.
In order to guarantee a better analgesia and reduce the adverse side effects, it’s useful
the association of opioids with adjuvant medications.
Non-opioid analgesics can improve the overall efficacy of analgesia and/or reduce
opioid requirements in ICU patients. A systematic review and meta-analysis published
in 2020.
Analgesic medications in ICU patients: dexmetedomidine, nonsteroidal anti-
inflammatory drugs (NSAIDs) (including diclofenac, indomethacin, and ketoprofen),
ketamine, nefopam, gabapentin carbamazepine, clonidine, magnesium sulfate,
pregabalin. It has been described that the association of opioids with adjuvant is able
to reduced pain in ICU patients.
Paracetamol is one of the most widely prescribed medications within critical care, with
a large observational trial reporting that 64% of intensive care unit (ICU) patients
received paracetamol during their stay.
Ketamine is unique among anesthetics and analgesics. The drug is a rapid-acting
general anesthetic that produces an anesthetic state.
Ketamine has been administered as a coanalgesic in palliative care patients in
addition to opioids and coadjuvant drugs.
Despite being a safe and widely used drug, many physicians, such as
intensivists and those practicing in emergency care, are not aware of the
current clinical applications of ketamine.
Ketamine has been administered as a coanalgesic in palliative care patients in
addition to opioids and coadjuvant drugs.
For analgesia, doses of ketamine are 0.25 to 0.5mg/kg bolus IV (may be repeated if
necessary, at a maximum dose of 2mg/kg in a 30-minute period) and 0.05 to
0.4mg/kg/h in continuous infusion
As presented before, ketamine has been widely used in many clinical situations but
is not frequently used in patients with brain injury.
Nevertheless, these findings have not been confirmed in more recent studies.
In patients with severe brain injury, ketamine in combination with midazolam was
not associated with increased intracranial pressure or decreased cerebral
perfusion pressure.
Moreover, in another trial with patients with intracranial hypertension undergoing
mechanical ventilation, ketamine successfully reduced ICP and avoided untoward
ICP elevations during distressing interventions without lowering blood pressure
and cerebral perfusion pressure.
Non Pharmacological Pain
Management in ICU
There have been several non-pharmacologic methods that have gained increasing
evidence over the last several years. The SCCM ICU Liberation Bundle recommends
four primary non-pharmacologic methods.
Massage Therapy for ICU patients typically involves massage on the back, feet
and/or hands. Depending on the patient’s clinical status, hands-only massage is
also acceptable.
Cold therapy in ICU patients for pain management has been described by applying
gauze-wrapped ice packs to procedural areas pre-procedure
Music or sound therapy has been associated with moderate decreases in pain
scores in ICU patients.
Relaxation therapy includes techniques such as guided imagery, breathing
exercises, biofeedback and self-hypnosis, with guided imagery and breathing
exercises being the most frequently used in critically ill patients.
