Guide to Pain Management in Low-Resource Settings

What issues must be considered in this case for 
intensive care and afterwards?
•  Sources of pain (exacerbating factors)
• Eff ects of untreated pain (advantages of adequate 
pain relief, disadvantages of excessive analgesics 
or sedatives)
•  Assessment of pain and sedation
•  Aims of therapy
•  Techniques of pain management (routes for phar-
macological agents, analgesics, anxiolytics, and 
local anesthetic techniques)
•  Adjuncts to pharmacological agents (managing 
the ICU environment, reducing other sources of 
discomfort, alternative measures, psychological 
measures)
Th
  e majority of patients requiring intensive care 
will suff er pain, of varying intensity, during their stay. 
Despite knowledge since the early 1970s that pain is of-
ten the worst memory for patients surviving intensive 
care, in recent multicenter studies up to 64% of patients 
still said they were often in moderate to severe pain 
while in the ICU. Th
  e experiences of patients who did 
not survive their ICU stay remain unknown. Patients 
who were in ICU for longer periods reported greater in-
tensity of pain.
What are the sources of pain?
•  Primary pathology, such as burns, traumatic inju-
ries, fractures, wounds (surgical or traumatic)
•  Complications of the original condition or new 
problems, such as bowel perforation or break-
down of bowel anastomosis causing peritonitis, 
ischemic bowel, pancreatitis

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  orp and Sabu James
•  Other symptoms, such as abscesses, skin infl am-
mation, wound infection, rashes, itches
•  Support systems and monitoring—peripheral and 
central intravenous line insertions and sites, cath-
eters, drains, regular suctioning, physiotherapy, 
dressing changes
•  Tissue hypoxia as a result of low cardiac output, 
low oxygen saturation, or a sharp fall in hemoglo-
bin may result in myocardial ischemia
•  Painful joints, pressure points, pain on changing 
position in bed
What exacerbating factors may increase pain 
perception?
• Fear in strange surroundings associated with 
helplessness and lack of control
•  Inability to remember or understand the situation 
resulting in intensive care
•  Anxiety and uncertainty about oneself, one’s fam-
ily, and about the present and the future
• 
Background aggravations—noise, machine 
alarms, phones ringing
•  Ongoing activity through the night, other pa-
tients being admitted or resuscitated
•  Inability to communicate, to move, to change po-
sition
•  Lack of sleep, disturbed sleep patterns
• Other sensations:—thirst, hunger, hot, cold, 
cramps, itching, nausea
•  Fatigue after surgery; even after uncomplicated 
surgery, fatigue is normal
•  Boredom and lack of distraction
Addressing these aspects will make the pain it-
self more tolerable and manageable.
What are the eff ects of untreated pain?
•  Pain induces increased sympathetic drive, result-
ing in cardiovascular changes (increased cardiac 
work and oxygen consumption).
•  An increased stress hormone response results in 
catabolism, with sodium and water retention and 
hyperglycemia, which in turn leads to immuno-
suppression and delayed wound healing.
• Ineff ective cough and retention of secretions, re-
sulting in reduced oxygenation, infection.
•  Chest wounds and abdominal incisions decrease 
chest wall and abdominal movements, which may 
delay weaning from ventilation, increase the risk 
of chest infection, and prolong ICU stay.
•  Pain in itself will result in poor-quality sleep.
What are the advantages of adequate pain 
relief?
•  Improved tolerance of endotracheal tube, me-
chanical ventilation, tracheal suctioning, and oth-
er distressing maneuvers.
•  During weaning and after extubation, if chest ex-
cursion is limited by pain, adequate analgesia will 
result in larger tidal volumes, better gas exchange, 
improved sputum clearance, and cooperation 
with physiotherapy.
•  Reduction in the stress response.
•  Less disturbing memories of therapy in the ICU.
What is the compromise between too much 
analgesia and too little?
Th
  e middle ground, to gain the benefi ts without the dis-
advantages can only be achieved by regular assessment 
of pain along with a “sedation  vacation” (a break from 
sedation) and adjustment of the regime on a daily basis.
How can you assess pain and sedation?
Even under normal circumstances, assessment and 
quantifi cation of pain are diffi
  cult. Th
 ese diffi
  culties are 
obviously far greater in the patient in the ICU, with an 
endotracheal tube often present, preventing speech and 
empathic discussion. A state of paralysis in an aware pa-
tient should be avoided in the ICU just as in the operat-
ing room, as this is a terrifying experience for a patient. 
If the patient is paralysed, it is important to ensure that 
adequate sedation and analgesics are given to avoid a 
patient who is awake but unable to move!
If the patient is able to speak, a routine history 
about the pain and its severity can be taken. A patient 
who is able to understand, but unable to speak, may 
be able to gesture or to indicate severity on a simple 
evaluation tool such as a visual analogue scale (VAS) 
or numeric rating scale (NRS). Th
  e NRS is a 10-point 
scale: the patient chooses a number from 0 to 10, with 
10 being the worst pain imaginable. Where no com-
munication is possible, signs of sympathetic drive can 
be noted—tachycardia, hypertension, and lacrimation. 
Clinical practice guidelines state: “Patients who cannot 
communicate should be assessed through subjective 
observation of pain related behaviors (movement, facial 
expression and posturing) and physiological indicators 
(heart rate, blood pressure and respiratory rate) and the 
change in these variables following analgesic therapy.”

Pain Management in the Intensive Care Unit
285
Pain is exacerbated by movement, which may 
evoke pain of a quite diff erent character. Moving, turn-
ing the patient, and the eff ects of endotracheal tube suc-
tion and physiotherapy give valuable information about 
the eff ectiveness of analgesia.
For children, scales have been developed spe-
cifi cally for neonatal and pediatric use, e.g., the Riley In-
fant Pain Scale: 
Whatever method of assessment is selected, it 
should be regular. Both the patient and the response to 
drugs are constantly changing, so drugs and doses need 
regular adjustment.
What are the main problems for Joe in the 
intensive care unit?
•  Being heavily sedated and ventilated, and thus 
unable to communicate
•  Being critically ill, with multiple injuries includ-
ing lung contusions and possible head injury
•  Experiencing massive blood loss, massive trans-
fusion, and coagulopathy
• Having hypothermia
• Having anuria
•  Experiencing multiple sources of pain: intercostal 
drains, fractured ribs, elbow and knee wounds, 
and a laparotomy wound
What are the aims of therapy?
Th
  e objective should be a cooperative, pain-free patient, 
which implies that the patient is not unduly sedated.
Th
 e United Kingdom Intensive Care Society 
guidelines on sedation state the following:
1) All patients must be comfortable and pain free: 
Analgesia is thus the fi rst aim.
2) Anxiety should be minimized. Th
  is is diffi
  cult as 
anxiety is an appropriate emotion. Th
  e most important 
way to reduce anxiety is to provide compassionate and 
considerate care; communication is an essential part of 
care.
3) Patients should be calm, cooperative, and able to 
sleep when undisturbed. Th
  is does not mean that they 
must be asleep at all times.
4) Patients must be able to tolerate appropriate or-
gan system support. Th
  us, patients with very poor gas 
exchange, particularly those requiring inverse I:E ra-
tios or the initial stages of permissive hypercapnia, may 
need neuromuscular blockade. Th
  e use of a nerve stim-
ulator to monitor the extent of neuromuscular blockade 
may be useful in some situations.
5) Patients must never be paralysed and awake.
Pain management in                          
the intensive care unit
What techniques of pain management              
are available?
Most intensive care patients will require analgesia. In 
1995, the Society of Critical Care Medicine published 
practice parameters for intravenous analgesia and seda-
tion in the ICU. Morphine and fentanyl were the pre-
ferred analgesic agents, and midazolam or propofol were 
recommended for short-term sedation, with propofol 
being the agent of choice for rapid awakening. More re-
cently, sedative and analgesic practice in ICUs in Europe 
has been surveyed; opioids are the drugs most common-
ly used for pain relief, usually by infusion, with morphine 
being the most widely used. Shorter-acting fentanyl and 
alfentanil, as well as ultra-short-acting remifentanil, are 
also used, but they are more expensive. Propofol and 
benzodiazepines are used for sedation, with diazepam, 
lorazepam, and midazolam all being widely used.
What are the available application routes for 
pharmacological agents?
Th
  e ideal route is intravenous, which is more reliable 
than the alternatives. Small frequent intravenous bolus 
Score
Facial Expression
Sleep
Movements
Cry
Touch
0
- Neutral
- Smiling, calm
- Sleeping quietly
- Moves easily
- None
- 
1
- Frowning
- Grimaces
- Restless
- Restless body 
movements
- Whimpering
- Winces with touch
2
- Clenched teeth
- Intermittent
- Moderate agita-
tion
- Crying
- Cries with touch
- Diffi
  cult to console
3
- Crying expression
- Prolonged, with 
periods of jerking 
or no sleep
- Th
 rashing, 
fl ailing
- Screaming, 
high-pitched
- Screams when touched
- Inconsolable

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Josephine M. Th
  orp and Sabu James
doses or an intravenous infusion are the best routes for 
analgesics. Th
  e latter avoids peaks and troughs but may 
result in accumulation. Bolus doses should be regular 
without waiting until another dose is obviously essen-
tial. In all situations, it is important to review the re-
quirement regularly, for example daily, by discontinuing 
the infusion or stopping the boluses. In this way, pain 
can be assessed, accumulation can be avoided, and the 
dose can be adjusted accordingly. Another important 
reason for discontinuing drugs and allowing the patient 
to recover from the eff ects is the great variations in drug 
handling in the critically ill patient. Th
  ere are a vari-
ety of explanations for this variation, but discontinuing 
drugs allows the eff ect to wear off  and reduces the ten-
dency to accumulation.
Gastrointestinal absorption can be unpre-
dictable, and absorption of opioids is poor. Rectal ad-
ministration, for drugs that are available in supposi-
tory form, may give better absorption, although the 
side eff ects of the enteral route remain. Some classes 
of analgesics have only become available in parenteral 
form relatively recently. Intravenous nonsteroidal an-
ti-infl ammatory agents (NSAIDs) and, more recently, 
paracetamol (acetaminophen) are available as intrave-
nous formulations.
What would be a good choice                                   
of analgesia for Joe?
• 
Paracetamol/acetaminophen (intravenous, if 
available, or via nasogastric tube regularly)
• Nonsteroidal analgesics (via nasogastric tube) 
given regularly (after coagulopathy has resolved), 
combined with gastric protection agents
•  Opioids (preferably as a continuous intravenous 
infusion)
•  Nerve blocks (single-shot nerve blocks or epidu-
ral analgesia)
What to bear in mind when using opioid 
analgesics in the intensive care unit
Morphine and fentanyl are the most commonly used 
analgesics in Europe according to a survey in 2001; 
morphine has the advantage of being cheap. It is 
longer acting than synthetic opioids but also more 
inclined to accumulate. Elderly patients are more 
sensitive, as are those with renal or hepatic impair-
ment. The potent active metabolite, morphine-6-
glucuronide, can accumulate in renal failure, resulting 
in continued sedation, failure to breathe, or failure to 
wake up. This contraindication also applies to dia-
morphine and papaveretum. In renal impairment, if 
there is no alternative, the dose and dosing interval 
should be reduced.
Systemic eff ects of opioids within the context of 
intensive care are:
•  Central nervous system: morphine, diamorphine, 
and papaveretum have sedative properties, but 
excessive doses would be required to achieve se-
dation.
•  Respiratory system: all opiates depress respira-
tion in a manner proportionate to the pain relief 
obtained. Th
  is is not a major issue in a ventilated 
patient. Some cough-suppressant eff ect can be an 
advantage in the intubated patient.
• Cardiovascular system: given in small doses, 
there is usually little eff ect on blood pressure.
•  Gastrointestinal system: opiates have a gut an-
timotility eff ect and so may exacerbate paralytic 
ileus and constipation. Nausea and vomiting are 
well-known side eff ects of morphine.
•  Other side eff ects: pruritis can be a distress-
ing side eff ect for the patient. Addiction is not 
a problem with the use of opiates in severe pain 
and is not a concern in patients who have sur-
vived intensive care. However, withdrawal symp-
toms and signs are possible after several days of 
continuous therapy or if therapy is stopped sud-
denly. An initial reduction of 30% followed by 
a 10% reduction every 12–24 hours thereafter 
should help to avoid withdrawal phenomena.
Th
  e systemic eff ects of other opiates are similar 
to those described above. Diamorphine or papaveretum 
could be used instead of morphine if more readily avail-
able. Fentanyl is a synthetic opioid that was introduced 
as a short-acting agent, but it can accumulate when giv-
en as an infusion in intensive care. It may be useful for 
short painful procedures. Alfentanil has the advantages 
of fentanyl quoted above. Its onset is faster than that of 
fentanyl, and even as a prolonged infusion, it is less cu-
mulative; it would be the drug of choice in renal impair-
ment. Like fentanyl, it is particularly useful for addition-
al short-term analgesia, lasting around 10–15 minutes. 
Unfortunately, it is much more expensive.
Remifentanil, although quite expensive, is cur-
rently used in the intensive care arena, especially for 
weaning and tube tolerance. It is rapidly metabolized 
and does not accumulate regardless of time or in renal 
or hepatic dysfunction.

Pain Management in the Intensive Care Unit
287
For less severe pain, pethidine and tramadol 
could be used. Pethidine/meperidine could be given by 
bolus doses for procedural pain relief, but not as an in-
fusion, because its metabolite can accumulate and is as-
sociated with twitching and seizures. Tramadol has the 
advantage of two mechanisms of action for pain relief—
opiate-like activity by binding to opiate receptors and 
inhibition of serotonin and norepinephrine reuptake by 
nerves, mainly in the spinal cord. It is relatively expen-
sive but avoids the problems of respiratory depression 
and gastrointestinal stasis. Rapid intravenous injection 
may cause seizures, and it is not advised in pregnancy 
or breastfeeding.
Buprenorphine  and  pentazocine are unsuited 
for analgesia in intensive care. If given in a suffi
  cient 
dose to cause respiratory depression, they are not reli-
ably reversible with naloxone. In addition, these agents 
antagonize other opioids because of powerful receptor 
binding, reversing the analgesic eff ect of other opioids 
by displacing them from receptors. Th
 us, they may 
precipitate opioid withdrawal symptoms and signs. 
Pentazocine can be associated with bizarre thoughts 
and hallucinations.
Other opioids include meptazinol and codeine. 
Meptazinol is claimed to cause less respiratory depres-
sion, but it can cause nausea. Intravenous injection 
needs to be slow. Codeine is used in mild to moderate 
pain and might have some eff ect as a cough suppres-
sant. It is usually given orally, though linctus could be 
given down a nasogastric tube. Actually, codeine is me-
tabolized in the liver into morphine and other products 
that cause relatively severe side eff ects.
How to reverse the eff ects of opioids                    
if necessary
Naloxone reverses all opioid eff ects, so both respira-
tory depression and pain relief are reversed (for bu-
prenorphine and pentazocine, see above). Too much 
naloxone given too quickly and reversing analgesia 
may result in restlessness, hypertension, and arrhyth-
mias and has been known to precipitate cardiac ar-
rest in a sensitive patient. If possible, dilute naloxone 
to 0.1 mg/mL and titrate, giving 0.5 mL of the diluted 
solution at a time to achieve the required degree of re-
versal, so that respiration becomes adequate and some 
analgesia continues. Naloxone has a shorter duration 
of action than many opiates, and the patient may be-
come renarcotized. Repeat doses of naloxone or an in-
fusion may be required.
What nonopioid analgesics are options              
for analgesia in the intensive care unit?
Nonopioid analgesics used in combination with an 
opioid achieve better-quality pain relief. Although 
some intravenous and intramuscular preparations are 
available, these agents are mostly given by the enteral 
route if gastrointestinal function permits adequate ab-
sorption. Some are available in suppository form or as 
a liquid suspension, which can be given down a naso-
gastric tube.
Paracetamol/acetaminophen is a non-narcotic 
analgesic with useful antipyretic action as well. It is 
useful in mild to moderate pain and has an additive ef-
fect if given with an opiate. It is available as dispersible 
tablets, as an oral suspension, and in suppository form. 
It has no anti-infl ammatory activity and so avoids the 
side eff ects of nonsteroidal anti-infl ammatory  drugs 
(NSAIDs).  Clonidine,  an alpha-2-adrenergic agonist, 
can be used to augment both the sedative and analge-
sic eff ects of opioids. A dramatic reduction in opioid 
requirements and the attendant side eff ects has been 
reported with low-dose clonidine. Diclofenac, ketopro-
fen, ibuprofen, and other NSAIDS are good for bone 
pain and for soft-tissue pain in young patients without 
asthma or renal impairment and can reduce opioid re-
quirements. Oral, nasogastric, intravenous, and rec-
tal routes can be used. Regardless of route, they cause 
gastric irritation. Hence, prophylactic treatment for 
gastric ulceration should be given. However, the signif-
icant side eff ects of NSAIDs in intensive care have to 
be considered: they can cause bronchospasm, may pre-
cipitate or exacerbate a bleeding tendency, cause gas-
trointestinal bleeding from mucosal ulceration (exac-
erbated by platelet inhibition), or lead to development 
of renal impairment or worsening of renal failure, 
particularly when other risk factors are present, such 
as hypotension, hypertension, or diabetes. NSAIDs 
should be used with caution in older patients due to 
a higher incidence of gastric complications and renal 
impairment. Aspirin, indomethacin, and cyclooxygen-
ase (COX)-2 inhibitors are not recommended for use 
in the ICU due to a plethora of side eff ects.
What about using ketamine                                     
in the intensive care unit?
Good analgesia can be achieved with low-dose ket-
amine. It tends not to be used for background analgesia 
in intensive care in the United Kingdom, though it may 
be used for short procedures. Some studies have shown 

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Josephine M. Th
  orp and Sabu James
that ketamine reduces opioid requirements in surgical 
intensive care patients. Th
  e dose range for avoiding psy-
chomimetic side eff ects is 0.2 to 0.5 mg/kg body weight. 
If using S-ketamine, the dose range has to be divided by 
two. Long-term use is possible. Ketamine could perhaps 
be the analgesic of choice in patients with a history of 
bronchospasm to have the benefi t of bronchodilator 
activity without contributing to arrhythmias, if amino-
phylline is also required. Where expensive analgesics 
are not available, ketamine may have a slightly greater 
role as an adjunct in pain relief in intensive care. Also, 
predominantly neuropathic pain might be an indication, 
since the “normal” coanalgesics for neuropathic pain, 
e.g., amitriptyline, carbamazepine, and gabapentin, are 
not available for parenteral use and have a delayed onset 
of action.
Can local-anesthetic techniques be used              
in the intensive care unit?
Intercostal nerve blocks, paravertebral blocks, epidural 
analgesia, transversus abdominis plane (TAP) blocks, 
femoral nerve blocks, and interscalene/brachial plexus 
blocks can be used as single shots or with catheters 
(not for intercostal blocks) for continuous infusion. To 
avoid nerve damage, nerve stimulators or ultrasound 
guidance should be used, if the patient is sedated and 
paresthesias cannot be communicated.  Regular co-
agulation profi le, full blood count, and platelet num-
bers should be noted before these procedures as re-
gional techniques are contraindicated in patients with 
a bleeding tendency such as anticoagulation, coagu-
lopathy, and thrombocytopenia. If a continuous tech-
nique with an indwelling catheter is used, this should 
be clearly labeled. A fi lter should be used to minimize 
or prevent infections.